School of Chemical Engineering, Universiti Sains Malaysia Seri Ampangan, Penang, Malaysia.
Water Sci Technol. 2013;67(4):831-7. doi: 10.2166/wst.2012.625.
Aquaculture activities in developing countries have raised deep concern about nutrient pollution, especially excess phosphorus in wastewater, which leads to eutrophication. NF, NF90, NF450 and XLE membranes were studied to forecast the potential of nanofiltration and low pressure reverse osmosis in the removal of phosphorus from aquaculture wastewater. Cross-sectional morphology, water contact angle, water permeability and zeta potential of these membranes were first examined. Membrane with higher porosity and greater hydrophilicity showed better permeability. Membrane samples also commonly exhibited high zeta potential value in the polyphosphate-rich solution. All the selected membranes removed more than 90% of polyphosphate from the concentrated feed (75 mg/L) at 12 bar. The separation performance of XLE membrane was well maintained at 94.6% even at low pressure. At low feed concentration, more than 70.0% of phosphorus rejection was achieved using XLE membrane. The formation of intermolecular bonds between polyphosphate and the acquired membranes probably had improved the removal of polyphosphate at high feed concentration. XLE membrane was further tested and its rejection of polyphosphate reduced with the decline of pH and the addition of ammonium nitrate.
发展中国家的水产养殖活动引起了人们对营养物污染的深切关注，特别是废水中过量的磷会导致富营养化。研究了 NF、NF90、NF450 和 XLE 膜，以预测纳滤和低压反渗透在去除水产养殖废水中磷的潜力。首先检查了这些膜的横截面形态、水接触角、水渗透性和 ζ 电位。具有更高孔隙率和更大亲水性的膜表现出更好的渗透性。在富含多磷酸盐的溶液中，膜样品通常也表现出高 ζ 电位值。所有选定的膜在 12 巴的压力下，均能从浓缩饲料（75mg/L）中去除超过 90%的多磷酸盐。即使在低压下，XLE 膜的分离性能也能很好地保持在 94.6%。在低进料浓度下，XLE 膜的磷去除率超过 70.0%。多磷酸盐与获得的膜之间形成分子间键，可能提高了高进料浓度下多磷酸盐的去除率。进一步测试了 XLE 膜，发现其对多磷酸盐的截留率随着 pH 值的下降和硝酸铵的添加而降低。
