纳米羟基磷灰石对土壤镉化学形态和水稻镉吸收的影响

Effect of nano-hydroxyapatite on Cd chemical speciation in soil and Cd accumulation in rice

采用吸附等温试验和盆栽试验,研究了nano-HAP对镉的吸附行为和对土壤镉化学形态及水稻Cd吸收的影响。吸附等温试验结果表明,nano-HAP对镉离子有很高的吸附能力,且其吸附行为可用Langumir方程和Freundlich方程很好地描述;盆栽试验结果表明,nano-HAP明显提高了土壤溶液中pH值,显著降低了土壤Cd的生物有效性,0.5%、1%和2%施用量的nano-HAP处理下生物有效态Cd含量分别下降63.21%、80.62%和92.32%。nanoHAP对Cd污染下的盆载水稻生长也有一定的促进作用,并显著降低了盆栽水稻籽粒中Cd的含量,且全部达到国家规定的可食用标准。

The adsorption behavior of Cd on the surface of Nano-hydroxyapatite（nano-HAP） and the effect of nanoHAP on the chemical speciation of Cd in soil and the Cd accumulation in rice were studied by the adsorption isotherm tests and pot experiments. The results showed that nano-HAP had a high adsorption capacity for Cd and the adsorption behavior could be well described by Langumir and Freundlich equations. The results of pot experiments showed that nanoHAP significantly increased the pH of soil solution and inhibited Cd bioavailability. The bioavailability of Cd concentration in the soil decreased by 63.21%, 80.62% and 92.32% under the 0.5%, 1% and 2% nano-HAP treatments, respectively.Nano-HAP significantly reduced the Cd content in rice grain and all rice grain met the edible standards.