工业水处理 ›› 2022, Vol. 42 ›› Issue (2): 88-94. doi: 10.19965/j.cnki.iwt.2021-0579

• 试验研究 • 上一篇    下一篇

DWTR-PAC强化混凝去除水中Cr(Ⅵ)的研究及参数优化

陈子涵(), 张笑语, 尹兴新, 黄培锦, 梁志杰()   

  1. 重庆大学三峡库区生态环境教育部重点实验室,重庆 400000
  • 收稿日期:2021-12-22 出版日期:2022-02-20 发布日期:2022-03-15
  • 作者简介:

    陈子涵(1999— ),本科生。E⁃mail:

    梁志杰,博士,副教授,博士生导师。E⁃mail:

  • 基金资助:
    国家自然科学基金项目(51808066); 重庆市大学生创新训练项目(S202010611364)

Study and parameters optimization of Cr(Ⅵ)removal from water by DWTR-PAC composite enhanced coagulation

Zihan CHEN(), Xiaoyu ZHANG, Xingxin YIN, Peijin HUANG, Zhijie LIANG()   

  1. Key Laboratory of the Three Gorges Reservoir Region’s Eco-Environment,Ministry of Education,Chongqing University,Chongqing 400000,China
  • Received:2021-12-22 Online:2022-02-20 Published:2022-03-15

摘要:

给水污泥(DWTR)是自来水厂产生的废弃物,通常以填埋形式处置,但其中大量具有无机阴离子吸附潜能的氢氧化铝未得到充分利用。本研究尝试建立基于给水污泥吸附耦合二次絮凝沉淀的Cr(Ⅵ)控制技术,并系统优化工艺条件,以增强工业废水处理中对Cr(Ⅵ)的去除效果,同步实现给水污泥的资源化利用。结果表明:DWTR对Cr(Ⅵ)的吸附符合二级动力学方程,化学吸附作用占主导地位,吸附容量为5.910 mg/g。利用响应面法(Box-Behnken模型)考察PAC和DWTR总投加量、PAC与DWTR的投加比例和工艺体系pH对DWTR-PAC复合强化混凝去除水中Cr(Ⅵ)的影响。验证了该模型下的最优方案,并设置多组对照实验加以验证,在与纯PAC体系、无吸附DWTR与PAC混合体系、纯DWTR体系等的对比中发现,当PAC的投加量为12.94 g/L、DWTR的投加量为21.05 g/L、溶液pH为5.95时,DWTR-PAC体系展现出明显优势,模型预测其对Cr(Ⅵ)的去除率为99.8%(实测为99.85%)。

关键词: 给水污泥, 聚合氯化铝, 除铬, 混凝, 响应面

Abstract:

Drinking water treatment residual(DWTR) is a waste generated from water plants and is usually disposed of in landfill. However,a large amount of aluminum hydroxide with the potential for adsorption of inorganic anions,has not been fully utilized. It was attempted to establish a Cr(Ⅵ) control technology based on the adsorption of DWTR coupled with secondary flocculation and sedimentation in present work. The process conditions were systematically optimized to enhance the removal of Cr(Ⅵ) in industrial wastewater and simultaneously realize the utilization of DWTR. The results showed that the adsorption of Cr(Ⅵ) by DWTR conformed to the second-order kinetic equation,in which the chemical adsorption was dominant,and the adsorption capacity was 5.910 mg/g. Furthermore,the response surface method(Box-Behnken model) was used to investigate the effect of the total dosage of PAC and DWTR,the dosage ratio of PAC to DWTR,and the pH of the process system on the removal of Cr(Ⅵ) from water by DWTR-PAC composite enhanced coagulation. The optimal scheme under this model was verified and multiple sets of control experiments were set up to verify it. Compared with pure PAC system,non-adsorption DWTR and PAC mixed system,and pure DWTR system,with the condition of dosage of PAC 12.94 g/L,the dosage of DWTR 21.05 g/L,and the pH of the solution 5.95,the system showed obvious advantages. The model predicted the removal rate of Cr(Ⅵ) was 99.8%(the measured value was 99.85%).

Key words: drinking water treatment residual, polyaluminium chlorine, Cr(Ⅵ)removal, coagulation, response surface

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