Method for treating waste liquid of sweet potato fuel alcohol

Abstract

The invention belongs to the technical field of environmental protection, and particularly relates to a method for treating waste liquid of sweet potato fuel alcohol. The process flow of the method is as follows: sequential batch ASB (Anaerobic Sludge Bed) reaction -> two-stage SBBR (Sequential Batch Biofilm Reactor) aerobic reaction -> flocculation precipitation. In the anaerobic reaction, intermittent sequential batch water feeding is adopted, and after digestive fluid is settled on standing, water is discharged; in the aerobic reaction, a denitrifier agent is added; and in the flocculation precipitation, a high-efficiency composite flocculating agent formed by mixing polyferric sulfate and ferric trichloride heptahydrate is added. The method has the advantages of high anaerobic organic load, short hydraulic retention time, high organic matter removing rate and high methane yield, and the difficult problem that a high-efficiency anaerobic reactor is hard to run due to high inflow water SS (Suspended Solid) concentration; the removing rate of aerobic organic matters is high and the denitrification effect is good; and in flocculation precipitation, the removal rate to chromaticity and TP (Total Phosphorus) is more than 95%, the removal rate of COD (Chemical Oxygen Demand) is about 70%, and the finally discharged water reaches the primary standard of integrated sewage discharge standard GB8978-1996.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and in particular relates to a method for treating sweet potato fuel ethanol waste liquid. Background technique [0002] Sweet potato fuel ethanol waste liquid is the residue after distillation of fuel ethanol from the solid-liquid separation filtrate of sweet potato fermentation products. For every ton of fuel ethanol produced, about 10m 3 waste liquid. Due to the use of thick mash fermentation technology, the waste liquid contains high concentrations of organic matter and nitrogen and phosphorus nutrients, and direct discharge will cause serious environmental pollution. Table 1 shows the monitoring indicators of the filtered filtrate of a fuel ethanol pilot test fermentation base. [0003] Table 1 Main monitoring indicators of sweet potato fuel ethanol waste liquid [0004] [0005] It can be seen from Table 1 that a sweet potato fuel ethanol project with a scale of 100,0...

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Problems solved by technology

[0008] The purpose of the present invention is to aim at the serious pollution of sweet potato fuel ethanol waste liquid, the existing sweet potato ethanol waste liquid treatment method has long anaerobic hydraulic retention time, low organic load, and high-efficiency anaerobic reactor is sensitive to influent SS content, aerobic The indicators of the effluent (COD, BOD, SS, pH) can only meet the GB8978-88 secondary discharge standard, and the chromaticity, NH 3 -N and TP and other indicators cannot meet the GB8978-88 second-level emission standard, let alone the GB8978-1996 first-level emission standard, etc., to provide an economical, efficient, stable operation, sweet potato fuel ethanol that can meet the first-level emission standard Method of waste liquid treatment

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