Approach
1.Physical processing
The method of separating and recovering undissolved suspended state pollutants (including oil film and oil beads) in the wastewater by physical action can be classified into a gravity separation method, a centrifugal separation method, and a sieve filtration retention method. The processing unit belonging to the gravity separation method has sedimentation, floating (air floatation), etc., and the corresponding processing equipments are grit chambers, sedimentation tanks, grease traps, air floatation tanks and their attachments. The centrifugal separation method itself is a treatment unit, and the treatment devices used are a centrifugal separator and a water separator. The screening and retention method has two processing units: grid screening and filtration. The former uses a processing device for the grid and the screen, while the latter uses a sand filter and a microfilter. The processing method based on the principle of heat exchange also belongs to the physical processing method, and the processing unit has evaporation, crystallization, and the like.
One method for removing organic matter from wastewater is activated carbon adsorption. Activated carbon treatment can be used together with the activated sludge process, in which powdered activated carbon is used. Powdered activated carbon absorbs substances that are toxic to microorganisms and eventually collects them together with the sludge. The main danger of the activated carbon process in wastewater treatment is that the spent activated carbon may always be present in the water.
2.Chemical treatment
A chemical treatment and mass transfer to separate and remove waste water from dissolved or colloidal conditions in wastewater or convert it into harmless substances. In the chemical treatment method, the processing units based on the chemical reaction generated by the dosing agent are: coagulation, neutralization, redox, etc.; and the mass transfer-based treatment units are: extraction, stripping, stripping , adsorption, ion exchange, electrodialysis and reverse osmosis. The latter two processing units are also collectively referred to as membrane separation techniques. The processing unit using mass transfer has both chemical and physical effects, so it can be separated from the chemical treatment method and become another processing method called physical chemistry.