Yalcin Askin Oktem

Bio: Yalcin Askin Oktem is an academic researcher from Istanbul University. The author has contributed to research in topics: Wastewater & Hydraulic retention time. The author has an hindex of 4, co-authored 7 publications receiving 223 citations.

Cadmium removal using potato peels as adsorbent: kinetic studies

Abstract: In this study, untreated waste potato peels were used as adsorbents for treatment and cadmium removal mechanisms were investigated. Maximum removal efficiency was 76% at an initial concentration of 100 mg L–1 of Cd(II) at pH 5.8 in an aqueous solutions at room temperature; 7.61 mg of cadmium was removed per gram of adsorbent. However, as the initial concentration increased, the removal efficiency decreased. Under optimum conditions, two parameters equilibrium isotherms (Langmuir, Freundlich, Temkin etc.) were applied. The Freundlich isotherm has the highest correlation (99.9%) in isotherms. Isothermal adsorption capacity (KF) has 19.94 mg g–1 and heterogeneity factor (1/n) 1.0 were determined. In adsorption, it was found that both the boundary layer diffusion and the intra-particle diffusion steps were effective, and the determination of the adsorption rate showed that the Type I pseudo-second-order equation had a high correlation (99%) at all concentrations.

Microbial Growth Kinetics of an Anaerobic Acidogenic Bioreactor

Abstract: Kinetic evaluation of an acidogenic completely stirred tank reactor (CSTR) treating a chemical synthesis-based pharmaceutical wastewater was investigated. For kinetic modeling of the acidogenic reactor (Monod, Contois, Grau, et al.), first-order kinetic models were used. These models have high correlation coefficients in this study. Monod models have shown high correlation coefficients (99%) which were used in describing the process kinetics of the anaerobic acidogenic reactor. Kinetic studies showed that sludge yield (Y) and decay rate (Kd) were 0.25 mg VSS/mg COD and 0.79 1/day, respectively.

Pharmaceutical Industry Wastewater: Review of the Technologies for Water Treatment and Reuse

Abstract: Pharmaceutical compounds are typically produced in batch processes leading to the presence of a wide variety of products in wastewaters which are generated in different operations, wherein copious quantities of water are used for washing of solid cake, or extraction, or washing of equipment. The presence of pharmaceutical compounds in drinking water comes from two different sources: production processes of the pharmaceutical industry and common use of pharmaceutical compounds resulting in their presence in urban and farm wastewaters. The wastewaters generated in different processes in the manufacture of pharmaceuticals and drugs contain a wide variety of compounds. Further, reuse of water after removal of contaminants, whether pharmaceuticals or otherwise, is required by industry. In view of the scarcity of water resources, it is necessary to understand and develop methodologies for treatment of pharmaceutical wastewater as part of water management. In this review, the various sources of wastewaters in the pharmaceutical industry are identified and the best available technologies to remove them are critically evaluated. Effluent arising from different sectors of active pharmaceutical ingredients (API), bulk drugs, and related pharmaceutics, which use large quantities of water, is evaluated and strategies are proposed to recover to a large extent the valuable compounds, and finally the treatment of very dilute but detrimental wastewaters is discussed. No single technology can completely remove pharmaceuticals from wastewaters. The use of conventional treatment methods along with membrane reactors and advanced posttreatment methods resulting in a hybrid wastewater treatment technology appear to be the best. The recommendations provided in this analysis will prove useful for treatment of wastewater from the pharmaceutical industry.

Ecotoxicological and health concerns of persistent coloring pollutants of textile industry wastewater and treatment approaches for environmental safety

Abstract: Textile industry wastewater (TIWW) is considered as one of the worst polluters of our precious water and soil ecologies. It causes carcinogenic, mutagenic, genotoxic, cytotoxic and allergenic threats to living organisms. TIWW contains a variety of persistent coloring pollutants (dyes), formaldehyde, phthalates, phenols, surfactants, perfluorooctanoic acid (PFOA), pentachlorophenol and different heavy metals like lead (Pb), cadmium (Cd), arsenic (As), chromium (Cr), zinc (Zn) and nickel (Ni) etc. TIWW is characterized by high dye content, high pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total dissolved solids (TDS), total suspended solids (TSS), total organic carbon (TOC), chlorides and sulphates. Thus, requires adequate treatment before its final discharge into the water bodies to protect public health and environment. The treatment of TIWW is a major challenge as there is no particular economically feasible treatment method capable to adequately treat TIWW. Therefore, there is a need to develop a novel, cost-effective and eco-friendly technology for the effective treatment of TIWW. This review paper emphasizes on the different textile industry processes, wastewater generation, its nature and chemical composition, environmental impacts and health hazards and treatment approaches available for TIWW treatment. It also presents various analytical techniques used to detect and characterize TIWW pollutants and their metabolites, challenges, key issues and future prospectives.

Treatment options for wastewater effluents from pharmaceutical companies

Abstract: In recent years, concerns about the occurrence and fate of active pharmaceutical ingredients, solvents, intermediates and raw materials that could be present in water and wastewater including pharmaceutical industry wastewater has gained increasing attention. Traditional wastewater treatment methods, such as activated sludge, are not sufficient for the complete removal of active pharmaceutical ingredients and other wastewater constituents from these waters. As a result, complementary treatment methods such as membrane filtration, reverse osmosis and activated carbon are often used in conjunction with the traditional methods for treatment of industrial wastewater. Most of the literature published to date has been on the treatment of municipal wastewater. However, there is a growing body of research that looks at the presence of active pharmaceutical ingredients in industrial wastewater, the treatment of these wastewaters and the removal rates. This article, reviews these treatment methods and includes both traditional methods and advanced oxidation processes. The paper concludes by showing that the problem of pharmaceuticals in wastewaters cannot be solved merely by adopting end of pipe measures. At source measures, such as replacement of critical chemicals, reduction in raw material consumption should continue to be pursued as the top priority.