Treatment method for biodiesel waste water

Abstract

A treatment method for biodiesel waste water is carried out by the following steps: arranging self-clearing gratings at water pipe network end points under production equipment, and pumping waste water flowing across the gratings into a multi-stage oil separator; pumping the waste water in the water layer of the oil separator into an electrolytic tank; pumping the waste water from which oil is separated and removed through electrolysis into a micro-electrolysis reaction tank to carry out micro-electrolysis treatment; pumping the micro-electrolyzed waste water into a Fenton system to carry out reaction; feeding the waste water treated by multiple steps into a biochemical system; removing SS from discharged water by efficient shallow gas flotation micro-flocculation; sequentially filtering the waste water purified by micro-flocculation by a sand filter, active carbon and an ultra-filtration system; pumping various sludge produced in the waste water treatment process into a sludge concentration tank. The method has the advantages that oil is fully separated from the waste water, and no impurities are left; massive COD and PH are removed, the water feeding pressure of the biochemical system is reduced, waste water toxicity is reduced, biodegradability is improved, waste water color and smell are removed, and the quality of finally discharged clear water reaches domestic first-grade emission standards.

Description

technical field [0001] The invention relates to the field of waste water treatment, in particular to a waste water treatment method in the biodiesel production industry. Background technique [0002] In recent years, with the country's promotion of new energy, the domestic biodiesel industry has developed rapidly. Biodiesel refers to fatty acid methyl esters produced by the reaction of catering waste oil or various waste animal and vegetable oils with methanol. The product's molecular structure, density The calorific value and combustion performance are similar to those of petrochemical diesel. It can replace petrochemical diesel as fuel for internal combustion engines. It is a typical way to turn waste into treasure, so this new energy is called biodiesel. In the production process of biodiesel, raw material pretreatment process, esterification process, and distillation process will generate wastewater, which is collected with workshop cleaning wastewater, boiler desulfuriz...

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Problems solved by technology

[0003] At present, biodiesel wastewater treatment methods mainly include chemical-physical methods and biological methods. The chemical-physical methods mainly use multi-effect evaporator fractional distillation. This method is feasible for enterprises with small sewage volumes. The disadvantages are large investment and high operating costs. With the expansion of production and the increase of wastewater volume, this method is not feasible from the perspective of energy saving and emission reduction; biological method refers to the use of strong oxidative degradation function of microorganisms under appropriate temperature, pH, nutrients and oxygen conditions, Method for removing organic pollutants from wastewater

Because biodiesel wastewater contains a large amount of oil and salt, and the concentration is high, and the quality and quantity of wastewater are fluctuating irregularly, the conventional pretreatment and adjustment tanks cannot meet the water requirements of the biochemical system, so the biological method is mostly in an unfavorable position. During commissioning, there is no effective method to treat the wastewater generated in the biodiesel production process

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