Chapter 2 - Role of bacteria and algae in remediation of heavy metals from wastewater treatment plants

Abstract

The discharge of wastewater effluents is considered among the most dangerous ecologic problems the world has been facing since the 20th century because of the numerous sources of discharge that contain large amounts of heavy metals and their several negative impacts on animal and human health alike. Many methods and processes have been proposed over the years in order to purify wastewaters by collecting the heavy metals and hence preventing a serious threat to the environment. However, most of these methods are hardly considered effective because of several problems such as high operational costs and lack of selectivity. Interestingly, biosorption has emerged as an innovative technique that could be the solution to both heavy metal remediation from wastewaters and industrial effluents and high operational costs and biodegradability. Biomass based on bacteria and algae have drawn a lot of attention recently owing to their impressive compositions and their promising potential of adsorbing heavy metals efficiently from wastewaters. In this chapter the problems regarding heavy metals will be addressed alongside the new suitable way to overcome them, which is biosorption. The mechanism involving the biosorption process will be discussed with the various materials and techniques used for it, with an emphasis on the structures of bacterial biomass and algae that will be reviewed alongside their most important parameters related to their ability to purify wastewaters by removing heavy metals. The chapter also displays some results that help in acknowledging the importance of bacteria and algae in the remediation of heavy metals and discusses the role of bacterial and algal biomass in wastewater treatment plants for the purification of water and industrial effluents containing heavy metals.