A series of batch experiments were conducted in 125 mL serum bottles to assess the toxicity of different concentrations of ammonia nitrogen to the specific methanogenic activity of anaerobic granular sludge from upflo...A series of batch experiments were conducted in 125 mL serum bottles to assess the toxicity of different concentrations of ammonia nitrogen to the specific methanogenic activity of anaerobic granular sludge from upflow anaerobic sludge bed（UASB） and expanded granular sludge bed（EGSB） reactors. The effects of pH value and temperature on toxicity of ammonia nitrogen to anaerobes were investigated. The results show that the specific methanogenic activity of anaerobic granular sludge suffers inhibition from ammonia nitrogen, the concentrations of ammonia nitrogen that produce 50 % inhibition of specific methanogenic activity for sludge from UASB and EGSB reactor are 2.35 and 2.75 g/L, respectively. Hydrogen utilizing methanogens suffers less inhibition from ammonia mtrogen than that of acetate utilizing methanogens. Hydrogen-producing acetogens that utilize propionate and butyrate as substrates suffer serious inhibition from ammonia nitrogen. The toxicity of ammonia nitrogen to anaerobic granular sludge enhances when pH value and temperature increase. Anaerobic granular sludge can bear higher concentrations of ammonia nitrogen after being acclimated by ammonia nitrogen for 7 d.展开更多
Large amounts of ammonium and a low content of biodegradable chemical oxygen demand（COD） are contained in leachate from aged landfills, together with the effluent containing high concentration of nitric nitrogen aft...Large amounts of ammonium and a low content of biodegradable chemical oxygen demand（COD） are contained in leachate from aged landfills, together with the effluent containing high concentration of nitric nitrogen after biochemical treatment. Treatment effect of anaerobic ammonium oxidation （anammox） process on the mixture of the leachate and its biochemical effluent was investigated. The results show that the average removal efficiencies of ammonium, nitric nitrogen and total nitrogen are 87.51%, 74.95% and 79.59%, respectively, corresponding to the average ratio of removed nitric nitrogen to ammonium, i.e. 1.14 during the steady phase of anammox activity. The mean removal efficiency of COD is only 24.01% during the experimental period. Thc,dcmand of total phosphorous for the anammox process is unobvious. Especially, the alkalinity and pH value of the effluent are close to those of the inftuent during the steady phase of anammox activity. In addition, it is demonstrated that the status of the anammox bioreactor can be indicated by the alkalinity and pH value during the course of the experiment. The anammox bioreactor has shown potential for nitrogen removal in the leachate mixture. However, COD and total phosphorous in the leachate mixture need further treatment for removal efficiencies of COD and total phosphorous are not good in the anammox bioreactor.展开更多
Anaerobic co-digestion of food waste（FW） and rice straw（RS） in continuously stirred tank reactor（CSTR） at high organic loading rate（OLR） was investigated. Co-digestion studies of FW and RS with six different m...Anaerobic co-digestion of food waste（FW） and rice straw（RS） in continuously stirred tank reactor（CSTR） at high organic loading rate（OLR） was investigated. Co-digestion studies of FW and RS with six different mixing ratios were conducted at an initial volatile solid（VS） concentration of more than 3 g VS · L-1. The biogas production, methane contents, degradation efficiency of VS, chemical oxygen demand（COD） and volatile fatty acids（VFAs） were determined to evaluate the stability and performance of the system. The results showed that the co-digestion process had higher system stability and higher volumetric biogas production than mono-digestions. Increase in FW content in the feedstock could increase the methane yield and shorten retention time. The efficiency of co-digestion systems mainly relied on the mixing ratios of FW and RS to some extent. The highest methane yield was 60.55 m L· g V· S-1 · d-1 at a mass ratio（FW/RS） of 3 ： 1, which was 178% and 70% higher than that of mono-digestions of FW and RS, respectively. Consequently, the anaerobic co-digestion of FW and RS could have superior stability and better performance than monodigestions in higher organic loading system.展开更多
In the present study,mRNA levels of the ArcA gene of Actinobacillus pleuropneumoniae serotype1 were measured during response to stress by growing under anaerobic conditions.Expression levels were measured by semi-quan...In the present study,mRNA levels of the ArcA gene of Actinobacillus pleuropneumoniae serotype1 were measured during response to stress by growing under anaerobic conditions.Expression levels were measured by semi-quantitative RT-PCR using the housekeeping gene recF as an internal standard.The expression of ArcA was undetectable until about 3 hours under standard culture conditions,but it was promptly and highly expressed in anaerobic culture.The results are consistent with ArcA being a potential virulence gene of Actinobacillus pleuropneumoniae,and likely playing an important role in pathogenesis caused by this organism.展开更多
The profile of hydrolysates during the anaerobic digestion of kitchen wastes was investigated. The experimental results show that the hysteresis of hydrolytic rate is mainly controlled by the diffusion effect. The hyd...The profile of hydrolysates during the anaerobic digestion of kitchen wastes was investigated. The experimental results show that the hysteresis of hydrolytic rate is mainly controlled by the diffusion effect. The hydrolytic mechanism of kitchen wastes is elaborated by taking the diffusion effect into consideration. A segment model of the hydrolysis for kitchen waste is formulated including the coefficient of diffusion resistance in the model. The coefficients of diffusion resistance for different particle sizes are 1.42,2.12 and 2.78 respectively based on the experimental data,in which the coefficients of diffusion resistance conform an exponential function. So,the partitioning kinetic model could be integrated as a unified experience model. The model is verified with experimental data,which shows that the model could predict the concentration of organic substances during the anaerobic digestion of kitchen wastes.展开更多
The anaerobic digestion of septic sludge was studied through inoculating effective microorganisms (EMs) under mesophilic condition (35 ℃). The variation of COD,total solid (TS),volatile solid (VS),pH value and the ga...The anaerobic digestion of septic sludge was studied through inoculating effective microorganisms (EMs) under mesophilic condition (35 ℃). The variation of COD,total solid (TS),volatile solid (VS),pH value and the gas production rate during the digestion process were presented,and the optimal adding concentration of EMs was determined by comparing the reduction effectiveness of septic sludge. The results show that proper addition of EMs can enhance acid buffering capacity of the system,and the NH3-N concentration is lower than inhibition concentration of 2 g/L reported in the literature and maintain the range of pH value which is suitable for both hydrolysis-acidification and methanogenesis. However,overdose of EMs can reduce the initial pH value of septic sludge and decrease the effects of the anaerobic digestion. EMs can increase the quantity of microbe in septic sludge and improve the gas production and generation rate over a period of time. But overdosing EMs can lead to low pH,restrain activity of methanogenic bacteria and affect the quantity and the generation rate of gas. Adding 0.01% EMs achieves the highest sludge reduction with the removal rates of TS,VS and COD by 32.51%,42.34% and 40.97%,respectively.展开更多
This article, based on investigation and analysis, existed anaerobic fermentation equipment, with a view to the production of high-latitude area, pointed out the thought of exploiting efficient anaerobic fermentation ...This article, based on investigation and analysis, existed anaerobic fermentation equipment, with a view to the production of high-latitude area, pointed out the thought of exploiting efficient anaerobic fermentation equipment, including： the settting independent equipment of acidogenic phase and methanogenic phase; the applying conbination of AF and UASB in methanogenic phase; adopting efficient sludge inverse flowing equipment and the technique of flora enrichment, and efficient method of saving energy and thermal retardation; adopting autocontrol which could make the equipment run efficiently and stably.展开更多
Twenty-nine facultative anaerobic cellulose-degrading bacteria were isolated from soil, rumen fluid, rumen residues and diet of dairy cow. Based on 16 Sr DNA analysis by BLAST algorithm method, the results showed that...Twenty-nine facultative anaerobic cellulose-degrading bacteria were isolated from soil, rumen fluid, rumen residues and diet of dairy cow. Based on 16 Sr DNA analysis by BLAST algorithm method, the results showed that most of the strains were Bacillus genera, and six of the 29 strains were bigger than 10 mm of diameter of clear zones. For them, two strains were isolated from rumen fluid(L5 and L7) and other two were isolated from rumen residue(N5 and N9), while others were isolated from soil(T1) and diet(S6), respectively. Strains from rumen fluid and residue had higher activities of FPCase and CMCase, but lower β-glucosidases.展开更多
Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,...Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,after which all experimental groups were digested at 35℃for 24 days.This pretreatment method efficiently broke the lignocellulose structure of the corn stalk.Different from the volatile fatty acids(VFAs)content,the pH and RS contents were relatively higher than those of the control during the pretreatment process.Furthermore,the highest methane production[185.03 mL•g-1 VS(volatile solid)]was achieved at 55.46%under 35℃in 6 h,which was higher than that of the normal corn stalk anaerobic digestion.The VFAs contents and pH increased compared to CK upon the addition of NaOH to adjust pH,and the RS content also increased slightly due to the degradability of lignocellulose during the whole-slurry anaerobic co-digestion.This work provided a potential method to sustainably treat wastewater and improve fermentation performance.展开更多
Manure slurry application to farmland reduces chemical fertilizer use,mitigates pollution,and improves soil fertility.However,researches on the role of anaerobically treated cow slurry applied to soil microorganisms i...Manure slurry application to farmland reduces chemical fertilizer use,mitigates pollution,and improves soil fertility.However,researches on the role of anaerobically treated cow slurry applied to soil microorganisms in Northeast China remain underexplored.Here,in laboratory incubation experiments,different treatments including various combinations of sterilized and non-sterilized soil and slurry,and different application rates were employed to examine the effects of indigenous microorganisms on soil microbial communities.Field-collected soil samples were employed to examine the responses and spatial variations of soil microbes under production conditions.The results indicated that indigenous soil microorganisms exerted a dominant influence in the microbial community variations,while the impact of cow slurry microbiota on community diversity was relatively minor.At the phylum level,Proteobacteria(P=0.031,R=0.969)showed a significant positive correlation with the slurry application,whereas Acidobacteriota(P=0.012,R=–0.988)and Basidiomycota(P=0.01,R=–0.99)showed significant negative correlations.In the field environment,the autumn slurry application effects on soil microbes in the following year were not significant.In contrast,under spring slurry application,the cow slurry-soil agglomerations led to significant spatial differences in soil microbial communities,with higher microbial diversity observed in the vicinity of agglomerations.The microbes in agglomerations,such as Actinomycetes,Bacteroides and Proteobacteria,were found to be beneficial for the crop residue decomposition.These microorganisms could decompose organic compounds including lignin,cellulose,hemicellulose,and xylan in crop straw.Overall,slurry application indeed influenced soil microbes and induced spatial variations,providing insights for sustainable agricultural practices.展开更多
2,4,6-trinitrotoluene(TNT) and its derivatives are nitrogen-containing aromatic compounds having chemical and thermal stability at ambient temperature and pressure. TNT has high toxicity and mutagenic activity to huma...2,4,6-trinitrotoluene(TNT) and its derivatives are nitrogen-containing aromatic compounds having chemical and thermal stability at ambient temperature and pressure. TNT has high toxicity and mutagenic activity to humans, plants and animals, thus decontamination processes are necessary. Many microorganisms are capable to bioremediate TNT such as bacteria from the genera Pseudomonas,Enterobacter, Rhodococcus, Mycobacterium, Clostridium and Desulfovibrio: fungus such as Phanerochate and Stropharia species are able to perform TNT biotransformation under aerobic and anaerobic conditions. In this work we review the state of TNT biodegradation by various routes: aerobic, anaerobic,combined, fungal, enzymatic, and bio-electrochemical.展开更多
A full-scale experimental study of treating mustard wastewater by the integrated bioreactor with designed scale of 1 000 m3/d is conducted combined with a demonstration project. The systematical researches on the effi...A full-scale experimental study of treating mustard wastewater by the integrated bioreactor with designed scale of 1 000 m3/d is conducted combined with a demonstration project. The systematical researches on the efficiency of combined operation conditions of anaerobic-aerobic and anaerobic-aerobic-flocculation as well as chemical phosphorus removal of hypersaline mustard wastewater are conducted. The optimal operation condition and parameters in pretreatment of mustard wastewater in winter （the water temperature ranges 8-15 ~C） are determined： the anaerobic load is 3.0 kg （COD）/（m3.d）, the average COD and phosphate concentration of the inflow are respectively 3 883 mg/L and 35.53 mg/L and the dosage of flocculent （PAC） is 400 mg/L. The anaerobic-aerobic-flocculation combined operation condition and postpositive phosphorous removal with ferrous sulfate are employed. After treatment, the COD of the effluent is 470 mg/L and the average phosphate concentration is 5.09 mg/L. The effluent could achieve the third-level of Integrated Wastewater Discharge Standard （GB 8978--1996）.展开更多
The easy acidification and high hydrogen sulfide （H2S） production during anaerobic digestion of macroalgae limited its application in biomethane production. In order to investigate the effects of ceramsite on methan...The easy acidification and high hydrogen sulfide （H2S） production during anaerobic digestion of macroalgae limited its application in biomethane production. In order to investigate the effects of ceramsite on methane and HzS productions during anaerobic digestion of macroalgae, batch experiments ofMacrocystis pyrifera were carried out. Four groups named C0, C1, C2 and C3 added with 0, 1.5, 3.0 and 4.5 g/g substrate of ceramsite, respectively, were studied and compared. The highest cumulative methane yield of 286.3 mL/g substrate is obtained in C2, which is 40.11% higher than that of CO. The cumulative HzS yields of C1, C2 and C3 are 32.67%, 44.66% and 53.21% lower than that of CO, respectively. Results indicate that ceramsite addition permits higher methane yields, shorter lag-phase time and lower HzS yields during anaerobic digestion of Macrocystispyrifera.展开更多
The analysis of seven aliphatic carboxylic acids(formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion ...The analysis of seven aliphatic carboxylic acids(formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents(benzoic acid,perfluorobutyric acid(PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet(UV) detection.The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column(TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column(TSKgel Super IC-A/C).Good separation was performed on the TSKgel SCX in shorter retention times.For the TSKgel Super IC-A/C,peak shape of the acids was sharp and symmetrical in spite of longer retention times.In addition,the mutual separation of the acids was good except for iso-and n-butyric acids.The better separation and good detection was achieved by using the two columns(TSKgel SCX and TSKgel Super IC-A/C connected in series),lower concentrations of PFBA and sulfuric acid as eluents,non-suppressed conductivity detection and UV detection at 210 nm.This analysis was applied to anaerobic digestion process waters.The chromatograms with conductivity detection were relatively simpler compared with those of UV detection.The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.展开更多
Activity on catalytic reduction of C<sub>2</sub>H<sub>2</sub> for seven Mo-Fe-S cluster compounds (I. （Et<sub>4</sub>N<sub>4</sub>）<sub>4</sub>[Mo<sub&g...Activity on catalytic reduction of C<sub>2</sub>H<sub>2</sub> for seven Mo-Fe-S cluster compounds (I. （Et<sub>4</sub>N<sub>4</sub>）<sub>4</sub>[Mo<sub>2</sub>Fe<sub>2</sub>S<sub>10</sub>]·2CH<sub>3</sub>OH, Ⅱ. Mo<sub>2</sub>Fe<sub>2</sub>S<sub>4</sub>（S<sub>2</sub>CNEt<sub>2</sub>）<sub>5</sub>·CH<sub>3</sub>CN, Ⅲ. （Bu<sub>4</sub>N）<sub>3</sub> [Mo<sub>2</sub>FeS<sub>8</sub>O]·Ⅳ·（Et<sub>4</sub>N）<sub>3</sub>[Mo<sub>2</sub>FeS<sub>8</sub>O<sub>2</sub>], V. （Et<sub>4</sub>N）<sub>2</sub>[MoFeS<sub>4</sub>（SCN）<sub>2</sub>（OCH<sub>3</sub>）<sub>2</sub>]·3CH<sub>3</sub>OH, Ⅵ. （Et<sub>4</sub>N）<sub>3</sub>[Mo<sub>2</sub>FeS<sub>8</sub>O（OCH<sub>3</sub>）<sub>2</sub>], Ⅶ. （Et<sub>4</sub>N）<sub>4</sub>Mo<sub>2</sub>Fe<sub>7</sub>S<sub>12</sub>（SPh）<sub>6</sub>·6CH<sub>3</sub>OH), three Fe-S cluster compounds （Ⅷ.（Et<sub>4</sub>N）<sub>2</sub>[Fe<sub>4</sub>S<sub>4</sub>（S<sub>2</sub>CNEt<sub>2</sub>）<sub>4</sub>], Ⅸ. （Bu<sub>4</sub>N）<sub>2</sub>[Fe<sub>4</sub>S<sub>3</sub>（SC（CH<sub>3</sub>）<sub>3</sub>）<sub>4</sub>], Ⅹ. （Bu<sub>4</sub>N）[Fe<sub>2</sub>S<sub>3</sub>（SCH<sub>2</sub>Ph）<sub>2</sub>]） and combination systems of related compounds, has been determined under anaerobic conditions at 25℃ and with KBH<sub>4</sub> as the reductant. In addition, at 15℃, under otherwise the same conditions, activity on catalytic reduction of C<sub>2</sub>H<sub>2</sub> for different constituent systems from （NH<sub>4</sub>）<sub>2</sub>MoS<sub>4</sub> and FeCl<sub>3</sub> has also been determined.展开更多
文摘A series of batch experiments were conducted in 125 mL serum bottles to assess the toxicity of different concentrations of ammonia nitrogen to the specific methanogenic activity of anaerobic granular sludge from upflow anaerobic sludge bed（UASB） and expanded granular sludge bed（EGSB） reactors. The effects of pH value and temperature on toxicity of ammonia nitrogen to anaerobes were investigated. The results show that the specific methanogenic activity of anaerobic granular sludge suffers inhibition from ammonia nitrogen, the concentrations of ammonia nitrogen that produce 50 % inhibition of specific methanogenic activity for sludge from UASB and EGSB reactor are 2.35 and 2.75 g/L, respectively. Hydrogen utilizing methanogens suffers less inhibition from ammonia mtrogen than that of acetate utilizing methanogens. Hydrogen-producing acetogens that utilize propionate and butyrate as substrates suffer serious inhibition from ammonia nitrogen. The toxicity of ammonia nitrogen to anaerobic granular sludge enhances when pH value and temperature increase. Anaerobic granular sludge can bear higher concentrations of ammonia nitrogen after being acclimated by ammonia nitrogen for 7 d.
基金Project (20377013) supported by the National Natural Science Foundation of China project (020959) supported by Department of Science and Technology of Guangdong Province
文摘Large amounts of ammonium and a low content of biodegradable chemical oxygen demand（COD） are contained in leachate from aged landfills, together with the effluent containing high concentration of nitric nitrogen after biochemical treatment. Treatment effect of anaerobic ammonium oxidation （anammox） process on the mixture of the leachate and its biochemical effluent was investigated. The results show that the average removal efficiencies of ammonium, nitric nitrogen and total nitrogen are 87.51%, 74.95% and 79.59%, respectively, corresponding to the average ratio of removed nitric nitrogen to ammonium, i.e. 1.14 during the steady phase of anammox activity. The mean removal efficiency of COD is only 24.01% during the experimental period. Thc,dcmand of total phosphorous for the anammox process is unobvious. Especially, the alkalinity and pH value of the effluent are close to those of the inftuent during the steady phase of anammox activity. In addition, it is demonstrated that the status of the anammox bioreactor can be indicated by the alkalinity and pH value during the course of the experiment. The anammox bioreactor has shown potential for nitrogen removal in the leachate mixture. However, COD and total phosphorous in the leachate mixture need further treatment for removal efficiencies of COD and total phosphorous are not good in the anammox bioreactor.
基金Supported by the Natural Science Foundation of Heilongjiang Province(QC2014C031)Returned Overseas Foundation of Heilongjiang Province(LC2013C07)+2 种基金Outstanding Academic Leaders Foundation of Harbin City(2013RFXYJ015)Young Reserve Talent Foundation of Harbin City(2014RFQYJ141)Outstanding Young Foundation of Heilongjiang Academy of Agricultural Sciences(2013JCQN003)
文摘Anaerobic co-digestion of food waste（FW） and rice straw（RS） in continuously stirred tank reactor（CSTR） at high organic loading rate（OLR） was investigated. Co-digestion studies of FW and RS with six different mixing ratios were conducted at an initial volatile solid（VS） concentration of more than 3 g VS · L-1. The biogas production, methane contents, degradation efficiency of VS, chemical oxygen demand（COD） and volatile fatty acids（VFAs） were determined to evaluate the stability and performance of the system. The results showed that the co-digestion process had higher system stability and higher volumetric biogas production than mono-digestions. Increase in FW content in the feedstock could increase the methane yield and shorten retention time. The efficiency of co-digestion systems mainly relied on the mixing ratios of FW and RS to some extent. The highest methane yield was 60.55 m L· g V· S-1 · d-1 at a mass ratio（FW/RS） of 3 ： 1, which was 178% and 70% higher than that of mono-digestions of FW and RS, respectively. Consequently, the anaerobic co-digestion of FW and RS could have superior stability and better performance than monodigestions in higher organic loading system.
基金supported by the Biotechnological Key Project of Sichuan Province,China(05NG020-016)The Yangtze River Scholar and Innovation Team develop Project of Ministry of Education,China(IRT0555-9)
文摘In the present study,mRNA levels of the ArcA gene of Actinobacillus pleuropneumoniae serotype1 were measured during response to stress by growing under anaerobic conditions.Expression levels were measured by semi-quantitative RT-PCR using the housekeeping gene recF as an internal standard.The expression of ArcA was undetectable until about 3 hours under standard culture conditions,but it was promptly and highly expressed in anaerobic culture.The results are consistent with ArcA being a potential virulence gene of Actinobacillus pleuropneumoniae,and likely playing an important role in pathogenesis caused by this organism.
文摘The profile of hydrolysates during the anaerobic digestion of kitchen wastes was investigated. The experimental results show that the hysteresis of hydrolytic rate is mainly controlled by the diffusion effect. The hydrolytic mechanism of kitchen wastes is elaborated by taking the diffusion effect into consideration. A segment model of the hydrolysis for kitchen waste is formulated including the coefficient of diffusion resistance in the model. The coefficients of diffusion resistance for different particle sizes are 1.42,2.12 and 2.78 respectively based on the experimental data,in which the coefficients of diffusion resistance conform an exponential function. So,the partitioning kinetic model could be integrated as a unified experience model. The model is verified with experimental data,which shows that the model could predict the concentration of organic substances during the anaerobic digestion of kitchen wastes.
基金Project(2008BB7048) supported by Natural Science Foundation of CQ CSTC
文摘The anaerobic digestion of septic sludge was studied through inoculating effective microorganisms (EMs) under mesophilic condition (35 ℃). The variation of COD,total solid (TS),volatile solid (VS),pH value and the gas production rate during the digestion process were presented,and the optimal adding concentration of EMs was determined by comparing the reduction effectiveness of septic sludge. The results show that proper addition of EMs can enhance acid buffering capacity of the system,and the NH3-N concentration is lower than inhibition concentration of 2 g/L reported in the literature and maintain the range of pH value which is suitable for both hydrolysis-acidification and methanogenesis. However,overdose of EMs can reduce the initial pH value of septic sludge and decrease the effects of the anaerobic digestion. EMs can increase the quantity of microbe in septic sludge and improve the gas production and generation rate over a period of time. But overdosing EMs can lead to low pH,restrain activity of methanogenic bacteria and affect the quantity and the generation rate of gas. Adding 0.01% EMs achieves the highest sludge reduction with the removal rates of TS,VS and COD by 32.51%,42.34% and 40.97%,respectively.
基金Supported by National Natural Sciences Foundation(20040224001)
文摘This article, based on investigation and analysis, existed anaerobic fermentation equipment, with a view to the production of high-latitude area, pointed out the thought of exploiting efficient anaerobic fermentation equipment, including： the settting independent equipment of acidogenic phase and methanogenic phase; the applying conbination of AF and UASB in methanogenic phase; adopting efficient sludge inverse flowing equipment and the technique of flora enrichment, and efficient method of saving energy and thermal retardation; adopting autocontrol which could make the equipment run efficiently and stably.
基金Supported by Northeast Agricultural University Innovation Funding for Postgraduate(yjscx14007)China Agriculture Research System(CARS-37)
文摘Twenty-nine facultative anaerobic cellulose-degrading bacteria were isolated from soil, rumen fluid, rumen residues and diet of dairy cow. Based on 16 Sr DNA analysis by BLAST algorithm method, the results showed that most of the strains were Bacillus genera, and six of the 29 strains were bigger than 10 mm of diameter of clear zones. For them, two strains were isolated from rumen fluid(L5 and L7) and other two were isolated from rumen residue(N5 and N9), while others were isolated from soil(T1) and diet(S6), respectively. Strains from rumen fluid and residue had higher activities of FPCase and CMCase, but lower β-glucosidases.
基金Supported by the Technological Project of Heilongjiang Province"the Open Competition Mechanism to Select the Best Candidates"(2022ZXJ05C01-03)。
文摘Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,after which all experimental groups were digested at 35℃for 24 days.This pretreatment method efficiently broke the lignocellulose structure of the corn stalk.Different from the volatile fatty acids(VFAs)content,the pH and RS contents were relatively higher than those of the control during the pretreatment process.Furthermore,the highest methane production[185.03 mL•g-1 VS(volatile solid)]was achieved at 55.46%under 35℃in 6 h,which was higher than that of the normal corn stalk anaerobic digestion.The VFAs contents and pH increased compared to CK upon the addition of NaOH to adjust pH,and the RS content also increased slightly due to the degradability of lignocellulose during the whole-slurry anaerobic co-digestion.This work provided a potential method to sustainably treat wastewater and improve fermentation performance.
基金Supported by the China Postdoctoral Science Foundation(2021M700742)Heilongjiang Postdoctoral Fund(LBH–Z21109)。
文摘Manure slurry application to farmland reduces chemical fertilizer use,mitigates pollution,and improves soil fertility.However,researches on the role of anaerobically treated cow slurry applied to soil microorganisms in Northeast China remain underexplored.Here,in laboratory incubation experiments,different treatments including various combinations of sterilized and non-sterilized soil and slurry,and different application rates were employed to examine the effects of indigenous microorganisms on soil microbial communities.Field-collected soil samples were employed to examine the responses and spatial variations of soil microbes under production conditions.The results indicated that indigenous soil microorganisms exerted a dominant influence in the microbial community variations,while the impact of cow slurry microbiota on community diversity was relatively minor.At the phylum level,Proteobacteria(P=0.031,R=0.969)showed a significant positive correlation with the slurry application,whereas Acidobacteriota(P=0.012,R=–0.988)and Basidiomycota(P=0.01,R=–0.99)showed significant negative correlations.In the field environment,the autumn slurry application effects on soil microbes in the following year were not significant.In contrast,under spring slurry application,the cow slurry-soil agglomerations led to significant spatial differences in soil microbial communities,with higher microbial diversity observed in the vicinity of agglomerations.The microbes in agglomerations,such as Actinomycetes,Bacteroides and Proteobacteria,were found to be beneficial for the crop residue decomposition.These microorganisms could decompose organic compounds including lignin,cellulose,hemicellulose,and xylan in crop straw.Overall,slurry application indeed influenced soil microbes and induced spatial variations,providing insights for sustainable agricultural practices.
基金the Director of the School of Engineering and Science, Tecnológico de Monterrey, Campus Monterrey for his encouragement and financial supportthe financial support from CONACYT(Mexico)PhD scholarship No. 309171 for CCZ, SNI-C fellowship to RC and MR, FRAavesh green sustainability solutions S. De R. L. De. C. V. for their support
文摘2,4,6-trinitrotoluene(TNT) and its derivatives are nitrogen-containing aromatic compounds having chemical and thermal stability at ambient temperature and pressure. TNT has high toxicity and mutagenic activity to humans, plants and animals, thus decontamination processes are necessary. Many microorganisms are capable to bioremediate TNT such as bacteria from the genera Pseudomonas,Enterobacter, Rhodococcus, Mycobacterium, Clostridium and Desulfovibrio: fungus such as Phanerochate and Stropharia species are able to perform TNT biotransformation under aerobic and anaerobic conditions. In this work we review the state of TNT biodegradation by various routes: aerobic, anaerobic,combined, fungal, enzymatic, and bio-electrochemical.
基金Project(20090191120036) supported by the Fund of Doctoral Program of Ministry of Education,China
文摘A full-scale experimental study of treating mustard wastewater by the integrated bioreactor with designed scale of 1 000 m3/d is conducted combined with a demonstration project. The systematical researches on the efficiency of combined operation conditions of anaerobic-aerobic and anaerobic-aerobic-flocculation as well as chemical phosphorus removal of hypersaline mustard wastewater are conducted. The optimal operation condition and parameters in pretreatment of mustard wastewater in winter （the water temperature ranges 8-15 ~C） are determined： the anaerobic load is 3.0 kg （COD）/（m3.d）, the average COD and phosphate concentration of the inflow are respectively 3 883 mg/L and 35.53 mg/L and the dosage of flocculent （PAC） is 400 mg/L. The anaerobic-aerobic-flocculation combined operation condition and postpositive phosphorous removal with ferrous sulfate are employed. After treatment, the COD of the effluent is 470 mg/L and the average phosphate concentration is 5.09 mg/L. The effluent could achieve the third-level of Integrated Wastewater Discharge Standard （GB 8978--1996）.
基金Project(2014BAC31B01)supported by the National Science&Technology Support during the 12th Five-Year Plan Period,ChinaProjects(2015GSF117016,2015GSF115037)supported by the Key Research&Development Project of Shandong Province,China
文摘The easy acidification and high hydrogen sulfide （H2S） production during anaerobic digestion of macroalgae limited its application in biomethane production. In order to investigate the effects of ceramsite on methane and HzS productions during anaerobic digestion of macroalgae, batch experiments ofMacrocystis pyrifera were carried out. Four groups named C0, C1, C2 and C3 added with 0, 1.5, 3.0 and 4.5 g/g substrate of ceramsite, respectively, were studied and compared. The highest cumulative methane yield of 286.3 mL/g substrate is obtained in C2, which is 40.11% higher than that of CO. The cumulative HzS yields of C1, C2 and C3 are 32.67%, 44.66% and 53.21% lower than that of CO, respectively. Results indicate that ceramsite addition permits higher methane yields, shorter lag-phase time and lower HzS yields during anaerobic digestion of Macrocystispyrifera.
文摘The analysis of seven aliphatic carboxylic acids(formic,acetic,propionic,iso-butyric,n-butyric,iso-valeric and n-valeric acid) in anaerobic digestion process waters for biogas production was examined by ion-exclusion chromatography with dilute acidic eluents(benzoic acid,perfluorobutyric acid(PFBA) and sulfuric acid) and non-suppressed conductivity/ultraviolet(UV) detection.The columns used were a styrene/divinylbenzene-based strongly acidic cation-exchange resin column(TSKgel SCX) and a polymethacrylate-based weakly acidic cation-exchange resin column(TSKgel Super IC-A/C).Good separation was performed on the TSKgel SCX in shorter retention times.For the TSKgel Super IC-A/C,peak shape of the acids was sharp and symmetrical in spite of longer retention times.In addition,the mutual separation of the acids was good except for iso-and n-butyric acids.The better separation and good detection was achieved by using the two columns(TSKgel SCX and TSKgel Super IC-A/C connected in series),lower concentrations of PFBA and sulfuric acid as eluents,non-suppressed conductivity detection and UV detection at 210 nm.This analysis was applied to anaerobic digestion process waters.The chromatograms with conductivity detection were relatively simpler compared with those of UV detection.The use of two columns with different selectivities for the aliphatic carboxylic acids and the two detection modes was effective for the determination and identification of the analytes in anaerobic digestion process waters containing complex matrices.
基金Project supported by the National Nartural Science Foundation of China
文摘Activity on catalytic reduction of C<sub>2</sub>H<sub>2</sub> for seven Mo-Fe-S cluster compounds (I. （Et<sub>4</sub>N<sub>4</sub>）<sub>4</sub>[Mo<sub>2</sub>Fe<sub>2</sub>S<sub>10</sub>]·2CH<sub>3</sub>OH, Ⅱ. Mo<sub>2</sub>Fe<sub>2</sub>S<sub>4</sub>（S<sub>2</sub>CNEt<sub>2</sub>）<sub>5</sub>·CH<sub>3</sub>CN, Ⅲ. （Bu<sub>4</sub>N）<sub>3</sub> [Mo<sub>2</sub>FeS<sub>8</sub>O]·Ⅳ·（Et<sub>4</sub>N）<sub>3</sub>[Mo<sub>2</sub>FeS<sub>8</sub>O<sub>2</sub>], V. （Et<sub>4</sub>N）<sub>2</sub>[MoFeS<sub>4</sub>（SCN）<sub>2</sub>（OCH<sub>3</sub>）<sub>2</sub>]·3CH<sub>3</sub>OH, Ⅵ. （Et<sub>4</sub>N）<sub>3</sub>[Mo<sub>2</sub>FeS<sub>8</sub>O（OCH<sub>3</sub>）<sub>2</sub>], Ⅶ. （Et<sub>4</sub>N）<sub>4</sub>Mo<sub>2</sub>Fe<sub>7</sub>S<sub>12</sub>（SPh）<sub>6</sub>·6CH<sub>3</sub>OH), three Fe-S cluster compounds （Ⅷ.（Et<sub>4</sub>N）<sub>2</sub>[Fe<sub>4</sub>S<sub>4</sub>（S<sub>2</sub>CNEt<sub>2</sub>）<sub>4</sub>], Ⅸ. （Bu<sub>4</sub>N）<sub>2</sub>[Fe<sub>4</sub>S<sub>3</sub>（SC（CH<sub>3</sub>）<sub>3</sub>）<sub>4</sub>], Ⅹ. （Bu<sub>4</sub>N）[Fe<sub>2</sub>S<sub>3</sub>（SCH<sub>2</sub>Ph）<sub>2</sub>]） and combination systems of related compounds, has been determined under anaerobic conditions at 25℃ and with KBH<sub>4</sub> as the reductant. In addition, at 15℃, under otherwise the same conditions, activity on catalytic reduction of C<sub>2</sub>H<sub>2</sub> for different constituent systems from （NH<sub>4</sub>）<sub>2</sub>MoS<sub>4</sub> and FeCl<sub>3</sub> has also been determined.
