Zielińska Magdalena, Galik Maciej
Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Słoneczna Str. 45G, 10-709 Olsztyn, Poland.
Water Air Soil Pollut. 2017;228(5):173. doi: 10.1007/s11270-017-3365-x. Epub 2017 Apr 10.
A membrane filtration system was used to remove organic compounds, suspended solids, colour and turbidity from anaerobically treated dairy wastewater. Direct microfiltration (MF), ultrafiltration (UF), MF-UF and a combination of UF with coagulation using two conventional coagulants were investigated. The installation with ceramic membranes was operated at a pressure of 0.15 MPa (MF) and 0.3 MPa (UF). COD removal was 89 ± 2% in MF, 95 ± 1% in UF and 99% in MF-UF. Apart from size exclusion, removal was also the result of adsorption of organics on the membrane; 3-18% of COD removal was attributed to adsorption. In all these membrane systems, colour removal was 96-98%. Coagulation removed 63-72% of COD at all coagulant doses. In combination with UF, 96-97% of COD was removed. The use of coagulants was ineffective for colour removal; further treatment by UF resulted in above 98% removal. Because of complete rejection of suspended solids, turbidity removal exceeded 99% under all conditions. The use of increased coagulant doses did not have an effect on total efficiency of pollutant removal and on the permeate flux. Coagulation pre-treatment enhanced the performance of filtration only by lengthening the filtration cycle by about 12% as compared to direct UF. Not only was pollutant removal highest in MF-UF, but also the average permeate flux was about 80% higher in this two-stage system than in direct UF. This study shows that the most effective strategy to mitigate membrane fouling is the use of MF as a pre-treatment preceding UF.
采用膜过滤系统去除厌氧处理后的乳制品废水中的有机化合物、悬浮固体、颜色和浊度。研究了直接微滤（MF）、超滤（UF）、MF-UF以及使用两种传统混凝剂将UF与混凝相结合的方法。陶瓷膜装置在0.15MPa（MF）和0.3MPa（UF）的压力下运行。MF的化学需氧量（COD）去除率为89±2%，UF为95±1%，MF-UF为99%。除了尺寸排阻外，去除还归因于有机物在膜上的吸附；3-18%的COD去除归因于吸附。在所有这些膜系统中，颜色去除率为96-98%。在所有混凝剂剂量下，混凝去除了63-72%的COD。与UF结合使用时，COD去除率为96-97%。使用混凝剂对颜色去除无效；通过UF进一步处理后去除率超过98%。由于完全截留悬浮固体，在所有条件下浊度去除率超过99%。增加混凝剂剂量对污染物去除的总效率和渗透通量没有影响。与直接UF相比，混凝预处理仅通过将过滤周期延长约12%来提高过滤性能。不仅MF-UF中的污染物去除率最高，而且在这个两级系统中平均渗透通量比直接UF高约80%。这项研究表明，减轻膜污染最有效的策略是使用MF作为UF之前的预处理。
