Method for treating garlic processing wastewater

Abstract

The invention relates to a method for treating garlic processing wastewater, and belongs to the technical field of wastewater treatment. The method for treating garlic processing wastewater comprisesthe following steps: (1) preparing a fine grid and a grit chamber; (2) adding vegetable oil into the garlic processing wastewater, and performing stirring, full mixing, and standing for layering to obtain an oil phase and wastewater; (3) separating and purifying the oil phase to obtain allicin; (4) performing air floatation; (5) performing micro-electrolysis; (6) after the wastewater is subjectedto the micro-electrolysis, adding sodium hydroxide to adjust the pH value to 7.8-8.6; (7) introducing the wastewater into a first sedimentation tank for sedimentation; (8) performing biological pretreatment; (9) performing aerobic treatment; (10) after the aerobic reaction, feeding the wastewater into a second sedimentation tank for sedimentation; (11) performing treatment in a V-shaped filter tank; and (12) performing treatment in an ultraviolet disinfection tank. According to the method, during biological pretreatment, the impact of condition changes such as COD and organic sulfide concentration and water quantity in the garlic processing wastewater on the degradation effect can be greatly reduced through a complex microbial inoculant, and the stability of the pretreatment effect is guaranteed.

Description

technical field [0001] The invention relates to a method for treating garlic processing wastewater, belonging to the technical field of wastewater treatment. Background technique [0002] my country is the largest garlic producer in the world. Not only does the production and export volume of fresh garlic rank first in the world, but the garlic processing industry is also booming. There are two main types of processed products: garlic flakes and garlic oil. Among them, the annual processing volume of dehydrated garlic flakes in my country is about 300,000 tons, and each ton of dehydrated garlic flakes needs to consume 30-40 tons of water. It can be seen that garlic production and processing enterprises will generate a large amount of waste water every year and need to be discharged. [0003] Garlic processing wastewater contains a large amount of organic pollutants, suspended solids, ammonia nitrogen and other substances, including the gum juice from garlic cloves, namely ga...

AI Technical Summary

Problems solved by technology

If it is directly discharged into the water body without treatment, it will consume a large amount of dissolved oxygen in the water, resulting in the lack of oxygen in the water body and the death of aquatic organisms.

Garlic processing wastewater also has a strong antibacterial effect. Garlic processing wastewater contains allicin, and the sulfide in allicin can penetrate the cell membrane of the pathogen into the cytoplasm, oxidize the enzyme containing sulfhydryl to disulfide bond, and thus inhibit cell division. , destroy the normal metabolism of microorganisms, and also cause a large number of deaths of fish, shrimps and water microorganisms, resulting in serious environmental pollution

If it is not treated in time, the suspended solids in the wastewater will sink to the bottom of the water, deteriorating the water quality. It contains a strong pungent smell and acrid taste, and it will produce a strong stench if left for a long time, which will have a huge impact on the factory area and nearby residents.

[0004] Garlic processing wastewater is generally treated by traditional biochemical methods, but there are inherent disadvantages: 1. Garlic processing wastewater is a very special kind of wastewater, in which allicin is a broad-spectrum fungicide, and it is treated by ordinary activated sludge aeration method , allicin has a strong inhibitory effect on active bacteria, reduces sludge activity, and the degradation ability of COD in water is very poor

2. The COD of garlic processing wastewater is about 20000mg / L, which is much higher than the tolerance of activated sludge (<3000mg / L). The raw wastewater can be used after being diluted 10-20 times, and each ton of garlic slices consumes about 20-40 cubic meters of tap water, resulting in a serious waste of water resources.