1 Proposed issue
According to the "three simultaneous" principle, a sewage treatment station for printing and dyeing wastewater is installed and installed, and its core equipment is aerobic biochemical (activated sludge) SBR. The process is shown in Figure 1.
From the practice after putting into operation, the device can meet the standard (cod <=110mg/1) in the appropriate microbiological environment and often investing more powder activated carbon.
2 Necessity of prior anaerobic hydrolysis of organic wastewater
In the continuous operation of the organic wastewater biochemical treatment device, a hydrolysis reactor has been successfully installed before the aerobic biochemical process, and its effects are as follows:
(1) Anaerobic biochemistry can liquefy organic suspensions, making the hydrolysis tanks function as a sinker for the precipitation of organic solids. (2) It can convert complex organic matter into simple organic matter and improve the efficiency of aerobic biological treatment. (3) Anaerobic digestion can digest the remaining activated sludge in the aerobic biochemical plant, and the amount of residual sludge itself is also small. Even if the sludge balance is not achieved, the activated sludge can be anaerobicly treated to achieve hygiene and harmlessness, and the amount of sludge treatment can be reduced, so that the sludge can be easily dehydrated. (4) The anaerobic biochemical process has no oxygen solution and diffusion problems, and can be adapted to the treatment of high-concentration organic wastewater. After anaerobic decomposition of wastewater, it is possible to reduce or not use diluted water before transferring to an aerobic biochemical plant. At the same time saving aeration power consumption. (5) The need for anaerobic microorganisms with nitrogen and phosphorus is much less than that for activated sludge. Obviously, the organic wastewater mentioned above has the benefit of hydrolytic acidification prior to aerobic biochemistry and is equally applicable to SBR technology. Due to the following three characteristics, the role will play better. (1) Since the excess sludge of the activated sludge SBR method is less than the general activated sludge method, the entire system can be greatly simplified by digesting the remaining activated sludge by the hydrolysis of the I pool.
(2) Since the hydrolysis tank is operated by the SBR method, anaerobic sludge with a long sludge age is easy to retain, and the hydrolysis efficiency will be improved.
(3) The residence time of anaerobic water SBR can be adjusted to optimize the technical and economical effects of the entire anaerobic hydrolysis-aerobic biochemical system.
3 Design of local conditions for hydrolysis pond
Due to capital and site constraints, when the activated sludge SBR system was changed to a hydrolysis-aerobic bio-chemical SBR system, the sludge concentration pool could only be changed to a hydrolysis tank according to local conditions. The advantages are as follows:
(1) There are a large number of anaerobic sludges evolved from the remaining activated sludge in the pool, with a long sludge age and quick start-up.
(2) There is aerobic SBR sludge sludge discharge pipe to facilitate the treatment of the remaining activated sludge.
(3) The pool is underground reinforced concrete structure, easy to keep warm.
(4) The pool has been partitioned into two pools of size and size. A submersible pump for circulation can be set in the pool and used as a dosing tank.
Using the above conditions, as long as the liquid distribution pipe is added to the bottom of the main tank where the original sludge shrunk, and the circulation pump constitutes a liquid system, circulation and stirring can be carried out, and the tank cover and take-out (after settling sludge) of the supernatant liquid can be performed. Suction pumps form a simple anaerobic hydrolysis tank.
The hydrolysis-aerobic biochemical treatment system is shown in Figure 2. Compared with the process before and after the transformation, the device and process are significantly simplified.
4 hydrolysis-aerobic biochemical SBR operation method
The cycle of anaerobic hydrolysis of SBR is the same as the aerobic biochemical SBR. It is also divided into five stages: water intake, reaction (continuous or intermittently circulating agitation), standing, drainage, and preparation. Specific operating methods and operating conditions are omitted.
5 After the transformation