Abstract:
A bio-matrix material (BMM) system is used to pretreat swine wastewater and reduce the nitrogen (N) concentration to the tolerance range of plants in constructed wetlands. In this study, rice straw (RS), wheat straw (WS), and corn stalk (CS) were applied to treat pollutants from swine wastewater, respectively. This one year-long field experiment make up for the lack of long-term experiments and mechanistic investigations of BMM. The pollutant removal efficiency, degradation process of crop straw, and the abundance of nitrogen cycling genes were determined in different BMM systems. The results showed that the removal efficiency of COD, TN, NH4+, and NO3- was the best in the initial 6 months. Furthermore, RS and WS exhibited favorable annual removal efficiency of TN and NH4+, which were 32.81% and 32.99%, 35.3% and 34.97%, respectively. Moreover, the removal efficiency of COD was 30.81% in three BMM systems. Meanwhile, it was found that the dry matter (DM) degradation of crop straws was fast in the first 4-5 months. The degradation rates of cellulose, hemicellulose, and lignin were 94.19%, 94.36%, and 87.32%, respectively, in 1 year. The abundance of nitrogen cycling genes significantly increased by adding BMM, compared with CK (P < 0.05). This showed the abundance of the hzsB gene in RS was the highest, while nirK, nirS, AOA, and AOB were the highest in WS. The addition of RS and WS was better than that of CS in promoting the abundance of nitrogen cycling microorganisms. The results indicated that adding BMM could enhance the anaerobic ammonia oxidation, nitrification, and denitrification. This study not only extends our comprehension of BMM mechanisms in swine wastewater treatment but also serves as a guiding light for numerous farms in similar climate regions.
摘要:
生物基质材料(BMM)系统用于预处理猪废水,并将氮(N)浓度降低到人工湿地中植物的耐受范围。在这项研究中,稻草(RS),小麦秸秆(WS),玉米秸秆(CS)用于处理养猪废水中的污染物,分别。这项为期一年的现场实验弥补了BMM长期实验和机理研究的不足。污染物去除效率,农作物秸秆的降解过程,并在不同的BMM系统中确定了氮循环基因的丰度。结果表明,对COD的去除效率,TN,NH4+,在最初的6个月中,NO3-是最好的。此外,RS和WS对TN和NH4+的年去除效果良好,分别为32.81%和32.99%,35.3%和34.97%,分别。此外,在三个BMM系统中,COD的去除率为30.81%。同时,发现农作物秸秆的干物质(DM)降解在前4-5个月内是快速的。纤维素的降解率,半纤维素,木质素占94.19%,94.36%,和87.32%,分别,在1年。通过添加BMM,氮循环基因的丰度显着增加,与CK比较(P<0.05)。这表明RS中hzsB基因的丰度最高,而nirk,nirs,AOA,和AOB在WS中最高。RS和WS的添加在促进氮循环微生物丰度方面优于CS。结果表明,添加BMM可以增强厌氧氨氧化,硝化,和反硝化。这项研究不仅扩展了我们对猪废水处理中BMM机制的理解,而且还为类似气候地区的许多农场提供了指路明灯。