Abstract: A preparation method of an antibacterial deodorizing modified fiber for water purification is provided. Maleic anhydride is used to perform an addition reaction with sodium polysulfide to generate a disulfide antibacterial agent I, the disulfide antibacterial agent I continues to react with 2-amino-5-nitropyridine in an acetic acid solution under the catalysis of sodium acetate to obtain a compound II, then, the nitro in the compound II is reduced into amino by ferrous sulfate, meanwhile, anhydride is hydrolyzed into carboxylic acid in a faintly acid aqueous solution to obtain a compound III, and finally, under alkaline conditions, the amino in the compound III reacts with the cyan in a polyacrylonitrile fiber to obtain a modified polyacrylonitrile fiber. The prepared modified polyacrylonitrile fiber can remove various heavy metals in sewage and has good antibacterial and anti-mildew effects, thereby achieving the effects of water purification and deodorization.

Abstract: The present disclosure provides a sedimentation tank capable of automatically adjusting liquid level and flow, which comprises one or more sedimentation cells which are connected in sequence, a water inlet pipe is arranged on the left side of the leftmost sedimentation cell; the front end of the water inlet pipe is bent and the input port of it is close to the wall; the highest point of the connecting pipe is lower than the highest point of the grease discharge port of the corresponding sedimentation cell, when the liquid level in the sedimentation cell reaches the discharge level of the connecting pipe, the connecting pipe automatically adjusts the flow according to different discharge level so as to adjust the liquid level of the sedimentation cell, and the settled sewage is discharged out of the tank or discharged into the next-stage sedimentation cell until the last stage, and finally discharged.

Abstract: The present application relates to the field of enzyme engineering, especially relates to a pullulanase as well as preparation and use thereof. The pullulanase and coding gene thereof were obtained by random mutation by using the Error-prone PCR technique on the gene of wild-type pullulanase to obtain a mutant PLUM. The enzyme activity of the mutant PLUM was improved by 57.03% compared with the wild-type pullulanase PLUM.