Quantitative evaluation of treatment processes and mechanisms of organic matter, phosphorus, and nitrogen removal in a multi-soil-layering system
Quantitative evaluation of treatment processes and mechanisms of organic matter, phosphorus, and nitrogen removal in a multi-soil-layering system
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DOI：
10.1080/00380768.2011.590944
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发表时间：
2011-06
影响因子：
2
通讯作者：
Kuniaki Sato;N. Iwashima;T. Wakatsuki;T. Masunaga
中科院分区：
文献类型：
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作者：
Kuniaki Sato;N. Iwashima;T. Wakatsuki;T. Masunaga
多层土壤（MSL）系统的水处理性能主要通过测量废水和处理水的质量差异来评估。系统内水质的变化尚未与水的运动一起进行评估。因此，在本研究中，使用实验室规模的MSL系统对MSL系统内部的处理过程进行定量评估，该系统设置在10厘米（深）×50厘米（宽）×23-73厘米（高）的丙烯酸盒子中，其中封闭了与渗透性沸石层交替的“土壤混合物块”。建造了由一到六个土壤混合物层（SML）组成的六个MSL系统，并在每个系统的底部分别收集来自SML和SML之间的渗透层（PLb）的处理水。为了确定系统内部的处理工艺，将平均浓度为生物需氧量（BOD）28.1 mg L−1、化学需氧量（COD）65.7 mg L−1、总氮9.8 mg L−1、总磷1.0 mg L−1的废水以1000 L m−2 day−1的水力负荷引入系统。 SML 中的 BOD 和 COD 浓度均低于 PLb 中的浓度。随着 SML 中的流速降低和 PLb 中的流速增加，每个系统中 PLb 中的浓度增加。虽然在三层以上的系统中，BOD的去除率总是超过80%，但要达到与BOD相同的程度，需要六层。由于土壤和混合铁颗粒对磷的吸附，SML 中的磷浓度也低于 PLb 中的磷浓度。因此，SML 中的流量对除磷效率有很大影响。在本研究中，铵吸附和硝化作用几乎完成到MSL系统的第三层。然而，由于反硝化效率低，第四层以下的氮去除效果并不明显。
The water treatment performance of multi-soil-layering (MSL) systems has been mainly evaluated by measuring differences in the quality of wastewater and treated water. Changes in water quality inside the system have not been assessed together with the water movement. In this study, therefore, quantitative evaluation of the treatment processes inside the MSL system was conducted using laboratory-scale MSL systems, which were set up in 10 cm (depth) × 50 cm (width) × 23–73 cm (height) acrylic boxes enclosing “soil mixture blocks” alternating with permeable zeolite layers. Six MSL systems consisting of one to six soil mixture layers (SML) were constructed, and treated water from the SML and the permeable layers between the SML (PLb) was collected separately at the bottom of each system. In order to determine the treatment processes inside the system, wastewater, with mean concentrations of biological oxygen demand (BOD) 28.1 mg L−1, chemical oxygen demand (COD) 65.7 mg L−1, total nitrogen 9.8 mg L−1, total phosphorus 1.0 mg L−1, was introduced into the system at a hydraulic loading rate of 1000 L m−2 day−1. Concentrations of both BOD and COD in the SML were lower than those in the PLb. As the flow rate in the SML decreased and the rate in the PLb increased, concentrations increased in the PLb in each system. Although the removal rate of BOD always exceeded 80% in the systems with more than three layers, six layers were required for COD to be reduced to the same extent as BOD. Phosphorus concentrations were also lower in the SML than in the PLb due to the adsorption of phosphorus by the soil and mixed iron particles. Therefore, phosphorus removal efficiency was strongly influenced by flow rate in the SML. In this study, the ammonium adsorption and nitrification were almost completed down to the third layer of the MSL system. However, the removal of nitrogen did not proceed much below the fourth layer due to low denitrification efficiency.