Solubility of ion and trace metals from stabilized sewage sludge by fly ash and alkaline mine tailing

Stabilized sewage sludge （SS） by fly ash （FA） and alkaline mine tailing as artificial soil, to be applied on the ecological rehabilitation at mining junkyards, offers a potentially viable utilization of the industrial by-product, as well as solves the shortage of soil resource in the mine area. An incubation experiment with different ratios of SS and FA was conducted to evaluate the solubility of ions and trace elements from stabilized sewage sludge. Results showed that fly ash offset a decrease in pH value of sewage sludge. The pH of （C） treatment （FA：SS = 1：1） was stable and tended to neutrality. The SO4^2- and Cl^- concentrations of the solution in the mixture were significantly decreased in the stabilized sewage sludge by alkaline fly ash and mine tailing, compared to the single SS treatment. Stabilized sewage sludge by FA weakened the nitrification of total nitrogen from SS when the proportion of FA in the mixture was more than 50%. The Cr, Ni, and Cu concentrations in the solution were gradually decreased and achieved a stable level after 22 days, for all treatments over the duration of the incubation. Moreover stabilized sewage sludge by fly ash and/or mine tailing notably decreased the trace metal solubility. The final Cr, Cu, and Ni concentrations in the solution for all mixtures of treatments were lower than 2.5, 15, and 50 μg/L, respectively.     

试剂对微量汞分析的影响及其引起的“干扰异常”的排除

用ＸＧ－冷原子吸收型数字测汞仪对水汞等进行纳克级别以下的极微含量分析。测量中加入的一些试剂影响测量数据的准确性和稳定性。对此笔者进行了一些实验研究。本文分析和介绍了测定中添加试剂的影响情况和一些实测数据分析实例；并提出了一般的解决方法，在地震和其他领域微量汞测量中有使用价值。     

TOXIC TRACE ELEMENT POLLUTION IN GROUND WATERS AROUND PATANCHERU AND BOLARAM INDUSTRIAL AREAS, ANDHRA PRADESH, INDIA: A GRAPHICAL APPROACH

Patancheru and Bolaram are satellite industrial towns nearHyderabad with over 300 large andmedium scale pharmaceutical, heavy engineering, paints, paperand chemical factories. The industriesof the area generate a cumulative 8 × 10⁶ l/day ofeffluents which are being directly dischargedon to surrounding land, irrigation fields, and surface waterbodies which finally enter into theNakkavagu River a tributary of the Manzira River. The presentstudy on abundance and distributionpattern of toxic trace elements indicates the quantitativeaspect of pollution in the Nakkavagu Basin.Migration patterns drawn for TDS, toxic elements such as Cu,As, Se, Zn, B, Cr and iron indicate thatpollutants discharged by the industries are entering thesurface and groundwater system (aquifers) andare also migrating towards the Manzira River furtherdeteriorating the entire hydrological setup of the area.Entry and dispersion of pollutants in the hydrological systemis shown by distribution diagrams. Aconservative estimate indicates that the effect of pollutantson the agricultural lands and water bodiesextends 0.25 to 0.5 km to either side of the Nakkavagu Riverover a length of 25 km. In addition tothis, the movement of pollutants with ground water in thedownstream direction worsened thehydrological system and increased the possibility ofgeo-accumulation of pollutants in biota. Openwells, dug wells and tanks have become useless and redundantas the concentrations of Cu, Se, As,B, Cr and Fe have increased to 5 to 10 times the permissiblelimits. Several villages have beenaffected by the toxic pollutants in the area. The groundwatersystem is polluted over a large area asshown in elemental migration diagrams and is not potable.Tentatively an area of 20 sq km can becategorized as the worst affected by various pollutants.     

Elemental Analysis of Water and Sediments by External Beam Pixe Part 3: Axios (Vardar) River, Greece

The Axios (Vardar) River originates from the south west part of Yugoslavia, transverses Greece, and discharges into the Thermaikos bay in the north Aegean Sea.

The proton induced X-ray emission (PIXE) method with external beam was used for the elemental analysis of water and sediment samples, while measurements of water temperature, dissolved oxygen content, conductivity, pH, and the water flow were made in situ. Water samples were also analysed for total phosphates, nitrates, chlorophyll, and BOD. The data collected for a 16-month period indicate that the Axios River is polluted as far as the metal content is concerned; its primary productivity is low and it is slightly enriched during its course into the Greek territory.     

ESTIMATING CENTRAL TENDENCY FROM UNCENSORED TRACE LEVEL MEASUREMENTS1

ABSTRACT: The statistical analysis of data which have trace level measurements has traditionally been a two-step process in which data are first censored using criteria based on measurement precision, and then analyzed with statistical methods for censored data. The process might be more informative if data were left uncensored. In this paper, information loss attributable to censoring and measurement noise are assessed by comparing the sample mean and median of uncensored measurements with a log regression mean and median based on censored data. Measurements are derived from lognormal parent distributions which have random variability characteristic of trace level measurement. The relative performance of estimators used with error-free samples and with samples having measurement noise can be explained by differences between the probability distributions of parents and measurements. Measurement introduces bias and dispersion and transforms lognormal parent distributions toward greater symmetry. Estimates using uncensored data are less biased and more accurate than the log regression mean and median when censoring exceeds about 50 percent, and are not much worse at any fraction censored. For data with many (80 percent) results below the limit of detection, bias may be quite severe.     

TRACE METALS IN SEDIMENT: SPATIAL TRENDS AND SORPTION PROCESSES1

ABSTRACT: Sediment bound trace metals are often examined for spatial trends such as downstream patterns or distance from a source. Spatial trends may indicate either differences in metal inputs, or, when considerable sediment variability exists, differences in sediment sorption processes. These two possibilities become important not only when sediment contamination is evaluated within an area, but also when regulatory agencies attempt to make equivalent among area decisions. Sediments from an urban watershed were examined for: (1) downstream trace metal trends and (2) sediment sorption relationships. Analyses determined that downstream trenda as related to metal inputs could not be recognized by analyzing the < 2mm (≤, sand) sediment size fraction. Conversely, the trace metal concentrations were found to be distinctly related to sediment characteristics. The watershed's metal concentrations are similar to those found in uncontaminated to slightly contaminated sediments in the United States.     

Termite assemblages in a West-African semi-deciduous forest and teak plantations

Responses of termite assemblages to the conversion of semi-deciduous forest into teak plantations were studied in the Lama Forest Reserve in Benin, West Africa. Four belt transect surveys were run in each of the two forest types, adopting a modified termite diversity assessment protocol. Termite assemblages were remarkably species-poor in both forest types, with only 19 species encountered altogether. The low species richness was due to the rarity of soil-feeders of the soil/humus interface and the absence of true soil-feeders in the compact vertisol soil. Species richness was significantly higher in semi-deciduous forest than in teak plantations, but termite encounters were significantly lower. Termite assemblage and feeding group structure differed significantly among forest types. Wood-feeders were recorded only in semi-deciduous forest. In contrast, fungus-growers were more species-rich and about four times more abundant in teak plantations, mainly due to one Ancistrotermes species. The humification score, which depicts the position of termite assemblages along a gradient of increasing humification of their food substrate, was significantly higher in teak plantations, due to the absence of wood-feeders and the preponderance of fungus-growers. Combined principal components and multiple regression analysis identified two significant predictors of termite assemblages, soil water content and leaf litter biomass. The abundance of fungus-growers in teak plantations seemed to be mainly related to the high leaf litter biomass. Indirect evidence also suggests that lower predation pressure by ants on termites in teak plantations may have contributed to the abundance of termites.     

Time series analysis of elemental and isotopic data from biomineralized whale tissue

A temporal record of environmental conditions is often contained within accretionary biological tissue. These records can provide knowledge of the environmental conditions that existed at the time the tissue was formed. In this study, we look at trace element concentrations and isotopic ratios of carbon and nitrogen as contained in baleen from bowhead whales in the eastern and western Arctic Ocean. Time series techniques, including maximum likelihood method and likelihood ratio tests, are applied to analysis of data and inference about their mean structures.     

北京东郊污灌区表层土壤微量元素的小尺度空间结构特征

岩溶山区表土中＾７Ｂｅ、＾１３７Ｃｓ、＾２２６Ｒａ和＾２２８Ｒａ地球化学相分配的实验研究表明，４种核素绝大部分存在于Ｆｅ－Ｍｎ氧化物，有机质及残渣相中。它们在表土的迁移过程中具微粒迁移性，能较好地随土粒般运，可作为土粒侵蚀或沉积的示踪剂。     

Interactions of copper,cadmium and molybdenum in buffalo calves:the levels of trace element in blood,urine and tissues

Ten male buffalo calves were randomly allotted into five groups of two each. Four groups were fed with cadmium, molybdenum, cadmium-molybdenum, and copper-cadmium-molybdenum respectively for 130 days to determine the elements' metabolic interactions in calves. These results indicated that cadmium and molybdenum could increase the accumulation of molybdenum and cadmium in liver and kidneys in buffalo calves, but copper could not. reduce to normal the levels of molybdenum and cadmium in liver and kidneys caused by cadmium-molybdenum. In addition, we found the copper concentrations in liver and kindeys was significantly greater in treatment calves than in controls.