Flame Atomic Absorption Spectrometry Determination of Trace Amounts of Cadmium and Zinc in Water Samples after Preconcentration onto Modified Amberlite XAD‐4 Resin     

Sayed Zia Mohammadi  Daryoush Afzali  Mohammad Ali Taher  Hedayat Darijani 《洁净——土壤、空气、水》2010,38(2):140-145

In the present article, a procedure for the simultaneous separation and preconcentration of trace amounts of cadmium and zinc is proposed. It is based on the adsorption of cadmium and zinc ions onto a column of Amberlite XAD‐4 resin loaded with aluminon reagent. Cadmium and zinc ions are quantitatively retained on the column in the pH range from 6.5–7.5, at a flow rate of 2 mL min^–1. The cadmium and zinc ions are eluted with 5.0 mL of 5 mol L^–1 HNO₃ solution. Cadmium and zinc are measured by flame atomic absorption spectrometry (FAAS). In the present case, 0.1 μg of cadmium and 0.5 μg of zinc can be concentrated in the column from 1000 mL of aqueous sample, where their concentrations are as low as 0.1 and 0.5 ng mL^–1, respectively. The relative standard deviations, for seven replicated determinations of 1.0 μg mL^–1 of cadmium and zinc, are 1.2 and 1.1%, respectively. The detection limits for cadmium and zinc in the original solution are 0.02 and 0.11 ng mL^–1, respectively. The interference of a large number of anions and cations has been studied and the optimized conditions are utilized for the determination of trace amounts of cadmium and zinc in different environmental and standard samples.  相似文献   

Efficiency of compost in the removal of heavy metals from the industrial wastewater     

Günay Kocasoy  Zeynep Güvener 《Environmental Geology》2009,57(2):291-296

Authorities have been applying very strict regulations for the treatment of industrial wastewater recently because of the threatening level of the environmental pollution faced. Industrial wastewater containing heavy metals is a threat to the public health because of the accumulation of the heavy metals in the aquatic life which is transferred to human bodies through the food chain. Therefore, recently, researchers have been oriented toward the practical use of adsorbents for the treatment of wastewater polluted by heavy metals. The aim of this research was to determine the retention capacity of compost for copper, zinc, nickel and chromium. For this purpose, experiments in batch-mixing reactors with initial metal concentrations ranging from 100 to 1,000 mg/l were carried. It was also observed that compost could repeatedly be used in metal sorption processes. The experiments conducted indicated that compost has high retention capacities for copper, zinc and nickel, but not for chromium. Thus, compost has been approved as a potential sorbent for copper, zinc and nickel and may find place in industrial applications. Thus, solid waste which is another source of significant environmental pollution will be reduced by being converted into a beneficial product compost.  相似文献   

Adsorption of Zinc using Tea Factory Waste: Kinetics,Equilibrium and Thermodynamics     

Kailas L. Wasewar  Mohammad Atif  Basheshwar Prasad  Indra Mani Mishra 《洁净——土壤、空气、水》2008,36(3):320-329

In India, the annual production of tea is ca. 857,000 tonnes, which is 27.4% of the total world production. The amount of tea factory waste (TFW) produced per annum after processing is ca. 190,400 tonnes. TFW can be used as a low cost adsorbent for the removal of toxic metals from the aqueous phase. An investigation was carried out to study the feasibility of the use of TFW as an adsorbent for the removal of the heavy metal, zinc. Equilibrium, kinetic and thermodynamic studies were reported. The straight line plot of log (q_e–q) versus time t for the adsorption of zinc shows the validity of the Lagergren equation. The various steps involved in adsorbate transport from the solution to the surface of the adsorbent particles were dealt with by using a Weber‐Morris plot, q_e versus t^0.5 for the TFW. The rate controlling parameters, k_id,1 and k_id,2, were determined and it was found that the macro‐pore diffusion rate was much larger than micro‐pore diffusion rate. A batch sorption model, which assumes the pseudo‐second‐order mechanism, was used to predict the rate constant of sorption, the equilibrium sorption capacity and the initial sorption rate with the effect of initial zinc (II) ion concentration. Equilibrium data obtained from the experiments were analyzed with various isotherms, i. e., Freundlich, Langmuir, Redlich‐Peterson and Tempkin. The adsorption equilibrium was reached in 30 min and the adsorption data fitted well to all models. The maximum adsorption capacity of TFW for zinc (II) ions was determined to be 14.2 mg/g. The capacity of adsorption on Zn(II) increased with increasing temperatures and pH. The maximum uptake level of zinc was observed at pH of 4.2. The various thermodynamic parameters, i. e., ΔG°, ΔH° and ΔS°, were estimated. The thermodynamics of the zinc ion/TFW system indicated a spontaneous, endothermic and random nature of the process. The results showed that the TFW, which has low economical value, is a suitable adsorbent for the removal of zinc (II) ions from aqueous solutions.  相似文献   

Land Use and Lake Sedimentation on the New England Tablelands of New South Wales,Australia     

R. J. HAWORTH  S. J. GALE  S. A. SHORT  H. HEIJNIS 《The Australian geographer》1999,30(1):51-73

Lead-210 methods have been used to establish a chronology of sedimentation extending back almost 80 years in Black Mountain Lagoon near Guyra on the New England Tablelands of north-eastern New South Wales, Australia. Estimates of the direct atmospheric fallout of unsupported ²¹⁰Pb and historical records of the pattern of phosphorus input to the lake provide support for the ²¹⁰Pb chronology. The sediments in the lake record an episode of disturbance which took place prior to c .1916, but after c .1790-1860. Since then, however, the site-specific rate of minerogenic sedimentation has been maintained at a relatively low and constant level of 0.93 kg m^-2 a^-1. [Note: the following symbols are used in this paper: a = year (annum), and d min^-1 g^-1 = radioactivity (spontaneous nuclear disintegrations per minute per gram of material).] This is despite major shifts in land use and intensification of agriculture, despite the occurrence of significant floods and droughts, and in the absence until recent times of the application of soil conservation practices. These rates may be contrasted with rates of 0.023 kg m^-2 a^-1 from the period 12.3-5.6 ka. These are at least an order of magnitude lower than those of the twentieth century. The lake sediments preserve evidence of the use of agricultural chemicals on the catchment during the twentieth century. These include phosphorus, zinc, arsenic and lead. Soils and sediments may act as long-term toxic stores for such chemicals, a problem often overlooked in rural areas.  相似文献   

营口—宽甸地区重力场特征及地质解释     

曹恩久 《国土资源》1991,(4)

营口—宽甸地区重力场自北而南有逐渐增高的总趋势。中部区重力低与重力高呈带状相间出现。结合该区已知的地质构造特征综合分析,重力负值带是早元古宙拗拉槽边界深断裂和构造—岩浆岩带的反映。隐伏、半隐伏花岗岩体的解释和推断,为逃一步寻找金、硼、铅锌等矿产提供了信息。  相似文献   

Baseline heavy metals and metalloid values in blood of loggerhead turtles (Caretta caretta) from Baja California Sur, Mexico     

Ley-Quiñónez C  Zavala-Norzagaray AA  Espinosa-Carreón TL  Peckham H  Marquez-Herrera C  Campos-Villegas L  Aguirre AA 《Marine pollution bulletin》2011,62(9):1979-1983

Environmental pollution due to heavy metals is having an increased impact on marine wildlife accentuated by anthropogenic changes in the planet including overfishing, agricultural runoff and marine emerging infectious diseases. Sea turtles are considered sentinels of ecological health in marine ecosystems. The objective of this study was to determine baseline concentrations of zinc, cadmium, copper, nickel, selenium, manganese, mercury and lead in blood of 22 clinically healthy, loggerhead turtles (Caretta caretta), captured for several reasons in Puerto López Mateos, Baja California Sur, Mexico. Zinc was the most prevalent metal in blood (41.89 μg g⁻¹), followed by Selenium (10.92 μg g⁻¹). The mean concentration of toxic metal Cadmium was 6.12 μg g⁻¹ and 1.01 μg g⁻¹ respectively. Mean concentrations of metals followed this pattern: Zn > Se > Ni > Cu > Mn > Cd > Pb and Hg. We can conclude that blood is an excellent tissue to measure in relatively non-invasive way baseline values of heavy metals in Caretta caretta.  相似文献   

山东省沂水县夏蔚铅及多金属矿地质特征及成因探讨          下载免费PDF全文

张强  刘安同  王春  梁建新  杨学生  刘同  夏立献  张士鹏 《山东国土资源》2006,22(5):38-41

沂水县夏蔚位于沂沭断裂带西侧,区内铅及多金属矿化特征明显,围岩主要为古生代寒武纪张夏组,基性岩浆含矿热液沿区域性断裂侵入于寒武纪张夏组受上部页岩屏蔽成矿,系碳酸盐型中低温热液充填—交代矿床。  相似文献   

氯化锌/氯化胆碱离子液体单晶合成、表征及性质研究          下载免费PDF全文

邱方龙  谢少磊  姚颖  景燕  孙进贺  贾永忠 《盐湖研究》2019,27(3)

选用溶剂挥发法,以氯化胆碱和氯化锌为原料,成功合成了一种新型的Zn(Ⅱ)单晶[Ch][ZnCl₃],并采用单晶X射线衍射、红外光谱、X-粉末衍射、元素分析等对单晶结构进行表征。结果表明:该晶体属于单斜晶系,空间点群为P 21/c,晶胞参数a= 7.322(4) ?, b = 9.423(5) ?, c = 16.688(8) ?, V = 1145.8(10) ?3, Z = 4, C5H14Cl3NOZn, Mr=275.89, Dc = 1.599 g/cm3, F (000) =560, m=2.797 mm_-1, R = 0.0524 and wR =0.1434. 通过热分分析,热分解温度为：323.5℃,具有较好的热稳定性,熔点为43℃, 相变焓94.1J.cm_-3。  相似文献   

Geological setting of the Rapu Rapu gold-rich volcanogenic massive sulfide deposits,Albay Province,Philippines     

Ross?L.?SherlockEmail author  Timothy?J.?Barrett  Peter?D.?Lewis 《Mineralium Deposita》2003,38(7):813-830

Gold-rich Fe–Cu–Zn volcanogenic massive sulfide deposits occur within strata of probable Jurassic age on Rapu Rapu Island in Albay Province, Philippines. Massive sulfides at the Ungay Malobago and Hixbar deposits are spatially associated with dacitic volcanic rocks within a highly-deformed sequence of mafic volcanic and quartzofeldspathic sedimentary rocks. The massive sulfide deposits formed at the stratigraphic contact between footwall dacites and hangingwall mafic volcanic and quartzofeldspathic rocks. The deposits and their host strata have undergone regional metamorphism with strong penetrative deformation. Metamorphic mineral assemblages and textural evidence suggest that peak metamorphism was upper-greenschist to lower-amphibolite grade and syn-D₁ deformation. Based on the age of regional metamorphism, deformation is inferred to be mid-Tertiary in age. Deformation at Rapu Rapu resulted in reorientation of the strata into a broad antiform with strong shallow-plunging elongation fabrics, overturning of the volcanic sequence that hosts the Ungay Malobago deposit, and complex folding of the mineralized zones. The present highly linear form of the Ungay Malobago deposit is mainly a product of this ductile strain.Immobile element ratios for a given lithology generally remain constant in saprolitic samples, and thus provide an effective identification tool even in strongly weathered rocks. Lithogeochemical data define a bimodal volcanic suite that is comparable to bimodal assemblages that occur in several modern back-arc basins in the southwestern Pacific Ocean, including those behind the Vanuatu and the New Britain arcs. On Rapu Rapu, the dacitic rocks are enriched in light REE and have high Zr/Y ratios, which indicates a calc–alkaline affinity and suggests a mature island-arc setting. The quartzofeldspathic sedimentary rocks are more widespread than the dacites and have notably lower Zr/Y ratios; they may have been derived from erosion of a distant volcanic arc. The mafic volcanic rocks are dominantly low-K arc tholeiites of basaltic to andesitic composition, but with modest enrichment in the light REE; comparable rocks can be found in the Vanuatu and New Britain back-arc basins.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00126-003-0349-0An erratum to this article can be found at Editorial handling: O. Christensen  相似文献   

广西贵港—平南地区铅锌矿带地质特征及找矿方向   总被引：4，自引：1，他引：4  

伍磊 《矿产与地质》2001,15(5):329-334

广西贵港－平南地区分布有华南大型－超大型铅锌矿成矿的有利层位，北东向两条深断裂具有多期活动性，泥盆系沉积盖层中下部第一层碳酸盐岩与成矿关系密切。具有较广阔的找矿前景。主要铅锌矿类型有热水沉积＋构造热液迭加改造型、复合叠加型。  相似文献