探讨了阳离子聚丙烯酰胺( CPAM ) 离子度、分子量及加入量对疏浚淤泥中镉( Cd) 吸附与解吸行为的影响及机 理。结果表明: 当淤泥初始Cd 浓度为0. 5 Lg / L 时, 加入CPAM 静置沉降后, 上清液中Cd 浓度基本小于0. 1 Lg / L, 与未加CPAM 自然沉降后上清液中的Cd 浓度基本一致; 而在真空抽滤条件下, 滤液中Cd 浓度最高可达到0. 35 Lg / L, 约64%的Cd 脱离淤泥颗粒进入到滤液中。可以发现, 通过离子交换作用, CPAM 将淤泥颗粒上的非专性吸 附Cd 和部分专性吸附Cd 解吸到弱双电层水中, 泥浆经真空抽滤后, Cd 解吸率可达60%以上, 而不加CPAM 的淤 泥中Cd 经真空抽滤后解吸率不到1%。

The effect s and influencing mechanism of CPAM w ith different ion deg rees, mo lecular w eights, and dosag es on the ad2 so rption and deso rptio n character istics of Cd in dredged sludg e wer e investig ated. Results showed that when the initial concen2 tr atio n o f Cd in dr edg ed sludge is 0. 5 Lg/ L, the Cd concent ratio n in the super nat ant fluid is less than 0. 1 Lg/ L under the natu2 r al sediment ation af ter the adding of CPAM, w hich is similar to that w ithout the adding of CPAM. However , under the conditio n of vacuum filtr atio n, the concent ratio n o f Cd in the filtrate can r each 0. 35 Lg/ L, and abo ut 64% o f so luble Cd desor bs fr om the sludg e par ticles into the filtr ate. The intro ductio n of CPAM can desorb the no nspecific adsor pt ion Cd and some specific adso rp2 tion Cd in the sludge particles into t he weak do uble electr ic water t hr ough the ion ex chang e. After the v acuum filt ratio n, the de2 so rption r ate of Cd cand r each mo re than 60%, inst ead of 1% w ithout the adding o f CPAM.