摘要
研究了太湖不同类型(草型、藻型)沉积物的物理化学特征,也为研究磷在湖泊中的化学循环提供一些相关数据。首先分析了草藻型沉积物原有的物理化学特征。草藻型沉积物颗粒组成均以小于0.01 mm的粉砂和黏粒为主,占总量的49.5%～83.6%。藻型沉积物粒径组成中,小于0.002 mm的黏粒所占比例为30.04%～36.75%,明显高于草型沉积物(16.71%)。草型沉积物中烧失量(LOI),易氧化有机物(ROOM),总氮(TN)、总磷(TP)的含量都高于藻型沉积物含量。用乙酸钠作为碳源在间歇式小型反应装置(SBR)中对采自太湖藻型(1号点)和草型(24号点)沉积物进行实验。SBR反应装置的进水COD/P=20,运行周期24 h。SBR反应装置水力停留时间为48 h,固体停留时间约为20 d。经过50多天的实验,草藻型沉积物在富集驯化之后,都表现出厌氧释磷好氧吸磷的特征,表明太湖沉积物中存在聚磷菌。实验数据表明,藻型区沉积物更容易利用小分子有机质,其有机质(COD)去除率比草型区要高出6.9%。藻型区沉积物更易吸磷,而草型区沉积物更易富集聚磷菌。实验支持了微生物在沉积物中磷迁移转化中起着重要作用这一理论。
The physical and chemical properties of grass/algae type sediments in Lake Taihu, as well as the effect on polyphosphate accumulation were investigated. Silt and clay （less than 0.01 mm in diameter） is the majority particles of grass and algae type sediment, account for 49.5%-83.6%. The percentage of particles （less than 0.002 mm in diameter） in algae type sediments is 30.04%-36.75%, which is higher than that of grass type zone sediments （16.71%）. However, the content of loss on ignition （LOI）, readily oxidizable organic matter （ROOM）, total nitrogen （TN） and total phosphorus （TP） of algae type sediment are lower than that of grass type sediment in Lake Taihu. The sediment samples were collected from the two type zones and microorganism in these sediments were enriched by adding sodium acetate as carbon source in laboratory-scale sequencing batch reactors （SBRs）. The SBRs parameters were set： COD/P ratio in the feeding was 20：1.The cycle time was 24 h, the hydraulic retention time was 48 h, and the solids retention time was controlled at approximately 20 days. After more than 50 days, the orthophosphate concentration in both reactors increased at the anaerobic phase and decreased at the aerobic phase significantly, which confirmed that polyphosphate accumulating microorganism （PAOs） were existed in sediments of Lake Taihu. Our experimental data also showed that the low-molecular-weight organics are more easily absorbed by sediment in reactor AC1 （algae type zone sediments） than in reactor AC24 （grass type zone sediments）, corresponding to the removal of COD in reactor AC 1 was higher 6.9% than that of reactor AC24. Phosphorus was readily absorbed by algae type zone sediments, while PAOs were enriched in the grass type zone sediments. These results suggested that the bacteria took an important role in the transfer and transformation of phosphorus element in the sediments.
出处
《生态环境学报》
CSCD
北大核心
2012年第11期1859-1864,共6页
Ecology and Environmental Sciences
基金
国家重点基础研究发展计划(973计划)项目(2008CB418005)
金肯学院科研项目(JK2009001)
关键词
磷
序批式反应器(SBR)
沉积物
藻型区
草型区
太湖
phosphorus
sequencing batch reactors （SBRs）
sediments
algae type zone
grass type zone
Lake Taihu
