Method for producing microbial flocculant by utilizing culture wastewater and residual activated sludge

Abstract

The invention discloses a method for producing a microbial flocculant by utilizing culture waste water and residual activated sludge. The method comprises the steps of: first implanting bacterial strains into a seed culture medium to culture a seed liquid; second, adding cane sugar (as a supplemented carbon source) and phosphate (for adjusting pH) in the culture wastewater to prepare a culture wastewater fermentation medium, and mixing the culture wastewater with pretreated residual activated sludge in a volume ratio of 1:5-1:8 to prepare a culture wastewater-residual activated sludge fermentation medium; and at last, inoculating a 1-2% seed liquid to the fermentation medium, and using a two-step fermentation technology for fermentation production of flocculant, thereby producing the microbial flocculant. The method of the invention utilizes culture wastewater rich in N, P and K and residual activated sludge rich in organic matters to produce microbial flocculant, so as to greatly reduce the production cost and realize comprehensive utilization of waste. The production method is simple and easy, and the produced microbial flocculant has high flocculation performance.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment and disposal, and specifically relates to a method for producing microbial flocculants using aquaculture wastewater and residual activated sludge by adopting a two-step fermentation process. The microbial flocculant production bacteria selected in the invention is Rhodococcus erythroflates. Background technique [0002] For a long time, inorganic flocculants represented by iron salts, aluminum salts and their polymers and organic polymer flocculants represented by polyacrylamide and their derivatives have been successfully used in industrial wastewater treatment, drinking water purification, sewage Mud dehydration, food processing and fermentation industries. Although inorganic flocculants and organic flocculants have good flocculation effect and low cost, they cause non-negligible harm and pollution to human body and environment during use. Studies have shown that aluminum salts can...

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Problems solved by technology

In recent years, studies on the production of flocculants using cheap medium have been reported successively. For example, Liu Hui et al. have studied the use of soy sauce wastewater by Penicillium to produce microbial flocculants. The optimal dosage of this bioflocculant for treating kaolin suspension is 10-15ml / L; Zhou Xu et al. adopt Pseudomonas CX-4 to produce flocculant by using fishmeal processing wastewater, which has the defect of low flocculant production efficiency, and the flocculant output is only 0.612g / L; Chinese patent CN101225405A discloses Krebs A method for bacteria to produce microbial flocculants using starch and compound nitrogen sources. The microbial flocculants can be used in combination with metal ions to reduce the amount of flocculants by 2 to 4 times, but the following defects exist in the production process: It is difficult to implement the preparation technology of Burgeria seed solution; the compounded calcium ion-containing solution and aluminum ion-containing solution are used in large quantities, generally 2-4ml 15-20g / L calcium-ion-containing solution and 2-4ml 2-4g / L Aluminum ion-containing solution; the yield of bioflocculant is low

Chinese patent CN101948183A discloses a method in which Aspergillus sojae utilizes beer wastewater, molasses wastewater, and monosodium glutamate wastewater to produce microbial flocculants. 2+ 、Ni 2+ There is a certain removal effect, but there are the following defects in the production process: the carbon source consumption of the seed medium is relatively large (30g / L); the replacement medium needs to add a large amount of carbon source (10g / L); the flocculation rate is only It can reach 73.9%; the output of flocculant is low, only 1.5-2.1g / L

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