Polyaluminum chloride and polyacrylamide treatment of arsenic-containing wastewater Polyacrylamide is an organic water treatment agent, polyaluminum chloride is an inorganic flocculant, through the use of these two kinds of water treatment agent can be mixed to achieve better Wastewater treatment effect, especially for arsenic beneficiation water treatment, the effect is very good. Arsenic in nature mainly in the form of sulfide minerals, with the precious metal ore, non-ferrous metal mining and processing into the environment. Arsenic is a highly toxic substance that exists mainly in the form of arsenite ions (AsO2-) and arsenate ions (AsO43-) in the water, causing serious environmental pollution. China's highest allowable concentration of arsenic in surface water is 0.05mg / L. Mine wastewater contains more suspended solids, more turbid. With the extension of storage time, the concentration of arsenic in water decreases due to the sedimentation of suspended solids such as arsenic and dust, or the sedimentation of suspended solids with arsenic compounds. At present, several commonly used methods for the treatment of arsenic-containing wastewater at home and abroad mainly include sedimentation, flocculation, filtration, adsorption, oxidation, membrane method and biological method. Adopting polyaluminum chloride and polyacrylamide to treat arsenic-containing wastewater has the advantages of wide range of arsenic removal, high efficiency and environmental quality standard of surface water after purification. Effect of polyaluminum chloride dosage on arsenic removal As the dosage of polyaluminum chloride coagulant increases, the arsenic removal rate increases, but if the amount of the precipitating agent is too small or too large, the suspended solids in water will make the water slightly turbid . This is because when the amount of polyaluminum chloride is small, the amount of each small particle in the flocculation system is small, the flocculation and sedimentation can not be rapidly carried out, the suspended matter in the water increases, and the water body is slightly turbid. When the amount of the precipitating agent is too large, In a certain period of time can not be all flocculation settlement, but also makes the water increased suspended solids, water slightly turbid. Effect of polyacrylamide dosage on arsenic removal After alumiminium treatment, the arsenic removal rate in waste water is already very high. When a polyacrylamide is added to aid coagulation in the system, the removal rate of arsenic further increases, Achieve compliance emission requirements. With the increase of the amount of polyacrylamide, arsenic removal rate increases, but when the amount of polyacrylamide reaches a certain level, but to make the water suspended solids increased. The reason is that when the amount of polyacrylamide is suitable, colloidal particles are caused to collide with each other through bridging and crosslinking and accelerate the formation and precipitation of coagulation flocs, which aggravate the co-precipitation effect. When the amount of polyacrylamide is too much, Due to the repulsion between the molecules of the polyacrylamide itself used, some fine particles can not settle within a certain time, but suspended solids appear in the water.