几种钝化剂修复铅镉污染石灰性土壤的效果研究

发布时间：2018-04-23 12:30

本文选题：钝化剂 + 铅　；参考：《河南农业大学》2015年硕士论文

【摘要】：土壤重金属污染已经成为世界性的重大问题,如何治理和修复重金属污染耕地,以实现农产品质量安全成为了当务之急。为了探讨几种钝化剂对铅镉污染石灰性土壤的修复效果,筛选适合治理北方石灰性铅镉污染土壤的钝化剂,采用了土壤模拟培养试验及盆栽试验,研究了磷酸盐类、天然改性人工合成矿物类、有机类等14种钝化剂的修复效果。结果表明:1.膨润土、磷酸二氢钾、生物质炭、改性生物质炭、3 g·kg-1多效菌、海泡石、3000目伊利石、800目伊利石、鸡粪和菌肥对土壤铅有钝化效果。对土壤铅钝化效果最好的为磷酸二氢钾处理,其次为改性生物质炭处理。2.9 g·kg-1膨润土、磷酸二氢钾、生物质炭、改性生物质炭、9 g·kg-1和12 g·kg-1分子键合TM稳定剂、3 g·kg-1和6 g·kg-1多效菌、海泡石、3000目伊利石、800目伊利石、3 g·kg-1茶多酚、15 mg·kg-1和20 g·kg-1鸡粪、15 mg·kg-1和20 g·kg-1菌肥对土壤镉有钝化效果。对土壤镉钝化效果最好的为改性生物质炭处理,其次为磷酸二氢钾处理。3.9 g·kg-1磷酸二氢钾、生物质炭和20 g·kg-1改性生物质炭对有效态铅的减少量在各时间段之间基本不变;3 g·kg-1、6 g·kg-1磷酸二氢钾和10 g·kg-1改性生物质炭对有效态铅的减少量在各时间段之间略有增加;15 mg·kg-1改性生物质炭对有效态铅的钝化率从2周到4周增加显著。在4个时间段内,不同添加量的磷酸二氢钾、生物质炭和改性生物质炭均可使土壤中的弱酸提取态、还原态铅减少,残渣态增加,效果最明显的为磷酸二氢钾,且随着钝化剂添加量的增加,弱酸提取态、还原态铅逐渐减少,残渣态逐渐增加。4.6 g·kg-1磷酸二氢钾和10 g·kg-1、15 g·kg-1生物质炭对有效态镉的减少量在各时间段之间基本不变;9 g·kg-1磷酸二氢钾和10 g·kg-1改性生物质炭对有效态镉的减少量在各时间段之间略有增加;3 g·kg-1磷酸二氢钾、20 g·kg-1生物质炭和15 g·kg-1、20 g·kg-1改性生物质炭对有效态镉的减少量在各时间段之间显著提高。在4个时间段内,不同添加量的磷酸二氢钾、生物质炭和改性生物质炭均可使土壤中的弱酸提取态、还原态镉减少,残渣态增加,效果最明显的为改性生物质炭,且随着钝化剂添加量的增加,弱酸提取态、还原态镉逐渐减少,残渣态逐渐增加。5.不同添加量的磷酸二氢钾、生物质炭和改性生物质炭均可使小麦株高增加,茎叶和根中的铅、镉含量降低,对小麦铅、镉吸收的控制效果排序为磷酸二氢钾改性生物质炭生物质炭。6.不同添加量的磷酸二氢钾、生物质炭和改性生物质炭均可减少盆栽土壤中有效态铅、镉的含量,但与土壤模拟培养试验结果不同的是,对土壤中有效态铅、镉钝化效果最好的均为磷酸二氢钾。磷酸二氢钾可有效的将土壤中弱酸提取态和还原态铅、镉转换成残渣态,生物质炭和改性生物质炭,则将土壤中弱酸提取态和还原态铅、镉转换成氧化态和残渣态。7.添加磷酸二氢钾后,通过与铅形成难溶的磷酸铅化合物Pb3(P3O9)2·3(H2O)来降低铅的生物有效性。经过磷酸改性后的生物质炭表面形态发生了较大的变化,活化后生物质炭的比表面积急剧增大,为其更多的吸附重金属提供了可能。
[Abstract]:Heavy metal pollution in soil has become a major problem in the world. It is urgent to control and repair the heavy metal polluted land to realize the quality and safety of agricultural products. In order to explore the effect of several passivating agents on the remediation of lead and cadmium contaminated soil, the selection of passivating agent suitable for the treatment of soil contaminated with calcareous lead and cadmium in the north is adopted. Soil simulated culture experiments and pot experiments were conducted to study the restoration effects of 14 kinds of passivating agents such as phosphate, natural modified synthetic minerals and organic compounds. The results showed that 1. bentonite, potassium dihydrogen phosphate, biomass carbon, modified biomass carbon, 3 G. Kg-1 multieffect bacteria, sea vesicles, 3000 mesh illite, 800 mesh illite, chicken manure and bacterial fertilizer to soil Lead passivation effect. The best effect for soil lead passivation is potassium dihydrogen phosphate treatment, followed by modified biomass carbon treated.2.9 G. Kg-1 bentonite, potassium dihydrogen phosphate, biomass carbon, modified biomass carbon, 9 g. Kg-1 and 12 g kg-1 molecular bond stabilizer, 3 g kg-1 and 6 g kg-1 multi effect bacteria, sepiolite, 3000 mesh illite, 800 mesh Illite The effect of 3 G. Kg-1 tea polyphenols, 15 mg. Kg-1 and 20 g. Kg-1 chicken manure, 15 mg kg-1 and 20 g kg-1 bacterial fertilizer on soil cadmium passivation effect. The best effect on soil cadmium passivation is treated with modified biomass carbon, followed by potassium dihydrogen phosphate treatment,.3.9 g, potassium dihydrogen phosphate, biomass carbon and 20 biomass carbon to reduce the amount of effective lead The reduction of effective lead by 3 G. Kg-1,6 G. Kg-1 phosphate dihydrogen phosphate and 10 g. Kg-1 modified biomass carbon increased slightly between different time periods, and the passivation rate of effective lead in 15 mg. Kg-1 modified biomass carbon increased significantly from 2 to 4 weeks. In 4 time periods, different amounts of potassium dihydrogen phosphate were added, Biomass charcoal and modified biomass carbon can make the weak acid in the soil extract, reduce the reduced state lead and increase the residue state, the most obvious effect is potassium dihydrogen phosphate, and with the increase of the amount of passivating agent, the weak acid extraction state, the reduced state lead gradually decrease, the residue state gradually increases.4.6 g kg-1 potassium dihydrogen phosphate and 10 g. Kg-1,15 G. Kg-1 biology. The reduction of effective cadmium to effective cadmium is basically unchanged between different time periods; the reduced amount of effective cadmium by 9 g kg-1 potassium dihydrogen phosphate and 10 g. Kg-1 carbon is slightly increased in each time period; 3 G. Kg-1 phosphate dihydrogen phosphate, 20 g. Kg-1 biomass carbon and 15 g kg-1,20 G. In the 4 time periods, different additions of potassium dihydrogen phosphate, biomass charcoal and modified biomass carbon can make the weak acid in the soil extract, the reduced state cadmium decreased, the residue state increased, the most obvious effect was the modified biomass carbon, and with the increase of the amount of passivating agent, the extraction of weak acid and the reduced state cadmium. Gradually decreasing, the residue state gradually increased.5. different amount of potassium dihydrogen phosphate, biomass carbon and modified biomass carbon can increase wheat plant height, lead and cadmium content in stem and root and root, cadmium content of wheat lead, cadmium absorption of potassium dihydrogen phosphate modified biogenic charcoal.6. potassium dihydrogen phosphate, different amount of potassium phosphate, Biomass charcoal and modified biomass carbon can reduce the content of effective lead and cadmium in potted soil, but different from the results of soil simulated culture test, the best effect of cadmium passivation in soil is the potassium dihydrogen phosphate. Potassium dihydrogen phosphate can effectively extract the weak acid in the soil and the reduced lead, and convert the cadmium into the residue state. Biomass charcoal and modified biomass charcoal, then the bioavailability of lead was reduced by the conversion of cadmium into oxidizing and residue.7. with potassium dihydrogen phosphate, and the bioavailability of lead was reduced by the formation of a difficult lead phosphate compound Pb3 (P3O9) 2. 3 (H2O) with lead. The surface morphology of biomass carbon after phosphoric acid modification was larger. The specific surface area of activated carbon increased sharply after the change, which provided more possibilities for absorbing heavy metals.

【学位授予单位】：河南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X53

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