基于“3S”技术的辽宁省某尾矿库扩容工程生态影响预测与评价

以辽宁省某尾矿库为例,基于GIS技术,利用2010年的TM遥感影像及地形图,预测该尾矿库扩容后的生态影响。分析结果显示:尾矿库扩容工程对生态的影响主要体现在土地利用、植被、生态景观和地形地貌的变化4个方面。     

大豆秸秆生物炭对铅锌尾矿污染土壤的修复作用

采用盆栽空心菜的方法,研究了大豆桔杆生物炭对铅锌尾矿污染土壤的修复作用。污染土壤中Cu、Zn、Pb和Cd含量分别为50,400,1 119,3.4mg/kg。结果表明:土壤无论是否受到铅锌尾矿污染,添加3%生物炭(w/w)均能显著提高土壤pH;3%生物炭能够抑制铅锌尾矿污染导致的土壤pH降低。大豆桔杆生物炭对尾矿污染土壤和未污染土壤中重金属有效态的影响不同,与未污染土壤相比,3%生物炭的钝化作用不能抵消铅锌尾矿污染导致的重金属有效态含量的增加。铅锌尾矿污染抑制空心菜生长;施加3%生物炭可以消除铅锌尾矿污染对空心菜生长的抑制作用。生物炭显著降低污染土壤空心菜根部重金属含量,而对地上部分的影响,不同元素表现出不同的特点;3%生物炭能够阻控铅锌尾矿污染土壤中Cu、Zn、Pb和Cd向空心菜地上部迁移富集。大豆桔杆生物炭对空心菜吸收重金属的影响,在铅锌尾矿污染土壤和未污染土壤上表现不同,存在元素之间的拮抗作用以及由于生物炭提高空心菜生物量所产生的稀释作用。在研究设置条件下,与未污染土壤相比,从空心菜生物量和可食部分吸收重金属含量来评价,施加3%大豆桔杆生物炭可以修复铅锌尾矿导致的土壤污染。     

遮荫处理对铁尾矿基质臭柏实生苗快速叶绿素荧光特性的影响

【目的】通过比较分析铁尾矿基质下不同遮荫处理间臭柏实生苗叶片原初光化学反应的差异,揭示臭柏在不同光照条件下的光保护机制,从理论上解释其天然更新过程,为臭柏光胁迫的研究提供理论依据,也为臭柏在铁尾矿废弃地造林提供技术依据。【方法】以唐山迁安铁尾矿为基质,通过盆栽遮荫试验,利用快速叶绿荧光诱导动力学测定与 JIP-test数据分析方法,分别测定0,25%,50%,75%和90%5个遮荫处理下臭柏叶绿素8项荧光参数。【结果】1)全光照条件下Fo 增大,Fm 减小,而叶片光合系统量子产额和能量分配比率(φPo,Ψo和φEo)、单位面积光合机构的比活性参数(Fm,ETo/CSm和 TRo/CSm)和单位面积内反应中心的数量(RC/CSm)均最小,且各个遮荫处理组间差异均达到显著(P＜0.05)或极显著水平(P＜0.01),表明全光照条件下臭柏实生苗反应中心失活,受到光抑制,而全光照下快速叶绿素荧光诱导动力学曲线中 K 点与 J 点明显高于其他遮荫处理,而且光抑制对臭柏叶片PSⅡ的供体侧(OEC)有伤害,造成PSⅡ受体侧(Q －A )的大量积累,阻碍电子传递链向Q －A 下游传递。2)全光照条件下叶片热耗散的量子比率(φDo )和单位面积光合机构的比活性参数( DIo/CSm )均最大,且与其他遮荫处理组间差异也均达到显著(P＜0.05)或极显著水平(P＜0.01),表明全光照条件下臭柏在遭受光抑制后,通过增加天线色素的热耗散,增加非辐射能量耗散等一系列机制来保护光合机构免受过量光能的危害。3)随着遮荫率增加,φPo ,Ψo和φEo,Fm(ABS/CSm),ETo/CSm和TRo/CSm,RC/CSm随之上升,而φDo和Fo(ABS/CSo),DIo/CSm随之下降,90%遮荫处理表现出明显的光捕捉特征,50%遮荫处理 Fm ,PIABS的平均值最大,说明该遮荫条件下臭柏叶片光抑制最小,光合能力最强,其他参数在不同遮荫处理组间无明显差异( P＜0.05)。【结论】臭柏幼苗若无遮荫措施,受到光胁迫,而其通过增加非辐射能量耗散途径达到光抑制防御的机制。因此臭柏天然更新从乌柳灌丛下开始,逐渐脱离乌柳灌丛的保护,完全暴露在全光照条件下,进而实现自身的不断生长、壮大,但在废弃地上植苗造林初期尚需采取一定的遮荫措施,以提高造林成活率。     

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.     

无害化污泥与钼尾矿配施对沙化潮土土壤质量的影响

以小麦-玉米轮作体系下的沙化潮土为研究对象,通过2012—2015年3年5季田间定位试验,选用经过无害化处理且符合国家相关标准的商业化污泥和钼尾矿产品,研究无害化污泥与钼尾矿施用对我国典型沙化潮土土壤质量指标的影响,为无害化污泥与钼尾矿资源化利用提供理论和技术依据。结果表明:45 t·hm~(-2)污泥(W3)与钼尾矿配施对沙化潮土有机质(SOM)的提升效果最明显,SOM在玉米季W3+75 t·hm~(-2)(M1)处理显著增加了165.10%,在小麦季W3+M2处理显著增加了106.10%(P0.05);相比单施同一水平污泥,污泥与75 t·hm~(-2)钼尾矿配施下土壤0.25 mm水稳性团聚体(WR0.25)含量,平均质量直径(MWD)和几何平均直径(GMD)分别显著升高了38.04%~60.24%,28.45%~45.27%和41.34%~67.77%(P0.05),对促进土壤形成水稳性团聚体以及提高水稳性团聚体稳定性的作用更为突出;45 t·hm~(-2)污泥与75 t·hm~(-2)钼尾矿配施对沙化潮土微生物量碳(SMBC)和微生物量氮(SMBN)提升效果最明显,在玉米季分别显著提高了235.52%和156.79%(P0.05),在小麦季分别显著提高了249.24%和128.32%(P0.05);单施污泥和污泥配施75 t·hm~(-2)钼尾矿处理土壤微生物量熵(q MB)在玉米季和小麦季分别显著提高了21.95%~46.25%和36.38%~71.17%(P0.05)。但污泥与高量钼尾矿配施,SMBC、SMBN和q MB较单施同一水平污泥和与75 t·hm~(-2)钼尾矿配施的处理在玉米季分别下降了3.89%~19.85%、4.31%~17.86%和6.95%~33.47%,在小麦季分别下降了5.34%~23.24%、4.33%~28.08%和3.09%~32.33%,表明钼尾矿高量施用时会降低微生物活性。由灰色关联度分析方法得出,45 t·hm~(-2)无害化污泥与75 t·hm~(-2)钼尾矿配施(W3+M1)能显著提高沙化潮土SOM、SMBC、SMBN和q MB,并提高土壤平均质量直径(MWD)和几何平均直径(GMD),有效改善沙化潮土质量,在3年5季试验期间也未发现土壤和作物籽粒受到重金属污染。同时,W3+M1处理显著提升了土壤肥力等级至Ⅰ级,在此基础上,可以酌情不再施用污泥和钼尾矿。     

贵州尾矿区野生豆科牧草根瘤菌及其抗性测定

为了筛选获得对复合重金属具有耐受能力且能在本地豆科植物根系内定殖共生的抗性根瘤菌,本研究从贵州省内的锰矿区、铅锌矿区采集野生豆科牧草根瘤样品,经分离纯化、菌体形态观察、16S rRNA基因序列比对分析,获得71个根瘤菌保存菌株。系统发育和区系分析结果表明,分离菌株分属7属28种,其中根瘤菌属(Rhizobium)的分布频率高达54.93%,为优势属,木兰根瘤菌(R.indigoferae)的分布频率最高(15.49%),为优势种。选择来自不同尾矿区、不同种类的根瘤菌17株,采用重金属平板法测定各供试菌株对贵州尾矿土分布较多的Pb²⁺,Zn²⁺,Cr⁶⁺,Mn²⁺,Cd²⁺五种重金属的耐受性,结果发现17个菌株对3种或3种以上的重金属都具有不同程度的耐受能力,其中HMZT039-6,HSST042-6,HSST042-1,ZHQT052-1和HXTT050-1对5种重金属离子均有耐受能力,为筛选出的最优抗性根瘤菌株。本研究结果可为本地区土壤重金属污染的修复治理提供共生微生物资源。     

Changes in Cd,Cu, Ni,Pb and Zn Fractionation and Liberation Due to Mussel Shell Amendment on a Mine Soil

Mining activities are related to relevant environmental pollution issues that should be controlled. We used sequential extractions to fractionate Cd, Cu, Ni, Pb and Zn retained on unamended or mussel shell‐amended mine soil samples, all of them treated with a mixture of the five heavy metals (total metal concentration of 1·57 mmol L⁻¹), after 1, 7 and 30 days of incubation. In addition, we used the stirred flow chamber technique to study the release of each of the five heavy metals from these different unamended and shell‐amended soil samples. The results indicate that the shell amendment caused a decrease in the most soluble fraction, while increasing the most recalcitrant (least mobile) fraction. With equivalent implications, the stirred flow chamber experiments showed that mussel shell amendment was associated to a decrease in heavy metal release and increased retention. The highest mussel shell dose and incubation time caused the most relevant changes in pH values and thus in metal retention, also indicating the importance of pH modifications in the mechanism of retention acting in the amended samples. In view of these results, the use of mussel shell amendment can be encouraged to increase heavy metal retention in acid mine soils, in order to minimise risks of environmental pollution. Copyright © 2016 John Wiley & Sons, Ltd.     

Revegetation of copper mine tailings with ryegrass and willow

To restore vegetation on metal mine tailings is very difficult because they often contain high concentrations of heavy metals, low nutrient content and low water retention capacity. This study involved 3 experiments that evaluated the effects of 4 treatment amendments: montmorillonite, rice straw, organic manure and chemical fertilizer on the growth of ryegrass (Loliurn perenne L.) and willow (Salix virninalis L.) with Cu and Zn mine tailings from two mining areas. The results showed that ryegrass was the most tolerant of 4 crops to Cu toxicity. Also when organic manure, which contained high concentrations of inorganic salts, was added to the mine tailings, it significantly hindered ryegrass growth (P=0.05).Meanwhile, with ryegrass organic manure significantly increased (P=0.05) the extractable Cu concentration in both mine tallings. When montmorillonite was used as a mine tailings amendment with willow, the height and tress number at the 1st cut were significantly greater (P = 0.05) than a control without montmorillonite. However there was no significant difference for height, tress number, dry weight or root dry weight at the 2nd cut. So, amendment applications to reduce metal toxicity and increase nutrients retention in mine tailings were essential during revegetation of mine tailings.     

德兴铜矿尾矿库植被重建后的土壤肥力状况和重金属污染初探

德兴铜矿是我国的超大型铜矿,尾矿砂的排放是其主要的环境问题之一,目前主要堆积于尾矿库中。1号尾矿库于1986年服役期满后共堆积矿砂2.15×107 m3,面积约210 hm2。20世纪90年代后期,在坝坡约30 hm2覆有客土的地区进行了一系列植被重建的试验研究工作,本文报道了1998年开始在旱稻(OryzaLinn.)、花生(Arachis Linn.)、香根草(Vetiveria zizanioidesNash)和湿地松(Pinuselliottii Engelm.)等18种不同植被组合条件下的土壤基本农化性状(pH、有机质(OM)、铵态氮、速效P、速效K)以及0.05 mol L-1 HCl可提取态重金属在3~4年时间内的变化情况,结果表明,坝坡土壤N、P、K严重不足,且保水、保肥能力弱,需要不断地进行培肥和改良。三年多来,土壤pH总体上无显著变化;OM第三年有显著上升,约为第一年的127%;NH4 N成直线下降,第二年和第三年分别为第一年的72.9%和43.0%;随着耕作实践的推移,速效P和速效K显著上升,但仍旧处于较低水平。重金属(主要是Cu)污染严重,Cu、Zn、Pb、Cd在植物中有明显积累。研究结果强调了试验区在植被重建中不宜种植食用植物,以避免食物链的污染。     

植物修复对锰尾渣污染土壤特性的影响

采用盆栽法研究栽培美洲商陆和大豆进行植物修复后,锰尾渣污染土壤特性的变化。栽培美洲商陆和大豆可增加土壤的碱解氮、速效磷、速效钾和有机质。栽培植物后,土壤pH值变化不显著,但土壤磷酸酶、尿酶、蛋白酶、蔗糖酶、硝酸还原酶和脱氢酶的活性都高于对照。栽培植物可影响土壤锰和镉的形态分布,降低土壤锰和镉总含量,减少土壤水溶性锰和镉含量。在锰尾渣污染区域,混种美洲商陆与大豆进行植物修复,改良土壤特性更佳。