Domestic wastewater generation and characterization in Turkey

Abstract

It's necessary to perform a study for the determination of the characteristics and formation of the wastewater in the country in general in order to solve the wastewater problem in our cities with the lowest possible cost by using the most convenient technology available in the country. The result of the study should put forward the properties and quantities of the wastewater characteristics, which have to be determined as people's standards and living style in Turkey. In principle, this wastewater characteristic has to be utilized in the design of all wastewater treatment plants to be built. If there does not exist standardization on the formation and characterization of wastewater in our country, it would be necessary to use the data given in the literature in the design. Considering the investment amounts or operational costs, it becomes also difficult to say that wastewater treatment plants built with these data are the most convenient solutions. Besides the wastewater formation and characterization, there also does not exists any standardization on the design method of the wastewater treatment plants with respect to populations and pollution levels. Therefore, considering the variable populations of around 3,000 municipalities do not have a wastewater treatment plant in Turkey, the determination of the treatment method for each of the population range based on optimum costs and its application provides most convenient use of the financial resources which are already limited. Optimizations of all planned wastewater treatment plant both investment and operation cost is highly depending on very basic information which is municipal wastewater amount and characterization. Therefore it will be very helpful to create a data bank which is fed back with necessary operational data provided from all constructed wastewater treatment plants in addition to new data supplied by measurement that is taken for a new wastewater treatment plan. Everybody who is dealing with planning or execution of a wastewater treatment plant has to access this data bank before studying applicable process alternatives to decide the most economical one. During feasibility stage engineers has to know amount of municipal wastewater in addition to industrial discharge if there is. They also have to evaluate seasonally flowrate fluctuations observed especially in combined sewerage system come from storm water. It is also very important to execute very detailed wastewater analysis program during feasibility stage for defining the right wastewater characteristics which are essential data for sizing the selected wastewater treatment plant. In this study, data gathered from domestic wastewater treatment plants located in certain districts of Turkey and monitored for a long period, compared within the similar researches carried out in various countries related with wastewater characterization and waste-water amount versus water use. The wastewater amount and characterization related to the population is determined for a new treatment plant in Turkey. In Turkey most of the cities do not have plastic or ductile pipes for water supply system network. Therefore 40-45% of produced drinking water is lost in this network without reaching the end users. That is very big ration when it is compared in Europe. Recently some of the Greater Municipalities are started to change the existing distribution system pipes from asbestos to ductile or plastic. So that in Turkey, real amount of municipal wastewater should not be estimated based on drinking water served per capita. It is much better to measure rather than estimate it. Besides the leakage in the drinking water distribution network there is considerable amount of leakage in the wastewater collection system. Beside leakages, infiltration also has to be considered most of the cases in Turkey, for determining the wastewater amount. If there is not any measurement for infiltration it can be taken as 20% generally. Wastewater characterization is not also measured or estimated correctly most of the cases for designing a treatment plant. Therefore some of the existing wastewater treatment plant is larger that has to be. The reason was leak of the information about wastewater characteristics. Because of that most of the cases it is assumed that 60 gr BOD5 per capita which is normally 40-45 gr in realistic situation for most of the big cities. Because socioeconomic conditions are not good enough when compared with EU. It is clear that when treatment plant is designed based on unrealistic wastewater amount and characterization, the size will be larger. Unfortunately Turkey does not have enough financial sources for environmental investment. Therefore the limited economic sources must be used as good as possible. So that identifying of unit wastewater generation in addition t wastewater characterization is essential.

Özet

Kentlerimizdeki atıksu sorununun ülke sınırları içinde en uygun teknolojiyi kullanarak, minimum maliyetle çözülebilmesi için, öncelikle Türkiye 'de kişi başına oluşan evsel atıksuyun miktarının ve özelliklerinin tespiti için sağlıklı bir çalışma yapılması gereklidir. Planlanan tüm atıksu arıtma tesislerinin yatırım ve işletme giderlerinin optimizasyonu bu basit ama çok önemli verinin elde edilebilmesiyle çok yakından ilişkilidir. Bu nedenle mevcut tesislerin işletme kayıtlarından alınan ölçüm sonuçları ile arıtma tesisi olmayan bölgelerimizde yapılacak tüm yeni ölçümlerin bir veri bankasında toplanması, planlama ve tasarım ile sorumlu olan herkesin bu veri bankasına ulaşabilmesinin sağlanması çok önemli bir gelişme olacaktır. Evsel atıksu arıtma tesislerinin yapım aşamasının ilk adımı olan fizibilite çalışmasıdır. Bu çalışma sırasında, evsel atıksu miktarının, eğer varsa endüstriyel deşarjların debisinin ölçülmesi, birleşik kanal sisteminin bulunması durumunda yağmur suyunun etkisinin belirlenmesi sağlanmalıdır. Ayrıca, evsel ve endüstriyel atıksu karakterizasyonunun yapılması, seçilecek atıksu arıtma tesisinin hedeflenen deşarj standartlarına uygun olarak tasarlanması için büyük önem taşır. Bu çalışmada, Türkiye 'deki bazı büyük evsel atıksu artıma tesislerinden, uzun süreli izleme sonucu temin edilen atıksu karakterizasyonu ve su kullanımına karşı atıksu oluşumu ile ilgili bilgiler verilmiştir. Ayrıca elde edilen bu veriler aynı konuda, başka ülkelerde yapılmış olan çalışmalar ile karşılaştırılmıştır. Elde edilen ve literatürdeki diğer bulgularla birlikte değerlendirilen bu verilerle, Türkiye 'de yapılması planlanan yeni bir atıksu arıtma tesisi için kullanılabilecek, nüfusa bağlı atıksu oluşumu ve karakterizasyonu için kullanılabilecek tutarlı veriler önerilmiştir.