Bacteria distribution and dynamics in constructed wetlands based on modelling results
Bacteria distribution and dynamics in constructed wetlands based on modelling results
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DOI：
10.1016/j.scitotenv.2013.04.073
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发表时间：
2013-09-01
影响因子：
9.8
通讯作者：
Garcia, Joan
中科院分区：
文献类型：
--
作者：
Samso, Roger;Garcia, Joan
人工湿地中的细菌群落对污水中污染物的去除起着重要的作用，稳定的群落是影响其去除效果的关键因素。通过这项工作，我们的目标是找出人工湿地中细菌群落稳定所需的时间，并回答有关其丰度，空间分布及其在处理过程中的相对重要性的具体问题。为此，采用BIO_PORE数值模型，模拟了湿地内异养菌、自养硝化菌、发酵菌、乙酸营养型产甲烷菌、乙酸营养型硫酸盐还原菌和硫化物氧化菌等6种功能菌群在3年内的动态变化。使用了三个细菌稳定性指标：1）总生物量; B）流出物污染物浓度和c）香农多样性指数。结果表明，好氧细菌占主导地位的湿地，直到第80天的运行。从那一刻起，厌氧细菌占主导地位的湿地，直到研究期间结束。细菌稳定性在开始操作后400至700天之间达到。一旦湿地达到稳定，硫酸盐还原菌占所有细菌群的最高生物量（46%）。细菌稳定后得到的细菌群落的分布与现有的实验结果是一致的，并明确控制溶解氧（SO）浓度和H2S的毒性。稳定后，惰性固体的逐渐积累将活性细菌区的位置推向出口部分。(C)2013爱思唯尔有限公司版权所有。
Bacteria communities growing in constructed wetlands play a major role on the removal of pollutants from wastewater and the presence of a stable community is a critical factor affecting their performance. With this work we aimed at finding how long it takes for bacterial communities to stabilise in constructed wetlands and at answering specific questions regarding their abundance, spatial distribution and their relative importance on the treatment processes. To this end the numerical model BIO_PORE was used to simulate the dynamics of 6 functional bacteria groups (heterotrophic, autotrophic nitrifying, fermenting, acetotrophic methanogenic, acetotrophic sulphate reducing and sulphide oxidising bacteria) within a wetland for a period of 3 years. Three indicators of bacterial stabilisation were used: 1) total biomass; b) effluent pollutant concentrations and c) Shannon's diversity index. Results indicate that aerobic bacteria dominated the wetland until the 80th day of operation. Anaerobic bacteria dominated the wetland from that moment and until the end of the studied period. Bacteria stability was reached between 400 and 700 days after starting operation. Once the wetland reached stability, sulphate reducing bacteria accounted for the highest biomass of all bacterial groups (46%). The distribution of bacterial communities obtained after bacterial stability is consistent with available experimental results, and was clearly controlled by dissolved oxygen (SO) concentrations and H2S toxicity. After stability, the progressive accumulation of inert solids pushed the location of the active bacteria zone towards the outlet section. (C) 2013 Elsevier B.V. All rights reserved.