By testifying double-layer of granulated-slag and quartz sand, the effect of water-gas backwashing is superior to water backwashing on many aspects of avoiding mixing filtration media, reducing backwashing time and consuming water.

With optical turbidity instrument,the practical measurement is made about turbidity degree of backwash water in floatation tank,and then acquired experimental data of backwash water turbidity of each unit filter on the whole filtering tank.

Aiming at the problem of consuming much water in backwashing filtering media of Lan Zhou Rail-Way Plant of Water Supplying,which need reusing backwash water,the experimental researches of sedimentation ability of backwash water have been carried out.

Coagulation experiment study of backwashing wastewater in the groundwater works for iron and manganese removal;

By experiment, the coagulation effect, influence factors of the backwashing wastewater in the groundwater works for iron and manganese removal was studied, and the sludge sedimentation and dehydration performance was discussed, and their influence factors were investigated.

The filtering property of three common filtering media on the condition of air-water backwashing are compared based on the testing of the models.

In order to improve drinking water quality and minimize water consumption during backwashing, the siphon filter was modified to V-shape air-water backwashing filter in Xin’an Waterworks of Water Supply Corporation in Shengli Oil Field.

0 mm of filter materials is the best for water treatment,the feasible parameters of air-water backwashing process are proposed,i.

This paper puts forward a process management and control system for the air water backwashing of V-filter based on HLC-1 loop controller.