赤泥对堆肥腐熟度及其产品对稻米Cd阻控效果

以赤泥作为堆肥添加剂进行鸡粪好氧堆肥试验，分析了堆肥过程中赤泥对温度、pH值、电导率（EC）及种子发芽指数（GI）的影响.通过三维荧光与紫外-可见光光谱特征解析堆肥过程中腐殖酸（HA）组分的演变特征.并利用盆栽实验探索堆肥产品对矿区土壤中稻米镉的阻隔效果.结果表明，赤泥的添加提高了堆体高温期的温度.EC较堆肥前均显著降低，但赤泥堆肥EC （4.29mS/cm）显著高于鸡粪堆肥EC （3.59mS/cm）.鸡粪堆肥与赤泥堆肥的GI随着堆肥时间的增长而升高，在堆肥结束时分别达到100.2%和96.44%，说明2种堆肥产品均未表现出植物毒性.2种堆肥HA中类蛋白质等物在堆肥过程中均转化为较为稳定的类腐殖质物质，HA的SUVA₂₅₄、SUVA₂₈₀和A_226~400在堆肥结束后也显著提高，表明堆肥的腐殖化程度升高.此外，赤泥的添加提高了腐殖化参数数值，证明赤泥的加入能够加速堆肥腐殖化进程.在盆栽实验中，鸡粪堆肥与赤泥堆肥均提高了土壤的pH值，降低了土壤中DTPA-Cd和糙米中Cd的含量.其中，施用2g/kg赤泥堆肥后，糙米Cd含量降低幅度最大，为58.68%，水稻糙米中Cd的含量由未施用堆肥的0.42mg/kg降低至0.17mg/kg.因此，赤泥的添加可以在一定程度上提高堆肥效率，同时施加堆肥产品对土壤Cd的生物有效性及水稻植株内Cd起到抑制与阻隔作用，且施加赤泥堆肥效果更为显著.

Effects of red mud on compost maturity and Cd resistance control of rice

Red mud was used as an additive to conduct aerobic composting experiments of chicken manure for evaluating effects of red mud on temperature, pH, electrical conductivity (EC), and seed germination index (GI) during composting. The evolution characteristics of humic acid (HA) components during composting were analyzed by combining three-dimensional fluorescence with ultraviolet-visible light spectrum; and the pot experiments were also conducted to explore the barrier effect of compost products on rice cadmium in the mining soil. The results showed that red mud increased the temperature of the compost during the high temperature period. The EC of both groups decreased significantly after composting, however, the EC of red mud compost (4.29mS/cm) was much higher than that of chicken manure compost (3.59mS/cm).The GI of chicken manure compost and red mud compost increased with composting time by; 100.2% and 96.44%, respectively, at the end of composting, indicating that the products of neither red mud compost nor chicken manure compost exhibited phytotoxicity. The protein-like substances in the HA of the two kinds of composts were converted into relatively stable humus-like substances throughout the composting process. A significant increase in SUVA₂₅₄, SUVA₂₈₀, and A_226-400 of HA indicates the elevated humification degree of compost. In addition, red mud could optimize the humification parameters, implying that the addition of red mud can accelerate the humification process of the heap. In pot experiments, both chicken manure compost and red mud compost increased soil pH and reduced the concentration of DTPA-Cd in soil and total Cd in brown rice. After applying 2g/kg red mud compost, the Cd content in brown rice decreased significantly (by 58.68%) from 0.42mg/kg to 0.17mg/kg after composting. Therefore, red mud can accelerate the composting efficiency to a certain extent. The application of compost products can inhibit the bioavailability of Cd in both soil and rice plants, and an addition of red mud can lead to a higher composting efficiency.