Zayıf nitelikli kentsel gri suyun karakterizasyonu ve analizi

World population is about 7.5 billion today and according to the estimations of UNDP, about 31% of this population will be added to existing population in less than 40 years. Inadequacy of natural sources and disability of meeting needs of rising population are two main problems that the world is already facing today. Water is one of those basic needs, however 1.1 billion people have no access to safe water at this time. As a result, sustainable use of available sources is gaining importance everyday, as sustainability will lead to ability of using the same sources for longer periods. Today, domestic wastewater is considered as one of the most popular water source after being treated properly. On the other hand, new domestic wastewater management concenpts are being proposed to be able to use domestic wastewater in the most efficient way. One of those management concenpts, segregation of domestic wastewater streams, can generally be done in two ways as two (grey water/black water) and three (grey water/yellow water/brown water) components, also known as EcoSan (Ecological Sanitation) streams. Grey water is the stream including the water generated from baths, showers, wash basins, washing machines, sinks and dish washers and other streams are generated from toilets. In both segregation applications, grey water stream will stay similar in terms of quantity and quality. Grey water itself can be segregated into two fractions as light grey water and dark grey water. Light grey water fraction refers to grey water generated from bath/shower and wash basins, while washing machine, sink and dish washer grey water are called dark grey water. Light grey water fraction has lower pollution potential and can be treated easier as compated to dark grey water. Grey water is considered as a valuable water source as it constitutes about 75% of total conventional domestic wastewater volume with lower pollution potential compared to conventional domestic wastewater volume. Due to its high volume and lower pollution potential, grey water is an attractive water source. Grey water is generally reused for irrigation and toilet flushing at this time, on the other hand it is a source that can be returned to almost any point of the water cycle after treated properly. In this study, a year-round monitoring was done to characterize raw hotel grey water countinuously and systematically. Additionally, a university student residence hall grey water was sampled and analyzed when possible. Both buildings were collecting grey water from bath/showers and wash basins. Effluents of membrane bioreactors (MBR) employed for grey water reclamation in those buildings were monitored. During analyses, organic matter, suspended solids, nitrogen and phosphorus concentrations were investigated. In hotel, microbiological analyses were carried out to observe the change in microbiological quality in grey water cycle. Also in toilet reservoir of one of the guest rooms where the grey water is reused, microbiological analyses were done to control possible regrowth of microbiological indicators. In student residence hall, microbiological analyses were carried out with raw grey water and treated grey water. Indicators analyzed were Total Coliforms, Fecal Coliforms, Escherichia Coli and Enterococci. In addition to those, in the light of the data generated in this work, the importance of physicochemical treatment of grey water was comprehended and preliminary treatment trials with sand filtration and membrane filtration were carried out. Also, as one of the major reuse areas of grey water is irrigation, preliminary plant trials were carried out with pepper seedlings. The results of this study revealed that even if the sources of grey water were the same in buildings that were monitored, grey water characteristics were not similar. Grey water generated from the hotel had lower pollution potential compared to grey water generated from the university student residence hall. On the other hand, grey water analyzed had lower pollution potential compared to weak conventional domestic wastewater. Year-long monitoring results of hotel grey water did not show a trend based on the seasonal factors. Also, no trend was observed in grey water quality in different days of the week. Apart from physical and chemical parameters investigated, the microbiological indicator concentrations were high in raw grey water and those concentrations were comparable to weak and intermediate strength conventional domestic wastewater sometimes, which makes monitoring of microbiological indicators a priority for grey water management. Average effluent quality of MBRs treating grey water met the requirements of water reuse standards all around the world. Even though the microbiological indicator concentrations were high in raw grey water, once grey water generated from the hotel and the university student residence hall were treated by MBRs properly, the effluents were free of those indicators. Results of preliminary physical treatment trials revealed that success of those systems investigated were highly dependent on the raw grey water characteristics. Particulate organic matter removal efficiencies of sand filtration and membrane filtration increased with decreasing sCOD/COD and sBOD5/BOD5 ratios, as the decrease in these ratios indicate high particulate organic matter content. Preliminary plant trials on pepper seedlings revealed that grey water was at least as successful as tap water for irrigation.