Performance of duckweed (Lemna minor L.) on different types of wastewater treatment

Abstract: Duckweed (Lemna minor L.) has a wide application in Turkey having suitable climatic conditions. In this study, the growth of duckweed was assessed in laboratory scale experiments. They were fed with municipal and industrial wastewater at constant temprature. COD, total nitrogen (TN), total phosphorus (TP) and ortho-phosphate (OP) removal efficiencies of the reactors were monitored by sampling influent and effluent of the system. Removal efficiency in this study reflects optimal results: 73-84% COD removal, 83-87% TN removal, 70-85% TP removal and 83-95% OP removal. The results show that the duckweed-based wastewater treatment is capable of treating the laboratory wastewater

Efficient Removal Approach of Micropollutants in Wastewater Using Membrane Bioreactor

In the recent past years, micropollutants that are pharmaceutically active compounds (PhACs) have been used extensively and have been discovered in raw sewage, wastewater treatment plants, effluents, surface, and groundwater with concentrations from ng/L to several μg/L. Even though many of these compounds are still not determined online, monitoring technology improvements progressed. Today’s wastewater treatment plants are not constructed to remove these micropollutants yet. Conventional activated sludge processes are used in the treatment of municipal wastewater but are not specifically designed for the removal of micropollutants. The remaining pharmaceuticals mix into surface waters. At that stage, they can adversely affect the aquatic environment and may cause issues for drinking water production. As the conventional methods are insufficient for removing the micropollutants, other alternative treatment methods can be applied such as coagulation-flocculation, activated carbon adsorption (powdered activated carbon and granular activated carbon), advanced oxidation processes, membrane processes, and membrane bioreactor. It has been observed that membrane bioreactor (MBR) can achieve higher and more consistent micropollutants removal. The removal of micropollutants is based on physicochemical properties of micropollutants and the conditions of treatment. Due to recent technical innovations and cost reductions of the actual membranes, the membrane bioreactor takes attention. In this study, membrane bioreactor experiments for micropollutants in drinking use, wastewater, and surface waters were investigated in detail based on literature investigations, and the feasibility of this method was evaluated

Evaluation of trophic state of lake Uluabat, Turkey

Abstract: Lake Uluabat, which is located in Marmara region, is one of the most productive lakes in Turkey. Due to concerns about potential pollution resulting from watershed sources and adjacent agricultural lands, a study of the trophic state of lake Uluabat was conducted during the period February 2003 to January 2004. Total nitrogen (TN), total phosphorus (TP), Secchi disc depth (SD) and chlorophyll a (Chl a) were analyzed monthly in order to assess the trophic state of the lake. According to calculated nutrient ratios, phosphorus was found to be the primary limiting nutrient in lake Uluabat. Carlson's trophic state index values, based on TP, SD and Chl a, indicated that lake Uluabat is an eutrophic system