Method for treating wastewater produced during extraction of saponin from dioscorea zingiberensis

Abstract

The invention discloses a method for treating wastewater produced during extraction of saponin from dioscorea zingiberensis. The method comprises steps as follows: (1), pretreatment: H<+> in the wastewater is sequentially neutralized with limestone and lime milk, and colloids, suspended solids and sulfate are removed; (2) two-stage anaerobic treatment: at the first stage of anaerobic treatment, the pretreated wastewater is subjected to hydrolytic acidification through hydrolytic acid-producing bacteria, macromolecular organic compounds are decomposed to be micromolecular organic compounds, and insoluble organic matters are hydrolyzed to form soluble organic matters; at the second stage of anaerobic treatment, an acidized product is further decomposed through methanogenic bacteria to generate methane, CO2 and H2O; (3) aerobiotic biochemical treatment: organic pollutants in anaerobic effluent are further decomposed under the action of activated sludge formed through air and aerobic microorganisms; (4) advanced treatment: aerobic effluent is treated under the synergistic effect of ozone and activated carbon. Treatment process units with different functions are reasonably combined and are successfully applied to treatment of produced wastewater dioscorea zingiberensis saponin.

Description

technical field [0001] The invention relates to a method for treating waste water produced by extracting saponin from turmeric, belonging to the field of water treatment. Background technique [0002] Saponin is a hormone widely present in animals and plants, and it is an important raw material for synthesizing contraceptives and steroid hormone drugs, while turmeric is a natural basic plant material for extracting saponin. The turmeric planting and processing industry is mainly concentrated in impoverished mountainous areas such as northwestern Hubei and southern Shaanxi. This area is the source of the Han River and the core water source area of ​​the South-to-North Water Diversion Project in my country. The water pollution problem in the processing of turmeric has become a constraint to the protection and economics of the water source area of ​​the South-to-North Water Diversion Project. The sustainable development of society is a major problem that needs to be solved urgen...

AI Technical Summary

Problems solved by technology

Therefore, aerobic biochemical treatment cannot be directly used. Simply using physical and chemical treatment not only has high treatment costs, but also cannot meet the discharge standards. Therefore, anaerobic biochemical treatment must be used.

However, under anaerobic conditions, sulfate-reducing bacteria convert SO 4 2- converted to H 2 S, H 2 S has strong biological inhibition and toxicity, when S 2- When the content is 60mg / L, the activity of methanogens will be reduced by 50%; and the allowable concentration of aerobic microbial treatment for sulfide transport is 40mg / L, S 2- Too high not only consumes a lot of oxygen, but also easily causes aerobic activated sludge bulking and sludge poisoning

In order to eliminate the impact of sulfide, one is to reduce SO from the source 4 2- Concentration, the commonly used method is the lime precipitation method, but because CaSO 4 Slightly soluble, need to add excessive lime, so it will bring problems such as scaling and blockage; the second is to use the second-stage anaerobic process to convert the H produced in the first-stage anaerobic process 2 S is separated from the system in time, and the methods of air stripping or chemical precipitation are commonly used. The chemical precipitation method has high efficiency but produces a large amount of sludge and high operating costs. certain inhibitory effect