Chapter 5 - Role of biofilms to curb contamination in water bodies

Abstract

Biofilms are an aggregate of microbes enclosed within extra polysaccharides. These microbes attach themselves to the substrate via polymers, protein, and DNA complexes. Biofilm provides microbes with a unique environment that protects them from environmental hazards. Biofilms formed by single species are predominant but the consortium biofilms have a better ability to combat remediation because of the ability of division of labor mechanism of each individual species. Biofilms in nature exist in rivers, lakes, and all the water bodies. These biofilms follow the process of attachment to the substrate, formation of monolayer and slime production and colonization utilizing multilayer cells, further, the mature biofilms detach from the slime layer. Pollution in water bodies is growing at an alarming rate and this creates ecological stress in water bodies. Water pollution occurs when an unwanted substance contaminates the environment. The main agents (causative) that are responsible for contamination in the water bodies are usually heavy metals, limiting or excessive nutrient availability, pesticides, pharmaceuticals and thereby leading to changes in water properties. The main conventional treatment process includes physical, chemical, and biological treatments to combat contamination in water bodies. Physical treatments include processes such as screening, sedimentation, and filtration whereas chemical treatment includes coagulation, precipitation and disinfection, and biological treatment that involve the dissolved and suspended organic matter. Biofilms provide possible remediation by absorption, immobilization, and degradation of organic matter. Biofilms are providing better insights to combat remediation. In the present chapter, we will focus on conventional methods of treatment, the basics of biofilms, and their mechanism to curb contamination in water bodies.