First, the physical solution
Physical solution refers to changing the treatment method of sewage water according to the action of physical force or mechanical equipment force.
Physical solutions include: mountain separation, precipitation, filtration, etc. Physical methods mainly include removing large suspended solids and residues, concentrated feed sediments, pig urine and chemicals that can block or damage pipelines and centrifugal pumps, as well as reflective substances dissolved by organic chemistry, and activated sludge process or biofilm transformed by biological dissolution of sewage.
Second, the organic chemical solution
The solution of organic chemistry is to use the efficacy of chemical changes to remove residues in water.
Organic chemical solutions include: concrete, disinfection and sterilization, neutralization, etc. The goal of sewage organic chemistry is: soluble harmful substances in sewage, such as organic compounds with pH value and various organic solutions.
Third, biological solutions.
Biological solution is a kind of chemical substance that can dissolve and transform environmental pollution in sewage under the catalysis of enzyme and the basic metabolism of microorganism.
1, anaerobic fermentation biological solution technology:
In the biological solution of anaerobic fermentation, facultative bacteria and anaerobic fermentation bacteria can dissolve and stabilize organic matter without molecular structure oxygen and binding oxygen standards.
Hydrolysis acidification. The key of hydrolytic acidification includes the following parts:
(1) regulating pool
Generally, it is a rectangular frame or ring, and the aspect ratio of hydrolytic acidification economic development is generally 4 ~ 6m m. In addition, hydrolysis and acidification can be separated, and the volume of each unit is reduced after separation, which can improve the symmetry of water distribution and is beneficial to maintenance and overhaul.
(2) Water distribution system
Common water distribution methods include: one pipe with one hole, one pipe with porous structure, and water distribution.
(3) Sewage collection equipment
The effluent from hydrolysis and acidification can be collected by using triangular weir plates on the water surface.
Hydrolytic acidification can transform macromolecules into micromolecule hydrochemistry, and cyclic structure into reticular structure, which further improves the BOD/COD ratio of sewage, enhances the biodegradability of sewage, and creates an excellent natural environment for subsequent disinfection and sterilization. Hydrolysis can improve the biochemical characteristics of sewage, reduce the pH value of sewage, reduce sludge production, and create resource advantages for subsequent aerobic biological solutions.
2. Upflow Anaerobic Sludge Bed Tubular Reactor (UASB)
Upward anaerobic sludge bed tubular reactor was developed by Spanish expert Professor Lettinga in 1972 and designed in 1977. Because a large amount of anaerobic fermented granular sludge can be formed in the tubular reactor, the load of the tubular reactor is very large. For high-concentration general organic chemical wastewater, when the temperature is about 30℃, the load can reach 10-20k cod/(m3d).
Compared with other biofilters, UASB process has a series of advantages: (1) The biomass of sludge bed is large; (2) the capacity load is high, the residence time of sewage in the tubular reactor for hydropower generation is short, and the required pool capacity is greatly reduced; (3) The mechanical equipment is simple, the actual operation is convenient, and there is no need to set up a sludge reflux device, add fillers and set up mechanical equipment stirring equipment, so the project cost is more cost-effective, the management is convenient, and there is no blockage problem.
3, anaerobic fermentation biofilter
Anaerobic fermentation biofilter is a sealed reservoir, in which fillers are placed. Microorganisms adhere to the filler, and the average residence time can be as long as 100d. The filter material can be fist-shaped stone filter material, such as gravel and river pebbles. The particle size is about 40mm, and plastic filler can also be selected. Plastic filler has high porosity and light weight, but it is expensive.
4. Activated sludge
Activated sludge process is the most widely used aerobic biotechnology in sewage treatment at present, and it is also a promising sewage treatment technology. In recent decades, the scientific research on the principle of biological reaction and purification treatment has obtained a long-term development trend, and the production process has gradually improved and achieved fruitful results. Activated sludge is suitable for large-scale and high-concentration sewage.
Activated sludge is the key way to solve the biological problems of sewage by activated sludge method. Activated sludge is an inclined plate sedimentation tank similar to sludge produced after aerobic microorganisms propagate for a certain period of time. It inhabits methanogenic bacteria and has strong adsorption and air oxidation ability to organic matter.
5, activated sludge treatment technology
Activated sludge process is a variant of activated sludge, and its hydrolysis and acidification tank is a closed channel, so it is different from traditional activated sludge in the process of hydropower generation. It is the end-to-end channel of hydrolysis and acidification pool of circulating system, and sewage seeps into it to be purified. The original air oxidation channel is not completed by concrete structure, but a soil channel with various slope protection schemes, which is an intermittent seepage and intermittent hydrolysis acidification pool. From this point of view, the activated sludge process is the first one.
Technical characteristics of activated sludge process: The activated sludge process uses a continuous circulation reactor (CLR) as a bioreactor, in which the solution is continuously circulated in a closed hydrolytic acidification tank. Activated sludge process is generally applied under the standard of delayed hydrolysis acidification tank. Activated sludge process uses hydrolytic acidification tank with azimuth control and stirring equipment to transfer advection rate to the chemicals in the reaction tank, so that the stirred liquid can circulate in the system in a closed way.
6. Biofilm method
Biofilm method is a method to solve organic chemical wastewater by using microorganisms (biofilm) attached to the surface of some solid objects. Biofilm is an ecosystem composed of aerobic bacteria, Pseudomonas aeruginosa, facultative bacteria, bacteria, coelenterates and algae plants with high aspect ratio. The solid substances attached to it are called filter materials or media. Biofilm can be divided into celebration layer, nest fire layer, adhesion waterproof layer and fitness waterproof layer from the filter material. The basic principle of biofilm method is that the biofilm firstly absorbs and adheres to the organic matter in the water-resisting layer, and the organic matter is dissolved by the pit fire bacteria in the pit fire layer, and then enters the anaerobic layer for anaerobic dissolution, and the moving water-resisting layer washes away the fragile biofilm to grow and develop new biofilm, so as to achieve the purpose of purifying and treating sewage in a reciprocating way.
7, biological circulating fluidized bed
Biological circulating fluidized bed refers to a building with sand (or long-flame coal, activated carbon, etc.) as the carrier. ) As a filler and a biofilm medium, sewage flows through the sand bed from bottom to top to fluidize the medium layer, so as to increase the total contact area between biofilm and sewage in unit time and provide enough sacrifice, and strengthen the biological treatment of sewage by using the boiling of filler. The area of the filler in the building is over 3300m2/m3, and the biofilm growing on the filler rarely falls off, so the secondary grit chamber can be omitted.
The total dissolved solid concentration of the solution in the bed reaches 8000-40000 mg/L, and the oxygen utilization rate exceeds 90%. According to the test results of semi-production operation, the sludge load of BOD and nitrogen exceeds 90% when the residence time of Wan Li cleaning bed is 16-45 minutes. At this time, the particle size of the filler is 65438±0mm and the water content is 65438 000%. Biological fluidized bed treatment technology has high efficiency, small floor space and low engineering investment. In the United States, Japan and other countries, it has been used for advanced treatment of nitrification and denitrification of sewage, secondary treatment of sewage and other phenol-containing chemical wastewater and pharmaceutical industry.
8, biological contact air oxidation method
Biological contact air oxidation is an efficient sewage treatment process, which is dominated by biofilm attached to media (alias filler) to purify and treat organic chemical wastewater. Biofilm process has the characteristics of activated sludge and has the advantages of activated sludge process and biofilm process. Under biochemical standards, it has achieved excellent economic benefits whether it is used to solve chemical wastewater, aquaculture wastewater or domestic sewage. This treatment technology is widely used in sewage treatment systems in various fields because of its advantages of high efficiency, environmental protection and energy saving, small floor space, impact load resistance and convenient operation and management.