Natural coagulants: analysis of potential use for drinking water treatment in developed and developing countries

Abstract

a b s t r a c tDrinking water must be colorless, odorless and tasteless, and free of substances or micro-organisms that can cause disease. The process to obtain drinking water is purification, understood as the treatment to make water suitable for human consumption. Water purification is traditionally composed of a sequence of standard treatments including coagulation-flocculation, sedimentation, filtration, and disinfection. Some compounds named coagulants are used for coagulation-flocculation, which is the stage in which the suspended matter is removed and the water is clarified. Coagulants are usually synthetic, therefore represent a high cost and are difficult to gets in some areas, especially in developing countries. In addition, their use is being revised and restricted in different international standards, in order to control or prohibit its use because of the possible hazard effects that the remains of these products in treated water can cause to people. In contrast to synthetic coagulants, there are several natural compounds with coagulation properties which have some advantages such as easy availability and safety. At present, scientific community is paying more attention to natural coagulants as legal restrictions to synthetic ones are becoming more severe. This paper is a review of natural coagulants as an alternative to chemical coagulants, in which their potential application in the treatment of drinking water is analysed.

Recent Achievements in Polymer Bio-Based Flocculants for Water Treatment

“…Flocculants found applications in various types of technological processes that require purification of water from different types of suspended particles (inorganic, organic, and microbial). They are used, among others, in the dairy industry, petroleum industry, mining, metallurgy, papermaking, and in the treatment of drinking water and municipal sewage [ 5 , 30 , 247 , 248 ]. Currently, many scientific works are devoted to obtaining bioflocculants of plant or, less frequently, animal origin.…”

Moringa oleifera Plant as potent alternate to Chemical Coagulant in Water Purification

“…These coagulants are further classified into various categories including synthetic coagulant, inorganic coagulant and natural coagulant. Natural coagulants pose several benefits to mankind which can overcome the side effects of chemical coagulants such as aluminum salts which are associated with several human diseases including Alzheimer's disease (Krupińska, 2020;García-Fayos, Arnal Arnal, Sancho, 2018). Natural coagulants…”