印度芥菜和香根草对Pb污染土壤的修复效能及作用途径

为探究印度芥菜(Brassica juncea)和香根草(Vetiveria zizanioides L.)对Pb污染土壤的修复效能和作用途径,采用Pb污染土壤〔w(Pb)为400~2 000 mg/kg〕进行为期30 d的盆栽试验,分析植物对Pb的耐受性、积累能力和固定效果.结果表明:① 印度芥菜和香根草对Pb的积累主要集中在根部,两种植物根部累积的w(Pb)分别为206.62~902.40和288.42~1 102.47 mg/kg,单株植物的Pb积累量分别为70.75~138.31和99.09~220.49 μg,香根草对Pb污染土壤的修复效能高于印度芥菜. ② 印度芥菜和香根草对Pb的去除率随土壤中w(Pb)的增加而降低,对Pb的固定率则随土壤中w(Pb)的增加而增加,二者对Pb的去除率最大值分别为1.02%和1.78%,对Pb的固定率可达11.22%和16.78%,两种植物对Pb污染土壤修复的主要途径为植物固定. ③ 主成分分析表明,w(脯氨酸)对植物Pb积累过程具有重要作用.研究显示,相比于印度芥菜,香根草更适用于Pb污染土壤的植物修复.      

Impact of organic manure on the phytoremediation potential of Vetiveria zizanioides in chromium-contaminated soil

Chromium is a pollutant present in electroplating waste water and its removal is necessary for the protection of the environment. Vetiveria zizanioides (VZ) was grown in chromium effluent concentrations of 50, 100 and 200 mg kg ^?1 soil amended with organic manure and the potential for phytoremediation was determined. The amounts of Cr in plant tissues (root and shoot), soil and percentage electrolyte leakage of VZ roots were analysed. From the results, VZ amended with organic manure showed the greatest potential for Cr removal because of its faster growth and larger biomass achieved over the whole length of the experiment. In this study, 92.25% Cr removal efficiency was obtained with a Cr concentration of 50 mg kg ^?1 soil and removal efficiencies of 90.5% and 85% were obtained with 100 and 200 mg kg^?1, respectively after a period of two months of VZ growth.     

利用香根草进行尾矿植被恢复初探

在分析了南京幕府山采矿尾渣的基本理化性质基础上,研究了香根草在不同矿渣上的适应性,及其对尾矿植被恢复的作用。结果表明,香根草有较强的适应性,在碳质页岩和白云石矿渣上均正常生长,干物产量高,能够有效改变尾矿的地表生态环境,加速植被恢复,是修复、治理采石尾矿的优良植物。     

An approach for restoration of the water quality with emphasis on the removal of organochlorine pesticides and eutrophic conditions in tropical rivers

This work deals with an approach for the water quality restoration with emphasis on the removal of organochlorine pesticides and eutrophic conditions in tropical rivers, causing influence on the management of the central-regional aqueduct, as a source of water supply for human consumption (4 million people) and industrial production in the states of Carabobo, Cojedes and Aragua, Venezuela, testing the phytoremediation techniques through Vetiveria zizanioides (VZ) species and coupled bioreactors, Sequencing Batch Reactor (SBR) followed by an Upflow Anaerobic Filter in Three Separate Stages (UAF-3SS). Five rivers are involved known as Chirgua, Paito Guacara, Ereigüe, and Tucutunemo, whose waters have been classified as hypereutrophic, and containing organochlorine pesticides (OCPs). As a sample, for Tucutunemo River, OCPs included to DDT (dichlorodiphenyltrichloroethane) and its isomers and DRINs (Aldrin, Endrin and Dieldrin) dissolved in water and sorbed on sediments, which were measured during the dry and rainy seasons in the period 2013 to 2016, in three monitoring stations distributed in a reach of 15 km. The results indicated that p.p′-DDT concentration dissolved in water was increased up to 10 times from rainy to dry seasons, indicating that a permanent use of it is being carried out by farmers in the agricultural activity development. Steady concentrations of the DTT isomers (e.g., p.p′-DDD and p.p′-DDE) and Aldrin isomers (e.g., Dieldrin) demonstrated that the anaerobic and aerobic biodegradation processes occurred along the river and between climatic seasons. At experimental scale, VZ hydroponic system developed over a period of 6 months for the removal of nutrients demonstrated moderately low to high removal efficiencies. With respect coupled bioreactors, each bioreactor has been experimentally tested, demonstrating satisfactory performance in Chemical Oxygen Demand (COD) removal from industrial wastewater containing recalcitrant and inhibitory substances (46%–98%), which was estimated in the influent ranging from 3500 to 5500 mg/L, evidencing that coupling of bioreactors might lead to a effluent COD complying with environmental regulations.     

Accumulation of heavy metals in four grasses grown on lead and zinc mine tailings

A field experiment was conducted to compare the growth and metal accumulation of Vetiveria zizanioides, Paspalum notatum, Cynodon dactylon and Imperata cylindraca var. major on the tailings, amended with 10 cm domestic refuse complex NPK fertilizer(Treatment A), 10 cm domestic refuse(Treatment B) and complex NPK fertilizer(Treatment C) respectively, and without any amendment used as control (Treatment D). The results indicated that V. zizanioides was a typical heavy metal excluder, because the concentrations in shoots of the plants were the lowest among the four plants tested. The most of metal accumulated in V. zizanioides distributed in its root, and transportation of metal in this plant from root to shoot was restricted. Therefore, V. zizanioides was more suitable for phytostabilization of toxic mined lands than P. notatum and C. dactylon, which accumulated a relatively high level of metals in their shoots and roots. It was also found that I. cylindraca var. major accumulated lower amounts of Pb, Zn and Cu than C. dactylon and P. notatum, and could also be considered for phytostaliUsaton of tailings. Although the metal(Pb, Zn and Cu) concentrations in shoots and roots of V. zizanioides were the lowest, the total amounts of heavy metals accumulated in shoots of V. zizanioides were the highest among the four tested plants due to the highest dry weight yield of it. The results indicated that V. zizanioides was the best choice among the four species used for phytoremediation (for both phytostabilization and phytoextraction) of metal contaminated soils.     

香根草等三种植物的抗盐性比较

盐度对香根草、百喜草和水花生３种草本植物生长发育的影响相当明显．植物体,尤其是茎叶内的Ｎａ＾＋和Ｃｌ＾－直接影响到植物的株高、分蘖数、叶面积、根长等生长指标,进而影响到生物量;但在盐胁迫下,生物量的下降幅度不及上述４个指标的降幅大,根系生物量的降幅又不及茎叶的降幅。叶片光合色素亦受Ｎａ＾＋或Ｃｌ＾－的影响。在盐度不高时,色素含量增加,盐度较高时,色素含量下降,但它的幅度远不及生物量的下降幅度大。     

渗滤液灌溉对香根草胁迫及抗氧化系统的影响

以香根草(Vetiveria zizanioids)和渗滤液循环出水为实验材料,比较了不同体积浓度渗滤液灌溉对香根草胁迫相关生理指标及抗氧化系统的影响.结果表明,与对照相比,小于35%浓度的渗滤液灌溉6个月降低了香根草叶片脯氨酸(Pro)含量和相对膜透性,提高了叶绿素、蛋白质、抗坏血酸(AsA)、还原型谷胱甘肽(GSH)含量和叶绿素a/b值,过氧化物酶(POD)和超氧化物岐化酶(SOD)被激活,丙二醛(MDA)含量被控制在较低的水平上,表明低浓度渗滤液灌溉有利于香根草生长.大于35%浓度的渗滤液灌溉,随浓度的增大,香根草叶绿素含量和a/b值明显降低,MDA、H₂O₂、Pro进一步积累,相对膜透性显著增加,AsA、GSH含量下降,SOD和POD活性受抑制,表明高浓度渗滤液灌溉会造成活性氧产生和抗氧化系统清除之间的失衡,导致膜脂过氧化作用加剧,会加重对香根草的胁迫.灌溉6个月较3个月相比,叶绿素含量下降,Pro、MDA积累,表明灌溉时间延长也会导致胁迫加重.     

312国道应用香根草治理滑坡的试验研究

312国道边坡上的试验表明,香根草适宜在南京地区公路边坡上运用,可以有效地防治坡面水土流失,固定表层土壤,而且随时间推移防止土壤流失的效果越来越明显,固土护坡效果总体上比较成功。但本地区春季移栽香根草时缓苗期过长,影响香根草在雨季到来时充分发挥作用。