While the sand sedimentation tank in the sewage treatment plant investment, occupies a small proportion, but its role can not be ignored. If the sand sedimentation tank is canceled, a large number of sand particles will enter the subsequent treatment units, bringing many hidden dangers to the normal operation of the sewage plant:
①Sand particles into the primary sedimentation tank will accelerate the wear and tear of the sludge scraper, shortening the service life.
②The deposition of sand in the sludge discharge pipeline can easily lead to clogging of the pipeline, into the sludge pump will intensify the wear of the impeller.
③ For the treatment process without primary sedimentation tank (such as oxidation ditch, CASS, etc.) or the actual operation of the primary sedimentation tank due to the low water load beyond the operation of the process, a large number of sand particles will be directly into the biochemical tank deposition, resulting in the reduction of the effective volume of the biochemical tank, and also adversely affects the aerator.
4 sand particles into the sludge digester, will reduce the effective volume, shorten the cleaning cycle.
⑤The increase of sand content in sludge will greatly affect the operation of sludge dewatering equipment. Sand particles into the belt dewatering machine will aggravate the wear and tear of the filter cloth, shorten the replacement cycle, and at the same time will affect the flocculation effect and reduce the sludge cake rate. In recent years, decanter centrifuge in the city sewage treatment plant in the application of an increasingly wide range, due to the use of high-speed centrifugal separation of this equipment, the sand will greatly exacerbate the wear and tear of the rotor, screw and other places.