膜蒸馏处理糖精钠生产废水

采用直接接触式膜蒸馏(DCMD)工艺处理糖精钠生产废水。分析了经过活性炭吸附预处理前后,膜蒸馏连续循环运行的效果。实验结果表明,未经预处理的废水在膜蒸馏过程中,废水中所含有机物不仅导致膜材料的润湿,引起产水电导率升高及膜孔润湿,促进盐晶体在膜表面附着,使产水通量下降。经吸附预处理后,膜蒸馏过程中产水通量介于10.40～11.24 kg/(m2.h)。吸附预处理能有效减缓产水通量的衰减,提高产水水质。废水经过活性炭预处理后进行膜蒸馏浓缩处理,当浓缩倍数达到5倍时,通量保持在10.55 kg/(m2.h)左右;产水水质稳定,截留率在99.5%以上。研究结果表明,吸附-膜蒸馏工艺可以应用于糖精钠生产废水的回用处理,有明显的应用前景。

Treatment of saccharin wastewater by membrane distillation

Direct contact membrane distillation(DCMD) was used for the treatment of saccharin wastewater.Membrane distillation experiments with wastewater before and after adsorption as feed were carried out,respectively.The results showed that before adsorption organic matter in the water increased the probability of membrane wetting and the permeate conductivity;it also accelerated salt scales and decreased permeate flux.The membrane flux was in the range of 10.40 to 11.24 kg/(m2·h) after the pretreatment.It was suggested that the pretreatment decreased membrane fouling,maintained a stability of permeate flux and greatly improved permeate water quality.The concentration experimental results indicated that the module efficiency kept stable before concentration factor reached 5.0 with the wastewater after adsorption as feed,while the permeate flux was about 10.55 kg/(m2·h).The permeate water quality kept stable and the rejection rate was greater than 99.5% in all MD experiments with the wastewater after pretreatment as feed.Therefore,the integrated process of adsorption and MD may be of great potential to be utilized for treating saccharin wastewater.