Waste Water Treatment in Chemical Industries: The Concept and Current Technologies

Abstract

The world's chemical industries face formidable environmental regulatory challenges in treating their wastewater effluents. The present work aims at highlighting the various industrial wastewater treatment technologies currently available including physico-chemical and biological processes as well as constructed wetland and conventional or advanced oxidation processes. Activated carbon prepared from low cost material, Agricultural by-product materials or modified natural polymers, which is considerably efficient for removal of direct dyes from wastewater, is also discussed. Combinations of anaerobic and aerobic treatment processes are found to be efficient in the removal of soluble biodegradable organic pollutants. The use of membrane in final stage of industrial wastewater treatments is increasing. The chemical oxidation techniques to treat wastewater, classical chemical treatment and advanced oxidation processes, is discussed.

Recent developments in the application of sequencing batch reactor (SBR) technology for the petroleum industry wastewater treatment

“…Similarly, the settling time can be changed to allow complete settling before discharging. (Oliveira et al, 2008;Fakhru'l-Razi et al, 2010;Awaleh and Soubaneh, 2014). The cycles, hydraulic retention time (HRT), and sludge retention time (SRT) can be varied and hence it provides wide scope for treatment that is too in a single reactor which is most advantageous factor Mane and Munavalli, 2012).…”

“…SBRs can be applied as pre or post treatment options along with other treatment facilities successfully (Mane and Munavalli, 2012). Also, they may be utilized in denitrifying application (Oliveira et al, 2008;Fakhru'l-Razi et al, 2010;Awaleh and Soubaneh, 2014).…”

Increased photocatalytic activity induced by TiO 2 /Pt/SnO 2 heterostructured films

“…Considering the areas where water supply fails to meet demand, water reutilization is seen as a suitable alternative for addressing this issue. Among the major pollutants that contribute substantially towards environmental degradation are urban effluents and manufactured chemicals in general, including pesticides, dyes, lubricants, fertilizers, and detergents [1,2]. The need for more efficient yet less costly sustainable technologies for the treatment of effluents and for the control of environmental pollution has essentially become a matter of huge relevance.…”

Significance of pre-sedimentation tanks on SBR devices with the second level of treatment

“…in cycles. The cycle is the time interval required for filling the SBR tank with wastewater, reaction (biological and chemical processes), settling (separating activated sludge from effluent), and discharging the effluent and transporting the sludge for further treatment [10,11]. Each cycle is divided into a series of processes or phases.…”