A cost sensitivity analysis was performed for an industrial membrane bioreactor to quantify the effects of hydraulic retention times and related operational parameters on cost.Different hydraulic retention times(72-24...A cost sensitivity analysis was performed for an industrial membrane bioreactor to quantify the effects of hydraulic retention times and related operational parameters on cost.Different hydraulic retention times(72-24 h)were subjected to a flat-sheet membrane bioreactor updated from an existing 72 h oxidation ditch treating antibiotic production wastewater.Field experimental data from the membrane bioreactor,both full-scale(500 m/d)and pilot(1.0 m3/d),were used to calculate the net present value(NPV),incorporating both capital expenditure(CAPEX)and operating expenditure.The results showed that the tank cost was estimated above membrane cost in the 38.2%,where capital expenditure contributed 24.2%more than operational expenditure.Tank construction cost was decisive in determining the net present value contributed 62.1%to the capital expenditure.The membrane bioreactor has the advantage of a longer lifespan flat-sheet membrane,while flux decline was tolerable.The antibiotics decreased to 1.87±0.33 mg/L in the MBR effluent.The upgrade to the membrane bioreactor also benefited further treatments by 10.1%-44.7%lower direct investment.展开更多
Nanoparticles have been used as diagnostic and therapeutic agents in the human medical field for quite some time, though their application in veterinary medicine and animal production is still relatively new. Recently...Nanoparticles have been used as diagnostic and therapeutic agents in the human medical field for quite some time, though their application in veterinary medicine and animal production is still relatively new. Recently,production demands on the livestock industry have been centered around the use of antibiotics as growth promoters due to growing concern over microbial antibiotic resistance. With many countries reporting increased incidences of antibiotic-resistant bacteria, laws and regulations are being updated to end in-feed antibiotic use in the animal production industry. This sets the need for suitable alternatives to be established for inclusion in feed.Many reports have shown evidence that nanoparticles may be good candidates for animal growth promotion and antimicrobials. The current status and advancements of nanotechnological applications in animal production will be the focus of this review and the emerging roles of nanoparticles for nutrient delivery, biocidal agents, and tools in veterinary medicine and reproduction will be discussed. Additionally, influences on meat, egg, and milk quality will be reviewed.展开更多
Antimicrobials are critical to contemporary high-intensity beef production. Many different antimicrobials are approved for beef cattle, and are used judiciously for animal welfare, and controversially, to promote grow...Antimicrobials are critical to contemporary high-intensity beef production. Many different antimicrobials are approved for beef cattle, and are used judiciously for animal welfare, and controversially, to promote growth and feed efficiency. Antimicrobial administration provides a powerful selective pressure that acts on the microbial community, selecting for resistance gene determinants and antimicrobial-resistant bacteria resident in the bovine flora. The bovine microbiota includes many harmless bacteria, but also opportunistic pathogens that may acquire and propagate resistance genes within the microbial community via horizontal gene transfer. Antimicrobial-resistant bovine pathogens can also complicate the prevention and treatment of infectious diseases in beef feedlots,threatening the efficiency of the beef production system. Likewise, the transmission of antimicrobial resistance genes to bovine-associated human pathogens is a potential public health concern. This review outlines current antimicrobial use practices pertaining to beef production, and explores the frequency of antimicrobial resistance in major bovine pathogens. The effect of antimicrobials on the composition of the bovine microbiota is examined, as are the effects on the beef production resistome. Antimicrobial resistance is further explored within the context of the wider beef production continuum, with emphasis on antimicrobial resistance genes in the food chain, and risk to the human population.展开更多
The pretreatment technology of wet air oxidation(WAO) and coagulation and acidic hydrolysis for apramycin wastewater was investigated in this paper. The COD, apramycin, NH^+_4 concentration, and the ratio of BOD_5/COD...The pretreatment technology of wet air oxidation(WAO) and coagulation and acidic hydrolysis for apramycin wastewater was investigated in this paper. The COD, apramycin, NH^+_4 concentration, and the ratio of BOD_5/COD were analyzed, and the color and odor of the effluent were observed. WAO of apramycin wastewater, without catalyst and with RuO_2/Al_2O_3 and RuO_2-CeO_2/Al_2O_3 catalysts, was carried out at degradation temperature of 200℃ and the total pressure of 4 MPa in a 1 L batch reactor. The result showed that the apramycin removals were respectively 50 2% and 55 0%, COD removals were 40 0% and 46 0%, and the ratio of BOD_5/COD was increased to 0 49 and 0 54 with RuO_2/Al_2O_3 and RuO_2-CeO_2/Al_2O_3 catalysts in catylytic wet air oxidation(CWAO) after the reaction of 150 min. With the pretreatment of coagulation and acidic hydrolysis, COD and apramycin removals were slight decreased, and the ratio of BOD_5/COD was increased to 0 45, and the effluents was not suitable to biological treatment. The color and odor of the wastewater were effectively controlled and the reaction time was obviously shortened with WAO. HO_2· may promote organic compounds oxidized in WAO of the apramycin wastewater. The addition of CeO_2 could promote the activity and stability of RuO_2/Al_2O_3 in WAO of apramycin wastewater.展开更多
A pilot-scale anaerobic ammonia oxidation (ANAMMOX) reactor was used to treat mixed waste- water resulting from a chlortetracycline and starch production process. The results, collected over the course of 272 days, ...A pilot-scale anaerobic ammonia oxidation (ANAMMOX) reactor was used to treat mixed waste- water resulting from a chlortetracycline and starch production process. The results, collected over the course of 272 days, show that the ratio of influent ammonium to nitrite, pH, and temperature can all affect the efficiency of nitrogen removal. The ratio of influent ammonium to nitrite was maintained at about 1:1 at a concentration below 200 mg.L^-1 for both influent ammonium and nitrite. The total nitrogen (TN) loading rate was 0.15- 0.30 kgN.m-3. dq, pH remained at 7.8-8.5, and tempera- ture was recorded at 33±1℃. The rate of removal of ammonia, nitrite, and TN were over 90%, 90%, and 80%, and the effluent ammonium, nitrite and TN concentrations were below 50, 30, and 100mg.Lq.展开更多
基金This work was supported by the National Key Research and Development Program of China(No.2016YFD0501405)National Natural Science Foundation of China(Grant No.21677161)Major Science&Technology Program for Water Pollution Control and Treatment of China(Nos.2017ZX07102-002 and 2018ZX07105-001).
文摘A cost sensitivity analysis was performed for an industrial membrane bioreactor to quantify the effects of hydraulic retention times and related operational parameters on cost.Different hydraulic retention times(72-24 h)were subjected to a flat-sheet membrane bioreactor updated from an existing 72 h oxidation ditch treating antibiotic production wastewater.Field experimental data from the membrane bioreactor,both full-scale(500 m/d)and pilot(1.0 m3/d),were used to calculate the net present value(NPV),incorporating both capital expenditure(CAPEX)and operating expenditure.The results showed that the tank cost was estimated above membrane cost in the 38.2%,where capital expenditure contributed 24.2%more than operational expenditure.Tank construction cost was decisive in determining the net present value contributed 62.1%to the capital expenditure.The membrane bioreactor has the advantage of a longer lifespan flat-sheet membrane,while flux decline was tolerable.The antibiotics decreased to 1.87±0.33 mg/L in the MBR effluent.The upgrade to the membrane bioreactor also benefited further treatments by 10.1%-44.7%lower direct investment.
基金the funding support from Foshan University,Chinathe Natural Sciences and Engineering Research Council of Canada(NSERC)
文摘Nanoparticles have been used as diagnostic and therapeutic agents in the human medical field for quite some time, though their application in veterinary medicine and animal production is still relatively new. Recently,production demands on the livestock industry have been centered around the use of antibiotics as growth promoters due to growing concern over microbial antibiotic resistance. With many countries reporting increased incidences of antibiotic-resistant bacteria, laws and regulations are being updated to end in-feed antibiotic use in the animal production industry. This sets the need for suitable alternatives to be established for inclusion in feed.Many reports have shown evidence that nanoparticles may be good candidates for animal growth promotion and antimicrobials. The current status and advancements of nanotechnological applications in animal production will be the focus of this review and the emerging roles of nanoparticles for nutrient delivery, biocidal agents, and tools in veterinary medicine and reproduction will be discussed. Additionally, influences on meat, egg, and milk quality will be reviewed.
基金supported by an NSERC Postdoctoral Fellowshipsupported by the Beef Cattle Research Council BCRC–Agriculture and Agri-Food Canada beef cluster
文摘Antimicrobials are critical to contemporary high-intensity beef production. Many different antimicrobials are approved for beef cattle, and are used judiciously for animal welfare, and controversially, to promote growth and feed efficiency. Antimicrobial administration provides a powerful selective pressure that acts on the microbial community, selecting for resistance gene determinants and antimicrobial-resistant bacteria resident in the bovine flora. The bovine microbiota includes many harmless bacteria, but also opportunistic pathogens that may acquire and propagate resistance genes within the microbial community via horizontal gene transfer. Antimicrobial-resistant bovine pathogens can also complicate the prevention and treatment of infectious diseases in beef feedlots,threatening the efficiency of the beef production system. Likewise, the transmission of antimicrobial resistance genes to bovine-associated human pathogens is a potential public health concern. This review outlines current antimicrobial use practices pertaining to beef production, and explores the frequency of antimicrobial resistance in major bovine pathogens. The effect of antimicrobials on the composition of the bovine microbiota is examined, as are the effects on the beef production resistome. Antimicrobial resistance is further explored within the context of the wider beef production continuum, with emphasis on antimicrobial resistance genes in the food chain, and risk to the human population.
文摘The pretreatment technology of wet air oxidation(WAO) and coagulation and acidic hydrolysis for apramycin wastewater was investigated in this paper. The COD, apramycin, NH^+_4 concentration, and the ratio of BOD_5/COD were analyzed, and the color and odor of the effluent were observed. WAO of apramycin wastewater, without catalyst and with RuO_2/Al_2O_3 and RuO_2-CeO_2/Al_2O_3 catalysts, was carried out at degradation temperature of 200℃ and the total pressure of 4 MPa in a 1 L batch reactor. The result showed that the apramycin removals were respectively 50 2% and 55 0%, COD removals were 40 0% and 46 0%, and the ratio of BOD_5/COD was increased to 0 49 and 0 54 with RuO_2/Al_2O_3 and RuO_2-CeO_2/Al_2O_3 catalysts in catylytic wet air oxidation(CWAO) after the reaction of 150 min. With the pretreatment of coagulation and acidic hydrolysis, COD and apramycin removals were slight decreased, and the ratio of BOD_5/COD was increased to 0 45, and the effluents was not suitable to biological treatment. The color and odor of the wastewater were effectively controlled and the reaction time was obviously shortened with WAO. HO_2· may promote organic compounds oxidized in WAO of the apramycin wastewater. The addition of CeO_2 could promote the activity and stability of RuO_2/Al_2O_3 in WAO of apramycin wastewater.
文摘A pilot-scale anaerobic ammonia oxidation (ANAMMOX) reactor was used to treat mixed waste- water resulting from a chlortetracycline and starch production process. The results, collected over the course of 272 days, show that the ratio of influent ammonium to nitrite, pH, and temperature can all affect the efficiency of nitrogen removal. The ratio of influent ammonium to nitrite was maintained at about 1:1 at a concentration below 200 mg.L^-1 for both influent ammonium and nitrite. The total nitrogen (TN) loading rate was 0.15- 0.30 kgN.m-3. dq, pH remained at 7.8-8.5, and tempera- ture was recorded at 33±1℃. The rate of removal of ammonia, nitrite, and TN were over 90%, 90%, and 80%, and the effluent ammonium, nitrite and TN concentrations were below 50, 30, and 100mg.Lq.