土壤的植物修复与超积累植物研究

被污染土壤的植物修复将是未来更好与更廉价的修复技术,所以近年来对植物修复与超积累植物的研究兴趣日益增加。本文简要介绍了近期的发展趋势。目前研究的重点包括根际土壤微环境中的复杂反应与吸收过程,金属从土壤向植物根以及从植物根向叶的传输过程,金属在超积累植物中的定位与螯合作用等等。这是分析化学与环境科学及植物科学交叉研究的新领域,充满挑战。     

铀污染土壤的植物修复研究

核工业的发展, 导致重金属铀的排放和扩散, 造成了地表土壤的污染, 对社会和环境造成了很大的影响, 如何修复被铀污染的土壤成为了一个难题, 近年发展起来的植物修复技术以其成本低廉、安全、环保的特点成为修复被铀污染的土壤的新选择. 寻找理想的超富集植物是这一技术的基础和关键之所在, 通过实验模拟铀污染土壤(土壤中铀的浓度为1.00×10² mg•kg^－1), 选取分属8种科目的19种植物去修复, 选出了几种对铀的修复性能较好的本土植物, 实验表明四季香油麦菜的生物累积系数(Bioconcentration factors, BFS)和生物转移系数(Translocation factors, TFS)都大于3, 且地上部分铀的富集浓度高达1.67×10³ mg•kg^－1, 可以作为铀的超富集植物, 四川沿阶草、四季豆、扁竹兰、吊兰几种本土植物对铀污染的土壤具有潜在的修复能力, 借助于基因工程、联合修复或添加土壤改良剂有望使其转变为对铀的超积累植物.     

重金属污染土壤植物修复的强化措施研究进展

植物修复是一种有着巨大市场潜力的治理重金属污染土壤的技术,由于影响植物修复效率的因素较多,至今实际应用还很少。针对目前植物修复技术的不足,主要从植物本身的性能、重金属的生物有效性以及农艺管理措施等三方面,综述了近年来国内外有关植物修复强化措施的研究进展,并展望了今后该领域的研究方向。     

土壤硒污染的生物修复技术

硒是一种较特殊的微量元素，人和动物缺硒和硒中毒之间的范围很窄，土壤硒污染能对当地的人和动物产生重大伤害。采用传统的土壤污染治理方法，成本高，效果差，而近年来兴起的生物修复技术是治理土壤硒污染的既有效又经济的方法。     

特选榨菜对铀污染土壤的修复评价

本文通过两种不同的加铀方式,加入不同种类及浓度的螯合剂,以及土壤改良剂(有机肥、微生物肥料、腐殖酸、尿素)的方法,研究了不同因素对特选榨菜修复铀污染土壤的影响。结果表明:在pH=5时把UO_2(NO_3)_2·6H_2O溶液喷洒入土壤,使土壤中铀污染浓度为100 mg·kg~(-1)时,特选榨菜地上部铀富集的浓度最大可以达到1103.42 mg·kg~(-1),根部为1909.49 mg·kg~(-1),去除率为7.81%;上述含铀土壤放置2年后制备成模拟铀污染的土壤,进而栽种特选榨菜进行修复,在100 mg·kg~(-1)铀污染浓度下,植物上部铀富集浓度最大为295.83 mg·kg~(-1),根部为268.42 mg·kg~(-1),年去除率为2.52%。用Tessier五步连续提取法测定两次修复土壤中铀的形态,发现模拟铀污染土壤比铀喷洒于土壤中有效态的铀(交换态和碳酸盐结合态)要低52.7%;加入柠檬酸、苹果酸等螯合剂以及有机肥、微生物肥料、腐殖酸、尿素等土壤改良剂,在模拟铀污染土壤修复时发现有机肥会降低植物上部对铀的富集;而柠檬酸和微生物肥会增强植物上部对铀的富集。     

生物修复放射性污染土壤的研究进展

核能的利用给人类带来了福利也带来了灾难。部分土壤被放射性物质污染,放射性物质通过食物链进入人体,威胁人类健康。目前各国科研工作者正在积极寻找可行的办法解决土壤的放射性污染问题,并发展起来许多方法来修复放射性污染的土壤。本文就放射性污染土壤的来源、危害、处理等进行综述,并重点介绍了生物修复放射性污染土壤的研究进展。     

污染土壤的物化修复治理技术研究

污染土壤的修复治理过程中,物化技术以其快速高效的特点成为国内外研究的热点。本文通过对工程措施、玻璃化技术、热修复、电动力修复、光化学降解、化学淋洗、化学固定/稳定化、化学氧化以及联合修复等常见土壤物化治理技术进行了分析,探讨了各种工艺技术的性能及优缺点,旨在为我国土壤污染修复治理技术的选择提供参考。     

重金属污染土壤修复技术研究进展

概述了土壤重金属污染的特点、现状及污染的来源,主要从工程措施、农业措施、改良措施和生物修复措施四方面对国内外各种修复技术进行分析与评论,指出各类措施的原理、优缺点、实用性。同时,提出了当前土壤重金属污染与修复技术研究的重点。     

污染土壤的物化修复治理技术

污染土壤的修复治理过程中,物化技术以其快速高效的特点成为国内外研究的热点。本文通过对工程措施、玻璃化技术、热修复、电动力修复、光化学降解、化学淋洗、化学固定/稳定化、化学氧化以及联合修复等常见土壤物化治理技术的分析,探讨了各种工艺技术的性能及优缺点,旨在为我国土壤污染修复治理技术的选择提供参考。     

成都市土壤-植物系统中镉的分布特征

对成都市蔬菜及根系土中镉含量数据进行了综合分析。结果发现,成都市土壤镉存在明显的区域分布规律;镉在莴笋体内主要分布在叶片部位;土壤和植物中镉的总量无显著相关关系,可为给城市的环境规划及治理提供科学依据。     

电感耦合等离子体质谱法测定土壤中镉和总汞

建立电感耦合等离子质谱法测定土壤中镉和总汞的方法。土壤样品在电热板上用盐酸和硝酸于100℃低温消解,重量法定容,取上清液上机测定。镉和总汞含量分别在0.502~10.20 ng/g,0.212~5.010 ng/g范围内线性良好,相关系数(r2)大于0.999,土壤中镉和总汞的检出限分别为0.021,0.002μg/g,测定结果的相对标准偏差分别为1.99%,5.57%(n=6),加标回收率分别为97.5%~101.1%,87.5%~92.9%。该方法样品处理简单快捷,检出限低,准确度和精密度高,适合土壤中镉和总汞含量的测定。     

土壤氟与植物

氟是人体必需微量元素,其丰缺与人体健康息息相关。土壤在地理环境中的特殊地位决定着土壤氟对生态环境的特殊意义。土壤氟(特别是土壤水溶性氟)与植物体的氟含量密切相关,从而也与人体健康密切相关。不同植物对氟的富集程度不同,蔬菜(特别是叶菜)对土壤氟的富集程度很高,是造成地氟病的重要因素。     

AAS Determination of Lead and Cadmium in Leaves Polluted by Vehicle Exhaust

Abstract

The determination of Pb and Cd in three different kinds of biological tissues, namely Sapindus mukorossis, Alstonia scholaris and Diospyros embryopteris collected from a national city park were carried out using atomic absorption spectrophotometry. The various tissues contain different concentrations of Pb and Cd. This phenomenon and changes in concentration with the distance to the sampling sites are discussed and compared with values reported in literature. Significant pollution is mainly due to vehicle exhaust.     

土壤中镉及镉的赋存形态研究进展

综述了土壤中镉及镉的赋存形态研究进展,包括:土壤环境中镉及其污染来源,土壤中镉的赋存形态,镉赋存状态同镉生物活性的关系,土壤性状对镉赋存形态的影响,土壤中镉的测定方法等。     

Prediction of Plant Contamination by Cadmium and Zinc Based on Soil Extraction Method and Contents in Seedlings

Abstract

Prediction of plant contamination on the basis of environmental conditions seems to be an important task. In order to assess the suitability of three soil extractants and seedlings as a prediction media for the content of Cd and Zn in mature plants, three independent pot trials were conducted. In these trials six soil types of different properties were used. The total number of pots was 160 (40 variants in 4 replicates). Soils were artificially contaminated by Cd and the selected variants also by Zn. The contents of Cd and Zn in soil extractants and seedlings were compared with the contents of these elements in corn mature plants (roots and stems) by means of regression analysis. For cadmium, the best results as to the prediction of its content in mature plants were obtained with NaNO₃, whereas for zinc the best results were given by the seedlings.     

土壤中镉对酸雨的敏感性研究

模拟土壤在自然酸雨淋洗条件下镉的释放行为,研究了不同酸度、不同酸雨成分、不同流量的酸雨对土样中镉淋出的影响,以及镉在不同碳酸根含量的土样对酸雨淋洗的敏感性。     

土壤中镉的污染及治理

阐述了土壤中的镉污染及其治理,包括:土壤中镉污染的来源以及对植物和人类的危害,同时介绍了土壤镉污染的检测和治理方法。     

Using Surfactant System to Wash a Polluted Soil by Petroleum Derivatives in Egyptian Abu Madi Fields in Terms of Emulsification

The exploration and production activities of the natural gas in Abu Madi region (in middle delta) progressed in the last decade. The condensate hydrocarbon and formation water are bi‐products produced during the natural gas industry. The accompanied water contains 10–15% condensate (gasoline). This water with gasoline was drained into the Shehab El‐Din drain. The farmers were used this water to irrigate their fields. Great areas of the fields were out of order of planting as the result of gasoline pollution. This work concentrates on washing the polluted soil using locally prepared surfactant (LABSA‐Na) in the washing process. The soil sample was picked up from the Abu Madi field and was divided into pots (four pots for each treatment). The experiment was designed on the basis of polluting the soil by gasoline (condensate) from 1 to 10%. The washing process was carried out in presence of 0.1, 0.3, and 0.5% surfactant solutions. The control and blank sample were taken in consideration. The washed and the latent oil percentages were determined using the spectrophotometric method. After polluting and washing the soil, the pots were fertilized and planted by Zea Mays. The pots were irrigated twice a week. The length of plants was followed up. The obtained results cleared that, the efficiency of washing process increases with increasing of the pollutant percentage and also with increasing of surfactant concentration. The maximum washed oil (gasoline) was obtained at 10% gasoline and 0.5% surfactant concentration. The length of plants after 21 days of planting were; 0 (no planting), 24, 34, 39, 54, and 57 cm against polluted soil and planted (control) washed soil by water only; washed soil by 0.1%; washed soil by 0.3%; washed soil by 0.5% and no polluted soil (blank) respectively. These data revealed that, removing the hydrocarbon from the soil by washing using surfactants is the most effective method as the result of solubilization and emulsification of the hydrocarbon by surfactant which make it more removable.     

改性活性炭对土壤镉的吸附性影响

目的研究3种改性活性炭对菜地、河流底泥、荷花底泥镉吸附性的影响。方法对活性炭进行酸改性、碱改性和氧化改性,采用双硫腙分光光度法测定镉含量。结果对实验土样,最佳活性炭添加量为0.025 g/g。随着初始镉含量的升高,土壤对镉的吸附量不断增大。结论 3种改性活性炭相比普通活性炭对湿地土壤的镉吸附量均有不同程度的提升,荷花底泥中,酸性、氧化改性活性炭相比普通活性炭,吸附效果提高7.7%,8.3%,吸附效果提升显著。