芦苇床系统净化污水的机理

Mechanisms of sewage purification by reed bed system

人工模拟芦苇床系统净化污水的机理为：芦苇根际具有较高的氧化还原势，为好氧性微生物的活动创造了有利条件。芦苇床内根际微生物的数量与污染物去除率之间有明显的相关性。污水中的有机污染物是通过芦苇床内各种微生物的协同作用而去除；ＮＨ３－Ｎ主要是通过硝化作用和反硝化作用的连续反应而去除；总大肠菌群的去除一方面是由于原生动物的捕食作用和某些放线菌产生的拮抗作用，另一方面亦受营养、温度、ｐＨ值等因素的影响；ＳＳ和Ｏ－ＰＯ４－Ｐ的去除主要通过沉淀、过滤、吸附、固结等理化作用而实现。芦苇床内的优势细菌属为：假单胞菌属（Ｐｓｅｕｄｏｍｏｎａｓ），产碱杆菌属（Ａｌｃａｌｉｇｅｎｓ），黄杆菌属（Ｆｌａｖｏｂａｃｔｅｒｉｕｍ）。原生动物以肾形虫（Ｃｏｌｐｏｄａ）居多。

Mechanisms of sewage treatment by Reed Bed System was studied in an artificial imitative reed bed.The principal results are:(1) The ability of reed to supply its root system with oxygen from the aerial foliage and the resultant diffusion of a proportion of this oxygen into the surrounding soil to creat an aerobic rhizosphere is considered crucial to the process.(2)The correlation between microorganism quantities and removal efficiencies of pollutants in reed bed is significant. Organic materials are oxidized in a higher speed by the rhizophere microorganisms associated with reed and nitrogen compounds are believed to be eliminated by simultaneous nitrification and denitrification with the resultant release of gaseous nitrogen.SS and phosphorus are removed from sewage by physical and chemical reactions.Total coliforms are considered to be removed effectively through interactions with the bed microflora and unfavourable temperature conditions.(3)The predominant bacteria in reed bed are Pseudomonas.Alcaligens.Flavobacterium and the major protozoa is Colpoda in reed bed.