Determination of heavy metal elements concentration in soils and tailing sediments from lateritic nickel post-mining areas in Motui District, Southeast Sulawesi

Heavy metal elements concentration study has been determined from soils and tailing sediments in laterite nickel post-mining area in Motui District Southeast Sulawesi. This study aimed to determine the concentration of some heavy metal elements, especially Fe, Co, Mn and Cr, from surface soils sediments in waste dump sites and tailing sediments in settling ponds from lateritic nickel post-mining areas. A total of 20 samples consisting of 18 soil samples and 2 tailing sediments samples were systematically collected for the study. The soil samples from the waste dump site profile were collected from 3 layers which were divided based on the colour of the soils from top to bottom, namely Layer C, Layer D and Layer E. Six soil samples were taken from each layer with space between each sample in one layer was about 50 – 60 cm. The samples were sent to the laboratory and analysed using Atomic Absorption Spectrometer (AAS) method to determine the concentration of heavy elements. Metal-bearing minerals detected from the bedrock consists of chromite, manganese, magnetite and limonite which are responsible for the Cr, Mn and Co, and Fe content, respectively. The result showed that Fe content is significantly higher in soil samples from Layer C and tailing sediments with dark red to brown in colour, suggesting the strong relation between Fe content and colour index. The general element mobility trend showed that Mn and Co are positively correlated in soil sampling from all layers and tailing samples, whereas Fe and Cr show a negative correlation trend in Layer C, D and tailing sediments but positively correlated in Layer E.

Portable X-Ray Fluorescence (pXRF) Analysis of Heavy Metal Contamination in Graveyards with Contrasting Soil Types

Human remains have been interred in burial grounds since historic times. Although the re-use of graveyards differs from one country, region or time-period to another, over time graveyard soil may become contaminated or enriched with heavy metal elements. This paper aims to present heavy metal element soil analysis from two UK church graveyard study sites with contrasting necrosols, but similar burial densities and known burial ages dating back to the 16th Century and some possibly older than 1,000 years. Portable X-Ray Fluorescence (pXRF) element analyses were undertaken, both in-situ on surface locations and laboratory-based on surface and near-surface soil pellets. Results show elevated levels of Pb, Mn, Cr, Cu, Zn and Ca in both necrosols when compared to background values. Element concentration anomalies remained consistently higher than background samples down to 2 m bgl, where sampled, but reduced away from church buildings which may reflect burial densities. Element concentration anomalies were higher in the clay-rich necrosol than in sandy necrosol. Field-based rapid measurements gave similar relative concentration values to laboratory-based soil pellet measurements, although laboratory-based analyses were more precise. Study results implications suggest that long-used necrosols are likely to be more contaminated with heavy-metal elements than similar soil outside graveyards with implications for burial grounds management, adjacent populations and where burial grounds have been deconsecrated and turned to residential dwellings.

Heavy Metal Contamination of Urban Mangrove Sediments and Their Environmental Significance in the Zhanjiang Bay

Urban mangroves can be used to measure the impact of human activities on the urban ecological environment because mangroves are sensitive to human activities. However, studies on the evaluation of heavy metal elements in urban mangroves are still limited. Consequently, this study selected the urban mangroves in a central commercial area of Zhanjiang Bay as a case study to investigate the content and distribution of the heavy metal elements in mangrove sediments. Combined with the results of elemental analysis, grain size analysis, risk level, influencing factors, and sources of heavy metal pollution in the surficial sediments of the mangroves in the study area were evaluated based on mathematical models and multivariate statistical analysis. The results show that (1) concentration of heavy metals: V> Pb> Cu> Ni> As> Co> Cd> Hg; (2) the content of the eight heavy metal elements has a significant positive correlation with total organic carbon (TOC) and total nitrogen (TN) values, likely as a result of adsorption, complexation, or precipitation of heavy metals by organic matter in the sediments; (3) the mangrove sediments in the study area are affected by heavy metal pollution, among which Cd pollution is the heaviest, followed by Hg pollution; (4) comprehensive analyses of multiple heavy metals using Potential Ecological Risk Index shows that the risk level of the study area is slight to very strong ecological risk; (5) the heavy metals in the study area are mainly derived from human activities such as urban domestic sewage, transportation, and ship pollution.

Pollution Characteristics and Risk Assessment of Heavy Metal Elements in Sediment in the West Lake of Hengshui Lake

21 sampling points were set in the West Lake of Hengshui Lake including 20 fish ponds and 1 natural pond to analyze the contents distribution of heavy metal elements including Cr, Zn, Pb, Cu, Cd, Hg, As, and Sb in sediment. The degree of heavy metal pollution was evaluated by the geoaccumulation index (Igeo) method. The results showed that the concentrations of Cr, Zn, Pb, Cu, Cd, and Hg at in all sampling points of the fish ponds were lower than soil risk screening values of agricultural land in soil environmental quality: risk control standard for soil contamination of agricultural land (trial) (GB 15618-2018). The concentrations of As at 5 sampling points were higher than soil risk screening values and lower than soil risk control values of agricultural land in GB 15618-2018. The concentrations of Sb were lower than soil risk screening values of construction land in soil environmental quality: risk control standard for soil contamination of development land (trial) (GB 36600-2018). The evaluation results of the geoaccumulation index method showed that the pollution degrees of Cd, Pb, and Hg were moderately contaminated in general, the pollution degree of Cu was uncontaminated to moderately contaminated in general, the pollution degrees of Cr and As were uncontaminated to moderately contaminated in some sampling points, and Zn and Sb could be regarded as uncontaminated in sediment of the fish ponds in the West Lake of Hengshui Lake. Otherwise, the average contents of other heavy metal elements in sediment of the fish ponds in the West Lake of Hengshui Lake were higher than the background value of soil in Hebei Province (BVSH) except for Zn and Sb. The average contents of seven heavy metal elements in sediment of the natural pond in the West Lake of Hengshui Lake were lower than BVSH except for Cr. The result can be regarded as no pollution in the natural pond because the values of Igeo were all lower than 0. The heavy metal pollution in the sediment of the West Lake of Hengshui Lake may be due to the introduction of feeding. The water environment of the West Lake of Hengshui Lake can be effectively improved by cleaning up the sediment of fish ponds and “returning fishing to wetland.”

Visually sorting waste wood — an exploratory study

Waste wood collected at the Vancouver landfill has been sorted based on the visibility of coatings, paints, and the green colorization of wood typically associated with wood preservatives. The sorted material was then ground and tested with an inductively coupled plasma mass spectrometry (ICP–MS) for heavy metal elements that are toxic or harmful to humans and (or) the environment. Results indicated that wood preservatives were not visually detectable but paints and coatings were. Therefore, the study demonstrated that visual sorting is not sufficiently accurate to distinguish between treated and clean or untreated waste wood.

Identification of Elemental Composition and Heavy Metal Content in Maninjau Lake Sediment Using X-Ray Fluorescence (MNJ 18-41B)

Maninjau Lake is a caldera lake located in Agam, West Sumatra. This lake was formed from the volcanic activity of Mount Maninjau Purba about 60,000 years ago. The volcanic material resulting from the eruption is scattered and deposited in various places, one of which is in lake sediments. Volcanic ash contains various types of elements, including heavy metal elements. This study aims to determine the composition and content of heavy metal in the sediments of Maninjau Lake. The sample analyzed was MNJ 18-41B with a core length of 440 mm, focusing on specimens 148 mm and 376 mm. The selection is a specimen based on the magnetic susceptibility value obtained from the measurement meter susceptibility of the MS2E. Specimen 148 has a value susceptibility low of 2.1 × 10-8 m3/kg, while the 376 specimens have the highest value of susceptibility, the highest 141 × 10-8 m3/kg. The content of sediment elements was determined using the results of X-Ray Fluorescence (XRF) measurements. The measurement results showed that the mineral-forming elements in the sediments of Lake Maninjau were dominated by Si, Fe, Rh, and Zr. In contrast, the highest heavy metal elements are Mn, Fe, Sr, and Rh. Based on the elemental composition and mineral oxide compounds in the sediments of Lake Maninjau derived from volcanic ash.