褐煤热解半焦在污泥调质与深度浓缩脱水中的应用

Applications of lignite semi-coke on modifying and deep concentrated dewatering of sludge

为解决当前污泥脱水难的问题,以褐煤热解半焦作为污泥调理剂对污泥进行调质处理,并采用污泥重力浓缩脱水的实验方法探讨了褐煤半焦对污泥调质与深度浓缩脱水的影响。结果表明:用半焦对污泥进行调质,能够改善污泥的浓缩脱水性能、沉降性能以及浓缩污泥的机械脱水性能,当100 g污泥中加入2 g半焦时,浓缩污泥的含水率由调质前的91.13%降低至调质后的78.05%,浓缩污泥经真空抽滤后所得滤饼的含水率由调质前的65.00%降低至调质后的49.50%。污泥浓缩前20 min内,污泥的平均沉降速率由调质前的2.67 mL/min提高至调质后3.25 mL/min。通过污泥调质前后的粒度分析和半焦的扫描电镜图像分析,探讨了半焦对污泥调质与深度浓缩脱水的机理,其机理主要表现在半焦对污泥的吸附作用及半焦对污泥亲水性能的消弱作用。

In order to solve the current difficulty of sludge dewatering, the sludge was modified by semi-coke which was the pyrolysis product of lignite. The lignite semi-coke＇ s effect on modifying and deep concentrated dewatering of sludge was explored by the method of gravity concentrated dewatering. The results show that the dewatering property, the settling property and the mechanical dewatering property of sludge are improved greatly through adding semi-coke into the sludge. When 2 g semi-coke was added into 100 g sludge ,the water content of concentrated sludge is reduced from 91.13% to 78.05% after modified treatment. What＇ s more, the water content of filter cake is reduced from 65.00% to 49.50% by vacuum filtration. In 20 minutes, the average sedimentation rate of sludge is increased from 2.67 mL/min to 3.25 mL/min. This study explored the mechanism of semi-coke on the modifying and deep concen- trated dewatering of sludge. The mechanism mainly manifest in semi-coke＇ s adsorption on sludge and weakening hy- drophilic properties of sludge.