Sewage treatment facilities in the official put into use, the biochemical treatment devices are required for sludge inoculation, acclimation (commonly known as debugging). For the larger sewage treatment facilities try to shorten the commissioning time, so that the main body into operation as soon as possible, in the actual operation of the process has an important significance. Through the biochemical commissioning of several thousand tons of sewage treatment facilities on a daily basis, we found that during the process of biochemical commissioning, it is possible to complete the inoculation of biochemical facilities with bacteria after 7 to 10 days at normal temperature if the preparation is adequate. After 10 days, Domesticated sewage, 20d or so can enter the normal operation. This article will be divided into three aspects of biochemical commissioning work should be noted that the issue of a brief analysis. For convenience, the data listed in the text are based on a biochemical pool volume of 5000m3. A preparatory phase 1.1 material preparation ①sludge preparation For a million cubic meters of sewage treatment plant, the larger its biochemical pool, in order to ensure that the biochemical pool initial sludge concentration, need to prepare a large amount of raw sludge. In theory, the mass concentration of sludge in the biochemical pool after dosing is best controlled at about 2 500 mg / L. In actual operation, in order to save costs, the initial concentration of sludge during commissioning can be controlled at around 1 500mg / L, and the wastewater treatment plant with a treatment time of 1 × 104m3 for 12h on a daily basis is taken as an example. 80% of activated sludge about 40m3. Sludge species is best the same or similar activated sludge. In case of difficulties, other activated sludge can also be used. Sludge before use in order to ensure a certain degree of activity, the treatment of sludge to be sprayed moisturizing treatment, under the conditions of moisture in the sludge activity can be maintained at least 15d above. ② carbon source training send preparation The ideal carbon source during biochemical commissioning is manure and starch. In general, pre-test to join the main droppings, in the late to join the starch-based, take the cost of production, starch can be replaced by the ground Flour. Due to the fact that the excrement can not be stored in advance, it is necessary to determine with the relevant department in advance the quantity needed during the commissioning. Carbon source preparation during commissioning is generally estimated as follows. The amount of COD dosed daily to the biochemical pool is calculated according to the mass concentration of COD in the biochemical pool being between 200 and 300 mg / L. The mass conversion COD of the ground flour is about 1 t [COD] / t [flour]. COD conversion of dung is more difficult, according to experience, during the entire commissioning of 100 ~ 150 m3 of dung. The purpose of adding dung addition to carbon source, but also increase the introduction of biochemical pool bacteria. Ground flour can be prepared 10 ~ 15t. ③ phosphorus source, nitrogen source preparation The supplemental carbon source is generally Ca (Ca) 2 (H 2 PO 4) 2, while the nitrogen source is urea CO (NH 2) 2. Biochemical pool COD mass concentration of 300mg / L estimated BOD5 value is generally based on 100mg / L, the supplement by m (BOD5): m (N): m (P) = 100: 5: 1 conversion, the daily need to add starch 2000-3000kg, urea 100kg, 20000 calcium supplement, the quality ratio of starch: urea: calcium supplement = 20-30: 1: 2 supply. During the preparation of urea need to prepare 2 ~ 3t, calcium 5 ~ 6t. In addition, if conditions can be prepared 10 ~ 20kg powder anionic polyacrylamide (PAM). 1.2 material system and transportation equipment Due to the large amount of material needed during commissioning, together with the biochemical commissioning without sewage, the sewage flow in the pond is poor. To increase the inoculation speed, it is necessary to input the sludge and supplemental carbon source into each biochemical pool as evenly as possible. Therefore, for a certain size of sewage treatment facilities to set up materials and materials handling system, to reduce labor intensity and improve the efficiency of debugging is necessary. According to experience, material preparation pool should be located in the ground, pool equipped with air mixing device, the pool volume is generally 20 ~ 30m3. The pool is divided into two areas, a district for the system area, the district need to set up materials and primary garbage removal device; the second area for delivery, set the submersible pump or submerged pump, while the pump around to prevent the pump with the pump Clogged. Conveyor pipe should be used near the biochemical pool hose to adjust the feeding and feeding points as needed. In addition, the best material setting next to a fire hydrant or pipe for the preparation of sludge and other materials for water supply. 1.3 monitoring equipment preparation In line with the biochemical commissioning, COD (chromium method), dissolved oxygen, pH, bacteria and other indicators in the biochemical pool need to be monitored. General biochemical treatment debugging with the following monitoring equipment: COD tester, dissolved oxygen tester, pH tester, microscope. Second, the commissioning phase 2.1 Initial (3d) ①First, the biochemical pool into a certain amount of water and part of the sewage to be treated, and then pour the sludge into the material pool system. Generally the first dosing 20m3 sludge, while dosing dung and other culture materials, add water, stir and proportionally added to the biochemical pool. Dosing materials to feed the biochemical pool of COD concentration control 300mg / L prevail. And then add the proportion of calcium supplement (due to add dung without additional nitrogen source).
Trunnion mounted ball valves are designed for upstream sealing. The load generated by the line fluid on ball is absorbed by the trunnion bearings and is directly transmitted to the valve body, and the upstream seat driven by medium pressure drifts towards the ball to creater reliable sealing. The seat design has a built-in automatic cavity relief mechanism.
Trunnion Mounted Ball Valve, Trunnion Ball Valve Manufacturer, Cast Steel Ball Valve Supplier, Stainless Steel Ball Valve, Double Block & Bleed Valve Wenzhou Kolink Valve Co., Ltd. , https://www.kolinkvalves.com