Aerobic treatment of pharmaceutical wastewater in a biological reactor
Author(s)- Mohammad Zakir Hossain Khan, Mostafa.M.G
This study was designed a wastewater treatment plant with an aim at minimizing and/or removing of suspended solids, dissolved solids, nutrients, and toxic compounds, before it releases into a water body. A lab-scale batch type integrated aerobic biological treatment plant was constructed and operated for pharmaceutical wastewater treatment and its performance was evaluated. A cylindrical open tank was used as a reactor and passed air through the bottom of the tank. The maximum hydraulic retention time was 15 days. The treated water samples were collected every day and tested for its chemical oxygen demand (COD), total suspended solids (TSS), pH, conductivity, and total dissolved solids (TDS) to evaluate the efficiency of the plant. About 75% removal of COD was achieved employing hydraulic residence times of 15 days. The analyses results of the treated wastewater reveal that the parameters pH, BOD, COD, TSS, TDS and color were found within the prescribed permissible limits indicating the efficiency of the plant. The results of this study demonstrate the potential for air injection to accelerate the biological treatment process, with greatest influence on COD removal from the wastewater.
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Experimental studies on effect of Heavy Metals presence in Industrial Wastewater on Biological Treatment
Author(s)- Majid Sa’idi
Biological Wastewater Treatment is one of the most important parts of wastewater treatment and microorganism has importance role in biological treatment. Microorganisms effect in metabolism of various organic compounds and other elements. Such microbiological parameters as the number, weight and activity of microorganisms can be good indicators of wastewater contamination with heavy metals. Heavy metals are known as harmful pollutants in Wastewater having a negative effect on Biological Wastewater Treatment plant including microorganisms. Some heavy metals, e.g. lead, even at low levels are toxic for microorganisms. As a rule, heavy metal has a negative effect on the growth of water microorganisms as it can greatly depress their numbers. On one hand, the number of microorganisms depends on the total content and concentrations of particular forms of heavy metals. On the other hand, it is conditioned by several other factors, quantity and quality of organic matter, especially carbohydrate rich organic matter, pH, total exchange capacity, nutrient availability, moisture, temperature and oxygen availability. Heavy metals shift the structure of microbial populations, impoverish their diversity, and affect species composition, reproduction and activity of indigenous microorganisms. Contamination of wastewater with high rates of heavy metals caused a significant decrease in the numbers of bacteria in biological system. It is obvious that heavy metals are very danger contaminant in wastewater and disorder of biological wastewater treatment is as a result of this pollution.
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