Sulphate removal by nanofiltration from water

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Çevre Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2010

Öğrenci: ASLI KARABACAK

Danışman: ÜLKÜ YETİŞ

Özet:

ABSTRACT SULPHATE REMOVAL BY NANOFILTRATION FROM WATER Karabacak, Aslı M.Sc., Department of Environmental Engineering Supervisor: Prof. Dr. Ülkü Yetiş Co-advisor: Prof. Dr. Mehmet Kitiş December 2010, 152 pages Excess sulphate in drinking water poses a problem due to adverse effects on human health and also due to aesthetic reasons. This study examines the nanofiltration (NF) of sulphate in surface water using a laboratory cross-flow device in total recycle mode. In the study, three NF membranes, namely DK-NF, DL-NF and NF-270, are used. The influence of the main operating conditions (transmembrane pressure, tangential velocity and membrane type) on the steady-state permeates fluxes and the retention of sulphate are evaluated. Kızılırmak River water is used as the raw water sample. During the experimental studies, the performance of NF is assessed in terms of the parameters of UVA254, sulphate, TOC and conductivity of the feed and permeates waters. Results indicated that NF could reduce sulphate levels in the surface water to a level below the guideline values, with a removal efficiency of around 98% with all three membranes. DK-NF and NF-270 membranes showed fouling when the surface water was fed directly to the system without any pre-treatment. MF was found to be an effective pretreatment option for the prevention of the membrane fouling, but no further removal of sulphate was achieved. Parametric study was also conducted. No change in flux values and in the removal of sulphate was observed when the crossflow velocity was lowered. The flux values were decreased as the transmembrane pressure was lowered; however there were not any decrease in the sulphate removal efficiency.