Water treatment process is:
1, primary treatment-mechanical treatment section:
Mechanical (primary) treatment section including grids, sand sedimentation tanks, primary sedimentation tanks and other structures, in order to remove coarse particles and suspended solids for the purpose of the treatment of the principle of solid-liquid separation through the physical method to achieve the separation of pollutants from sewage, which is the commonly used sewage treatment.
2, secondary treatment - sewage biochemical treatment:
Sewage biochemical treatment belongs to the second level of treatment, in order to remove non-sedimentable suspended solids and dissolved biodegradable organic matter for the main purpose, the process composition of a variety of composition can be divided into the biofilm method and activated sludge method (AB, A/O, A2/O, SBR method, oxidation ditch method) Stabilization pond method, land treatment method and many other treatment methods.
3, tertiary treatment-depth treatment of water:
The water after secondary treatment will be de-nitrogenized, de-phosphorylated, and the residual pollutants in the water will be removed by activated carbon adsorption or reverse osmosis, etc., and disinfected with ozone or chlorine to kill bacteria and viruses, and then the treated water will be sent to the middle waterway to use it as a water source for flushing toilets, spraying the streets, and watering the green belts, industrial water, fire prevention and other water sources.
Expanded:
The impact of the environment of the water treatment process:
1, PH value:
The optimal pH range for microorganisms of the activated sludge system is 6.5-8.5, acid or alkaline environment is not conducive to the survival and growth of microorganisms, and when serious, it will cause the sludge floc to be destroyed, the bacterial colloid disintegration, and the treatment effect deteriorates sharply. The treatment effect will be deteriorated dramatically.
2, dissolved oxygen
When the dissolved oxygen in the environment is higher than 0.3mg/l, the parthenogenetic bacteria and aerobic bacteria are aerobic respiration; when the dissolved oxygen is lower than 0.2-0.3mg/l is close to zero, the parthenogenetic bacteria are transferred to the anaerobic respiration, and the vast majority of the aerobic bacteria basically stop respiration, while some of the aerobic bacteria (most of them are filamentous bacteria) may also be good growth, and occupy the advantage of sludge expansion in the system. After the dominance of the system often lead to sludge expansion.
3, temperature:
The effect of temperature on microorganisms is very wide, although in the high temperature environment (50 ℃ ~ 70 ℃) and low temperature environment (-5 ~ 0 ℃) are also active in some classes of bacteria, but the majority of microorganisms in the wastewater treatment of the optimal growth of the temperature range is 20-30 ℃.
Baidu Encyclopedia-Water Treatment Process