生物慢滤系统处理微污染水体的试验研究:两种滤料的对比

Experimental Study on Bio-slow Filtration System for TreatingMicro-polluted Water:A Comparison of Two Fillers

滤料的特性是决定生物慢滤系统对各类污染物去除效果的主要因素之一,然而国内外在不同滤料的生物慢滤系统净化效能比较和微生物机制方面的研究十分有限。本研究选用石英砂和活性炭作为生物慢滤系统的滤料,比较了它们在污染物去除和微生物群落方面的异同,并在滤料堵塞时开展了反冲洗实验。结果表明,两柱均需要26 d完成挂膜。挂膜完成后,活性炭柱对浊度、CODMn和氨氮的去除率分别为92.18%、65.53%和99.37%,而石英砂柱的去除率分别为91.89%、42.91%和98.87%,活性炭柱的去除率优于石英砂柱。在挂膜期间,石英砂柱和活性炭柱都出现了亚硝酸盐氮和硝酸盐氮的积累现象。石英砂柱主要的优势菌群为A0839和Rhodobacter,而活性炭柱主要的优势菌群为Ramlibacter、Pseudomonas和Leptospirillum,从微生物群落的角度解释了活性炭柱对有机物和总氮的去除效果优于石英砂柱。活性炭滤料的穿透深度大于石英砂滤料,石英砂柱的滤料主要是前40 cm发生堵塞,而活性炭柱的滤料是前60 cm发生堵塞。在滤料膨胀系数为30%时,石英砂柱和活性炭柱的反冲洗强度分别为6.83 L·m^(-2)·s^(-1)、3.16 L·m^(-2)·s^(-1),活性炭柱的反冲洗水量比石英砂柱少了53.7%。本研究为农村地区慢滤系统滤料的选择提供了技术依据,为滤料的堵塞问题提供了经济可行的解决方案,为该技术在农村供水技术中的应用提供了技术支持。

The characteristics of fillers determine the removal efficiency of various pollutants in bio-slow filtration systems.However,research on the comparison of purification performance and microbial community differences in bio-slow filtration systems using different fillers is limited both domestically and internationally.In this study,quartz sand and activated carbon were chosen as fillers in the bio-slow filtration system,and their differences in pollutant removal and microbial community were compared.Backwashing experiments were conducted using a self-designed bio-slow filtration device when the fillers became clogged.The results showed that both columns required 26 days for biofilm formation.After biofilm formation,the average removal rates of turbidity,COD Mn,and ammonia nitrogen by the activated carbon column were 92.18%,65.53%,and 99.37%,respectively,while those by the quartz sand column were 91.89%,42.91%,and 98.87%,respectively.The activated carbon column showed better removal efficiency compared to the quartz sand column.During biofilm formation,both the quartz sand and activated carbon columns exhibited accumulation of nitrite nitrogen and nitrate nitrogen.The dominant bacterial groups in the quartz sand column were A0839 and Rhodobacter,while in the activated carbon column,the dominant bacterial groups were Ramlibacter,Pseudomonas,and Leptospirillum.This microbial community analysis provided an explanation for the superior removal efficiency of organic matter and total nitrogen in the activated carbon column compared to the quartz sand column.The penetration depth of activated carbon filter media is greater than that of quartz sand filter media.In the quartz sand column,clogging mainly occurs in the first 40 cm of the filler,while in the activated carbon column,clogging occurs in the first 60 cm of the filler.At a filter media expansion coefficient of 30%,the backwash intensities for the quartz sand column and the activated carbon column were 6.83 L·m^(-2)·s^(-1)and 3.16 L·m^(-2)·s^(-1),respectively.The activated carbon column required 53.7%less backwash water compared to the quartz sand column.This study provides technical basis for selecting filter media in rural slow filtration systems and offers economically viable solutions for addressing clogging issues.It also provides technical support for the application of this technology in rural water supply,benefiting rural communities.