Wastewater Treatment Plants In Turkey Research Articles

Abundance and characteristics of microplastics in an urban wastewater treatment plant in Turkey

Wastewater treatment plants (WWTPs) are considered one of the important sources of aquatic/terrestrial microplastic (MP) pollution. Therefore, the abundance and properties of MPs in the wastewater and sludge of an urban WWTP in Bursa Turkey were investigated. The amount, properties, and removal of MPs were evaluated. The results showed that the average abundance of MPs was 135.3 ± 28.0 n/L in the influent and 8.5 ± 4.7 n/L in the effluent, with a 93.7% removal rate, MP was removed and transferred to the sludge. The daily MP amount released in the aquatic environment is calculated as 525 million MPs, and the annual amount is 1.9 × 1011 MPs. The abundance of MPs in the sludge thickening and sludge filter cake is 17.9 ± 2.3 and 9.5 ± 2.3 n/g dry weight (dw), respectively. The sludge disposal amount of WWTP is 81.5 tons/day and the approximate amount of MP accumulated in the sludge per year is calculated as 2.8 × 1011 MPs. In wastewater and sludge samples, fragment dominant shape, black main colour, and 500–1000 μm sizes are the most common size. The main MP types in wastewater samples at the influent are polypropylene (PP, 36.8%), polyethylene (PE, 31.0%), polystyrene (PS, 11.8%), polyethylene terephthalate (PET, 8.0%), and polyamide (PA, 7.1%), at the effluent (PE, 33.0%), (PP, 52.5%), and (PS, 8.2%). In the sludge cake, the distribution is (PE, 40.8%), (PP, 27.6%), (PS, 18.7%) and (PET, 8.0%). The results of this study show that MPs are removed from wastewater with high efficiency by treatment processes and a significant amount accumulates in the sludge. Therefore, it is suggested that to integrate advanced treatment processes into urban WWTPs and use effective sludge disposal management practices to reduce the amount of MP released into the environment with effluent and sludge.

Environmental and techno-economic analysis of the integration of biogas and solar power systems into urban wastewater treatment plants

This study analyses the environmental and economic benefits of integrating renewable energy sources (RES), biogas and solar energy into urban wastewater treatment plants (WWTPs). The energy intensity (kWh/m3) of the selected 456 WWTPs in Turkey was evaluated according to type and treatment process. The energy intensity of primary WWTPs (0.066–0.335 kWh/m3) is lower than that of secondary (0.075–1.361 kWh/m3) and advanced WWTPs (0.147–0.988 kWh/m3). RES integration is investigated using energy system optimization software for a sample of 25 WWTPs. Six scenarios were developed based on different CO2 emission penalties (0 and 16 USD/ton) and prices for selling electricity to the grid (0.000, 0.050, and 0.133 USD/kWh) to demonstrate the impact of market-based instruments. RES integration is cost-effective for secondary and advanced WWTPs with a flow capacity above 1 million m3/y. Market-based instruments are found to significantly influence the decision to integrate, generate and use renewable electricity at WWTPs. The RES integration can meet up to 88% of the annual energy demand of the WWTPs at an electricity selling price of 0.133 USD/kWh. When no market-based instruments are implemented, RES generation can reach up to 23% of the WWTPs' annual energy demand while reducing CO2 emissions by 15%.

District heating and electricity production based on biogas produced from municipal WWTPs in Turkey: A comprehensive case study

In this paper, district heating (DH) potentials of the wastewater treatment plants (WWTPs) based on their biogas, electricity, and heat productions are considered. Two district heating scenarios are developed: (i) DH Scenario I which is based on both excess biogas storage of the WWTP and exhaust gas of the cogeneration with the actual power output, (ii) DH Scenario II which is based on the exhaust gas of the cogeneration with the increased power output using all the biogas produced. In DH Scenario I, it is found that 458 dwellings can be heated via the DH system proposed considering only the waste heat of the cogeneration. In addition, the natural gas consumption of 1112 dwellings with the same annual heating load can also be met using the purified biogas. In DH Scenario II, the electricity production could be increased to 1643 kWh by burning all the biogas produced in the cogeneration plant. In this scenario, the annual heating load of 755 dwellings in Gaziantep province can be covered using the waste heat in the DH system. The payback period for the DH Scenario I is calculated as 2.5 years, while for the DH Scenario II, it is obtained as 2 years.

Evaluation of Reuse of Wastewater in Agriculture in Turkey: Outbreak Perspective of Covid-19

The recent outbreak of novel coronavirus disease 2019 has become a public health emergency worldwide. The virus, SARS-CoV-2 is spread by human to human transmission via droplets or direct contact. Although there is no evidence of its transmission from wastewater, the virus has been discovered in wastewater. Recent studies showed that SARS-CoV-2 is very sensitive to oxidants such as chlorine. Therefore, disinfection units of treatment plants need to be operated to avoid virus existence in the environment. Moreover, the disinfection process is vital if treated water is going to be used in irrigation. More than one-third of the effluents of wastewater treatment plants in Turkey reaches to agricultural irrigation facilities. The majority of these waste water treatment plants do not have a disinfection unit. Agricultural areas irrigated with treated wastewater have a rich crop pattern in Turkey. Almost half of these agricultural areas used to grow raw-consumable products. Therefore, disinfection units need to be operated properly and the facilities without disinfection unit should be revised. Moreover, regulations are not comprehensive to prevent public health in terms of reuse of wastewater in agriculture in Turkey. There are one regulation and one standard available considering reuse of wastewater in irrigation but neither of them is not covering indirect reuse of treated wastewater in the downstream. Therefore, to prevent public health it is needed to update regulations to include indirect reuse of wastewater.

Environmental performances of the wastewater treatment plants: Green Index

The Green Index as a new indicator to determine the environmental performance has been developed in order to reduce the unfavourable environmental impacts of the wastewater treatment plants. The main aim of this study is to reveal the environmental performances of the wastewater treatment plants. An industrial and a municipal wastewater treatment plant in Turkey have been compared in terms of the Green Index. The results revealed that in August, for the municipal and the industrial wastewater treatment plants, CO2 emission values were 0.972 and 0.42 kg/h, respectively. N2O emissions were also 8.7 and 1.53 kg/h, respectively. CO2 emissions in September were with the values of 0.507 and 0.657 kg/h for the municipal and the industrial wastewater treatment plants, respectively and N2O emissions were 5.4 and 1.2 kg/h, respectively. The Green Index of industrial wastewater treatment plant was lower than the municipal one with the values of 1.13 and 1.36, respectively.

Occurence and Prioritization of Pharmaceutical Active Compounds in Domestic/Municipal Wastewater Treatment Plants

In this study, pharmaceutically active compounds (PhACs) were analyzed in the influent and effluent of a domestic wastewater treatment plant in Turkey and a municipal wastewater treatment plant in Germany and the toxicity of these wastewaters were estimated using a toxic unit (TU) approach. A total of 21 and 32 PhACs were detected in the domestic wastewater and the municipal wastewater, respectively. The TUs estimated for PhACs in municipal wastewater were higher than the TUs estimated for PhACs present in domestic wastewater. The levels of the anti-anxiety drug, oxazepam were estimated to be in the high risk category (HQ > 10) in both wastewaters. In bench-scale tests with ozonation, the removals of four PhACs in the municipal wastewater were investigated. At a dose of 2mg/L ozone, 97%-98% of diclofenac and carbamazepine were removed. The lowest removal rate at 71% was observed for metoprolol.

An integrated fuzzy QFD and TOPSIS methodology for choosing the ideal gas fuel at WWTPs

Increase of population, development of industry, environmental problems and continuous energy consumption in the world render renewable energy resources crucial. This paper focuses on multiple criteria decision making (MCDM) models for energy saving and using energy resources efficiently in order to maintain sustainable operations at wastewater treatment plants (WWTPs). An integrated fuzzy quality function deployment (FQFD) framework and technique for order preferences by similarity to an ideal solution (TOPSIS) selection algorithm is proposed. Fuzzy analytic hierarchy process (FAHP) is used to determine importance weights of attributes in MCDM model to avoid inconsistent results of crisp QFD analyses caused by the variability of human judgment. Fuzzy analytical network process (FANP) is used to consider both symmetrical and asymmetrical relationships between customer requirements (CRs) and engineering characteristics (ECs) for constituting internal and external correlation matrices in the house of quality (HOQ). The comprehensive weight vector of ECs is used as the weights of the selection criteria in the TOPSIS side of the integrated methodology. The proposed MCDM methodology is used for the goal of choosing the ideal gas fuel at WWTPs. Regarding to the results of application of the proposed MCDM model at a WWTP in Turkey, the most important EC regarding to the goal is hydrocarbons with the weight value of 0.32, while gas processing system with 0.21 is the second and impurities with 0.19 is the third EC. Biogas is chosen as the ideal gas fuel. In addition, natural gas is the second, liquefied natural gas is the third, compressed natural gas is the fourth and landfill gas is the fifth gas fuels in turn at the WWTP in Turkey.

An experimental examination of energy production from domestic-based waste water treatment sludge

In Turkey, treatment sludge that obtained from domestic wastewater and water treatment plants causes storage and disposal problems. In the current situation, there are 69 domestic wastewater treatment plants in Turkey and this corresponds to approximately 13% of the population. Total 500 thousand tons of treatment sludge is released from these treatment plants, annually. In the case of all municipalities establish a wastewater treatment plant in Turkey, approximately, 4 million tons of treatment sludge is projected to release in a year. Additionally, 3.6 million tons of treatment sludge will be obtained from the manufacturing industry. In other words, approximately 7.6 ↔ 106 tons of treatment sludge potential exists in Turkey and in the same amount of the storage area (7.6 ↔106m3) is needed for the storage of this treatment sludge, perennially. In this study, energy production from wastewater treatment sludge through the anaerobic method has been investigated and compared to the aerobic treatment method. Also, advantages and disadvantages of both methods have been introduced. In order to determine biogas production capacity from treatment sludge, some amount of sample sludge has been taken from the final sedimentation tank before belt press in a wastewater treatment plant and it has been experimentally analyzed.

Investigation of nonylphenol and nonylphenol ethoxylates in sewage sludge samples from a metropolitan wastewater treatment plant in Turkey

Nonylphenol ethoxylates (NPEOs) have drawn significant attention within the last decade for both scientific and legislative reasons. In Turkey, the Regulation Regarding the Use of Domestic and Urban Sludges on Land states a limit value for the sum of nonylphenol (NP), nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate (NP2EO) as NPE (NPE=NP+NP1EO+NP2EO). Unfortunately a standard method for the determination of these chemicals has not been yet set by the authorities and no data exists about the concentrations of NP and NPEOs in sewage sludge in Turkey. The aim of this study is to propose simple and easily applicable extraction and measurement techniques for 4-n-nonylphenol (4-n-NP), NP, NP1EO and NP2EO in sewage sludge samples and investigate the year round concentrations in a Metropolitan Wastewater Treatment Plant (WWTP) in Turkey.Different extraction techniques and GC/MS methods for sewage sludge were tested. The best extraction method for these compounds was found to be ultrasonication (5min) using acetone as the solvent with acceptable recovery of analytes suggested by USEPA and other studies. The optimized extraction method showed good repeatability with relative standard deviations (RSDs) less than 6%. The recovery of analytes were within acceptable limits suggested by USEPA and other studies. The limits of detection (LODs) were 6µgkg−1 for NP and NP1EO, 12µgkg−1 for NP2EO and 0.03µgkg−1 for 4-n-NP. The developed method was applied to sewage sludge samples obtained from the Central WWTP in Ankara, Turkey. The sum NPE (NP+NP1EO+NP2EO) was found to be in between 5.5µgkg−1 and 19.5µgkg−1, values which are in compliance with Turkish and European regulations.

Seasonal variation of diclofenac concentration and its relation with wastewater characteristics at two municipal wastewater treatment plants in Turkey

The pharmaceutically active compound diclofenac has been monitored during one year at separate treatment units of two municipal wastewater treatment plants (WWTPs) to evaluate its seasonal variation and the removal efficiency. Conventional wastewater characterization was also performed to assess the possible relationship between conventional parameters and diclofenac. Diclofenac concentrations in the influent and effluent of both WWTPs were detected in the range of 295–1376 and 119–1012ng/L, respectively. Results indicated that the higher diclofenac removal efficiency was observed in summer season in both WWTPs. Although a consistency in diclofenac removal was observed in WWTP_1, significant fluctuation was observed at WWTP_2 based on seasonal evaluation. The main removal mechanism of diclofenac in the WWTPs was most often biological (55%), followed by UV disinfection (27%). When diclofenac removal was evaluated in terms of the treatment units in WWTPs, a significant increase was achieved at the treatment plant including UV disinfection unit. Based on the statistical analysis, higher correlation was observed between diclofenac and suspended solids concentrations among conventional parameters in the influent whereas the removal of diclofenac was highly correlated with nitrogen removal efficiency.

Characterization and assessment of a large-scale domestic advanced wastewater treatment plant in Turkey

The paper presents new studies about the removal efficiencies and characterization of the Municipal Wastewater Treatment Plant (MWWTP) in Kayseri, Turkey, which is serving for 800,000 population equivalents with the capacity of 110,000 m(3)/day, between 2006 and 2009. Kayseri discharges its effluents to Karasu Creek that downstream joins the Kizilirmak river, the longest river in Turkey discharging into the Black Sea. Four years of operation data between 2006 and 2009 calendar years were obtained from KASKI General Directorate. Influent and effluent samples were collected daily and suspended solids (SS), chemical oxygen demand (COD), biochemical oxygen demand in 5 days (BOD(5)), total nitrogen (TN), and total phosphorus (TP) were measured, aiming to study the evolution of the removal efficiencies for each year. The following yearly mean removal efficiencies were performed in the treatment plant: 94%, 97%, 97%, 95% for SS; 94%, 96%, 95%, 95% for COD; 98%, 98%, 98%, 98% for BOD(5); 84%, 87%, 89%, 82% for TN; and 71%, 86%, 80%, 86% for TP, in 2006, 2007, 2008, and 2009, respectively. The performance of Kayseri MWWTP was given both in terms of influent and effluent quality and in comparison with the current legislation on discharge limits to the receiving body. During the studied period, mean concentrations in the effluent did not exceed the imposed limits, but sometimes, higher values were noticed for SS, TN, and TP. In conclusion, the plant performances concerning these parameters were excellent and Kayseri MWWTP was operating efficiently according to the conventional control parameters.

Co-digestion of the organic fraction of municipal solid waste with primary sludge at a municipal wastewater treatment plant in Turkey

Co-digestion of the organic fraction of municipal solid waste (OFMSW) and sewage sludge may be an attractive alternative for sustainable management of two separate waste streams produced in large amounts in all countries. This study evaluates calculation-based results of an anaerobic co-digestion process for primary sludge (PS) together with the OFMSW. The calculations were carried out for the anaerobic digester of Kayseri municipal wastewater treatment plant (in Turkey) presently digesting only PS. Two alternatives were proposed using different solid waste contents in co-digesters. For achieving the optimal solids content, some treated wastewater should be recycled to the inlet of the digesters. The municipal solid waste collection method characterized as mechanically sorted (MS-OFMSW; Option 1) is evaluated as well as a source sorted (SS-OFMSW) alternative (Option 2). Utilizing the energy produced by the existing sludge digester, only 30% of the internal energy demand at the wastewater treatment plant can be covered. The aim of this study is to evaluate how energy production would be increased by co-digestion of OFMSW and PS. The best operational condition considering organic loading rate, hydraulic retention time and energy generation could be attained at 10% digester solids content for both options. According to Option 1, almost 77% of the energy demand could be covered by co-digestion of MS-OFMSW and PS. Results indicated that almost 100% energy coverage can be obtained when co-digestion (Option 2) was performed according to SS-OFMSW and PS.

An investigation of agricultural use potential of wastewater sludges in Turkey – case of heavy metals

Landfilling is one of the most common methods that are used in the final disposal of sludge world wide, as well as in Turkey. However, increasing sludge quantities and limited landfilling areas make this method difficult to apply. The use of sludge in agriculture presents a possible alternative for disposal. However, it also poses some risks to be evaluated. In this respect, it is important to identify the heavy metal content of sewage sludges because of its adverse health effects. This study aims to determine the heavy metal contents of sludges and wastewaters from three different wastewater treatment plants in Turkey. The selection of plants was carried out according to the different treatment technologies applied to wastewater and sludge in those plants. Heavy metal analysis of sludges and wastewaters was conducted using a microwave assisted digestion procedure. After sampling and analysis, the results show that all the related metal concentrations are below the values that are set in the Soil Pollution Control Regulation of Turkey. However, in two of the three plants, Zn and Ni concentration should be tracked carefully.