PSU-g-SBMA hollow fiber membrane for treatment of oily wastewater.

Chong Shen,Qin Meng,Qian Zhang

doi:10.2166/wst.2021.363

Abstract

Ultrafiltration membranes can intercept oil particles smaller than 10 μm, but the membranes are easily contaminated by oil due to their hydrophobicity. To treat various oily wastewaters, we prepared a hydrophilic hollow fiber membrane (HFM) with anti-fouling property by grafting sulfobetaine methacrylate (SBMA) onto polysulfone (PSU). For six simulated wastewaters containing emulsified oil at 1,000 mg/L, the PSU-g-SBMA HFM was able to remove 98.5-99.7% of oil, higher than that of PSU HFM at 91.1-98.9%. The oil concentration in filtrate was less than 15 mg/L, which could meet the discharge standard of wastewater. The water flux of PSU-g-SBMA HFM can be completely recovered after being washed by rhamnolipid and alkali solution, while the same cleaning process could not recover the PSU HFM. As found, the contact angles of oil droplets on the PSU-g-SBMA membrane were larger than those on PSU membrane, which indicated the improved hydrophilicity by PSU-g-SBMA. For 48 h of filtration to soybean and diesel oil/water emulsion, the effect of PSU-g-SBMA HFM was stable and the flux could be completely recovered by cleaning. Therefore, we provided a new method for oily wastewater treatment, which can efficiently and energy-saving remove various oil substances in wastewater.

Highlights

Wastewater comes from a wide range of sources, such as petroleum exploitation, petrochemical industry, marine transportation, wool and leather manufacturing, dairy processing, pharmaceutical production, and kitchen wastewater
Chemicals Polysulfone (PSU) powder with molecular weight of 66,000 was purchased from Shanghai Shuguang Chemical Factory; sulfobetaine methacrylate (SBMA) was purchased from Sigma-Aldrich company; Cuprous chloride (CuCl) and 2,2 ‘- bipyridine were purchased from Aladdin reagent (Shanghai) Co., Ltd; Methanol, dimethyl sulfoxide (DMSO), N-methyl pyrrolidone (NMP), tetrahydrofuran (THF) and acetone were purchased from Shanghai Sinopharm Chemical Reagent Co., Ltd; Chloromethyl polysulfone (CMPSU) was made in laboratory
Preparation of PSU-g-SBMA hollow fiber membrane As shown in Figure 1, CMPSU prepared in the laboratory was dissolved in 50 ml DMSO to a 36 g/L solution, and SBMA was further dissolved in DMSO at the ratio of 4:1

Summary

Introduction

Wastewater comes from a wide range of sources, such as petroleum exploitation, petrochemical industry, marine transportation, wool and leather manufacturing, dairy processing, pharmaceutical production, and kitchen wastewater. Membrane filtration can remove particles smaller than 10 μm, so that membrane technology has been widely used to treat emulsified oily wastewater in recent years (Pulido 2016; Tanudjaja et al 2019; Bolto et al 2020). A typical ultrafiltration membrane is for treatment of water containing 10–10,000 mg/L of oil, and is able to remove more than 90% of oil (Tanudjaja et al 2019; Bolto et al 2020). The flux of contaminated membrane could not be completely recovered by

Methods

Results

Conclusion