Effectiveness of seawater reverse osmosis (SWRO) pretreatment systems in removing transparent exopolymer particles (TEP) substances

الموضوعات

علوم بحتة وطبيعية

الملخص

Transparent exopolymer particles (TEP) have been reported as one of the main factors of membrane fouling in seawater reverse osmosis (SWRO) process. Research has been focused on algal TEP so far, overlooking bacterial TEP. This thesis investigated the effects of coagulation on removal of bacterial TEP/TEP precursors in seawater and subsequent reduction on TEP fouling in ultrafiltration (UF), as a pretreatment of SWRO. Furthermore, the performance of pretreatment (coagulation + UF) has been investigated on a bench-scale SWRO system. TEP/TEP precursors were harvested from a strain of marine bacteria, Pseudoalteromonas atlantica, isolated from the Red Sea. Isolated bacterial organic matter (BOM), containing 1.5 mg xanthan gum eq./L TEP/TEP precursors, were dosed in Red Sea water to mimic a high TEP concentration event. Bacterial TEP/TEP precursors added to seawater were coagulated with ferric chloride and aluminum sulfate at different dosages and pH. Results showed that ferric chloride had a better removal efficiency on TEP/TEP precursors.Afterwards, the non-coagulated/coagulated seawater were tested on a UF system at a constant flux of 130 L/m2h, using two types of commercially available membranes, with pore sizes of 50 kDa and 100 kDa, respectively. The fouling potential of coagulated water was determined by the Modified Fouling Index (MFI-UF). Transmembrane pressure (TMP) was also continuously monitored to investigate the fouling development on UF membranes. TEP concentrations in samples were determined by the alcian blue staining assay. Liquid chromatography-organic carbon detection (LC-OCD) was used to determine the removal of TEP precursors with particular emphasis on biopolymers.Finally, SWRO tests showed that TEP/TEP precursors had a high fouling potential as indicated by MFI-UF, corresponding to the TMP measurements. Coagulation could substantially reduce TEP/TEP precursors fouling in UF when its dosage was equal or higher than 0.2 mg Fe/L. The flux decline experiments showed that coagulation + UF pretreated water had a smaller fouling potential than MF pretreated water. This thesis also provides useful and practical information on controlling bacterial TEP/TEP precursors fouling in UF and RO systems.

روابط وملفات

التعريف والنوع

رقم الوثيقة

0d29d8d6-95bb-4a98-a17d-7d4bf6b0c64a

رقم العقد

0

نوع الوسائط

Crawler

نوع المحتوى

الرسائل العلمية

صيغة المصدر

رسائل ماجيستير

نوع الملف

pdf text

أسماء الملفات

1700142_1.pdf

بيانات النشر

ألقاب المؤلفين

[{"name_ar":" Shang Tse Lee","title_ar":"اعداد","title_en":"Preparation"},{"name_ar":"TorOve Leiknes","title_ar":"اشراف","title_en":"Supervision"}]

اللغة

English

المصدر والدورية

اسم المصدر

Effectiveness of seawater reverse osmosis (SWRO) pretreatment systems in removing transparent exopolymer particles (TEP) substances

المحتوى والصفحات

عدد الصفحات

0

كلمات الباحثين

Biofouling , Coagulation , Desalination , Reverse Osmosis , Transparent Exopolymer Particles (TEP) , Ultrafiltration

إشراف وإعداد

الإشراف

TorOve Leiknes

الإعداد

Shang Tse Lee

الاقتباسات الببليوغرافية