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Solar radyasyon (SR), enerji dönüşümü, meteoroloji, tarım ve hayvancılık ile ilgili çalışmalar için önemli bir parametredir. Solar radyasyonun belirlenebilmesi için gereken alıcıların tüm noktalar için temin edilememesinden dolayı bu parametreyi çeşitli yöntemlerle tahmin edilebilir. Bu çalışmada, Türkiye’nin aylık ortalama solar radyasyon değerleri (kWsa/m²) M5 model ağacı (M5-tree), sezgisel regresyon tekniği kullanılarak MATLAB platformunda tahmin edilmiştir. Solar radyasyon komşu ölçüm istasyonlarına ait konum bilgileri ve periyodiklik bileşeni olan ay değerleri kullanılarak tahmin edilmiştir. Modellerde kullanılan 2004-2018 yıllarını barındıran solar radyasyon verileri Meteoroloji Genel Müdürlüğü’nden temin edilen ve uydu tabanlı hibrit bir model olan HELIOSAT model verileridir. Çalışmada Türkiye’nin 81 iline ait ölçüm istasyonları kullanılmıştır. 81 istasyondan alınan 12 aylık verilerin %75’i eğitim sürecinde kullanılırken %25’i test sürecinde kullanılmıştır. Rastgele seçilen test istasyonlarından elde edilen solar radyasyon tahminleri gözlenen verilerle karşılaştırılmıştır. Bu karşılaştırmalarda kullanılan yöntemler, Karekök Ortalama Karesel Hata (KOKH), Ortalama Mutlak Hata (OMH), Ortalama Mutlak Bağıl Hata (OMBH) ve Determinasyon Katsayısı (R2) yöntemleridir. Sonuç olarak solar radyasyonun tahmin edilmesinde makine öğrenmesi tekniği kullanılarak elde edilen tahminler 4 farklı hata kriteri yöntemiyle karşılaştırılmıştır. Bu sayede makine öğrenmesi algoritmalarının literatürde yer alan kabul görmüş yöntemlere göre daha kolay uygulanabileceği ve alternatif bir yöntem olabileceği ispatlanmaya çalışılmıştır.

This study was conducted to investigate the effect of initial pH, current density, and electrolysis time on process performance in terms of decolorization and chemical oxygen demand (COD) removal from disperse dyebath wastewater (DDW) by mono-polar parallel laboratory scale electrocoagulation (EC) process. COD reduction of 51.3% and decolorization of 92.8% were obtained with operating cost of 0.19 €/m treated wastewater for Al-Al electrode pair, while 90.5% of decol-orization and 49.2% of COD reduction were obtained with operating cost of 0.203 €/m treated wastewater for an Fe-Fe electrode pair. The amount of sludge production were highly related to type of the electrode materials. At the3 optimum conditions, the amount of sludge produced were 0.18 kg/m and 0.28 kg/m for Al-Al and Fe-Fe electrode pairs, respec-tively. High decolorization can be explained by the hydrophobic nature of the disperse dye, while limited COD removal3 3 was observed due to the high dissolved organic matter of the DDW based on auxiliary chemicals. Energy, electrode, and chemical consumptions and sludge handling were considered as major cost items to find a cost-effective and sustainable solution for EC. The contribution of each cost items on operating cost were determined as 10.0%, 51.1%, 30.5% and 8.4% for Al-Al, and they were also determined as 9.0%, 38.0%, 40.5% and 12.5% for Fe-Fe, respectively. COD reduction and decolorization were fitted to first-order kinetic rule.

North Atlantic Oscillation (NAO) occurring on the North Atlantic Ocean affects hydrologic parameters such as temperature and precipitation in the region where temperature differences occurring on the ocean surface are transported by ocean currents. These effects and the increasing demand for water resources in recent years have made it necessary to use the limited water resources in nature in the most appropriate way to meet the needs. In order to examine the change of water resources, homogeneity and trend analyzes are carried out. In this study, Spearman Rho test and Modified Mann-Kendall test, which takes into account autocorrelation, were applied for standardized NAO data published by the National Weather Service Climate Prediction Center and 12-month precipitation data (between 1961-2015) of 18 stations in the Black Sea region. The study was examined in 95% of the confidence interval. The SRho correlation test was applied to determine the relationship between NAO index and Black Sea Region precipitation. When the study results are analyzed, a weak negative trend was detected between the data of North Atlantic Oscillation and the precipitation data of 18 stations analyzed in the Black Sea Region.

Akarsu akımlarının tahmini havza ve taşkın yönetiminde oldukça önemlidir. Doğrusallık göstermeyen ve birçok parametreye bağlı olan hidrolojik olayların tahminleri oldukça zor bir konudur. Bu çalışmada Mersin Lamas Nehri aylık ortalama akım verileri kullanılarak Yapay Sinir Ağları (YSA), Destek Vektör Makineleri (DVM) ve Derin Öğrenme (DÖ) optimizasyonları kullanılarak akım modellemesi yapılmış ve karşılaştırılmıştır. Sonuçlar incelendiğinde problemin çözümünde en iyi yöntemin DÖ olduğu YSA ve DVM yöntemlerinin ise buna göre daha başarısız sonuçlar verdiği gözlemlenmiştir. En iyi sonucu DÖ’ye ait 1 giriş modeli vermiştir (KOKH= 0.7647, OMH=0.7370, NSE=0.9724, OMBH=27.9326, R²=0.9962)., Estimation of stream flows is very important in basin and flood management. It is a very difficult topic to predict hydrological events that do not show linearity and depend on many parameters. In this study, streamflow modeling has been made and compared by using Artificial Neural Networks (ANN), Support Vector Machines (SVM) and Deep Learning (DL) optimizations using monthly average streamflow data of Mersin Lamas River. When the results are examined, it has been observed that the best method in solving the problem is ANN and SVM methods, which give more unsuccessful results. Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), Nash Sutcliffe model Efficiency coefficient (NSE), Mean Absolute Relative Error (MARE) and Coefficient of Determination (R2) were used as comparison criteria. 1 input model of DL gave the best result (RMSE= 0.7647, MAE=0.7370, NSE=0.9724, MARE=27.9326, R²=0.9962).

Reactive dyestuff is commonly used in the textile industry. Reactive dyebath wastewater (RDW) was treated with a batch, monopolar, parallel lab scale electrocoagulation process (EC) having 0.042 m2 effective electrode area. The effects of process parameters, such as initial pH, current density and electrolysis period on COD and color removal efficiency, were investigated by using response surface methodology (RSM). At the optimal conditions, 85.8% color and 76.9% COD removal were obtained with 1.84 €/m3 operating cost for Al electrode, while 92.0% decolorization and 80.9% COD removal were obtained with 1.56 €/m3 operating cost for an iron electrode. The iron electrode was found superior to aluminum as a sacrificial anode material in terms of COD and color removal with low cost. The cost of electrical energy, electrode, and chemical consumptions for electrocoagulation were considered to find an optimum and feasible solution. As a result, the operating cost consists of approximately 2% for energy, 28% for electrode and 70% for chemical consumption for both electrodes. Based upon the data, it is clearly seen that operating cost covers mostly for HCI to adjust pH due to the high pH and alkalinity of RDW, which was neglected in many studies. The first-order reaction kinetics with a higher slope for the color were well fitted, resulting in faster color removal than that of COD for both electrodes.

Doğu Karadeniz Bölgesi Türkiye’nin en çok yağış alan bölgesidir. Bu nedenle sıcaklık, yağış gibi meteorolojik parametrelerdeki değişimler bölgedeki hayatı büyük ölçüde etkilemektedir. Bu değişimlerin aşırı yağışların etkisi ile taşkın veya giderek artan sıcaklıkların etkisiyle ortaya çıkan kuraklık gibi insan hayatını ve bölgedeki üretimi etkileyerek sıcaklık ve yağış değişkenleri üzerinde meydana gelen değişikliklerin önemini gözler önüne sermektedir. Bu değişiklikleri tespit etmek amacıyla birçok parametrik ve parametrik olmayan yöntem geliştirilmiştir, bu yöntemlerin başında trend analizleri gelmektedir. Bu çalışmada Meteoroloji Genel Müdürlüğü’ne ait Giresun, Trabzon, Rize, Artvin, Gümüşhane, Bayburt illerinde bulunan 6 istasyondan elde edilen 1960-2016 yılları arasını kapsayan 57 yıllık sıcaklık, buharlaşma, rüzgar ve yağış verileri üzerinde %95 güven aralığında gerçekleştirilen trend analizlerinde parametrik bir yöntem olan Lineer Trend yöntemi ve parametrik olmayan Modifiye Mann-Kendall yöntemi kullanılmıştır. Bu çalışmanın sonucunda Lineer Trend yöntemi ve Modifiye Mann-Kendall yönteminden elde edilen sonuçların %86.1-97.22 oranında uyuştuğu saptanmıştır. Sonuçlar olarak incelendiğinde sıcaklık ve yağışların artan yönde eğilim gösterdiği, rüzgarların Trabzon istasyonunda artan, Rize ve Bayburt istasyonlarında azalan yönde anlamlı eğilimler gösterdiği tespit edilmiştir. Buharlaşma verileri ise Bayburt istasyonunda azalan, Gümüşhane ve Trabzon istasyonlarında artan bir eğilim göstermektedir., The Eastern Black Sea region is the rainiest region of Turkey. Therefore, changes in temperature, precipitation, etc., affect life in the region to a great extent. These changes show the importance of changes in temperature and precipitation variables by affecting human life and production in the region, such as flood caused by excessive precipitation or droughts caused by global warming. In order to detect these changes, many parametric and non-parametric methods have been developed. In this study trend analyzes were applied on 57 (1960-2016) years temperature, winds, evaporation and precipitation data of 6 stations in Giresun, Trabzon, Rize, Artvin, Gümüşhane, Bayburt provinces belonging to Turkish State Meteorological Service. Study was performed in 95% confidence interval. As a result of this study, the results obtained from Linear Trend method and Modified Mann-Kendall method were found to be 86.1-97.22 % concordant. When the results of the Eastern Black Sea Region are examined, it is observed that temperature and precipitation are showed in increasing direction, winds showed significant tendencies in the direction of increasing in Trabzon station and decreasing in Rize and Bayburt stations. Evaporation data showed decreasing trend in Bayburt station and increasing trend in Gümüşhane and Trabzon stations.

The digital elevation model (DEM) is the name given to a digital structure used to indicate the surface. Determination of features such as elevation, basin slope and basin area are very important in engineering applications. These properties are determined by the DEM and their power to represent accuracy or truth is vital in engineering applications. In addition to the latitude (X), longitude(Y) coordinate information, altitude information is required, and intermediate values are determined by different methods for DEM. In this study, Mert River Basin Samsun (Turkey) was chosen as the application area. Heights are estimated from X, Y coordinate information. Three different Artificial Neural Networks, IDW and Kriging methods were used. Artificial Neural Networks (ANN) were analyzed with three different inputs. These are: (i) x coordinate information; (ii) y coordinate information; (iii) It is in the form of x and y coordinate information and are used Radial Based Artificial Neural Network, Multilayer Artificial Neural Network and Generalized Artificial Neural Network. X and Y coordinate information was used in IDW and Kriging interpolation methods. Results were evaluated using Coefficient of Determination (R²), Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) as comparison criteria. According to the modeling results: It was observed that the results of all methods reached a sufficient level of accuracy. Kriging method was found to be the most successful model, followed by IDW and ANN.

Sonication is a well-known sludge pretreatment technique with the advantages of simple operation and high efficiency. However, it is an energy-intensive process. Hence, it is very important to predetermine its sludge disintegration efficiency at varying pretreatment conditions in order to minimize the ultrasonic energy consumption. In this study, it was found that the ultrasonic sludge disintegration occurred in two stages: rapid and subsequent slow disintegration stages. For this reason, it was aimed to develop a simple and accurate mathematical model to describe the two-stage sludge disintegration as a function of pretreatment conditions. Sludge concentration and ultrasonic density along with sonication period were involved in this model as independent variables. It was determined that the mathematical model can predict accurately the degree of sludge disintegration. Thus, the proposed model was seen to be very useful for evaluating the disintegration efficiency and/or for process design using the operating parameters under different conditions.

One of the most serious problems encountered in biological wastewater treatment processes is the production of waste activated sludge (WAS). Sonication, which is an energy-intensive process, is the most powerful sludge pre-treatment method. Due to lack of information about the combined pre-treatment methods of sonication, the combined pre-treatment methods were investigated and it was aimed to improve the disintegration efficiency of sonication by combining sonication with alkalization and thermal pre-treatment methods in this study. The process performances were evaluated based on the quantities of increases in soluble chemical oxygen demand (COD), protein and carbohydrate. The releases of soluble COD, carbohydrate and protein by the combined methods were higher than those by sonication, alkalization and thermal pre-treatment alone. Degrees of sludge disintegration in various options of sonication were in the following descending order: sono-alkalization > sono-thermal pre-treatment > sonication. Therefore, it was determined that combining sonication with alkalization significantly improved the sludge disintegration and decreased the required energy to reach the same yield by sonication. In addition, effects on sludge settleability and dewaterability and kinetic mathematical modelling of pre-treatment performances of these methods were investigated. It was proven that the proposed model accurately predicted the efficiencies of ultrasonic pre-treatment methods.

Coking wastewater contains high a concentration of refractory and toxic compounds to be treated before being discharged into the environment. The water quality usually cannot meet the discharge limits after conventional biological treatment processes. This article initially investigated the treatability of coking wastewater with conventional and modified Fenton processes for advanced treatment of coking wastewater. Based on the experimental results, up to 86% of chemical oxygen demand (COD) and 99.5% of phenol removals were achieved by the conventional Fenton process at original pH 7.8 within 60 min. pH adjustment was not performed due to the sudden drop in the original pH value, after the addition of Fenton's reagents. A modified Fenton process yielded comparable COD (82%) and phenol (98.5%) removals within 120 min at pH 3.0. The optimal operating conditions were determined as [Fe2+] = 300 mg/L, [H2O2] = 4000 mg/L, and pH = 7.8 for a conventional Fenton process, and [Fe0] = 300 mg/L, [H2O2] = 4500 mg/L, and pH = 3 for a modified Fenton process. © 2011 American Institute of Chemical Engineers Environ Prog, 32: 176-180, 2013

The aim of this study was to investigate the effectiveness of chemical oxidation by applying ozonation, combination of ozone and hydrogen peroxide and Fenton's processes for decolorization and residual chemical oxygen demand (COD) removal of biologically pretreated pulp and paper industry effluents. The batch tests were performed to determine the optimum operating conditions including pH, O3, H2O2, and Fe2+ dosages. H2O2 addition reduced the reaction times for the same ozone dosages; however combinations of ozone/hydrogen peroxide were only faintly more effective than ozone alone for COD and color removals. In the Fenton‘s oxidation studies, the removal efficiencies of COD, color and ultraviolet absorbance at 254 nm (UV254) for biologically treated pulp and paper industry effluents were found to be about 83, 95, and 89%, respectively. Experimental studies indicated that Fenton oxidation was a more effective process for the reduction of COD, color, and UV254when compared to ozonation and ozone/hydrogen per...

Treatment of three wastewaters and two acid dye solutions by ozonation with varying ozone dose, initial pH, and initial dye concentration were examined. Ozonation of all the wastewaters were shown to be pseudo-first-order reaction with respect to color, chemical oxygen demand (COD) and dissolved organic carbon (DOC). Increasing ozone dose increased the removal of color, COD, and DOC, as well as decreased ozone consumption ratio, and increased apparent rate constants. Ozonation was more successful at decolorization than the removal of COD and DOC or augmentation of biodegradability. Increasing initial dye concentration increased the ozone consumption and decreased the rate constant. Color removal efficiencies for different ozone dose application were in the range of 60-91% for sample A (dye bath effluent), and 70-96% for sample B (plant effluent). For sample A, COD and DOC removal efficiencies at several ozone dose applications were between 13-22 % and 8-13%, respectively. For sample B, they were between 11-33% and 6-15% respectively. Increasing pH could expand the efficiency of ozone slightly. Ozone consumption per unit color, COD and DOC removal at any time was found to bealmost the same whereas the applied ozone dose was different at a constant pH. Ozonation increased the biochemical oxygen demand (BOD,) of sample A and B 1.22 and 1.37 times by consuming 300 and 225 mg ozone, respectively. Ozonation of acid dyes was a pseudo-first order reaction with respect to dye. Increases in dye concentration raised specific ozone consumption. Specific ozone consumption for Acid Red 183 (AR-183) dye solution with 50 mg l(-1) of concentration rose from 0.32 to 0.72 mg-O3 per mg dye decomposed as the dye concentration was increased to 500 mg l(-1).

In this study, joint operation of several small wastewater treatment plants (SWWTPs) by the same operation company is proposed to avoid operational problems such as unqualified personnel, inadequate maintenance and laboratory services. Some case studies from Antalya province of Turkey are presented. Several SWWTPs are operated by the companies formed with the proportional shares of the owners such as ALTAS and TURAS. The performance data of the five treatment plants operated by ALTAS and two treatment plants operated by TURAS are presented. The status of wastewater treatment with emphasis on the small sized plants is also presented and evaluated. The percentage of small settlements served with sewer and wastewater treatment facilities is very low (3%) indicating that high volumes of investment are needed to increase the level of service to those of the developed countries. At present, the total number of the treatment plants in Antalya region is 409 with capacities ranging from 73 to 175 m3d-1. Package activated sludge type SWWPs built especially in the coastal regions meet the local effluent standards.

The Golden Horn has experienced severe pollution due to uncontrolled domestic and industrial wastewater discharges until recent years. A restoration project has been developed by our universities, upon a request from Istanbul Metropolitan Municipality. Two principal alternatives for the dredging and disposal of the bottom sediments were considered: disposing on the land and disposing in the sea. Both of these alternatives include several sub-alternatives. Characterization of the sediment quality is crucially important for selecting the best alternative considering the cost, environmental impact and public acceptance. However, only a few and rather old studies were present with which it was not possible to get a comprehensive information on the critical sediment characteristics. Therefore, the aim of this study was determination of spatial distribution of sediment characteristics. The project area, at which the sediment quality determined, covers the part of the Golden Horn remaining at the upstream of Valide Sultan Bridge. The number of sampling stations were thirteen and the sediment samples were collected from 0.0m, 5.0m and 10.0m from the bottom surface. The following parameters were measured on each sample: Total solids, organic matter, total phosphorus, TKN, oil and grease, total sulphur, and sediment oxygen demand (SOD). Sediment oxygen demand parameter was further divided into three fractions, namely, biological (SOD-B) and chemical (SOD-C). Average organic content of the bottom sediment was around 10% while ammonia and sulfur exhibit very high levels. It is found that the bottom sediment is well stabilized with very low organic content below 5.0m from the bottom surface. It can be said that, removing the upper 5m of the bottom sediment will be enough for creating a relatively stable bottom surface which will cause oxygen depletion in the overlaying water at acceptable levels. High SOD values of the bottom sediment makes the alternatives considering disposal in the Marmara Sea and Black Sea inapplicable. High SOD-C values, especially, indicate that the sediment will cause a tremendous reduction in the oxygen concentration in a very short time at any marine environment, and even it may create anaerobic conditions. Therefore, disposal of dredged sediment into abandoned mines 4km from the Golden Horn by a pressure pipeline has been chosen as the best applicable alternative.

The aim of this study was to investigate the effectiveness of chemical oxidation by applying ozonation, ozonation with hydrogen peroxide and Fenton's processes for decolorization and residual COD removal of biologically pretreated baker's yeast industry (BYI) effluents. Baker's yeast industry effluents characterizing with high COD, TKN, dark color, and non-biodegradable organic pollutants. The batch tests were performed to determine the optimum operating conditions including pH, O3, H2O2, and FeSO4 dosages, molar ratio of Fe2+/H2O2 and reaction time. It was noticed that H2O2 significantly reduced the reaction times for the same ozone dosages: however, COD and color removals were not remarkable. In the Fenton's oxidation studies, the removal efficiencies of COD and color for 30 min reaction time for three different types of BYI effluents were found about 86 and 92%, respectively. Experimental results of the presented study have clearly indicated that the Fenton's oxidation technology is capable to fate almost all parts of the organics which consist of both soluble initial and microbial inert fractions of COD for baker's yeast effluents. Effluents from the Fenton's oxidation process can satisfy effluent standards for COD and color in general.

In this study, the effect of applied ozone dose and pH on color removal from textile wastewater was studied. A lab-scale ozonation system was used in the experiments. When the applied ozone dose increased, the color removal efficiency and the rate constants increased, whereas ozone utilization ratio decreased. On the other hand, increasing the pH increased color removal efficiency and ozone consumption but decreased specific ozone dose. By using the experimental results, a new model has been developed to determine the required ozone dose for the removal of color. By means of this method, it was possible to determine the required ozone dose for reducing the amount of color up to desired levels. Experimental results and the model predictions were in good agreement not only for textile wastewater but also for different industrial effluents. Some parameters affecting ozone utilization such as pH, could also be incorporated into the model.

The purpose of this study was to investigate an effective treatment system which can be applicable to treat opium alkaloid industry (OAI) effluents characterised with high COD, TKN, dark color and non-biodegradable organic pollutants. In the first phase of the study, lab-scale anaerobic (UASBR) + aerobic (SBR) treatability studies were carried out on opium processing industry effluents. Effluent CODs from the two staged biological treatment system were relatively high (∼700 mgl−1) and additional post treatment was required. Physico-chemical treatability studies previously carried out on the effluent of opium alkaloid wastewater treatment plant, were not effective in removing residual COD and color. In the second phase of the study, the refractory organics causing higher inert COD values in the SBR effluent were additionally treated by using Fenton's Oxidation. The batch tests were performed to determine the optimum operating conditions including pH, H2O2 dosage, molar ratio of Fe2+/H2O2 and reaction time. It was found that removal efficiencies of COD and color for 30 minutes reaction time were about 90% and 95%, respectively. The ratio of H2O2/FeSO4 was determined as 200 mgl−1/600 mgl−1 for the optimum oxidation and coagulation process at pH 4. Experimental results of the present study have clearly indicated that the Fenton's oxidation technology is capable to treat almost all parts of the organics which consist of both soluble initial and microbial inert fractions of COD for opium alkaloid industry effluents. Effluents from the Fenton's Oxidation process can satisfy effluent standards for COD and color in general.

The aim of this study is to investigate the effect of some operational parameters on the efficiency of ozonation and Fenton's process for decolorization and COD removal. Acid Red 337 and Reactive Orange 16 dye solutions and the effluents of acid and reactive dye-bath effluents were used in the experiments. The influence of ozone dose and pH for color and COD removal from the wastewater were studied. Increasing the ozone dose increased the rate constants, and color and COD removal efficiencies. Ozone consumption ratio per unit color and COD removal at any time was found to be almost the same while the applied ozone dose was different. pH did not significantly affect color and COD removal from the wastewater by ozonation. In spite of having high color removal efficiencies (60–91%), limited COD removal efficiencies between 9–17% at 30 minutes ozonation time were obtained. In the Fenton oxidation experiments, the effects of pH, temperature, dosage of ferrous sulfate and hydrogen peroxide, and the proper ratio of Fe(II)/H2O2 were studied. The result indicates that up to 99% color removal and 82% COD removal can be obtained by Fenton's oxidation. While Fenton's oxidation was greatly affected by the pH value, temperature of wastewater did not significantly affect the Fenton process for color removal. Increasing the dose of both hydrogen peroxide and ferrous sulfate enhanced the removal efficiencies of color and COD. Suitable ratios of Fe(II)/H2O2 were found to be between 0.5 and 0.83.

The ozonation of wastewater supplied from a treatment plant (Samples A and B) and dye-bath effluent (Sample C) from a dyeing and finishing mill and acid dye solutions in a semi-batch reactor has been examined to explore the impact of ozone dose, pH, and initial dye concentration. Results revealed that the apparent rate constants were raised with increases in applied ozone dose and pH, and decreases in initial dye concentration. While the color removal efficiencies of both wastewater Samples A and C for 15 min ozonation at high ozone dosage were 95 and 97%, respectively, these were 81 and 87%, respectively at low ozone dosage. The chemical oxygen demand (COD) and dissolved organic carbon (DOC) removal efficiencies at several ozone dose applications for a 15 min ozonation time were in the ranges of 15–46% and 10–20%, respectively for Sample A and 15–33% and 9–19% respectively for Sample C. Ozone consumption per unit color, COD and DOC removal at any time was found to be almost the same while the applied ozone dose was different. Ozonation could improve the BOD5 (biological oxygen demand) COD ratio of Sample A by 1.6 times with 300 mg dm−3 ozone consumption. Ozonation of acid dyes was a pseudo-first order reaction with respect to dye. Increases in dye concentration increased specific ozone consumption. Specific ozone consumption for Acid Red 183 (AR-183) dye solution with a concentration of 50 mg dm−3 rose from 0.32 to 0.72 mg-O3 per mg dye decomposed as the dye concentration was increased to 500 mg dm−3. © 2002 Society of Chemical Industry

The results of membrane and ozonation experiments carried out on various agro-industry effluents including fermentation (baker's yeast), corrugated board, opium alkaloid and textile dying industries are presented. The experiments were performed using lab-scale membrane and ozonation reactors. Color removals were in the range of 80 to 99% for the membrane treatment studies. Ozonation experiments have shown that color removals in the range of 83 to 98% are possible for the investigated wastewaters. Final color levels were lower than 100 Pt-Co unit, which is quite acceptable aesthetically. The relative unit treatment costs of ozonation were about two times higher than membrane systems especially for very strong colored effluents including fermentation and opium alkaloid industries. The study has demonstrated that both membrane and ozonation technologies are viable options for color removal.

This paper presents pilot‐scale membrane treatment results performed on biologically treated effluents from fermentation industry and ozone oxidation on concentrates from the same membrane treatment system. The results obtained from the ultrafiltration (UF) and/or the reverse osmosis (RO) systems indicate that membrane treatment are very effective for COD, Color, NH3‐N and conductivity removal. Ozone oxidation of the membrane concentrates was tested to increase biodegradability of the wastes. The initial ratios of Biochemical oxygen demand (BOD5) to Chemical oxygen demand (COD) were increased significantly by applying chemicaloxidation with O3 and O3 + H2O2.

The aim of this study is to characterize the wastewater from an opium alkaloid processing plant and to evaluate alternative treatment techniques to upgrade an existing full-scale biological activated sludge treatment plant having problems of high residual COD and unacceptable dark brown color. In this content firstly, long term operational records of the two stage aerobic activated sludge treatment plant of the opium alkaloid factory located in Afyon province of Turkiye were evaluated. The operating results for the last three years were statistically analyzed and median and 95-percentile values were determined for the parameters including chemical and biological oxygen demand (COD and BOD5) and treatment efficiencies. Specific wastewater generation was found as 6.7 m3 per ton of the opium capsule processed. In the following stage of the study, three additional treatment processes were experimentally tested: anaerobic pretreatment, post treatment of aerobically treated effluents with lime and ozone. Pilot scale upflow anaerobic sludge blanket reactor (UASBR) experiments have demonstrated that about 70 percent of the incoming COD can be removed anaerobically. Chemical treatability studies with lime for the aerobically treated effluent have shown that about 78 percent color and 46 percent COD removals can be obtained with lime dosage of 25 gl−1. Post treatment of the effluents of the existing two stage aerobic treatment with ozone also resulted in significant color and COD reduction.

The individual and combined effects of alkaline and ultrasonic pretreatment on both physical and chemical properties and anaerobic biodegradability of waste activated sludge (WAS) were investigated comprehensively in this study. The experimental results showed that both disintegration and anaerobic biodegradability of WAS were significantly improved by the combination of alkaline and ultrasonic (sono-alkaline) pretreatment. Besides, it was determined that the hydraulic retention time in anaerobic digester can be shortened by half using this combined pretreatment. However, it was also determined that sono-alkaline pretreatment was not feasible economically due to its high energy requirement.

Sonication and thermalization can be applied successfully to disrupt the complex waste activated sludge (WAS) floc structure and to release extra and intra cellular polymeric substances into soluble phase along with solubilization of particulate organic matters, before sludge digestion. In this study, sonication has been combined with thermalization to improve its disintegration efficiency. It was aimed that rise in temperature occurring during the sonication of sludge was used to be as an advantage for the following thermalization in the combined pre-treatment. Thus, the effects of sonication, thermalization and sono-thermalization on physical and chemical properties of sludge were investigated separately under different pre-treatment conditions. The disintegration efficiencies of these methods were in the following descending order: sono-thermalization > sonication > thermalization. The optimum operating conditions for sono-thermalization were determined as the combination of 1-min sonication at 1.0 W/mL and thermalization at 80 °C for 1 h. The influences of sludge pre-treatment on biodegradability of WAS were experienced with biochemical methane potential assay in batch anaerobic reactors. Relative to the control reactor, total methane production in the sono-thermalized reactor increased by 13.6% and it was more than the sum of relative increases achieved in the sonicated and thermalized reactors. Besides, the volatile solids and total chemical oxygen demand reductions in the sono-thermalized reactor were enhanced as well. However, it was determined that sludge pre-treatment techniques applied in this study was not feasible due to their high energy requirements.

The treatability of a copper mine wastewater, including heavy metals, AMD, as well as flotation chemicals, with Fenton process was investigated. Fenton process seems advantageous for this treatment, because of Fe(2+) content and low pH of AMD. First, optimum Fe(2+) condition under constant H(2)O(2) was determined, and initial Fe(2+) content of AMD was found sufficient (120 mg/L for removal of chemical oxygen demand (COD) of 6125 mg/L). In the second step, without any additional Fe(2+), optimum H(2)O(2) dosage was determined as 40 mg/L. Fe(2+)/H(2)O(2) molar ratio of 1.8 was enough to achieve the best treatment performance. In all trials, initial pH of AMD was 4.8 and pH adjustment was not performed. Utilization of existing pH and Fe(2+), low H(2)O(2) requirements, and up to 98% treatment performances in COD, turbidity, color, Cu(2+), Zn(2+) made the proposed treatment system promising. Since the reaction occurs stepwise, a two-step kinetic model was applied and calculated theoretical maximum removal rate was consistent to experimental one, which validates the applied model. For the optimum molar ratio (1.8), 140 mL/L sludge of high density (1.094 g/mL), high settling velocity (0.16 cm/s) with low specific resistance (3.15 x 10(8)m/kg) was obtained. High reaction rates and easily dewaterable sludge characteristics also made the proposed method advantageous.

Black Sea riparian countries have committed to prevent, reduce and control pollution of the marine environment of the Black Sea from land-based sources in accordance with Article VII of the Bucharest Convention. Gathering information on the sources of pollution was one of the basic requirements of the Odessa Ministerial Declaration of the Black Sea countries. This paper presents a summary of the outcome of the studies conducted to fulfil this obligation. The aim of this study has been limited to the point sources of wastewater discharges including domestic as well as industrial discharges. The inputs through main rivers were also included in the scope. Solid wastes directly or indirectly discharged or dumped into the Black Sea were not included in this study. Diffuse sources, surface runoff (storm water) and air emissions were not included in the scope of the study. In this paper, total domestic, industrial and riverine pollution loads of the major pollutants such as BOD, TSS, TN and TP were presented for each of the six Black Sea riparian countries after compilation of the data. Rapid assessment techniques of WHO were adopted in the study to estimate the pollutant loads of the point sources. The major source of contamination to the Black Sea arises as a result of the inputs of contaminants from international rivers, especially the River Danube. The other international rivers are also crucial in the pollution of the Black Sea, although the River Danube is the dominant pollutant source. The fact that the total riverine input is about 85% of the total pollution load of BOD demonstrates the significance of the control of the riverine sources. Total pollution loads of each Black Sea country and their breakdown as domestic, industrial and riverine inputs were presented both in graphical and in tabulated forms. Furthermore, the contribution of the oil pollution and pollution exchange through straits (Kerch and Bosphorus Straits) are also given.

Evaluation of the industrial pretreatment plants in Istanbul Metropolitan area is presented. Out of 7899 industries located in Istanbul, 1420 of them require pretreatment to meet the discharge criteria. Currently, there are 532 pretreatment works which treat 82.6 percent of the industrial wastewaters. Discharge standards and the compliance monitoring system for the industrial wastewater discharges into the public sewers as applied by the Istanbul Water and Sewerage Administration are discussed. The performance data of the pretreatment plants are given based on the percent non-compliance and percent removal efficiency figures determined for different categories of industry. Problem areas in terms of industrial sector and in terms of quality parameters are identified.