植物原位阻截铅锌矿区土壤重金属效果和配置模式研究

为了研究铅锌矿区植物原位阻截土壤废渣重金属效果和配置模式,采用多种植物栽培和径流小区收集水样测定的方法,3年生植物的研究结果表明：苎麻、苦楝、构树可降低废弃尾沙坝地表径流水中重金属Pb负荷输出9.04%~9.64%。栾树、构树、芦苇、苦楝、刺槐可降低地表径流水中重金属Cd负荷输出67.0%~75.86%,构树、高羊茅、刺槐、栾树、芦苇、狗牙根、五节芒可降低地表径流水中重金属Cu负荷输出52.64%~70.97%,刺槐、女贞可降低地表径流水中重金属Zn负荷输出74.99%~78.35%;在重金属污染林地,刺槐可降低地表径流水中重金属Pb负荷输出40.96%,苦楝可降低地表径流水中重金属Cd负荷输出60.42%。构树通过植物富集,可以使铅锌尾矿区尾沙中Pb、Cd、As、Zn的含量分别降低31.87%、41.28%、29.48%、38.45%;女贞可以使铅锌尾矿区尾沙中Pb、Cd、As、Zn的含量分别降低27.31%、39.52%、33.47%、27.59%。植物原位阻截和修复重金属机理一是植物富集了土壤中重金属,二是植物使土壤中重金属形态发生了变化,这种机理有待进一步研究。     

不同饵料对3种西藏鱼类仔鱼生长及存活的影响

研究了卤虫无节幼体、专用仔鱼料、鳗鱼仔鱼料等3种不同饵料对西藏尖裸鲤(Oxygymnocypris stewartii)、异齿裂腹鱼(Schizothorax o'connori Lloyd)、拉萨裂腹鱼(Schizothorax waltoni Regan)等3种鱼类仔鱼生长和存活的影响。实验尖裸鲤、异齿裂腹鱼、拉萨裂腹鱼仔鱼的初始全长分别为(13.29±0.52)mm、(12.29±0.44)mm、(15.81±0.50)mm,实验周期分别为25 d、25 d、15 d。结果表明:与其他饵料组相比,投喂专用仔鱼料组,异齿裂腹鱼仔鱼和拉萨裂腹鱼仔鱼的平均全长、全长增加倍数以及存活率均高于其他各组,并有显著差异;尖裸鲤仔鱼的平均全长和全长增长倍数也高于其他各组,但存活率较投喂卤虫无节幼体低,并有显著差异。     

不同建植技术对露天煤矿排土场生态修复效果的影响及评价

为解决矿区排土场生态修复难和生态修复成本高的问题,提出了一种新的穴铺建植技术对排土场进行生态修复,并于2012—2015年期间选择4种建植技术对永顺煤炭有限公司矿区排土场开展生态修复工作。基于修复后（2015年）的植被生长状况和土壤改良效果,并通过对比分析的手段,对不同建植技术的生态修复效果进行了评价。结果表明:穴铺植生袋建植法（A）、旱梯田坡面建植法（B）、旱坡植生袋建植法（C）和沙柳围护建植法（D）4种不同建植技术中,在植被覆盖度方面表现为A（85%） > C（80%） > B（73%） > D（63%） > E（7%,裸地）;土壤容重方面表现为A（1.21 g/cm³） < C（1.27 g/cm³） < B（1.31 g/cm³） < D（1.43 g/cm³） < E（1.52 g/cm³）;土壤侵蚀模数方面表现为A[3 630 t/（km²·a）] < C[6 350 t/（km²·a）] < B[7 860 t/（km²·a）] < D[15 730 t/（km²·a）] < E[26 000 t/（km²·a）],均表明A技术在植被生长状况和土壤质地改良方面效果显著,有效解决了试验区人工建植植物群落稳定性差和水土流失量大等问题,成功完成了试验区的生态修复。穴铺植生袋建植技术在矿区排土场或类似区域的生态修复工程实践中具有良好的借鉴和参考作用。     

大冶龙角山矿区农田土壤重金属形态分布及其来源

为研究大冶龙角山矿区某溪流段沿岸农田土壤基本理化性质和重金属分布情况,采用Tessier五步连续提取法提取并测定土壤中Mn、Cu、Zn、Pb、Cr、Ni和Cd 7种重金属的形态与含量,并分析了重金属含量与土壤Fe和S含量之间的相关性。结果表明:所有重金属在大部分取样点总含量均超出湖北省土壤背景值;Cu和Cd总含量超过土壤环境质量三级标准(GB 15618—1995)限值,Zn、Pb、Cr和Ni符合土壤环境质量二级标准;Mn、Cu、Zn、Pb、Ni和Cd均以残渣态和铁锰氧化物结合态为主,Pb、Cr和Cd存在一定比例的可交换态。矿山矿石组分主要为黄铁矿和黄铜矿,且Mn、Cu、Zn、Pb和Cd的铁锰氧化物结合态、残渣态以及总含量的分布均与土壤Fe和S含量分布表现出较好的正相关关系,表明硫化物矿物开采引发了重金属Mn、Cu、Pb、Zn和Cd在该矿区农田土壤中的累积与污染。     

抗重金属植物根际细菌的植物促生长特征以及它们对黑芥种子萌发的影响

Phytoremediation is an emerging technology that uses plants and their associated microbes to clean up pollutants from the soil, water, and air. In order to select the plant growth-promoting rhizobacteria(PGPR) for phytoremediation of heavy metal contamination, 60 bacterial strains were isolated from the rhizosphere of two endemic plants, Prosopis laevigata and Spharealcea angustifolia, in a heavy metal-contaminated zone in Mexico. These rhizobacterial strains were characterized for the growth at different pH and salinity, extracellular enzyme production, solubilization of phosphate, heavy metal resistance, and plant growth-promoting(PGP) traits, including production of siderophores and indol-3-acetic acid(IAA). Overall, the obtained rhizobacteria presented multiple PGP traits. These rhizobacteria were also resistant to high levels of heavy metals(including As as a metalloid)(up to 480 mmol L(-1)As(V), 24 mmol L(-1)Pb(Ⅱ), 21 mmol L(-1)Cu(Ⅱ), and 4.5 mmol L(-1)Zn(Ⅱ)). Seven rhizobacterial strains with the best PGP traits were identified as members of Alcaligenes, Bacillus, Curtobacterium, and Microbacterium, and were selected for further bioassay.The inoculation of Brassica nigra seeds with Microbacterium sp. CE3R2, Microbacterium sp. NE1R5, Curtobacterium sp. NM1R1,and Microbacterium sp. NM3E9 facilitated the root development; they significantly improved the B. nigra seed germination and root growth in the presence of heavy metals such as 2.2 mmol L(-1)Zn(Ⅱ). The rhizobacterial strains isolated in the present study had the potential to be used as efficient bioinoculants in phytorremediation of soils contaminated with multiple heavy metals.     

土壤重金属污染背景下的任豆修复试验

为寻找适合矿业尾矿坝人工生态恢复的植物,以广西南丹长坡矿堆存50a之久的尾矿坝为背景,通过盆栽模拟,运用室内土培和水培两种试验方法,研究了不同矿土比例(尾矿样与泥土比例分别为5∶0、4∶1、3∶2、2∶3、1∶4、0∶5)以及不同浓度(0、2.5、5、10、25、50、100、150、200、250mg·L-1)Pb2+、Cu2+、Zn2+在任豆苗体内的吸收、积累和分布的动态变化规律。结果表明,任豆对Pb、Cu、Zn都具有一定的吸收能力,任豆幼苗可以在一定的重金属胁迫环境下存活,任豆对重金属Pb的耐性最大,在高浓度下依然可以存活。任豆对不同类型的重金属的吸收及转运能力存在较大差异,从任豆对Pb、Cu、Zn的转运能力来看,任豆并非这3种重金属的超累积植物。试验表明,任豆在矿业尾矿坝的人工生态恢复(植物修复)中有一定的应用价值,但能否大规模采用任豆作为尾矿坝的生态修复物种,尚需进一步研究验证。     

河北省石灰岩矿区自然生态环境特征探究

基于石灰岩矿区先天脆弱的自然环境,石灰岩矿区开采带来的生态问题趋于严峻。作者通过对河北省石灰岩矿区分布区域的自然生态环境进行分析,得出不同地域的石灰岩矿区生态环境特征,从而为石灰岩矿区后期的生态恢复与治理工程提供基础性资料。     

海南昌化铅锌矿废弃地重金属污染评价及其空间分布特征

通过对海南昌化铅锌矿废弃地采集的56份土壤样品进行分析,并对其重金属含量进行测定,采用内梅罗污染指数法与潜在生态风险指数法进行污染评价,运用克里金插值法进行空间分布分析。结果表明,废弃地重金属镉(Cd)污染程度最高,铅(Pb)与锌(Zn)次之,均超过国家三级标准值;从内梅罗综合指数来看,废弃地土壤重金属污染达到重度污染级别;从生态风险角度分析,废弃地重金属潜在生态风险达到重度风险级别;从克里金插值结果来看,废弃地表层土壤污染最小的地方均在废弃地东北部地区以及西南部河流尾段处,而污染最严重的地方集中在尾矿库东部、服务区、居民点、河流中段以及河流转弯处。     

Ethylenediurea (EDU) effects on hybrid larch saplings exposed to ambient or elevated ozone over three growing seasons

Ground-level ozone (O3) pollution is a persis-tent environmental issue that can lead to adverse effects on trees and wood production,thus indicating a need for forestry interventions to mediate O3 effects.We treated hybrid larch (Larix gmelinii var.japonica × L.kaempferi)saplings grown in nutrient-poor soils with 0 or 400 mg L-1 water solutions of the antiozonant ethylenediurea(EDU0,EDU400) and exposed them to ambient O3 (AOZ;08:00-18:00 ≈ 30 nmol mol-1) or elevated O3 (EOZ;08:00-18:00≈ 60 nmol mo1-1) over three growing sea-sons.We found that EDU400 protected saplings against most effects of EOZ,which included extensive visible foliar injury,premature senescence,decreased photosyn-thetic pigment contents and altered balance between pig-ments,suppressed gas exchange and biomass production,and impaired leaf litter decay.While EOZ had limited effects on plant growth (suppressed stem diameter),it decreased the total number of buds per plant,an effect that was not observed in the first growing season.These results indicate that responses to EOZ might have implications to plant competitiveness,in the long term,as a result of decreased potential for vegetative growth.However,when buds were standardized per unit of branches biomass,EOZ significantly increased the number of buds per unit of biomass,suggest-ing a potentially increased investment to bud development,in an effort to enhance growth potential and competitiveness in the next growing season.EDU400 minimized most of these effects of EOZ,significantly enhancing plant health under O3-induced stress.The effect of EDU was attributed mainly to a biochemical mode of action.Therefore,hybrid larch,which is superior to its parents,can be significantly improved by EDU under long-term elevated O3 exposure,providing a perspective for enhancing afforestation practices.     

Characterization of the Soil Organic Matter in Agricultural Mine Spoils and Reclaimed Soils Treated with Organic Amendments

Recycling organic waste in agricultural soils is a valid solution. We performed short‐term experiments to investigate the fate of urban sludge and composts, in mine spoils, cultivated or uncultivated, and reclaimed soils located in Florence and Milan, Italy. The samples, either treated or untreated, were fractionated by density into light (<1.63 Mg m^?3) and heavy (>1.63 Mg m^?3) fractions. The fractions were analyzed for total carbon (C) and nitrogen (N) contents and for δ ¹³C and δ ¹⁵N isotopes, and they were characterized by ¹³C NMR spectroscopy. Treatment increased the heavy fraction. The addition of sludge in the Florence area acts in synergy with the cultivation, increasing the light fraction (LF). In the Milan area, the LF tends to be decomposed and apparently transformed into HF. The addition of amendments or cultivation enhances the decomposition with release of carbon dioxide. For future research, we suggest lengthening the time of the experiments to integrate climatic variations.