Water quality and hydrogeochemical characteristics of the River Buyukmelen, Duzce, Turkey

Abstract

Abstract:The River Buyukmelen is located in the province of Duzce in northwest Turkey and its water basin is approximately 470 km 2 . The Aksu, Kucukmelen and Ugursuyu streams flow into the River Buyukmelen. It flows into the Black Sea with an output of 44 m 3 s 1 . The geological succession in the basin comprises limestone and dolomitic limestone of the Yılanlı formation, sandstone, clayey limestone and marls of the Akveren formation, clastics and volcano-clastics of the Caycuma formation, and cover units comprised of river alluvium, lacutrine sediments and beach sands. The River Buyukmelen is expected to be a water source that can supply the drinking water needs of Istanbul until 2040; therefore, it is imperative that its water quality be preserved.The samples of rock, soil, stream water, suspended, bed and stream sediments and beach sand were collected from the Buyukmelen river basin. They were examined using mineralogical and geochemical methods. The amount of suspended sediment in the River Buyukmelen in December 2002 was 120 mg l 1 . The suspended and bed sediments in the muddy stream waters are formed of quartz, calcite, plagioclase, clay (kaolinite, illite and smectite), muscovite and amphibole minerals. As, Co, Cd, Cr, Pb, Ni, Zn and U have all accumulated in the Buyukmelen riverbed sediments. The muddy feature of the waters is related to the petrographic features of the rocks in the basin and their mineralogical compositions, as most of the sandstones and volcanic rocks (basalt, tuffite and agglomerate) are decomposed to a clay-rich composition at the surface. Thus, the suspended sediment in stream waters increases by physical weathering of the rocks and water-rock interaction. Owing to the growing population and industrialization, water demand is increasing. The plan is to bring water from the River Buyukmelen to Istanbul's drinking-water reservoirs. According to the Water Pollution Regulations, the River Buyukmelen belongs to quality class 1 based on Hg, Cd, Pb, As, Cu, Cr, Zn, Mn, Se, Ba, Na C , Cl , and SO 2 4 ; and to quality class 3 based on Fe concentration. The concentration of Fe in the River Buyukmelen exceeds the limit values permitted by the World Health Organization and the Turkish Standard. Because water from the River Buyukmelen will be used as drinking water, it will have an adverse effect on water quality and humans if not treated in advance. In addition, the inclusion of Mn and Zn in the Elmali drinking-water reservoir of Istanbul and Fe in the River Buyukmelen water indicates natural inorganic contamination. Mn, Zn and Fe contents in the waters are related to geological origin. Moreover, the River Buyukmelen flow is very muddy in the rainy seasons and it is inevitable that this will pose problems during the purification process.

Spatial Assessment of Water Quality in Peripheral Rivers of Dhaka City for Optimal Relocation of Water Intake Point

“…This can quickly deplete the available oxygen and subsequently affect aquatic life. Also, when organic compounds decompose under low DO conditions, it can give rise to undesirable odors usually associated with septic or putrid conditions (Pehlivan and Yilmaz 2005).…”

“…These water quality parameters were selected because of their significance on aquatic life and human consumption (Pehlivan and Yilmaz 2005). This is elaborated in the section that follows (see Table 2 for Bangladesh Standards -taken from DoE 1991).…”

The effect of weathering in the Buyukmelen River basin on the geochemistry of suspended and bed sediments and the hyrogeochemical characteristics of river water, Duzce, Turkey

“…A study carried out in 2003 on the down Buyukmelen basin reported that the water quality class was quality class 3 for Fe in winter (Pehlivan and Yilmaz, 2005). When heavy metal content of the stream water in the Buyukmelen River basin in winter and summer were compared with the limit values stated by the Water Pollution Regulation of Turkey, it was found that the water quality of Asarsu stream and the Buyukmelen River in winter is water quality class 4 for Al and water quality class 3 for Fe ions.…”

“…The first project carried out on the Buyukmelen River basin is by the DSI (Efelerli and Oktas, 1997). The second study is a geological survey that studied water quality and water-rock interaction in the 470 km 2 area of the Buyukmelen River basin (Pehlivan and Yilmaz, 2005).…”

Groundwater contamination and its effect on health in Turkey

“…The existence of Mn and Zn in the Elmalı drinking water reservoir oḟ Istanbul and Fe in the River Büyükmelen water indicates natural inorganic contamination. Mn, Zn, and Fe contents in the water are of geological origin (Pehlivan and Yılmaz 2005). The average surface water quality aroundİstanbul is classified as slightly polluted in Darlık, Terkos, Büyükçekmece, and Alibeyköy and highly polluted in Elmalı reservoir.…”