Method, device and system for treating low-turbidity surface water

Abstract

The invention provides a method, equipment and a system for treating low-turbidity earth surface water. The method for treating the low-turbidity earth surface water includes steps of carrying out coagulation reaction and sedimentation on raw water with added coagulants to separate sludge from the raw water; distributing the sludge obtained by means of sedimentation, carrying out acid activation on the partial distributed sludge by HCl solution and discharging the other distributed sludge; adding the sludge which is already subjected to acid activation by the HCl solution into the raw water. The coagulants are polyaluminum chloride or aluminum sulfate. The method, the equipment and the system have the advantages that the usage of the newly added coagulants can be reduced; the problem of poor coagulation effects due to low turbidity of existing earth surface water can be solved; particularly, the coagulants can be separately added into the raw water twice, a step for stirring the raw water at the high speed is additionally carried out between two procedures for adding the coagulants, accordingly, flocculation, crushing and re-flocculation procedures can be carried out on flocculating constituents in the water, the sweep flocculation efficiency can be improved, and effects of treating the low-turbidity earth surface water further can be improved.

Description

technical field [0001] The invention relates to the technical field of water treatment, in particular to a method for treating low-turbidity surface water, equipment for treating low-turbidity surface water, and a system for treating low-turbidity surface water. Background technique [0002] With the increasingly serious water pollution and the shortage of groundwater resources, more and more areas use surface water such as lake and reservoir water as drinking water sources, and most of these water sources have low turbidity. Low turbidity brings the following technical problems: First, the impurities in low turbidity water are mainly small colloidal dispersion systems dissolved in water, and the particle size of the colloids is uniform, and the dynamic stability is very strong. The negative charge is also less, and the coagulant needed to achieve electrical neutralization is also less. The flocs formed are small, light, loose, and have poor sedimentation properties. They ar...

AI Technical Summary

Problems solved by technology

Low turbidity brings the following technical problems: First, the impurities in low turbidity water are mainly small colloidal dispersion systems dissolved in water, and the particle size of the colloids is uniform, and the dynamic stability is very strong. The negative charge is also less, and the coagulant needed to achieve electrical neutralization is also less. The flocs formed are small, light, loose, and have poor sedimentation properties. They are easy to penetrate the filter layer and affect the water quality of the effluent. The treatment effect of large dosage is not good, but colloidal protection, that is, the phenomenon of colloid re-stabilization will appear; secondly, it is not appropriate to increase the velocity gradient in order to increase the particle collision rate, which will break the generated flocs and make the subsequent The sedimentation effect is reduced

Low turbidity water is a special water quality that is often encountered in water purification projects. The conventional coagulation-sedimentation process in water purification plants is difficult to meet the requirements of subsequent treatment structures (sand filters) for influent water quality.

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