叶面喷施铁肥对菜心重金属累积的影响

盆栽试验的方法研究了叶面喷施硫酸亚铁（FeSO4）、柠檬酸铁（FeC6H5O7）和EDTA二钠亚铁（EDTA·Na2Fe）3种铁肥对芸薹属叶菜类蔬菜菜心（Brassica parachinensis）Cd、Pb、Cu和Zn累积的影响。结果表明,与未喷施铁肥的清水（CK）处理相比,喷施铁肥使菜心Cd、Pb和Cu浓度分别降低4.30%-35.5%、6.17%-50.3%和8.34%-33.4%,Zn浓度变化为-27.1%-19.6%,Fe浓度提高42.6%-90.2%。柠檬酸铁和硫酸亚铁处理菜心产量比CK处理分别提高6.95%和18.2%,而EDTA二钠亚铁处理降低16.0%。叶面喷施铁肥可降低菜心Cd、Pb和Cu积累,并可提高Fe含量,其中以EDTA二钠亚铁处理效果最佳。

不同钝化剂对污染土壤中多重金属的固定

采用钝化剂培养试验,研究施加沸石、石灰、赤泥和花生壳炭4种钝化剂对酸性多重金属污染土壤Cd、Pb、Cu和Zn的固化效果,以期筛选出对其固定效果较好的钝化剂。结果表明:施用沸石、石灰、赤泥和花生壳炭土壤pH值分别显著升高0.51～1.02、0.82～1.29、0.72～0.89和0.30～0.35;4种钝化剂对土壤中Cd和Zn固化效果的影响依次为石灰>赤泥>沸石>花生壳炭,对Pb固化效果的影响依次为赤泥>石灰>沸石>花生壳炭,对Cu固化效果的影响依次为赤泥>石灰>花生壳炭>沸石;土壤CaCl_2提取态Cd、Pb、Cu和Zn含量随着4种钝化剂施用量的增加而降低,石灰和赤泥对Cd、Pb、Cu和Zn均有较好的固定效果,施加低量(2.5 g/kg)石灰和赤泥土壤CaCl_2提取态Cd、Pb、Cu和Zn含量降低程度分别在41%、84%、76%和83%以上。可知,土壤pH值与CaCl_2提取态Cd、Pb、Cu和Zn含量均呈显著负相关(P <0.01),石灰和赤泥在低施用量时对酸性多重金属污染土壤Cd、Pb、Cu和Zn具有的固定效果。

混配铁肥喷施对小白菜镉铅含量的影响

采用土壤盆栽实验,研究了叶面喷施不同配比硫酸亚铁、柠檬酸、乙二胺四乙酸二钠(Na_2EDTA)和尿素混配铁肥对小白菜生长及小白菜地上部Cd、Pb和Fe含量的影响。结果表明,喷施不同配比的混配铁肥对小白菜地上部干重及地上部Cd、Pb、Fe、Zn和Cu含量有明显不同的影响。叶面喷施FeSO_4混配肥提高了小白菜地上部生物量,喷施混配铁肥处理小白菜鲜重和干重分别增加24.63%~89.03%和34.78%~114.13%。喷施不同配比混配铁肥可在一定程度上降低小白菜地上部Cd、Pb、Cu和Zn含量,提高小白菜地上部Fe含量。喷施2 mmol/L FeSO_4+1.8 mmol/L柠檬酸+0.2 mmol/L Na_2EDTA+0.2%尿素(处理9)后,小白菜地上部Cd和Pb含量降低幅度分别在50%和40%以上,Fe含量提高16.35%;是小白菜降镉铅效果最优混配铁肥组合。

Fixation of Multiple Metals in Contaminated Soil by Different Passivators

The effects of 4 passivators, zeolite, lime, red mud and peanut shell biochar, on the fixation of Cd, Pb, Cu and Zn in acidic multi-metal contaminated soils were studied by passivator culture experiment in order to screen out the passivator with better fixation effects. The results showed that the soil pH values of zeolite, lime, red mud and peanut shell biochar increased significantly by 0.511.02, 0.821.29, 0.720.89 and 0.300.35 respectively. The effects of 4 passivators on the fixation of Cd and Zn in soil are lime>red mud>zeolite>peanut shell biochar. The order of effects on the fixation of Pb is red mud>lime>zeolite>peanut shell biochar. The order of the fixation effects of Cu is red mud>lime>peanut shell carbon>zeolite. The contents of Cd, Pb, Cu and Zn in the extractable state of CaCl2 decreased with the increase in the dosage of 4 passivators. Lime and red mud showed good fixation effects on Cd, Pb, Cu and Zn. The contents of Cd, Pb, Cu and Zn in the extractable state of CaCl2 at the low dosage(2.5 g/kg) of lime and red mud decreased by 41%, 84%, 76% and 83% respectively. Soil pH value was negatively correlated with CaCl2-Cd, Pb, Cu and Zn(P<0.01). Lime and red mud had significant fixation effects on Cd, Pb, Cu and Zn in acidic multi-metal contaminated soils at low application dosages.