Richter A Y, Weaver R W
Department of Soil & Crop Sciences, Texas A&M University College Station, TX, 77843-2474, USA.
Environ Technol. 2003 Dec;24(12):1561-7. doi: 10.1080/09593330309385702.
Subsurface flow constructed wetlands (SFCWs) are becoming increasingly common in on-site treatment of wastewater. Gravel is the most popular form of wetland fill medium, but tire chips provide more porosity, are less dense, and less expensive. This study determines the treatment efficiency of SFCWs filled with gravel or tire chip media to treat domestic wastewater. The influent and effluent of six SFCWs filled with tire chip medium and six SFCWs filled with gravel were monitored for 5 to 16 consecutive months. Parameters measured included pH, biochemical oxygen demand (BOD5), total and volatile suspended solids, NH4, P, and fecal and total coliforms. The only clear difference between medium types in wetland performance was for P. Soluble P in the effluent averaged 1.6 +/- 1.0 mg l(-1) in the tire chip-filled wetlands and 4.8 +/- 3.2 mg l(-1) in the gravel-filled wetlands. Most likely, Fe from exposed wires in shredded steel-belted tires complexed with P to create an insoluble compound. Tire chips may be a better fill medium for SFCWs than gravel because of higher porosity, lower cost, and greater reduction of P in effluent.
潜流人工湿地（SFCWs）在现场废水处理中越来越普遍。砾石是最常用的湿地填充介质形式，但轮胎碎片具有更高的孔隙率、更低的密度且成本更低。本研究确定了填充砾石或轮胎碎片介质的潜流人工湿地处理生活污水的效率。对六个填充轮胎碎片介质的潜流人工湿地和六个填充砾石的潜流人工湿地的进水和出水进行了连续5至16个月的监测。测量的参数包括pH值、生化需氧量（BOD5）、总悬浮固体和挥发性悬浮固体、NH4、P以及粪便和总大肠菌群。湿地性能方面介质类型之间唯一明显的差异在于P。在填充轮胎碎片的湿地中，出水的可溶性P平均为1.6±1.0 mg l(-1)，而在填充砾石的湿地中为4.8±3.2 mg l(-1)。很可能，来自碎钢丝轮胎中暴露电线的Fe与P络合形成了一种不溶性化合物。由于孔隙率更高、成本更低且出水P的减少量更大，轮胎碎片可能是比砾石更好的潜流人工湿地填充介质。
