In situ immobilization of heavy metals in contaminated soils using industrial by-products is an attractive remediation technique. In this work, titanium gypsum (TG) was applied at two levels (TG-L: 0.15% and TG-H: 0.30%) to simultaneously reduce the uptake of cadmium (Cd), lead (Pb) and arsenic (As) in rice grown in heavy metal contaminated paddy soils. The results showed that the addition of TG significantly decreased the pH and dissolved organic carbon (DOC) in the bulk soil. TG addition significantly improved the rice plants growth and reduced the bioavailability of Cd, Pb and As. Particularly, bioavailable Cd, Pb and As decreased by 35.2%, 38.1% and 38.0% in TG-H treatment during the tillering stage, respectively. Moreover, TG application significantly reduced the accumulation of Cd, Pb and As in brown rice. Real-time PCR analysis demonstrated that the relative abundance of sulfate-reducing bacteria increased with the TG application, but not for the iron-reducing bacteria. In addition, 16S rRNA sequencing analysis revealed that the relative abundances of heavy metal-resistant bacteria such as Bacillus, Sulfuritalea, Clostridium, Sulfuricella, Geobacter, Nocardioides and Sulfuricurvum at the genus level significantly increased with the TG addition. In conclusion, the present study implied that TG is a potential and effective amendment to immobilize metal(loid)s in soil and thereby reduce the exposure risk of metal(loid)s associated with rice consumption.

使用工业副产品在污染土壤中原位固定重金属是一种有吸引力的修复技术。在这项工作中，以两种含量（TG-L：0.15％和TG-H：0.30％）施用钛石膏（TG），以同时减少镉（Cd），铅（Pb）和砷（As）的吸收。在重金属污染的稻田中生长的水稻。结果表明，TG的添加显着降低了pH值和散装土壤中的溶解有机碳（DOC）。TG的添加显着改善了水稻的生长，降低了Cd，Pb和As的生物利用度。特别是，在分-期，TG-H处理的生物利用态Cd，Pb和As分别下降了35.2％，38.1％和38.0％。此外，TG的施用显着减少了糙米中Cd，Pb和As的积累。实时PCR分析表明，硫酸盐还原菌的相对丰度随着TG的应用而增加，但对于铁还原菌却没有。此外，通过16S rRNA测序分析发现，重金属抗性细菌的相对丰度例如芽孢杆菌，Sulfuritalea，梭状芽孢杆菌，Sulfuricella，地杆菌，诺卡氏菌和Sulfuricurvum在属的水平与TG此外显著上升。总而言之，本研究暗示TG是一种潜在且有效的改良剂，可以固定土壤中的金属（金属），从而降低与稻米消费相关的金属（金属）的暴露风险。