For example, the use of inorganic aluminum salts, one of the most widely used flocculants in conventional water and wastewater treatments, is considered now to have a possible contribution to Alzheimer’s disease. Synthetic polymer flocculants are highly efficient; however, they show poor biodegradability and the residual toxic monomers may cause potential health impacts (e.g., carcinogenic effects).Therefore, the use of synthetic flocculants is questionable in water treatment, and the use of polyacrylamide derivatives as flocculants has been limited and will be strictly prohibited in many countries.10 For example, sludges treated with polyacrylamides in Germany will be excluded from disposal on areas under cultivation by the end of 2013.