Based on sufficient pollutants in pretreated swine wastewater (PSW), this study aimed to explore feasibility of growing water spinach (WS) in a hydroponic system using PSW as a liquid fertilizers in a hydroponic system. The tolerance values of WS to Cu(Ⅱ), Zn(Ⅱ), total phosphorus (TP), and ammonium-N (NH4 +-N) in culture solution were found to be 0.5, 2.0, 150, and 300 mg·L−1, respectively, in the hydroponic systems. The fresh stem-leaf production of WS in undiluted PSW increased by 38.9% compared to the control group (Formula B of leafy vegetable solution culture in South China Agricultural University), and the concentration of nutrients (chlorophyll a, chlorophyll b, β-carotene, and sugar) of WS was also higher than the control group. The concentration of Pb(Ⅱ), Hg(Ⅱ), As(Ⅴ), and Cr(Ⅱ) in WS was all below the safety standard content for agriculture production in China. After 20 d hydroponic culture, the NH4 +-N, TP, Cu(Ⅱ), and Zn(Ⅱ) concentration in PSW significantly decreased to 19.77 (<80), 3.32 (<8.0), 0.15(<2.0), and 0.54 (<5.0) mg·L−1, corresponding to removal rate of 87.91%, 92.38%, 64.29%, and 49.53%, respectively, which met the national discharge standard of livestock wastewater in China.
Bibliographical noteFunding Information:
This work was supported by the Research Project of State Key Laboratory of Food Science and Technology Nanchang University in China (Project No. SKLF-ZZB-201722); Key project of Jiangxi Provincial Department of Science and Technology Jiangxi ( 20161BBF60057 ) in China; the National Natural Science Foundation of China ( 21466022 , 21878139 ) in China; Special fund for Jiangxi Province ( GCXZ2014-124 100102102082 ) For Financial support in China; Fund of national study abroad in China.
- Heavy metal
- Hydroponic system
- NH -N
- Swine wastewater
- Water spinach