水力负荷对生物沉淀池污染物净化性能的影响特性

本研究将生物转盘和平流式沉淀池设计理念相结合,开发出对水中致浊物质、有机组分、氨氮和总磷具有同步去除性能的一体式生物净化-沉淀池,考察了进水水力负荷对其污染物净化性能的影响规律.结果表明,在特定转盘转速和水质条件下,浊度、有机组分和氨氮的平均去除率随水力负荷的增大均呈先相对稳定后下降趋势,浊度和有机组分与氨氮平均去除率分别在0.036 g·(m~2·d)~(-1)与0.064 g·(m~2·d)~(-1)时达到最大.与浊度、有机组分和氨氮不同,水力负荷对总磷的去除效果影响较大,进水水力负荷在0.064 m~3·(m~2·d)~(-1)时,总磷平均去除率最差,适当减小或增大水力负荷,均有助于除磷过程的进行.进一步研究发现,硝化和除磷过程对水相中的有限碳源及溶解氧存在竞争关系.沿水流方向,盘片表面的微生物具有良好的种群配合和沿程分布特点,保证了在不利水力负荷条件下,工艺仍具有一定的去污效果,在微污染水体的强化净化处理中具有一定的应用前景.

Effects of Hydraulic Loading Rate on the Removal of Pollutants from an Integrated Biological Settling Tank

Based on the designing concepts of rotating biological disk and settling tank, a hybrid biological purification and settling tank was developed to achieve simultaneous removal of turbidity causing materials, organic matters, NH₄⁺-N, and TP. Experimental results showed that under certain rotary speed and water quality conditions, the removal rates of both turbidity and organic matters and NH₄⁺-N were relatively stable first and then started to decrease with the increase of hydraulic loading rate. The highest value was achieved at 0.036 g·(m²·d)^-1 and 0.064 g·(m²·d)^-1 respectively. Compared with turbidity and TOC and NH₄⁺-N, the removal rate of TP was greatly influenced by hydraulic loading rate. The average TP removal was the worst at 0.064 g·(m²·d)^-1. Appropriately decreasing or increasing the hydraulic load was helpful to the phosphorus removal process. Further study showed that nitrification and dephosphorization processes competed for the limited carbon source and DO in the water phase. Along the flow direction, the surface of the disc populations of microorganisms with good coordination and distribution along the characteristics ensured that the process still had certain decontamination effect under the condition of unfavorable hydraulic load, which indicated that the biological settling tank had a capacity in resisting organic loading rate shock and could be used in enhancing pollutant removal in treating micro-polluted water.