Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Çevre Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2014
Tezin Dili: İngilizce
Öğrenci: Gökçe Somun
Danışman: BARIŞ KAYMAK
Özet:In the last decade, traces of pharmaceuticals and personal care products (PPCPs), mostly at levels in the ng/L to low μg/L range, have been reported in the water cycle, including surface waters, wastewater, groundwater, and drinking water and this has been a major concern in recent years. Simultaneously, formation of NNitrosodimethylamine (NDMA) as a disinfection by-product (DBP) during chloramine disinfection has become another important concern for drinking water quality because of its potent carcinogenicity. This study investigated NDMA formation potential of eight amine based PPCPs namely, ranitidine, doxylamine, diltiazem, sumatriptan, caffeine, diclofenac, atrazine and sulfamethoxazole during disinfection with 2-2.5 mg/L monochloramine and mutagenicity of PPCP and monochloramine mixture after 24 hours of reaction time. Water samples spiked with these PPCPs were subjected to disinfection process individually with monochloramine and NDMA formation was observed after 24 hours. NDMA concentrations were measured by gas chromatography/mass spectrophotometry (GC/MS). Four of the selected PPCPs, namely ranitidine, doxylamine, diltiazem and sumatriptan formed NDMA after reaction with monochloramine. The molar conversion rate for ranitidine, doxylamine, diltiazem and sumatriptan were average 123.3 %, 0.4 %, 0.6 % and 0.5 %, respectively. In the other four PPCPs, namely caffeine, diclofenac, atrazine and sulfamethoxazole, NDMA formation was observed but they were lower than the calibration range of GC/MS readings. The magnitude of NDMA formation potential from reaction between amine groups and monochloramine were dependent on molecular properties of PPCPs. In mutagenicity tests S.typhimurium TA100 strain showed higher mutation than S.typhimurium TA98 strain, in other words, TA100 strain seemed to be more sensitive to mutagenic effects of chemicals than that of TA98 strain. Mutations observed in doxylamine, samples were thought to be due to PPCPs. No conclusive NDMA mutagenicity was observed in samples tested without metabolic activation.