Boiler sewage recovery and treatment process combined with reverse osmosis and chemical precipitation technology

Abstract

The invention relates to a boiler blow-down water recovery treatment process combined with reverse osmosis and chemical precipitation technologies. The boiler blow-down water recovery treatment process comprises the following steps of: regulating the temperature, pH value and suspended matter concentration of boiler blow-down water to meet inlet water requirements of a reverse osmosis system; then introducing the boiler blow-down water into the reverse osmosis system, and performing reverse osmosis treatment so as to obtain a dialysate and concentrated liquor, wherein the dialysate is used as a boiler primary demineralized water; and performing chemical precipitation treatment on the concentrated liquor by use of a coagulant and a flocculant, thereby obtaining a supernate, wherein the supernate is used as boiler raw water or make-up water for a water circulation system, so that the recovery treatment of boiler blow-down water is realized. Compared with the prior art, the boiler blow-down water recovery treatment process is capable of realizing complete zero-emission treatment of the boiler blow-down water, recovering high-quality water resources and saving the operation cost, and has the characteristics of general applicability to boiler blowdown systems, stable technical process, low cost and the like.

Description

technical field [0001] The invention belongs to the technical field of water pollution control, and in particular relates to a recovery and treatment process of boiler blowdown water combined with reverse osmosis and chemical precipitation technology, which is suitable for the treatment of boiler blowdown water systems of various pressure levels. Background technique [0002] With the rapid development of industry and agriculture and the rapid expansion of urbanization, the shortage of water resources in my country has become more and more prominent. To solve the problem of water shortage, it is far from enough to rely solely on opening up new water sources, and the cost of water intake is gradually increasing. Difficulties are also increasing. At the same time, the current use of water resources in my country is quite extensive. With the promulgation of new water-saving and energy-saving policies, we are objectively required to use the concept of circular economy to think ab...

AI Technical Summary

Problems solved by technology

In the process of removing phosphorus by calcium salt chemical precipitation, the pH of wastewater has a great influence on the removal effect of phosphorus precipitation. The higher the pH value, the better the effect of phosphorus removal. When the pH value of wastewater is 8.0, calcium carbonate CaCO 3 The formation of calcium hydroxyphosphate will obviously inhibit the formation of calcium hydroxyphosphate precipitate, and the phosphorus removal effect is poor, and when the pH value is 9.0, this inhibitory effect will be weakened

Therefore, in order to maintain a high removal rate of phosphorus in the effluent, it is usually necessary to add a large amount of lime to adjust the pH value of the wastewater to a higher value (10.0-11.0), which leads to a large consumption of chemicals and higher costs. The amount of mud has increased greatly, so the method of adding calcium salt is generally less used for chemical precipitation to remove phosphorus

[0009] The above chemical precipitation methods all show a certain degree of treatment effect in the targeted removal of phosphate. However, due to the many control conditions of the precipitation precipitation method, it is affected by factors such as pH, temperature, and the type, ratio, and concentration of the chemical agent. The constraints are obvious, and the effluent water quality is also difficult to control, especially for the treatment of a large amount of "clean" sewage in the boiler system. The chemical precipitation method alone not only affects the reuse quality of the treated effluent to a large extent, but also produces a large amount of waste water. Chemical sludge, increasing subsequent treatment costs

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