What is the water treatment process

1. Commonly used water treatment methods
Natural precipitation to remove coarse particles in water
Coagulation and sedimentation Use coagulation agents to precipitate or clarify to remove colloids and suspended impurities in water, etc.
Filtration allows the water to pass through the fine-porous filter material layer to intercept and remove the remaining fine impurities after precipitation or clarification; or without precipitation, the raw water is directly dosed, coagulated, and filtered to remove colloids and suspended impurities in the water
Disinfection removes viruses and bacteria in water, ensuring drinking water sanitation and production water safety
Softening Reduce the content of calcium and magnesium ions in the water and soften hard water Source: Exam
Removal of iron and manganese to remove excess iron and manganese contained in groundwater so that the water quality meets drinking water requirements
2. Feedwater treatment process and applicable conditions (see Table 1K414021-2)
Common treatment process flow and applicable conditions Table 1K414021-2
Applicable conditions of process flow:
Simple treatment of raw water (such as screen filtration or disinfection) The water quality is better
Raw water-contact filtration-disinfection Generally used to treat lake water and reservoir water with low turbidity and chromaticity. Influent suspended matter is generally less than 100mg/L, and the water quality is stable, small changes and no algae reproduction
Raw water-coagulation, sedimentation or clarification-filtration-disinfection The conventional treatment process widely used in general surface water treatment plants is suitable for river water with turbidity less than 3mg/L. The turbidity of water in rivers and streams is often low, and the amount of sand in floods is large. This process can be used to directly filter the low-turbidity and non-polluting water without adding coagulant or across sedimentation.
Raw water-storage and pre-sedimentation-natural pre-sedimentation or coagulation sedimentation-coagulation sedimentation or clarification-filtration-disinfection of high turbidity water secondary sedimentation, suitable for large sand content, long sand peak duration, raw water after pre-sedimentation The sand content should be reduced to less than 1000mg/L. The small and medium water plants in the upper and middle reaches of the Yellow River and the high turbidity water treatment in the upper reaches of the Yangtze River mostly use secondary precipitation (clarification) processes, which are suitable for small and medium water plants, sometimes built behind the filter Clear water storage tank
Three, pretreatment and advanced treatment
In order to further play the overall role of the water treatment process, improve the removal of pollutants, improve and improve drinking water quality, in addition to conventional treatment processes, there are pretreatment and advanced treatment processes. To
1. According to different ways of removing pollutants, pretreatment methods can be divided into oxidation method and adsorption method, and oxidation method can be divided into chemical oxidation method and biological oxidation method. Chemical oxidation pretreatment technology mainly includes chlorine pre-oxidation and potassium permanganate oxidation, ultraviolet light oxidation, ozone oxidation and other pretreatments; biological oxidation pre-treatment technology mainly adopts biofilm method, and its form is mainly submerged biological filter, such as Carry out TOC biodegradation, nitrogen removal, iron and manganese removal, etc. Adsorption pretreatment technology, such as powdered activated carbon adsorption, clay adsorption, etc. To
2. Deep processing. At present, the most widely used advanced treatment technologies mainly include activated carbon adsorption method, ozone oxidation method, ozone activated carbon method, biological activated carbon method, photocatalytic oxidation method, and stripping method.