In this study,we analyzed the characteristics of three-dimensional excitation-emission matrix spectra(EEMs)of 150 samples from five industrial wastewater types and domestic sewage to track water pollution sources effe...In this study,we analyzed the characteristics of three-dimensional excitation-emission matrix spectra(EEMs)of 150 samples from five industrial wastewater types and domestic sewage to track water pollution sources effectively.We then developed a recognition model for wastewater EEMs by establishing a feature dataset containing fluorescence peak values and parameters derived from EEMs,integrated with machine learning techniques.This model enables the rapid and precise identification of pollution sources.Our findings suggest that although the EEMs of the sixwastewater categories are distinct,visual differentiation is challenging.This was confirmed by cosine similarity assessments,showing some samples with low within-group(<0.8)and high between-group(>0.95)similarities.Despite significant variations in EEMs features acrosswastewater categories,identifying specific pollutants remains difficult,especially for pulp mills and leather effluents.Among the tested classification algorithms,Support Vector Machine(SVM)achieved the highest performance with91.7%accuracy,94%precision,91%recall,and 92%F_(1)-score,outperforming K-Nearest Neighbors and Partial Least Squares Discriminant Analysis.The SVM significantly improved identification accuracy for pulpmill and leather processing wastewaters compared to other models.To enhance identification accuracy,further exploration of EEMs features and expanding the training dataset are recommended.Combining EEMs features with machine learning presents a promising method for improvingwater pollution supervision and source tracing in environmental management practices.展开更多
Adsorbable organic halogens（AOX） are a general indicator for the total amount of compounds containing organically bonded halogens. AOX concentrations and components were investigated along the wastewater treatment p...Adsorbable organic halogens（AOX） are a general indicator for the total amount of compounds containing organically bonded halogens. AOX concentrations and components were investigated along the wastewater treatment process in four large-scale pharmaceutical factories of China, and genotoxicity based on the SOS/umu test was also evaluated. The results showed that AOX concentrations in wastewater of four factories ranged from 4.6 to 619.4 mg/L, which were high but greatly different owing to differences in the raw materials and products. The wastewater treatment process removed 50.0%–89.9% of AOX, leaving 1.3–302.5 mg/L AOX in the effluents. Genotoxicity levels ranged between 2.1 and 68.0 μg 4-NQO/L in the raw wastewater and decreased to 1.2–41.2 μg 4-NQO/L in the effluents of the wastewater treatment plants（WWTPs）. One of the main products of factory I, ciprofloxacin, was identified as the predominant contributor to its genotoxicity. However, for the other three factories, no significant relationship was observed between genotoxicity and detected AOX compounds.展开更多
The bacterial strain Paracoccus denitrificans W12, which could utilize pyridine as its sole source of carbon and nitrogen, was added into a membrane bioreactor （MBR） to enhance the treatment of a pharmaceutical wast...The bacterial strain Paracoccus denitrificans W12, which could utilize pyridine as its sole source of carbon and nitrogen, was added into a membrane bioreactor （MBR） to enhance the treatment of a pharmaceutical wastewater. The treatment efliciencies investigated showed that the removal of chemical oxygen demand, total nitrogen, and total phosphorus were similar between bioaugmented and non-bioaugmented MBRs, however, significant removal of pyridine was obtained in the bioaugmented reactor. When the hydraulic retention time was 60 hr and the influent concentration of pyridine was 250-500 mg/L, the mean effluent concentration of pyridine without adding W12 was 57.2 mg/L, while the pyridine was degraded to an average of 10.2 mg/L with addition of W12. The bacterial community structure of activated sludge during the bioaugmented treatment was analyzed using polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE）. The results showed that the W12 inoculum reversed the decline of microbial community diversity, however, the similarity between bacterial community structure of the original sludge and that of the sludge after bioaugmentation decreased steadily during the wastewater treatment. Sequencing of the DNA recovered from DGGE gel indicated that sp., Sphingobium sp., Comamonas sp., and Hyphomicrobium sp. were the dominant organisms in time sequence in the bacterial community in the bioaugmented MBR. This implied that the bioaugmentation was affected by the adjustment of whole bacterial community structure in the inhospitable environment, rather than being due solely to the degradation performance of the bacterium added.展开更多
The dynamic change of microbial community during sludge acclimation from aerobic to anaerobic in a MBR for coking wastewater treatment was revealed by Illumina Miseq sequencing in this study. The diversity of both Bac...The dynamic change of microbial community during sludge acclimation from aerobic to anaerobic in a MBR for coking wastewater treatment was revealed by Illumina Miseq sequencing in this study. The diversity of both Bacteria and Archaea showed an increase–decrease trajectory during acclimation, and exhibited the highest at the domestication interim. Ignavibacteria changed from a tiny minority（less than 1%） to the dominant bacterial group（54.0%） along with acclimation. The relative abundance of Betaproteobacteria kept relatively steady, as in this class some species increased coupled with some other species decreased during acclimation. The dominant Archaea shifted from Halobacteria in initial aerobic sludge to Methanobacteria in the acclimated anaerobic sludge. The dominant bacterial and archaeal groups in different acclimation stages were indigenous microorganisms in the initial sludge, though some of them were very rare. This study supported that the species in＂rare biosphere＂ might eventually become dominant in response to environmental change.展开更多
A recombinant human androgen receptor yeast assay was applied to investigate the occurrence of antiandrogens as well as the mechanism for their removal during gray wastewater and coking wastewater treatment. The membr...A recombinant human androgen receptor yeast assay was applied to investigate the occurrence of antiandrogens as well as the mechanism for their removal during gray wastewater and coking wastewater treatment. The membrane reactor（MBR） system for gray wastewater treatment could remove 88.0% of antiandrogenic activity exerted by weakly polar extracts and 97.3% of that by moderately strong polar extracts, but only 32.5%of that contributed by strong polar extracts. Biodegradation by microorganisms in the MBR contributed to 95.9% of the total removal. After the treatment, the concentration of antiandrogenic activity in the effluent was still 1.05 μg flutamide equivalence（FEQ）/L, 36.2%of which was due to strong polar extracts. In the anaerobic reactor, anoxic reactor, and membrane reactor system for coking wastewater treatment, the antiandrogenic activity of raw coking wastewater was 78.6 mg FEQ/L, and the effluent of the treatment system had only 0.34 mg FEQ/L. The antiandrogenic activity mainly existed in the medium strong polar and strong polar extracts. Biodegradation by microorganisms contributed to at least 89.2%of the total antiandrogenic activity removal in the system. Biodegradation was the main removal mechanism of antiandrogenic activity in both the wastewater treatment systems.展开更多
Diisopropylthiourea（DPT）, an intermediate of a widely used cephalosporin, has been found to be one of the most refractory components in cephalosporin synthesis wastewater.This compound cannot be completely removed b...Diisopropylthiourea（DPT）, an intermediate of a widely used cephalosporin, has been found to be one of the most refractory components in cephalosporin synthesis wastewater.This compound cannot be completely removed by conventional biological processes due to its antimicrobial property. Ionizing radiation has been applied in the decomposition of refractory pollutants in recent years and has proved effective. Therefore, the decomposition of DPT by γ-irradiation was studied. The compound was irradiated at the dose of 150–2000 Gy before a change of concentration and UV absorption of the solutions was detected.Furthermore, the decomposition kinetics and radiation yield（G-value） of DPT was investigated. The results of radiation experiments on DPT-containing aqueous showed that the DPT can be effectively degraded by γ-radiation. DPT concentration decreased with increasing absorbed doses. G-values of radiolytic decomposition for DPT（20 mg/L） were 1.04 and 0.47 for absorbed doses of 150 and 2000 Gy, respectively. The initial concentration and p H of the solutions affected the degradation. As the concentration of substrate increased,the decomposition was reduced. The decrease of removal rate and radiation efficacy under alkaline condition suggested that lower p H values benefit the γ-induced degradation. UV absorption from 190 to 250 nm decreased after radiation while that from 250 to 300 nm increased, indicating the formation of by-products.展开更多
Ozonation and ionizing radiation are both advanced oxidation processes（AOPs） without chemical addition and secondary pollution. Also, the two processes＇ efficiency is determined by different p H conditions, which c...Ozonation and ionizing radiation are both advanced oxidation processes（AOPs） without chemical addition and secondary pollution. Also, the two processes＇ efficiency is determined by different p H conditions, which creates more possibilities for their combination. Importantly,the combined process of ozonation and ionizing radiation could be suitable for treating wastewaters with extreme p H values, i.e., textile wastewater. To find synergistic effects, the combined process of ozonation and ionizing radiation mineralization was investigated for degradation of polyvinyl alcohol（PVA） at different p H levels. A synergistic effect was found at initial p H in the range 3.0–9.4. When the initial p H was 3.0, the combined process of ozonation and ionizing radiation gave a PVA mineralization degree of 17%. This was 2.7 times the sum achieved by the two individual processes, and factors of 2.1 and 1.7 were achieved at initial p H of7.0 and 9.4, respectively. The combined process of ozonation and ionizing radiation was demonstrated to be a feasible strategy for treatment of PVA-containing wastewater.展开更多
Recently, water treatment by ionizing radiation has gained increasing attention as a powerful technology for the destruction of refractory pollutants. 2-Mercaptobenzothiazole（MBT） is known as a widespread, toxic and...Recently, water treatment by ionizing radiation has gained increasing attention as a powerful technology for the destruction of refractory pollutants. 2-Mercaptobenzothiazole（MBT） is known as a widespread, toxic and poorly biodegradable pollutant. This paper studied the gamma irradiation of aqueous solutions of MBT. Moreover, the effect of the addition of persulfate（S2O82-） on the radiolytic destruction of MBT was investigated. The main transformation products of the studied compound were detected and the sequence of occurrence of the products was described. The change of biodegradability of MBT solution was also observed. The main results obtained in this study indicated that gamma radiation was effective for removing MBT in aqueous solution. Persulfate addition, which induced the formation of reactive sulfate radicals（SO4-U）, greatly enhanced the degradation of MBT. Benzothiazole was identified as the first radiation product, followed by 2-hydroxybenzothiazole. Decomposition of MBT started with the oxidation of –SH groups to sulfate ions. Possible pathways for MBT decomposition by gamma irradiation were proposed. The BOD/COD ratios of MBT samples were increased after radiation,indicating the improvement of biodegradability and reduction of toxicity.展开更多
In this study, a lab-scale biological anaerobic/anaerobic/anoxic/membrane bioreactor （A3-MBR） was designed to treat wastewater from the ethanol fermentation of food waste, a promising way for the disposal of food wa...In this study, a lab-scale biological anaerobic/anaerobic/anoxic/membrane bioreactor （A3-MBR） was designed to treat wastewater from the ethanol fermentation of food waste, a promising way for the disposal of food waste and reclamation of resources. The 454 pyrosequencing technique was used to investigate the composition of the microbial community in the treatment system. The system yielded a stable effluent concentration of chemical oxygen demand （202 ± 23 mg/L）, total nitrogen （62.1 ± 7.1 mg/L）, ammonia （0.3 ±0.13 mg/L） and total phosphorus （8.3 ± 0.9 rag/L）, and the reactors played different roles in specific pollutant removal. The exploration of the microbial community in the system revealed that： （1） the microbial diversity of anaerobic reactors A1 and A2, in which organic pollutants were massively degraded, was much higher than that in anoxic A3 and aerobic MBR; （2） although the community composition in each reactor was quite different, bacteria assigned to the classes Clostridia, Bacteroidia, and Synergistia were important and common microorganisms for organic pollutant degradation in the anaerobic units, and bacteria from Alphaproteobacteria and Betaproteobacteria were the dominant microbial population in A3 and MBR; （3） the taxon identification indicated that Arcobacter in the anaerobic reactors and Thauera in the anoxic reactor were two representative genera in the biological process. Our results proved that the biological A3-MBR process is an alternative technique for treating wastewater from food waste.展开更多
Anthropogenic activities usually contaminate water environments, and have led to the eutrophication of many estuaries and shifts in microbial communities. In this study, the temporal and spatial changes of the microbi...Anthropogenic activities usually contaminate water environments, and have led to the eutrophication of many estuaries and shifts in microbial communities. In this study, the temporal and spatial changes of the microbial community in an industrial effluent receiving area in Hangzhou Bay were investigated by 454 pyrosequencing. The bacterial community showed higher richness and biodiversity than the archaeal community in all sediments. Proteobacteria dominated in the bacterial communities of all the samples; MarineGroupⅠand Methanomicrobia were the two dominant archaeal classes in the effluent receiving area. PCoA and AMOVA revealed strong seasonal but minor spatial changes in both bacterial and archaeal communities in the sediments. The seasonal changes of the bacterial community were less significant than those of the archaeal community, which mainly consisted of fluctuations in abundance of a large proportion of longstanding species rather than the appearance and disappearance of major archaeal species. Temperature was found to positively correlate with the dominant bacteria, Betaproteobacteria, and negatively correlate with the dominant archaea,MarineGroupⅠ; and might be the primary driving force for the seasonal variation of the microbial community.展开更多
A biofilm membrane bioreactor （BF-MBR） and a conventional membrane bioreactor （MBR） were parallelly operated for treating digested piggery wastewater. The removal performance of COD, TN, NH4＋-N, TP as well as ant...A biofilm membrane bioreactor （BF-MBR） and a conventional membrane bioreactor （MBR） were parallelly operated for treating digested piggery wastewater. The removal performance of COD, TN, NH4＋-N, TP as well as antibiotics were simultaneously studied when the hydraulic retention time （HRT） was gradually shortened from 9 d to 1 d and when the ratio ofinfluent COD to TN was changed. The results showed that the effluent quality in both reactors was poor and unstable at an influent COD/ TN ratio of 1.0±0.2. The effluent quality was signifcantly improved as the influent COD/TN ratio was increased to 2.3±0.5. The averaged removal rates of COD, NH4＋-N, TN and TP were 92.1%, 97.1%, 35.6% and 54.2%, respectively, in the BF-MBR, significantly higher than the corresponding values of 91.7%, 90.9%, 17.4% and 31.9% in the MBR. Analysis of 11 typical veterinary antibiotics （from the tetracycline, sulfonamide, quinolone, and macrolide families） revealed that the BF-MBR removed more antibiotics than the MBR. Although the antibiotics removal decreased with a shortened HRT, high antibiotics removals of 86.8%, 80.2% and 45.3% were observed in the BF-MBR at HRT of 5~4 d, 3-2 d and 1 d, respectively, while the corresponding values were only 83.8%, 57.0% and 25.5% in the MBR. Moreover, the BF-MBR showed a 15% higher retention rate of antibiotics and consumed 40% less alkalinity than the MBR. Results above suggest that the BF-MBR was more suitable for digested piggery wastewater treatment.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
An intermittently aerated sequencing batch reactor （IASBR） and a traditional sequencing batch reactor （SBR） were parallelly constructed to treat digested piggery wastewater, which was in high NH4＋ -N concentratio...An intermittently aerated sequencing batch reactor （IASBR） and a traditional sequencing batch reactor （SBR） were parallelly constructed to treat digested piggery wastewater, which was in high NH4＋ -N concentration but in a low COD/TN ratio. Their pollutant removal perfonnance was compared under COD/TN ratios of 1.6-3.4 d and hydraulic retention times of 5 3 d. The results showed that the IASBR removed TN, NH4＋-N and TOC more efficiently than the SBR. The average removal rates of TN, NH4＋-N and TOC were 83.1%, 96.5%, and 89.0%, respectively, in the IASBR, significantly higher than the corresponding values of 74.8%, 82.0%, and 86.2%. in the SBR. Mass balance of organic carbon revealed that the higher TN removal in the IASBR might be attributed to its efficient utilization of the organic carbon for denitrification, since that 48.7%- 52.2% of COD was used for denitrification in the IASBR, higher than the corresponding proportion of 43.1%-47.4% in the SBR. A prc-anoxic process in the IASBR would enhance the ammonium oxidation while restrict the nitrite oxidation. Anoxic duration of 40-80 min should be beneficial for achieving stable nitritation.展开更多
Herein we provide a novel high-efficiency nanocomposite for bacterial capture based on mixed metal oxides(MMOs)with deleterious chromium properties.With both the layer structure of layered double hydroxides(LDHs)and t...Herein we provide a novel high-efficiency nanocomposite for bacterial capture based on mixed metal oxides(MMOs)with deleterious chromium properties.With both the layer structure of layered double hydroxides(LDHs)and the magnetic properties of Fe,MMOs enrich the location of ionic forms on the surface,providing a good carrier for adsorption of the heavy metal Cr(VI).The capacity for adsorption of Cr(VI)by MMOs can be as high as 98.80 mg/g.The prepared Cr(VI)-MMOs achieved extremely expeditious location of gram-negative antibiotic-resistant E.coliNDM-1 by identifying lipid bilayers.Cr-MMOs with a Cr loading of 19.70 mg/g had the best bactericidal effect,and the concentration of E.coliNDM-1 was decreased from~10^(8) to~10^(3) CFU/mL after 30 min of reaction.The binding of nitrogen and phosphorus hydrophilic groups to chromate generated realistic models for density functional theory(DFT)calculations.The specific selectivity of MMOs toward bacterial cells was improved by taking Cr(VI)as a transferable medium,thereby enhancing the antibacterial activity of Cr-MMOs.Under the combined action of chemical and physical reactions,Cr(VI)-MMOs achieved high capacity for inactivation of bacteria.Moreover,the metallic elements ratio in Cr-MMOs remained stable in their initial valence states after inactivation.This guaranteed high removal efficiency for both heavy metals and bacteria,allowing recycling of the adsorbent in practical applications.展开更多
基金supported by the Leading Talent of the Science and Technology Nova Program of Zhejiang(No.2020R52039)the Outstanding Innovative Team Supporting Plan of Jiaxing City(No.2022-LHYJ-02-0503-02)+1 种基金the Key Research Project of Yangtze Delta Region Institute of Tsinghua University(No.2023ZQZ005)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX22-1386).
文摘In this study,we analyzed the characteristics of three-dimensional excitation-emission matrix spectra(EEMs)of 150 samples from five industrial wastewater types and domestic sewage to track water pollution sources effectively.We then developed a recognition model for wastewater EEMs by establishing a feature dataset containing fluorescence peak values and parameters derived from EEMs,integrated with machine learning techniques.This model enables the rapid and precise identification of pollution sources.Our findings suggest that although the EEMs of the sixwastewater categories are distinct,visual differentiation is challenging.This was confirmed by cosine similarity assessments,showing some samples with low within-group(<0.8)and high between-group(>0.95)similarities.Despite significant variations in EEMs features acrosswastewater categories,identifying specific pollutants remains difficult,especially for pulp mills and leather effluents.Among the tested classification algorithms,Support Vector Machine(SVM)achieved the highest performance with91.7%accuracy,94%precision,91%recall,and 92%F_(1)-score,outperforming K-Nearest Neighbors and Partial Least Squares Discriminant Analysis.The SVM significantly improved identification accuracy for pulpmill and leather processing wastewaters compared to other models.To enhance identification accuracy,further exploration of EEMs features and expanding the training dataset are recommended.Combining EEMs features with machine learning presents a promising method for improvingwater pollution supervision and source tracing in environmental management practices.
基金funded by National High-Tech Research and Development Program(863)of China(No.2013AA062705-1)
文摘Adsorbable organic halogens（AOX） are a general indicator for the total amount of compounds containing organically bonded halogens. AOX concentrations and components were investigated along the wastewater treatment process in four large-scale pharmaceutical factories of China, and genotoxicity based on the SOS/umu test was also evaluated. The results showed that AOX concentrations in wastewater of four factories ranged from 4.6 to 619.4 mg/L, which were high but greatly different owing to differences in the raw materials and products. The wastewater treatment process removed 50.0%–89.9% of AOX, leaving 1.3–302.5 mg/L AOX in the effluents. Genotoxicity levels ranged between 2.1 and 68.0 μg 4-NQO/L in the raw wastewater and decreased to 1.2–41.2 μg 4-NQO/L in the effluents of the wastewater treatment plants（WWTPs）. One of the main products of factory I, ciprofloxacin, was identified as the predominant contributor to its genotoxicity. However, for the other three factories, no significant relationship was observed between genotoxicity and detected AOX compounds.
基金supported by the"863"Exploration Projectof the Ministry of Science and Technology of China(No.2009AA06Z309)the National Natural Science Foundation of China(No.51178002)the Science andTechnology Project of Zhejiang Province of China(No.2011C23064)
文摘The bacterial strain Paracoccus denitrificans W12, which could utilize pyridine as its sole source of carbon and nitrogen, was added into a membrane bioreactor （MBR） to enhance the treatment of a pharmaceutical wastewater. The treatment efliciencies investigated showed that the removal of chemical oxygen demand, total nitrogen, and total phosphorus were similar between bioaugmented and non-bioaugmented MBRs, however, significant removal of pyridine was obtained in the bioaugmented reactor. When the hydraulic retention time was 60 hr and the influent concentration of pyridine was 250-500 mg/L, the mean effluent concentration of pyridine without adding W12 was 57.2 mg/L, while the pyridine was degraded to an average of 10.2 mg/L with addition of W12. The bacterial community structure of activated sludge during the bioaugmented treatment was analyzed using polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE）. The results showed that the W12 inoculum reversed the decline of microbial community diversity, however, the similarity between bacterial community structure of the original sludge and that of the sludge after bioaugmentation decreased steadily during the wastewater treatment. Sequencing of the DNA recovered from DGGE gel indicated that sp., Sphingobium sp., Comamonas sp., and Hyphomicrobium sp. were the dominant organisms in time sequence in the bacterial community in the bioaugmented MBR. This implied that the bioaugmentation was affected by the adjustment of whole bacterial community structure in the inhospitable environment, rather than being due solely to the degradation performance of the bacterium added.
基金supported by the National Natural Science Foundation of China(No.51678334)
文摘The dynamic change of microbial community during sludge acclimation from aerobic to anaerobic in a MBR for coking wastewater treatment was revealed by Illumina Miseq sequencing in this study. The diversity of both Bacteria and Archaea showed an increase–decrease trajectory during acclimation, and exhibited the highest at the domestication interim. Ignavibacteria changed from a tiny minority（less than 1%） to the dominant bacterial group（54.0%） along with acclimation. The relative abundance of Betaproteobacteria kept relatively steady, as in this class some species increased coupled with some other species decreased during acclimation. The dominant Archaea shifted from Halobacteria in initial aerobic sludge to Methanobacteria in the acclimated anaerobic sludge. The dominant bacterial and archaeal groups in different acclimation stages were indigenous microorganisms in the initial sludge, though some of them were very rare. This study supported that the species in＂rare biosphere＂ might eventually become dominant in response to environmental change.
基金funded by the National High-Tech Research and Development Program (863 Program) of China (No. 2013AA062705-1)the National Natural Science Funds of China (No. 51308319)
文摘A recombinant human androgen receptor yeast assay was applied to investigate the occurrence of antiandrogens as well as the mechanism for their removal during gray wastewater and coking wastewater treatment. The membrane reactor（MBR） system for gray wastewater treatment could remove 88.0% of antiandrogenic activity exerted by weakly polar extracts and 97.3% of that by moderately strong polar extracts, but only 32.5%of that contributed by strong polar extracts. Biodegradation by microorganisms in the MBR contributed to 95.9% of the total removal. After the treatment, the concentration of antiandrogenic activity in the effluent was still 1.05 μg flutamide equivalence（FEQ）/L, 36.2%of which was due to strong polar extracts. In the anaerobic reactor, anoxic reactor, and membrane reactor system for coking wastewater treatment, the antiandrogenic activity of raw coking wastewater was 78.6 mg FEQ/L, and the effluent of the treatment system had only 0.34 mg FEQ/L. The antiandrogenic activity mainly existed in the medium strong polar and strong polar extracts. Biodegradation by microorganisms contributed to at least 89.2%of the total antiandrogenic activity removal in the system. Biodegradation was the main removal mechanism of antiandrogenic activity in both the wastewater treatment systems.
基金supported by the financial support by the National High Technology ResearchDevelopment Program of the Chinese Ministry of Science and Technology(No.2009AA063905)the Independent Research Project of Tsinghua University(No.20101081929)
文摘Diisopropylthiourea（DPT）, an intermediate of a widely used cephalosporin, has been found to be one of the most refractory components in cephalosporin synthesis wastewater.This compound cannot be completely removed by conventional biological processes due to its antimicrobial property. Ionizing radiation has been applied in the decomposition of refractory pollutants in recent years and has proved effective. Therefore, the decomposition of DPT by γ-irradiation was studied. The compound was irradiated at the dose of 150–2000 Gy before a change of concentration and UV absorption of the solutions was detected.Furthermore, the decomposition kinetics and radiation yield（G-value） of DPT was investigated. The results of radiation experiments on DPT-containing aqueous showed that the DPT can be effectively degraded by γ-radiation. DPT concentration decreased with increasing absorbed doses. G-values of radiolytic decomposition for DPT（20 mg/L） were 1.04 and 0.47 for absorbed doses of 150 and 2000 Gy, respectively. The initial concentration and p H of the solutions affected the degradation. As the concentration of substrate increased,the decomposition was reduced. The decrease of removal rate and radiation efficacy under alkaline condition suggested that lower p H values benefit the γ-induced degradation. UV absorption from 190 to 250 nm decreased after radiation while that from 250 to 300 nm increased, indicating the formation of by-products.
基金supported by the National High Technology Research and Development Program (No.2009AA063905)the General Research Program of Shanghai Normal University (No.SK201418)the Young Teacher Training Scheme of Shanghai Universities (No.ZZshsf14008)
文摘Ozonation and ionizing radiation are both advanced oxidation processes（AOPs） without chemical addition and secondary pollution. Also, the two processes＇ efficiency is determined by different p H conditions, which creates more possibilities for their combination. Importantly,the combined process of ozonation and ionizing radiation could be suitable for treating wastewaters with extreme p H values, i.e., textile wastewater. To find synergistic effects, the combined process of ozonation and ionizing radiation mineralization was investigated for degradation of polyvinyl alcohol（PVA） at different p H levels. A synergistic effect was found at initial p H in the range 3.0–9.4. When the initial p H was 3.0, the combined process of ozonation and ionizing radiation gave a PVA mineralization degree of 17%. This was 2.7 times the sum achieved by the two individual processes, and factors of 2.1 and 1.7 were achieved at initial p H of7.0 and 9.4, respectively. The combined process of ozonation and ionizing radiation was demonstrated to be a feasible strategy for treatment of PVA-containing wastewater.
基金the National Hi-Tech Research and Development Program(863)of China(No.2009AA063905)supported by the Chinese Ministry of Science and Technology and the Independent Research Project(No.20101081929)supported by Tsinghua University
文摘Recently, water treatment by ionizing radiation has gained increasing attention as a powerful technology for the destruction of refractory pollutants. 2-Mercaptobenzothiazole（MBT） is known as a widespread, toxic and poorly biodegradable pollutant. This paper studied the gamma irradiation of aqueous solutions of MBT. Moreover, the effect of the addition of persulfate（S2O82-） on the radiolytic destruction of MBT was investigated. The main transformation products of the studied compound were detected and the sequence of occurrence of the products was described. The change of biodegradability of MBT solution was also observed. The main results obtained in this study indicated that gamma radiation was effective for removing MBT in aqueous solution. Persulfate addition, which induced the formation of reactive sulfate radicals（SO4-U）, greatly enhanced the degradation of MBT. Benzothiazole was identified as the first radiation product, followed by 2-hydroxybenzothiazole. Decomposition of MBT started with the oxidation of –SH groups to sulfate ions. Possible pathways for MBT decomposition by gamma irradiation were proposed. The BOD/COD ratios of MBT samples were increased after radiation,indicating the improvement of biodegradability and reduction of toxicity.
基金supported by the National Natural Science Foundation of China(No.51308319)the International Cooperation Project(No.2013DFG92600)the Public Technology Applied Research Projects of Zhejiang Province(No.2015C33034)
文摘In this study, a lab-scale biological anaerobic/anaerobic/anoxic/membrane bioreactor （A3-MBR） was designed to treat wastewater from the ethanol fermentation of food waste, a promising way for the disposal of food waste and reclamation of resources. The 454 pyrosequencing technique was used to investigate the composition of the microbial community in the treatment system. The system yielded a stable effluent concentration of chemical oxygen demand （202 ± 23 mg/L）, total nitrogen （62.1 ± 7.1 mg/L）, ammonia （0.3 ±0.13 mg/L） and total phosphorus （8.3 ± 0.9 rag/L）, and the reactors played different roles in specific pollutant removal. The exploration of the microbial community in the system revealed that： （1） the microbial diversity of anaerobic reactors A1 and A2, in which organic pollutants were massively degraded, was much higher than that in anoxic A3 and aerobic MBR; （2） although the community composition in each reactor was quite different, bacteria assigned to the classes Clostridia, Bacteroidia, and Synergistia were important and common microorganisms for organic pollutant degradation in the anaerobic units, and bacteria from Alphaproteobacteria and Betaproteobacteria were the dominant microbial population in A3 and MBR; （3） the taxon identification indicated that Arcobacter in the anaerobic reactors and Thauera in the anoxic reactor were two representative genera in the biological process. Our results proved that the biological A3-MBR process is an alternative technique for treating wastewater from food waste.
基金supported by a General Project granted by the National Natural Science Foundation of China (No. 51178002)
文摘Anthropogenic activities usually contaminate water environments, and have led to the eutrophication of many estuaries and shifts in microbial communities. In this study, the temporal and spatial changes of the microbial community in an industrial effluent receiving area in Hangzhou Bay were investigated by 454 pyrosequencing. The bacterial community showed higher richness and biodiversity than the archaeal community in all sediments. Proteobacteria dominated in the bacterial communities of all the samples; MarineGroupⅠand Methanomicrobia were the two dominant archaeal classes in the effluent receiving area. PCoA and AMOVA revealed strong seasonal but minor spatial changes in both bacterial and archaeal communities in the sediments. The seasonal changes of the bacterial community were less significant than those of the archaeal community, which mainly consisted of fluctuations in abundance of a large proportion of longstanding species rather than the appearance and disappearance of major archaeal species. Temperature was found to positively correlate with the dominant bacteria, Betaproteobacteria, and negatively correlate with the dominant archaea,MarineGroupⅠ; and might be the primary driving force for the seasonal variation of the microbial community.
文摘A biofilm membrane bioreactor （BF-MBR） and a conventional membrane bioreactor （MBR） were parallelly operated for treating digested piggery wastewater. The removal performance of COD, TN, NH4＋-N, TP as well as antibiotics were simultaneously studied when the hydraulic retention time （HRT） was gradually shortened from 9 d to 1 d and when the ratio ofinfluent COD to TN was changed. The results showed that the effluent quality in both reactors was poor and unstable at an influent COD/ TN ratio of 1.0±0.2. The effluent quality was signifcantly improved as the influent COD/TN ratio was increased to 2.3±0.5. The averaged removal rates of COD, NH4＋-N, TN and TP were 92.1%, 97.1%, 35.6% and 54.2%, respectively, in the BF-MBR, significantly higher than the corresponding values of 91.7%, 90.9%, 17.4% and 31.9% in the MBR. Analysis of 11 typical veterinary antibiotics （from the tetracycline, sulfonamide, quinolone, and macrolide families） revealed that the BF-MBR removed more antibiotics than the MBR. Although the antibiotics removal decreased with a shortened HRT, high antibiotics removals of 86.8%, 80.2% and 45.3% were observed in the BF-MBR at HRT of 5~4 d, 3-2 d and 1 d, respectively, while the corresponding values were only 83.8%, 57.0% and 25.5% in the MBR. Moreover, the BF-MBR showed a 15% higher retention rate of antibiotics and consumed 40% less alkalinity than the MBR. Results above suggest that the BF-MBR was more suitable for digested piggery wastewater treatment.
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%.
文摘An intermittently aerated sequencing batch reactor （IASBR） and a traditional sequencing batch reactor （SBR） were parallelly constructed to treat digested piggery wastewater, which was in high NH4＋ -N concentration but in a low COD/TN ratio. Their pollutant removal perfonnance was compared under COD/TN ratios of 1.6-3.4 d and hydraulic retention times of 5 3 d. The results showed that the IASBR removed TN, NH4＋-N and TOC more efficiently than the SBR. The average removal rates of TN, NH4＋-N and TOC were 83.1%, 96.5%, and 89.0%, respectively, in the IASBR, significantly higher than the corresponding values of 74.8%, 82.0%, and 86.2%. in the SBR. Mass balance of organic carbon revealed that the higher TN removal in the IASBR might be attributed to its efficient utilization of the organic carbon for denitrification, since that 48.7%- 52.2% of COD was used for denitrification in the IASBR, higher than the corresponding proportion of 43.1%-47.4% in the SBR. A prc-anoxic process in the IASBR would enhance the ammonium oxidation while restrict the nitrite oxidation. Anoxic duration of 40-80 min should be beneficial for achieving stable nitritation.
基金support by the National Key Research and Development Program of China(No.2017YFA0207203)National Natural Science Foundation of China(Grant No.51978195).
文摘Herein we provide a novel high-efficiency nanocomposite for bacterial capture based on mixed metal oxides(MMOs)with deleterious chromium properties.With both the layer structure of layered double hydroxides(LDHs)and the magnetic properties of Fe,MMOs enrich the location of ionic forms on the surface,providing a good carrier for adsorption of the heavy metal Cr(VI).The capacity for adsorption of Cr(VI)by MMOs can be as high as 98.80 mg/g.The prepared Cr(VI)-MMOs achieved extremely expeditious location of gram-negative antibiotic-resistant E.coliNDM-1 by identifying lipid bilayers.Cr-MMOs with a Cr loading of 19.70 mg/g had the best bactericidal effect,and the concentration of E.coliNDM-1 was decreased from~10^(8) to~10^(3) CFU/mL after 30 min of reaction.The binding of nitrogen and phosphorus hydrophilic groups to chromate generated realistic models for density functional theory(DFT)calculations.The specific selectivity of MMOs toward bacterial cells was improved by taking Cr(VI)as a transferable medium,thereby enhancing the antibacterial activity of Cr-MMOs.Under the combined action of chemical and physical reactions,Cr(VI)-MMOs achieved high capacity for inactivation of bacteria.Moreover,the metallic elements ratio in Cr-MMOs remained stable in their initial valence states after inactivation.This guaranteed high removal efficiency for both heavy metals and bacteria,allowing recycling of the adsorbent in practical applications.
