Forced external circulating type efficient precipitation method and equipment based on addition of lime

Abstract

The invention provides a forced external circulating type efficient precipitation method based on addition of lime. The method is characterized in that turbid matters in water are efficiently deposited through a precipitation technology; lime is added to a coagulation tank, and the enriched sludge is returned to a flocculating tank, so as to obtain a mixed liquid formed by high combination of the returned sludge and line particles; the removal of the turbid matters and the organic matters in the water is strengthened under the depositing and netting and adsorption effects of externally-circulated and returned sludge and the chemical effect of hydroxyl ions of the lime, and moreover, calcium, magnesium and heavy metal ions in the sewage also can be removed; the shortcomings that in the conventional treatment process, COD (Chemical Oxygen Demand) and suspension solid treatment efficiencies are low, and the utilization rate of the added lime is low are improved; and high capacities of moving hard and heavy metals and organic matters are brought to the conventional precipitating technology. The sewage treated by the method provided by the invention has the characteristics of high outlet water quality, little medicine consumption and small occupation area, and can reduce the processing burden of the follow-up technology to the maximum. The forced external circulating type efficient precipitation method is higher in effect for treating common sewage, is specifically applicable to the process of processing the degradation-resistant COD and the hardness type sewage, and also can be used in the stage of deeply processing the sewage.

Description

technical field [0001] The invention relates to a sewage treatment method and equipment used therein. The method aims to provide a new type of external circulation high-efficiency sedimentation method and add lime to it to effectively improve the removal rate of suspended solids, COD, heavy metals and hardness in sewage. Background technique [0002] In the existing sewage treatment technology, the sedimentation equipment is an important link in the water treatment process. In this process stage, it mainly realizes the separation of mud and water, desalination, and removal of suspended solids. Therefore, its operating status directly affects the quality of effluent water. Traditional sedimentation tanks often have problems such as large footprint, low treatment efficiency, unstable effluent quality, and separation of coagulation and sedimentation processes. [0003] A certain concentration of sludge backflow can increase the sedimentation velocity of the interface layer to...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is that in the process of sewage treatment, especially refractory COD and hardness sewage treatment, ordinary coagulation sedimentation tanks have a low removal rate of COD and suspended solids, resulting in subsequent operating costs of advanced oxidation, biochemical and other process stages High, not up to the reuse standard

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