Passivating effect of compound passivating agent on cadmium pollution in facility soil and effects on cadmium accumulation in plant
In order to clarify the passivation effect of compound passivation agents on the fa-cility soil contaminated with cadmium(Cd).The facility soil with exogenous Cd was stud-ied.Biological simulation method was adopted to explore the passivation effect of compound passivation agents of bone charcoal powder,biochar and nano-humus on Cd accumulation in pakchoi.The main results were as follows:(1)When the total amount of bone charcoal pow-der,biochar and nano-humus were 2％and 5％,and the proportion was 1∶5∶2,the passi-vation effect was most significant.The content of available Cd was significantly decreased by 12.72％-15.73％.It was easier to convert Cd form from weak acid extraction state to re-ducible,oxidizable and residue state.Soil pH value was significantly increased by 0.22-0.34 units,and soil available P content was significantly increased by 15.28％-23.73％.The activities of catalase and urease in soil were significantly increased by 23.21％-52.98％and 57.75％-67.75％.When the supplemental level was 5％,the content of Cd in aboveground of pakchoi was significantly decreased by 14.67％.When the total supplemen-tal level was 2％,the content of Cd in pakchoi root was significantly decreased by 14.47％.(2)Other treatments also showed some passivation effects.When the total addition amount was 5％,and the proportion of application was 1∶2∶2,the available Cd content in soil was significantly decreased by 10.93％.When the total addition amount were 2％and 5％,and the proportion of application was 1∶5∶5,the available Cd content in soil was significantly decreased by 7.49％-7.56％.(3)The correlation analysis showed that the increase of soil pH value would reduce the content of soil available Cd,and increase the content of soil avail-able P,catalase and urease activities;The increase of soil available Cd content could increase the content of Cd in the aboveground part of pakchoi,and soil available P content and cata-lase activity decreased.The decrease of available Cd content could reduce the content of Cd in the aboveground part of pakchoi.In conclusion,under different addition amounts and pro-portions of application,the compound passivation agents could effectively increase soil pH value,available P content,catalase and urease activities,decrease the available Cd content in soil and Cd content in pakchoi.In addition,further comprehensive analysis was conducted from the perspective of saving economic cost.It was recommended that the total addition a-mount of bone charcoal powder,biochar and nano-humus was 2％,and the proportion of combined application was 1∶5∶2,which had the best passivation effect on the facility soil contaminated with Cd.
bone charcoal powderbiocharnano-humusmixing passivating agentCd content of pakchoipassivation effect
NETL
NSTL
万方数据
维普
