Sulfate reducing bacteria were isolated from the soil sample of Roaster-Acid unit of Debari Zinc Smelter of Hindustan Zinc Ltd., India and were adapted for effluent water of Zinc hydrometallurgy plant to sustain zinc ...Sulfate reducing bacteria were isolated from the soil sample of Roaster-Acid unit of Debari Zinc Smelter of Hindustan Zinc Ltd., India and were adapted for effluent water of Zinc hydrometallurgy plant to sustain zinc concentration of about 500 ppm and iron concentration of about 160 ppm with high acidity （pH 〈 1.0）. Nutrient broth, whey, ethanol and sucrose were tested as carbon source for SRB （sulfate reducing bacteria） out of which whey was found as the best electron donor to expedite the rate of biological treatment with SRB. A two stage anaerobic bioreactor was developed with a treatment capacity of 30 L effluent water in 4 days. The concentration of heavy metals in the treated water was within the permissible limits. The suggested methodology generates no solid waste, is environment friendly and may be commercially implemented for treatment of zinc plant effluent.展开更多
The aim of the present work is to remove heavy metals （copper, manganese, and zinc） from industrial wastewater of Baiji refinery using GAC （granular activated carbon）. The most important factors affecting adsorpti...The aim of the present work is to remove heavy metals （copper, manganese, and zinc） from industrial wastewater of Baiji refinery using GAC （granular activated carbon）. The most important factors affecting adsorption process have been studied, which are granular activated carbon thickness, H, inlet pollutant concentration, Cv, and liquid hourly space velocity, LHSV. All experiments were performed under constant temperature at 25℃ and pH = 7. The experimental apparatus was designed and constructed to enable controlling of the operating conditions. Employing five levels for each of H and LHSV and three levels for Co required 75 runs for each metal. Box-Wilson method was used to reduce the number of experiments to 15 for each metal. The results indicated that copper, manganese, and zinc can be completely removed from wastewater using activated carbon. However, breakthrough time for zinc is low. It is also shown that breakthrough time （TB） and exhaustion time （TE） are inversely proportional with pollutant concentration and LHSV （liquid hour space velocity） while it is directly proportional with the thickness of activated carbon column.展开更多
TOR （Tema oil refinery） is the only petroleum refinery in Ghana. To assess the quality of the wastewater, wastewater samples taken from three points of discharge into the treatment plant and the treated effluent wer...TOR （Tema oil refinery） is the only petroleum refinery in Ghana. To assess the quality of the wastewater, wastewater samples taken from three points of discharge into the treatment plant and the treated effluent were analyzed for physico-chemical characteristics. The levels of the pH, temperature, conductivity, COD （Chemical Oxygen Demand）, TDS （Total Dissolved Solids）, TSS （Total Suspended Solids） and phenol were assessed from January to June, 2011. The results obtained indicate varied levels of contaminants in both the untreated and treated wastewater. The average values of the treated effluent parameters analyzed were 38 ℃, 6,258 μs.cm-1, 314 mg-L-1, 115 mg.L-1, 2,689 mg-L-1 and 1 mg.L-1 for the temperature, conductivity, COD, TDS, TSS and phenol, respectively. The results suggest that both the raw wastewater and the treated effluent did not meet the discharge limit set by Ghana Environmental Protection Agency. Therefore, the treated effluent required additional treatment before it can be discharged into the environment. This suggests that the wastewater treatment plant of TOR is ineffective for the type of wastewater produced.展开更多
文摘Sulfate reducing bacteria were isolated from the soil sample of Roaster-Acid unit of Debari Zinc Smelter of Hindustan Zinc Ltd., India and were adapted for effluent water of Zinc hydrometallurgy plant to sustain zinc concentration of about 500 ppm and iron concentration of about 160 ppm with high acidity （pH 〈 1.0）. Nutrient broth, whey, ethanol and sucrose were tested as carbon source for SRB （sulfate reducing bacteria） out of which whey was found as the best electron donor to expedite the rate of biological treatment with SRB. A two stage anaerobic bioreactor was developed with a treatment capacity of 30 L effluent water in 4 days. The concentration of heavy metals in the treated water was within the permissible limits. The suggested methodology generates no solid waste, is environment friendly and may be commercially implemented for treatment of zinc plant effluent.
文摘The aim of the present work is to remove heavy metals （copper, manganese, and zinc） from industrial wastewater of Baiji refinery using GAC （granular activated carbon）. The most important factors affecting adsorption process have been studied, which are granular activated carbon thickness, H, inlet pollutant concentration, Cv, and liquid hourly space velocity, LHSV. All experiments were performed under constant temperature at 25℃ and pH = 7. The experimental apparatus was designed and constructed to enable controlling of the operating conditions. Employing five levels for each of H and LHSV and three levels for Co required 75 runs for each metal. Box-Wilson method was used to reduce the number of experiments to 15 for each metal. The results indicated that copper, manganese, and zinc can be completely removed from wastewater using activated carbon. However, breakthrough time for zinc is low. It is also shown that breakthrough time （TB） and exhaustion time （TE） are inversely proportional with pollutant concentration and LHSV （liquid hour space velocity） while it is directly proportional with the thickness of activated carbon column.
文摘TOR （Tema oil refinery） is the only petroleum refinery in Ghana. To assess the quality of the wastewater, wastewater samples taken from three points of discharge into the treatment plant and the treated effluent were analyzed for physico-chemical characteristics. The levels of the pH, temperature, conductivity, COD （Chemical Oxygen Demand）, TDS （Total Dissolved Solids）, TSS （Total Suspended Solids） and phenol were assessed from January to June, 2011. The results obtained indicate varied levels of contaminants in both the untreated and treated wastewater. The average values of the treated effluent parameters analyzed were 38 ℃, 6,258 μs.cm-1, 314 mg-L-1, 115 mg.L-1, 2,689 mg-L-1 and 1 mg.L-1 for the temperature, conductivity, COD, TDS, TSS and phenol, respectively. The results suggest that both the raw wastewater and the treated effluent did not meet the discharge limit set by Ghana Environmental Protection Agency. Therefore, the treated effluent required additional treatment before it can be discharged into the environment. This suggests that the wastewater treatment plant of TOR is ineffective for the type of wastewater produced.
