Alpaslan Ekdal

Evaluating the impact of climate change on groundwater resources in a small Mediterranean watershed.

Western Mediterranean Region of Turkey is subject to considerable impacts of climate change that may adversely affect the water resources. Decrease in annual precipitation and winter precipitation as well as increase in temperatures are observed since 1960s. In this study, the impact of climate change on groundwater resources in part of Köyceğiz-Dalyan Watershed was evaluated. Evaluation was done by quantifying the impacts of climate change on the water budget components. Hydrological modeling was conducted with SWAT model which was calibrated and validated successfully. Climate change and land use scenarios were used to calculate the present and future climate change impacts on water budgets. According to the simulation results, almost all water budget components have decreased. SWAT was able to allocate less irrigation water because of the decrease of overall water due to the climate change. This resulted in an increase of water stressed days and temperature stressed days whereas crop yields have decreased according to the simulation results. The results indicated that lack of water is expected to be a problem in the future. In this manner, investigations on switching to more efficient irrigation methods and to crops with less water consumption are recommended as adaptation measures to climate change impacts.

Chemical treatability of dairy wastewater

Chemical treatability of dairy wastewater originating from a dairy and dairy products plant at Istanbul was investigated on the basis of chemical oxygen demand (COD) parameter as a pre‐treatment alternative. FeCl3, FeSO4 and alum were used as coagulants in the jar‐test experiments of four sets of daily composite wastewater samples taken once every month. The effect of acid cracking has also been searched through acid addition and pH adjustment. Characterisation studies demonstrated that wastewater characteristics varied within a wide range in spite of no significant production changes at the plant during the experimentation period. Optimum coagulant dosage has been determined as 200mg l–1 for all the coagulants with the optimum pH values between 4 and 4.5 for FeCl3 and FeSO4, and 5‐6 for alum. Maximum overall COD removal efficiencies were obtained as 72 per cent, 59 per cent and 54 per cent for FeCl3, FeSO4 and alum, respectively. Nevertheless, COD removal efficiencies were found to be inadequate to meet the current discharge standards of Greater Metropolitan Istanbul to sewer systems indicating that chemical treatment is insufficient for discharging chemically pre‐treated dairy wastewater to a sewage system, which was actually the main objective of the study. The results showed that the wastewater composition greatly influences the maximum removal efficiencies and also the conditions for optimum coagulation. However, attention to such chemical treatment studies on dairy wastewater has started to accelerate within the last decade in various countries of the world, such as United Arabic Emirates and Scandinavian countries where the targets of applying chemical treatment varied. In Scandinavian countries, biodegradable coagulants have been applied to use the sludge arising from the system for livestock feeding, leading to reuse of sludge. In Arabic Emirates, chemically treated dairy effluents are utilised for irrigation purposes. These recent studies point out that application of chemical treatment to dairy wastewater with various coagulants lead to a variety of utilities apart from being a pre‐treatment alternative.

Fate of nonylphenol ethoxylate (NPEO) and its inhibitory impact on the biodegradation of acetate under aerobic conditions

This study evaluated the kinetics of nonylphenol ethoxylate (NPEO) and acetate biodegradation at a moderate sludge age by acclimated culture under aerobic conditions. A laboratory-scale sequencing batch reactor was set and fed only with acetate mixture. The system was operated at steady state with a sludge age of 8 days. Following this stage, a mixture of NPEO and acetate was fed to the mixed culture in order to assess the biodegradation kinetics of NPEO and its impact on acetate utilization. A mechanistic model was developed involving model components and kinetic parameters for both substrates. The model was calibrated with parameters such as oxygen uptake rate and polyhydroxyalkanoates. Biodegradation characteristics and kinetics of acetate and NPEO were estimated by using the model results. Evaluation of calibrated model indicated that exposure of NPEO to non-acclimated sludge caused significant inhibitory impact on the utilization and storage of acetate. However, acclimation of biomass greatly suppressed inhibitory effects of NPEO on growth process involved in the degradation of acetate.

Application of Water Quality Modelling as a Decision Support System Tool for Planned Buyuk Melen Reservoir and Its Watershed

Istanbul, the largest metropolis of Turkey and one of the most crowded metropolises in the world, is facing the risk of water scarcity. Analyses indicated that one of the alternative solutions coping with this problem is water transfer from a watershed that is located outside the administrative boundaries of Istanbul. Due to its water potential and relatively less degraded water quality, Buyuk Melen Watershed was considered to be the most feasible option. As the result of analyses, State Hydraulic Works (DSI) has planned construction of a reservoir in the Buyuk Melen Watershed to supply the required amount of water for Istanbul also in low flow seasons. Since the reservoir will be located at the downstream region of the watershed, its water quality will be affected by human-induced activities, thus measures need to be taken to prevent pollution prior to reservoir construction. Quantifying the response of the planned reservoir to external pollution loads is an important step in the planning and management of the watershed. Mathematical modelling is a useful tool for estimating the future water quality and understanding the possible responses of the reservoir to various pollution loads. In this study, a water quality model capable of simulating hydrodynamics, transport and water quality in reservoirs is used for preliminary estimation of possible impacts of several management options in the watershed. Model results indicated that, all of the point sources in the watershed must be controlled by advanced wastewater treatment and should be diverted from the streams and the planned reservoir. Model results also indicated that reduction of agricultural diffuse loads by 30–40% is expected to have a perceptible improvement of reservoir water quality.

An overview of integrated and interdisciplinary studies on conservation of a coastal lagoon system in Turkey

This paper presents part of the results of ongoing integrated and interdisciplinary studies conducted at a vulnerable coastal lagoon system with the aim of protecting it from further anthropogenic pollution. The target area is in southwestern Turkey, consisting of a lake that joins the Mediterranean Sea via a lagoon channel system. Land resources in the watershed are identified, including all the elements of the physical environment that influence potential land‐use, and are illustrated by the application of geographical information systems through mapping and visualization of various thematic layers of land. This study will enlighten those working on lagoon watersheds aiming at conservation of natural resources since it states the results of the studies conducted so far through various disciplines, and presents how data are utilized by the groups in an integrated manner. Based on the available data, pre‐modelling studies on hydrodynamic modelling and on water quality modelling are also referred. Identification of a watershed depends on gathering satisfactory data, which will further be used to establish sustainable development and management plans, apart from utilizing the obtained data for watershed and hydrodynamic modelling approaches and to better understand such complex systems.

Land-Based Sources, Water Quality and Management

ANGHELUTA VADINEANU1, BRENDA RASHLEIGH2, MELIKE GUREL3, ALPASLAN EKDAL3, AMIR ALIYEV9, ANGEL PEREZ RUZAFA4, CIǦDEM TAVŞAN3, ELENA PREDA1, ERIC MASSON5, EUGENIUSZ ANDRULEWICZ6, MARS AMANALIEV, NUR FΙNDΙK HECAN7, OTUZBAY GELDIYEW10 AND SOFIA GAMITO8 1 Department of Systems Ecology and Sustainability, University of Bucharest, Romania 2 U.S. Environmental Protection Agency, Athens, Georgia, USA 3 Environmental Engineering Department, Istanbul Technical University, Turkey 4 Fac. Biologia. Universidad de Murcia, Spain 5 University of Sciences and Technologies of Lille, France 6 Sea Fisheries Institute, Gdynia, Poland 7 Tubitak, Marmara Research Center, Gebze, Turkey 8 IMAR, University of Algarve, Portugal 9 Ministry of Ecology and Natural Resources of the Azerbaijan Republic 10 Institute of Chemistry of State concern “Turkmenhimiya”, Turkmenistan