A kind of wastewater treatment method

Abstract

The invention relates to a wastewater processing method. The method comprises the following steps: step one, individually collecting ion exchange regenerated liquid and reverse osmosis concentrated water, which are generated during the process of high efficient reverse osmosis processing technology; step two, subjecting the collected ion exchange regenerated liquid to a high efficient reverse osmosis pretreatment, then adding Na2S to precipitate divalent cations, dehydrating sludge, and subjecting supernate to pretreatment; step three, processing the collected reverse osmosis concentrated water by a nano filtration technology so as to separate inorganic salts in the concentrated water, wherein the product is composed of divalent salts mainly composed of divalent ions in the nano filtration concentrated water side and monovalent salts mainly composed of NaCl in the nano filtration producing water side; step four, in the nano filtration concentrated water side, carrying out an evaporation and crystallization treatment to form sulfate and concentrated liquor, and processing the concentrated liquor at regular intervals; step five, in the nano filtration producing water side, carrying out salt concentration by using an ionic membrane. The provided wastewater processing method has the advantages of high processing efficiency, low cost, energy saving, and environment-friendliness.

Description

technical field [0001] The invention relates to a waste water treatment method. Background technique [0002] In the previous wastewater treatment requirements, it is generally required that the wastewater can be discharged after it reaches a certain discharge standard. With the increase of the country's environmental protection efforts, some industries with serious pollution, the country requires zero discharge of wastewater. That is, enterprises are not allowed to discharge water outside, and all wastewater will be reused after treatment. However, because wastewater generally contains a large amount of inorganic salts, this part of the substance cannot be decomposed and utilized. Therefore, a small part of wastewater is often left in the process of wastewater reuse treatment. This part of wastewater contains COD (chemical oxygen demand, Chemical Oxygen Demand) Higher, with higher salt content, it can no longer be reused. It can only be dried to convert the liquid into sol...

AI Technical Summary

Problems solved by technology

However, because this treatment process converts all the salt into a solid substance, a single salt cannot be used for utilization, resulting in a lot of waste. In addition, a large amount of solids produced must be treated, and there may be a possibility of becoming hazardous waste, which increases the Treatment costs, therefore, also affect the application of this treatment process