壳聚糖复合净水剂处理再生造纸废水的研究

考察了pH值、壳聚糖用量、搅拌速率及静置时间等对COD去除率的影响,得出了最佳实验条件:pH值6 5～6 7,搅拌速率120r/min,静置时间12h,壳聚糖最佳用量为0 4g/L,在此条件下废水的COD去除率可达66%以上·壳聚糖处理效果明显优于无机混凝剂硫酸铝;将壳聚糖与硫酸铝进行配比制得复合净水剂处理再生造纸废水,可进一步提高COD的去除率,去除率可达到83%以上·该净水剂既可以有较高COD去除率,又可以避免二次污染,有较好的环保效果·

Wastewater Treatment by Composite Chitosan as Biosorbent for Repulped Papermaking Plants

The wastewater treatment for repulped papermaking plants using chitosan and its composite chitosan as biosorbents is studied. The effects of pH value, chitosan dosage, stirring speed and resting time on COD removal rate are investigated to obtain the optimal experimental conditions, i.e., pH value range of wastewater: 6.5-6.7, stirring speed: 120 rpm, resting time: 12 hr and chitosan dosage: 0.4 g/L. Under the conditions the COD removal rate of wastewater can be over 66%. The results show that the chitosan is obviously superior to the non-organic flocculant Al2(SO4)3 in biosorption process. Moreover, the chitosan can be used further by combining it with Al2(SO4)3 in a certain proportion to form a new composite purificant or biosorbent to wastewater treatment for repulped papermaking plants, by which the COD removal rate can be up to 83% even more. It will not only improve the COD removal rate but avoid secondary pollution, with better environment protection effect available.