三种秸秆材料处理养猪废水除磷效果及磷形态变化特征研究

利用人工湿地处理养殖场废水具有良好效果和可资源化利用的显著优势,但养殖场废水一般养分浓度过高,湿地植物难以耐受,采用适当措施降低养分浓度是生态治理的重要前提。为此选取麦秸、玉米秆、稻草三种南北方常见的农作物秸秆作为生物基质材料,建立三级生物基质处理系统,开展为期6个月的野外控制试验,以期探明生物基质处理系统对高负荷养殖废水中磷的去除效果及磷形态的变化特征。结果表明,利用秸秆材料可以有效去除高负荷养殖废水中的磷,其中总磷(TP)和溶解态无机磷(DIP)去除率平均可达40.1%和35.9%,出水TP和DIP平均浓度分别可降至54.35～62.35 mg/L和22.68～23.25 mg/L,达到绿狐尾藻生态湿地的耐受范围之内(73 mg/L)。生物基质处理系统对磷的去除主要以颗粒态磷在生物基质处理系统中的物理沉淀为主,平均占磷素总去除量的57.5%;养殖废水中DIP的去除率与水温(T)、pH值呈显著正相关(P 0.05),而与溶解氧(DO)和氧化还原电位(Eh)的相关性不显著(P 0.05)。三种秸秆基质材料对磷素的去除能力有一定差异,当磷素去除率显著下降时需要对秸秆材料进行补充,建议稻草和麦秸的补充周期为90 d,而玉米秆的补充周期为120 d。本试验对于养殖废水污染的生态治理具有重要理论价值和指导意义。

Study on phosphorus removal efficiency and changes in phosphorus forms using three kinds of straw material to treat swine wastewater

Constructed wetlands have good effect on treating swine wastewater. However, wetland plants are difficult to tolerate the too high nutrient concentrations of swine wastewater. Here in, nutrient concentrations should be reduced using appropriate measures. In this study, three common crop straw materials were selected as the biological matrix materials, i.e. wheat, corn stalk, and rice straw. A three-stage biomatrix treatment system (BMTS) was established. A controlling field experiment treating swine wastewater was conducted for 6 months. The study aims to investigate the phosphorus removal efficiency and changes in phosphorus forms in BMTS . Results showed that phosphorus was effectively removed in the BMTS. The removal efficiency of TP and DIP were 40.1% and 35.9%, respectively. The average effluent concentrations of TP and DIP were reduced to 54.35 - 62.35 mg/L and 22.68 - 23.25 mg/L, respectively. These concentrations were within the tolerance range of Myriophyllum elatinoides (<73 mg/L). The phosphorus removal in the BMTS was mainly based on the physical precipitation of particulate phosphorus, and accounted for 57.5% of TP removal. The DIP removal was significantly positively related to water temperature (T) and pH (P< 0.05), but not significantly related to DO and Eh (P> 0.05). There were differences in removal ability in the studied three straw to a certain extent. Straw material needs to be added when the removal rate drops. Recommended addition cycle is 90 days for wheat straw and rice straw, but 120 days for corn stalk. This study is of importance both in theoretical value and in practice significance for guiding swine wastewater ecological treatment.