Industrial technology for sewage treatment

3 Chemical assisted biological phosphorus removal

Due to the poor stability and flexibility of biological phosphorus removal, easily affected by carbon sources, pH value and other factors, the phosphorus content of the effluent often fails to meet the requirements of the national emission standards, and the stability of the biological phosphorus removal process can be improved by additional chemical precipitation. The research on chemical combined biological phosphorus removal technology is a hot topic. Among them, the research of the side-flow phosphorus removal (Phsostrip) process has attracted much attention, which can ensure that the phosphorus effluent value is below 1mg/L, although it cannot reach the national first-class A standard, but from the perspective of the stability of the phosphorus removal process, phosphorus removal efficiency, the convenience of the final disposal of sludge and the indirect saving of operating costs, there are incomparable advantages of other phosphorus removal processes

4. Recovery of phosphorus from sewage

Guanite (MgNH4PO4·6H20) precipitation method is used for phosphorus removal, this method can remove and recover phosphorus and nitrogen two nutrients, especially in some wastewater containing phosphorus and nitrogen, the application of guanite precipitation method to achieve phosphorus recovery in such wastewater only need to add magnesium source in the wastewater and adjust the pH properly, so it is more convenient. Struvite is a kind of excellent quality phosphate fertilizer, 100m3 sewage can be crystallized 1 kg struvite, if all countries are sewage struvite recovery, you can get 63,000 t of phosphorus (P2O5) per year, thus saving 1.6% of phosphate mining. Studies have shown that phosphorus recovery from sludge can reduce the dry solid mass of sludge, and the ash content generated by sludge incineration after phosphorus recovery will also be significantly reduced, and the sludge volume generated by struvite phosphorus removal process is very small, only 49% of the sludge volume generated by chemical phosphorus removal.

Cyclic intermittent aeration

The level of economic development in China varies greatly from place to place, and the cities with lagging economic development cannot devote a lot of funds to sewage treatment. Therefore, how to use limited funds to reduce environmental pollution is a problem faced by many city governments. In terms of sewage treatment, until recently, some cities also used first-level or first-level enhanced treatment technology, and the effluent did not meet the requirements of the national second-level discharge standards for the removal of organic pollutants. The cyclic intermittent aeration process gives full play to the advantages of high efficiency of high-load oxidation ditch treatment, and makes full use of the good characteristics of the effluent from the sequencing batch activated sludge sewage treatment process to ensure that the effluent of the system meets the requirements of the national sewage discharge standard in removing organic pollutants. The cost of investment and operation is about 30% lower than that of the secondary biological sewage treatment system which usually removes organic pollutants, and it is a process technology suitable for China's current sewage treatment requirements.

Rotary contact oxidation

Rotary contact oxidation wastewater treatment technology is a new generation of aerobic biofilm treatment technology developed on the basis of biological turntable technology and the advantages of biological contact oxidation technology. Rotary contact oxidation wastewater treatment technology and complete equipment provide a simple and reliable wastewater treatment method. The rotating shaft in the whole sewage treatment system is the only rotating part, and once the machine fails, the general mechanical personnel can carry out maintenance. The biomass of the system is automatically compensated according to changes in the organic load. The microorganisms attached to the turntable are living, and when the organic matter in the sewage increases, the microorganisms increase, and conversely, when the organic matter in the sewage decreases, the microorganisms decrease. Therefore, the working effect of this sewage treatment system is not easily affected by sudden changes in flow and load and power outages. Operating costs are low, and only one-eighth to one-third of the power consumption of other aerated sewage treatment systems. The footprint is only half that of the conventional activated sludge process. Because there are many kinds of microorganisms growing in the biological system, it can effectively treat all kinds of difficult to degrade industrial sewage.

Continuous cycle aeration

The Continuous Cycle Aeration System is a continuous water inlet SBR aeration system. The wastewater treatment process CCAS is improved on the basis of SBR (Sequencing Batch Reactor). CCAS wastewater treatment process does not have high requirements for wastewater pretreatment, and only has a mechanical grille with a gap of 15mm and a sand settling pond. The core of biological treatment is the CCAS reaction tank, in which the functions of phosphorus removal, nitrogen removal, degradation of organic matter and suspended matter are completed, and the effluent can be discharged up to the standard.