Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China.
Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
J Environ Manage. 2021 May 1;285:112101. doi: 10.1016/j.jenvman.2021.112101. Epub 2021 Feb 17.
The bioavailability of heavy metals in compost is critical for their agronomic value. The effect of inorganic additives (rock phosphate, PR and boron waste, BW) on Copper (Cu) and Zinc (Zn) bioavailability during co-compost of swine manure and rice straw was assessed using sequential extraction procedure (European Community Bureau of Reference). The result showed that both additives, applied at rates of 2.5%-7.5% (w/w) could promote the change of exchangeable Cu and reducible Cu into oxidizable Cu, thereby reducing their bioavailability factor (BF) by 15.5%-47.2%. While additives provided no significant reduction in BF of Zn, the shift from exchangeable Zn into reducible Zn can still reduce the mobility of Zn. Based on redundancy analysis (RDA), organic matter (OM) and electrical conductivity (EC) were identified as the most important controlling factors for redistribution of Cu and Zn fractions during composting. The inorganic additives strengthened the passivation of Cu and Zn bioavailability by stimulating OM degradation. The 7.5% (w/w) rock phosphate showed best passivating effect on the bioavailability of Cu.
堆肥中重金属的生物有效性对于其农业价值至关重要。采用连续提取程序（欧盟基准局）评估了无机添加剂（磷矿粉、PR 和硼废物、BW）对猪粪和稻草共堆肥过程中铜（Cu）和锌（Zn）生物有效性的影响。结果表明，两种添加剂（添加量为 2.5%-7.5%（w/w））都可以促进可交换态 Cu 和可还原态 Cu 向可氧化态 Cu 的转化，从而降低其生物有效性因子（BF）15.5%-47.2%。虽然添加剂对 Zn 的 BF 没有显著降低，但可交换态 Zn 向可还原态 Zn 的转化仍可以降低 Zn 的迁移性。基于冗余分析（RDA），有机质（OM）和电导率（EC）被确定为堆肥过程中 Cu 和 Zn 形态重新分布的最重要控制因素。无机添加剂通过刺激有机质降解，增强了 Cu 和 Zn 生物有效性的钝化作用。7.5%（w/w）的磷矿粉对 Cu 的生物有效性表现出最好的钝化效果。
