秸秆-钢渣混合填料对低C/N比污水脱氮研究

Nitrogen removal of wastewater with low C/N ratio by straw and steel slag mixed fillers

为探讨作物秸秆和钢渣对低C/N比污水脱氮的影响,本研究分别以空白(CK)、小麦秸秆(W组)、水稻秸秆(R组)、小麦秸秆+钢渣(WF组)、水稻秸秆+钢渣(RF组)、钢渣(F)为填料,在厌氧循环系统中对C/N比为0.23~0.93的污水进行处理,探究6种不同的填料-系统对NO3-N的去除效果。结果表明:W组、R组、WF组和RF组的NO_(3)^(-)-N去除率分别为94.99%、86.70%、98.75%和94.70%;相比于WF组和RF组填料系统,纯秸秆填料系统(W组和R组)对污水中NO_(3)^(-)-N的去除速度更快,但在处理过程中的可溶性有机碳(DOC)浓度更高;WF组和RF组钢渣中含铁化合物的释放及转化会消耗有机质,因此其DOC浓度保持在较低水平,避免了因DOC浓度过高而引起的二次污染问题。综合考虑,小麦秸秆+钢渣混合填料在脱氮过程中能够在保持高效脱氮的同时避免出水二次污染问题,更适用于低C/N比污水的脱氮。

To investigate the impact of crop straw and steel slag on nitrogen removal from low carbon-to-nitrogen ratio(C/N)sewage,this study employed wheat straw(W group),rice straw(R group),wheat straw+steel slag(WF group),and rice straw+steel slag(RF group)as packing materials in an anaerobic circulation system for treating sewage.The effectiveness of these six different packing systems in removing nitrate-nitrogen(NO 3-N)was evaluated.The results demonstrated that the NO_(3)^(-)-N removal rates for the W,R,WF,and RF groups were 94.99%,86.70%,98.75%,and 94.70%respectively.Compared with the WF and RF groups which utilized mixed packings of straw and steel slag,the pure straw packing systems(W and R groups)exhibited higher rates of NO_(3)^(-)-N removal but resulted in elevated concentrations of dissolved organic carbon(DOC)during the treatment process.The presence of iron-containing compounds released from the steel slag in both WF and RF groups facilitated organic matter consumption,thereby maintaining a lower DOC concentration level throughout the treatment process to prevent potential secondary pollution caused by high DOC concentration.After comprehensive consideration,the utilization of a wheat straw+steel slag mixed filler could effectively prevent secondary pollution in the process of nitrogen removal while maintaining efficient nitrogen removal,making it more suitable for practical applications in low C/N ratio sewage treatment.