DCS control method for adjusting alkaline waste water pH

Abstract

The invention relates to a DCS control method for adjusting an alkaline waste water pH. The method comprises 1, reading three parameter values, 2, calculating acid gas addition flow, 3, inputting the flow calculated value and 4, comparing the current detected pH and preset calculated pH, if the current detected pH is equal to the preset calculated pH, feeding the alkaline waste water subjected to pH adjustment into the next process so that the current process is finished, and carrying out the above circulation from the step 3. The DCS control method for adjusting the alkaline waste water pH realizes easy control of alkaline waste water pH adjustment, reduces a safety risk, prevents liquid acid corrosion and safety problems, reduces an operation cost and has substantial environment and economic benefits.

Description

technical field [0001] The invention relates to the field of wastewater treatment, in particular to a DCS control method suitable for adjusting the pH value of alkaline wastewater. Background technique [0002] At present, my country is the world's largest soda production base. As of 2014, the output of various types of soda has reached 42 million tons. A large number of soda production and soda consumption enterprises not only face the problem of high energy consumption, but also the alkali-containing wastewater generated in the production process The pH adjustment and the harm to the environment have become increasingly prominent. [0003] The traditional method of adjusting the pH value uses liquid sulfuric acid, nitric acid, and hydrochloric acid to drip, which inhibits the reproduction and growth of microorganisms in the downstream sewage treatment. The existing pH adjustment methods have the following problems: In the wastewater adjusted by the three acids, sulfate rad...

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Problems solved by technology

[0003] The traditional method of adjusting the pH value uses liquid sulfuric acid, nitric acid, and hydrochloric acid to drip, which inhibits the reproduction and growth of microorganisms in the downstream sewage treatment. The existing pH adjustment methods have the following problems: In the wastewater adjusted by the three acids, sulfate radicals will produce hydrogen sulfide during the biochemical reduction process of wastewater. Hydrogen sulfide is a highly toxic substance to microorganisms, which hinders the operation of sewage; Pipelines are corroded, and chlorine radicals higher than 1000mg / l have an inhibitory effect on microorganisms; thirdly, wastewater treated with nitric acid not only needs to consider the storage safety of nitric acid, but also needs to be treated by nitrification and denitrification after nitrate radicals enter the water body. Bring difficulty to sewage treatment process

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