The use of polymeric adsorbent for decontamination of various sources of water was critically reviewed. This arises from the alarming increase in water scarcity in many parts of the world due to increase in population, which exerts immense pressure on the available water resources. Treatment of wastewater, stormwater and seawater via series of technological pathways like adsorption, desalination, advanced oxidation and solid-phase microextraction constitute new strategies for removal of toxins, antibiotics, complex matrix samples, and heavy metals for sustainable production of potable drinking water. This study reviewed the use of polymeric adsorbents such as nano-magnetic polymers (NMPs), polysaccharides, extracellular polymeric substances (EPS), and covalent organic polymers (COPs) for effective decontamination of water. These materials were critically analyzed with emphasis on their characteristics, strengths, drawbacks, as well as the enhancement techniques. Furthermore, the mechanisms of adsorption involved were also discussed. This review shows that polymeric adsorbents have demonstrated remarkable removal efficiency for several contaminants.
Non-biodegradable contaminants found in wastewater and sludge such as dyes, phosphorus, sulfamethazine and heavy metals, which commonly have a density < 5 g/cm3 and atomic weights ranging from 63.5 to 200.6 . Water pollution associated with release of these contaminants to the atmosphere has been a major environmental concern worldwide . The contaminants abound in the wastewaters released from modern chemical industries such as textile, dyestuffs, metal plating, paper, mining, fertilizer, battery manufacturing , metallurgical, pesticides, fossil fuel, tannery, mining and various plastics like polyvinyl chloride. The release of these contaminants into environment have been increased extensively by the recent rapid industrialization . Since they are not easily biodegradable and some completely non-biodegradable these contaminants tend to accumulate in living organisms as, unlike the organic types that are easily biodegradable . These toxic contaminants commonly found in treatment of industrial wastewaters include dyes, zinc, chromium, phosphorous, sulfamethazine, copper, mercury, nickel, arsenic, cadmium and lead. The occurrence of little quantities (< 1 ppm for some dyes) of dyes in water is highly noticeable and detrimental. Generally, about 2% of dyes produced form industries are directly discharged in wastewater . Wastewater generated from dyestuffs must be treated to eliminate dyes before they are discharged to the ecosystem because of the stringent restrictions on the organic content of the wastewater. Many of these dyes are hazardous, posing a severe hazard to aquatic life due to their toxicity and carcinogenicity. However, treating wastewater-containing dyes is arduous, because dyes are not degradable by aerobic digestion, recalcitrant organic matter, and are stable to oxidizing agents, light and heat.