Composite flocculating agent for treating urban sewage

Abstract

The invention discloses a composite flocculating agent for treating urban sewage, which belongs to the field of environmental protection and particularly relates to a composite flocculating agent fortreating urban sewage. The components of the composite flocculating agent of the invention are kieselguhr and polyaluminium chloride (PAC) in a weight ratio of 50-100:10-20. For each ton of waste water, 10 to 20 grams of kieselguhr and 50 to 100 polyaluminium chloride are added. The kieselguhr has strong absorption capacity and excellent COD, BOD, SS and total phosphorus absorption capacity. The polyaluminium chloride is added to generate a large amount of floc particles in solution of waste water and reduce the color of water.

Description

technical field [0001] The invention belongs to the field of environmental protection, in particular to a composite flocculant for treating urban sewage. Background technique [0002] The discharge of urban domestic sewage has caused serious environmental pollution. The nature of the city, its existing drainage system, air temperature, water resources and its level of economic development all affect the characteristics of urban wastewater. At present, the main characteristics of urban sewage in our country are: (1) the urban sewage with low organic matter concentration in waste water causes difficulties in biological treatment; (2) the biodegradability of waste water is poor. Therefore, after treatment, the organic matter left in the wastewater and entering the municipal pipe network is often difficult to biodegrade, and the B / C value of the wastewater is low. Therefore, the biodegradability of urban sewage containing a large amount of industrial wastewater becomes poor, wh...

AI Technical Summary

Problems solved by technology

Physicochemical method is good for removing chroma, heavy metals, phosphorus, but not ideal for nitrogen and organic matter removal

The biochemical method has a good removal effect on organic pollutants, nitrogen and phosphorus, but the removal rate of COD is low, the decolorization effect is poor, and a large amount of sludge will be generated, causing secondary environmental pollution

The general biochemical method requires that the biodegradability of wastewater is good, the proportion of various nutrients is coordinated, the concentration is appropriate, and the concentration of substances that inhibit biological growth is not higher than the range that microorganisms can bear. Therefore, for the wastewater in some cities at present, it may be due to the Due to a large amount of biological inhibitors or excessive fluctuations in water quality and quantity, the operation of the biological treatment system is sometimes not normal

Moreover, the biochemical method has high requirements on temperature. At low temperature, the activity of microorganisms will become lower, and some may even completely lose their activity, which will cause some biochemical treatment units to fail to operate normally.