The anaerobic digestion of sludge has recently received increased interest because of the potential to transform organic matter into methane‐rich biogas. However, digested sludge, the residue produced in that process...The anaerobic digestion of sludge has recently received increased interest because of the potential to transform organic matter into methane‐rich biogas. However, digested sludge, the residue produced in that process, still contains high levels of heavy metals and other harmful substances that might make traditional disposal difficult. We have devised a facile method of converting digested sludge into a mesoporous material that acts as an effective and stable heterogeneous catalyst for the photo‐Fenton reaction. A comparison of the removal of rhodamine B under different conditions showed that FAS‐1‐350, which was synthesized by mixing the digested sludge with a 1 mol/L（NH4）2Fe（SO4）2 solution followed by calcination at 350 °C, exhibited the best catalytic activity owing to its faster reaction rate and lower degree of Fe leaching. The results indicate that Fe^（2＋）‐loaded catalysts have significant potential to act as stable and efficient heterogeneous promoters for the photo‐Fenton reaction, with better performance than Fe^3＋‐loaded catalysts because the Fe（II）/Fe（III）compounds formed in the calcination process are necessary to sustain the Fenton reaction. This protocol provides an alternative, environmentally friendly method of reusing digested sludge and demonstrates an easily synthesized mesoporous material that effectively degrades azo dyes.展开更多
The changes in the physical characteristics of unconditioned and conditioned anaerobic digested sludge （ADS） biosolids, such as capillary suction time （CST）, yield stress, average size and fractal dimensions, were...The changes in the physical characteristics of unconditioned and conditioned anaerobic digested sludge （ADS） biosolids, such as capillary suction time （CST）, yield stress, average size and fractal dimensions, were investigated through a CST test, transient and dynamic rheological test and image analysis. The results showed that the optimum polymer dose range was observed when CST or its reciprocal value was employed as an indicator. There were good correlations between the yield stresses determined from both a controlled shear stress test and a strain amplitude sweep test. The yield stress and storage modulus （G＇） increased as the polymer dose increased in most cases. A frequency sweep test revealed that polymer conditioning could extend the frequency sweep ranges for their elastic behaviors over viscous behaviors as well as the gel-like structure in the linear viscoelastic range. These results implied that more deformation energy was stored in this rigid structure, and that elastic behavior became increasingly dominant with the addition of the polymer in most cases, In addition, both the average sizes and two-dimensional fractal dimensions for conditioned ADS biosolids presented a similar up-climax-down variation trend as the polymer doses increased, whereas the critical polymer doses at the highest average sizes or two-dimensional fractal dimensions, were different. Correlation analysis revealed that the conditioned ADS dewaterability was not correlated with the yield stresses, while the average sizes or the two-dimensional fractal dimensions for conditioned ADS biosolids could be taken as the indication parameters for ADS dewaterability.展开更多
The composition and effects of solution conditions on the physicochemical properties of the stratification components of extracellular polymeric substances （EPS） in anaerobic digested sludge were determined. The tot...The composition and effects of solution conditions on the physicochemical properties of the stratification components of extracellular polymeric substances （EPS） in anaerobic digested sludge were determined. The total EPS in anaerobic digested sludge were extracted by the cation exchange resin method. Another EPS extraction method, the ceutrifugation and sonication technique was employed to stratify the EPS into three fractions： slime, loosely bound （LB）-EPS, and tightly bound （TB）-EPS from the outside to the inside of the anaerobic digested sludge. Proteins and polysaccharides were dispersed uniformly across the different EPS fractions, and humic-like substances were mainly partitioned in the slime, with TB-EPS second. Protein was the major constituent of the LB-EPS and TB-EPS, and the corresponding ratios ranged from 54.0% to 65.6%. The hydrophobic part in the EPS chemical components was primarily comprised of protein and DNA, while the hydrophilic part was mainly composed of polysaccharide. In the slime, the hydrophobic values of several EPS chemical components （protein, polysaccharide, humic-like substances and DNA） were all below 50%. The protein/polysaccharide ratio had a significant influence on the Zeta potentials and isoelectric point values of the EPS： the greater the protein/polysaccharide ratio of the EPS was, the greater the Zeta potential and the higher the isoelectric point value were. All Zeta potentials of the EPS showed a decreasing trend with increasing pH. The corresponding isoelectric point values （pH） were 2.8 for total EPS, 2.2 for slime, 2.7 for LB-EPS, and 2.6 for TB-EPS. As the ionic strength increased, the Zeta potentials sharply increased and then gradually became constant without charge reversal. In addition, as the temperature increased （〈 40℃）, the apparent viscosity of the EPS decreased monotonically and then gradually became stable between 40 and 60℃.展开更多
A lab-scale intermittently aerated sequencing batch reactor（IASBR）was applied to treat anaerobically digested swine wastewater（ADSW）to explore the removal characteristics of veterinary antibiotics.The removal rate...A lab-scale intermittently aerated sequencing batch reactor（IASBR）was applied to treat anaerobically digested swine wastewater（ADSW）to explore the removal characteristics of veterinary antibiotics.The removal rates of 11 veterinary antibiotics in the reactor were investigated under different chemical organic demand（COD）volumetric loadings,solid retention times（SRT）and ratios of COD to total nitrogen（TN）or COD/TN.Both sludge sorption and biodegradation were found to be the major contributors to the removal of veterinary antibiotics.Mass balance analysis revealed that greater than 60%of antibiotics in the influent were biodegraded in the IASBR,whereas averagely 24%were adsorbed by sludge under the condition that sludge sorption gradually reached its equilibrium.Results showed that the removal of antibiotics was greatly influenced by chemical oxygen demand（COD）volumetric loadings,which could achieve up to 85.1%±1.4%at 0.17±0.041 kg COD/m-3/day,while dropped to 75.9%±1.3%and 49.3%±12.1%when COD volumetric loading increased to 0.65±0.032 and1.07±0.073 kg COD/m-3/day,respectively.Tetracyclines,the dominant antibiotics in ADSW,were removed by 87.9%in total at the lowest COD loading,of which 30.4%were contributed by sludge sorption and 57.5%by biodegradation,respectively.In contrast,sulfonamides were removed about 96.2%,almost by biodegradation.Long SRT seemed to have little obvious impact on antibiotics removal,while a shorter SRT of 30–40 day could reduce the accumulated amount of antibiotics and the balanced antibiotics sorption capacity of sludge.Influent COD/TN ratio was found not a key impact factor for veterinary antibiotics removal in this work.展开更多
Biogas production generates digested slurry as a byproduct. It can be used as a fertilizer especially after its conversion into digested liquid. A pot based study was conducted in order to evaluate the effect of the a...Biogas production generates digested slurry as a byproduct. It can be used as a fertilizer especially after its conversion into digested liquid. A pot based study was conducted in order to evaluate the effect of the application of digested liquid on CH4 and N2O flux, and plant biomass in paddy. Analysis revealed that digested liquid treated soils released more CH4 compared to ammonium sulphate and the control. Ammonium sulphate treated soil emitted the highest N20 whereas digested liquid application decreased its emission significantly. Further, the cumulative emission over 101 d of the experiment was found to be higher for CHa （16.9 to 29.9 g m^-2） compared to N20 （-49.3 to 18.9 mg m^-2） for all treatments. Digested liquid application had positive impact on plant variables such as panicle number and weight of panicles. This study suggests that digested liquid application significantly decrease N20 emission and increase CH4 emission possibly due to affecting the availability of organic C in the soil to microbial activity for methanogenesis. Another possibility for enhancing CH4 emission by following biogas digested liquid could be attributed to the increase in plant biomass.展开更多
Digested effluent of manure (DEM) produced by biogas-plants contains many macro- and micro-nutrients. In an experiment conducted in southern Kyushu (Japan), forage crops cultivated after receiving DEM and chemical fer...Digested effluent of manure (DEM) produced by biogas-plants contains many macro- and micro-nutrients. In an experiment conducted in southern Kyushu (Japan), forage crops cultivated after receiving DEM and chemical fertilizers exhibited similar dry matter yields. From a logistical standpoint, however, DEM in liquid form is difficult to handle and apply due to the low concentration of nutrients. To overcome this shortcoming, we prepared dehydrated DEM (DDEM) by adding DEM to cattle manure without disturbing the manure fermentation process. The objective of this research was to evaluate the effect of DDEM on dry matter yield and nitrogen recovery rate in annual dual-cropping systems (summer crop of maize or sorghum and winter crop of Italian ryegrass) that are typical of the region and to compare these results to commercial cattle manure alone, in combination with chemical fertilizer (CM or CM + CF), or no fertilizer application (NF). In both cropping systems, the DDEM treatment produced similar dry matter yields (2.6 to 3.02 kg·m-2) and apparent nitrogen recovery rates (43% to 53%) as the CM + CF and CM treatments. This suggests that DDEM can potentially replace chemical fertilizers and commercial cattle manure in the region.展开更多
Addition of digested sewage sludge at concentrations of 2% and 10% (v/v) to the water increased coughing rate in big head and tilapia (P<0.05). Ventilation rate was significantly decreased (P<0.05) in big head a...Addition of digested sewage sludge at concentrations of 2% and 10% (v/v) to the water increased coughing rate in big head and tilapia (P<0.05). Ventilation rate was significantly decreased (P<0.05) in big head and tilapia at sludge concentrations of 6% and 2% (v/v)respectively. Copper (Cu), cadmium (Cd) and zinc (Zn) are trace metals which are commonly found in sludge. Cu caused a significant increase (P<0.05) in coughing rate in both tilapia and big head at concentrations of 0.3 and 0.2 μg/ml respectively. Zn caused significant increase (P<0.05) in coughing rate only in big head at 2 μg/ml. Neither fish responded to Cd of up to 2μg/ml in the water. However, when the levels of these trace metals in the digested sludge were measured, they were below that which can cause significant changes in the respiratory movements. Therefore, the changes in ventilation and coughing rates after addition of sludge may be due to the presence of substances other than these metals. The results of this experiment provides a guideline to control the level of sludge that can be used in rearing these fresh water fish in ponds展开更多
The reversibility of the structure and dewaterability of broken anaerobic digested sludge（ADS）is important to ensure the efficiency of sludge treatment or management processes.This study investigated the effect of c...The reversibility of the structure and dewaterability of broken anaerobic digested sludge（ADS）is important to ensure the efficiency of sludge treatment or management processes.This study investigated the effect of continuous strong shear（CSS）and multipulse shear（MPS）on the zeta potential,size（median size,d（50））,mass fractal dimension（DF）,and capillary suction time（CST）of ADS aggregates.Moreover,the self-regrowth（SR）of broken ADS aggregates during slow mixing was also analyzed.The results show that raw ADS with d（50） of 56.5μm was insensitive to CSS–SR or MPS–SR,though the size slightly decreased after the breakage phase.For conditioned ADS with d（50） larger than 600μm,the breakage in small-scale surface erosion changed to large-scale fragmentation as the CSS strength increased.In most cases,after CSS or MPS,the broken ADS had a relatively more compact structure than before and d（50） is at least 200μm.The CST of the broken fragments from optimally dosed ADS increased,whereas that corresponding to overdosed ADS decreased.MPS treatment resulted in larger and more compact broken ADS fragments with a lower CST value than CSS.During the subsequent slow mixing,the broken ADS aggregates did not recover their charge,size,and dewaterability to the initial values before breakage.In addition,less than 15%self-regrowth in terms of percentage of the regrowth factor was observed in broken ADS after CSS at average velocity gradient no less than 1905.6 sec^（-1）.展开更多
Aqueous ammonia was used to pretreat wheat straw to improve biodegradability and provide nitrogen source for enhancing biogas production. Three doses of ammonia(2%, 4%, and 6%, dry matter) and three moisture contents(...Aqueous ammonia was used to pretreat wheat straw to improve biodegradability and provide nitrogen source for enhancing biogas production. Three doses of ammonia(2%, 4%, and 6%, dry matter) and three moisture contents(30%, 60%, and 80%, dry matter) were applied to pretreat wheat straw for 7 days. The pretreated wheat straws were anaerobically digested at three loading rates(50, 65, and 80 g·L-1) to produce biogas. The results indicated that the wheat straw pretreated with 80% moisture content and 4% ammonia achieved the highest methane yield of 199.7 ml·g-1(based on per unit volatile solids loaded), with shorter digestion time(T80) of 25 days at the loading rate of 65 g·L-1compared to untreated one. The main chemical compositions of wheat straw were also analyzed. The cellulose and hemicellulose contents were decomposed by 2%-20% and 26%-42%, respectively,while the lignin content was hardly removed, cold-water and hot-water extracts were increased by 4%-44%, and12%-52%, respectively, for the ammonia-pretreated wheat straws at different moisture contents. The appropriate C/N ratio and decomposition of original chemical compositions into relatively readily biodegradable substances will improve the biodegradability and biogas yield.展开更多
Objective To compare the ileal digestibility of protein and amino acids in parental rice and rice genetically modified with sck gene. Methods Six experimental swines were surgically fixed with a simple T-cannula at th...Objective To compare the ileal digestibility of protein and amino acids in parental rice and rice genetically modified with sck gene. Methods Six experimental swines were surgically fixed with a simple T-cannula at the terminal ileum and fed with parental rice and rice genetically modified with sck gene alternately. The ileum digesta were collected and analyzed for determination of apparent and true digestibility of protein and amino acids. Results The apparent and true digestibility of protein was similar in these two types of rice. Except for the apparent digestibility of lysine, there was no difference in the apparent and true digestibility of the other 17 amino acids. Conclusion The digestibility of protein and amino acids is not changed by the insertion of foreign gene, so it can meet the request of ＂substantial equivalence＂ in digestibility of protein and amino acids.展开更多
To examine the effect of mechanical processing for plant-based materials on antioxidant properties during digestion,relationships between the size of pulverized plant tissue and changes in antioxidant activities durin...To examine the effect of mechanical processing for plant-based materials on antioxidant properties during digestion,relationships between the size of pulverized plant tissue and changes in antioxidant activities during simulated in vitro digestion were investigated.The citrus peel tissue was pulverized and classified into four powder fractions followed their particle size distributions as 125−180m,180−355m,355−500m and 500−710m.These fractions were regarded as a plant tissue model with various degrees of cell damages.Powder samples were collected during the digestion and measured their particle sizes and colors.Besides,total phenolic content and antioxidant activities of digested fluid were also evaluated.The results showed that the powder color of smaller particles were significantly changed than the bigger ones.The bio-properties of digested fluid for the bigger particle sizes comparatively retained more than smaller ones at the simulated gastric stage.It also showed mostly stable during simulated gastric or small intestinal digestion stage.This suggested that the release of bioactive compounds from plant tissues during digestion could be related to their structural attributes such as degrees of cell damages which could be affected by processing methods and conditions.展开更多
Research on marine bioactive peptides has mainly focused on characterization of peptides in hydrolysates prepared with commercial industrial enzymes and the usefulness of such hydrolysates in health and functional foo...Research on marine bioactive peptides has mainly focused on characterization of peptides in hydrolysates prepared with commercial industrial enzymes and the usefulness of such hydrolysates in health and functional foods. However, a relevant question is whether digestion of fish proteins with gastrointestinal proteases per se generates peptides that also can have health promoting properties and can reduce, e.g., diabetes 2, inflammation and hypertension either in relation to gastrointestinal digestion or as alternative to industrial proteases. The aim of the study was to investigate hydrolysates obtained from in vitro sequential digestion of salmon muscle and skin with gastrointestinal proteases including pepsin, pancreatic and pancreatic ＋ mucosal proteases for their ability to scavenge ABTS^＋ radicals and inhibit activity of angiotensin I-converting enzyme （ACE） and dipeptidyl peptidase 4 （DPP-4）. Furthermore, it was the aim to study the inhibitory mechanism and stability towards ACE and DPP-4 activity. Analysis of〈 10 kDa hydrolysates showed that gastrointestinal proteases generated peptides with clear radical scavenging activity and DPP-4 and ACE inhibiting activity as well. Hydrolysates from pepsin digestion exhibited the lowest ECso values for radical scavenging activity and ACE inhibition, whereas ECso increased in hydrolysates after subsequent digestion with pancreatic and mucosal proteases. Interestingly, ECso values for the DPP-4 inhibition were hardly affected by sequential digestion. Inhibition modes for the muscle hydrolysates were both competitive and non-competitive, but prolonged incubation showed that the inhibitory properties were unstable and therefore they were probably digested as competitive substrates by gastrointestinal proteases.展开更多
A three-year (2006-2008) field experiment was conducted at Swift Current and Star City in Saskatchewan to determine the short-term in-fluence of land-applied anaerobically digested swine manure (ADSM), conventionally ...A three-year (2006-2008) field experiment was conducted at Swift Current and Star City in Saskatchewan to determine the short-term in-fluence of land-applied anaerobically digested swine manure (ADSM), conventionally treated swine manure (CTSM) and N fertilizer on total organic C (TOC), total organic N (TON), light fraction organic C (LFOC), light fraction organic N (LFON) and pH in the 0 - 7.5 and 7.5 - 15 cm soil layers, and ammonium-N, nitrate-N, extractable P, exchangeable K and sulphate-S in the 0 - 15, 15 - 30, 30 - 60, 60 - 90 and 90 - 120 cm soil layers. Treatments included spring and autumn applications of CTSM and ADSM at a 1x rate (10,000 and 7150 L·ha-1, respectively) applied each year, a 3x rate (30,000 and 21,450 L·ha-1, respectively) applied once at the beginning of the experiment, plus a treatment receiving commercial fertilizer (UAN at 60 kg·N·ha-1·yr-1) and a zero-N control. There was no effect of swine manure rate, type and application time on soil pH. Mass of TOC and TON in the 15 cm soil layer increased significantly with swine manure application compared to the control, mainly at the Swift Current site, with greater increases from 3x rate than 1x rate (by 2.21 Mg·C·ha-1 and 0.167 Mg·N·ha-1). Compared to the control, mass of LFOC and LFON in the 15 cm soil layer increased with swine manure application at sites, with greater increases from 3x rate than 1x rate (by 287 kg·C·ha-1 and 26 kg·N·ha-1 at Star City, and by 194 kg·C·ha-1 and 19·kg·N ha-1 at Swift Current). Mass of TOC and TON in soil layer was tended to be greater with ADSM than CTSM, but mass of LFOC and LFON in soil was greater with CTSM than ADSM. Mass of TOC, TON, LFOC and LFON in soil also increased with annual N fertilizer application compared to the control (by 3.2 Mg·C·ha-1 for TOC, 0.195 Mg·N·ha-1 for TON, 708 kg·C·ha-1 for LFOC and 45 kg·N·ha-1 for LFON). In conclusion, our findings suggest that the quantity and quality of organic C and N in soil can be affected by swine manure rate and type, and N fertilization even after three years, most likely by influencing inputs of C and N through crop residue, and improve soil quality.展开更多
Anaerobic digestion is a promising technology that could provide an option for managing animal waste with reduced greenhouse gas emissions. A three-year (2006-2008) field experiment was conducted at Star City, Saskatc...Anaerobic digestion is a promising technology that could provide an option for managing animal waste with reduced greenhouse gas emissions. A three-year (2006-2008) field experiment was conducted at Star City, Saskatchewan, Canada, to compare the effects of land-applied anaerobically digested swine manure (ADSM), conventionally treated swine manure (CTSM) and N fertilizer on grain yield of barley, applied N use efficiency (ANUE, kg·grain·kg-1 of applied N·ha-1), ammonia (NH3) volatilization and nitrous oxide (N2O) emissions. Treatments included spring and autumn applications of CTSM and ADSM at a 1x rate (10,000 and 7150 L·ha-1, respectively) applied every year, a 3x rate (30,000 and 21,450 L·ha-1, respectively) applied once at the beginning of the experiment, plus a treatment receiving commercial fertilizer (UAN at 60 kg·N·ha-1·yr-1) and a zero-N control. There was a significant grain yield response of barley to applied N in all three years. The ANUE of ADSM or CTSM applied once at the 3x rate were lower than annual applications at the 1x rate (grain yield by 595 kg·ha-1 and NFUE by 6 kg·grain·kg-1 of applied N·ha-1). On average, agronomic performance of ADSM was similar to CTSM. The APNU of N fertilizer was greater than the 3x rate but lower than the 1x rate of ADSM or CTSM. Ammonia loss from ADSM was similar to CTSM, except for much higher loss of NH3-N from CTSM at the 3x rate applied in the autumn (8100 g·N·ha-1) compared to the other treatments (1100 - 2600 g·N·ha-1). The percentage of applied N lost as N2O gas was generally higher for treatments receiving CTSM (4.0%) compared to ADSM (1.4%). In conclusion, the findings suggest that ADSM is equal or slightly better than CTSM in terms of agronomic performance, but has lower environmental impact.展开更多
This article summarizes the recent progress of nutrient removal from wastewater via microalgae.Removal of nitrogen and phosphorous compounds from wastewater are of great importance,while those compounds are suitable f...This article summarizes the recent progress of nutrient removal from wastewater via microalgae.Removal of nitrogen and phosphorous compounds from wastewater are of great importance,while those compounds are suitable for growth of some microalgae species.Such a combination provides more opportunities for anaerobic digestion facilities,which are producing large amount of wastewater with high nitrogen and phosphorous contents.However,in order to optimize and maximize the performance and durability of the nutrient removal process,it is suggested that the basic principles about nitrogen and phosphorous migration should be investigated thoroughly,especially from the fundamentals of substance transfer mechanism between water environment and algal cells.展开更多
To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subseq...To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subsequently,the effect of SBOS on microbial community structure and metabolites was studied by 16S rRNA gene sequencing and untargeted metabolomics based on liquid chromatography-mass spectrometry.Results showed that SBOS was not easily enzymolyzed during simulated digestion and could reach the large intestine through the digestive system.The significant decrease in the molecular mass of SBOS after in vitro fermentation indicated its utilization by the gut microbiota,which increased the contents of short-chain fatty acids and lactic acid,thereby reducing the pH of the fermentation broth.Moreover,the core community was found to consist of Blautia,Lactobacillaceae,and Pediococcus.SBOS up-regulated beneficial differential metabolites such as myo-inositol,lactose,and glucose,which were closely related to galactose,amino sugar,and nucleotide sugar metabolism.This study will provide a reference for exploring the relationship between the gut microbiota and the metabolites of SBOS,and provide a basis for the development and application of SBOS as an ingredient for functional products.展开更多
The whole process of biofuel production from Desmodesmus sp.EJ 8-10 cultivated in anaerobic digested wastewater(ADW)under the optimal temperature was evaluated by using the method of Life Cycle Assessment(LCA).The ene...The whole process of biofuel production from Desmodesmus sp.EJ 8-10 cultivated in anaerobic digested wastewater(ADW)under the optimal temperature was evaluated by using the method of Life Cycle Assessment(LCA).The energy efficiency and environment emissions were under considerable for the corresponding parametric study.The functional unit was 1 kg microalgae.It was concluded that the harvest stage was responsible for the main energy consumption during the microalgal whole pyrolysis process.The energy conversion efficiency of the whole process was larger than 1,which indicated that the process was profitable.The environmental impact of the whole process was 1165.67 mPET2000,among which the primary impact on the environment was eutrophication that accounts for 57.36%,followed by photochemical ozone synthesis(22.56%),acidification(17.36%);and global warming(2.73%),respectively.展开更多
This study aimed to investigate potential methane production through anaerobic co-digestion of rice straw and digested swine manure with different total solids.The research was carried out in bench scale with utilizin...This study aimed to investigate potential methane production through anaerobic co-digestion of rice straw and digested swine manure with different total solids.The research was carried out in bench scale with utilizing batch system.To evaluate the stability of anaerobic co-digestion process,the experiment was run in triplicate.The anaerobic co-digestion process was operated in 500 mL batch digesters under constant agitation speed and temperature.The agitation speed was maintained at 270 r/min.Temperature of the batch system was set and maintained at 35℃.Digested swine manure utilized in this experiment was obtained from semi-continuous digesters run at steady state condition,with 25 days of hydraulic retention time under mesophilic condition.Rice straw(RS)generated the highest methane production at 3% total solids(TS)which was around(1814±47.43)mL,where in this concentration,it had C:N ratio at 10.6:1.Rice straw obtained the highest methane yield at 3% TS,which was around(141.4±3.70)mL CH_(4)/g volatile solids(VS)added.Rice straw also had the highest chemical oxygen demand(COD)removal and VS reduction at 3% TS which were around(52.97%±1.46%)and(61.81%±1.04%),respectively.展开更多
This study was to characterise the undigested nutrients present along the gastrointestinal tract of birds offered common wheat-or maize-based diets,with the goal of optimising utilisation of enzymes to enhance digesti...This study was to characterise the undigested nutrients present along the gastrointestinal tract of birds offered common wheat-or maize-based diets,with the goal of optimising utilisation of enzymes to enhance digestive efficiency.Wheat-and maize-based diets were offered to 240 mixed-sex broilers(10 birds/pen;n=12)from 1 to 35 d postehatch.Digestibility of dry matter,starch,crude protein and nonstarch polysaccharides(NSP)were measured in the crop,gizzard,duodenum,jejunum,ileum,caeca and excreta at d 12 and 35 postehatch.Analysis of nutrient levels in the excreta presented that more than 30%of nutrients provided in the feed was wasted,irrespective of wheat or maize diet type.On average,92 g/kg crude protein,92 g/kg insoluble NSP and 14 g/kg oligosaccharides were not utilised by birds at d 12 postehatch.The quantity of water-insoluble NSP in the small intestine at d 12 was lower in birds offered the wheat-based diet compared to those fed the maize-based diet(P<0.05),with the reverse being true for water-soluble NSP(P<0.001).On average,84 g/kg crude protein,79 g/kg insoluble NSP and 9 g/kg oligosaccharides remained in the excreta at 35 d of age.At this time period,accumulation of feed in the gizzard was noted for birds offered both diets,but was more pronounced in those offered the maize-based diet(P<0.001).Birds offered the maize-based diet demonstrated improved utilisation of oligosaccharides compared to those fed the wheat-based diet at both d 12 and 35(P=0.087 and P=0.047,respectively).Protein utilisation in the jejunum and ileum was greater in birds offered the wheat-based diet compared to those fed the maize-based diet(P=0.004 and P<0.001,respectively).Thus,while both diets supported standard growth performance of birds,the degree and flow of nutrient disappearance along the gastrointestinal tract was influenced by cereal type and bird age.展开更多
A traditional sequencing batch reactor （SBR） and two intermittently aerated sequencing batch reactors （IASBRs） were parallelly operated for treating digested piggery wastewater. Their microbial communities were an...A traditional sequencing batch reactor （SBR） and two intermittently aerated sequencing batch reactors （IASBRs） were parallelly operated for treating digested piggery wastewater. Their microbial communities were analyzed, and the nitrogen removal performance was compared during the long term run. IASBRs demonstrated higher removal rates of total nitrogen （TN） and ammonium nitrogen （NH4＋ -N） than the SBR, and also demonstrated higher resistance against TN shock load. It was found that the more switch times between aerobic/anoxic in an IASBR, the higher the removal rates of TN and NH4＋ N. All the reactors were predominated by Thauera, Nitrosomonas and Nitrobacter, which were considered to be species of denitrifiers, ammonium oxidizing bacteria （AOB） and nitrite oxidizing bacteria （NOB）, respectively. However, the abundance and diversity was of great difference. Compared with SBR, IASBRs achieved higher abundance of denitrification related bacteria. IASBR 1# with four aerobic/anoxic switch times was detected with 25.63% of Thauera, higher than that in IASBR 2# with two aerobic/anoxic switch times （l 1.57% of Thauera）, and much higher than that in the SBR （only 6.19% of Thauera）. IASBR 2# had the highest percentage of AOB, while 1ASBR 1# had the lowest percentage. The denitrifiers abundance was significantly positive correlated with the TN removal rate. However, the NH4＋ N removal rate showed no significant correlation with the AOB abundance, but might relate to the AOB activity which was influenced by the average free ammonium （FA） concentration. Nitrobacter was the only NOB genus detectable in all reactors, and were less than 0.03%.展开更多
基金supported by the National Key Technology Research&Development Program of China(2014BAL02B02)the National Natural Science Foundation of China(51578397)~~
文摘The anaerobic digestion of sludge has recently received increased interest because of the potential to transform organic matter into methane‐rich biogas. However, digested sludge, the residue produced in that process, still contains high levels of heavy metals and other harmful substances that might make traditional disposal difficult. We have devised a facile method of converting digested sludge into a mesoporous material that acts as an effective and stable heterogeneous catalyst for the photo‐Fenton reaction. A comparison of the removal of rhodamine B under different conditions showed that FAS‐1‐350, which was synthesized by mixing the digested sludge with a 1 mol/L（NH4）2Fe（SO4）2 solution followed by calcination at 350 °C, exhibited the best catalytic activity owing to its faster reaction rate and lower degree of Fe leaching. The results indicate that Fe^（2＋）‐loaded catalysts have significant potential to act as stable and efficient heterogeneous promoters for the photo‐Fenton reaction, with better performance than Fe^3＋‐loaded catalysts because the Fe（II）/Fe（III）compounds formed in the calcination process are necessary to sustain the Fenton reaction. This protocol provides an alternative, environmentally friendly method of reusing digested sludge and demonstrates an easily synthesized mesoporous material that effectively degrades azo dyes.
基金supported by the National Natural Science Foundation of China (No. 51078035, 20977008)the Fundamental Research Funds for the Central Universities (No. BLJC200902, TD2010-5)+1 种基金the High-Tech Research and Development Program (863) of China (No. 2007AA06Z301)the Major Projects on Control and Rectification of Water Body Pollution (No. 2008ZX07422-002-004, 2008ZX07314-006)
文摘The changes in the physical characteristics of unconditioned and conditioned anaerobic digested sludge （ADS） biosolids, such as capillary suction time （CST）, yield stress, average size and fractal dimensions, were investigated through a CST test, transient and dynamic rheological test and image analysis. The results showed that the optimum polymer dose range was observed when CST or its reciprocal value was employed as an indicator. There were good correlations between the yield stresses determined from both a controlled shear stress test and a strain amplitude sweep test. The yield stress and storage modulus （G＇） increased as the polymer dose increased in most cases. A frequency sweep test revealed that polymer conditioning could extend the frequency sweep ranges for their elastic behaviors over viscous behaviors as well as the gel-like structure in the linear viscoelastic range. These results implied that more deformation energy was stored in this rigid structure, and that elastic behavior became increasingly dominant with the addition of the polymer in most cases, In addition, both the average sizes and two-dimensional fractal dimensions for conditioned ADS biosolids presented a similar up-climax-down variation trend as the polymer doses increased, whereas the critical polymer doses at the highest average sizes or two-dimensional fractal dimensions, were different. Correlation analysis revealed that the conditioned ADS dewaterability was not correlated with the yield stresses, while the average sizes or the two-dimensional fractal dimensions for conditioned ADS biosolids could be taken as the indication parameters for ADS dewaterability.
基金supported by the Fundamental Research Funds for the Central University (No.JC2011-1,TD2010-5)the National Natural Science Foundation of China(No. 51078035, 21177010)the Ph.D Programs Foundation of the Ministry of Education of China (No.20100014110004)
文摘The composition and effects of solution conditions on the physicochemical properties of the stratification components of extracellular polymeric substances （EPS） in anaerobic digested sludge were determined. The total EPS in anaerobic digested sludge were extracted by the cation exchange resin method. Another EPS extraction method, the ceutrifugation and sonication technique was employed to stratify the EPS into three fractions： slime, loosely bound （LB）-EPS, and tightly bound （TB）-EPS from the outside to the inside of the anaerobic digested sludge. Proteins and polysaccharides were dispersed uniformly across the different EPS fractions, and humic-like substances were mainly partitioned in the slime, with TB-EPS second. Protein was the major constituent of the LB-EPS and TB-EPS, and the corresponding ratios ranged from 54.0% to 65.6%. The hydrophobic part in the EPS chemical components was primarily comprised of protein and DNA, while the hydrophilic part was mainly composed of polysaccharide. In the slime, the hydrophobic values of several EPS chemical components （protein, polysaccharide, humic-like substances and DNA） were all below 50%. The protein/polysaccharide ratio had a significant influence on the Zeta potentials and isoelectric point values of the EPS： the greater the protein/polysaccharide ratio of the EPS was, the greater the Zeta potential and the higher the isoelectric point value were. All Zeta potentials of the EPS showed a decreasing trend with increasing pH. The corresponding isoelectric point values （pH） were 2.8 for total EPS, 2.2 for slime, 2.7 for LB-EPS, and 2.6 for TB-EPS. As the ionic strength increased, the Zeta potentials sharply increased and then gradually became constant without charge reversal. In addition, as the temperature increased （〈 40℃）, the apparent viscosity of the EPS decreased monotonically and then gradually became stable between 40 and 60℃.
文摘A lab-scale intermittently aerated sequencing batch reactor（IASBR）was applied to treat anaerobically digested swine wastewater（ADSW）to explore the removal characteristics of veterinary antibiotics.The removal rates of 11 veterinary antibiotics in the reactor were investigated under different chemical organic demand（COD）volumetric loadings,solid retention times（SRT）and ratios of COD to total nitrogen（TN）or COD/TN.Both sludge sorption and biodegradation were found to be the major contributors to the removal of veterinary antibiotics.Mass balance analysis revealed that greater than 60%of antibiotics in the influent were biodegraded in the IASBR,whereas averagely 24%were adsorbed by sludge under the condition that sludge sorption gradually reached its equilibrium.Results showed that the removal of antibiotics was greatly influenced by chemical oxygen demand（COD）volumetric loadings,which could achieve up to 85.1%±1.4%at 0.17±0.041 kg COD/m-3/day,while dropped to 75.9%±1.3%and 49.3%±12.1%when COD volumetric loading increased to 0.65±0.032 and1.07±0.073 kg COD/m-3/day,respectively.Tetracyclines,the dominant antibiotics in ADSW,were removed by 87.9%in total at the lowest COD loading,of which 30.4%were contributed by sludge sorption and 57.5%by biodegradation,respectively.In contrast,sulfonamides were removed about 96.2%,almost by biodegradation.Long SRT seemed to have little obvious impact on antibiotics removal,while a shorter SRT of 30–40 day could reduce the accumulated amount of antibiotics and the balanced antibiotics sorption capacity of sludge.Influent COD/TN ratio was found not a key impact factor for veterinary antibiotics removal in this work.
文摘Biogas production generates digested slurry as a byproduct. It can be used as a fertilizer especially after its conversion into digested liquid. A pot based study was conducted in order to evaluate the effect of the application of digested liquid on CH4 and N2O flux, and plant biomass in paddy. Analysis revealed that digested liquid treated soils released more CH4 compared to ammonium sulphate and the control. Ammonium sulphate treated soil emitted the highest N20 whereas digested liquid application decreased its emission significantly. Further, the cumulative emission over 101 d of the experiment was found to be higher for CHa （16.9 to 29.9 g m^-2） compared to N20 （-49.3 to 18.9 mg m^-2） for all treatments. Digested liquid application had positive impact on plant variables such as panicle number and weight of panicles. This study suggests that digested liquid application significantly decrease N20 emission and increase CH4 emission possibly due to affecting the availability of organic C in the soil to microbial activity for methanogenesis. Another possibility for enhancing CH4 emission by following biogas digested liquid could be attributed to the increase in plant biomass.
文摘Digested effluent of manure (DEM) produced by biogas-plants contains many macro- and micro-nutrients. In an experiment conducted in southern Kyushu (Japan), forage crops cultivated after receiving DEM and chemical fertilizers exhibited similar dry matter yields. From a logistical standpoint, however, DEM in liquid form is difficult to handle and apply due to the low concentration of nutrients. To overcome this shortcoming, we prepared dehydrated DEM (DDEM) by adding DEM to cattle manure without disturbing the manure fermentation process. The objective of this research was to evaluate the effect of DDEM on dry matter yield and nitrogen recovery rate in annual dual-cropping systems (summer crop of maize or sorghum and winter crop of Italian ryegrass) that are typical of the region and to compare these results to commercial cattle manure alone, in combination with chemical fertilizer (CM or CM + CF), or no fertilizer application (NF). In both cropping systems, the DDEM treatment produced similar dry matter yields (2.6 to 3.02 kg·m-2) and apparent nitrogen recovery rates (43% to 53%) as the CM + CF and CM treatments. This suggests that DDEM can potentially replace chemical fertilizers and commercial cattle manure in the region.
文摘Addition of digested sewage sludge at concentrations of 2% and 10% (v/v) to the water increased coughing rate in big head and tilapia (P<0.05). Ventilation rate was significantly decreased (P<0.05) in big head and tilapia at sludge concentrations of 6% and 2% (v/v)respectively. Copper (Cu), cadmium (Cd) and zinc (Zn) are trace metals which are commonly found in sludge. Cu caused a significant increase (P<0.05) in coughing rate in both tilapia and big head at concentrations of 0.3 and 0.2 μg/ml respectively. Zn caused significant increase (P<0.05) in coughing rate only in big head at 2 μg/ml. Neither fish responded to Cd of up to 2μg/ml in the water. However, when the levels of these trace metals in the digested sludge were measured, they were below that which can cause significant changes in the respiratory movements. Therefore, the changes in ventilation and coughing rates after addition of sludge may be due to the presence of substances other than these metals. The results of this experiment provides a guideline to control the level of sludge that can be used in rearing these fresh water fish in ponds
基金supported by the Fundamental Research Funds for the Central UniversitiesChina(No.YX2013-20)+1 种基金the National Natural Science Foundation of China(Nos.51478041,51078035,and 21177010)the Technology Foundation for Selected Overseas Chinese Scholar,Ministry of Personnel of China,and the Major Projects on Control and Rectification of Water Body Pollution(Nos.2012ZX07105-002-03 and 2013ZX07202-010)
文摘The reversibility of the structure and dewaterability of broken anaerobic digested sludge（ADS）is important to ensure the efficiency of sludge treatment or management processes.This study investigated the effect of continuous strong shear（CSS）and multipulse shear（MPS）on the zeta potential,size（median size,d（50））,mass fractal dimension（DF）,and capillary suction time（CST）of ADS aggregates.Moreover,the self-regrowth（SR）of broken ADS aggregates during slow mixing was also analyzed.The results show that raw ADS with d（50） of 56.5μm was insensitive to CSS–SR or MPS–SR,though the size slightly decreased after the breakage phase.For conditioned ADS with d（50） larger than 600μm,the breakage in small-scale surface erosion changed to large-scale fragmentation as the CSS strength increased.In most cases,after CSS or MPS,the broken ADS had a relatively more compact structure than before and d（50） is at least 200μm.The CST of the broken fragments from optimally dosed ADS increased,whereas that corresponding to overdosed ADS decreased.MPS treatment resulted in larger and more compact broken ADS fragments with a lower CST value than CSS.During the subsequent slow mixing,the broken ADS aggregates did not recover their charge,size,and dewaterability to the initial values before breakage.In addition,less than 15%self-regrowth in terms of percentage of the regrowth factor was observed in broken ADS after CSS at average velocity gradient no less than 1905.6 sec^（-1）.
基金Supported by the National High Technology Research and Development Program of China(2008AA062401)the China-US International Cooperation Project(2011DFA90800)the Ministry of Science and Technology,China
文摘Aqueous ammonia was used to pretreat wheat straw to improve biodegradability and provide nitrogen source for enhancing biogas production. Three doses of ammonia(2%, 4%, and 6%, dry matter) and three moisture contents(30%, 60%, and 80%, dry matter) were applied to pretreat wheat straw for 7 days. The pretreated wheat straws were anaerobically digested at three loading rates(50, 65, and 80 g·L-1) to produce biogas. The results indicated that the wheat straw pretreated with 80% moisture content and 4% ammonia achieved the highest methane yield of 199.7 ml·g-1(based on per unit volatile solids loaded), with shorter digestion time(T80) of 25 days at the loading rate of 65 g·L-1compared to untreated one. The main chemical compositions of wheat straw were also analyzed. The cellulose and hemicellulose contents were decomposed by 2%-20% and 26%-42%, respectively,while the lignin content was hardly removed, cold-water and hot-water extracts were increased by 4%-44%, and12%-52%, respectively, for the ammonia-pretreated wheat straws at different moisture contents. The appropriate C/N ratio and decomposition of original chemical compositions into relatively readily biodegradable substances will improve the biodegradability and biogas yield.
文摘Objective To compare the ileal digestibility of protein and amino acids in parental rice and rice genetically modified with sck gene. Methods Six experimental swines were surgically fixed with a simple T-cannula at the terminal ileum and fed with parental rice and rice genetically modified with sck gene alternately. The ileum digesta were collected and analyzed for determination of apparent and true digestibility of protein and amino acids. Results The apparent and true digestibility of protein was similar in these two types of rice. Except for the apparent digestibility of lysine, there was no difference in the apparent and true digestibility of the other 17 amino acids. Conclusion The digestibility of protein and amino acids is not changed by the insertion of foreign gene, so it can meet the request of ＂substantial equivalence＂ in digestibility of protein and amino acids.
文摘To examine the effect of mechanical processing for plant-based materials on antioxidant properties during digestion,relationships between the size of pulverized plant tissue and changes in antioxidant activities during simulated in vitro digestion were investigated.The citrus peel tissue was pulverized and classified into four powder fractions followed their particle size distributions as 125−180m,180−355m,355−500m and 500−710m.These fractions were regarded as a plant tissue model with various degrees of cell damages.Powder samples were collected during the digestion and measured their particle sizes and colors.Besides,total phenolic content and antioxidant activities of digested fluid were also evaluated.The results showed that the powder color of smaller particles were significantly changed than the bigger ones.The bio-properties of digested fluid for the bigger particle sizes comparatively retained more than smaller ones at the simulated gastric stage.It also showed mostly stable during simulated gastric or small intestinal digestion stage.This suggested that the release of bioactive compounds from plant tissues during digestion could be related to their structural attributes such as degrees of cell damages which could be affected by processing methods and conditions.
文摘Research on marine bioactive peptides has mainly focused on characterization of peptides in hydrolysates prepared with commercial industrial enzymes and the usefulness of such hydrolysates in health and functional foods. However, a relevant question is whether digestion of fish proteins with gastrointestinal proteases per se generates peptides that also can have health promoting properties and can reduce, e.g., diabetes 2, inflammation and hypertension either in relation to gastrointestinal digestion or as alternative to industrial proteases. The aim of the study was to investigate hydrolysates obtained from in vitro sequential digestion of salmon muscle and skin with gastrointestinal proteases including pepsin, pancreatic and pancreatic ＋ mucosal proteases for their ability to scavenge ABTS^＋ radicals and inhibit activity of angiotensin I-converting enzyme （ACE） and dipeptidyl peptidase 4 （DPP-4）. Furthermore, it was the aim to study the inhibitory mechanism and stability towards ACE and DPP-4 activity. Analysis of〈 10 kDa hydrolysates showed that gastrointestinal proteases generated peptides with clear radical scavenging activity and DPP-4 and ACE inhibiting activity as well. Hydrolysates from pepsin digestion exhibited the lowest ECso values for radical scavenging activity and ACE inhibition, whereas ECso increased in hydrolysates after subsequent digestion with pancreatic and mucosal proteases. Interestingly, ECso values for the DPP-4 inhibition were hardly affected by sequential digestion. Inhibition modes for the muscle hydrolysates were both competitive and non-competitive, but prolonged incubation showed that the inhibitory properties were unstable and therefore they were probably digested as competitive substrates by gastrointestinal proteases.
文摘A three-year (2006-2008) field experiment was conducted at Swift Current and Star City in Saskatchewan to determine the short-term in-fluence of land-applied anaerobically digested swine manure (ADSM), conventionally treated swine manure (CTSM) and N fertilizer on total organic C (TOC), total organic N (TON), light fraction organic C (LFOC), light fraction organic N (LFON) and pH in the 0 - 7.5 and 7.5 - 15 cm soil layers, and ammonium-N, nitrate-N, extractable P, exchangeable K and sulphate-S in the 0 - 15, 15 - 30, 30 - 60, 60 - 90 and 90 - 120 cm soil layers. Treatments included spring and autumn applications of CTSM and ADSM at a 1x rate (10,000 and 7150 L·ha-1, respectively) applied each year, a 3x rate (30,000 and 21,450 L·ha-1, respectively) applied once at the beginning of the experiment, plus a treatment receiving commercial fertilizer (UAN at 60 kg·N·ha-1·yr-1) and a zero-N control. There was no effect of swine manure rate, type and application time on soil pH. Mass of TOC and TON in the 15 cm soil layer increased significantly with swine manure application compared to the control, mainly at the Swift Current site, with greater increases from 3x rate than 1x rate (by 2.21 Mg·C·ha-1 and 0.167 Mg·N·ha-1). Compared to the control, mass of LFOC and LFON in the 15 cm soil layer increased with swine manure application at sites, with greater increases from 3x rate than 1x rate (by 287 kg·C·ha-1 and 26 kg·N·ha-1 at Star City, and by 194 kg·C·ha-1 and 19·kg·N ha-1 at Swift Current). Mass of TOC and TON in soil layer was tended to be greater with ADSM than CTSM, but mass of LFOC and LFON in soil was greater with CTSM than ADSM. Mass of TOC, TON, LFOC and LFON in soil also increased with annual N fertilizer application compared to the control (by 3.2 Mg·C·ha-1 for TOC, 0.195 Mg·N·ha-1 for TON, 708 kg·C·ha-1 for LFOC and 45 kg·N·ha-1 for LFON). In conclusion, our findings suggest that the quantity and quality of organic C and N in soil can be affected by swine manure rate and type, and N fertilization even after three years, most likely by influencing inputs of C and N through crop residue, and improve soil quality.
文摘Anaerobic digestion is a promising technology that could provide an option for managing animal waste with reduced greenhouse gas emissions. A three-year (2006-2008) field experiment was conducted at Star City, Saskatchewan, Canada, to compare the effects of land-applied anaerobically digested swine manure (ADSM), conventionally treated swine manure (CTSM) and N fertilizer on grain yield of barley, applied N use efficiency (ANUE, kg·grain·kg-1 of applied N·ha-1), ammonia (NH3) volatilization and nitrous oxide (N2O) emissions. Treatments included spring and autumn applications of CTSM and ADSM at a 1x rate (10,000 and 7150 L·ha-1, respectively) applied every year, a 3x rate (30,000 and 21,450 L·ha-1, respectively) applied once at the beginning of the experiment, plus a treatment receiving commercial fertilizer (UAN at 60 kg·N·ha-1·yr-1) and a zero-N control. There was a significant grain yield response of barley to applied N in all three years. The ANUE of ADSM or CTSM applied once at the 3x rate were lower than annual applications at the 1x rate (grain yield by 595 kg·ha-1 and NFUE by 6 kg·grain·kg-1 of applied N·ha-1). On average, agronomic performance of ADSM was similar to CTSM. The APNU of N fertilizer was greater than the 3x rate but lower than the 1x rate of ADSM or CTSM. Ammonia loss from ADSM was similar to CTSM, except for much higher loss of NH3-N from CTSM at the 3x rate applied in the autumn (8100 g·N·ha-1) compared to the other treatments (1100 - 2600 g·N·ha-1). The percentage of applied N lost as N2O gas was generally higher for treatments receiving CTSM (4.0%) compared to ADSM (1.4%). In conclusion, the findings suggest that ADSM is equal or slightly better than CTSM in terms of agronomic performance, but has lower environmental impact.
基金supported by Chinese National 13th five-year Plan for Key R&D Projects(2018YFD0400804)the Beijing Municipal Education Commission General Project(KM201810011002)+4 种基金the Research Foundation for Youth Scholars of Beijing Technology and Business University(PXM2018_014213_000033)the research was also supported by the National Natural Science Foundation of China(Grant No.51806242)the National Natural Science Foundation of China(No.71961024)the Chinese Universities Scientific Fund(No.2019TC010)the Chinese Universities Scientific Fund-Special Project of“Agricultural Mechanization and Equipment Engineering”for“Double First-Class”Initiative of College of Engineering,China Agricultural University.
文摘This article summarizes the recent progress of nutrient removal from wastewater via microalgae.Removal of nitrogen and phosphorous compounds from wastewater are of great importance,while those compounds are suitable for growth of some microalgae species.Such a combination provides more opportunities for anaerobic digestion facilities,which are producing large amount of wastewater with high nitrogen and phosphorous contents.However,in order to optimize and maximize the performance and durability of the nutrient removal process,it is suggested that the basic principles about nitrogen and phosphorous migration should be investigated thoroughly,especially from the fundamentals of substance transfer mechanism between water environment and algal cells.
文摘To investigate the in vitro digestion and fermentation properties of soybean oligosaccharides(SBOS)extracted from defatted soybean meal,the changes in monosaccharide composition and molecular mass were analyzed.Subsequently,the effect of SBOS on microbial community structure and metabolites was studied by 16S rRNA gene sequencing and untargeted metabolomics based on liquid chromatography-mass spectrometry.Results showed that SBOS was not easily enzymolyzed during simulated digestion and could reach the large intestine through the digestive system.The significant decrease in the molecular mass of SBOS after in vitro fermentation indicated its utilization by the gut microbiota,which increased the contents of short-chain fatty acids and lactic acid,thereby reducing the pH of the fermentation broth.Moreover,the core community was found to consist of Blautia,Lactobacillaceae,and Pediococcus.SBOS up-regulated beneficial differential metabolites such as myo-inositol,lactose,and glucose,which were closely related to galactose,amino sugar,and nucleotide sugar metabolism.This study will provide a reference for exploring the relationship between the gut microbiota and the metabolites of SBOS,and provide a basis for the development and application of SBOS as an ingredient for functional products.
基金This research was supported by the Beijing Municipal Natural Science Fund-Key project of science and technology plan of Beijing Education Committee(KZ201810011017)Beijing Municipal Education Commission General Project(KM201810011002)+4 种基金Chinese National 13th five-year Plan for Key R&D Projects(2018YFD0400804)the National Natural Science Foundation of China(Grant No.51806242 and No.41942006)Public Opening Project of the Key Laboratory of Development and Application of Rural Renewable Energy,Ministry of Agriculture,China(Grant No.2017008)the Chinese Universities Scientific Fund(Grant No.2019TC010)and the Chinese Universities Scientific Fund-Special Project for“Double First-Class”Initiative of College of Engineering-Agricultural Mechanization and Equipment Engineering,China Agricultural University.We also appreciate for the supports from Beijing Municipal Key Discipline of Biomass Engineering.
文摘The whole process of biofuel production from Desmodesmus sp.EJ 8-10 cultivated in anaerobic digested wastewater(ADW)under the optimal temperature was evaluated by using the method of Life Cycle Assessment(LCA).The energy efficiency and environment emissions were under considerable for the corresponding parametric study.The functional unit was 1 kg microalgae.It was concluded that the harvest stage was responsible for the main energy consumption during the microalgal whole pyrolysis process.The energy conversion efficiency of the whole process was larger than 1,which indicated that the process was profitable.The environmental impact of the whole process was 1165.67 mPET2000,among which the primary impact on the environment was eutrophication that accounts for 57.36%,followed by photochemical ozone synthesis(22.56%),acidification(17.36%);and global warming(2.73%),respectively.
基金funding the program in the Department of Biological and Agricultural Engineering,North Carolina State University(NCSU).
文摘This study aimed to investigate potential methane production through anaerobic co-digestion of rice straw and digested swine manure with different total solids.The research was carried out in bench scale with utilizing batch system.To evaluate the stability of anaerobic co-digestion process,the experiment was run in triplicate.The anaerobic co-digestion process was operated in 500 mL batch digesters under constant agitation speed and temperature.The agitation speed was maintained at 270 r/min.Temperature of the batch system was set and maintained at 35℃.Digested swine manure utilized in this experiment was obtained from semi-continuous digesters run at steady state condition,with 25 days of hydraulic retention time under mesophilic condition.Rice straw(RS)generated the highest methane production at 3% total solids(TS)which was around(1814±47.43)mL,where in this concentration,it had C:N ratio at 10.6:1.Rice straw obtained the highest methane yield at 3% TS,which was around(141.4±3.70)mL CH_(4)/g volatile solids(VS)added.Rice straw also had the highest chemical oxygen demand(COD)removal and VS reduction at 3% TS which were around(52.97%±1.46%)and(61.81%±1.04%),respectively.
基金We would like to thank BASF SE for their financial and academic support throughout this study。
文摘This study was to characterise the undigested nutrients present along the gastrointestinal tract of birds offered common wheat-or maize-based diets,with the goal of optimising utilisation of enzymes to enhance digestive efficiency.Wheat-and maize-based diets were offered to 240 mixed-sex broilers(10 birds/pen;n=12)from 1 to 35 d postehatch.Digestibility of dry matter,starch,crude protein and nonstarch polysaccharides(NSP)were measured in the crop,gizzard,duodenum,jejunum,ileum,caeca and excreta at d 12 and 35 postehatch.Analysis of nutrient levels in the excreta presented that more than 30%of nutrients provided in the feed was wasted,irrespective of wheat or maize diet type.On average,92 g/kg crude protein,92 g/kg insoluble NSP and 14 g/kg oligosaccharides were not utilised by birds at d 12 postehatch.The quantity of water-insoluble NSP in the small intestine at d 12 was lower in birds offered the wheat-based diet compared to those fed the maize-based diet(P<0.05),with the reverse being true for water-soluble NSP(P<0.001).On average,84 g/kg crude protein,79 g/kg insoluble NSP and 9 g/kg oligosaccharides remained in the excreta at 35 d of age.At this time period,accumulation of feed in the gizzard was noted for birds offered both diets,but was more pronounced in those offered the maize-based diet(P<0.001).Birds offered the maize-based diet demonstrated improved utilisation of oligosaccharides compared to those fed the wheat-based diet at both d 12 and 35(P=0.087 and P=0.047,respectively).Protein utilisation in the jejunum and ileum was greater in birds offered the wheat-based diet compared to those fed the maize-based diet(P=0.004 and P<0.001,respectively).Thus,while both diets supported standard growth performance of birds,the degree and flow of nutrient disappearance along the gastrointestinal tract was influenced by cereal type and bird age.
文摘A traditional sequencing batch reactor （SBR） and two intermittently aerated sequencing batch reactors （IASBRs） were parallelly operated for treating digested piggery wastewater. Their microbial communities were analyzed, and the nitrogen removal performance was compared during the long term run. IASBRs demonstrated higher removal rates of total nitrogen （TN） and ammonium nitrogen （NH4＋ -N） than the SBR, and also demonstrated higher resistance against TN shock load. It was found that the more switch times between aerobic/anoxic in an IASBR, the higher the removal rates of TN and NH4＋ N. All the reactors were predominated by Thauera, Nitrosomonas and Nitrobacter, which were considered to be species of denitrifiers, ammonium oxidizing bacteria （AOB） and nitrite oxidizing bacteria （NOB）, respectively. However, the abundance and diversity was of great difference. Compared with SBR, IASBRs achieved higher abundance of denitrification related bacteria. IASBR 1# with four aerobic/anoxic switch times was detected with 25.63% of Thauera, higher than that in IASBR 2# with two aerobic/anoxic switch times （l 1.57% of Thauera）, and much higher than that in the SBR （only 6.19% of Thauera）. IASBR 2# had the highest percentage of AOB, while 1ASBR 1# had the lowest percentage. The denitrifiers abundance was significantly positive correlated with the TN removal rate. However, the NH4＋ N removal rate showed no significant correlation with the AOB abundance, but might relate to the AOB activity which was influenced by the average free ammonium （FA） concentration. Nitrobacter was the only NOB genus detectable in all reactors, and were less than 0.03%.
