Mineral materials as feasible amendments to stabilize heavy metals in polluted urban soils

Four minerals, agricultural limestone (AL), rock phosphate (RP), palygorskite (PG), and calcium magnesium phosphate (CMP), were evaluated by means of chemical fractions of heavy metals in soils and concentrations of heavy metals in leachates from columns to determine their ability to stabilize heavy metals in polluted urban soils. Two urban soils (calcareous soil and acidic soil) polluted with cadmium, copper, zinc and lead were selected and amended in the laboratory with the mineral materials) for 12 months. Results indicated that application of the mineral materials reduced exchangeable metals in the sequence of Pb, Cd > Cu > Zn. The reduction of exchangeable fraction of heavy metals in the soils amended with di erent mineral materials followed the sequence of CMP, PG > AL > RP. Reductions of heavy metals leached were based on comparison with cumulative totals of heavy metals eluted through 12 pore volumes from an untreated soil. The reductions of the metals eluted from the calcareous soil amended with the RP, AL, PG and CMP were 1.98%, 38.89%, 64.81% and 75.93% for Cd, 8.51%, 40.42%, 60.64% and 55.32% for Cu, 1.76%, 52.94%, 70.00% and 74.12% for Pb, and 28.42%, 52.74%, 64.38% and 49.66% for Zn. Those from the acidic soil amended with the CMP, PG, AL, and RP were 25.65%, 68.06%, 78.01% and 79.06% for Cd, 26.56%, 49.64%, 43.40% and 34.68% for Cu, 44.44%, 33.32%, 61.11% and 69.44% for Pb, and 18.46%, 43.77%, 41.98% and 40.68% for Zn. The CMP and PG treatments were superior to the AL and RP for stabilizing heavy metals in the polluted urban soils.     

改良剂对Cu、Cd污染土壤重金属形态转化的影响

采用室内培养的方法,比较石灰、钙镁磷肥、硅肥、紫云英、猪粪和泥炭等几种改良剂作用下Cu、Cd污染酸性水稻土中不同形态重金属的动态变化.结果表明,土壤添加石灰、钙镁磷肥、硅肥、紫云英和猪粪培养120d期间,土壤pH值呈现先增加至最大值而后缓慢降低的趋势,但均高于对照,而添加泥炭后土壤pH值略有下降.各改良剂的使用均显著降低了土壤水溶态和交换态Cu、Cd含量,且在培养期间呈现先逐渐降低至最小值而后再增加的趋势.相关分析结果表明,土壤水溶态和交换态Cu、Cd含量与土壤pH值之间均存在极显著的负相关关系.土壤添加改良剂后碳酸盐结合态、铁锰氧化物结合态、有机结合态和残渣态Cu、Cd含量均有不同幅度的增加,说明改良剂的应用能够使土壤重金属由有效态向某些潜在有效态或无效态转变,从而达到修复重金属污染土壤的目的.     

不同粒径羟基磷灰石对污染土壤铜镉磷有效性和酶活性的影响

为研究不同粒径羟基磷灰石对重金属污染土壤的修复效果,采用向污染土壤添加常规磷灰石（150 μm）、微米（3 μm）和纳米（40 nm）羟基磷灰石的田间原位试验方法,考察其钝化修复5 a后对土壤铜镉磷有效性和酶活性的影响.结果表明:3种粒径羟基磷灰石均提高了土壤pH,降低了土壤交换性酸和交换性铝的含量,且微米羟基磷灰石处理效果最好.常规磷灰石、微米和纳米羟基磷灰石处理分别使w（离子交换态铜）降低了62.6%、74.3%和70.4%,w（离子交换态镉）降低了15.7%、25.3%和26.7%.3种材料均增加了土壤w（TP）,其中4.61%~17.4%和73.4%~89.8%分别转化为树脂磷和稳定态磷.微米羟基磷灰石处理分别使土壤脲酶活性和微生物量碳含量提高了4.66和0.66倍.研究显示,微米羟基磷灰石更有利于铜和镉由活性态向非活性态转化,增加土壤磷的有效性,提高土壤微生物活性,在我国南方重金属污染红壤区具有较好的应用潜力.      

水铝钙石对不同镉污染农田重金属的钝化效果及机制

水铝钙石(Ca-Al-LDHs)是一种新型的层状复合金属氢氧化物,具有较大的比表面积、良好的阴离子交换性能和高稳定性的优点.本研究选择高Cd污染农田、中Cd污染农田和低Cd污染农田3种不同Cd污染水平的自然农田土壤作为研究对象.通过室内钝化实验,探讨水铝钙石对3种Cd污染农田土壤Cd、Pb、Zn有效态的变化规律以及形态转换的影响,进一步采用X射线衍射仪(XRD)和傅里叶变换红外光谱仪(FTIR)初步探讨其钝化机制.结果表明,在高中低这3种Cd污染土壤中,水铝钙石均能够增加土壤pH,降低Cd、Pb和Zn的有效态含量,其中Cd有效态含量最大降幅分别为97. 7%、96. 3%和91. 8%.水铝钙石促使高Cd污染土壤中Cd、Pb和Zn的可交换态转化成活性低的碳酸盐结合态、铁锰氧化态和残渣态,高Cd污染土壤的钝化效果优于中低污染土壤.水铝钙石的吸附作用、层间离子交换作用以及表面羟基和羧基等活性官能团的配位反应,在很大程度上降低了土壤重金属的生物有效性.因此,水铝钙石可有效应用于Cd、Pb、Zn等重金属污染农田的钝化修复.     

添加堆肥和赤泥对土壤生物有效性Cd和Zn的影响

采用土壤培养实验,研究添加堆肥和赤泥对土壤中Zn和Cd生物有效性的影响。结果表明,单独添加堆肥或赤泥以及赤泥和堆肥一起添加到土壤,均可以降低土壤中的交换态Cd和Zn含量以及生物有效态Zn和Cd含量。与对照相比,培养1-3个月后,单独添加堆肥、单独添加赤泥和同时添加赤泥与堆肥导致土壤交换态Cd含量分别降低14%-18%、33.3%-46.1%和44.2%-57.7%;土壤交换态Zn含量分别降低54.4%-59%、100%和100%;土壤生物有效态Cd含量分别降低11.8%-14.7%、25.1%-33.7%和32.6%-43.9%;土壤生物有效态Zn含量分别降低14.1%-15.8%、59.7%-72.2%和43.2%-58.4%。     

用分级方法评估土壤对重金属的缓冲能力

研究了不同Cd,Zn,Cu和Pb负荷对5种土壤(油黄泥土、棕红壤、红壤、石砂土和紫砂土)中的重金属形态的影响,分析了不同土壤对重金属的缓冲作用及其影响因素.结果表明,未污染土壤中的重金属主要以残余态为主,占土壤重金属总量的51%以上.随着土壤重金属负荷的提高,土壤中交换态重金属的比例增大,残余态比例下降,有效性提高,对重金属的缓冲作用下降.由于Cd,Zn,Cu和Pb本身的特性不同,土壤中各组分与Cd,Zn,Cu和Pb的结合方式及程度不同.当外源重金属进入土壤后,土壤对重金属的缓冲性为:Pb>Cu>Zn Cd,酸性土壤和砂质土壤的缓冲能力较低.当重金属加入量较低时,重金属优先向氧化物结合态和有机质结合态转化;而当加入量较高时,向交换态和碳酸盐结合态转化的比例增加.土壤pH下降可使交换态Cd,Zn,Cu和Pb的比例递增,降低土壤对重金属的缓冲性,增加了重金属对环境影响的风险.      

Aging effect on the mobility and bioavailability of copper in soil

Aging effect on the mobility and bioavailability of copper (Cu) was investigated using a spiked soil with different incubation periods from 3 to 56 d. Wheat was planted and earthworm was cultured separately in the incubated soils. The mobility of Cu in soil was evaluated by a chemical fractionation scheme and the toxicity and bioavailability were assessed by measuring the biomass and Cu concentration in tissues. Results showed that aging had a significant effect on Cu fraction distribution, of which Cu tended to incorporate from the exchangeable into more stable fractions such as the reducible and oxidisable fractions. However, aging had little effect on Cu bioavailability to wheat and earthworms. Comparing the soil being incubated for 3 d and 56 d, Cu concentration in wheat roots decreased from 14.5 to 12.8 mg/kg, and no significant changes in Cu concentration were observed in both wheat shoots and earthworms. The Cu concentration was around 2.0 and 50 mg/kg for wheat shoots and earthworms, respectively, irrespective of soil incubation time. The CaCl2-extractable Cu had a linear relationship with Cu concentration in wheat roots (R2 = 0.65, P < 0.05), but no linear relationship can be found for wheat shoots and earthworms. Biological control may be more crucial for Cu accumulation in organism than the changes in soil Cu fraction caused by aging.     

铁锰双金属材料对砷和重金属复合污染土壤的稳定化研究

由于矿产资源的共生、伴生现象及历史上采选冶技术的相对落后,我国矿区附近的重金属污染场地多存在复合污染的情况,而稳定化技术是解决该问题的有效措施.本文通过室内模拟培养实验和静态吸附试验,研究了人工合成的铁锰双金属材料(FMBO)对矿区复合污染土壤中As、Pb、Cd等重金属的稳定化作用和机制.毒性浸出实验结果表明,在3种不同的As和重金属复合污染土壤中,FMBO材料能够对As和Pb等重金属起到较好的稳定化作用,在5%的最大添加量下,FMBO对As、Pb的稳定化效率分别能够达到95.2%~100%和95.5%~97.5%,同时不会引起Cd、Zn和Cu等重金属的活化.由连续提取实验结果可知,FMBO能够使土壤中As和Pb由酸可提取态向可还原态转变,稳定性增强.微观特征分析结果表明,FMBO材料对As的稳定化主要通过表面羟基(—OH)基团的吸附作用,而对Pb、Cd等金属离子则通过吸附、沉淀等多种方式起作用.总体看来,FMBO材料适用于As、Pb等重金属复合污染土壤的治理.     

Risk assessment of heavy metal contaminated soil in the vicinity of a lead/zinc mine

Heavy metal contamination of soils through anthropogenic activities is a widespread and serious problem confronting scientists and regulators throughout the world. In this study we investigated the distribution, chemical species and availability of lead, zinc, cadmium and copper in nine surface（0 to 20 cm） soils from near an abandoned lead/zinc mine tailings located in Shaoxing, Zhejiang, China. Total heavy metal contents ranged from 5271 to 16369 mg/kg for Pb, 387 to 1221 mg/kg for Zn, 3.0 to 9.3 mg/kg for Cd and 65 to 206 mg/kg for Cu. In general, all heavy metals exceeded China National Standards for Soil Environmental Quality of Heavy Metals by a factor of 3-65 times. Comparison of the heavy metal concentrations（Pb, Zn, Cd and Cu） with clay content revealed a strongly significant relationship while significant relationship（ P 〈 0.001 ） was also obtained between Cd ＋ Zn and Pb ＋ Cu. Solid phase speciation of the soils using Tessier procedure showed that the heavy metals were distributed in the order： residual 〉〉 organically complexed-Fe-Mn oxides occluded 〉 carbonate bound 〉 exchangeable 〉 water soluble. In the organic matter fraction, the ratio of Pb（29.1% ） to its total concentration in the soils was higher than those of Zn（4.70% ）, Cd（3.16% ） and Cu（9.50% ）. The percentages of the water soluble and the exchangeable fractions of Pb（1.80% ） and Cd（2.74% ） were markedly greater than those of Zn（0.10% ） and Cu（0.15% ）, suggesting that Pb and Cd are relatively more mobile and hence more toxic in the contaminated soils. Strongly significant relationships between H20-Pb, H20-Zn and H20-Cu, strong positive correlations between H20-Pb, H20-Zn, H20-Cu and organic matter in soil were found. The content of H20-Pb, H20-Zn, H20-Cu was negatively correlated with pH values. The similar negative relationships between pH values and exchangeable heavy metals were also recorded. It is suggested that increasing soil pH or liming the soil could decrease bioavailability of heavy metals in the soil.     

氧化木糖无色杆菌(Achromobacte rxylosoxidans)LAX2对Cu、Pb和Cd复合污染土壤的生物矿化修复研究

我国土壤重金属复合污染较为突出,是目前亟待解决的土壤环境问题之一.本文研究了一株氧化木糖无色杆菌LAX2对Cu、Pb和Cd共存体系的生物矿化作用及其复合污染土壤的矿化修复作用.结果表明,菌株LAX2的发酵液、无菌发酵液和菌体细胞对3种重金属的去除能力大小顺序均为Pb~(2+)Cd~(2+)Cu~(2+).X-射线衍射、扫描电镜、红外光谱和能谱分析表明,3种重金属共存时菌株LAX2发酵液可诱导形成PbCO_3和CdCO_3晶体,而Cu不能单独成矿,混合矿物晶体呈长杆状.菌株LAX2发酵液能够明显降低黑钙土和白浆土中Cu、Pb和Cd的有效态含量,矿化修复30 d后,黑钙土中Cu、Pb、Cd的有效态含量分别降低了48.0%、71.4%、62.8%,白浆土中Cu、Pb、Cd的有效态含量分别降低了42.0%、63.2%、53.6%;碳酸盐结合态和铁锰氧化物结合态含量明显增加,可交换态和有机物结合态含量明显降低.矿化修复后的土壤中重金属的浸出毒性随修复时间的增长而降低,黑钙土中Cu、Pb、Cd浸出量分别降低了90.3%、93.2%、92.8%,白浆土中Cu、Pb、Cd浸出量分别降低了82.5%、86.1%、84.3%.以上结果说明,菌株LAX2可通过碳酸盐矿化作用固定土壤中的复合重金属,且在相同条件下对黑钙土的修复效果好于白浆土.     

Mobility and speciation of Cd,Cu,and Zn in two acidic soils affected by simulated acid rain

Through a batch experiment, the mobility and speciation of heavy metals(Cd, Cu, Zn) in two acidic forest soils from Hunan Province were studied. The results showed that the release and potential active speciation of Cd, Cu, and Zn in the tested contaminated red soil(CRS) and yellow red soil(CYRS) increased significantly with pH decreasing and ion concentrations increasing of simulated acid rain, and these effects were mainly decided by the pH value of simulated acid rain. Cd had the highest potential nsk on the environment compared with Cu and Zn. Cd existed mainly in exchangeable form in residual CRS and CYRS, Cu in organically bound and Mn-oxide occluded forms, and Zn in mineral forms due to the high background values.     

影响土壤重金属生物毒性的若干因子

本文应用发光细菌法探讨了土壤类型、粘土矿物、无定形金属氧化物、吸附剂对重金属纯溶液以及重金属污染土壤的降毒效应.红壤、砖红壤对Cu、Cd、Pb呈现负的降毒效应,而对As具有明显的降毒作用.黑土、黄棕壤对供试阳离子金属具有明显的降毒效应,对As降毒却不明显.试验证明粘土矿物及其组成是影响土壤重金属毒性的最基本因素.无定形氧化锰对供试阳离子金属的降毒能力大于无定形氧化铁,对As的效应二者则相反.不同吸附剂对Cu、Cd、Pb呈现基本相同的降毒顺序,即炉烟灰>活性炭>泥炭>干活性污泥,不同配比吸附剂对红壤添加性阳离子和东乡铜矿污染土壤均具有明显的降毒作用.添加吸附剂的东乡铜矿污染土壤随着土壤溶液毒性的消除,随之也消除或减轻了其对水稻种芽的急性毒害.     

无机钝化剂对镉污染酸性水稻土的修复效果及其机制

以浙江南部重金属镉（Cd）轻度污染酸性稻田为对象,以当地应用最广泛的3种无机钝化剂（硅钙镁钾肥、钙镁磷肥和石灰）为材料,通过田间试验研究了不同用量（750、1500和2250 kg ·hm^-2）钝化剂阻控土壤酸化与稻米Cd积累的效果与化学机制.结果表明,3种钝化剂可有效地改良土壤酸化和降低水稻稻米Cd积累,施用2250 kg ·hm^-2硅钙镁钾肥、钙镁磷肥和石灰分别增加土壤pH值0.62、0.65和0.86单位,减少交换性酸总量67%、69%和78%,降低糙米镉含量73%、68%和77%.施用2250 kg ·hm²钝化剂可使Cd轻度污染稻田上种植水稻糙米中ω（Cd）低于0.2 mg ·kg^-1,达到国家食品安全标准;与对照比较,3种钝化剂均显著降低土壤中DTPA提取有效态镉含量,降低弱酸提取态（F1）和可还原态（F2） Cd含量,增加残渣态（F4） Cd含量;相关分析表明糙米Cd含量与土壤pH与交换性阳离子含量呈显著负相关,与DTPA-Cd、F1-Cd、F2-Cd和交换铝含量呈显著正相关.应用最小二乘路径模型分析了糙米Cd含量、Cd有效性和化学形态与土壤性质的关系,土壤交换性阳离子对糙米Cd含量、有效镉和水稻产量直接影响的路径系数分别为-0.566、-0.866和0.873,土壤pH主要通过直接影响有效镉而间接影响糙米镉含量.田间试验证明,这3种钝化剂是实现镉污染酸性水稻土水稻安全生产的有效技术,它们主要通过影响土壤交换性阳离子而直接影响土壤镉生物有效性,进而影响糙米中镉的积累,研究结果可为受污染耕地水稻安全生产和酸化土壤改良提供科学依据.     

Ammonia volatilization and availability of Cu, Zn induced by applications of urea with and without coating in soils

Ammonia volatilization and the distribution of Cu and Zn were investigated in two types of soil treated with coated and uncoated urea. The rate of ammonia volatilization in two weeks after fertilizing with coated urea was 8% in soil 1 (soil derived from river alluvial deposits in Dongting Lake Plain) and 5.15% in soil 2 (red soil derived from quaternary red clay), about half the rates observed when fertilizing with common urea, implying that the hydrolysis speed of the coated urea was lower than for common urea, and that the coated urea can increase nitrogen use efficacy. As for the availability of Cu and Zn, their concentrations decreased in the first week after fertilization, and then increased, which was contrary to the effect of treatment on soil pH. For example, when the pH was 7.99, there was 0.79 mg/kg exchangeable Cu and 0.85 mg/kg exchangeable Zn in the soil derived from river alluvial deposits in Dongting Lake Plain. However, the concentrations of exchangeable Cu and Zn were generally lower for the common urea treatments than those with the coated urea because the peak pH for the common urea treatment was greater. The concentrations of these elements correlated well with pH in the range 4-8 in second order polynomial fits.     

长株潭典型污染区稻田剖面土壤重金属的累积及形态特征

为探究长株潭地区不同污染源影响下稻田土壤中重金属的分布特征,对该区有机肥施用区、沼液灌溉区、铅锌矿污染区以及工业污染区剖面土壤中重金属的总量和形态进行分析,采用单项污染指数和综合污染指数进行风险评价,并利用已知污染源区的土壤重金属形态特征对未知污染源区的土壤进行污染源解析. 结果表明:①研究区表层(0~10 cm)土壤中Cd、Pb、Cu、Zn、Cr和Ni的平均含量分别为0.8、54.5、43.6、158.6、106.2和23.3 mg/kg. 相对于长株潭地区土壤背景值,表层土壤中Cd、Pb和Zn均有累积,且Cd平均含量超过《土壤环境质量 农用地土壤污染风险管控标准(试行)》(GB 15618—2018)中农用地土壤污染风险筛选值;随着土壤深度增加,Cd、Pb、Zn和Cr在次表层(10~20 cm)土壤也有累积,其平均含量分别比当地背景值高出6.9%、19.8%、101.4%和67.0%;在深层(80~100 cm)土壤中,Zn和Cr的平均含量仍分别比当地背景值高出30.4%和48.4%. ② Cd、Pb的单项污染指数高值集中在表层土壤,部分采样点呈轻微或轻度累积,少数采样点呈中度累积;Zn以轻微累积和中度累积为主,极少数采样点为重度累积,个别采样点存在污染风险;综合污染指数显示,研究区内表层土壤为重度或中度累积. ③有机肥施用区TOC含量与可氧化态Cu、Zn含量呈显著或极显著相关;沼液灌溉区TOC含量则与可氧化态Cu、Zn含量均呈极显著相关;铅锌矿污染区可交换态Pb含量与可交换态Cd、Zn含量均呈极显著相关;而工业污染区则只有可交换态Pb含量与可交换态Cd含量呈极显著相关. 研究显示,污染源的不同造成长株潭地区稻田土壤中不同重金属的累积程度及其主要赋存形态间的相关性存在明显差异,因此,可以借助土壤中重金属的累积程度、主要赋存形态及其相关性对土壤中重金属的主要来源进行初步识别,为源头防治污染土壤提供理论依据.      

西南地区典型土壤酸化特征及其与重金属形态活性的耦合关系

采用空间代替时间的方法,采集了西南地区主要类型和不同酸化阶段的土壤样品,分析了土壤理化性质特征、酸缓冲性能和重金属赋存形态,结合小白菜盆栽生物试验,探讨土壤酸化和重金属形态活性变化的耦合关系.结果表明,紫色土和黄壤随着土壤酸化程度增加,土壤交换性盐基离子降低,由交换性Ca²⁺流失引起.不同酸化阶段紫色土和黄壤对酸敏感性差异较大,紫色土在pH>7.50和pH<4.50时,酸缓冲容量较大;黄壤酸缓冲容量和土壤交换性盐基离子含量呈较强的相关性,且随着酸添加量增加,酸缓冲容量的增大倍数和土壤盐基离子消耗速率有关.重金属Cd和Pb在土壤中的赋存形态和土壤类型、酸化程度紧密相关,紫色土与黄壤中Cd和Pb主要以可交换态和残渣态为主,且随土壤酸化程度增加交换态占比增加,残渣态占比减少;红壤中以残渣态和Fe-Mn结合态为主,Cd的Fe-Mn结合态分别是紫色土和黄壤的2.15倍和1.73倍,Pb的Fe-Mn结合态是紫色土与黄壤的4.30倍和3.91倍,与红壤铁含量较高有关.盆栽试验表明土壤酸化一定程度上抑制小白菜的生长量,酸化严重的黄壤(pH<5.70)中小白菜生物...     

两株耐铅镉真菌对土壤中铅镉赋存形态及小白菜吸收积累的影响

通过土培试验,研究接种耐铅镉真菌(产黄头孢霉Cephalosporium chrysogenum和头孢霉Cephalosporium SP.)对灭菌和未灭菌铅镉污染土壤上小白菜生长及铅镉赋存形态的影响.试验结果表明:接种两种耐重金属真菌可以降低或显著降低土壤中交换态铅镉、碳酸盐结合态铅镉和铁锰结合态铅镉,且显著增加土壤中有机结合态铅镉,因此降低了土壤中铅镉的活性;在灭菌和未灭菌铅镉污染土壤上接种两种真菌均能增加或显著增加小白菜的株高和鲜重,其中在未灭土壤中接种产黄头孢霉20 mL小白菜鲜重和株高最大,分别达到6.00 cm和3.22 g·株~(-1),在灭菌土壤上接种产黄头胞霉10 m L小白菜株高和鲜重最大,分别为10.66 cm和11.07 g·株~(-1);接种两种真菌可以显著降低未灭菌土壤上小白菜体内铅镉含量和累积量,在灭菌土壤上接种10 mL产黄头孢霉可以显著降低小白菜铅含量和累积量.     

河南省典型工业区周边农田土壤重金属分布特征及风险评价

为深入探讨典型工业区周边农田土壤重金属分布的特征,以河南省新乡市凤泉区大块镇工业区周边农田土壤为研究对象,对表面和剖面方向上土壤As、Cd、Cr、Cu、Ni、Pb和Zn等7种重金属污染的空间分布和污染风险进行分析,并使用主成分分析进行污染源解析,为该类工业区周边农田重金属污染治理与防控提供理论基础.结果表明,该工业区内...     

几种矿物材料对污染土壤中铜形态的影响

采用室内模拟培养的试验方法,以膨润土、硅藻土、磷矿粉及其改性产物、高炉铁渣、钢渣作为改良材料,探讨了几种材料对铜污染土壤的修复效果及存在的规律.同时,对欧共体标准物质局提出的三步提取法（简称BCR法）进行了适当改进,以改进的BCR法提取并分析各形态铜在土壤中的变化.结果表明,除磷矿粉外,其他材料（膨润土、硅藻土）的改性...     

改良剂对土壤铜镉有效性和微生物群落结构的影响

以一次性添加木炭、石灰和磷灰石稳定化修复4年后的土壤为研究对象,探讨了土壤中铜镉有效性和土壤微生物群落结构的变化.结果表明,3种改良剂的添加提高了土壤pH值,降低了土壤交换性酸和交换性铝的含量,使铜镉由活性态向非活性态和潜在活性态转化,其中磷灰石和石灰的处理效果优于木炭处理; Biolog测试发现,培养192h,木炭、石灰和磷灰石处理土壤AWCD值(0.61、0.76和0.70)分别是对照的1.33、1.65和1.52倍;且Shannon和McIntosh指数均较对照有所提高,表现为:石灰 > 磷灰石 > 木炭,表明改良剂处理后增加了土壤微生物对碳源的利用能力,提高了其功能多样性.PCR-DGGE分析结果显示,改良剂处理后土壤细菌优势群的数量显著增加,木炭、石灰和磷灰石处理Shannon指数分别比对照提高了0.22、0.39和0.24.相关性分析表明,土壤酸度和重金属有效性是影响稳定化修复重金属污染土壤细菌结构多样性差异的主要因素.