An old automotive industrial site located at Mexico City with many years of operation and contaminated with heavy oil hydrocarbons, particularly spent oils, was assessed for restoration using the surfactant enhanced s...An old automotive industrial site located at Mexico City with many years of operation and contaminated with heavy oil hydrocarbons, particularly spent oils, was assessed for restoration using the surfactant enhanced soil washing (SESW) process. The main goal of this study was to characterize the contaminated soil in terms of TPHs, BTEX, PAHs, and metals contents as well as microbiologically (total heterotrophs and specific degrading microorganisms). We also aimed to determine the surfactant type and concentration to be used in the SESW process for the automotive waste oil contaminated soil. At the end, sixteen kg of contaminated soil were washed and the produced wastewater (approximately 40 L) was characterized in terms of COD, BOD;solids, and other physico-chemical parameters. The soil contained about 14,000 mg of TPH/kg soil (heavy fraction), 0.13 mg/kg of benzo (k) fluoranthene and 0.07 mg/kg of benzo (a) pyrene as well as traces of some metals. Metals concentrations were always under the maximum concentration levels suggested by Mexican regulations. 15 different surfactants were used to identify the one with the capability to achieve the highest TPH removal. Surfactants included 5 anionics, 2 zwitterionic, 5 nonionics and 3 natural gums. Sulfopon 30 at a concentration of 0.5% offered the best surfactant performance. The TPH removals employing the different surfactants were in the range from 38% to 68%, in comparison to the soil washing with water (10% of TPH removal). Once the surfactant was selected, 70 kg of soil were washed and the resulting water contained approximately 1300 mg/L of COD, 385 mg/L of BOD (BOD/COD = 0.29), 122 mg/L of MBAS, and 212 mg/L of oil and greases, among other contaminants.展开更多
Sulfide precipitation flotation of copper iron bearing acidic waste water from a large copper mine and the stimulated waste water were studied. The pH of the waste water was 2.2, with 130 mg/L Cu 2+ and 500 mg/L Fe 3+...Sulfide precipitation flotation of copper iron bearing acidic waste water from a large copper mine and the stimulated waste water were studied. The pH of the waste water was 2.2, with 130 mg/L Cu 2+ and 500 mg/L Fe 3+ (Fe 2+ ). Results show that, when Na 2S was added as precipitating agent, sodium butylxanthate as collector and at pH 2.0, the removal of copper could be as high as 99.7% and the residual copper decreased to 0.2 mg/L, however, almost no iron was removed. When the floated solution was neutralized to pH=8.0, more than 98% iron was precipitated and the residual iron was less than 10 mg/L. In experiment on actual mine effluents, after the use of precipitate flotation technology to recover copper and pH neutralization to precipitate iron, the treated waste water does meet the emission standards for sewage and valuable floating copper graded 37.12%. The chemical calculation and mechanism of solution were also presented.展开更多
Acid Rock Drainage (ARD) is a well-known problem related to the mining industry due to its hazardous environmental effects. Metal-rich drainage and acid effluent transmitted from mine waste dumps compromise environmen...Acid Rock Drainage (ARD) is a well-known problem related to the mining industry due to its hazardous environmental effects. Metal-rich drainage and acid effluent transmitted from mine waste dumps compromise environmental quality of groundwater and surface water systems destroying aquatic life and increasing human health risks. This study was aimed at assessing the acid and metal drainage potential from the Subriso East Rock Dump (SERD) located in the Wassa East district of Ghana on ground and surface water quality in the catchment using a system of monitoring boreholes, reference boreholes and river samples. Water samples were collected from deep and shallow monitoring boreholes and surface water within the immediate environs of the SERD from August 2012 to February 2013 for laboratory and statistical analysis. Parameters analyzed include sulphate, alkalinity, Arsenic (As), Manganese (Mn), Iron (Fe), Zinc (Zn), Copper (Cu), Cadmium (Cd), Mercury (Hg), Aluminum (Al), Silver (Ag) and lead (Pb) and their concentrations compared with Ghana Standards Authority (GSA) GSB (2009) and WHO (2017) standards. Results indicate that surface and groundwater were not impacted by the SERD possibly because there was no generation of acid or metal-loaded effluent from the SERD into the environment. Physicochemical variables between monitoring boreholes did not differ significantly from conditions in the reference boreholes. Similarly, comparison of upstream and downstream river conditions did not yield any statistical significance (p > 0.05). Mn and Fe concentrations were above the WHO (2017)/GSB (2009) standards. Heavy metal concentrations in surface and groundwater were below detection limits except manganese and iron whose concentrations exceeded the recommended guidelines. No significant environmental impacts exist that could be attributed to the waste rock dump and may be as a result of engineering designs and mechanisms which prevent acid generated water from reaching the external environment. Furthermore, the geology of the study area potentially could be slightly inert having the potential to generate ARD under appropriate conditions. Again, the young age of the waste rock dump is a factor that may contribute to ARD generation under appropriate condition. Routine monitoring of groundwater and surface water sources is required to determine future acid generation of the SERD and its environmental impacts. The results of this study will assist decision makers and environmental managers to plan effectively to mitigate future impacts as mining waste rock dumps are known to increase in acid generation potential with age.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
The emulsion liquid membrane technique was used to extract amino-J acid from industrial dye waste-water.The effects of stirring speed,ratio of the emulsion to water(Rew),ratio of the oil to internal phase(Roi)and memb...The emulsion liquid membrane technique was used to extract amino-J acid from industrial dye waste-water.The effects of stirring speed,ratio of the emulsion to water(Rew),ratio of the oil to internal phase(Roi)and membrane phase components on the extraction rate were investigated and optimized.The results showed that the extraction rate of amino-J acid approached 97% when the stirring speed was 300 r/min,Rew 1:6,Roi 1:1,trioctylamine(TOA)3 mL/100 mL kerosene,and methyl?didecyle?alcohol?acrylate(LMA-2)3 g/100 mL kerosene,respectively.The extraction rate had not changed with the oil phase reused for times.展开更多
Wastewaters from the chemical industry are usually of high-strength and may contain minor inhibitory and recalcitrant organics that are at times not readily identifiable. This paper describes the experience of a biolo...Wastewaters from the chemical industry are usually of high-strength and may contain minor inhibitory and recalcitrant organics that are at times not readily identifiable. This paper describes the experience of a biological waste water treatment plant （WWTP） processing a COD concentration of 43000 mg·L^-1 wastewater from an oxochemical manufacturing plant. Stage improvements of the plant process by dilution of the inhibitory influent using other chemical wastewater streams resulting in a synergistic process effect, and removal of inhibitory organics by phase separation via acidification, effectively achieved process optimization producing a high quality effluent. In particular, the COD removal efficiency of granular sludge based anaerobic reactors increased from 56% to 90%. The final effluent COD decreased from 250mg·L^-1 to 50mg·L^-1, consistently meeting the COD concentration of 100 mg·L^-1 regulatory discharge limit. The success of the process enhancements supports the hypothesis that long-chain quaternary carboxylic acids act as substrate inhibitors in the biological process.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
Humic acid(HA)was carbonized at 300,400 and 500℃ and then functionalized with 1 wt%–12 wt%Fe(Ⅲ)respectively[CHA300/400/500-Fe(Ⅲ)].Adsorption of such Fe(III)-functionalized carbonized HA as adsorbents to aqueous te...Humic acid(HA)was carbonized at 300,400 and 500℃ and then functionalized with 1 wt%–12 wt%Fe(Ⅲ)respectively[CHA300/400/500-Fe(Ⅲ)].Adsorption of such Fe(III)-functionalized carbonized HA as adsorbents to aqueous tetracycline(TC:25 mg·L^-1)was studied.The adsorption equilibrium time for CHA400-Fe(Ⅲ)to TC was 6 h faster and the adsorption removal efficiency(Re)was two times higher than that of HA/CHA.The adsorption Reof CHA400-Fe(Ⅲ)loaded 10%iron[CHA400-(10%)Fe(Ⅲ)]to TC could reach 99.8%at 8 h and still kept80.6%after 8 cycles.The adsorption kinetics were well fitted to the pseudo-second-order equation and the adsorption isotherms could be well delineated via Langmuir equations(R^2N 0.99),indicating that the homogeneous chemical adsorption of TC occurred on the adsorbents.The main adsorption mechanisms of TC were complexation Fe(III)and hydrophobic distribution.Electropositive and electronegative repulsion between TC and CHA400-(10%)Fe(Ⅲ)at lowly p H(2)and highly p H(8–10)respectively,leaded to the relatively low adsorption capacity and more notable influence of ion concentration.When the p H was between 4 and 8,TC mainly existed in neutral molecules(TCH2),so the influence of ion concentration was not obvious.The dynamic adsorption results showed that the CHA400-(10%)Fe(Ⅲ)could continuously treat about 2.4 L TC(27 mg·L^-1)wastewater with the effluent concentration as low as 0.068 mg·L^-1.Our study suggested a broad application prospect of a new,effective,lowcost and environment-friendly adsorbent CHA400-(10%)Fe(Ⅲ)for treatment of low-concentration TC polluted wastewater.展开更多
Surfactants are widely used in the petroleum industry as one kind of Enhanced Oil Recovery methods (EOR). The oil sands mines in Northern Alberta are the largest one in the world. Due to using sodium hydroxide in bitu...Surfactants are widely used in the petroleum industry as one kind of Enhanced Oil Recovery methods (EOR). The oil sands mines in Northern Alberta are the largest one in the world. Due to using sodium hydroxide in bitumen extraction process, there are a lot of surfactant molecules in the tailing water. The surfactants from oil sands industry have brought a potential threat to the environment and human health. Depending on the performance of surfactant at the interface, this work focuses on removing these harmful surfactants from the tailing water and not bringing other possible hazardous substances. Moreover, a mathematical model is built to calculate the removal efficiency of the surfactant. The time required for removing the surfactant is determined experimentally. In conclusion, most of surfactant molecules are adsorbed at the oil/water interface. The fraction of the surfactant staying at the oil/water interface is high. Most of the surfactants in tailing water can be eliminated. The time of surfactant migration can be used for setting up the update time of the oil film in the automatic instrument, which can be designed in the future.展开更多
Zn containing waste water from a viscose staple fiber plant has been treated using the emulsion liquid membrane (ELM) process since 1995. The flow sheet and operating parameters of the ELM process are introduced. A...Zn containing waste water from a viscose staple fiber plant has been treated using the emulsion liquid membrane (ELM) process since 1995. The flow sheet and operating parameters of the ELM process are introduced. After adjusting the membrane composition, changing the emulsion phase ratio, and adding a scrubbing step, the ELM process operated normally without trouble for emulsion splitting and mass transport throughput. The splitter voltage was decreased to 3.55 kV. The zinc concentration of treated waste water was lowered to less than 10 mg·L -1 . More than 95% of the zinc was recovered and reused.展开更多
文摘An old automotive industrial site located at Mexico City with many years of operation and contaminated with heavy oil hydrocarbons, particularly spent oils, was assessed for restoration using the surfactant enhanced soil washing (SESW) process. The main goal of this study was to characterize the contaminated soil in terms of TPHs, BTEX, PAHs, and metals contents as well as microbiologically (total heterotrophs and specific degrading microorganisms). We also aimed to determine the surfactant type and concentration to be used in the SESW process for the automotive waste oil contaminated soil. At the end, sixteen kg of contaminated soil were washed and the produced wastewater (approximately 40 L) was characterized in terms of COD, BOD;solids, and other physico-chemical parameters. The soil contained about 14,000 mg of TPH/kg soil (heavy fraction), 0.13 mg/kg of benzo (k) fluoranthene and 0.07 mg/kg of benzo (a) pyrene as well as traces of some metals. Metals concentrations were always under the maximum concentration levels suggested by Mexican regulations. 15 different surfactants were used to identify the one with the capability to achieve the highest TPH removal. Surfactants included 5 anionics, 2 zwitterionic, 5 nonionics and 3 natural gums. Sulfopon 30 at a concentration of 0.5% offered the best surfactant performance. The TPH removals employing the different surfactants were in the range from 38% to 68%, in comparison to the soil washing with water (10% of TPH removal). Once the surfactant was selected, 70 kg of soil were washed and the resulting water contained approximately 1300 mg/L of COD, 385 mg/L of BOD (BOD/COD = 0.29), 122 mg/L of MBAS, and 212 mg/L of oil and greases, among other contaminants.
文摘Sulfide precipitation flotation of copper iron bearing acidic waste water from a large copper mine and the stimulated waste water were studied. The pH of the waste water was 2.2, with 130 mg/L Cu 2+ and 500 mg/L Fe 3+ (Fe 2+ ). Results show that, when Na 2S was added as precipitating agent, sodium butylxanthate as collector and at pH 2.0, the removal of copper could be as high as 99.7% and the residual copper decreased to 0.2 mg/L, however, almost no iron was removed. When the floated solution was neutralized to pH=8.0, more than 98% iron was precipitated and the residual iron was less than 10 mg/L. In experiment on actual mine effluents, after the use of precipitate flotation technology to recover copper and pH neutralization to precipitate iron, the treated waste water does meet the emission standards for sewage and valuable floating copper graded 37.12%. The chemical calculation and mechanism of solution were also presented.
文摘Acid Rock Drainage (ARD) is a well-known problem related to the mining industry due to its hazardous environmental effects. Metal-rich drainage and acid effluent transmitted from mine waste dumps compromise environmental quality of groundwater and surface water systems destroying aquatic life and increasing human health risks. This study was aimed at assessing the acid and metal drainage potential from the Subriso East Rock Dump (SERD) located in the Wassa East district of Ghana on ground and surface water quality in the catchment using a system of monitoring boreholes, reference boreholes and river samples. Water samples were collected from deep and shallow monitoring boreholes and surface water within the immediate environs of the SERD from August 2012 to February 2013 for laboratory and statistical analysis. Parameters analyzed include sulphate, alkalinity, Arsenic (As), Manganese (Mn), Iron (Fe), Zinc (Zn), Copper (Cu), Cadmium (Cd), Mercury (Hg), Aluminum (Al), Silver (Ag) and lead (Pb) and their concentrations compared with Ghana Standards Authority (GSA) GSB (2009) and WHO (2017) standards. Results indicate that surface and groundwater were not impacted by the SERD possibly because there was no generation of acid or metal-loaded effluent from the SERD into the environment. Physicochemical variables between monitoring boreholes did not differ significantly from conditions in the reference boreholes. Similarly, comparison of upstream and downstream river conditions did not yield any statistical significance (p > 0.05). Mn and Fe concentrations were above the WHO (2017)/GSB (2009) standards. Heavy metal concentrations in surface and groundwater were below detection limits except manganese and iron whose concentrations exceeded the recommended guidelines. No significant environmental impacts exist that could be attributed to the waste rock dump and may be as a result of engineering designs and mechanisms which prevent acid generated water from reaching the external environment. Furthermore, the geology of the study area potentially could be slightly inert having the potential to generate ARD under appropriate conditions. Again, the young age of the waste rock dump is a factor that may contribute to ARD generation under appropriate condition. Routine monitoring of groundwater and surface water sources is required to determine future acid generation of the SERD and its environmental impacts. The results of this study will assist decision makers and environmental managers to plan effectively to mitigate future impacts as mining waste rock dumps are known to increase in acid generation potential with age.
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The emulsion liquid membrane technique was used to extract amino-J acid from industrial dye waste-water.The effects of stirring speed,ratio of the emulsion to water(Rew),ratio of the oil to internal phase(Roi)and membrane phase components on the extraction rate were investigated and optimized.The results showed that the extraction rate of amino-J acid approached 97% when the stirring speed was 300 r/min,Rew 1:6,Roi 1:1,trioctylamine(TOA)3 mL/100 mL kerosene,and methyl?didecyle?alcohol?acrylate(LMA-2)3 g/100 mL kerosene,respectively.The extraction rate had not changed with the oil phase reused for times.
文摘Wastewaters from the chemical industry are usually of high-strength and may contain minor inhibitory and recalcitrant organics that are at times not readily identifiable. This paper describes the experience of a biological waste water treatment plant （WWTP） processing a COD concentration of 43000 mg·L^-1 wastewater from an oxochemical manufacturing plant. Stage improvements of the plant process by dilution of the inhibitory influent using other chemical wastewater streams resulting in a synergistic process effect, and removal of inhibitory organics by phase separation via acidification, effectively achieved process optimization producing a high quality effluent. In particular, the COD removal efficiency of granular sludge based anaerobic reactors increased from 56% to 90%. The final effluent COD decreased from 250mg·L^-1 to 50mg·L^-1, consistently meeting the COD concentration of 100 mg·L^-1 regulatory discharge limit. The success of the process enhancements supports the hypothesis that long-chain quaternary carboxylic acids act as substrate inhibitors in the biological process.
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.
基金financially supported by the National Natural Science Foundation of China(No.51641209)。
文摘Humic acid(HA)was carbonized at 300,400 and 500℃ and then functionalized with 1 wt%–12 wt%Fe(Ⅲ)respectively[CHA300/400/500-Fe(Ⅲ)].Adsorption of such Fe(III)-functionalized carbonized HA as adsorbents to aqueous tetracycline(TC:25 mg·L^-1)was studied.The adsorption equilibrium time for CHA400-Fe(Ⅲ)to TC was 6 h faster and the adsorption removal efficiency(Re)was two times higher than that of HA/CHA.The adsorption Reof CHA400-Fe(Ⅲ)loaded 10%iron[CHA400-(10%)Fe(Ⅲ)]to TC could reach 99.8%at 8 h and still kept80.6%after 8 cycles.The adsorption kinetics were well fitted to the pseudo-second-order equation and the adsorption isotherms could be well delineated via Langmuir equations(R^2N 0.99),indicating that the homogeneous chemical adsorption of TC occurred on the adsorbents.The main adsorption mechanisms of TC were complexation Fe(III)and hydrophobic distribution.Electropositive and electronegative repulsion between TC and CHA400-(10%)Fe(Ⅲ)at lowly p H(2)and highly p H(8–10)respectively,leaded to the relatively low adsorption capacity and more notable influence of ion concentration.When the p H was between 4 and 8,TC mainly existed in neutral molecules(TCH2),so the influence of ion concentration was not obvious.The dynamic adsorption results showed that the CHA400-(10%)Fe(Ⅲ)could continuously treat about 2.4 L TC(27 mg·L^-1)wastewater with the effluent concentration as low as 0.068 mg·L^-1.Our study suggested a broad application prospect of a new,effective,lowcost and environment-friendly adsorbent CHA400-(10%)Fe(Ⅲ)for treatment of low-concentration TC polluted wastewater.
文摘Surfactants are widely used in the petroleum industry as one kind of Enhanced Oil Recovery methods (EOR). The oil sands mines in Northern Alberta are the largest one in the world. Due to using sodium hydroxide in bitumen extraction process, there are a lot of surfactant molecules in the tailing water. The surfactants from oil sands industry have brought a potential threat to the environment and human health. Depending on the performance of surfactant at the interface, this work focuses on removing these harmful surfactants from the tailing water and not bringing other possible hazardous substances. Moreover, a mathematical model is built to calculate the removal efficiency of the surfactant. The time required for removing the surfactant is determined experimentally. In conclusion, most of surfactant molecules are adsorbed at the oil/water interface. The fraction of the surfactant staying at the oil/water interface is high. Most of the surfactants in tailing water can be eliminated. The time of surfactant migration can be used for setting up the update time of the oil film in the automatic instrument, which can be designed in the future.
文摘Zn containing waste water from a viscose staple fiber plant has been treated using the emulsion liquid membrane (ELM) process since 1995. The flow sheet and operating parameters of the ELM process are introduced. After adjusting the membrane composition, changing the emulsion phase ratio, and adding a scrubbing step, the ELM process operated normally without trouble for emulsion splitting and mass transport throughput. The splitter voltage was decreased to 3.55 kV. The zinc concentration of treated waste water was lowered to less than 10 mg·L -1 . More than 95% of the zinc was recovered and reused.
