The CRI system has a good purification effect on domestic sewage and polluted river water. Compared with traditional sewage treatment methods, this technology has low cost (including construction and operation costs), good water output, and does not produce activity. Sludge, simple operation, strong impact load resistance and stable operation.
It is more suitable for use in the vast rural areas of our country, very suitable for use in small and medium-sized towns with weak technical management, and very suitable for use in domestic sewage treatment plants.
This technology is generally not affected by geological and geographical factors and can be used freely in the vast southern region. However, in the northern region, more standardized insulation facilities are required, so the investment is generally larger. The technical shortcomings are also more prominent, mainly occupying a large area. At the same time, there is a greater risk for water that may contain oil or suspended solids. There are risks in using this technology. Pre-treatment should be considered to strengthen defensive measures, such as flocculation and sedimentation, hydrolysis and acidification. , oil separation, air flotation, pre-aeration and other methods, once impacted, it is difficult to recover in the short term, or even an accident.
Artificial rapid osmosis lacks an ideal total nitrogen denitrification mechanism and has low total nitrogen removal efficiency. Under normal circumstances, it does not exceed 30% of the total nitrogen removal capacity, and it can operate for a long time in sewage with high ammonia nitrogen. The rear effluent is prone to produce weakly acidic effluent, and expensive special fillers need to be added in time to replenish the alkalinity. At the same time, total phosphorus treatment is only at the inorganic phosphorus adsorption level, and the adsorption efficiency is limited. Therefore, artificial rapid seepage technology is not suitable for high-phosphorus sewage treatment.
When the CRI system treats polluted river water in temperate areas, its hydraulic load process parameters can be above 1 m?/(㎡·d), but it is limited by the organic load, so the treatment load generally does not exceed 1.5 m?/(㎡·d). The original text of the "Detailed Accounting Rules for Total Emission Reduction of Major Pollutants during the Twelfth Five-Year Plan" issued by the Ministry of Environmental Protection stipulates: "(2) Decentralized treatment facilities in villages and towns should be designed and constructed in accordance with relevant technical specifications. Generally, activated sludge is used Or biological filter or biological contact oxidation + constructed wetland or land rapid infiltration or oxidation pond and other combined processes, the reduction amount will not be calculated. ”
< p> Therefore, artificial rapid seepage technology must be used in conjunction with traditional technology when used in domestic municipal sewage treatment facilities (mainly for urban sewage treatment plants and river water purification plants at all levels). For example: oxidation ditch, AO process, SBR or biological filter, contact oxidation process are first used in sewage treatment. After the pre-treatment, the artificial rapid infiltration (CRI) process is used in the deep treatment section. It is not only for the reliability of the sewage treatment plant to meet the standards. The protection can also meet the requirements of the Ministry of Environmental Protection’s local emission reduction political tasks, so as to avoid unnecessary policy constraints on local governments due to the inability to calculate emission reductions after construction is completed.