藏中矿区重金属污染对土壤微生物学特性的影响

土壤微生物对土壤重金属污染反应敏感，是探讨矿区土壤重金属污染生态效应的有效指标之一。通过野外调查与采样和室内分析，研究了藏中矿区重金属污染对土壤蔗糖酶、脲酶、脱氢酶和酸性磷酸酶活性、微生物生物量C（MBC）、N（MBN）和P（MBP）、土壤基础呼吸、代谢商（qCO2）及可矿化N的影响。研究表明，矿区土壤重金属Cu、Zn、Pb、Cd全量和有效含量均高于对照土壤；随着矿区土壤重金属含量增加，土壤酶活性、微生物量C、N和P、可矿化N均逐渐降低，土壤基础呼吸和qCO2则逐渐升高；土壤重金属与土壤蔗糖酶活性、脲酶活性、脱氢酶活性、酸性磷酸酶活性、MBC、MBN、土壤基础呼吸、qCO2及可矿化N具有显著的线性相关；脱氢酶活性对土壤重金属污染最为敏感，表明脱氢酶活性可作为藏中矿区土壤环境质量变化的有效指标。     

不同施肥管理措施对土壤碳含量及基础呼吸的影响

连续7年试验研究了施用15t/hm2和7.5t/hm2有机肥(包括EM堆肥、EM鸡粪肥和传统堆肥)、化肥和对照处理对土壤碳含量与基础呼吸的影响,结果表明:随有机肥施用量的提高,土壤可溶性碳、总有机碳、微生物生物量碳和土壤的基础呼吸随之增加。施用化肥可一定程度提高土壤可溶性碳、总有机碳、微生物生物量碳和土壤的基础呼吸。不同施肥措施对土壤有机碳、微生物生物量碳和土壤基础呼吸的影响趋势为EM堆肥处理>传统堆肥处理>化肥处理>对照,施肥对土壤微生物代谢商的影响趋势为EM堆肥处理<传统堆肥处理<化肥处理<对照。土壤微生物生物量碳与可溶性碳、总有机碳及土壤基础呼吸之间呈极显著正相关。土壤微生物代谢商与土壤可溶性碳、总有机碳、微生物生物量碳及基础呼吸之间呈极显著负相关。     

重金属污染矿区复垦土壤微生物生物量及酶活性的研究

对铜矿废弃地复垦土壤微生物生物量及酶活性研究结果表明 ,与对照土壤相比 ,矿区复垦土壤微生物生物量C、N和P均有所降低 ,微生物商Cmic Corg可作为矿区重金属污染土壤微生物学敏感指标之一 ;酶活性变化与此相似 ,脲酶、脱氢酶和酸性磷酸酶与对照差异显著 ,其他则与对照差异明显 ,一定程度削弱了矿区土壤中C、N营养元素周转速率和能量循环     

龙须草生长对重金属污染土壤的影响

为了探明龙须草种植对重金属污染土壤的影响,利用盆栽培养试验研究某矿业废弃地污染土壤对龙须草生长的影响,分析了龙须草生长90d,180d,270d和360d时土壤营养成分、重金属镉铅含量、微生物生物量和酶活性等的变化,以不种植龙须草为对照。结果表明,随着龙须草的生长,土壤镉铅总量和有效态含量均呈下降趋势,生长1a后土壤镉铅的有效态含量分别下降了28%和15%,但与对照相比无显著差异。土壤营养成分、微生物生物量和酶活性呈上升趋势,且与对照差异显著。与试验前相比,龙须草生长组有机质含量提高了1.5倍,全氮、全磷、全钾、速效磷和速效钾含量分别上升了7.6%,3.1%,10.2%,11.4%和11.2%。土壤微生物生物量碳、氮、磷、土壤转化酶、脲酶、酸性磷酸酶和过氧化氢酶活性分别增加了0.9倍,1.1倍,3.0倍,1.1倍,0.4倍,0.3倍和0.5倍。各指标相关性分析表明,土壤营养成分、微生物生物量和酶活性之间呈正相关,而与重金属含量呈负相关。说明龙须草对重金属污染土壤有一定的修复作用,具有较大的应用潜力。     

重金属Cd、Zn、Cu和Pb复合污染对土壤生物活性的影响

通过野外土样采集及室内培养试验(25℃),研究了云南东川铜矿区土壤酶和微生物特征,以及模拟重金属Cd、Zn、Cu、Pb复合污染对土壤微生物和酶活性的影响。结果表明,矿区土壤(距矿口0~800 m)重金属污染严重,Pb、Cd、Zn、Cu全量和有效含量是对照土壤(距矿口10 000 m)的3.7~141.0倍和2.2~773.2倍;距矿口越近,土壤有机质、有效氮、有效磷和速效钾含量及土壤pH亦越低,土壤酶活性和土壤微生物数量、微生物生物量碳和氮受到的抑制程度也显著增强。与对照土壤相比,距矿口0~800 m的土壤蔗糖酶、脲酶、酸性磷酸酶、过氧化氢酶和脱氢酶活性分别降低25.5%~47.3%、22.6%~74.2%、30.9%~83.1%、16.7%~69.1%和34.6%~92.3%;细菌、放线菌和真菌数量分别较对照下降30.5%~80.1%、8.1%~49.9%和3.3%~8.3%。土壤酶中的酸性磷酸酶和过氧化氢酶,土壤微生物中的细菌对重金属污染较为敏感。恒温(25℃)培养试验中,低量的Cd、Zn、Cu、Pb复合污染刺激了土壤酶活性和细菌、真菌、放线菌、微生物生物量碳和氮的数量,但高量的Cu、Zn、Pb、Cd复合污染使土壤酶活性、细菌、真菌、放线菌、微生物生物量碳和氮均显著下降。重金属Cd、Zn、Cu、Pb之间存在着一定的协同或拮抗作用,Cd、Zn、Cu和Pb之间在微生物生物量碳和氮上表现出明显的协同效应,Pb与Cd、Zn、Cu对细菌数量的复合效应机制为拮抗效应,Cd、Zn、Cu和Pb对真菌数量和放线菌数量的复合效应机制表现为协同效应和拮抗效应并存。     

铅锌银尾矿区土壤微生物活性及其群落功能多样性研究

通过对浙江省天台铅锌银尾矿区土壤微生物活性指标以及微生物群落功能多样性研究 ,结果表明 ,尾矿污染区土壤几种重金属含量比非矿区土壤有明显的增加。尾矿区土壤微生物特征发生了显著的变化 ,微生物生物量和可培养细菌数量显著降低 ,但土壤基础呼吸和微生物代谢商 (qCO2 )值却明显升高。Bi olog测试结果显示 ,随着重金属污染程度的加剧其土壤微生物群落结构发生了相应变化 ,尾矿区土壤微生物群落代谢剖面 (AWCD)及群落丰富度、多样性指数均显著低于非矿区土壤 ,且供试土壤间均达极显著水平差异 (p <0 .0 1) ,表明尾矿区重金属污染引起了土壤微生物群落功能多样性的下降 ,减少了能利用有关碳源底物的微生物数量、降低了微生物对单一碳源底物的利用能力     

粤北铅锌矿区土壤生态系统微生物特征及其重金属含量

粤北大宝山金属矿产资源的开发给生态环境带来了严重危害。对该铅锌矿区土壤的微生物特征进行研究。结果表明:五节芒植物中的元素含量表现为Zn>Pb>Cu>Cd,Zn与土壤元素的相关性最为显著,其次为Pb。与对照土壤相比,矿区土壤的微生物基础呼吸作用增强,但微生物生物量却显著降低,微生物生理生态参数Cmic/Corg、qCO2值明显升高。随着矿区土壤的重金属含量增加,矿区(1#、2#)土壤的生化作用强度明显下降,生化作用表现为与土壤重金属含量呈显著负相关。与非矿区(6#)土壤相比,其中土壤氨化作用、硝化作用、固N作用和纤维素分解作用强度分别下降43.19%～70.01%,70.71%～92.02%,58.54%～87.76%和55.00%～79.60%。生化作用表现为与土壤中重金属含量呈显著负相关。土壤微生物活性下降是矿区土壤生态系统遭受破坏的重要标志之一,也是矿区土壤微生物生态演变的重要因素之一。土壤微生物活性降低削弱了矿区土壤中C、N营养元素的循环速率和能量流动。     

生物炭对铜矿区污染土壤微生物活性及香根草富集铜、镉、铅的影响

矿区土壤易发生重金属污染,是土地资源利用和维护的一大难题。以铜矿区污染土壤为研究对象,按质量比添加0,1%,2%,4%,10% (w/w)的生物炭,进行香根草室内盆栽试验。研究添加生物炭对土壤pH和微生物活性、香根草富集与转运重金属的影响,探明重金属形态含量与生物炭、微生物活性的相关性,旨在为生物炭与香根草联合修复矿区重金属污染土壤提供理论参考。结果表明:生物炭的添加能提高土壤pH,显著提高土壤FDA水解酶、蔗糖酶和脲酶活性,显著促进土壤基础呼吸,但对土壤微生物量碳无显著影响;生物炭的添加使香根草生物量显著增大,降低土壤Cu和Pb的有效态占比,Cd的变化与此相反;添加生物炭促进香根草对Cd和Pb的富集,降低香根草对Cu的富集,减少Cu、Cd和Pb在香根草体内的转运,因此香根草可作为Cu、Cd和Pb的稳定化植物。土壤蔗糖酶活性与香根草叶片Cu、Cd和Pb含量、有效态和残渣态Cu含量呈显著正相关,土壤基础呼吸与叶片Cu、Cd和Pb含量、有效态Cu、Pb含量呈显著负相关,而与有效态Cd含量呈显著正相关。总之,生物炭可减弱矿区土壤重金属对香根草生长的毒害作用,并促进香根草对重金属的富集,两者结合可改善铜矿区污染土壤的理化性质和微生物活性,有利于重金属污染土壤修复,改善土壤质量。     

南方几种水稻土重金属污染下的土壤呼吸及微生物学效应

采集南方几种重金属污染下的水稻土，通过室内培养的方法研究土壤CO2排放的动态变化以及微生物学指标的差异。结果表明，在60d的培养期内，前7d土壤呼吸速率较高，占了整个排放量的30．89％～64．37％，并且这一阶段重金属对土壤呼吸速率的影响最大。重金属对土壤微生物生物量的影响表现出增加、抑制与无显著性差异的结果，而重金属对微生物熵及微生物代谢熵（qCO2）的影响却是极显著的，同时表现出增加与降低的不同结果。这说明土壤呼吸以及不同的微生物学指标，在长期的复合重金属污染条件下，其表现并不一致，微生物熵与代谢熵用于基本性质差异较大的土壤时，对重金属的响应更为灵敏。此外，土壤重金属的累积还能提高土壤中有机碳的含量。     

铅镉、石油污染和黑麦草种植对土壤微生物活性的影响差异

矿产和石油的生产与使用导致不同程度的土壤重金属和石油污染,已影响到人类健康与安全,土壤污染修复迫在眉睫。本研究采用室内盆栽试验的方法,在铅镉污染、石油污染土壤中种植黑麦草(Lolium perenne),探究土壤基础呼吸(SBR)、微生物生物量碳(MBC)及相关土壤酶活性的变化,揭示铅镉、石油污染对土壤微生物的影响,进而为重金属及石油污染土壤修复及其环境评价提供理论依据。共设置6个处理:未污染土壤(S),未污染土壤+黑麦草(SG),铅镉污染土壤(SH),铅镉污染土壤+黑麦草(SHG),石油污染土壤(SP),石油污染土壤+黑麦草(SPG)。研究发现:与处理S相比,在本研究铅镉及石油污染水平下,处理SH的SBR、MBC、过氧化氢酶活性和脲酶活性分别显著降低22.42%、44.90%、6.35%和44.88%(P 0.05);处理SP的SBR、MBC、脲酶活性和脱氢酶活性分别增加23.06%、52.04%、42.26%和65.37%(P 0.05);处理SG的MBC和过氧化氢酶活性分别降低60.54%和4.55%(P 0.05),SBR和脱氢酶活性分别增加31.51%和94.86%(P 0.05)。土壤受污染后,种植黑麦草处理的SBR和MBC、过氧化氢酶活性、脲酶活性高于对应未种植黑麦草的处理。这一结果表明,在一定含量范围内重金属污染抑制土壤微生物活性,而石油污染初期抑制、后期可以提升微生物活性,种植黑麦草在后期可显著增强污染土壤的微生物活性、提高土壤微生物生物量。     

长期重金属胁迫下的土壤微生物特征: 沈阳张士污灌区的案例研究

Soil samples were collected from Zhangshi Wastewater Irrigation Area in the suburb of Shenyang City, China, an area with a 30-year irrigation history with heavy metal-containing wastewater. The chemical properties and microbial characteristics of the soils were examined to evaluate the present situation of heavy metal pollution and to assess the soil microbial characteristics under long-term heavy metal stress. In light of the National Environmental Quality Standards of China, the soil in the test area was heavily polluted by Cd and to a lesser degree by Zn and Cu, even though wastewater irrigation ceased in 1993. Soil metabolic quotient （qCO2） had a significant positive correlation, while soil microbial quotient （qM） had a negative correlation with content of soil heavy metals. Soil microbial biomass carbon （MBC） had significantly negative correlation with Cd, but soil substrate~induced respiration （SIR）, dehydrogenase activity （DHA）, cellulase activity, and culturable microbial populations had no persistent correlations with soil heavy metal content. Soil nutrients, except for phosphorous, showed positive effects on soil microbial characteristics, which to a certain degree obscured the adverse effects of soil heavy metals. Soil Cd contributed more to the soil microbial characteristics, but qM and qCO2 were more sensitive and showed persistent responses to heavy metals stress. It could be concluded that qM and qCO2 can be used as bioindicators of heavy metal pollution in soils.     

铜矿尾矿库土壤—海洲香薷(Elsholtzia harchowensis)植物体系的微生物特征研究

对浙江哩铺铜矿尾矿库土壤—海洲香薷 (Elsholtziaharchowensis)植物体系的微生物特征进行了研究。结果表明 :海洲香薷植物中的元素含量表现为Cu >Zn >Pb >Cd ,Cu与土壤元素的相关性最为显著 ,其次为Zn。与对照土壤相比 ,矿区土壤的微生物基础呼吸作用增强 ,但微生物生物量却显著降低 ,微生物生理生态参数Cmic/Corg、qCO2 值明显升高。Biolog结果显示 ,矿区土壤微生物的群落结构发生改变 ,对能源碳的消耗量和速度显著升高 ,但利用效率却明显降低     

Response of microbial characteristics to heavy metal pollution of mining soils in central Tibet,China

Soil microbial activity plays a crucial role in soil microbiological processes, which can be used as a useful indicator to determine the ecological effects of heavy metal pollution on soils. The objective was to determine the effects of heavy metal pollution on mining soils at the Lawu mine of central Tibet, China on soil enzyme activities (sucrase, urease and acid phosphatase), microbial biomass C, N and P (MBC, MBN, and MBP), basal respiration, metabolic quotients, and N mineralization. Sixteen soil samples around the mine were sampled, and one soil sample, 2 km from the mine center, was taken as the control. Compared to the control, mining soils were polluted by heavy metals, Cu, Zn, Pb and Cd, resulting in decreases of sucrase activities, urease activities, acid phosphatase activities, MBC, MBN, MBP, and N mineralization, and increases of basal respiration and qCO₂. Multivariate analysis (cluster analysis [CA], principle component analysis [PCA] and canonical correlation analysis [CCA]) indicated nine microbial variables were only reduced to one principal component explaining 72% of the original variances, and MBC (R² = 0.93) had the highest positive loadings on the principal component. Mining soils polluted by heavy metals were perfectly clustered into four groups, which were highly distinguished by MBC. There were significant canonical correlations between soil heavy metals and microbial indexes on two canonical variates (R1 = 0.99, p < 0.001; R2 = 0.97, p < 0.01), which further demonstrated significant correlations between soil heavy metal contents and microbial characteristics. Hence, our results suggested that MBC may be used a sensitive indicator for assessing changes in soil environmental quality in metal mine of central Tibet.     

Effect of Clay Minerals on Immobilization of Heavy Metals and Microbial Activity in a Sewage Sludge-Contaminated Soil (8 pp)

Background   Aims, and Scope. Reducing heavy metal solubility and bioavailability in contaminated area without removing them from the soil is one of the common practices in decreasing the negative impacts on the environment and improving the soil quality. Therefore, our aim was to study the effect of clay minerals: Na-bentonite, Ca-bentonite, and zeolite applied to a contaminated soil on immobilization of heavy metals, as well as on some soil parameters related with microbial activity. Methods   A soil derived from sewage sludge was incubated with clay minerals of either Na-bentonite, Ca-bentonite, or zeolite for 111 days (d). During the incubation experiment, concentrations of water soluble Zn, Cd, Cu, and Ni were measured after extraction of 2 g air-dry soil with 50 ml of H2O for 2 h. After the water extraction, the soil sediment was extracted with 50 ml of 1 M NH4NO3 for 2 h to estimate the exchangeable amounts of heavy metals. Furthermore, soil microbial respiration, microbial biomass C, Corg mineralization, metabolic quotient (qCO2), and inorganic N were also investigated. Results and Discussion   Water extractable and exchangeable forms of heavy metals were changed by incubation and addition of clay minerals. Incubation of soil without addition of clay minerals (control) increased water extractable Cu by 12, 24 and 3.8% of initial content after 21, 62, and 111 d of incubation, respectively. The water extractable Zn decreased by 9% during 62 d of incubation and it tended to increase by 14% at the end of the incubation, as compared with the initial soil. Water extractable Cd decreased by 71, 66 and 33% of initial content, and Ni decreased by 54, 70, and 58%, after 21, 62, and 111 d of incubation, respectively. During the incubation experiment, the exchangeable form of all tested metals was decreased by incubation. The addition of clay minerals led to a significant decrease in water soluble and exchangeable forms of heavy metals during the incubation experiment, resulting in low metal extractability. The reduction in metal extractability was greater due to the addition of Na-bentonite or Ca-bentonite than that due to the addition of zeolite. During the first 3 weeks after addition of clay minerals, the studied biological parameters were not affected. However, as incubation progressed, the addition of Na- or Ca- bentonite led to a significant increase in soil respiration, microbial biomass C, Corg mineralization, and inorganic N; and a significant decrease in qCO2. This result is explained by sorption of heavy metals on Na-bentonite and Ca-bentonite and strong reduction of their toxicity. Conclusions   Our results clearly show that the addition of clay minerals, especially of Na-bentonite and Ca-bentonite, decreased the extractability of four metals during incubation. The decreased metal extractability was accompanied by an increase of soil respiration, Corg mineralization, microbial biomass C, and inorganic N and a decrease of metabolic quotient (qCO2), showing positive effect of clay mineral addition on soil biological parameters. Recommendations and Outlook   The use of Na-bentonite and Ca-bentonite is promising tool for reduction the extractability and possible toxicity of heavy metals in sewage sludge-contaminated soil. Therefore, the soils polluted with heavy metals may be ameliorated by addition of clay minerals, especially Na-bentonite and Ca-bentonite.     

不同相伴阴离子对镉污染红壤的微生物活性影响

通过外加醋酸镉和氯化镉的室内培养试验研究了相伴阴离子对镉污染红壤微生物活性的影响。结果表明 ,在相同镉浓度下相伴OAc- 对镉污染红壤的微生物生物量碳、基础呼吸和代谢商以及脲酶和酸性磷酸酶活性的抑制作用大于相伴Cl- ,统计分析显示 ,镉相伴OAc- 与Cl- 除对红黄泥的代谢商未达明显影响外 ,对供试红壤的其它微生物活性指标均达到显著差异 (p <0 0 5 )。用醋酸镉处理的土壤有效态镉含量明显高于氯化镉处理。钾盐试验结果表明 ,相伴OAc- 与Cl- 对土壤微生物活性没有产生明显抑制作用 ,OAc- 甚至还存在一定的刺激效应。可见 ,相伴OAc- 对镉污染红壤的微生物毒害作用大于相伴Cl- ,其直接原因可能是用醋酸镉处理的生物有效性镉明显高于氯化镉处理所致。     

不同植被群落下喀斯特土壤养分及生物化学性质特征

为了探讨植被群落对喀斯特土壤养分和生物化学性质的影响,对贵州茂兰国家级自然保护区不同植被群落下土壤养分、基础呼吸、微生物量碳及酶活性进行比较研究。结果表明:不同植被群落之间土壤养分含量差异显著,土壤总有机碳、全氮、全磷、碱解氮和有效磷表现为裸露地<草丛<灌丛≤乔林;土壤基础呼吸表现为裸露地<灌丛<乔林<草丛,诱导微生物量碳为裸露地<灌丛<草丛=乔林,而熏蒸微生物量碳为裸露地<草丛<灌丛<乔林;不同植被群落下土壤蔗糖酶活性高于裸露地,但不同植被群落间差异不显著,土壤脲酶活性有着裸露地<草丛=灌丛<乔林的趋势,而土壤碱性磷酸酶活性表现为裸露地<灌丛<乔林<草丛;土壤呼吸商和诱导微生物量与熏蒸微生物量比值均表现为乔林=灌丛<草丛=裸露地。结果分析表明,不同植被群落下喀斯特土壤养分水平及其凋落物差异影响着土壤微生物群落结构及活性,而土壤微生物执行着土壤营养元素生物化学过程,其群落结构和活性又影响着土壤养分水平及养分有效性。