Total Heavy Metal Concentrations Research Articles

Shipboard Observations of Aerosol Chemical Properties Over the Western Pacific Ocean in Winter 2018

AbstractBased on a shipboard observation conducted in winter 2018, we reported the aerosol chemical properties and their differences in offshore and remote oceans over the Western Pacific Ocean (WPO). It's found that the chemical compositions over the WPO have significant spatial heterogeneity due to the influences of regional transport of anthropogenic aerosols and long‐path transport of dust aerosols. The average concentration of water soluble ions during the whole sampling period followed Cl− > OC > Na+ > > > Ca2+ > Mg2+ > EC > K+ > . Crustal elements of Ca (980.41 ng/m3), Na (971.55 ng/m3), and Al (781.16 ng/m3) were uniformly distributed in offshore area, but high proportion of Na elements dominated in remote regions. The total concentration of heavy metals including Zn, Cu, Cr, Pb and others originating from anthropogenic sources were 208 ng/m3 along the coastal region, about 10 times higher than that of 20.2 ng/m3 in the offshore and remote seas. For the reconstructed components, we found an increase of sea‐salt aerosol ranged from 3% to 72%, and a decrease of black carbon, organic matter and secondary inorganic salts, indicating a transformation from anthropogenic influence to marine environment. The rapidly increased secondary organic matter during dust event revealed that the transport of dust serves as catalysts to promote multi‐phase reactions. Cl− photochemical reaction rate in offshore area was mainly affected by sulfate from anthropogenic emissions, with an average chlorine loss rate of 18%, whereas it was inverse Cl− excess in the remote oceans.

Heavy metals in sludge from the sewage treatment plant network: a tool to evaluate source and risks of heavy metals to land application

ABSTRACT The aim of the study was to evaluate heavy metals concentration based on the total and chemical fractions of sewage sludge, to identify the sources of heavy metals and to assess ecological risks. Thirty-six anaerobic mixed sludge samples were collected from six different types of sewage treatment plant network in Dhaka city, Bangladesh. Total and fraction concentration of heavy metals in sludge samples were analysed by inductively coupled plasma mass spectrometer following acid digestion. The mean ranges of chromium (Cr), nickel (Ni), copper (Cu), arsenic (As), cadmium (Cd), lead (Pb), iron (Fe), manganese (Mn) and zinc (Zn) in the sludges were 237.3–381.8, 108.5–220.2, 116.1–207.2, 14.9–56.1, 0.68–2.86, 72.4–172.0, 12055 –20,015, 64.8–170.6 and 117.5–178.5 mg/kg, respectively. The data of geochemical speciation showed that Fe, Zn, Ni, Cu and Mn were associated with the residual fraction, whereas As, Cd and Pb showed predominant proportion in the exchangeable fraction, indicating the severity of risk by As, Cd and Pb to the surrounding ecosystem. The findings of the study revealed that heavy metals posed moderate to considerable ecological risk. Anthropogenic activities including industrial wastes and agricultural chemicals are substantial sources for heavy metals in the sludge of STP network in the study area.

Bioaccumulation of Heavy Metals and Hydrocarbons in Sediment, Shell and Flesh of the Faunas in Qua-Iboe River at Ibeno, Akwa Ibom State, Nigeria

Bioaccumulation of Heavy Metals and Hydrocarbons in Sediment, Shell and Flesh of the Faunas in Qua-Iboe River at Ibeno, Akwa Ibom State, Nigeria was undertaken. The faunas and sediment sample were collected from designated locations and a control location along Ikot-Ibok in dry and wet seasons using standard analytical sampling methods. The samples were analyzed for heavy metals and hydrocarbons content by atomic absorption spectrophotometer and gas chromatography respectively. pH of the samples was assessed. Transfer factor (TF) of the heavy metals between the sediment and the faunas were calculated. Regression models (linear and power equation) were developed to predict the numerical relationship between total petroleum hydrocarbon and total hydrocarbon content (TPH and THC) and heavy metals concentration in shell (predictor) of fauna in relation to their concentration in the flesh (dependent). Results obtained were subjected to statistical analysis such as coefficient of variation and mean. The concentration range of the heavy metals of both faunas and sediment was 0.001 – 86. 686 mg/kg. These value are above the World Health Organization and National Environmental Standard and Regulations Enforcement Agency (WHO/NESREA) standards (0.001 -5.0mg/kg). The coefficient of variation (C.V) had a range of 0.0152 – 193.333% which showed variation in stability of the heavy metals. Transfer factor (TF) showed that Tympanotomus fuscatus tissue bioaccumulated most heavy metals. Hydrocarbons (TPH and THC) and heavy metals concentration in the flesh of Ostreidea and Tympanomus fuscatus tissue were predicted from its shells at highly significant level (P - ≤ 0.05). This study has provided information on the levels of heavy metals and Hydrocarbons in faunas and sediment. In addition, the study has also developed models for predicting the levels of heavy metals and hydrocarbon content in the flesh from the shell of the faunas studied.

Evaluation of pollution with some heavy metals for soils and plants of agricultural Locations in Basrah province

To Evaluate the state of pollution with heavy metals (Zn, Cr, Cu, Ni, Pb), ten Locations with different chemical and physical properties were selected from the agricultural Locations of Basrah province: 1/Al-Qurna, 2/Al-Madina, 3/Al-Dair, 4/Al-Haritha, and 5/Karmat Ali (University). ), 6/ Al-Tanuma, 7/ Abu Al-Khasib, 8/ Al-Siba, 9/ Al-Faw and 10/ Al-Zubayr (Al-Burjisiya station) and a site was chosen for comparison, where soil samples were collected from agricultural Locations close to the source of pollution, while plant samples were collected from near and far from the source Pollution and the necessary analyzes were Carried out for the study. The results showed an increase in the concentration of total heavy metals in the soils of most of the study Locations, and they were polluted compared to the comparison treatment. The soils of most agricultural Locations exceeded the internationally permissible limits. The results indicated that the total average concentration of lead, Nickel, copper, chromium and zinc in the Hartha area (the fourth site) was 615.88, 165.55, 390.40, 48.45, 465.83 mg kg-1 soil sequentially, which is higher compared to the average concentration in other agricultural sites, as well as the concentrations of heavy metals increased (Pb, Ni, Cu, Cr, Zn) in plants grown in locations close from the source of pollution. The concentrations of these elements decreased in plants far from the source of pollution. It is noted that the pollution factor (CF) values of Pb and Zn in all study Locations ranged from moderate contamination to very high contamination. Keywords: PLI, pollution Factor (CF), oil installations, soil pollution, plant pollution.

Assessment of Trans-Environmental Transitions of Heavy Metals and Arsenic in Herbal Drugs and Herbal Medicinal Products of Valerian Rhizomes with Roots and Motherwort Herb

Scientific relevance. In the context of pharmacopoeial harmonisation, the available methods for quantifying the total heavy metal content in tinctures are not sufficient to demonstrate the safety of liquid dosage forms based on herbal drugs. However, the establishment of individual limits for the heavy metal content requires analysing the patterns of environmental toxicant transitions from plant raw materials to herbal medicinal products in finished dosage forms.Aim. This study aimed to analyse the trans-environmental transitions of heavy metals and arsenic from the soil through plants to herbal medicinal products using a case study of aqueous and alcoholic extracts of valerian and motherwort herbal drugs.Materials and methods. The study focused on motherwort herb and valerian rhizomes with roots, the corresponding herbal medicinal products, and the rhizospheric soil. The elemental composition of the studied samples was determined by inductively coupled plasma mass spectrometry.Results. The authors determined the content of 15 elements (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Cd, Sb, Hg, and Pb) in plant raw materials, the rhizosphere, and herbal drug infusions and tinctures. The concentrations of elements were 0.002–109.884 mg/kg in motherwort herb samples and 0.017–866.618 mg/kg in the samples of valerian rhizomes with roots. Pb, Cd, and As were detected in all plant raw materials, while Hg was found only in 25% of the study samples. The content of these elements was within acceptable limits. Valerian and motherwort infusions contained all elements, except for Hg; valerian tinctures were free from Fe and Hg; and motherwort tinctures included no Fe, Hg, Sr, Cd, and Pb. The concentrations of elements in the infusions did not exceed 3.169 mg/kg, while the concentrations of elements in the tinctures were below 1.27 mg/kg. In the tinctures, Zn, Cu, Mg, and Ti were the most abundant elements, and Sb and Cd were present in minimum amounts.Conclusions. Valerian and motherwort plants can concentrate Cu, Cr, Fe, and V from the soil. The transition of heavy metals and arsenic into infusions did not exceed 65% of the content of these elements in herbal drugs, while tinctures contained less than 30% of the content of heavy metals and arsenic in herbal drugs. Some elements passed into infusions 1.5–5 times more efficiently than into tinctures.

A comprehensive assessment on sludge conditioning by pyrite acid eluent-activated peroxymonosulfate based on dewaterability, heavy metals risk and ore recovery

Wastewater activated sludge (WAS) has poor dewaterability and contains heavy metals (HMs), limiting its land application. Therefore, in this study, a novel pyrite acid eluent-activated peroxymonosulfate (Fe2+pyrite/PMS) conditioning approach that can completely recover the residual pyrite and greatly reduce acid use was developed to improve WAS dewaterability, and the HMs chemical speciation and risks of conditioned WAS were assessed. Our results showed that under the optimized operational parameters, the capillary suction time (CST) and water content (Wc) of WAS decreased by 46.03% and 7.75%, respectively. Furthermore, during Fe2+pyrite/PMS conditioning processing, sulfate radical (SO4−) destroyed the extracellular polymeric substances (EPS) matrix, causing bound water release and the decrease of proteins/polysaccharides in outer layered EPS, even the decomposition of some protein-N in tightly bound EPS (TB-EPS) into inorganic-N. In addition, although the total concentration of HMs in the conditioned WAS matrix increased, the Ni concentration decreased in the solid fraction. Further, the risk assessment code (RAC) levels did not increase, and the eco-toxicity of Cr became weakened after Fe2+pyrite/PMS conditioning. However, after acid extraction, the pyrite residue had worsened recycle performance because the passivation layer contained S0/Sn2− on its surface, and no additional elements were detected in the pyrite residue, which had almost no effect on its further usage.

Establishment of a standardized ethanolic extract of Avicennia officinalis leaves in Vietnam

The mangrove plant Avicennia officinalis is widespread throughout the subtropical coast and is known for its many pharmacological properties, such as antibacterial, antiulcer, anti-inflammatory, anti-cancer, and antioxidant. This study determined the physicochemical parameters of the standardized extract, qualitative by phytochemical screening and thin layer chromatography (TLC), qualitative total phenolic content, and the content of the marker compound by high-pressure liquid chromatography (HPLC). Compounds such as p-coumaric acid and cinnamic acid have been found to be major phenolic acids in the leaves of this plant. These results provided useful information for the evaluation of the quality of Avicennia officinalis raw materials and its commercial products. The parameters of the ethanol extract of Avicennia officinalis leaves were obtained as follows: the loss of dry weight (10.9±2.09%), total ash content (22.31%), microbiological limits achieved to meet the requirements of medicinal standards, and total heavy metal content not detected. The content of total phenolics determined amounted to 81.83 mg GAE/g extract. The quantification method by HPLC was validated according to AOAC, and the content of two markers in the extract was p-coumaric acid (1.19 mg/g) and cinnamic acid (3.82 mg/g). The outputs of this research will be standardized extracts that’s the source of medicinal plants in Vietnam.

Changes in oral bioaccessibility of heavy metals in non-digestive sucking habits due to the formation of complexes between digestive fluid components and metals/metalloids

Humans, especially infants, are exposed to harmful substances through various means, including non-nutritive sucking behaviors. Here, we compared the “one-compartment model” and the “three-compartment model” within the “suck model” to assess the oral bioaccessibility of heavy metals in various products and evaluated whether these models can be employed to assess 12 heavy metals present in consumer products. Several certified reference materials, including plastic, paint, glass, and metals, were employed to ensure sample homogeneity. By comparing the two models, we validated that a considerable amount of complexes were formed between saliva components and the extracted heavy metals and that some of these complexes dissociated during reactions with the gastric/intestinal fluids. Furthermore, we observed that in the cases of Cu and Pb, additional complexes were formed as a result of reactions with gastric/intestinal fluids. We measured the total concentrations of the extracted heavy metals using artificial saliva through acid digestion and found that up to 99.7% of the heavy metals participated in the formation of complexes, depending on the characteristics of the sample (e.g., composition) and the target element. This result indicates that the current suck model may notably underestimate the oral bioaccessibility of heavy metals in products associated with sucking behaviors. Therefore, we propose a more conservative and simpler test method for assessing oral bioaccessibility of heavy metals that involves measuring the total concentrations of heavy metals extracted from consumer products using artificial saliva. By doing so, we can account for potential variations in the digestive milieu (e.g., due to ingested food) and the inconsistency in complex formation-dissociation characteristics.

Effects of biosolid biochar on crop production and metal accumulation through a rice-wheat rotation system in fields

ABSTRACT Biosolid-borne heavy metals are the main concern in soils. Therefore, the effects of biosolid biochar application in soils were evaluated in our study through a rice-wheat rotation in fields. The results showed that after the application of biosolid biochar, soil organic matter (SOM), soil pH, and soil total heavy metal concentrations (Cd, Zn, Cu, and Pb) were significantly increased. But the CaCl2 extracted metals concentrations were decreased, and no significant differences in metal concentrations of soil deeper layers (20–100 cm) were found among different treatments. The Cd, Zn, Cu, and Pb concentrations in rice decreased by 13.2%, 37.0%, 9.92%, and 63.0%, respectively, and the concentrations of Cd, Zn, Cu, and Pb in wheat decreased by 20.85%, 19.7%, 48.6%, and 23.6%, respectively, compared with the control treatment. Biosolid biochar can decrease metal availability in soils and increase crop production in fields, thus is suggested to use in fields.

Non-Negligible Ecological Risks of Urban Wetlands Caused by Cd and Hg on the Qinghai-Tibet Plateau, China.

The Huangshui National Wetland Park (HNWP) is a unique national wetland park in a city on the Qinghai-Tibetan Plateau, containing three zones: Haihu, Beichuan, and Ninghu. In this study, a total of 54 soil samples (18 sampling points with depths of 0-10 cm, 10-20 cm, and 20-30 cm) were collected in these three zones, and the contents of heavy metals (Cr, Cd, Cu, Hg, Ni, Pb, Zn, and As) of each sample were determined. The ecological risk of eight kinds of heavy metals was evaluated by using the geo-accumulation index (Igeo), and the ecological risk-controlling effect of the Xining urban wetlands on heavy metals was explored by comparative analysis, and the possible sources of heavy metals in the soil were analyzed via correlation analysis and principal component analysis (PCA). The results revealed that the total heavy metal concentration order was Haihu > Beichuan > Ninghu zone. As and Cu presented vertical accumulation characteristics in the surface and lower horizon, respectively. Cr, Cd, Hg, Ni, Pb, and Zn accumulated downwards along the depth. On the spatial scale, the enrichments of Cd and Hg brought non-negligible ecological risks in plateau urban wetlands. The results of PCA indicated that soil heavy metals mainly came from compound sources of domestic and atmospheric influences, traffic pollution sources, and industrial pollution sources. The study has revealed that human activities have inevitable negative impacts on wetland ecosystems, while the HNWP provides a significant weakening effect on heavy metal pollution.

Land Application of Biosolids-Derived Biochar in Australia: A Review

Thermal treatment in Australia is gaining interest due to legislative changes, waste reduction goals, and the need to address contaminants’ risks in biosolids used for agriculture. The resulting biochar product has the potential to be beneficially recycled as a soil amendment. On-farm management practices were reviewed to identify barriers that need to be overcome to increase recycling and examine the role of pyrolysis and gasification in effectively improving the quality and safety of biochar intended for land application. Key findings revealed the following: (1) thermal treatment can effectively eliminate persistent organic pollutants, microplastics, and pathogens, and (2) more than 90% of the total heavy metals content in biosolids may become immobilized when these are converted to biochar, thus reducing their bioavailability following land application. While the reported research on the short-term effects of biosolids-derived biochar suggests promising agronomic results, there is a dearth of information on long-term effects. Other knowledge gaps include the optimization of land application rates, understanding of the rate of breakdown, and the fate of contaminants in soil and water, including heavy metal mobility and redistribution in the environment by processes such as erosion and runoff following land application. An improved understanding of nutrients and contaminants dynamics in soils receiving biosolids-derived biochar is a pre-requisite for their safe use in Australian agriculture, and therefore, it is highlighted as a priority area for future research.

An integrated approach to assessing the ecological state of urban park soils, Kirov, Russia

Aim. Assess the ecological state of soils in park areas and public gardens in the city of Kirov, Kirov region, Russia, which are located near areas of heavy traffic, using an integrated approach based on data from physicochemical, microbiological analyzes and biotesting.Material and Methods. Soil samples were taken at various sites in the 60th Anniversary of the USSR Square, in the S.M. Kirov Park and in the 50th Anniversary of the Komsomol Park. The concentration of inorganic ions and the content of polycyclic aromatic hydrocarbons (PAHs) in the soils were determined by ionic and high‐performance liquid chromatography, respectively. The total content of heavy metals (HM)was determined by atomic absorption spectroscopy. Quantitative registration of microorganisms was carried out by the method of limiting dilutions with subsequent inoculation on selective nutrient media. Biotesting was carried out using the protozoa Paramecium caudatum and the Ecolum bacterial test system.Results. The features of the ionic composition of soils in Kirov parks were studied. In the aqueous extract of the studied soils, sulphate and chloride ions predominated among anions, and calcium ions among cations. Among the groups of microorganisms studied, ammonifying bacteria take the leading positions, the share of which in the microbial complex reaches 65.35–86.54%. There is a close relationship between the content of nutrients and the number of ammonifiers. The gross concentration of HMs in soil samples from parks in Kirov did not exceed their approximate permissible concentration, while the content of Pb, Zn, and Cо was up to 3.1 times higher than the regional background. The highest content of PAHs, maximum values of total carcinogenic activity and toxicity to P. caudatum were found in soil samples taken from areas near highways. Conclusion. The ecological state of urban park soils in Kirov in general can be characterised as satisfactory. Nevertheless, for park soils in the immediate vicinity of highways, increased values of PAH concentration were revealed. Determination of the PAH content in soils can be recommended for inclusion in the environmental monitoring programme in cities because of the persistence of PAHs in the environment, their mutagenic and carcinogenic properties, and the lack of standards for the content of most PAHs in natural environments.

An analysis of heavy metal contamination in vegetables and herbs growing in water hyacinth manure, case of Lake Chivero

The primary goal of this study was to determine concentrations of heavy metals in water hyacinth compost manure (Pb, Cd, Cu, Cr, and N) and their bioavailability in Brassica oleracea var acephala and mentha organs. Analysis also focused on the physiological responses of Brassica oleracea var acephala and mentha to water hyacinth compost.The target was to find if water hyacinth have high nutritive to enhance plant growth and act a an alternative solution for controlling water hyacinth if harvested from eutrophic Lake Chivero. Rhizofiltration ability of water hyacinth makes it potential source of fertilizer to plants since it accumulates all excess nutrients from hyper-eutrophic water sources. Before planting Mentha herb and Brassica oleracea var acephala, soil samples and compost were taken to the laboratory. The experiment was carried out in uncontaminated soil. For eight weeks, mature plants were harvested and their roots, stems and leaves were collected and plant materials were tested for heavy metal concentration to determine total metal concentration. The Bio-concentration Factor was used to calculate the concentration of heavy metals in Brassica oleracea var acephala and Mentha. The heavy metal accumulation rate in Brassica oleracea var acephala was calculated using a translocation factor. Heavy metal concentrations of Pb, Cd, Cu, Cr, and Ni were measured in compost treatments as well as Covo vegetables and mint herbs. Metal concentrations were greater than 1 mg/kg for Pb, Ni, Cu, and Cr, but not for Cd, which was below detection levels. The metals Pb, Ni, Cu, and Cr all had a BCF >1 mg/kg in Brassica oleracea var acephala and Mentha exceeded the WHO food safety guidelines. During the exposure experiments, the concentrations of Pb, Cd, Cu, Cr, and Ni in brassica oleracea var acephala vegetables and Mentha herbs increased. In decreasing order, Brassica oleracea var acephala and Mentha roots and leaves had the highest accumulation and total heavy metal concentration of Pb > Ni > Cu > Cd > Cr. In summary, water hyacinth from Lake Chivero cannot be used as a biofertilizer for food crops hence more research is required on other non-food crops and other uses like bio-fuel.

Occurrence, source identification and ecological risk assessment of heavy metals in water and sediments of Uchalli lake – Ramsar site, Pakistan

Uchalli Lake is an internationally significant Ramsar site that needs protection for supporting migratory birds. The current study aimed to assess wetland health by examining water and sediments utilizing total and labile heavy metals concentration, pollution indices, ecological risk assessment, water recharge and pollution induction sources through isotope tracer techniques. Al concentration in water was of serious concern as it was 440 times higher than the maximum acceptable concentration of Environmental Quality Standard of the UK for aquatic life in saline waters. Labile concentration predicted very severe enrichment of Cd, Pb, and moderate enrichment of Cu. Modified ecological risk index predicted very high ecological risk in sediments. The δ 18O, δ2H and D-excess values indicate that the lake was mainly recharged by local meteoric water. Enriched values of δ 18O and δ2H suggest a high evaporation of lake water, making lake sediments more enriched with metals. Isotopic and D-excess values of groundwater suggest a quick rainwater recharge to groundwater around the Uchalli Lake. Nitrates isotopes indicate that the rainwater runoff is main source of induction of fertilizers, pesticides and soil bonded metals in the lake system. The lake is recharged by rainwater runoff, from catchment areas, that erode the soil particles and agricultural residual waste dumped in the lake.

Long-Term Leaching Behavior and Geochemical Modeling of Cement Solidified Incineration Fly Ash Containing Waste Tires and Wood Biomass

Waste incineration is a widely used treatment method, and sustainable approaches are required to properly recycle large volumes of incineration ash to reduce environmental impacts and landfill space consumption. Studies have focused on the potential of recycling incineration ash as a replacement for natural aggregates in civil engineering applications, such as road construction. However, industrial waste incineration ash, such as waste tire incineration ash, contains hazardous heavy metals, such as lead and zinc that pose potential environmental threats. Moreover, few studies have investigated the leachability of these hazardous metals after long-term natural aging. This study investigates the long-term evolution of leachate chemistry, mineralogical transformation, and heavy metal fixation performance of a recycled roadbed material using ash from industrial waste incineration of waste tires and biomass (SFA). Additionally, field samples from a five-year pilot test site utilizing SFA were also examined. Regulatory leaching tests showed that the concentrations of Cd, Pb, As, T-Cr, and Ni were all below permissible limits even after five years of utilization. Long-term column leaching experiment results indicated that, compared to the total content of the SFA material, the leaching ratios of Pb, T-Cr, Cu, and Zn were 27%, 12%, 5%, and 0.1%, respectively. The SFA pH-stat leaching test results demonstrated that the mass release of the total content of heavy metals was relatively minimal, even under acidic pH conditions (pH < 4). Finally, profiles of pH and major ions in leachate from the column leaching experiment were simulated using HYDRUS HP1, implementing a dual-porosity modeling approach. In conclusion, despite containing hazardous heavy metals, SFA exhibits significantly low leaching rates over a long-term period.

Evaluating the Capability of Woody Plants to Capture Atmospheric Heavy Metals in Budapest

Urban green infrastructure planning plays an important role in aspects of pollution reduction, such as heavy metal trapping. However, the reduction effects are both influenced by the different pollution conditions in each city and the species-specific interaction of trees and pollution. Herein, we investigated three common urban woody plants (Acer platanoides L., Fraxinus excelsior L. Westhof’s Glorie, and Tilia tomentosa Moench) in Budapest to compare their heavy metal trapping abilities from the airborne in leaf dust deposits and leaves. All samples were deconstructed by a wet digestion method. Four high traffic-related heavy metal elements (Zn, Cu, Pb, and Ni) were determined by using an atomic absorption spectrometer (AAS). The investigated results showed that the relevant concentration of all measured elements was constant in all species, namely Zn < Cu < Pb < Ni. Although the total heavy metal content in the dust deposit increased towards the end of one vegetation period, the highest percentage of total metal concentration was in the summer season as the particulate matter sources varied in each season. These indicate that woody plants are ideal candidates for pollution monitoring. All of the evaluated elements were loaded highest in the dust deposit of T. tomentosa during all sampling times, followed by A. platanoides, and the least in F. excelsior. A significant correlation between metal contents in the dust deposit and leaf was found in T. tomentosa (0.926 at a p<0.01 level). Therefore, we suggest T. tomentosa, which has better atmospheric trace element capturing capacity than A. platanoides and F. excelsior and thus it is a better option for pollution reduction in the urban area.

Risk assessment of available and total heavy metals contents in various land use in calcareous soils

Risk assessment of available and total heavy metals contents in various land use in calcareous soils

Report on the impact of anthropogenic factors on the properties and functions of soils from a selected area of Central European Lowland province

PurposeThe study aims to assess the impact of human activity on the content and migration of trace elements in soil profiles of various physico-chemical properties. The research hypothesis assumed that human impact related to the functioning of buildings, agriculture, industry and communication negatively affected the trace element contents and physico-chemical properties of soils in a selected urban area (the Grudziądz Basin).Materials and methodsSeven soil exposures were made in areas that differed in land use and soil type over an area totalling approx. 200 ha. In the soil profiles, samples of soil of disturbed structure were taken from each genetic horizon. Selected physico-chemical properties of soils were determined: soil texture, soil pH, TOC, CaCO3 content. The total content of heavy metals in the soils was determined by AAS after digestion in hydrofluoric acid and bioavailable forms in 1 M DTPA. The sources of elements in the studied soils were assessed using the following indices: Enrichment Factor (EF), Geoaccumulation Index (Igeo) and Contamination Factor (CF).Results and discussionThe sand fraction dominated the examined soil profiles, with its content ranging widely and averaging 64.7%. In general, the humus horizons had lower pH values than the deeper layers and parent rock horizons. The organic carbon content ranged from 0.07 to 4.64%. The vertical decomposition of total N was strongly related to the decomposition of organic carbon. The highest metal contents in the soil samples were for zinc, and then for nickel. Conversely, the lowest concentrations were for mercury. Most of the profiles had higher contents of the analysed elements in their upper horizons. The humus horizons were characterised by the accumulation of Cr, Hg, Zn and Fe. The samples from the soil profiles were highest in bioavailable forms of zinc and nickel.ConclusionsThe assessment of human impact on the concentrations and migration of trace elements in profiles of agricultural soils found the contents of heavy metals to be variable. Only in a few profiles were EF values for Cd, Pb and Ni found to indicate the effects of human activity. Likewise, CF and Igeo attest to only slight contamination in the research area.

Evaluation of the Feasibility of Utilizing Composted Sludge from Leather Industry Wastewater in Sudan

The objective of this study is to assess the potential for composting chromium-rich sludge from the leather industry wastewater in Sudan, with the aim of removing or capturing heavy metals before they can leach into the surrounding environment. “This research aims to evaluate the pH, organic matter, total nitrogen, phosphorus, potassium, and calcium content of compost made from leather industry wastewater sludge, as well as determine the level of bioavailability of heavy metals. To create the compost, the leather industry wastewater sludge was mixed with organic waste such as chicken manure, rice bran, and sawdust in various ratios, and then shaped into block piles for the composting process. The results indicate that for the recommended block-shaped piles, the organic content decreased from 30% to 25%, while the pH value and NPK content were satisfactory for composting. Additionally, the total heavy metal content, including Cr, Cd, Cu, Pb, Mn, and Zn, was well below the upper limit standard for biosolids, which classifies the compost as excellent." "The compost was found to be free of Salmonella sp., Shigella sp., and helminth eggs, and there was a 103-fold decrease in total coliforms. The compost characteristics indicated that it was mature, and the germination index for cabbage seeds was 85.5%, which suggests that most of the phototoxic compounds were removed."

Urban soil quality deteriorates even with low heavy metal levels: An arthropod-based multi-indices approach.

Urban-induced habitat conversion drastically changes soil life in a variety of ways. Soil sealing, human disturbance, habitat fragmentation, industrial and vehicular pollution are the main causes of urban soil degradation. Soil arthropods, as one of the most abundant and diverse group of soil fauna, are involved in many soil processes that are of great importance in maintaining soil health and multifunctionality. Nevertheless, soil quality is still mainly characterized by physical, chemical, and microbiological parameters. Here, we assessed and compared the biological soil quality in woody (REF: reference forest, REM: remnant forest) and nonwoody (TURF: public turfgrass, and RUD: ruderal habitat) types of urban green spaces along a disturbance and management intensity gradient in the Budapest metropolitan area (Hungary), using community metrics and soil arthropod-based indicators. Vegetation cover and landscape characteristics of study sites were quantified through vegetation and urbanization indices, respectively. Basic soil properties, total and bioavailable concentrations of the main heavy metals (Cd, Co, Hg, Ni, Zn) were also measured. Acari, Collembola, and Hymenoptera (mainly Formicidae) were the most abundant groups. Litter-dweller taxa, particularly Protura, proved to be the most sensitive to urban disturbance. Representatives of Hemiptera, Diptera, Symphyla, and Pauropoda were common in low densities. The taxonomic diversity of soil arthropod assemblages in nonwoody and woody habitats was similar. Although the integrated faunal indices showed no differences among soil habitat types, they provided different responses and, consequently, different information. Our findings demonstrated that the biological quality and arthropod community structure of soils were strongly impacted by soil C/N and heavy metal contamination. We found that low and moderate levels of pollution have adverse effects on edaphic fauna, suggesting biological degradation of soils, even below pollution limits. Nevertheless, more disturbed urban green spaces have been shown to play a significant role in maintaining belowground biodiversity, thereby soil functions.