ABSTRACT
Technical applicability of zero discharge conditions is evaluated for the specific case of a large metal finishing industry located within the protection zone of a surface water body designated as a potential source for domestic water supply. Within the context of a sound water management strategy, a detailed process profile of the plant is established with relevant balance between water demand and wastewater generation. Quality restrictions for various water uses are identified. Wastewater flows are segregated depending on significant quality parameters. A comprehensive treatment scheme is defined for optimum wastewater recycle and reuse. Source allocation is made for the reuse of different streams of recycled wastewater. The study indicates that wastewater reuse can only be implemented with an efficiency of around 85-90% for the selected industry.
Subject(s)
Metals , Waste Disposal, Fluid/methods , Waste Management/methods , Water Purification/methods , Chemical Industry , Conservation of Natural Resources/methods , Industrial Waste/analysis , Reproducibility of Results , Water Supply/analysisABSTRACT
In this study, treatability of wastewaters generated from a water-based paint and allied products industry has been investigated. As the industry already houses a treatment facility that consists of a coagulation-flocculation unit followed by an activated sludge process, the experimental study focuses on using the existing treatment plant in the most efficient way. In this context the COD removal efficiencies and operating costs of different coagulants i.e., sodium bentonite, alum, FeCl(3) and FeSO(4) have been evaluated. By assessing the refractory COD content of the subsequent activated sludge system outlet, the coagulant yielding the optimal output has been addressed. The outcomes reveal that the optimum result can be obtained by applying 50 mg L(-1) of FeCl(3) coagulant at the original pH of the effluent.
Subject(s)
Paint , Waste Disposal, Fluid/methods , Waste Management/methods , Alum Compounds/chemistry , Coagulants/chemistry , Ferrous Compounds/chemistry , Flocculation , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/isolation & purification , Water Pollution/prevention & controlABSTRACT
The chemical treatability of wastewaters generated from a textile manufacturing plant performing wool, polyester, wool-polyester blends, woven fabric as well as yarn dyeing and finishing operations was investigated. Coagulation and flocculation experiments were conducted with alum, sodium bentonite and iron salts on wastewaters collected from both the fabric finishing line, after being subjected to in-plant control measures covering water conservation practices and segregation of reusable streams, and dyeing line. The effect of optimum treatment alternatives on the chemical oxygen demand (COD) values of different molecular weight cut-off fractions was also examined.
