The existence of Ca2+ and Mg2+ in the leachate during the mechanical vapor compression (MVC) treatment will lead to some problems such as scale formation and the difficulty of the subsequent processing.In this work,the adsorption characteristics of 732 cation exchange resin on Ca2+ and Mg2+ in the synthetic solutions using static adsorption method was studied.The results showed that the removal rates of Ca2+ and Mg2+ with mass concentrations of 200 mg/L were 88.8 ％ and 68.3 ％,respectively,under the condition of 8 g/L 732 cation exchange resin,30 ℃,pH=7.0 and 30 min adsorption time.The adsorption process followed the Langmuir isothermal equation,with correlation coefficients (R2) of 0.992 5 (Ca2+) and 0.952 3 (Mg2+),respectively.Then the real leachate was used for the adsorption and it found that the removal rates of Ca2+ and Mg2+ were 69.9％ and 70.9％,respectively,using a similar condition with the synthetic solution.The leachate effluent obtained after 732 cation exchange resin treatment was suitable for the subsequent evaporation using MVC to inhibit scaling and to decrease the treatment cost of concentration.%机械蒸汽压缩(MVC)蒸发处理渗滤液过程中,Ca2+和Mg2+的大量存在会导致结垢及浓缩液后续处理困难等问题.通过静态吸附实验,探索了732型阳离子交换树脂对渗滤液中Ca2+、Mg2+的吸附特性.实验结果表明,在pH=7、温度为30℃、732型阳离子交换树脂投加量为8 g/L、吸附时间为30 min的条件下,对于Ca2+和Mg2+(摩尔比为3∶5)的质量浓度为2 000mg/L的混合溶液,两者的去除率分别为88.8％、68.3％.732型阳离子交换树脂对Ca2+和Mg2+的吸附行为均符合Langmuir吸附等温方程,相关性系数(R 2)分别为0.992 5、0.952 3.利用732型阳离子交换树脂处理实际渗滤液,吸附条件与混合溶液相同,结果表明,对实际渗滤液中Ca2+和Mg2+的去除率分别达到为69.9％、70.9％.经过732型阳离子交换树脂吸附预处理后的渗滤液再经MVC蒸发处理,可有效减少MVC蒸发过程中的结垢,并降低浓缩液后续处理成本.
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