Recirculated cooling water nanofiltration ion exchange softening micro-basification method

Abstract

The invention discloses a method which is suitable for softening and dealing with industrial circulating cooling water by micro-basification. Nanofiltration process equipment is adopted for removing the multivalent ions such as Ca<2+>, Mg<2+>, SO4<2+>, and the like, in the water and some Na<+> ions are preserved, or the combination of cation-exchange resin weak-acid and nanofiltration is adopted for removing the multivalent ions such as Ca<2+>, Mg<2+>, SO4<2+>, and the like, in the water and some Na<+> ions are preserved; anion resin of OH-type / CO3-type / HCO3-type is adopted for removing the left superacid anions in the water, and the superacid anions are exchanged by OH<-> / CO3<2-> / HCO3<->, and the producing water is alkaline. The alkaline producing water reacts with the CO2 in the air to realize chemical equilibrium, and dilute solution with buffering is formed, the pH value of the circulating cooling water is adjusted to alkalescency ranging from 8.3 to 9.2, and softening and micro-basification treatment of the circulating cooling water is realized. The method of the invention can realize that various additionally added chemical agents such as antiseptic, corrosion inhibitor, scale inhibitor, water stabilizer, bactericidal algicide, and the like, are avoided for use in the circulating cooling water system, and has the technical effects of corrosion prevention, scaling prevention and microbial contamination prevention as well as comprehensive economic benefit that discharge of enriched water and chemical substance is reduced.

Description

technical field [0001] The invention specifically relates to a treatment method for nanofiltration ion exchange softening and slight alkalinization of industrial circulating cooling water, which belongs to the technical field of environmental engineering and also belongs to the technical field of chemical engineering. Background technique [0002] In the circulating cooling water system with the largest water consumption in industry, the most common problems are corrosion, scaling, microbial pollution, and concentrated water discharge pollutes the environment and wastes water resources. The most common hazards of the three major problems are: corrosion, which causes the mechanical properties of metal pipes to decline or even functional damage, and the deposition of corrosion products affects the heat transfer performance of the cooler; fouling, which leads to increased thermal resistance, reduced heat transfer performance, reduced flow cross-section, and Increased flow energ...

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Problems solved by technology

Chlorine is a commonly used agent, but the chlorine addition method is not suitable for controlling the growth of mussels in the circulating cooling water system (Sanjeevi Rajagopal, Gerard Van derVeldea, Marinus Van der Gaaga, Henk A. Jenner. How effective is intermittent chlorination to control adult mussel fouling in cooling water systems[J].Water Research 2003, (37):329-338); for the control of pathogens (Legionella), chloramine trihydrate T (Nazmiye OzlemSanli-Yurudu, Ayten Kimiran-Erdem, Aysin Cotuk. Studies on the efficacy of Chloramine Ttrihydrate(N-chloro-p-toluene sulfonamide) against planktonic and sessile populations of different Legionella pneumophila strains[J].Int.J.Hyg.Environ.-Health 2007,(210),147-153) , but the control dose of planktonic and fixed microorganisms must be considered at the same time; it is also reported that electrolytic silver, copper and a certain amount of chloride ratio are used to control sulfate-reducing bacteria and Escherichia coli in the cooling system (Susana Silva Martìnez, Alberto Alvarez Gallegos, Esteban Martìnez, Electrolytically generated silver and copper ions to treat cooling water: an environmentally friendly novel alternative [J]. International Journal of Hydrogen Energy, 2004, (29): 921-93)

Excessive oxidizing biocides have an impact on the corrosion protection of the system; various biocides have certain toxicity to varying degrees

[0006] The existing anti-corrosion, anti-scaling and anti-microbial pollution methods of industrial circulating water systems based on adding chemical agents cannot fundamentally solve the problems of adding chemical agents themselves and the resulting waste of water resources and environmental pollution.