蒸发浓缩预处理黄姜皂素水解废液

针对黄姜皂素水解废液有机物浓度高、酸度高、可生化性差等特点，采用常压蒸发浓缩法预处理黄姜皂素水解废液，研究了初始pH值和浓缩倍数对废液主要污染物蒸发浓缩效果的影响。结果表明：初始pH值对蒸出液COD、氨氮、VFA浓度变化影响较大。pH-1、1 742 mg·L-1快速降低到980 mg·L-1、82.9 mg·L-1；氨氮浓度在25 mg·L-1处波动；pH>7时，COD浓度在1 000 mg·L-1处波动，乙酸由82.9 mg·L-1缓慢降低到6.4 mg·L-1，氨氮浓度由26.2 mg·L-1快速升高到207 mg·L-1。浓缩倍数对蒸出液污染物浓度影响也很大。浓缩2~10倍，COD、氨氮、乙酸浓度分别由980、26.2、82.9 mg·L-1升高到3 372、141、2 250 mg·L-1，对应占其污染物总量的百分比由0.66%、1.91%、1.46%升高到4.08%、18.5%、71.5%。考虑工艺设备耐腐蚀性、蒸发能耗、耗时和处理效果等因素，选择初始pH=7、浓缩5~7倍比较适宜。蒸出液经过适当处理可做工艺回用水，达到废水处理资源化、减量化的目的。

Pretreatment of yam diosgenin hydrolytic wastewater by evaporation concentration process

An evaporation concentration process was applied to pretreat hydrolytic wastewater containing yam diosgenin with a high concentration of organic matter, high acidity, and poor biodegradability. The removal effects of the main pollutants of wastewater resulting from variation of the initial pH value, and the concentration multiples were investigated. Results showed that the initial pH value of the wastewater had great impact on the concentration of COD, NH4+-N, and VFA of the evaporated liquor. The concentration of COD and acetic acid decreased rapidly from 4 045 and 1 742 mg·L-1, to 980 and 82.9 mg·L-1, respectively. The ammonia concentration fluctuated around 25 mg·L-1, when the initial pH value was 7, it appeared that the concentration of COD fluctuated around 1 000 mg·L-1. The ammonia concentration rose from 26.2 to 207 mg·L-1 rapidly, and that the VFA concentration decreased slowly from 82.9 to 6.4 mg·L-1. The concentration multiple was another factor with great impact on the concentration of COD, NH4+-N, and VFA of the evaporated liquor. While the concentration multiple was from 2 to 7,the concentration of COD, NH4+-N, and acetic acid rose from 980, 26.2, and 82.9 mg·L-1, to 3 372, 141, and 2 250 mg·L-1, respectively. The percentage of the total also rose respectively from 0.66%, 1.91%, and 1.46%, to 4.08%, 18.5%, and 71.5%. In terms of the factors including the corrosion resistance of the equipment, energy consumption, time consumed, and treatment effects, the conditions with initial pH 7 and the concentration multiple ranging from 5 to 7, could be recommended in the pretreatment process. The evaporated liquid could be reused as an industrial water supplement after proper treatment, for the purpose of wastewater reclamation and reduction.