In winter, the difficulty of sewage treatment in Inner Mongolia is increased, which is not conducive to sewage treatment. Therefore, when entering winter operation, it is necessary to strengthen its own operation management, deal with the unfavorable factors of winter operation, and ensure the efficient operation of the sewage plant in winter, so as to stably meet the standards and reduce emissions in full. In combination with previous water intake conditions and winter operation experience, the following operation methods are summarized to strengthen and optimize the operation management of the sewage treatment plant, and ensure that the sufficient amount of sewage is treated and the quality of the effluent water reaches the standard.
Strengthen the whole process management of sewage plant operation
Start from the details to ensure that each sewage treatment unit fully performs its due function. Failures and problems that arise should be discovered, analyzed, and resolved in a timely manner. Avoiding small problems and small failures that remain unresolved, dragging into big problems and affecting the stable operation of the entire system.
Special attention must be paid to the abnormal operation of the grille, sand settling tank, hydrolytic acidification tank, sludge dewatering machine, etc., which will increase the burden on the biochemical treatment system, cause the biochemical system to operate abnormally, and cause the problem of unstable water discharge. These conditions require Get enough attention and improve it. The sewage treatment plant should combine the specific conditions of the biochemical system such as the operation rules of its own process operation, the characteristics of the sludge, and the degradation and change laws of the pollutants; and the influent water quality, daily changes in the amount of water, and monthly changes. Through appropriate process optimization and adjustment, ensure sufficient treatment of sewage and effluent water quality to meet standards, and at the same time save energy and reduce consumption to optimize operating costs.
Adjusting operating parameters
In winter, the wastewater treatment plant generally has a high influent concentration, low water temperature, weak activated sludge activity, and slow response speed. The Inner Mongolia sewage treatment plant needs to adjust its production and operation parameters based on its own process and water intake characteristics.
Guaranteed nitrogen removal effect
In the process of biological denitrification, nitrogen-containing compounds undergo the following reactions one after another under the action of microorganisms: ammoniation reaction, nitrification reaction, denitrification reaction, and finally detach from the sewage in the form of N2.
The suitable temperature for the nitration reaction is 20-30 ° C. When the temperature is lower than 15 ° C, the nitration rate decreases, and it stops completely at 5 ° C. The suitable temperature for denitrification reaction is 20 ~ 40 ℃. When the temperature is lower than 15 ℃, the proliferation rate and metabolic rate of denitrifying bacteria decrease. The temperature of sewage in Northeast China in winter is about 10 ℃ or even lower, which is far from the optimal temperature of nitrifying bacteria and denitrifying bacteria, which has a great influence on the nitrogen removal efficiency.
Controlling sludge expansion
During the low-temperature operation in winter, sludge swelling can easily occur due to reduced sludge activity and abnormal process operation.
The sludge expansion at this time has three significant characteristics: one is the extremely high incidence, and 60% of urban sewage treatment plants have sludge expansion every year; the second is universal, Inner Mongolia sewage treatment is in various types of activated sewage This problem exists in the sludge process, even in intermittent aeration tanks that are least prone to sludge swelling; the third is serious harm, which not only causes sludge loss and effluent suspended solids (SS) exceeding standards, but also greatly reduces Processing capacity.
Once sludge expansion occurs, it is difficult to control or it takes a considerable amount of time to recover. For sludge swelling, appropriate sludge load should be controlled and should not be too low. The anaerobic zone can use the function of biological selection to inhibit the production of filamentous bacteria and avoid sludge swelling. Process operators should understand the sludge properties in a timely manner. When the SVI exceeds 150, sufficient attention should be paid. Chemicals can be added for control if necessary. The synthetic high-molecular-weight cationic polymer has a better effect on controlling sludge swelling, and has little effect on sludge production, but the cost is high. In some cases, the addition of inorganic flocculants (such as lime or ferric chloride) is also effective, but it will greatly increase the sludge production and bring certain difficulties to subsequent sludge treatment. In addition, adding soil and fiber is also suitable for some industrial wastewater treatment (such as papermaking wastewater), but this is only a short-term behavior.