城市污水处理过程中会产生大量污泥，这些污泥是含水率极高的带负电荷的粒子群，为了降低污泥含水率，减少污泥体积，需要对污泥进行脱水。
There were a large number of sludge with much water and many negatively charged particle group during treating municipal sewage . The sludge should be dehydrated for reducing moisture content and volume of sewage sludge .
电荷群