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A total of 214 sampling sites of a hazardous waste disposal center were surveyed in a two-stage pollution investigation, including soil boreholes and groundwater monitoring wells. Results showed that chemical oxygen demand (COD) (4.00–2930.00 mg/L), fluoride (0.07–9.08 mg/L), chromium (0.12–1.20 μg/L), nickel (0.15–459.00 μg/L), lead (0.10–10.20 μg/L), cadmium (Cd) (0.05–16.40 μg/L), and beryllium (0.06–3.48 μg/L) were detected in groundwater samples. For soils, Cd in soil (78.7 mg/kg) exceeded the risk screening value (65 mg/kg) for soil contamination of the second type of development land (GB36600-2018), and there remained the risk of leakage in the landfill detection investigation. Then, a health risk assessment was carried out. Based on the definitions of the groundwater exposure pathway (HJ 25.3-2019) and the pollution investigation of groundwater, the carcinogenic and non-carcinogenic risks of groundwater were generally considered to be negligible. The carcinogenic risk and non-carcinogenic risk of the concerned pollutant in soil for risk assessment (Cd) under the condition of reutilization exceeded the corresponding acceptable levels (1E-06 and 1). The (non-)carcinogenic risk of Cd mainly came from oral intake of soil and inhalation of soil particles under two conditions of reutilization and non-utilization, so on-site workers and surrounding residents should be properly protected from the mouth and nose to minimize the intake of pollutants from the soil and soil particles. The area of soil contaminated by Cd was about 630.58 m2, and the amount of pollution was about 1261.16 m3. The heavy metal pollution was only distributed in the depth range of 0–2 m, and the suggested risk control value of soil pollutants under the condition of reutilization for Cd was 56 mg/kg. Based on different pollution characteristics of soil, groundwater, and the landfill, targeted control measures were proposed.

Collection of soil samples is labored, time-consuming and the determination of heavy metal concentrations in the laboratory are expensive. The aim of this study was to fix the functions, algorithms as well as optimization of methods for soft computing system such as ANFIS, SVM, and ANN based on their best performance. In this study, soil samples were collected from eighty five distinct locations in and around of a selected open disposal site at old Rajbandh, Khulna, Bangladesh at a depth 0-30 cm from the existing ground surface. In the laboratory, the concentration of heavy metals such as Pb, Cu, Ni, Zn, Co, Cd, As, Sc, Hg, Mn, Cr, Ti, Sb, Sr, V and Ba in soils were measured. The soft computing systems such as ANFIS, SVM, and ANN were implemented for the analysis of heavy metal concentrations in soil. The result reveals model with SCP, gaussmf, linear and hybrid was the best-fitted model of ANFIS. In addition, in SVM analysis, the model SVM-RBF with 15 folds was selected. In ANN, the model LT (Levenberg-Marqardt and Tansig functions) with neuron structure 2-10-1 was selected. The accuracy of the predicted results was checked based on the acceptable limits of prediction parameters such as R value, RMSE, MAPE, GRI and percentage recovery. The result demonstrates that ANFIS model was a reliable technique than that of other counterparts of SVM and ANN with the acceptable degree of robustness and accuracy. Therefore, the performance of soft computing systems may be expressed by the sequence of ANFIS > SVM > ANN. Here it can be noted that one can easily be computed the concentration of a particular heavy metal in soil by inserting GPS values (latitude and longitude) only in the developed rule viewer of ANFIS. [ABSTRACT FROM AUTHOR]

This paper presents the distribution of heavy metals in a groundwater system at a solid waste disposal site in Taiping, Perak. In this study several boreholes were constructed within the solid waste disposal site. Soil samples were collected from the alluvial deposits at 1 m intervals between 6 and 30 m depths from 6 boreholes using a down-hole hammer. The pore water content of the samples and the ground water was extracted in order to determine the concentrations of heavy metals, such as lead (Pb), manganese (Mn), chromium (Cr), iron (Fe), zinc (Zn) and cadmium, (Cd) using the Inductively Couple Plasma Spectrometer (ICP-MS). From the profiling results, the penetration of heavy metals into the groundwater system was obtained. A profile of heavy metal concentrations in the pore water of the core samples at several boreholes within the study area, and heavy metals concentration in groundwater under different conditions were obtained. Some of the heavy metals concentration such as Pb, Mn, Zn and Fe were high. These high concentrations exceed the maximum permissible concentration as specified in the Drinking Water Standard. Based on contour diagrams, the heavy metals can be detected down to 25 m depth towards the southeast of the landfill and appear to be localized. [ABSTRACT FROM AUTHOR]

Short rotation coppice cultures (SRC) are intensively managed, high-density plantations of multi-shoot trees. In April 1996, an SRC field trial with 17 different poplar clones was established in Boom (Belgium) on a former waste disposal site. In December 1996 and January 2001, all shoots were cut back to a height of 5cm to create a coppice culture. For six clones, wood and bark were sampled at the bottom, middle and top of a shoot in August and November 2002. No significant height effect of metal concentration was found, but for wood, metal concentrations generally increased toward the top of the shoot in August, and decreased toward the top of the shoot in November. Phytoextraction potential of a clone was primarily determined by metal concentration and by biomass production. Shoot size and number of shoots per stool were less important, as a high biomass production could be achieved by producing a few large shoots or many smaller shoots. Clone Fritzi Pauley accumulated 1.4kgha-1 of Al over two years; Wolterson and Balsam Spire showed a relatively high accumulation of Cd and Zn, i.e. averaging, respectively 47 and 57gha-1 for Cd and 2.4 and 2.0kgha-1 for Zn over two years. [Copyright &y& Elsevier]

The use of plants to decontaminate soils polluted by heavy metals has received considerable attention in recent years as a low-cost technique. Poplars (Populus spp.) can accumulate relatively high levels of certain metals, and have the added advantage of producing biomass that can be used for energy production. A short rotation coppice culture with 13 poplar clones was established on a former waste disposal site, which was moderately polluted with heavy metals. Total content of metals in leaves, wood and bark were determined in August and October/November. Significant clonal differences in accumulation were found for most metals, although clones with the highest concentration of all metals were not found. Cadmium, zinc and aluminium were most efficiently taken up. The lowest concentration was found in wood; the highest concentrations were generally found in senescing leaves, making removal and treatment of fallen leaves necessary. [Copyright &y& Elsevier]

This article discusses the estimating of contaminant distributions in environmental media in the context of its necessity in evaluating human and ecological hazards. Because of uncertainties in release histories and transport, traditional sampling and statistical techniques applicable to the experimental sciences may not be suitable for exploratory studies at hazardous waste sites. An approach that relies on cluster analysis of principal components (PCA) was used to identify contaminated wild asparagus growing in the vicinity of waste disposal sites along the Columbia River in southeast Washington state. Metals in soil samples taken from the sites contained elevated levels of silver (Ag), aluminum (Al), barium, (Ba), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), antimony (Sb), zinc (Zn), and vanadium (V). Samples of asparagus tissue were collected from the river near the waste site, from Hanford oil fields abandoned 52 year years ago, and from commercial fields in the neighboring communities. Dried tissues were analyzed for metals content by ICP‐mass spec‐trometry, furnace AA, and cold vapor AA. Tissue concentrations of elements varied over five orders of magnitude. [ABSTRACT FROM AUTHOR]