中和水解酸化生物接触氧化混凝气浮吸附处理山梨酸生产废水

针对山梨酸生产废水中主要污染物的理化性质和山梨酸对微生物具有抑制作用的特点,首先进行石灰中和-沉淀处理,使部分污染物转为沉淀物得以去除,并将废水的pH值提高到7~8,减弱生化处理阶段山梨酸对微生物的抑制作用。在生化阶段,采用水解酸化-好氧工艺,利用厌气菌和乳酸菌分解废水中残留的山梨酸,同时兼性细菌(水解菌和产酸菌)可将废水中的大分子有机物分解为易生化的小分子有机物,BOD5与COD之比值从0.19提高到0.30,改善了废水的可生化性,为后续好氧处理创造条件,提高生化处理的整体效果。实际工程运行效果表明:中和-水解酸化-好氧-混凝气浮-吸附工艺可将废水的ρ(COD)从15 000 mg/L降至100 mg/L以下,主要污染指标均达到国家排放标准。

Treatment of sorbic acid wastewater by neutralization, hydrolytic acidification, bio-contact oxidation, flotation and adsorption process

Due to the physical and chemical characteristics of the main pollutants in sorbic acid wastewater and the microorganism-inhibiting features of sorbic acid,neutralization and sedimentation treatment with lime were adopted as the first procedure to remove part of the precipitated pollutants,raise pH to 7-8,and alleviate the inhibiting of microorganisms by sorbic acid during the biochemical treatment process.Hydrolytic acidification and oxidation methods were used in the biochemical treatment process.Anaerobic bacteria and lactobacillus were used to degrade the residual sorbic acid,and facultative bacteria(hydrolytic bacteria and acid-producing bacteria) were used to degrade the large molecular organisms into smaller molecular organisms that could be easily biodegraded.The BOD5 to COD ratio increased from 0.19 to 0.30,indicating an improvement in biodegradability.This was beneficial to further aerobic treatment and the improvement of integrated effects of biochemical treatment.The operation results showed that the COD concentration declined from 15 000 mg/L to 100 mg/L,and the main pollutant concentrations met the National Discharge Standard after the neutralization,hydrolytic acidification,bio-contact oxidation,flotation and adsorption process.