Moreover, the long polymer chain may facilitate the contact between the polymer and the contaminated medium. Their polycationic properties allow them the ability to conglomerate and precipitate in neutral or alkaline pH. It is becoming increasingly documented that the nontoxic and biodegradable biopolymers such as chitin and chitosan could be used in wastewater treatment. Moreover, organic and inorganic contaminants are effectively removed to meet increasingly stringent environmental quality standards. It poses a danger to water quality when discharged into rivers and lakes. Hence, industrial wastewater creates a serious environmental problem. They belong to various classes such as pesticides, fertilizers, hydrocarbons, phenols, plasticizers, biphenyls, detergents, oils, greases, pharmaceuticals, etc. Industrial effluents are discharges from various industries, and various organic pollutants have been found in different water resources. Suneeta Kumari, Rupak Kishor, in Handbook of Chitin and Chitosan, 2020 1.7.2 Wastewater treatment For these reasons, all industrial effluents may vary in quality and, obviously, in the corresponding pollution load. Raw industrial wastewater is generally produced continuously during the industrial process, but can include some other liquid wastes such as washing residues and sometimes process water, in case of an incident. Organic pollution (with major pollutants), high salinity Steel industry Electroplating industry Extractive industry High organic pollution, not easily biodegradable High organic pollution, easily biodegradable As a consequence, modifications in instrumentation, sampling, and sample preparation techniques have become essential to comply with the regulatory water standards, as well as to achieve a faster speed of analysis. Approved analytical methods exist for compliance monitoring of conventional pollutants in industrial effluents however, because of the complexity of the sample matrix, several analytical methods are required to determine polar and nonpolar organic compounds and new emerging pollutants that may impact water quality. One of the distinguishing characteristics of effluents of industrial origin, as compared to municipal wastewaters, is that often they may contain a mixture of different and very toxic substances. These compounds may be the final products, precursors, or intermediates of the process, or impurities and by-products. On the other hand, a chemical company may release a large number of different chemicals, which are not considered by regulatory requirements and in many cases are unknown. The emission of industrial pollutants in liquid effluents has to comply with stringent regulatory requirements and guidelines, in which chemicals listed should not exceed a given concentration. Industrial effluents result from various types of industrial processes and disposal practices, and may contain pollutants at levels that could affect the quality of receiving waters, as well as the aquatic ecosystem ( Table 1). Membrane treatments are becoming more popular as membranes become cheaper, but they are still generally far more expensive and less robust than traditional processes, so they have a long way to go before they will be the designerвЂ™s first choice options. These processes offer very good nonspecific removal of solids, fats/oils/greases, colloidal matter, and several substances (such as dyestuffs) that bind to the surface of the floc particles. The most common treatments are therefore coagulation/flocculation followed by settlement, filtration, or flotation. The key to both low cost and robustness is usually avoiding novelty. Nonspecificity of processes is key to robustness: designs need to remove entire classes of contaminant, rather than specific ones. The general principle is still the same: a stage-by-stage reduction in contaminants of decreasing particle size.Д¬ost and robustness are very important in industrial effluent treatment. Treatment of industrial effluent involves combining techniques from sewage treatment with those used in potable water treatment, as well as several specialist techniques. It is, however, common for industrial facilities to carry out some or all the treatment of their effluent on-site. Industrial effluents discharged to sewer form an important part of the load on the average sewage treatment plant. SeГЎn Moran, in An Applied Guide to Water and Effluent Treatment Plant Design, 2018 Introduction: An Overview of Industrial Effluent Treatment

Sewage effluent definition