钨酸铅光催化降解糖蜜酒精废水的研究

Degradation of Molasses Fermentation Wastewater by PbWO_4 Photocatalyst

糖蜜酒精废水是一种难降解的有机废水,主要成分为焦糖等色素类物质。利用沉淀法制备了PbWO4光催化剂,将其应用于光催化降解糖蜜酒精废水降解反应中,考察了催化剂用量,空气流量,溶液pH值,助氧化剂及光照强度对糖蜜酒精废水脱色率的影响。研究表明,在紫外光辐照下,PbWO4能有效地对糖蜜酒精废水进行光催化作用,过程为一级动力学反应。对于经30倍稀释的糖蜜酒精废水,添加4.0g·L-1的PbWO4光催化剂,通入126L·h-1的空气,不改变废水的pH值及不添加助氧化剂H2O2的条件下,在300W高压汞灯照射下反应120min,PbWO4光催化降解糖蜜酒精废水的脱色率为90.2%,COD去除率为78.6%,得到了较好的降解。

Molasses fermentation wastewater is a kind of deep brown, highly acidic, difficult degraded and condensable organic wastewater produced from sugar industry. The main colorful waste component of this wastewater is pigmental substance, such as caramel, and the like. The PbWO4 photocatalyst was prepared by precipitation method and was used to photocatalytic degradation of the molasses fermentation wastewater. The effects of PbWO4 used amount, air flow rate, pH value of the wastewater, the use of co-oxidant and the power of illumination on the wastewater degradation were studied. The results show that the molasses fermentation wastewater is degraded effectively by ultraviolet irradation in the present of PbWO4 as photocatalyst, and the process of PbWO4 photocatalyzed degradation of molasses fermentation wastewater is a first-order kinetic reaction. Under the initial pH value of the wastewater and without adding H2O2 co-oxidant, after irradiation for 120 min by a 300 W high-pressure mercury lamp with the PbWO4 amount of 4.0 g·L^-1 as photocatalyst and the air flow rate of 126 L·h^-1, the decolorization ratio of the 30 times diluted molasses fermentation wastewater is 90.2%; At the same time, the COD remove ratio is 78.6%. It shows that the molasses fermentation wastewater can be degraded efficiently by PbWO4 photocatalyst.