1, uneven mixing: oxygen in wastewater can't contact with organisms, which will cause dissolved oxygen in wastewater to exceed the standard.
2. The sewage flow is too small: when the sewage flow is too small, the oxygen supply of organisms will be greater than the demand, which will lead to the increase of dissolved oxygen concentration in the biochemical pool.
Materials: Polygonum Multiflori Radix, Adenophora adenophora, Coicis Semen each 1 5g, Polygonatum odoratum 20g, pig heart and pig lung each1pair, monosodium glutamat