Energy-saving comprehensive chemical wastewater deep treatment system and treatment method thereof

Abstract

The invention discloses an energy-saving comprehensive chemical wastewater deep treatment system and a treatment method thereof. The system comprises a forward osmosis (FO) membrane concentration device and a multi-effect evaporator, wherein the FO membrane concentration device comprises one or more stages of airtight FO membrane exchange boxes, a sucked solution recycling device and a clear water recovering device; the sucked solution recycling device is connected with the stages of airtight FO membrane exchange boxes through electrical valves respectively; the clear water recovering device is connected with the sucked solution recycling device; the stages of airtight FO membrane exchange boxes are connected through liquid discharge electrical valves in sequence and connected with a mother liquid incineration furnace through overrunning electrical valves. The method is characterized in that for high osmotic pressure characteristic of comprehensive chemical wastewater, water resources are recycled while the comprehensive chemical wastewater is efficiently concentrated to generate electrical energy by preparing a sucked solution with relatively good colligative properties and utilizing osmotic pressure difference caused by colligative property difference of the solution; the automatic interlocking control is realized in a running process and the running mode can be adjusted according to different water feeding conditions.

Description

technical field [0001] The invention relates to an advanced treatment system and method for comprehensive chemical wastewater, belonging to the technical field of wastewater treatment. Background technique [0002] With the development of my country's industry, a large number of domestic industrial parks have sprung up. At present, there are nearly 7,000 industrial parks of various types, most of which are chemical parks. The park enterprises discharge a large amount of chemical wastewater. Due to the large number of chemical industries, the above wastewater Collectively referred to as comprehensive chemical wastewater. [0003] Comprehensive chemical wastewater has complex components and various types, and the refractory organic matter, heavy metals and some toxic pollutants contained in it are difficult to degrade under the self-purification of natural water bodies. If these pollutants are directly discharged into the water body without treatment, it will not only cause wa...

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Problems solved by technology

[0007] (2) Complex components

[0008] (3) Higher salt content

High salinity will have a strong inhibitory effect on biological activity, affect the degradation of organic matter, and even cause the collapse of biological systems

[0009] (4) Unstable water quality and quantity

[0011] Various treatment methods for comprehensive chemical wastewater have their advantages and disadvantages. Due to their strong operability and high treatment efficiency for refractory pollutants, physical and chemical methods are often used for pretreatment or advanced treatment of comprehensive chemical wastewater, but there are certain For example, coagulation sedimentation, activated carbon adsorption, membrane filtration and other methods only transfer the phase of pollutants, but do not achieve complete degradation of pollutants; the advanced oxidation method has high treatment efficiency and fast response, and has a significant effect in the treatment of refractory wastewater. However, this type of reactor has high manufacturing and operating costs and strict reaction conditions, so it is not suitable for upgrading and transforming existing wastewater treatment processes.

Similarly, most other physical and chemical methods have the disadvantages of large energy consumption and high investment and operation costs, which restrict their large-scale application in chemical wastewater treatment

[0012] The cost of biological treatment technology is low, and it is still the main treatment technology at present. However, due to the existence of a large amount of refractory organic matter and bioinhibitory substances in comprehensive chemical wastewater, problems such as low efficiency and unstable operation of the biological treatment system are often caused.

In order to improve the effect of biological treatment, measures such as prolonging the hydraulic retention time or diluting the raw water to reduce the influent load of the biological system are usually taken, but this method still does not achieve the desired effect and is not economical, so the following methods are usually used in engineering Biological treatment is the main body, physical and chemical methods are used as a combined process of pretreatment and advanced treatment, or some biological enhancement methods are adopted to improve the treatment effect of comprehensive chemical wastewater

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