Department of Natural Resources and Environmental Design, North Carolina A&T State University, Greensboro, North Carolina, USA.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2010;45(7):803-9. doi: 10.1080/10934521003708927.
Increased swine production in North Carolina has resulted in greater waste generation and is demanding some emerging new innovative technologies to effectively treat swine wastewater. One of the cost-effective and passive methods to treat swine wastewater is using constructed wetlands. The objective of this study was to evaluate the N removal under two N loads in 3 different wetland systems: aerated marsh-pond-marsh (M-P-M), aerated marsh-covered pond-marsh (M-FB-M), and continuous marsh (CM) with two days drain and five days flood cycle. Swine wastewater from an anaerobic lagoon was applied to the constructed wetland cells (11 m wide x 40 m length) at two N loading rates of 7 and 12 kg N ha(-1) day(-1)from June to July and August to September 2005, respectively. Weekly inflow and outflow samples were collected for N, P, TS, and COD analysis. Total N reductions (%) at low and high N loading rates were 85.8 and 51.8; 86.3 and 63.3; and 86.2 and 61.8 for M-P-M, M-FB-M, and CM, respectively. Aeration had no significant (P > 0.05) impact on N removal. However, significant (P < 0.05) differences were observed for wetland systems between low and high N loading rates. No difference (P > 0.05) in N reduction was found among wetland systems. Vegetation uptake of N was negligible, ranging from 1.2 to 1.8 %. No significant (P > 0.05) differences in TS and COD removal were observed between the wetland systems.
北卡罗来纳州生猪产量的增加导致了更多的废物产生，并需要一些新兴的创新技术来有效处理养猪废水。用人工湿地处理养猪废水是一种具有成本效益和被动的方法。本研究的目的是在 3 种不同湿地系统（充氧沼泽-池塘-沼泽（M-P-M）、充氧沼泽覆盖池塘-沼泽（M-FB-M）和连续沼泽（CM））中，评估在两种氮负荷下的氮去除情况：两种氮负荷分别为 7 和 12 kg N ha(-1) day(-1)，试验周期分别为 2005 年 6 月至 7 月和 8 月至 9 月。从 6 月至 7 月和 8 月至 9 月，分别以 7 和 12 kg N ha(-1) day(-1)的氮负荷将来自厌氧塘的养猪废水应用于人工湿地单元（11 m 宽×40 m 长）。每周采集进水和出水样进行氮、磷、总固体和化学需氧量分析。在低氮和高氮负荷下，M-P-M、M-FB-M 和 CM 的总氮去除率（%）分别为 85.8 和 51.8；86.3 和 63.3；86.2 和 61.8。曝气对氮去除没有显著影响（P > 0.05）。然而，在低氮和高氮负荷下，湿地系统之间存在显著差异（P < 0.05）。湿地系统之间的氮去除率没有差异（P > 0.05）。氮的植物吸收可忽略不计，范围为 1.2%至 1.8%。湿地系统之间的总固体和化学需氧量去除率没有显著差异（P > 0.05）。
