摘要
聚合有机物强化超滤技术因具有操作压力低、膜通量大且截留效果好的优点,而受到了广泛的关注。文章研究了天然有机物海藻酸钠强化超滤去除模拟含铜废水的特性及影响因素,试验结果表明,当海藻酸钠投加量为100 mg/L,pH=6.0,温度为25℃,Cu2+初始浓度为10 mg/L时,MWCO(截留分子量)为4 kDa,6 kDa,10 kDa,30 kDa,50 kDa,70 kDa的膜均可实现对其的高效截留,截留效率可达86%～95%。随着膜的截留分子量增大,超滤膜对Cu2+的截留效果逐渐降低。Cu2+的截留效率随着pH的降低而减小,当pH=3时,MWCO 30 kDa的超滤膜对Cu2+的截留效率仅为42%。海藻酸钠强化超滤时膜阻力主要由浓差极化阻力和堵孔阻力组成,两者构成了总阻力的80%以上。当pH值调节到13时,可使得浓缩液中与海藻酸钠结合的90%以上的Cu2+沉淀析出,实现回收。
Much attention has been paid on the polymer enhanced ultrafiltration technology due to its advantages of low operation pressure,high flux and high heavy metal rejections.Effect factors and characteristics of alginate-enhanced ultrafiltration to treat copper wastewater were investigated.Experimental results showed that UF membranes with MWCO 4 kDa,6 kDa,10 kDa,30 kDa,50 kDa and 70 kDa could remove the copper ion with efficiency of 86%～95% under the conditions of initial Cu2＋ concentration 10 mg/L,alginate concentration 100 mg/L,pH 6.0 and treatment at 25℃.However,Cu2＋ rejection rate decreased as MWCO of UF membranes increased and pH was dropped.UF membrane with MWCO 30 kDa could only reject 42% of total Cu2＋ at pH 3.80% of total membrane resistances came from the pore-blocked and concentration polarization during the filtration process.More than 90% of total copper in the concentrated solution could be recovered by increasing pH value to 13 in order to form Cu（OH）2 sediment.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2011年第4期77-80,103,共5页
Environmental Science & Technology
基金
国家自然科学基金(50608070)
中山大学后备重点基金项目
