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This study attempts to evaluate the applicability of chemical oxidation processes to polish biologically treated effluent of a plant manufacturing hardboard from waste paper to comply with the discharge limit of 120 mg l-1 chemical oxygen demand (COD). In the first step, a chemically assisted settling was applied. The optimum results were obtained with alum plus lime with the alum dose of 200 mg l-1. In the second step, chemically assisted settling effluent was fed into an activated sludge system and over 80% COD removal was achieved. In the last step of the experimental study, a series of ozone oxidation and Fenton oxidation methods were tested to remove residual COD. Ozone oxidation provided 80% COD removal. An ozone dose of 40 mg min-1 with a reaction time of two hours was found to be optimum. Catalytic ozonation by using ferric iron, as well as high pH ozonation, Fenton process and H2O2/O3 oxidation did not prove to be more efficient than plain ozonation under these study conditions. [ABSTRACT FROM AUTHOR]

Discusses the factors affecting color removal from reactive dye bath by ozonation. Effect of the chelating agent in terms of both time and ozone dose; Direct ozone reactions from oxidation of organic substances with ozone.

Investigates the effect of partial ozonation of textile wastewater for the optimization of color removal. Characteristics of the inlet and the outlet of biological treatment; Measurement of the polluting parameters associated with the textile industry.

Investigates the effect of chemical treatment applying coagulation-flocculation and settling on the magnitude of soluble residual COD in the biological treatment of textile wastewaters. Use of a cotton-synthetic finishing plants as post-treatment applications of chemical treatment; Segregation of reusable streams as coagulants.

Assesses the source-based nitrogen removal alternatives in leather tanning industry wastewater. Efficacy of magnesium ammonium phosphate precipitation for ammonia removal; Wastewater characterization of a bovine leather tannery.

Initial assessment of industrial structure and wastewater, characteristics is important for successful environmental management in an industrial district. This is particularly important for the cases where highly polluting industries such leather tanners are of concern. In this study, Biga Leather Tanners District was evaluated. The process characteristics, wastewater amounts, wastewater quality and their variations with time were defined. The district housed 46 tanning plants,processing mainly sheepskins with a total capacity of 66.5 tons skinper day. Process profile was prepared and checked with experimental data. Chemical treatability experiments were conducted to assess the pretreatment alternatives. Chemical precipitation preceded by catalytic air oxidation of sulfide was found to be an optimum pretreatment system providing COD and TKN removals up to 80% together with completechromium removal. Results of the study were evaluated and discussed.(C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved. [ABSTRACT FROM AUTHOR]

Chemical synthesis processes of the pharmaceuticals industry producewastewaters which are variable in character and highly strong. In-plant controls are important and highly effective in determining the final wastewater quality. At any rate several stages of treatment comprised of physical, chemical and biological are required to obtain a reasonable degree of treatment. The problem is further complicated in small-scale plants due to low volume of wastewaters and dilution requirements. In this study, a small-scale pharmaceuticals plant producingthree common active materials was experimentally evaluated to assessthe waste management alternatives. The processes were evaluated and a source-based pollution profile was prepared. Paracetamol wastewaters were found to be readily biodegradable. Omeprazole wastewaters could be biologically treated only after significant chemical treatment. Mephenoxalone wastewaters were in no case biologically degradable. Paracetamol and pretreated Omeprazole wastewaters could be biologicallytreated down to several hundreds of ppm COD at as high as 0.5 g COD/g VSS day F/M ratio after several fold dilution. Results of the studywere evaluated and discussed. [ABSTRACT FROM AUTHOR]

In this paper, the treatability of strong wastes originating from anorganic chemicals industry was studied. Literature data were evaluated to assess the applicability of conventional and advanced methods of treatment to highly concentrated wastewaters. A detailed treatability study was conducted on the wastewater, which was provided from a small-scale polyester manufacturing plant. The manufacturing process involved only esterification reactions, generating a wastewater with aCOD content of over 200,000 mgl-1. The applicable treatment methods to be tested were determined as biological treatment of activated sludge process with low organic loading and chemical oxidation with H2O2. Results of the biological treatability study indicated that 80% COD removal could be obtained with 10 days retention time, provided that the system was fed with a 1/100 diluted raw wastewater. Chemical oxidation of raw wastewater with H2O2 in acid conditions and using ferric chloride as catalyst yielded 70% COD removal. However, the dosage required to obtain this efficiency was about 1 kg H2O2 per m3 of wastewater. With these applications the wastewater was treated to yield a COD of lower than 2000 mg/l. Results of the study were discussed and evaluated considering complexity and cost of treatment. [ABSTRACT FROM AUTHOR]

Minimization of water use and reuse applications within industry hasrecently gained importance within the context of water conservation efforts. The leather tanning industry is one of the subject industries due to large amount of water to be disposed of together with a highpollution load. The leather tanning industry has a complex structurein terms of materials, processes and manufacturing practices. Therefore a systematic approach is required to assess water use practice. In this study, bovine leather processing was taken as an example. An extensive study was conducted as on-site evaluations and questionnaires in the Istanbul Organized Leather Tanning District to assess water use practices, patterns and minimization trends. Results of the studywere discussed and important aspects of water minimization practiceshave been pointed out. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved. [ABSTRACT FROM AUTHOR]

In this study, the theoretical basis and limitations of magnesium ammonium phosphate (MAP) precipitation are investigated and experimentally tested for leather tanning industry. The MAP precipitation is applied to leather tanning wastewaters for both segregated flows containing high ammonia concentrations and combined flows. Segregated flow treatment on smaller volumes of wastewater provided an ammonia concentration of down to 150 mg l-1 NH3-N. The resulting ammonia concentration of MAP precipitation on combined wastewater is at the level of domestic wastewater which eliminates the need of further nitrogen removal in the biological treatment and provides an effluent quality acceptable for the public sewer. [ABSTRACT FROM AUTHOR]

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.

Abandoned copper mines, located in Lefka-Xeros area by the Morphou bay were primarily producing copper. Secondary products, such as silver and gold were also produced for a century by cyanide leaching method. The residues of mining processes were deposited in large tailing ponds that were constructed with primitive technology. In this research, water samples from several different points of tailing ponds, Lefka river and coast of Morphou bay are collected. The laboratory analysis of the samples is then carried out, considering basic pollutant parameters such as copper. The cross-shore and Longshore numerical modelling technique is applied associating the wave climate and the morphologic characteristics of the Morphou bay with the laboratory results to measure long-term effects of the pollution, diffused into the Mediterranean sea.

Availability of water to the industry often becomes prohibitive, both in terms of quality and cost, in coastal areas. This study takes the textile industry and evaluates the prerequisites of water recovery and reuse. In this context, a large spectrum are studied for their water, the general quality of wastewater generated, quality and treatability of reuse wastewater streams, and expected changes in the overall effluent quality after segregation of the recovery wastewater portion.