Recovery of caprolactam from waste water of caprolactam production factory was investigated using benzene as solvent in a small-scale pulsed-sieve-plate column. First, liquid-liquid equilibrium (LLE) data were measure...Recovery of caprolactam from waste water of caprolactam production factory was investigated using benzene as solvent in a small-scale pulsed-sieve-plate column. First, liquid-liquid equilibrium (LLE) data were measured, including water-caprolactam-benzene system at low caprolactam concentrations, and waste water-benzene system. Then, the operating regions and mass transfer of the pulsed-sieve-plate column were measured. Finally, the overall apparent heights of a transfer unit based on continuous phase are correlated in terms of the column operation variables.展开更多
The work described here was focused on exploring the potential application of coal to purification of oily waste water.Coal was added to oily waste water as an adsorbent and then removed through a flotation process.Th...The work described here was focused on exploring the potential application of coal to purification of oily waste water.Coal was added to oily waste water as an adsorbent and then removed through a flotation process.This allowed economical and highly efficient separation of oil from the waste water.The absorption time,coal type,coal particle size distribution,pH value and oil concentration were investigated.The results indicate that oil absorption by a coal increases for a period of 1.5 h and then gradually tends toward an equilibrium value.It appears that the absorption capacity of anthracite is more than that of lean coal or lignite,given the same coal particle size distribution.The absorption capacity of a coarse coal fraction is less than that of finer coal,given the same of coal type.The absorption capacity of anthracite decreases slightly as the pH increases from 4 to 9.The adsorption of oil on anthracite follows the Freundlich isothermal adsorption law:given initial oil concentrations of 160.5 or 1023.6 mg/L the absorption capacity was 23.8 or 840.0 mg/g.The absorption mechanism consists of two kinds of absorption,a physical process assisted by a chemical one.展开更多
In this work,the effects of pH value of waste water and initial concentration of phosphorus on dephosphorization materials were investigated.The materials were prepared by shaping,sintering and hydrothermal reshaping ...In this work,the effects of pH value of waste water and initial concentration of phosphorus on dephosphorization materials were investigated.The materials were prepared by shaping,sintering and hydrothermal reshaping oyster shell and silica micro-powder.Different concentrations of phosphorus-contained waste water were simulated with potassium dihydrogen phosphate solution,the effect of dephosphorization was tested with phosphomolybdenum blue spectrophotometer method,and the crystal phase and microstructure of materials were characterized by XRD and SEM methods. It was indicated that dephosphorization was completed in 6 h when the initial phosphorus concentration in waste water was lower than 15 mg/L, and the dephosphorization time prolonged as the increase of phosphorus concentration. It was observed that the pH value of waste water influenced dephosphorization significantly, and neutral subalkalic environment favored dephosphorization. When the pH value was 11, the efficiency of dephosphozation was the greatest. For waste water with an initial concentration of 20 mg/L, the dephosphozation rate is close to 100% in8 h.展开更多
A waste water reuse engineering was designed and then operated in Hongshan, a small town in ZhejiangProvince, China, in order to solve pollution and shortage of water resources due to the development of ruralenterpris...A waste water reuse engineering was designed and then operated in Hongshan, a small town in ZhejiangProvince, China, in order to solve pollution and shortage of water resources due to the development of ruralenterprises. The results showed that series-structure design and cycling model were two effective modes ofsaving water and decreasing pollutants into environment, and wetland strategy should be a component partof the integrated planning for waste water reuse of rural enterprises. This case study could provide a basisfor the optimum utilization and pollution avoidance of water resources.展开更多
In this experiment the performance of UBF process treatment for wastewater chicken manure was tested under the condition of constant temperature of 35℃ and the volume of UBF is 4 liters. The experiment covered two s...In this experiment the performance of UBF process treatment for wastewater chicken manure was tested under the condition of constant temperature of 35℃ and the volume of UBF is 4 liters. The experiment covered two stages: the first was start up with phase I and phase II, the second was steady state. The following results average of operation period were obtained: (1) During the period of start up phase I operation the biogas production rate 0.39v/(v.day) at the volumetric COD loading rate of 2.97 kg COD/(m 3.d) with COD removal 76.85% and hydraulic retention time of 10.04 hours and phase II the biogas production rate 3.86 v/(v.day) at the volume loading rate 11.69 kg COD/(m 3.d) have been achieved with COD removal 82.47% and HRT 16.45 hours. UBF process had resistance to the quantitative shock load. (2) During the steady state operation, the biogas production rate 9.83v/(v.day) at loading rate of 28.85 kg COD/(m 3.d) and COD removal efficiency 80.03% and hydraulic retention time of 18.73 hours have been achieved for this reactor. The operation of UBF reactor was very stable.展开更多
The waste water system generated in the process of production of cuprous chloride was studied.The existing forms of copper in the system and the influence of temperature and pH on the existing forms of copper ion were...The waste water system generated in the process of production of cuprous chloride was studied.The existing forms of copper in the system and the influence of temperature and pH on the existing forms of copper ion were analyzed and determined through calculating the coefficients of copper complex distribution.In the waste water system,the main forms of copper are CuSO4, Cu2 +,CuCl + ,CuCl, 2-and2- 3 CuCl.Temperature has little influence on the distribution coefficient of Cu(Ⅱ),but has significant influence on distribution coefficient of Cu(Ⅰ).With the increase of temperature,the distribution coefficient ofCuCl, 2-increases significantly while the distribution coefficient of2- 3 CuCl decreases.The pH has nearly no influence on the distribution coefficients of various Cu(Ⅰ)-compounds,but has sizable influence on the distribution coefficients of Cu(Ⅱ)-compounds.With the increase of pH,the distribution coefficient of CuSO4(aq)increases while the distribution coefficients of Cu 2+ and CuCl + decrease.According to these results,the anion resin of 201×7 OH-and the cation resin of 732 Na were chosen to dispose the waste water solution of cuprous chloride.Finally,97.9%copper in the waste water is recovered.展开更多
Porous haydite used as waste filter medium was prepared by dreging lake sludge to help solve the treatment problem of sludge and realize its reclamation. Several calcination regimes were considered and their effects o...Porous haydite used as waste filter medium was prepared by dreging lake sludge to help solve the treatment problem of sludge and realize its reclamation. Several calcination regimes were considered and their effects on the pore structure and the properties such as the strength, the density, the filtering ability and the phosphate absorption ability of the haydite were investigated, For the mixture of 60% lake sludge and 40% fly ash in this experiment, the calcination regime with a pre-caleination period at about 600℃, a temperature keeping period at 1 200 ℃ and a moderate cooling rate are recommended to prepare haydite with reasonable pore structure and good performances for its usage as the waste water filter media.展开更多
The paper described the coking plant and Lurgi gasifier plant waste water types and characteristics , comparing the COD and ammonia-N level in different source of waste water in the plant.The currently maturity coking...The paper described the coking plant and Lurgi gasifier plant waste water types and characteristics , comparing the COD and ammonia-N level in different source of waste water in the plant.The currently maturity coking plant waste water treatment method was statement in the paper and analyzed the pros and cons of each method.The primary cost analysis of each type of waste water treatment was also completed in the paper.According to these analyses , recommendation was prepared for coking plant and Lurgi gasifier plant waste water treatment.展开更多
The electrochemical oxidation of chlorimuron-ethyl on metry. The electrochemical behaviour of the electrode in a sodium Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltamsulfate solution and in the mixture solu...The electrochemical oxidation of chlorimuron-ethyl on metry. The electrochemical behaviour of the electrode in a sodium Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltamsulfate solution and in the mixture solution of sodium sulfate and chlorimuron-ethyl was studied. The experimental results of cyclic voltammetry show that the acidic medium was suitable for the efficient electrochemical oxidation of chlorimuron-ethyl. Some electro-generated reagent was formed in the electrolysis process and chlorimuron-ethyl could be oxidized by the electro-generated reagent. A Ti/SnO2-Sb2O5/PbO2 electrode was used as the anode and the electrolysis experiment was carried out under the optimized conditions. The electrolysis process was monitored by UV-Vis spectrometry and high performance liquid chromatography(HPLC), and the chemical oxygen demand(COD) was determined by the potassium dichromate method. The mechanism of chlorimuron-ethyl to be oxided was studied primarily by the cyclic voltammetry and UV-Vis spectrometry. The results of electrolysis experiment demonstrate the possibility of the electrode to be used as an anode for the electrochemical treatment of chlorimuron-ethyl contained in waste water.展开更多
Oyster shell and cement were taken as the major raw materials to fabricate hollow, tubular and recoverable material for phosphorous removal (P removal) from waste water without sintering. In this paper, the effects ...Oyster shell and cement were taken as the major raw materials to fabricate hollow, tubular and recoverable material for phosphorous removal (P removal) from waste water without sintering. In this paper, the effects of different affecting factors on the sample P removal ratio were discussed to select optimal P removal process conditions. SEM and XRD were used to characterize the microscopic structures and composition of samples, and molybdenum blue spectrophotometry was applied to determine the P content in waste water. Results showed that at 30 ℃ for 2 d, the P removal ratio reached 93.3% when the cement content was 10 wt% and oyster shell powder was 90 wt%. SEM analysis revealed a flaky structure consisting of phosphorus-containing compound in the samples after P removal, and it piled on and maintained the porous structure. In addition, the results also suggested that raising the ambient temperature was benefit to the P removal. The P removal ratio of the material was optimal under neutral and alkali conditions.展开更多
Since COVID-19 was declared by the World Health Organization (WHO), wearing of protective equipment, hand washing using soap and frequent use of antiseptic solution are being applied globally to reduce the transmissio...Since COVID-19 was declared by the World Health Organization (WHO), wearing of protective equipment, hand washing using soap and frequent use of antiseptic solution are being applied globally to reduce the transmission rate. This study was intended to investigate handling of after wash waste water and masks among Tanzanian residents on the COVID-19 pandemic after it has been, declared by the World Health Organization (WHO) that, wearing of protective equipment, hand washing using soap and frequent use of antiseptic solution should be applied globally to reduce the transmission rate. The assessment of health care waste management in the facilities was conducted in all the 26 regions of Tanzania Mainland. A standardized checklist and tools were used to assess and monitor various aspects related to healthcare waste using open source software for collection (ODK). Data were analyzed using SPSS computer software. It has been indicated that before disposing the used mask, the best protocol is to spray 0.5% (5000 ppm) of chlorine disinfectant on the surface. In this study, about 46% consider used mask as normal municipal waste and 3% do not care they throw away the face masks in the street. Only 18% and 5% of reported to disposal as infectious and highly hazardous waste respectively. It is well documented that due to potential infectious disease like SARS-CoV-2, wastewater should be treated either on-site or conveyed off-site and treated in well-designed method or technology to kill the micro-organisms. The analysis revealed that majority of respondents (74.7%, 73.8%, 48.1% and 65% for healthcare center, district hospitals, regional hospitals and consultant hospitals respectively);dispose the waste in the open space. Continuous awareness creation programs about the negative impact of contaminated face masks and waste water on the health of individuals and introducing laws that can prohibit improper disposal are among the solutions that could help reduce the problem.展开更多
The olive mill waste waters (OMWW) generated from olive oil extraction is a major environmental concern since they are characterized by their role as a pollutant (high organic and mineral matters) and their pH acid. T...The olive mill waste waters (OMWW) generated from olive oil extraction is a major environmental concern since they are characterized by their role as a pollutant (high organic and mineral matters) and their pH acid. The aim of this study was to valorize (OMWW) by anaerobic fermentation in the presence of cow manure in order to produce biogas and reduce their toxic load. Many tests were carried out by fermenting (OMWW) with polyphenols in the presence of cow manure in thermophile temperatures. The performance of this treatment was valuated through measurements of biogas production and by the determination of different parameters of fermented media (pH, volume of the biogas and polyphenols).展开更多
The aim of this work is to assess the short term effect of OMWW (olive mill waste water) application on chemical and biological soil properties. A field experiment was carried out in southern Tunisia. OMWW applicati...The aim of this work is to assess the short term effect of OMWW (olive mill waste water) application on chemical and biological soil properties. A field experiment was carried out in southern Tunisia. OMWW application was done at rates equivalent to 0, 15, 30 and 45 m^3/ha. Results showed that increasing rates of OMWW enhance the soil fertility due to its richness in organic matter such as N and P. A rapid increase of microbial biomass (during 14 days of incubation) of OMWW amended soils occurred. However, a high increase in salinity values and phenolic compounds concentrations was observed during this experiment.展开更多
The influences of kinds and level of catalyst, time of decomposition reaction on the distribution of dibasic acid and apparent yield of adipic acid were researched; the acidic washing waste water (BI waste water) pr...The influences of kinds and level of catalyst, time of decomposition reaction on the distribution of dibasic acid and apparent yield of adipic acid were researched; the acidic washing waste water (BI waste water) producing from the equipment of cyclohexane oxidation by air was as stuff, the component of products by decomposed and oxidated in different conditions were analysed. It indicated that in the presence of cobalt salt the apparent yield of adipic acid was upto 10%-12% for the total BI waste water after the concentrated BI waste water refluxed for two hours, and then oxidated by nitric acid.展开更多
Untreated Hospital wastewater piped into septic tanks contributes to the spread of antibiotic resistance in developing countries. This study was conducted to determine the resistant profile, and Extended Spectrum Beta...Untreated Hospital wastewater piped into septic tanks contributes to the spread of antibiotic resistance in developing countries. This study was conducted to determine the resistant profile, and Extended Spectrum Beta-Lactamases (ESBLs) production in isolates from hospital waste water, of 2 hospitals in Delta State, Nigeria. A total of 147 organisms were isolated from 32 waste water samples. One hundred and twenty three isolates were Gram negative and 24 were Gram positive. Escherichia coli was the most prevalent in the two locations. Antimicrobial susceptibility by standard disk diffusion method was performed. All isolates were resistant to 4 or more antimicrobial agents. Out of the 123 Gram negative Bacteria, 33 were pan drug resistant and were selected for plasmid curing, DNA extraction and phenotypic detection of ESBL. Transfer of resistant by broth mating technique was performed. Plasmid curing and extraction result indicated that isolates carried resistance on the plasmid and harboured similar multiple high molecular weight plasmids of 23.13 kb and 9.4 kb. ESBL production was detected in 15.15%. Transfer of resistant genes between ESBL producing and non-ESBL producing isolates was observed. Incidence of ESBL in untreated hospital waste water has public health implications. Therefore establishment of treatment plants in our hospital is paramount in achieving sustainable health.展开更多
The most of iron, cement, paper and plastic related industries are running in Raipur area of the country. They use a large amount of water by discharging effluents into the streams and rivers by polluting nearby water...The most of iron, cement, paper and plastic related industries are running in Raipur area of the country. They use a large amount of water by discharging effluents into the streams and rivers by polluting nearby water resources. In this work, the physico-chemical characteristics of discharged waste water of 34 industries (i.e. iron, steel, power, paper and polymer) are described. The waste water is found to be acidic in nature with high contents of F- and other ions.展开更多
The present study aimed at isolation characterization and evaluation of electrogenic bacteria for electricity generation using waste water. In this context, waste water samples were collected from University of Nizwa ...The present study aimed at isolation characterization and evaluation of electrogenic bacteria for electricity generation using waste water. In this context, waste water samples were collected from University of Nizwa waste water treatment plant. A total of eight distinct bacterial isolates were isolated from these samples by serial dilution and plating on LB Agar medium. The bacterial isolates were than grown at different temperatures and pH. DNA from bacterial samples was isolated and 16S rRNA gene amplification was carried out. The 16S rRNA gene PCR products were directly sequenced and the resulting sequence was blasted using BLASTn. Based on BLAST results, the bacterial strains were identified. The bacteria were used in different combinations to generate electricity from waste water in microbial fuel cells constructed using plastic bottles. The microbial isolates were found to produce varying levels of currents and their electrogenic potential in waste water was observed to increase with the passage of time.展开更多
Electroplating waste water is considered to be harmful to health of animals. In the present study, we tested the hypothesis that electroplating waste water would suppress immune functions in Kunming mice. Twenty-six m...Electroplating waste water is considered to be harmful to health of animals. In the present study, we tested the hypothesis that electroplating waste water would suppress immune functions in Kunming mice. Twenty-six mice were randomly divided into the control group (n = 13) and the experimental group (n = 13), in which the latter drank electroplating waste water. We found that body mass and most organ wet masses (heart, lungs, liver, kidneys, stomach, caecum, colon, testes, epididymis, seminal vesicals) were not influenced by electroplating waste water. However, stomach with its content, small intestine, small intestine with its contents and colon with its contents were higher in the experimental group than in the control group. As expected, phytohaemagglutinin (PHA) response indicative of cellular immunity was suppressed by electroplating waste water. White blood cells, thymus and spleen mass were all not response to electroplating waste water. Taken together, electroplating waste water had different effects on distinct components of immune system in Kunming mice.展开更多
The percent ammonia nitrogen was determined in Passaic River waste water using Ion-Selective Electrode EPA Method 350.3. The intelligent ammonia sensor integrates ammonia electrode, pH electrode and Ammonia Ion electr...The percent ammonia nitrogen was determined in Passaic River waste water using Ion-Selective Electrode EPA Method 350.3. The intelligent ammonia sensor integrates ammonia electrode, pH electrode and Ammonia Ion electrode together to realize the in situ detection of ammonia. The test results have shown that the sensor is easy operation, low cost and no pollution. The ammonia is determined potentiometrically using an ammonia ion selective electrode and a pH/mV meter, having an expanded millivolt scale. The ammonia selective electrode uses a hydrophobic gas-permeable membrane to separate the sample solution from an electrode internal solution of ammonium chloride. Dissolved ammonia is converted to NH<sub>3</sub> gas by raising the pH to above 11.0 with a strong base. NH<sub>3</sub> gas diffuses the membrane and changes the internal solution pH that is sensed by the electrode. In single laboratory test results have been found 1.001 NH<sub>3</sub>-/L and 0.897 mg NH<sub>3</sub>-N/L, recoveries were 77.3% and 83.1%, respectively.展开更多
基金Partly supported by UK's Academic Link with China Scheme (ALCS: SHA/992/307), British Council.
文摘Recovery of caprolactam from waste water of caprolactam production factory was investigated using benzene as solvent in a small-scale pulsed-sieve-plate column. First, liquid-liquid equilibrium (LLE) data were measured, including water-caprolactam-benzene system at low caprolactam concentrations, and waste water-benzene system. Then, the operating regions and mass transfer of the pulsed-sieve-plate column were measured. Finally, the overall apparent heights of a transfer unit based on continuous phase are correlated in terms of the column operation variables.
基金the Science and Technology Fund of China University of Mining & Technology (No.2006A019)the National Natural Science Foundation of China (No.50974119) for their support of this project
文摘The work described here was focused on exploring the potential application of coal to purification of oily waste water.Coal was added to oily waste water as an adsorbent and then removed through a flotation process.This allowed economical and highly efficient separation of oil from the waste water.The absorption time,coal type,coal particle size distribution,pH value and oil concentration were investigated.The results indicate that oil absorption by a coal increases for a period of 1.5 h and then gradually tends toward an equilibrium value.It appears that the absorption capacity of anthracite is more than that of lean coal or lignite,given the same coal particle size distribution.The absorption capacity of a coarse coal fraction is less than that of finer coal,given the same of coal type.The absorption capacity of anthracite decreases slightly as the pH increases from 4 to 9.The adsorption of oil on anthracite follows the Freundlich isothermal adsorption law:given initial oil concentrations of 160.5 or 1023.6 mg/L the absorption capacity was 23.8 or 840.0 mg/g.The absorption mechanism consists of two kinds of absorption,a physical process assisted by a chemical one.
基金Supported by Fujian Science and Technology Administration (2004I003 and 20060037)
文摘In this work,the effects of pH value of waste water and initial concentration of phosphorus on dephosphorization materials were investigated.The materials were prepared by shaping,sintering and hydrothermal reshaping oyster shell and silica micro-powder.Different concentrations of phosphorus-contained waste water were simulated with potassium dihydrogen phosphate solution,the effect of dephosphorization was tested with phosphomolybdenum blue spectrophotometer method,and the crystal phase and microstructure of materials were characterized by XRD and SEM methods. It was indicated that dephosphorization was completed in 6 h when the initial phosphorus concentration in waste water was lower than 15 mg/L, and the dephosphorization time prolonged as the increase of phosphorus concentration. It was observed that the pH value of waste water influenced dephosphorization significantly, and neutral subalkalic environment favored dephosphorization. When the pH value was 11, the efficiency of dephosphozation was the greatest. For waste water with an initial concentration of 20 mg/L, the dephosphozation rate is close to 100% in8 h.
文摘A waste water reuse engineering was designed and then operated in Hongshan, a small town in ZhejiangProvince, China, in order to solve pollution and shortage of water resources due to the development of ruralenterprises. The results showed that series-structure design and cycling model were two effective modes ofsaving water and decreasing pollutants into environment, and wetland strategy should be a component partof the integrated planning for waste water reuse of rural enterprises. This case study could provide a basisfor the optimum utilization and pollution avoidance of water resources.
文摘In this experiment the performance of UBF process treatment for wastewater chicken manure was tested under the condition of constant temperature of 35℃ and the volume of UBF is 4 liters. The experiment covered two stages: the first was start up with phase I and phase II, the second was steady state. The following results average of operation period were obtained: (1) During the period of start up phase I operation the biogas production rate 0.39v/(v.day) at the volumetric COD loading rate of 2.97 kg COD/(m 3.d) with COD removal 76.85% and hydraulic retention time of 10.04 hours and phase II the biogas production rate 3.86 v/(v.day) at the volume loading rate 11.69 kg COD/(m 3.d) have been achieved with COD removal 82.47% and HRT 16.45 hours. UBF process had resistance to the quantitative shock load. (2) During the steady state operation, the biogas production rate 9.83v/(v.day) at loading rate of 28.85 kg COD/(m 3.d) and COD removal efficiency 80.03% and hydraulic retention time of 18.73 hours have been achieved for this reactor. The operation of UBF reactor was very stable.
基金Projects(5087408750978212)supported by the National Natural Science Foundation of China+1 种基金Project(2006E106)supported by Natural Science Foundation of Shaanxi Province,ChinaProject(07JK302)supported by Special Natural Science Foundation of Shaanxi Province Education Office,China
文摘The waste water system generated in the process of production of cuprous chloride was studied.The existing forms of copper in the system and the influence of temperature and pH on the existing forms of copper ion were analyzed and determined through calculating the coefficients of copper complex distribution.In the waste water system,the main forms of copper are CuSO4, Cu2 +,CuCl + ,CuCl, 2-and2- 3 CuCl.Temperature has little influence on the distribution coefficient of Cu(Ⅱ),but has significant influence on distribution coefficient of Cu(Ⅰ).With the increase of temperature,the distribution coefficient ofCuCl, 2-increases significantly while the distribution coefficient of2- 3 CuCl decreases.The pH has nearly no influence on the distribution coefficients of various Cu(Ⅰ)-compounds,but has sizable influence on the distribution coefficients of Cu(Ⅱ)-compounds.With the increase of pH,the distribution coefficient of CuSO4(aq)increases while the distribution coefficients of Cu 2+ and CuCl + decrease.According to these results,the anion resin of 201×7 OH-and the cation resin of 732 Na were chosen to dispose the waste water solution of cuprous chloride.Finally,97.9%copper in the waste water is recovered.
基金Funded by the Fundamental Research Funds for the Central Universities(No.2011-IV-010)the National Natural Science Foundation of China(No.50902106)the Program for New Century Excellent Talents in University of China(No.NCET-10-0660)
文摘Porous haydite used as waste filter medium was prepared by dreging lake sludge to help solve the treatment problem of sludge and realize its reclamation. Several calcination regimes were considered and their effects on the pore structure and the properties such as the strength, the density, the filtering ability and the phosphate absorption ability of the haydite were investigated, For the mixture of 60% lake sludge and 40% fly ash in this experiment, the calcination regime with a pre-caleination period at about 600℃, a temperature keeping period at 1 200 ℃ and a moderate cooling rate are recommended to prepare haydite with reasonable pore structure and good performances for its usage as the waste water filter media.
文摘The paper described the coking plant and Lurgi gasifier plant waste water types and characteristics , comparing the COD and ammonia-N level in different source of waste water in the plant.The currently maturity coking plant waste water treatment method was statement in the paper and analyzed the pros and cons of each method.The primary cost analysis of each type of waste water treatment was also completed in the paper.According to these analyses , recommendation was prepared for coking plant and Lurgi gasifier plant waste water treatment.
基金Supported by the Science and Technology Foundation of the Education Department of Liaoning Province,China (No.2009A557)
文摘The electrochemical oxidation of chlorimuron-ethyl on metry. The electrochemical behaviour of the electrode in a sodium Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltamsulfate solution and in the mixture solution of sodium sulfate and chlorimuron-ethyl was studied. The experimental results of cyclic voltammetry show that the acidic medium was suitable for the efficient electrochemical oxidation of chlorimuron-ethyl. Some electro-generated reagent was formed in the electrolysis process and chlorimuron-ethyl could be oxidized by the electro-generated reagent. A Ti/SnO2-Sb2O5/PbO2 electrode was used as the anode and the electrolysis experiment was carried out under the optimized conditions. The electrolysis process was monitored by UV-Vis spectrometry and high performance liquid chromatography(HPLC), and the chemical oxygen demand(COD) was determined by the potassium dichromate method. The mechanism of chlorimuron-ethyl to be oxided was studied primarily by the cyclic voltammetry and UV-Vis spectrometry. The results of electrolysis experiment demonstrate the possibility of the electrode to be used as an anode for the electrochemical treatment of chlorimuron-ethyl contained in waste water.
基金Sponsored by the 2007 Fujian University and College New Century Excellent Talent Support Program (No. XSJRC2007-17)Natural Science Foundation of Fujian Province of China(No. 2010J01279)
文摘Oyster shell and cement were taken as the major raw materials to fabricate hollow, tubular and recoverable material for phosphorous removal (P removal) from waste water without sintering. In this paper, the effects of different affecting factors on the sample P removal ratio were discussed to select optimal P removal process conditions. SEM and XRD were used to characterize the microscopic structures and composition of samples, and molybdenum blue spectrophotometry was applied to determine the P content in waste water. Results showed that at 30 ℃ for 2 d, the P removal ratio reached 93.3% when the cement content was 10 wt% and oyster shell powder was 90 wt%. SEM analysis revealed a flaky structure consisting of phosphorus-containing compound in the samples after P removal, and it piled on and maintained the porous structure. In addition, the results also suggested that raising the ambient temperature was benefit to the P removal. The P removal ratio of the material was optimal under neutral and alkali conditions.
文摘Since COVID-19 was declared by the World Health Organization (WHO), wearing of protective equipment, hand washing using soap and frequent use of antiseptic solution are being applied globally to reduce the transmission rate. This study was intended to investigate handling of after wash waste water and masks among Tanzanian residents on the COVID-19 pandemic after it has been, declared by the World Health Organization (WHO) that, wearing of protective equipment, hand washing using soap and frequent use of antiseptic solution should be applied globally to reduce the transmission rate. The assessment of health care waste management in the facilities was conducted in all the 26 regions of Tanzania Mainland. A standardized checklist and tools were used to assess and monitor various aspects related to healthcare waste using open source software for collection (ODK). Data were analyzed using SPSS computer software. It has been indicated that before disposing the used mask, the best protocol is to spray 0.5% (5000 ppm) of chlorine disinfectant on the surface. In this study, about 46% consider used mask as normal municipal waste and 3% do not care they throw away the face masks in the street. Only 18% and 5% of reported to disposal as infectious and highly hazardous waste respectively. It is well documented that due to potential infectious disease like SARS-CoV-2, wastewater should be treated either on-site or conveyed off-site and treated in well-designed method or technology to kill the micro-organisms. The analysis revealed that majority of respondents (74.7%, 73.8%, 48.1% and 65% for healthcare center, district hospitals, regional hospitals and consultant hospitals respectively);dispose the waste in the open space. Continuous awareness creation programs about the negative impact of contaminated face masks and waste water on the health of individuals and introducing laws that can prohibit improper disposal are among the solutions that could help reduce the problem.
文摘The olive mill waste waters (OMWW) generated from olive oil extraction is a major environmental concern since they are characterized by their role as a pollutant (high organic and mineral matters) and their pH acid. The aim of this study was to valorize (OMWW) by anaerobic fermentation in the presence of cow manure in order to produce biogas and reduce their toxic load. Many tests were carried out by fermenting (OMWW) with polyphenols in the presence of cow manure in thermophile temperatures. The performance of this treatment was valuated through measurements of biogas production and by the determination of different parameters of fermented media (pH, volume of the biogas and polyphenols).
文摘The aim of this work is to assess the short term effect of OMWW (olive mill waste water) application on chemical and biological soil properties. A field experiment was carried out in southern Tunisia. OMWW application was done at rates equivalent to 0, 15, 30 and 45 m^3/ha. Results showed that increasing rates of OMWW enhance the soil fertility due to its richness in organic matter such as N and P. A rapid increase of microbial biomass (during 14 days of incubation) of OMWW amended soils occurred. However, a high increase in salinity values and phenolic compounds concentrations was observed during this experiment.
文摘The influences of kinds and level of catalyst, time of decomposition reaction on the distribution of dibasic acid and apparent yield of adipic acid were researched; the acidic washing waste water (BI waste water) producing from the equipment of cyclohexane oxidation by air was as stuff, the component of products by decomposed and oxidated in different conditions were analysed. It indicated that in the presence of cobalt salt the apparent yield of adipic acid was upto 10%-12% for the total BI waste water after the concentrated BI waste water refluxed for two hours, and then oxidated by nitric acid.
文摘Untreated Hospital wastewater piped into septic tanks contributes to the spread of antibiotic resistance in developing countries. This study was conducted to determine the resistant profile, and Extended Spectrum Beta-Lactamases (ESBLs) production in isolates from hospital waste water, of 2 hospitals in Delta State, Nigeria. A total of 147 organisms were isolated from 32 waste water samples. One hundred and twenty three isolates were Gram negative and 24 were Gram positive. Escherichia coli was the most prevalent in the two locations. Antimicrobial susceptibility by standard disk diffusion method was performed. All isolates were resistant to 4 or more antimicrobial agents. Out of the 123 Gram negative Bacteria, 33 were pan drug resistant and were selected for plasmid curing, DNA extraction and phenotypic detection of ESBL. Transfer of resistant by broth mating technique was performed. Plasmid curing and extraction result indicated that isolates carried resistance on the plasmid and harboured similar multiple high molecular weight plasmids of 23.13 kb and 9.4 kb. ESBL production was detected in 15.15%. Transfer of resistant genes between ESBL producing and non-ESBL producing isolates was observed. Incidence of ESBL in untreated hospital waste water has public health implications. Therefore establishment of treatment plants in our hospital is paramount in achieving sustainable health.
文摘The most of iron, cement, paper and plastic related industries are running in Raipur area of the country. They use a large amount of water by discharging effluents into the streams and rivers by polluting nearby water resources. In this work, the physico-chemical characteristics of discharged waste water of 34 industries (i.e. iron, steel, power, paper and polymer) are described. The waste water is found to be acidic in nature with high contents of F- and other ions.
文摘The present study aimed at isolation characterization and evaluation of electrogenic bacteria for electricity generation using waste water. In this context, waste water samples were collected from University of Nizwa waste water treatment plant. A total of eight distinct bacterial isolates were isolated from these samples by serial dilution and plating on LB Agar medium. The bacterial isolates were than grown at different temperatures and pH. DNA from bacterial samples was isolated and 16S rRNA gene amplification was carried out. The 16S rRNA gene PCR products were directly sequenced and the resulting sequence was blasted using BLASTn. Based on BLAST results, the bacterial strains were identified. The bacteria were used in different combinations to generate electricity from waste water in microbial fuel cells constructed using plastic bottles. The microbial isolates were found to produce varying levels of currents and their electrogenic potential in waste water was observed to increase with the passage of time.
文摘Electroplating waste water is considered to be harmful to health of animals. In the present study, we tested the hypothesis that electroplating waste water would suppress immune functions in Kunming mice. Twenty-six mice were randomly divided into the control group (n = 13) and the experimental group (n = 13), in which the latter drank electroplating waste water. We found that body mass and most organ wet masses (heart, lungs, liver, kidneys, stomach, caecum, colon, testes, epididymis, seminal vesicals) were not influenced by electroplating waste water. However, stomach with its content, small intestine, small intestine with its contents and colon with its contents were higher in the experimental group than in the control group. As expected, phytohaemagglutinin (PHA) response indicative of cellular immunity was suppressed by electroplating waste water. White blood cells, thymus and spleen mass were all not response to electroplating waste water. Taken together, electroplating waste water had different effects on distinct components of immune system in Kunming mice.
文摘The percent ammonia nitrogen was determined in Passaic River waste water using Ion-Selective Electrode EPA Method 350.3. The intelligent ammonia sensor integrates ammonia electrode, pH electrode and Ammonia Ion electrode together to realize the in situ detection of ammonia. The test results have shown that the sensor is easy operation, low cost and no pollution. The ammonia is determined potentiometrically using an ammonia ion selective electrode and a pH/mV meter, having an expanded millivolt scale. The ammonia selective electrode uses a hydrophobic gas-permeable membrane to separate the sample solution from an electrode internal solution of ammonium chloride. Dissolved ammonia is converted to NH<sub>3</sub> gas by raising the pH to above 11.0 with a strong base. NH<sub>3</sub> gas diffuses the membrane and changes the internal solution pH that is sensed by the electrode. In single laboratory test results have been found 1.001 NH<sub>3</sub>-/L and 0.897 mg NH<sub>3</sub>-N/L, recoveries were 77.3% and 83.1%, respectively.