Power Consumption Control
At present, the power consumption of sewage treatment plants has reached more than 7 billion Kw.h/a, and the trend is increasing. The most important thing is to control the power consumption, among which submersible pumps and blowers are the key points.
(1) A 100,000-ton sewage treatment plant uses more than 10 submersible pumps, so it is of great significance to control pumps for energy saving and consumption reduction. Submersible pumps should be opened by soft start, which can effectively reduce the power consumption caused by excessive current during start-up. In addition, the submersible pump should be opened at a high level, which can reduce the head of the submersible pump and save energy.
(2) Use variable frequency adjustable blower. Blower consumption can be said to account for 40% to 62% of the total power consumption, so energy saving in blast aeration is very important. The water quality of sewage treatment plant is changing all the time. When the water quality is poor, it needs more dissolved oxygen, but when the water quality is good, it does not need too high dissolved oxygen. If the dissolved oxygen value remains unchanged (that is, the opening capacity of the blower remains unchanged), it wastes energy in vain, and if the dissolved oxygen is too high for a long time, it will even cause the disintegration of activated sludge, which will affect the effluent effect. In the sewage treatment plant with frequency conversion regulation, the opening degree of the fan can be automatically adjusted according to the setting value of the online dissolved oxygen meter in the aeration tank, so as to avoid unnecessary waste. In addition, the sewage treatment plant with staged water inflow can also stop aeration or weak aeration during the process of stopping water inflow, because the 12 hours of stopping aeration will not cause great impact on microorganisms.
(3) Continuous operation of some equipment such as coarse grille, fine grille, sand suction machine and primary settling tank scraper is of little significance to production, but it can shorten the service life of equipment, increase power consumption and failure rate, so this kind of equipment can adopt intermittent operation mode. For example, the liquid level difference between the front and back of the grille can be used to control the start and stop of the coarse and fine grille; the scraper can be opened according to the initial sludge concentration, such as opening the valve when the sludge concentration reaches 5%; other equipment can be opened regularly.
The consumption of medicines should be reduced as much as possible.
The sludge produced by municipal sewage treatment plant needs to be pretreated (i.e. conditioned) and conditioned with polyacrylamide (commonly known as PAM), an organic macromolecule flocculant. Under the premise of meeting the water content requirement of dewatered mud cake, the dosage of the sludge should be reduced as much as possible. Find the best dosage which can meet the requirements and reduce the cost of dosing. Operators should constantly explore rules, accumulate experience, avoid unfavorable factors and reduce drug consumption in practical work.
Controlling maintenance costs
After the sewage treatment plant has been in operation for a certain period of time, the maintenance of equipment appears to be particularly frequent, especially the imported equipment, whose expensive maintenance cost contributes greatly to the improvement of operation cost. In order to reduce maintenance costs, we should start from the following aspects:
(1) Strengthen the inspection of the equipment, so as to find and repair the faults early, so as to avoid greater losses.
(2) Do well the daily maintenance and maintenance of equipment, minimize the failure rate of equipment and prolong the service life of equipment.
(3) Control the cost of overhaul and renovation.
(4) Maintenance shall be carried out through the system of transfer of maintenance work orders.
(5) Statistical analysis of maintenance.
Reducing Material Cost
To reduce the material cost, we can adopt the method of price comparison purchase, which is beneficial to shorten the procurement cycle, save the procurement workload, reduce the inventory, reduce the capital occupation and reduce the cost of capital occupation.
Controlling labor costs
Establish and improve a scientific performance evaluation system to match the income of employees with the contribution of enterprises, and fully mobilize the enthusiasm of employees.
Control management and other costs
Although the proportion of this cost in the cost is small, effective saving can play a subtle role in reducing costs and improving the effectiveness of cost control.