Biotreatability of Industrial Hazardous Wastes

Hazardous waste contamination due to industrial activity is now identified as a potential risk to both the environment and serious health problems. This chapter explores the methods of biotreatments of industrial pollutants. Industrial pollutants can be stabilized by their hydrolysis, oxidation, reduction, precipitation, volatilization, and solubilization. The electrons in oxidation–reduction are donated by (a) organic compounds, (b) reduced inorganic substances such as NH4+, Fe2+, H2, H2S, S, (c) in oxygenic photosynthesis H2O act as an electron donor. In oxidation-reduction reactions, electron acceptors differ based on the specific metabolic pathway. During fermentation, a fraction of an organic molecule functions as the electron acceptor, facilitating the conversion of substrates into products. Conversely, in anaerobic respiration, electron acceptors include organic compounds like SO42–, CO2, Fe3+ NO3–, NO2–. Of particular interest is co-metabolism, a phenomenon where microorganisms utilize hazardous substances, both organic and inorganic, as a supplementary energy source. This simultaneous biodegradation process showcases the remarkable adaptability and versatility of microorganisms in their quest for sustenance. The efficacy of biodegradation processes for hazardous waste can be enhanced through mechanical disintegration techniques or by deferring the treatment of hydrophobic substances. These methods aim to increase the available reaction surface area, thereby facilitating the breakdown of pollutants by microorganisms. Additionally, the removal of hazardous substances from wastewater can be achieved through advanced oxidation processes. These techniques employ powerful oxidizing agents to degrade pollutants into harmless byproducts, thus contributing to the remediation of contaminated water sources. By the use of genetic engineering, microbial strains can be used to create an ability to degrade biodegradation of xenobiotics or to amplify this capability by amplification of respective genes. Building multimodal metabolic pathways to encompass the broadest spectrum of biodegradable xenobiotics and the pace of biodegradation is an alternative method for the destruction of industrially dangerous chemicals. In the biotreatment of hazardous wastes, self-aggregating microbial cells, flocs and granules, and artificially aggregated cells adsorbed on solid particles are frequently utilized.