In keeping higher total sludge concentration, suspended sludge mass entering into membrane separation with mixture liquid was low, thus decreased affect on membrane permeability.

With the structural modification of quartz sand filter in Daqing oil field, and using the suspended sludge filtration in treating oilfield wastewater, the good experimental results are obtained.

Indiana gave a permit to BP that allows it to increase emissions of ammonia and suspended solids (critics call it sludge) by 54% and 35% respectively.