沉降法处理紫胶洗色废水的工艺研究

Research on the sedimentation method for the treatment of lac washing wastewater

采用单因素优化试验和响应曲面优化试验对紫胶洗色废水的沉降法处理工艺进行了优化,筛选出最佳沉降剂和最佳处理工艺条件。结果表明,CaO为最佳沉降剂。最佳处理工艺条件为:CaO投加量5.7g/L、pH=7、搅拌速率270r/min、反应温度50℃、反应时间30min。经最佳处理工艺处理后,悬浮物由211.8mg/L降至7.3mg/L,COD由4 019mg/L降至853mg/L,BOD5由3 800mg/L降至670mg/L,总有机碳(TOC)由4 392mg/L降至680mg/L,紫胶红色素由16.95mg/L降至0.25mg/L,说明绝大部分有机物发生了沉降,特别是紫胶洗色废水中相对含量较高的肉豆蔻油酸、肉豆蔻酸、棕榈油酸、棕榈酸、油酸、香叶基异戊酸6种有机酸得到了很大程度的去除。

Single factor optimization experiment and response surface optimizatioin experiment were used to select the best sedimentation agent and process. Results showed that CaO was the best sedimentation agent. The optimum process conditions were as fotlows：CaO dosage of 5.7 g/L, pH= 7, stirring rate of 270 r/min, reaction temperature of 50 ℃ and reaction time of 30 min. After the optimum CaO sedimentation treatment,suspended solid decreased to 7.3 mg/L from 211.8 mg/L,COD decreased to 853 mg/L from 4 019 mg/L,BOD5 decreased to 670 mg/L from 3 800 mg/L,total organic carbon （TOC） decreased to 680 mg/L from 4 392 mg/L,and haematochrome decreased to 0.25 mg/L from 16.95 mg/L. Therefore, most organic pollutants could be sedimented under the optimum process conditions, especially 6 organic acids of myristoleic acid, myristic acid, palmitoleic acid, palmitic acid, oleic acid and geranyl isovaleric acid.