CHINHOYI UNIVERSITY OF TECHNOLOGY
Reg Number C1112097k
Lecturer DR CHIGU
Discuss the roles of bioremediation at a wastewater (sewage) treatment plant
Microorganisms are used to change harmful substances to nontoxic substances. This is a new technology for treating chemical spills and hazardous waste. Bacteria, fungi and yeast need nutrients (such as carbon, nitrogen, phosphate, and trace metals) to survive. They break down organic (carbon-containing) compounds found in nature to get energy for growth. For example, soil bacteria use petroleum hydrocarbons as a food and energy source changing them into harmless substances of carbon dioxide, water and fatty acids.Humans need a safe water supply and a safe method of sewage disposal. Therefore domestic wastewater by bioremediation is the use of environmentally friendly biotechnology organisms (natural treatment system) to degrade or absorp of pollutants that endanger human health and other organisms. The ability of these organisms are absorbed, outlines, save (deposit) and cell metabolism. It is expected that the pollutants in the domestic wastewater can be reduced or lost by plants and aquatic animals. Basically the roles of bioremediation in wastewater treatment plant are as follows removal: there is removal of contaminants from the location by physical means without the need to separate from the host medium. Separation, a process that is explained as the removal of the contaminant from the host medium that is soil or water. Degradation is the one whereby contaminants are chemically or biologically destroyed or neutralized to produce less toxic compounds. Lastly containment is a process that immobilizes the surface and subsurface migration of the contaminants.
According to Joseph, 1995 the amount and activity of the population is increasing every year. Along with this increase also waste that is produced and released into the environment, either in the form of solid waste, liquid or gas. The volume of domestic waste increased by 5 million cubic meters per year in a certain part of the United states, with an increase in the average content of 50%. If allowed to continue to enter the environment directly will cause environmental problems, because the processing rate is lower than the natural rate of output and input. Components in the domestic wastewater can lead to an imbalance of aquatic ecosystems and human health, such as pathogenic microorganisms (e.g.Escherichia coli) and nutrients namely Nitrogen and the possible presence of hazardous substances or elements, the presence of N, P, As, Cr, and Se can cause toxicity. Domestic wastewater effluent discharged into public water bodies or agricultural utilization as raw water and fresh water fish breeding is not expected to contain a hazardous substance or more below the dangerous threshold, Domestic Wastewater Quality Standard: TSS 100 mg/L, BOD 100 mg/L and pH 6–9 (Water Quality Program Committee, 1996).
Bioremediation of Effluent Wastewater Plant remediate metal heavy Cd and Cr contained in the liquid waste and Ceratophyllum demersum remediate toxic metals. Bioremediation studies using aquatic animals, namely Anodonta woodiana (gravestone taiwan) and Limnodrilus hoffmeisteri (worm water) showed capable of absorbing harmful elements . The bioremediation ability of plants and aquatic animals is the reason of their use to degrade or absorb pollutants domestic wastewater. Wastewater treatment process is influenced by environmental factors, namely physical factors include humidity, temperature, rainfall, light, turbidity and sediment; chemical factors include degree of acidity (pH), the content of inorganic and organic elements, BOD, COD and content of nitrate compounds and phosphate; biological factors include the biomass of aquatic organisms and...
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