Recently,using anaerobic hydrolysis of waste activated sludge (WAS) to recover volatile fatty acids (VFAs) as carbon sources for denitrification has been widely studied,and the key is to solve the problem of improving...Recently,using anaerobic hydrolysis of waste activated sludge (WAS) to recover volatile fatty acids (VFAs) as carbon sources for denitrification has been widely studied,and the key is to solve the problem of improving the solubility and bioavailability of WAS organic matter.Considering the energy consumption and chemical cost,this paper used low-dose nanozero-valent iron (NZVI) coupled with low-intensity ultrasonication (US) to pretreat WAS,and explored the effects of different treatment sequences on the fragmentation of WAS flocs particles,the dissolution of organic matter,and the subsequent biofermentation conversion process.The results showed low-dose NZVI synchronized with low-intensity US (NZVIUS)worked best for WAS anaerobic fermentation.Compared with 2062 mg/L in control group,soluble chemical oxygen demand (SCOD) after NZVIUS treatment reached up to 2786 mg/L during the fermentation cycle,and the initial release rate of SCOD increased by 69%.The VFAs production was elevated from 1522 to 1940 mg COD/L.NZVIUS pretreatment promoted the solubilization of attached organic matter,manifested by the fragmentation of WAS flocs and cell lysis.At the same time,proteins and carbohydrates in the extracellular polymeric substances (EPS) had different types of migration and transformation,and transfer of EPS can contribute 35.6% to SCOD.Moreover,adding NZVI promoted PO_(4)^(3-)-P recovery in the fermentation supernatant by 22.3% more than in day 4 control.This study demonstrated that the NZVIUS pretreatment method can effectively improve the production of VFAs by WAS anaerobic fermentation,meeting the practical needs of wastewater plants.展开更多
[Objective] This research aimed to explore the method to increase conversion rate of pollen-tub pathway in Chinese cabbage.[Method] Chinese cabbage varieties Yuqing and No.03 were used as materials for the selection o...[Objective] This research aimed to explore the method to increase conversion rate of pollen-tub pathway in Chinese cabbage.[Method] Chinese cabbage varieties Yuqing and No.03 were used as materials for the selection of germination buffer and parameters for ultrasonication.[Result] The optimal buffer for pollen germination of Chinese cabbage was 200 g/L sucrose ＋ 100 mg/L boric acid ＋ 200 mg/L calcium nitrate,the preferred ultrasonic processing power was 150 W,processing time was 5 s,interval time was 5 s and processing frequency was 8.Three T1-generation plants were obtained through selection with 200 mg/L kanamycin.[Conclusion] This research laid foundation for the further genetic transformation of Chinese cabbage.展开更多
The chlorinated and fluorinated zeolite catalysts were prepared by the impregnation of zeolites( H-ZSM-5,H-MOR or H-Y) using two halogen precursors( ammonium chloride and ammonium fluoride) in this study. The influenc...The chlorinated and fluorinated zeolite catalysts were prepared by the impregnation of zeolites( H-ZSM-5,H-MOR or H-Y) using two halogen precursors( ammonium chloride and ammonium fluoride) in this study. The influence of ultrasonic irradiation was evaluated for optimizing both halogen precursors for production of dimethylether( DME) via methanol dehydration in a fixed bed reactor. The catalysts were characterized by SEM,XRD,BET and NH3-TPD. The reaction conditions were temperatures from 100 to 300 ℃ and a WHSV = 15. 9 h-1. All halogenated catalysts showhigher catalytic activities at all reaction temperatures studied. However, the halogenated zeolite catalysts prepared under ultrasonic irradiation showhigher performance for DME formation. The chlorinated zeolite catalysts show higher activity and selectivity for DME production than the respective fluorinated versions.展开更多
Chlorine disinfection of saline wastewater effluents rich in bromide and iodide forms relatively toxic brominated and iodinated disinfection byproducts(DBPs). Ultrasonication is a relatively new water treatment techno...Chlorine disinfection of saline wastewater effluents rich in bromide and iodide forms relatively toxic brominated and iodinated disinfection byproducts(DBPs). Ultrasonication is a relatively new water treatment technology, and it is less sensitive to suspended solids in wastewaters. In this study, we examined the effects of ultrasonication(in terms of reactor type and combination mode with chlorination) on the DBP formation and toxicity in chlorinated primary and secondary saline wastewater effluents. Compared with the chlorinated wastewater effluent samples without ultrasonication, ultrasonic horn pretreatment of the wastewater effluent samples reduced the total organic halogen(TOX) levels in chlorination by ~30%, but ultrasonic bath pretreatment of the wastewater samples did not significantly change the TOX levels in chlorination, which might be attributed to the higher energy utilization and decomposition extent of organic DBP precursors in the ultrasonic horn reactor. Moreover, the TOX levels in the chlorinated samples with ultrasonic horn pretreatment(USH–chlorination), simultaneous treatment(chlorination + USH) and subsequent treatment(chlorination–USH) were also significantly reduced, with the maximum TOX reductions occurring in the samples with ultrasonic horn pretreatment. A toxicity index was calculated by weighting and summing the levels of total organic chlorine, total organic bromine and total organic iodine in each treated sample. The calculated toxicity index values of the chlorinated wastewater effluent samples followed a descending rank order of “chlorination” > “chlorination + USH” > “chlorination–USH” > “USH–chlorination”, with the lowest toxicity occurring in the samples with ultrasonic horn pretreatment. Then, a developmental toxicity bioassay was conducted for each treated sample. The measured toxicity index values of the chlorinated wastewater samples followed the same descending rank order.展开更多
A thin film TiO2 in hierarchical nano-structure with high photocatalytic activities was synthesized in simple steps with ultrasonication. The crystal structure and morphology of the photocatalyst were investigated by ...A thin film TiO2 in hierarchical nano-structure with high photocatalytic activities was synthesized in simple steps with ultrasonication. The crystal structure and morphology of the photocatalyst were investigated by X-ray diffraction (XRD) and high-resolution field emission scanning electron microscope (FE-SEM). In the present work, nanostructured TiO2 was directly formed onto a Ti substrate via a solution approach. This nanostructured TiO2 photocatalyst can be reused and will not generate secondary contamination to treated water. The photocatalytic activity of the synthesized TiO2 photocatalyst was evaluated by the degradation of phenol under UVC irradiation in water and was compared with the general sol-gel derived TiO2 films as well as a commercial DP-25 TiO2 coating. It was found that the synthesized nanostructured TiO2has significantly high and stable photocatalytic activity.展开更多
Multi-walled carbon nanotubes（MWCNTs） reinforced hollow glass microspheres（HGMs）/epoxy syntactic foam was fabricated. The effects of ultrasonication on the density, compression strength, and water absorption prope...Multi-walled carbon nanotubes（MWCNTs） reinforced hollow glass microspheres（HGMs）/epoxy syntactic foam was fabricated. The effects of ultrasonication on the density, compression strength, and water absorption properties were studied. Better dispersed MWCNTs can be obtained after ultrasonication treatment, but an increasing viscosity will lead to a larger amount of voids during syntactic foam preparation especially when the content of HGMs is more than 70 vol%. The existing voids will decrease the density of epoxy syntactic foam. However, the ultrasonication does not change the compression strength much. Ultrasonication treatment will decrease the water absorption content due to the better dispersion and hydrophobic properties of MWCNTs. But a significant increase of water absorption content occurs when HGMs is more than 70 vol%, which is attributed to the higher viscosity and larger amount of voids.展开更多
Peat and peatified wood are significant carbohydrate resources in tropical rainforests. The carbohydrates of cellulose and hemicellulose are important sources of monosaccharides for both vital activities and industria...Peat and peatified wood are significant carbohydrate resources in tropical rainforests. The carbohydrates of cellulose and hemicellulose are important sources of monosaccharides for both vital activities and industrial applications, such as furan production of furfural and hydroxymethyl furfural. Hydrothermal treatment at 200°C and ultrasonic irradiation pretreatment were used to recover monosaccharides from the abovementioned resources. The monosaccharide recovery from peat was shown to be higher than that from peatified wood. The conversion to organic acids is considered to proceed rapidly because acids are always detected with monosaccharides. This conversion is outstripped by the organic acid-to-gas reaction for treatment times longer than 20 min. The monosaccharide recovery from peatified wood was improved by the ultrasonication pretreatment. It is considered that ultrasonic irradiation broke down lignin blockages, enabling water molecules to access the carbohydrates more easily in the subsequent hydrothermal treatment.展开更多
Poly[2-methoxy-5-（2＇-ethyl-hexyloxy）-1,4-phenylene vinylene]（MEH-PPV）solutions with different concen-trations were prepared in chloroform for different ultrasonication times.The ultraviolet absorption and photolu...Poly[2-methoxy-5-（2＇-ethyl-hexyloxy）-1,4-phenylene vinylene]（MEH-PPV）solutions with different concen-trations were prepared in chloroform for different ultrasonication times.The ultraviolet absorption and photoluminescence（PL）spectra of the MEH-PPV solutions were measured,and the electronic states of the polymer chains under different experimental conditions were studied.The results showed that the effects of ultrasonication on the dilute and concentrated solutions were different.After ultrasonication,the intensity of the absorption peak at 280 nm significantly decreased,relative to the absorption peak at 500 nm for both dilute and concentrated solutions,indicating that the proportion of the two excited states in the polymer chains had changed.For dilute MEH-PPV solutions,the blue-shifted absorption（at about 500 nm）and PL spectra show that ultrasonication also led to polymer chain degradation and thus shortened the effective conjugation length.For concentrated solutions,however,the peak positions of the absorption spectra remained unchanged.In addition,the effects of the solution temperatures on the optical spectra for the MEH-PPV solutions were also discussed.展开更多
A large amount of sludge is inevitably produced during sewage treatment.Ultrasonication(US)as anaerobic digestion(AD)pretreatment was implemented on different sludges and its effects on batch and semi-continuous AD pe...A large amount of sludge is inevitably produced during sewage treatment.Ultrasonication(US)as anaerobic digestion(AD)pretreatment was implemented on different sludges and its effects on batch and semi-continuous AD performance were investigated.US was ef-fective in sludge SCOD increase,size decrease,and CH_(4)production in the subsequent AD,and these effects were enhanced with an elevated specific energy input.As indicated by semi-continuous AD experiments,the mean daily CH_(4)production of US-pretreated A^(2)O-,A^(2)O-MBR-,and AO-AO-sludgewere 176.9,119.8,and 141.7 NmL/g-VSadded,whichwere 35.1%,32.1%and 78.2%higher than methane production of their respective raw sludge.The US of A^(2)O-sludge achieved preferable US effects and CH_(4)production due to its high organic con-tent andweak sludge structure stability.In response to US-pretreated sludge,amore diverse microbial community was observed in AD.The US-AD system showed negative net energy;however,it exhibited other positive effects,e.g.,lower required sludge retention time and less residual total solids for disposal.US is a feasible option prior to AD to improve anaer-obic bioconversion and CH_(4)yield although further studies are necessary to advance it in practice.展开更多
To investigate the effect of clay concentration on the structures and properties of bisphenol-A epoxy/nanoclay composites, three composites with organoclay concentrations of 2.5wt%, 5wt%, and 7.5wt% of the epoxy resin...To investigate the effect of clay concentration on the structures and properties of bisphenol-A epoxy/nanoclay composites, three composites with organoclay concentrations of 2.5wt%, 5wt%, and 7.5wt% of the epoxy resin were prepared by in-situ polymerization under mechanical stirring followed by ultrasonic treatment. The clay aggregates on micro-scale indicate the absence of fully exfoliated nanocomposites. The layer space decreases with the increase of clay concentration, which suggests that the exfoliation would be constrained if more clay is added as the ultrasonic force is exerted. The thermal decomposition temperature remains almost unchanged with the increase of clay concentration. The glass transition temperature of the composites decreases slightly with the increase of clay concentration, whereas the storage modulus increases with the increase of clay concentration.展开更多
We investigated the feasibility of sonodynamic therapy for glioma by low frequency ultrasoundwith5-aminolevulinic acid (5-ALA), a precursor of protoporphyrin IX (PpIX) in heme synthetic process. In vivo tumor model wa...We investigated the feasibility of sonodynamic therapy for glioma by low frequency ultrasoundwith5-aminolevulinic acid (5-ALA), a precursor of protoporphyrin IX (PpIX) in heme synthetic process. In vivo tumor model was made by inoculating human glioma cell line U87-MG subcutaneously in nude mice. The tumor was sonicated by 25-kHz ultrasound 4 hours following administration of 5-ALA. The tumor size decreased in 5-ALA administered (ALA(+)US(+)) mice, while increased in non-5-ALA administrated (ALA(-)US(+)) mice and non-sonicated mice (ALA(+)US(-)). The immunohistochemical analysis revealed an apoptotic change in tumor tissue of ALA(+)US(+) mice. The results showed the therapeutic effect of 25 kHz ultrasound for the glioma in 5-ALA administered tumor-bearing mice by inducing apoptotic change of tumor cells. This is a first report to elucidate the feasibility of therapeutic use of 25 kHz, relatively low frequency, ultrasound in sonodynamic therapy using 5-ALA as a sonosensitizer precursor. The utilization of this frequency will contribute to the development of sonodynamic therapy for gliomas and the spread of this technique in many hospitals that possess ultrasonic aspirators.展开更多
The decoration of CNTs surface by magnetic nanoparticles was achieved by an ultrasonication-assisted hydrothermal method（UAHM）.The effect of ultrasonication time on the crystal structure,magnetic performance,and che...The decoration of CNTs surface by magnetic nanoparticles was achieved by an ultrasonication-assisted hydrothermal method（UAHM）.The effect of ultrasonication time on the crystal structure,magnetic performance,and chemical composition of the magnetic CNT composite material was determined.X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR）,transmission electron microscopy（TEM）,and vibrating sample magnetometry were used to characterize the physical,chemical,and magnetic properties of the composites.The composites synthesized via the UAHM exhibited superparamagnetic properties.The ultrasonication time was a critical factor that affected the structure and magnetic performance of the composites.By simply controlling the ultrasonication time,the crystal phase structure of Fe oxide could be selectively modulated and the magnetic performance of the MCs could be effectively tuned.展开更多
The effects of electric field and ultrasonication on the deposition and alignment of single-walled carbon nanotubes (SWCNTs) across a 10 μm electrode gap have been studied. It was found that a frequency of ~1 MHz of ...The effects of electric field and ultrasonication on the deposition and alignment of single-walled carbon nanotubes (SWCNTs) across a 10 μm electrode gap have been studied. It was found that a frequency of ~1 MHz of the applied field yields the largest current independent of the magnitude of the voltage or the ultrasonication time of the sample. Increasing the ultrasonication time of a SWCNT solution changes the I-V characteristics of the deposited nanotubes from linear to nonlinear for all the voltages and frequencies of the applied field. Even in the absence of an electric field, SWCNTs bridged the electrode gap up to a critical sonication time which depends on the concentration of nanotubes in the solution.展开更多
Background:Cotton gin trash(CGT)is a lignocellulosic residue that can be used in the production of cellulosic ethanol.In a previous research,the sequential use of ultrasonication,liquid hot water,and ligninolytic enzy...Background:Cotton gin trash(CGT)is a lignocellulosic residue that can be used in the production of cellulosic ethanol.In a previous research,the sequential use of ultrasonication,liquid hot water,and ligninolytic enzymes was selected as pretreatment for the production of ethanol from CGT.However,an increment in the ethanol production is necessary.To accomplish that,this research evaluated the effect of pretreating CGT using alkaline ultrasonication before a liquid hot water and ligninolytic enzymes pretreatments for ethanol production.Three NaOH concentrations(5%,10%,and 15%)were employed for the alkaline ultrasonication.Additionally,this work is one of the first applications of Fourier transform infrared(FT-IR)spectrum and principal component analysis(PCA)as fast methodology to identify the differences in the biomass after different types of pretreatments.Results:The three concentrations employed for the alkaline ultrasonication pretreatment produced ethanol yields and cellulose conversions higher than the experiment without NaOH.Furthermore,15%NaOH concentration achieved twofold increment yield versus the treatment without NaOH.The FT-IR spectrum confirmed modifications in the CGT structure in the different pretreatments.PCA was helpful to determine differences between the pretreated and un-pretreated biomass and to evaluate how the CGT structure changed after each treatment.Conclusions:The combination of alkali ultrasonication hydrolysis,liquid hot water,and ligninolytic enzymes using 15%of NaOH improved 35%the ethanol yield compared with the original treatment.Additionally,we demonstrated the use of PCA to identify the modifications in the biomass structure after different types of pretreatments and conditions.展开更多
The extraction of polyphenols from Aronia melanocarpa was carried out using a combination of enzymatic and ultrasound.After single-factor and orthogonal design and experiment,the optimized polyphenol extraction condit...The extraction of polyphenols from Aronia melanocarpa was carried out using a combination of enzymatic and ultrasound.After single-factor and orthogonal design and experiment,the optimized polyphenol extraction conditions were 1%enzyme,1:40 material-to-liquid ratio,55℃,60 min ultrasonication,70%ethanol,and the final extraction amount was 88.634 mg/g,which displayed a 25.15%and 34.08%improvement compared with the single ultrasonication and enzymatic extraction methods,respectively.Significant antibacterial effects of polyphenols were shown against Staphylococcus aureus,Escherichia coli and Bacillus subtilis.Further antioxidation effects were evaluated,and the superoxide anion radical scavenging rate,hydroxyl radical scavenging rate and DPPH free radical scavenging rate reached 45.2%,83.5%and 85.4%,respectively.This combined enzymatic and ultrasonic extraction method exhibited the advantages of high extraction rate,saving solvent consumption and extraction time,but also provided a new method for the development and utilization of natural antimicrobial and antioxidant health products.展开更多
The ultrasonic technique has been demonstrated to be a promising method for the disposal of hazardous oily sludge.However,the separation of oil from the surfaces of the solid particles is still difficult due to the st...The ultrasonic technique has been demonstrated to be a promising method for the disposal of hazardous oily sludge.However,the separation of oil from the surfaces of the solid particles is still difficult due to the strong interaction between the oil and solid particle.In this study,three types of surfactants were used to assist the ultrasonic treatment of oily sludge.The oil component,surface composition,and structure of the solid particle were determined.The results showed that different surfactants had different oil removal abilities.In the three surfactant-assisted sonication systems,the oil removal rate increased during the starting reaction period and then decreased with longer sonication time.The results of four components analysis suggested that surfactant easy to be ionized in water posed a better removal effect on resins,while the amphiphilic surfactant preferred saturates,aromatics and asphaltenes.The morphology analysis indicated that particle size was shattered into smaller ones by the ultrasonic process,and the wettability of the solid surface also changed during this treatment.The characterization of the oil component and solid particle during surfactant-assisted ultrasonication treatment will help to better understand the separation of oil from oily sludge and improve the oil recovery efficiency from oily sludge.展开更多
Effective separation of residual carbon and ash is the basis for the resource utilization of coal gasification fine slag(CGFS).The conventional flotation process of CGFS has the bottlenecks of low carbon recovery and ...Effective separation of residual carbon and ash is the basis for the resource utilization of coal gasification fine slag(CGFS).The conventional flotation process of CGFS has the bottlenecks of low carbon recovery and high collector dosage.In order to address these issues,CGFS sample taken from Shaanxi,China was used as the study object in this paper.A new process of size classification-fine grain ultrasonic pretreatment flotation(SC-FGUF)was proposed and its separation effect was compared with that of wholegrain flotation(WGF)as well as size classification-fine grain flotation(SC-FGF).The mechanism of its enhanced separation effect was revealed through flotation kinetic fitting,flotation flow foam layer stability,particle size composition,surface morphology,pore structure,and surface chemical property analysis.The results showed that compared with WGF,pre-classification could reduce the collector dosage by 84.09%and the combination of pre-classification and ultrasonic pretreatment could increase the combustible recovery by 17.29%and up to 93.46%.The SC-FGUF process allows the ineffective adsorption of coarse residual carbon to collector during flotation stage to be reduced by pre-classification,and the tightly embedded state of fine CGFS particles is disrupted and surface oxidizing functional group occupancy was reduced by ultrasonic pretreatment,thus carbon and ash is easier to be separated in the flotation process.In addition,some of the residual carbon particles were broken down to smaller sizes in the ultrasonic pretreatment,which led to an increase in the stability of flotation flow foam layer and a decrease in the probability of detachment of residual carbon particles from the bubbles.Therefore,SCFGUF could increase the residual carbon recovery and reduce the flotation collector dosage,which is an innovative method for carbon-ash separation of CGFS with good application prospect.展开更多
Objectives Chilling injury is a prominent physiological disorder in longkong fruit pericarp when stored under 13℃for a prolonged period.This study aimed to investigate the effects of individual salicylic acid(SA)and ...Objectives Chilling injury is a prominent physiological disorder in longkong fruit pericarp when stored under 13℃for a prolonged period.This study aimed to investigate the effects of individual salicylic acid(SA)and ultrasonication(US)treatments and of the combination salicylic acid and ultrasonication(SA-US)on alleviating the chilling injury symptoms in longkong fruit pericarp when in prolonged cold storage.Materials and Methods SA(1 mmol/L)and US(40 kHz,10 min at 90%amplitude,350 W)were used as individual and combined(SA-US)treat-ments to control the chilling injury in longkong pericarp.The various quality measures were checked every 2 d in longkong for up to 18 d of cold storage(13℃,90%relative humidity).Results The results revealed that the control fruits treated with water exhibited severe chilling injury symptoms followed in rank order by US,SA,and SA-US cases.Treatments such as US and SA alone were more effective in controlling chilling injuries than control,while only minimal signifi-cant differences were noticed between them.On the other hand,the longkong pericarp treated with the SA-US combination had significantly increased antioxidant enzyme(superoxide dismutase and catalase)activities and decreased levels of membrane lytic(phospholipase D and lipoxygenase)enzymes and browning-inducing enzymes(phenylalanine ammonia lyase and polyphenol oxidase).Consequently,in the longkong pericarp,the chilling injury index,electrolytic leakage,respiration rate,weight loss,firmness,malondialdehyde content,changes in unsaturated and saturated fatty acid contents,and reactive oxygen species were significantly controlled by this treatment.Conclusions The present study concludes that longkong fruit treatment with a combination of US and SA is an excellent alternative for control-ling the chilling injury symptoms and extending the shelf-life.展开更多
An insecticidal protein gene isolated from Bacillus thuringiensis was transferred into maize by using ultrasonication. The fertile transgenic plants and their progeny were obtained. The Southern hybridization results ...An insecticidal protein gene isolated from Bacillus thuringiensis was transferred into maize by using ultrasonication. The fertile transgenic plants and their progeny were obtained. The Southern hybridization results indi-cated that the foreign gene had integrated into the maize genome. It has been found that the acoustic intensity and the duration of treatment are the important parameters influencing transformation efficiency by ultrasonication. The maxi-mum relative transformation frequency of 34. 1 % was achieved after 30 min of sonication at 0. 5 W/cm2 acoustic inten-sity. With appropriate parameters the ultrasonication ran make a number of micropores formed on the cell surface and minimize the treatment damage to the foreign DNA molecules, thus facilitating the DNA molecules to enter the cells.展开更多
Ultrasonication and mechanical refining pretreatments were carried out to enhance alkali swelling of bamboo fibers to improve accessibility and porosity.Cellulose-based magnetic beads were synthesized with the alkali ...Ultrasonication and mechanical refining pretreatments were carried out to enhance alkali swelling of bamboo fibers to improve accessibility and porosity.Cellulose-based magnetic beads were synthesized with the alkali swollen bamboo fibers and Fe3O4 nanoparticles.Compared to the fibers treated with alkali alone,the water retention value(WRV)increased by 33.87%for the fibers treated by sonication and alkali,and by 94.58%for those treated by mechanical refining and alkali.The increased WRV was attributed to disruption of the crystalline region of fibers in the combined treatments which resulted in decreased crystallinity and degree of polymerization of cellulose.Furthermore,compared with the control sample which was treated by alkali alone,the specific surface area and pore volume of the samples treated by the combined processes increased markedly,which favored the adsorption of Fe3O4 nanoparticles in the synthesis of functional magnetic cellulose beads for the applications of protein immobilization,drug carrier and wastewater treatment.展开更多
基金supported by Sichuan Environmental Protection Industry Group Co.,Ltd.,China(No.2021-CNSW-A01).
文摘Recently,using anaerobic hydrolysis of waste activated sludge (WAS) to recover volatile fatty acids (VFAs) as carbon sources for denitrification has been widely studied,and the key is to solve the problem of improving the solubility and bioavailability of WAS organic matter.Considering the energy consumption and chemical cost,this paper used low-dose nanozero-valent iron (NZVI) coupled with low-intensity ultrasonication (US) to pretreat WAS,and explored the effects of different treatment sequences on the fragmentation of WAS flocs particles,the dissolution of organic matter,and the subsequent biofermentation conversion process.The results showed low-dose NZVI synchronized with low-intensity US (NZVIUS)worked best for WAS anaerobic fermentation.Compared with 2062 mg/L in control group,soluble chemical oxygen demand (SCOD) after NZVIUS treatment reached up to 2786 mg/L during the fermentation cycle,and the initial release rate of SCOD increased by 69%.The VFAs production was elevated from 1522 to 1940 mg COD/L.NZVIUS pretreatment promoted the solubilization of attached organic matter,manifested by the fragmentation of WAS flocs and cell lysis.At the same time,proteins and carbohydrates in the extracellular polymeric substances (EPS) had different types of migration and transformation,and transfer of EPS can contribute 35.6% to SCOD.Moreover,adding NZVI promoted PO_(4)^(3-)-P recovery in the fermentation supernatant by 22.3% more than in day 4 control.This study demonstrated that the NZVIUS pretreatment method can effectively improve the production of VFAs by WAS anaerobic fermentation,meeting the practical needs of wastewater plants.
基金Supported by Scientific and Technological Project in Shanxi Province(021034)Scientific Research Project of Shanxi Academy of Agri-cultural Sciences (YGX-01)~~
文摘[Objective] This research aimed to explore the method to increase conversion rate of pollen-tub pathway in Chinese cabbage.[Method] Chinese cabbage varieties Yuqing and No.03 were used as materials for the selection of germination buffer and parameters for ultrasonication.[Result] The optimal buffer for pollen germination of Chinese cabbage was 200 g/L sucrose ＋ 100 mg/L boric acid ＋ 200 mg/L calcium nitrate,the preferred ultrasonic processing power was 150 W,processing time was 5 s,interval time was 5 s and processing frequency was 8.Three T1-generation plants were obtained through selection with 200 mg/L kanamycin.[Conclusion] This research laid foundation for the further genetic transformation of Chinese cabbage.
文摘The chlorinated and fluorinated zeolite catalysts were prepared by the impregnation of zeolites( H-ZSM-5,H-MOR or H-Y) using two halogen precursors( ammonium chloride and ammonium fluoride) in this study. The influence of ultrasonic irradiation was evaluated for optimizing both halogen precursors for production of dimethylether( DME) via methanol dehydration in a fixed bed reactor. The catalysts were characterized by SEM,XRD,BET and NH3-TPD. The reaction conditions were temperatures from 100 to 300 ℃ and a WHSV = 15. 9 h-1. All halogenated catalysts showhigher catalytic activities at all reaction temperatures studied. However, the halogenated zeolite catalysts prepared under ultrasonic irradiation showhigher performance for DME formation. The chlorinated zeolite catalysts show higher activity and selectivity for DME production than the respective fluorinated versions.
基金supported by the Research Grants Council of Hong Kong, China (Nos. 16212518 , 16210221 , T21-711/16R , and T21-705/20-N)the Guangdong Basic and Applied Basic Research of the Joint Regional Fund, Guangdong, China (No. 2019A1515110569)。
文摘Chlorine disinfection of saline wastewater effluents rich in bromide and iodide forms relatively toxic brominated and iodinated disinfection byproducts(DBPs). Ultrasonication is a relatively new water treatment technology, and it is less sensitive to suspended solids in wastewaters. In this study, we examined the effects of ultrasonication(in terms of reactor type and combination mode with chlorination) on the DBP formation and toxicity in chlorinated primary and secondary saline wastewater effluents. Compared with the chlorinated wastewater effluent samples without ultrasonication, ultrasonic horn pretreatment of the wastewater effluent samples reduced the total organic halogen(TOX) levels in chlorination by ~30%, but ultrasonic bath pretreatment of the wastewater samples did not significantly change the TOX levels in chlorination, which might be attributed to the higher energy utilization and decomposition extent of organic DBP precursors in the ultrasonic horn reactor. Moreover, the TOX levels in the chlorinated samples with ultrasonic horn pretreatment(USH–chlorination), simultaneous treatment(chlorination + USH) and subsequent treatment(chlorination–USH) were also significantly reduced, with the maximum TOX reductions occurring in the samples with ultrasonic horn pretreatment. A toxicity index was calculated by weighting and summing the levels of total organic chlorine, total organic bromine and total organic iodine in each treated sample. The calculated toxicity index values of the chlorinated wastewater effluent samples followed a descending rank order of “chlorination” > “chlorination + USH” > “chlorination–USH” > “USH–chlorination”, with the lowest toxicity occurring in the samples with ultrasonic horn pretreatment. Then, a developmental toxicity bioassay was conducted for each treated sample. The measured toxicity index values of the chlorinated wastewater samples followed the same descending rank order.
文摘A thin film TiO2 in hierarchical nano-structure with high photocatalytic activities was synthesized in simple steps with ultrasonication. The crystal structure and morphology of the photocatalyst were investigated by X-ray diffraction (XRD) and high-resolution field emission scanning electron microscope (FE-SEM). In the present work, nanostructured TiO2 was directly formed onto a Ti substrate via a solution approach. This nanostructured TiO2 photocatalyst can be reused and will not generate secondary contamination to treated water. The photocatalytic activity of the synthesized TiO2 photocatalyst was evaluated by the degradation of phenol under UVC irradiation in water and was compared with the general sol-gel derived TiO2 films as well as a commercial DP-25 TiO2 coating. It was found that the synthesized nanostructured TiO2has significantly high and stable photocatalytic activity.
基金Funded by the National Natural Science Foundation of China(Nos.51301029 and 51375071)the Fundamental Research Funds for the Central Universities(No.DUT17RC(3)012)
文摘Multi-walled carbon nanotubes（MWCNTs） reinforced hollow glass microspheres（HGMs）/epoxy syntactic foam was fabricated. The effects of ultrasonication on the density, compression strength, and water absorption properties were studied. Better dispersed MWCNTs can be obtained after ultrasonication treatment, but an increasing viscosity will lead to a larger amount of voids during syntactic foam preparation especially when the content of HGMs is more than 70 vol%. The existing voids will decrease the density of epoxy syntactic foam. However, the ultrasonication does not change the compression strength much. Ultrasonication treatment will decrease the water absorption content due to the better dispersion and hydrophobic properties of MWCNTs. But a significant increase of water absorption content occurs when HGMs is more than 70 vol%, which is attributed to the higher viscosity and larger amount of voids.
文摘Peat and peatified wood are significant carbohydrate resources in tropical rainforests. The carbohydrates of cellulose and hemicellulose are important sources of monosaccharides for both vital activities and industrial applications, such as furan production of furfural and hydroxymethyl furfural. Hydrothermal treatment at 200°C and ultrasonic irradiation pretreatment were used to recover monosaccharides from the abovementioned resources. The monosaccharide recovery from peat was shown to be higher than that from peatified wood. The conversion to organic acids is considered to proceed rapidly because acids are always detected with monosaccharides. This conversion is outstripped by the organic acid-to-gas reaction for treatment times longer than 20 min. The monosaccharide recovery from peatified wood was improved by the ultrasonication pretreatment. It is considered that ultrasonic irradiation broke down lignin blockages, enabling water molecules to access the carbohydrates more easily in the subsequent hydrothermal treatment.
基金the Shanghai Leading Academic Discipline Project(No.B113)the Program for New Century ExcellentTalents(NCET)in University of China(No.NCET-04-0355).
文摘Poly[2-methoxy-5-（2＇-ethyl-hexyloxy）-1,4-phenylene vinylene]（MEH-PPV）solutions with different concen-trations were prepared in chloroform for different ultrasonication times.The ultraviolet absorption and photoluminescence（PL）spectra of the MEH-PPV solutions were measured,and the electronic states of the polymer chains under different experimental conditions were studied.The results showed that the effects of ultrasonication on the dilute and concentrated solutions were different.After ultrasonication,the intensity of the absorption peak at 280 nm significantly decreased,relative to the absorption peak at 500 nm for both dilute and concentrated solutions,indicating that the proportion of the two excited states in the polymer chains had changed.For dilute MEH-PPV solutions,the blue-shifted absorption（at about 500 nm）and PL spectra show that ultrasonication also led to polymer chain degradation and thus shortened the effective conjugation length.For concentrated solutions,however,the peak positions of the absorption spectra remained unchanged.In addition,the effects of the solution temperatures on the optical spectra for the MEH-PPV solutions were also discussed.
基金supported by the National Natural Science Foundation of China(Nos.52192683,51925807,and 52221004)the National Science Fund for Distinguished Young Scholars of China(No.52125003)the Key Research Program of Frontier Sciences,CAS(No.ZDBS-LY-DQC014).
文摘A large amount of sludge is inevitably produced during sewage treatment.Ultrasonication(US)as anaerobic digestion(AD)pretreatment was implemented on different sludges and its effects on batch and semi-continuous AD performance were investigated.US was ef-fective in sludge SCOD increase,size decrease,and CH_(4)production in the subsequent AD,and these effects were enhanced with an elevated specific energy input.As indicated by semi-continuous AD experiments,the mean daily CH_(4)production of US-pretreated A^(2)O-,A^(2)O-MBR-,and AO-AO-sludgewere 176.9,119.8,and 141.7 NmL/g-VSadded,whichwere 35.1%,32.1%and 78.2%higher than methane production of their respective raw sludge.The US of A^(2)O-sludge achieved preferable US effects and CH_(4)production due to its high organic con-tent andweak sludge structure stability.In response to US-pretreated sludge,amore diverse microbial community was observed in AD.The US-AD system showed negative net energy;however,it exhibited other positive effects,e.g.,lower required sludge retention time and less residual total solids for disposal.US is a feasible option prior to AD to improve anaer-obic bioconversion and CH_(4)yield although further studies are necessary to advance it in practice.
文摘To investigate the effect of clay concentration on the structures and properties of bisphenol-A epoxy/nanoclay composites, three composites with organoclay concentrations of 2.5wt%, 5wt%, and 7.5wt% of the epoxy resin were prepared by in-situ polymerization under mechanical stirring followed by ultrasonic treatment. The clay aggregates on micro-scale indicate the absence of fully exfoliated nanocomposites. The layer space decreases with the increase of clay concentration, which suggests that the exfoliation would be constrained if more clay is added as the ultrasonic force is exerted. The thermal decomposition temperature remains almost unchanged with the increase of clay concentration. The glass transition temperature of the composites decreases slightly with the increase of clay concentration, whereas the storage modulus increases with the increase of clay concentration.
文摘We investigated the feasibility of sonodynamic therapy for glioma by low frequency ultrasoundwith5-aminolevulinic acid (5-ALA), a precursor of protoporphyrin IX (PpIX) in heme synthetic process. In vivo tumor model was made by inoculating human glioma cell line U87-MG subcutaneously in nude mice. The tumor was sonicated by 25-kHz ultrasound 4 hours following administration of 5-ALA. The tumor size decreased in 5-ALA administered (ALA(+)US(+)) mice, while increased in non-5-ALA administrated (ALA(-)US(+)) mice and non-sonicated mice (ALA(+)US(-)). The immunohistochemical analysis revealed an apoptotic change in tumor tissue of ALA(+)US(+) mice. The results showed the therapeutic effect of 25 kHz ultrasound for the glioma in 5-ALA administered tumor-bearing mice by inducing apoptotic change of tumor cells. This is a first report to elucidate the feasibility of therapeutic use of 25 kHz, relatively low frequency, ultrasound in sonodynamic therapy using 5-ALA as a sonosensitizer precursor. The utilization of this frequency will contribute to the development of sonodynamic therapy for gliomas and the spread of this technique in many hospitals that possess ultrasonic aspirators.
基金supported by The National Natural Science Foundation of China (Nos. 21406039, 21506174)the Project of Postgraduate Degree Construction, Southwest University for Nationalities (No. 2015XWD-S0703)
文摘The decoration of CNTs surface by magnetic nanoparticles was achieved by an ultrasonication-assisted hydrothermal method（UAHM）.The effect of ultrasonication time on the crystal structure,magnetic performance,and chemical composition of the magnetic CNT composite material was determined.X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR）,transmission electron microscopy（TEM）,and vibrating sample magnetometry were used to characterize the physical,chemical,and magnetic properties of the composites.The composites synthesized via the UAHM exhibited superparamagnetic properties.The ultrasonication time was a critical factor that affected the structure and magnetic performance of the composites.By simply controlling the ultrasonication time,the crystal phase structure of Fe oxide could be selectively modulated and the magnetic performance of the MCs could be effectively tuned.
文摘The effects of electric field and ultrasonication on the deposition and alignment of single-walled carbon nanotubes (SWCNTs) across a 10 μm electrode gap have been studied. It was found that a frequency of ~1 MHz of the applied field yields the largest current independent of the magnitude of the voltage or the ultrasonication time of the sample. Increasing the ultrasonication time of a SWCNT solution changes the I-V characteristics of the deposited nanotubes from linear to nonlinear for all the voltages and frequencies of the applied field. Even in the absence of an electric field, SWCNTs bridged the electrode gap up to a critical sonication time which depends on the concentration of nanotubes in the solution.
文摘Background:Cotton gin trash(CGT)is a lignocellulosic residue that can be used in the production of cellulosic ethanol.In a previous research,the sequential use of ultrasonication,liquid hot water,and ligninolytic enzymes was selected as pretreatment for the production of ethanol from CGT.However,an increment in the ethanol production is necessary.To accomplish that,this research evaluated the effect of pretreating CGT using alkaline ultrasonication before a liquid hot water and ligninolytic enzymes pretreatments for ethanol production.Three NaOH concentrations(5%,10%,and 15%)were employed for the alkaline ultrasonication.Additionally,this work is one of the first applications of Fourier transform infrared(FT-IR)spectrum and principal component analysis(PCA)as fast methodology to identify the differences in the biomass after different types of pretreatments.Results:The three concentrations employed for the alkaline ultrasonication pretreatment produced ethanol yields and cellulose conversions higher than the experiment without NaOH.Furthermore,15%NaOH concentration achieved twofold increment yield versus the treatment without NaOH.The FT-IR spectrum confirmed modifications in the CGT structure in the different pretreatments.PCA was helpful to determine differences between the pretreated and un-pretreated biomass and to evaluate how the CGT structure changed after each treatment.Conclusions:The combination of alkali ultrasonication hydrolysis,liquid hot water,and ligninolytic enzymes using 15%of NaOH improved 35%the ethanol yield compared with the original treatment.Additionally,we demonstrated the use of PCA to identify the modifications in the biomass structure after different types of pretreatments and conditions.
文摘The extraction of polyphenols from Aronia melanocarpa was carried out using a combination of enzymatic and ultrasound.After single-factor and orthogonal design and experiment,the optimized polyphenol extraction conditions were 1%enzyme,1:40 material-to-liquid ratio,55℃,60 min ultrasonication,70%ethanol,and the final extraction amount was 88.634 mg/g,which displayed a 25.15%and 34.08%improvement compared with the single ultrasonication and enzymatic extraction methods,respectively.Significant antibacterial effects of polyphenols were shown against Staphylococcus aureus,Escherichia coli and Bacillus subtilis.Further antioxidation effects were evaluated,and the superoxide anion radical scavenging rate,hydroxyl radical scavenging rate and DPPH free radical scavenging rate reached 45.2%,83.5%and 85.4%,respectively.This combined enzymatic and ultrasonic extraction method exhibited the advantages of high extraction rate,saving solvent consumption and extraction time,but also provided a new method for the development and utilization of natural antimicrobial and antioxidant health products.
基金financial support from the National Natural Science Foundation of China(Nos.41977142 and 41807133)the special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(No.18K05ESPCT)。
文摘The ultrasonic technique has been demonstrated to be a promising method for the disposal of hazardous oily sludge.However,the separation of oil from the surfaces of the solid particles is still difficult due to the strong interaction between the oil and solid particle.In this study,three types of surfactants were used to assist the ultrasonic treatment of oily sludge.The oil component,surface composition,and structure of the solid particle were determined.The results showed that different surfactants had different oil removal abilities.In the three surfactant-assisted sonication systems,the oil removal rate increased during the starting reaction period and then decreased with longer sonication time.The results of four components analysis suggested that surfactant easy to be ionized in water posed a better removal effect on resins,while the amphiphilic surfactant preferred saturates,aromatics and asphaltenes.The morphology analysis indicated that particle size was shattered into smaller ones by the ultrasonic process,and the wettability of the solid surface also changed during this treatment.The characterization of the oil component and solid particle during surfactant-assisted ultrasonication treatment will help to better understand the separation of oil from oily sludge and improve the oil recovery efficiency from oily sludge.
基金supported by the National Natural Science Foundation of China(No.52374279)the Natural Science Foundation of Shaanxi Province(No.2023-YBGY-055).
文摘Effective separation of residual carbon and ash is the basis for the resource utilization of coal gasification fine slag(CGFS).The conventional flotation process of CGFS has the bottlenecks of low carbon recovery and high collector dosage.In order to address these issues,CGFS sample taken from Shaanxi,China was used as the study object in this paper.A new process of size classification-fine grain ultrasonic pretreatment flotation(SC-FGUF)was proposed and its separation effect was compared with that of wholegrain flotation(WGF)as well as size classification-fine grain flotation(SC-FGF).The mechanism of its enhanced separation effect was revealed through flotation kinetic fitting,flotation flow foam layer stability,particle size composition,surface morphology,pore structure,and surface chemical property analysis.The results showed that compared with WGF,pre-classification could reduce the collector dosage by 84.09%and the combination of pre-classification and ultrasonic pretreatment could increase the combustible recovery by 17.29%and up to 93.46%.The SC-FGUF process allows the ineffective adsorption of coarse residual carbon to collector during flotation stage to be reduced by pre-classification,and the tightly embedded state of fine CGFS particles is disrupted and surface oxidizing functional group occupancy was reduced by ultrasonic pretreatment,thus carbon and ash is easier to be separated in the flotation process.In addition,some of the residual carbon particles were broken down to smaller sizes in the ultrasonic pretreatment,which led to an increase in the stability of flotation flow foam layer and a decrease in the probability of detachment of residual carbon particles from the bubbles.Therefore,SCFGUF could increase the residual carbon recovery and reduce the flotation collector dosage,which is an innovative method for carbon-ash separation of CGFS with good application prospect.
文摘Objectives Chilling injury is a prominent physiological disorder in longkong fruit pericarp when stored under 13℃for a prolonged period.This study aimed to investigate the effects of individual salicylic acid(SA)and ultrasonication(US)treatments and of the combination salicylic acid and ultrasonication(SA-US)on alleviating the chilling injury symptoms in longkong fruit pericarp when in prolonged cold storage.Materials and Methods SA(1 mmol/L)and US(40 kHz,10 min at 90%amplitude,350 W)were used as individual and combined(SA-US)treat-ments to control the chilling injury in longkong pericarp.The various quality measures were checked every 2 d in longkong for up to 18 d of cold storage(13℃,90%relative humidity).Results The results revealed that the control fruits treated with water exhibited severe chilling injury symptoms followed in rank order by US,SA,and SA-US cases.Treatments such as US and SA alone were more effective in controlling chilling injuries than control,while only minimal signifi-cant differences were noticed between them.On the other hand,the longkong pericarp treated with the SA-US combination had significantly increased antioxidant enzyme(superoxide dismutase and catalase)activities and decreased levels of membrane lytic(phospholipase D and lipoxygenase)enzymes and browning-inducing enzymes(phenylalanine ammonia lyase and polyphenol oxidase).Consequently,in the longkong pericarp,the chilling injury index,electrolytic leakage,respiration rate,weight loss,firmness,malondialdehyde content,changes in unsaturated and saturated fatty acid contents,and reactive oxygen species were significantly controlled by this treatment.Conclusions The present study concludes that longkong fruit treatment with a combination of US and SA is an excellent alternative for control-ling the chilling injury symptoms and extending the shelf-life.
基金Project supported by "863" State High Technology Development Program.
文摘An insecticidal protein gene isolated from Bacillus thuringiensis was transferred into maize by using ultrasonication. The fertile transgenic plants and their progeny were obtained. The Southern hybridization results indi-cated that the foreign gene had integrated into the maize genome. It has been found that the acoustic intensity and the duration of treatment are the important parameters influencing transformation efficiency by ultrasonication. The maxi-mum relative transformation frequency of 34. 1 % was achieved after 30 min of sonication at 0. 5 W/cm2 acoustic inten-sity. With appropriate parameters the ultrasonication ran make a number of micropores formed on the cell surface and minimize the treatment damage to the foreign DNA molecules, thus facilitating the DNA molecules to enter the cells.
基金the Central Non-profit Research Institution of CAF(CAFYBB2017ZX003-08).
文摘Ultrasonication and mechanical refining pretreatments were carried out to enhance alkali swelling of bamboo fibers to improve accessibility and porosity.Cellulose-based magnetic beads were synthesized with the alkali swollen bamboo fibers and Fe3O4 nanoparticles.Compared to the fibers treated with alkali alone,the water retention value(WRV)increased by 33.87%for the fibers treated by sonication and alkali,and by 94.58%for those treated by mechanical refining and alkali.The increased WRV was attributed to disruption of the crystalline region of fibers in the combined treatments which resulted in decreased crystallinity and degree of polymerization of cellulose.Furthermore,compared with the control sample which was treated by alkali alone,the specific surface area and pore volume of the samples treated by the combined processes increased markedly,which favored the adsorption of Fe3O4 nanoparticles in the synthesis of functional magnetic cellulose beads for the applications of protein immobilization,drug carrier and wastewater treatment.
