Water Quality; Wastewater Management Essay Example | Topics and Well Written Essays - 500 words

Water Quality; Wastewater Management - Essay Example The wastewater having very high amount of dissolved BOD or COD would require either biological treatment processes, like activated sludge treatment, trickling filters upflow anaerobic sludge treatment, or chemical treatment units like coagulation techniques, filtration with ion exchange etc. These methods would not be adequate for complete elimination of the dissolved impurities. For example in the case of municipal wastewater, the secondary treatment would results in the reduction of organic part of the total contaminants dissolved in it. On the other hand, the pollutants like nitrates and phosphates or bacterial/microbiological contamination would not be totally removed using these methods. Hence, advanced treatment operations are additionally required for the removal of the aforementioned impurities (Malzer, 2002). The treatment processes employed in such situations are classified as the tertiary treatment. The techniques are usually nitrification and denitrification units which a re also biological methods undertaken with the help of bacterial mass. On the other hand, phosphates too need specialized treatment units for its removal. Further, if the objective is to eliminate the bacterial contamination, disinfection systems need to be provided appropriately as the tertiary unit operation. Thus the methods used under the secondary and tertiary treatment units are of multiple types and each having different purpose. Thus in a typical treatment system where the secondary operations are dependent on the activated sludge plants, the operations consist of a series of inter linked units having a settling basin where the sludge is separated from the treated water, following by sludge thickening, sludge drying and sludge disposal. The treated water from the settling tank marks the end of secondary treatment operations the water would still