How to improve the corrosion tendency of circulating water?
Formulate a reasonable concentration ratio and adjust the water quality to a slight scaling tendency. If the makeup water is mostly soft water from reclaimed water, communicate with the customer to find a water source with high hardness and high alkalinity that can be supplemented (e.g., reverse osmosis concentrated water). Recalculate the water quality of the comprehensive makeup water in proportion during the design, and adjust the circulating water quality in combination with the concentration ratio.
What are the main foulants on the membrane surface ？
1.Organic, colloidal and particulate fouling.
2.Scaling.
3.Bacterial and microbial fouling.
Key points for circulating water treatment of soft water quality in southern Guangdong, Fujian and Zhejiang?
The makeup water in these areas is low in hardness and alkalinity with strong corrosivity. The treatment direction is to increase the concentration ratio as much as possible to operate the circulating water with hardness and alkalinity greater than 150mg/L. The chemical formula is inclined to corrosion inhibition. For power plant systems with stainless steel as the main equipment, corrosion inhibition is not difficult, and the combination of 5584 and 5504 at a ratio of 1:1 is still selected.
What matters need attention when improving the hardness and alkalinity of circulating water by adding reverse osmosis concentrated water?
Conduct a full water quality analysis of the supplemented concentrated water, focusing on pH, conductivity, chloride ions, calcium hardness, total alkalinity, total iron, etc. Determine the appropriate supplementary volume based on the understanding of concentrated water quality, and adopt the principle of small and frequent additions in the initial stage to prevent a sharp increase in the corrosion and scaling tendency of circulating water caused by excessively high alkalinity/hardness and excessive addition of concentrated water. Adjust the dosage of corrosion and scale inhibitors in combination with the impact of concentration on water quality.
Colloids and particulate matter on the membrane surface can seriously affect the performance of the membranes. What are the typical observations？
Feed pressure increase.
Permeate flow decline.
Pressured drop increase.
Cleaning is not restoring the performance decline.
Configuration and function of intelligent chemical dosing equipment for circulating water?
It includes dosing pumps, control systems, and online instruments for pH, conductivity, ORP, chemical concentration (fluorescence), turbidity, COD, residual chlorine, etc. It continuously monitors water quality through online monitoring data, and interlocks to control the start and stop of dosing pumps by online determination of chemical concentration, so as to stably control the chemical concentration and save chemical dosage.
