Nguyen Nguyen Cong, Nguyen Hau Thi, Chen Shiao-Shing, Nguyen Nhat Thien, Li Chi-Wang
Institute of Environmental Engineering and Management, National Taipei University of Technology, No.1, Sec. 3, Chung -Hsiao E. Rd, Taipei 106, Taiwan, ROC E-mail:
Department of Water Resources and Environmental Engineering, TamKang University, 151 Yingzhuan Road, Tamsui District, New Taipei City 25137, Taiwan, ROC.
Water Sci Technol. 2015;72(8):1301-7. doi: 10.2166/wst.2015.341.
Forward osmosis (FO) is an emerging process for dewatering solid-liquid stream which has the potential to be innovative and sustainable. However, the applications have still been hindered by low water flux and membrane fouling when activated sludge is used as the feed solution due to bound water from microbial cells. Hence, a novel strategy was designed to increase sludge thickening and reduce membrane fouling in the FO process under ultrasonic condition. The results from the ultrasound/FO hybrid system showed that the sludge concentration reached up to 20,400 and 28,400 mg/L from initial sludge concentrations of 3000 and 8000 mg/L with frequency of 40 kHz after 22 hours, while the system without ultrasound had to spend 26 hours to achieve the same sludge concentration. This identifies that the presence of ultrasound strongly affected sludge structure as well as sludge thickening of the FO process. Furthermore, the ultrasound/FO hybrid system could achieve NH4+-N removal efficiency of 96%, PO4(3-)-P of 98% and dissolved organic carbon (DOC) of 99%. The overall performance demonstrates that the proposed ultrasound/FO system using seawater as a draw solution is promising for sludge thickening application.
正向渗透（FO）是一种新兴的用于固液流脱水的工艺，具有创新和可持续的潜力。然而，当以活性污泥作为进料溶液时，由于微生物细胞中的结合水，其应用仍然受到低水通量和膜污染的阻碍。因此，设计了一种新策略，以在超声条件下提高FO工艺中的污泥浓缩并减少膜污染。超声/FO混合系统的结果表明，在40kHz频率下，初始污泥浓度为3000mg/L和8000mg/L时，22小时后污泥浓度分别达到20400mg/L和28400mg/L，而没有超声的系统则需要26小时才能达到相同的污泥浓度。这表明超声的存在强烈影响了FO工艺的污泥结构以及污泥浓缩。此外，超声/FO混合系统可以实现96%的NH4+-N去除效率、98%的PO4(3-)-P去除效率和99%的溶解有机碳（DOC）去除效率。总体性能表明，所提出的以海水作为汲取溶液的超声/FO系统在污泥浓缩应用方面具有前景。
