贫营养条件下生物除铁除锰滤池生态稳定性研究

Ecological Stability on Biological Removal of Iron and Manganese Filter Under Poor Nutritional Conditions

采用将反冲洗排水回流至生物除铁除锰滤池的方式补给滤层细菌数量、回流可利用营养物质.试验从滤池整体除铁除锰效果、微生态特性及优势细菌数量分布3方面考察滤池的生态稳定性.结果表明,在高滤速(10～13.9 m/h)、高锰浓度(3.5～4.5 mg/L)条件下生物滤池对铁锰的去除率达98.9%以上,滤池具有较强的抗负荷冲击能力.铁、锰氧化细菌为滤层的优势菌群,数量达106数量级,它们既附着在滤料表面上(4.3×106个/mL)形成致密的生物膜,又存在于滤料间(6.5×106个/mL)形成以细菌为主体的悬浮絮体,此絮体对铁锰的彻底去除至关重要.经过近5年的连续运行,在不投加营养盐的前提下生物滤池实现了稳定运行,保持了高除铁除锰效率.

To supply necessary bacteria and available nutrients,a method of returning backwashing wastewater to the bio-filter for removal of iron and manganese was used.The ecological stability of bio-filter was investigated from 3 aspects： iron and manganese removal efficiency,micro-ecological characteristics and the quantity distribution of dominant bacteria.The results indicated that,the bio-filter held strong anti-shock loading capability,when the system was operated at high filtration rate（10-13.9 m/h） and high manganese concentration（3.5-4.5 mg/L）,a removal rate more than 98.9% of iron and manganese was achieved.Iron and manganese oxidizing bacteria are the dominant microflora in biological filtering layer,they not only adhere on filter sand materials（4.3×10^6 MPN/mL）to form compact biofilm,but also exist among filter materials void（6.5×10^6 MPN/mL） to form suspended flocs,which is very important to complete removal of iron and manganese.In the past 5 years,the bio-filter realized a continuo.us and stable operation and kept a high removal efficiency of iron and manganese without adding any nutrients.