Bio Waste Treatment

Abstract

The organic wastewaters emanated from industries and domestic sources if discharged to inland surface waters without proper treatment, will lead to damage of the environment. In order to protect environment, it is essential to treat these wastewaters originating from industrial or domestic sources by physical, chemical or biological methods. Since the composition of wastewaters is not uniform and complex in nature, biowaste treatment seems to be an economically viable solution. Certain organic chemical wastewaters are difficult to biodegrade and such wastewaters are considered to be recalcitrant. Nitroaromatic plant wastewaters fall under recalcitrant category of wastes. The acclimatization period of nitroaromatic wastewaters would be 4–6 weeks. Biowaste treatment takes an important role in treating various types of organic chemical industrial wastewaters and domestic wastewaters. Biological wastewater treatment can be either aerobic or anaerobic in nature. These microorganisms may be strict aerobes or anaerobes or could be facultative. Nevertheless biowaste treatment plays a key role in wastewater treatment system. Some organic industrial wastewaters can be easily treated so that the final biochemical oxygen demand (BOD) is almost zero. Interestingly certain recalcitrant organic compounds like nitroaromatic compounds are difficult to be degraded by aerobic bacteria. Even these recalcitrant compounds are treated by aerobic microorganisms after proper acclimatization and finally the treated wastewater contains simpler organic compounds that could be nontoxic in nature. Essentially the benzene ring is broken to simpler compounds like pyruvate and the treated wastewater can be discharged to inland surface water streams. Further the treated wastewater is subjected to bioassay test, so as to confirm its nontoxic nature. The fundamental concepts of the aerobic and anaerobic treatment along with a case study of nitroaromatic plant wastewaters are discussed in this chapter.