金属氢氧化物包被砂过滤柱吸附与去除水体中的微生物

ADSORPTION AND REMOVAL OF MICROORGANISMS FROM WATER BY COLUMNS CONTAINING SAND COATED WITH METALLIC HYDROXIDE

以氢氧化铁与氢氧化铝原位沉积包被砂作介质的过滤柱 ,用于去除脱氯自来水中人为污染的高浓度脊髓灰质炎病毒PV1、脆弱拟杆菌噬菌体B .fp和大肠杆菌E .coli.结果显示 ,包被修饰砂颗粒表面Zeta电动势由原来的 - 4 2 .8mV上升到 5 4 .7mV ,并因此提高了对微生物的吸附去除能力 .修饰砂过滤柱经 12 .5d连续过滤 30 0L水样后 ,仍可使进水微生物浓度分别高达n(cfu) /mL-1=5 .2× 10 6、2 .4× 10 5、2 .3× 10 5的E .coli、B .fp和PV1去除 92 %、97.2 %和 99.6 % .而未修饰砂柱 ,在相同条件下仅分别去除 5 3%、5 9%和 70 .6 % .修饰砂柱可在较大pH变化下稳定高效地去除微生物且在中性条件下效果最佳 ,这与未修饰砂柱明显不同 .扫描电镜显示 ,两种砂具有明显不同的表面结构 .修饰砂柱流出液中检测不到用于包被的铁、铝金属 ,说明氢氧化铁、氢氧化铝修饰物同砂结合牢固并因此提高了砂过滤柱的使用寿命 .修饰砂过滤介质可为饮用水处理提供更为安全可靠的去除病原微生物方法 .图 4表 4参

Using filter columns containing sand coated by in situ precipitation of ferric and aluminum hydroxides to remove the seeded microorganisms of Poliovirus 1(PV 1),bacteriophage infecting Bacteroides fragilis (B.fp) and Escherichia coli from dechlorinated tap water were studied in this paper. The results showed that the coated sand changed the zeta potential from -42.8 mV to +54.7 mV, and significantly improving removal of the seeded microorganisms. The modified sand column can still remove 92% Escherichia coli,97.2% B.fp and 99.6% PV 1 after 12.5 days continuous filtration and passed through total 300 liters water sample, while the untreated sand column could only removed 53%,59% and 70.6%,respectively. The columns containing modified sand efficiently removed microorganism at various pH values and the optimum pH was 7.0, while unmodified sand column did not. The surface construction of modified sand was obviously different from the untreated sand under the scanning electron microscope. The metal used for coating sand could not be detected in the effluents that indicated the coatings were stable. The results of these experiments shown the modified sand by metal hydroxide can provide a higher removing pathogen microorganism's efficiency way for the traditional drinking water treatment craft. Fig 4, Tab 4, Ref 19