Process for treating chemical wastewater by combination of membrane biological reactor (MBR), and ultrafiltration (UF) and reverse osmosis (RO) systems

Abstract

The invention provides a process for treating chemical wastewater by a combination of membrane biological reactor (MBR), and ultrafiltration (UF) and reverse osmosis (RO) systems, belongs to the field of energy conservation and environment protection, and mainly aims at organic wastewater which is discharged from chemical enterprises and has extremely high chemical oxygen demand (COD) concentration, high salinity and extremely large toxicity to microbes. The process comprises the steps as follows: firstly, the chemical wastewater is pretreated by an MBR membrane component reactor, wherein the chemical wastewater flows in a membrane component, organic matters in the sewage permeate the membrane selectively and are digested and degraded by the microbes, and an exposure head is arranged at the bottom of the reactor so as to ensure the concentration and the activity of the microbes in the reactor and further play the role of stirring; then, the wastewater treated by the MBR reactor is pumped to UF and RO membrane treatment systems by a circulating pump; the wastewater enters the UF and RO membrane treatment systems by the circulating pump and the high pressure wastewater is filtered by a UF membrane to remove suspended solids (SS) and large-particle dissolved organic matters in the wastewater, wherein the back flush can be realized by the UF membrane system and liquid waste is returned to the MBR reactor; finally, effluent from the UF enters the RO membrane treatment system by the high-pressure circulating pump so as to remove the salt in the water by reverse osmosis; and concentrated liquor is collected directly for subsequent treatment so that the treated water can reach the discharge standard or even the standard of reuse water.

Description

technical field [0001] The invention is mainly aimed at the fields of energy saving and environmental protection. Chemical enterprises discharge a large amount of organic waste water. The waste water has extremely high COD concentration, high salinity and great toxicity to microorganisms. The present invention particularly relates to an MBR, UF and RO system combined treatment process for chemical wastewater that can effectively treat the characteristics of chemical wastewater, so that the treated water can meet the discharge standard, and even reach the reuse water standard. Background technique [0002] my country is a major producer of chemical products, and a large amount of chemical wastewater is discharged. The concentration of organic matter in the wastewater is high, and it is difficult to biodegrade organic matter. Traditional biological treatment processes are difficult to achieve good treatment results. The advent of the MBR biological reaction membrane system in ...

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Problems solved by technology

[0003] Although a single MBR membrane reaction system can treat chemical wastewater with high concentration of organic matter very well, it has the following disadvantages: (1) The membrane flux is low, and the reactor must be increased to increase the water treatment capacity per unit time. quantity, greatly increasing operating costs

(2) The membrane system in the MBR membrane reactor is directly in contact with the microbial sewage mixture, which may easily cause membrane pollution and damage, reduce the service life of the membrane, and make it difficult to backwash

(3) The MBR membrane reaction system generally uses a membrane as the filter membrane, and there is no concentration buffer, which reduces the treatment effect of the system on sewage

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