Floristic contamination of suburban forests near the city of Ivanovo

In the course of floristic studies in suburban forests near the city of Ivanovo, 206 species of vascular plants have been recorded, including 39 invasive species (18.9%). Information on specific features of distribution and activity of introduced species growing feral and accidental weeds in different forest types is presented. The most aggressive species are distinguished. Factors responsible for the invasion of alien species to forest cenoses and main tendencies in their dynamics are discussed.     

An assessment of heavy-metal contamination in surface sediments of the Suez Gulf using geoaccumulation indexes and statistical analysis

An assessment of marine pollution due to metals was made in the Suez Gulf based on surface costal sediment collected from 18 locations along the Gulf. The samples were dried and acid-digested, and the metal contents (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were determined using a flame atomic absorption spectrophotometer (air-acetylene) with deuterium background correction. An evaluation of the heavy-metal pollution status of the Gulf was carried out using enrichment factors (EF) and geo-accumulation Indexes (I_geo). Also, heavy-metal concentrations in Suez Gulf sediments were evaluated using the Effect Range-Low (ERL) and the Effect Range-Median (ERM). The results of a Spearman correlation and factor and cluster analysis of the heavy metals analysed in the collected sediment were discussed. The main source of contamination is offshore oil field and industrial wastes, which arise due to the ineffective and inefficient operation equipments, illegal discharge and lack of supervision, and prosecution of offenders.     

Germination,Growth, and Nodulation of Sesbania rostrata Grown in Pb/Zn Mine Tailings

Sesbania rostrata in pure and amended Pb/Zn tailings. About 90% of seeds of S. rostrata germinated in pure Pb/Zn tailings, which contained high concentrations of Pb, Zn, Cu, and Cd. Although seedling growth suffered from the adverse environment of Pb/Zn tailings, they became established on tailings stands, in the greenhouse, as well as on the actual tailings dam, and completed their life cycle in 4 months. Dry matter production and nitrogen accumulation was 3200 kg/ha and 69.4 kg/ha, respectively in the actual tailings dam. Applying inorganic fertilizer to Pb/Zn tailings led to no obvious improvement in growth and nodulation of S. rostrata, while tailings amended by river sediment or domestic refuse rich in organic matter improved the growth and nodulation of the species. Azorhizobium caulinodans survived and formed N-fixing stem and root nodules in S. rostrata grown in pure Pb/Zn tailings with a nodule biomass exceeding 300 mg fresh matter per plant.     

Comparative study of heavy metal distribution in some coastal seaweeds of Alexandria, Egypt

The distribution of Cd, Cu, Fe, Hg, Mn, Ni, Pb, and Zn concentration in five algae species (Enteromorpha intestinalis, Enteromorpha linza, Ulva lactuca, Corallina mediterranea, Pterocladia capillacea) collected from three areas having different types of metal contamination along Alexandria coastal waters (Egypt) were determined by Atomic Absorption Spectrometry. The recovery study was carried out using a Certified Reference Material TORT-2. The obtained heavy metal contents indicate that different species demonstrate various degree of metal accumulation. Enteromorpha intestinalis (green algae) recorded the highest levels of Fe and Mn while Corallina mediterranea (Calcareous red algae) recorded the highest concentration of Pb, Ni, and Cd in the three areas under study. According to the present study, filamentous algae (Enteromorpha intestinalis) showed the ability to concentrate greater amount of trace elements than the foliaceous ones (Enteromorpha linza). In each area, mercury concentration has nearly the same value for all species under study.     

某有色冶炼厂周围农业土壤中镉污染因素探讨

运用动力学原理和投入产出法则研究了浙江省某铅锌冶炼厂周围农业土壤中镉的污染因素。得出猪栏肥等有机肥是污染土壤的关键因子。提出了不搞稻草还田，而是采用养殖蚯蚓和种植蕨类植物的方法，以达到控制镉污染和净化土壤的目的。     

两种消化方法对无齿相手蟹重金属含量测定结果的影响

生物样品分别经湿灰法和干灰法消化处理后，测定其Zn,Cu和Pb的含量。结果表明，不同消化方法对样品中Cu含量的测定没有显著的影响，而对Zn和Pb含量的测定都有显著的影响，湿灰法处理后样品中Zn和Pb含量的测定值均普遍高于干灰法处理后相应的测定值。根据本研究结果可知。测定Cu含量的生物样品可用常规灰化温度进行处理，而测定Zn和Pb含量的生物样品宜用低温灰化技术进行处理。图6表1参12     

重金属元素在樟树人工林中的累积与迁移

结合樟树人工林生态系统生物产量研究,采用Hp3510原子吸收分光光度法测定樟树人工林生态系统不同组分中Cu、Zn、Mn、Pd、Ni、Cd的含量,探讨了重金属元素Cu、Zn、Mn、Pb、Ni、Cd在湖南株洲市樟树人工林中的累积与迁移.结果表明,樟树人工林地土壤层(0～100 cm)中,6种重金属元素的平均含量以Pb为最高,为67.929 mg/kg,Cd最低,仅为0.699 mg/kg,排序为Pb＞Zn＞Mn＞Ni＞Cu＞Cd,总储量为2 737 174 kg/hm2.在樟树不同器官中,Cu、Zn、Mn、Pd、Ni、Cd的含量范围分别为6.849～13.178 mg/kg,3.776～37.443 mg/kg,32.214～659.130 mg/kg,1.626～15.544 mg/kg,0.218～3.719 mg/kg,1.033～9.506 mg/kg.樟树对土壤中6种重金属元素富集能力排序为Cd＞Mn＞Zn＞Cu＞Pb＞Ni.在樟树林中,6种重金属元素的总积累量为11.124 kg/hm2,且排序为Mn(8.097 kg/hm2)＞Zn(1.429 kg/hm2)＞Cu(0.763 kg/hm2)＞Pb(0.491 kg/hm2)＞ Cd(0.272 kg/hm2)＞Ni(0.072 kg/hm2),重金属元素积累量空间分布为叶(3.447 kg/hm2)＞枝(2.863 kg/hm2)＞皮(1.685 kg/hm2)＞干(1.635 kg/hm2)＞根(1.307 kg/hm2).樟树林与环境之间,Mn的交换能力最强,其次是Cd、Zn、Cu,再次为Ni、Pb.     

淮河上游全新世黄土-土壤剖面重金属元素分布与环境变化

在野外考察研究的基础上利用X-射线荧光光谱仪测定了河南禹州全新世YPC黄土-土壤剖面Zn、Cu、Co、Ni、Nb、Pb、V、Cr、Mn、Ti重金属元素的含量及其变化,研究表明在黄土堆积期,重金属元素的含量都很低,变化幅度也很小,可作为衡量古土壤层成壤改造的背景值.在全新世古土壤和现代表土中这些元素含量却大大增加,说明在温暖湿润的时期,成壤改造使易溶易迁移元素的淋失导致重金属元素的相对富集.而Pb含量从8cm深度处向上急剧增加,增幅达60%,这是大气污染物沉降积累的客观记录.     

Arsenic contamination in the Kanker district of central-east India: geology and health effects

This paper identifies newer areas of arsenic contamination in the District Kanker, which adjoins the District Rajnandgaon where high contamination has been reported earlier. A correlation with the mobile phase episodes of arsenic contamination has been identified, which further hinges on the complex geology of the area. Arsenic concentrations in both surface and groundwater, aquatic organisms (snail and water weeds) soil and vegetation of Kanker district and its adjoining area have been reported here. The region has been found to contain an elevated level of arsenic. All segments of the ecoysystem are contaminated with arsenic at varying degrees. The levels of arsenic vary constantly depending on the season and location. An analysis of groundwater from 89 locations in the Kanker district has shown high values of arsenic, iron and manganese (mean: 144, 914 and 371 μg L⁻¹, respectively). The surface water of the region shows elevated levels of arsenic, which is influenced by the geological mineralised zonation. The most prevalent species in the groundwater is As(III), whereas the surface water of the rivers shows a significant contamination with the As(V) species. The analysis shows a bio-concentration of the toxic metals arsenic, nickel, copper and chromium. Higher arsenic concentrations (groundwater concentrations greater than 50 μg L⁻¹) are associated with sedimentary deposits derived from volcanic rocks, hence mineral leaching appears to be the source of arsenic contamination. Higher levels of arsenic and manganese in the Kanker district have been found to cause impacts on the flora and fauna. A case study of episodic arsenical diarrhoea is presented.