【作者】 厉威；

【导师】 陈雪明；

【作者基本信息】 浙江大学 ， 环境工程， 2010， 硕士

【摘要】 六价铬,Cr(VI),毒性大,可以致癌、致畸、致突变。然而,Cr(VI)较贵重,具有很高的回收价值。因此,研发同步去除和回收Cr(VI)的资源化处理技术具有极大环境和经济意义。目前处理含Cr(VI)废水的方法有多种,这些方法各有优势,但均难以在高效去除Cr(VI)的同时,对Cr(VI)进行回收。本研究旨在对传统电渗析(ED)进行改进,通过多次折流并增加段数,实现从废水中高效同步去除与回收Cr(VI)。首先考察了所研发的多段多折流ED装置间歇净化含Cr(VI)废水的基本情况。结果表明,新型ED装置能够高效处理含Cr(VI)废水。Cr(VI)浓度可由原来的50-150mg╱L降至0.5mg╱L以下,典型条件下的电流效率高达30.9%,能耗为2.59kWh/molCr(VI)。在间歇处理研究基础上,系统考察了新型ED装置连续资源化处理含Cr(VI)废水的性能。结果表明,该装置可实现从废水中高效同步去除与回收Cr(VI)。处理后,淡室出水Cr(VI)浓度可由原来的50-150 mg╱L降至0.5mg╱L以下;与此同时,浓水出水Cr(VI)浓度可达10g╱L以上;电流效率与能耗分别为4.84-11.45%与2.24-6.97kWh/mol Cr(VI)。在连续运行状况下,还考察了电流、流量和进水Cr(VI)浓度对处理效果的影响,提出了一种优化系统运行的简易方法,即荷质比(CMR)控制法。结果表明,CMR与出水Cr(VI)浓度密切相关,且ED过程存在一个CMR最优值。根据CMR最优值,可以针对废水水质和流量的波动调整电流,确保ED高效率低能耗地连续稳定运行。更多还原

【Abstract】 Hexavalent chromium,Cr(Ⅵ),is toxic,and can act as carcinogens,mutagens,and teratogens.However,Cr(Ⅵ) is expensive.Thus,it is significant to develop a technique of simultaneous removal and recovery of Cr(Ⅵ) for environmental pollution abatement and economic purpose.Currently,there are many methods available for the treatment of the wastewater containing ion Cr(Ⅵ),which have their own advantages.However,none of them can achieve simultaneous removal and recovery of Cr(Ⅵ) from wastewater.The major objective of this work is to remove and recover Cr(Ⅵ) efficiently from wastewater using an ED unit with multi baffles and multi stages.In order to investigate the basic performance for wastewater purification,the ED unit developed was operated in batch first.It was revealed that the ED unit with multi baffles and multi stages could treat the wastewater containing Cr(Ⅵ) efficiently. Concentration of Cr(Ⅵ) was reduced from the initial 50-150 mg/L to lower than 0.5mg/L under typical conditions.The current efficiency reached 30.9%,and the power consumption was only 2.59kWh/mol Cr(Ⅵ).With these results above,the ED unit was operated in a continuous mode.The results showed that Cr(Ⅵ) could be removed and recovered efficiently.After treatment,the concentration of Cr(Ⅵ) in the dilute effluent decreased from the initial 50-150 mg/L to lower than 0.5mg/L, while the concentration of Cr(Ⅵ) in the concentrated effluent was higher than 10g/L, with current efficiencies of 4.84-11.45%and power consumptions of 2.24-6.97kWh/mol Cr(Ⅵ) being obtained.The effects of current,flowrate and initial Cr(Ⅵ) concentration on the purification efficiency were also investigated,and a simple way to optimize the ED operation was proposed,which used a new concept of charge-mass ratio(CMR).The results showed that the Cr(Ⅵ) concentration in the effluent was highly dependent on CMR,and there was a optimal value for CMR under which the ED unit could be operated continuously,efficiently,economically and steadily by adjusting the current on the basis of the quality and the flowrate of the wastewater treated.更多还原