Cranfield Water Science Institute, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK.
Water Res. 2011 Dec 1;45(19):6471-8. doi: 10.1016/j.watres.2011.09.039. Epub 2011 Sep 24.
A range of coagulant chemicals and doses, up to 2 mg/L, were trialled on a microfiltration-based indirect potable reuse (IPR) pilot plant to evaluate their impact on membrane reversible and irreversible fouling. Jar tests revealed these doses to have negligible impact on organic matter removal, whilst scoping pilot trials showed them to have a positive impact on fouling rates. Initial trials carried out over a 6-h period suggested that ferric sulphate was the most promising of the coagulants tested with regards to irreversible fouling. Extended five-day trials using ferric sulphate at 0.5 mg/L were conducted at fluxes of 40-50 l/(m(2)h) (LMH). Operation at 50 LMH without coagulant resulted in rapid fouling and a subsequent shortening of the chemical cleaning interval. The addition of the ferric coagulant resulted in a reduction in both reversible and irreversible fouling to those levels experienced at 40 LMH, enabling sustainable operation. The use of low levels of coagulant thus enables the pilot plant to operate at a 25% increased flux, equating to a 20% reduction in membrane area and overall savings of >0.1 p per m(3) for a seven year membrane life.
一系列的混凝剂化学品和剂量，高达 2 毫克/升，在基于微滤的间接饮用水再利用（IPR）中试工厂进行了试验，以评估它们对膜可逆和不可逆污染的影响。瓶试验表明，这些剂量对有机物去除几乎没有影响，而初步试验表明，这些剂量对污染速率有积极影响。在 6 小时的初步试验中，硫酸铁被认为是最有前途的混凝剂，在不可逆污染方面。在通量为 40-50 l/（m(2)h）（LMH）的情况下，使用硫酸铁进行了为期五天的扩展试验。在没有混凝剂的情况下以 50 LMH 运行会导致快速污染，并随后缩短化学清洗间隔。添加铁混凝剂可降低可逆和不可逆污染，使其达到 40 LMH 时的水平，从而实现可持续运行。因此，低水平的混凝剂可使中试工厂的通量增加 25%，相当于膜面积减少 20%，在膜寿命为七年的情况下，总节省超过 0.1 便士/立方米。
