Kızılırmak Deltası kıyı şeridinde su ve midye örneklerinde PAH kirliliğinin araştırılması

Abstract

Polisiklik Aromatik Hidrokarbon (PAH) bileşikleri su ortamına; fosil yakıtların dökülmesi ve sızıntısı, evsel-endüstriyel atıkların ve kanalizasyon sularının deşarjı, atmosferik partiküllerin çökelmesi, araç egzozlarının yoğunlaşması, asfalt yol yüzeyinin aşınımı ve süzülmesi gibi nedenlerle PAH bileşiklerini içeren yüzey sularının akışıyla su ortamına girebilmektedir. Böylelikle PAH bileşikleri kirlenmiş nehir sularında yüksek konsantrasyonlarda bulunabilmektedir. Bu sebeple kirlenmiş nehirlerin mansaplandığı deniz ortamlarında da PAH bileşiklerine rastlamak mümkündür. PAH’lar sudaki canlıların bünyelerinde kolayca birikirler ve canlı bünyesinde su ortamından daha yüksek seviyelere ulaşırlar. PAH’lar genellikle deniz ortamında su kütlesinde düşük ve midyelerde yüksek miktarda bulunurlar. Bu çalışmada Samsun İli’nde Kızılırmak Nehri’nin Karadeniz ile birleştiği noktadan mevsimsel olarak alınan su örneklerinde ve aynı tarihlerde alınan Mytilus Galloprovincialis türü midye örneklerinde PAH türevlerinden olan krisen, benz(a)piren, naftalen ve antrasen GC-FID ile tayin edilmiştir. Ayrıca midye örneklerinde eksktrakte olabilir organik madde (EOM) tayini de yapılmıştır. Midye örneklerinde su örneklerine nazaran PAH konsantrasyonunun çok daha yüksek olduğu saptanmıştır. Su ve midye örneklerinde saptanan en yüksek toplam PAH konsantrasyonu Mart 2002 tarihinde alınan su örneği için 14.175 ppb ve midye örneği için 431.863 ppb’dir. Çalışma süresi boyunca ortalama konsantrasyonu en yüksek PAH bileşiği su örneklerinde 2.670 ppb konsantrasyonuyla krisendir ve aynı şekilde midye örneklerinde de 167.905 ppb konsantrasyonuyla krisendir.

Polycyclic Aromatic Hydrocarbons (PAH) may reach the aquatic environment by a variety of routes. Major routes of entry of PAH into marine and fresh waters include biosynthesis, spillage and seepage of fosil fuels, discharge of domestic and industrial wastes, fallout or rainout from air, and runof from land. Spillage and seepage of petroleum into marine and fresh waters is an important source of PAH. Industrial and domestic sewage often contains high concentraions of particulate and soluble PAH. Stormsewage (runoff from roadways) contains PAH from wear and leaching of asphalt road surfaces, wear of vehicle tires that contain carbon black, condensations from vehicular exhaust, and from the all too common practice of oiling roadsidesand unpaved roadways with used crankcase oil, which is high in PAH. Relative concentrations of PAH aquatic ecosystems are generally highest in the sediments, intermediate in aquatic biota, and lowest in the water column. Most of the environmental PAH burden remains relatively near the point sources of PAH, and concentrations decrease approximately with distance from the source. Thus most of the PAH entering the aquatic environment are localized in rivers, estuaries, and coastal marine waters. In this study, it was aimed to investigate the changes in water quality of Kızılırmak River between April 2001-April 2002 and to determinate the pollution accumulation in the mussel samples in the coastal area, in the Kızılırmak Delta where located in the north of the Samsun-Sinop highway with in the borders Bafra, Alaçam and Ondozkuzmayıs townships of Samsun. During a year, water samples and mussel samples were collected from the points where Kızılırmak River joins the Black Sea. The water quality of Kızılırmak River was evaluated based on measurements conducted within the framework of this study. Another aim of this research was to investigate the sea pollution of the coastal area of Kızılırmak Delta by using a different method. Mytilus galloprovincialis type mussels were choosen as a biomonitoring organism to achieve this aim. During the study period, March 2002 was determined as the month when the PAH pollution accumulation in the mussel samples was maximum (431,863 ppb). Polycylic Aromatic Hydrocarbons (PAH) compounds were analyzed in the water samples and mussel samples (Mytilus galloprovincialis) from were collected at the same time from the Kızılırmak River joins the Black Sea, Besides, Extractable Organic Matter (EOM) was measured in the mussels samples. To determine the relation between EOM contents and concentrations of PAH compounds that were determined in the mussel samples, linear regression and correlation applications were done between EOM and concentrations of PAH compounds. For analysis of PAH compounds, mussel samples and water samples were collected four times a year at the same time as seasonal. Chrysene, benzo(a)pyrene, naphthalene and anthracene were determined as PAH compounds in the mussels and water samples. In the sample extracts that were obtained from the mussels and the water samples, PAH compounds were measured by using Gas Chromatography with flame ionization detector (FID). In addition, the recovery efficiencies of PAH compounds of extractions were determined by using internal standarts and enjecting to the gas chromatography and spesific retention times of PAH compounds were determined by enjecting PAH standarts to the gas chromatography. As a result, it was determined that concentrations of PAH compounds in the mussel samples were higher than concentrations of PAH compounds in the water samples. Due to high molecular weight, low water solubility, sorption tendency to particle matters, accumulation tendency to sediment and to aquatic organisms of PAH compounds, low concentrations of PAH compounds were determined in the water samples. The highest total PAH concentration was 14.175 ppb in water samples and 43.863 ppb in mussel samples in March 2002. The highest mean concentration of PAH compounds was 2.670 ppb (chrysene) in water samples. The highest mean concentration of PAH compounds was 167.905 ppb (chrysene) in mussels samples. It was determined that the lowest of extractable organic matter (EOM) in mussel samples was 18.642 in June 2001, and the lowest of total PAH concentration in mussel samples was 217.673 ppb in June 2001.