卡拉胶、膨润土改性PVA包埋小球

对PVA+卡拉胶包埋小球和PVA+海藻酸钠包埋小球的性能进行比较,并首次使用PVA+卡拉胶+膨润土混合包埋材料制作包埋小球.结果表明,PVA+海藻酸钠包埋小球在制作过程中有一定的拖尾现象,红墨水到达小球中心的时间为80 min,6d可去除50％的COD;PVA+卡拉胶包埋小球更容易成球,而且红墨水到达小球中心的时间为50 min,6d可去除56％的COD.此外,在PVA+卡拉胶包埋材料中添加适量的膨润土可以将红墨水到达小球中心的时间由50 min缩短到30 min.因此,使用PVA+卡拉胶+膨润土的混合材料制作包埋小球是可行的.最后,通过包埋小球处理抗生素废水的正交实验,得出包埋材料中各组分的最佳配比:PVA浓度11％、卡拉胶浓度0.5％、膨润土浓度2.5％.在这种配比下,包埋小球对抗生素废水中COD的去除率可以达到65％左右.

PVA-immobilized beads modified by carrageenan and bentonite

The performance of PVA-carrageenan immobilized beads and PVA-sodium alginate immobilized beads were compared, and PVA-carrageenan-bentonite was used as immobilized material for the first time. The results showed that PVA-sodium alginate beads were tailing during production, the time of the red ink reached to the center of the beads was 80 mins, and after 6 days' treatment, 50% of COD was removed; while PVA-carrageenan beads had better sphericity, the time of the red ink reached to the center of the beads was 50 mins and after 6 days' treatment, 56% of COD was removed. Moreover, addition of bentonite into PVA-carrageenan could reduce the time of the red ink reached to the center of the beads from 50 mins to 30 mins. Therefrore, PVA-arrageenan-bentonite was feasible as embedded material. Finally, the orthogonal experiment results indicated that the best concentrations of PVA, carrageenan and bentonite in immobilized beads were 11%,0.5% and 2.5%,respectively, and under this condition, the COD removal efficiency was about 65%.