通过盆栽试验,研究了不同浓度镉模拟污水絮凝除镉处理后的"再生水"浇灌水稻对其生长的影响和Cd在其中的迁移分布状况.结果表明,0.1 和 0.5 mg/L的两种模拟污水絮凝后的清液Cd浓度≤0.01 mg/L、pH=5-8.5,达到中国农田灌溉水质标准,将其浇灌栽培水稻,所得稻谷Cd含量分别为0.07 和 0.13 mg/kg,达到中国食品安全国家标准(谷物镉残留≤0.2 mg/kg);抽穗期叶绿素含量、分蘖期分蘖数、稻谷产量均随着Cd浓度提高逐渐降低;同等浓度Cd模拟污水与絮凝除镉处理后的含Cd上清液浇灌水稻,对水稻生长具有同等效应;成熟后水稻根、茎和谷Cd含量依次为根>茎>谷.
In this study,the effects of"reclaimed water"prepared through the flocculation treatment of the simulated cadmium-containing wastewater on the growth of rice,and the migration and distribution of Cd in rice were studied by pot experiment.The results showed that the concentration of Cd in the"reclaimed water"after flocculation treatment of the simulated wastewater with the Cd concentration of 0.1 and 0.5 mg/L was≤0.01 mg/L,pH value was 5-8.5,meeting the Standard for Irrigation Water Quality(GB 5084-2021).When irrigated,the Cd content of rice was 0.07 and 0.13 mg/kg,respectively,meeting the National Food Safety Standard.The comparison of cadmium-containing effluent and"reclaimed water"revealed that the chlorophyll content at the heading stage,the number of tillers at the tillering stage,and the yield of rice after maturity all decreased progressively with the increase of Cd concentration,whereas the effluent with the equivalent Cd concentration and"reclaimed water"had the same effect on rice growth,and the Cd content in rice was the highest in roots,followed by stems and grain.