氯化镧和硫酸铈对MBR活性污泥过滤性能的影响

膜污染一直以来是制约膜生物反应器广泛应用的主要因素,近年来人们用投加添加剂调控混合液的方法来减缓膜污染,并取得了一定的成效。本实验主要研究氯化镧和硫酸铈作为添加剂对膜污染的影响,通过膜阻力分布和污泥比阻的测定,分析在最佳投加量下两种稀土化合物对改善污泥混合液过滤性能、减缓膜污染的效果。结果表明:两种添加剂都可以降低膜的过滤总阻力及沉积层阻力以减缓膜污染;在最佳投加量下,沉积层阻力降低了40.93%(氯化镧)和49.16%(硫酸铈),污染阻力降低了96.20%(氯化镧)和96.94%(硫酸铈);污泥比阻降低了79.54%(氯化镧)和76.29%(硫酸铈);两者效果相似,但氯化镧可以改善污泥的压缩性能,且硫酸铈的最佳投加量较高,对反应器中的污泥活性产生抑制作用,不利于反应器的运行。

Effect of lanthanum chloride (LaCl3) and cerium sulfate (Ce(SO4)2) on filterability of MBR sludge

Membrane fouling is the major limitation to the wide-spread application of membrane bioreactor (MBR). Recently, some additives were used to alter the characteristic of the mixture, and found it could slow down the membrane fouling. This study was to investigate the influence of LaCl3 and Ce(SO4)2 on membrane fouling in MBR. Resistance distribution and specific cake resistance were measured to compare the filterability of LaCl3 and Ce(SO4)2 with blank. The results showed that the two additives could ameliorate the mixture filterability and retard the membrane fouling. At their optimum dosages, the specific cake resistances decreased 40.93% (LaCl3) and 49.16% (Ce(SO4)2), fouling resistances 96.20% (LaCl3) and 96.94% (Ce(SO4)2) and cake resistances decreased 79.54% (LaCl3) and 76.29% (Ce(SO4)2) as well. Although the effects of the two additives were similar, LaCl3 could improve the compression performance of sludge. Besides, the higher optimum dosage of Ce(SO4)2 would inhibit the sludge activity in MBR which was not good for the operation of the reactor.