Accumulation Rates Of Heavy Metals Research Articles

Accumulation Characteristics and Influencing Factors of Heavy Metals in Cultivated Land Surface Soil in Lanzhou

In this study, As, Cd, Cr, Hg, and Pb in the surface soil of cropland in Lanzhou were studied, and the combination of descriptive statistics, single-factor accumulation index, comprehensive accumulation index, geostatistical method, and a geographically weighted regression model (GWR) was used to investigate their accumulation status, spatial distribution, and influencing factors, in order to provide scientific basis for the precise control of heavy metal accumulation risk in the study area. The results showed that:①the single-factor accumulation index showed that the accumulation of Hg and Cd in the study area was the largest, followed by that of Pb and As, and that of Cr was the smallest; the comprehensive accumulation index showed that the accumulation rate of heavy metals was as high as 98.11%, of which 54.81% was mild accumulation and 43.30% was moderate and above accumulation. However, there was no heavy metal pollution in the surface soil of cultivated land in Lanzhou. ② Spatial autocorrelation analysis showed that there was no heavy metal pollution in the surface soil of Lanzhou, but there was accumulation in a few areas. The spatial autocorrelation analysis showed that the spatial autocorrelation of the Cr, Hg, and Pb single-factor accumulation indices was moderate, indicating that they were influenced by both random and structural factors; the spatial autocorrelation of the other two heavy metals was weak, indicating that they were mainly influenced by random factors, among which human factors were more influential. The Hg single-factor accumulation index was high in the middle and low in the fourth; the integrated accumulation index increased from northwest to southeast and decreased from the middle to both sides. ③ Geographically weighted regression (GWR) analysis showed that altitude, slope length, distance from rivers, soil organic matter (SOM) content, precipitation, air temperature, and surface temperature all showed positive driving effects, whereas the rest of the factors showed negative driving effects and significant spatial heterogeneity and instability (P<0.05). The magnitudes of the factor effects were in the order of soil characteristics>topographic characteristics>climate characteristics>location characteristics>socioeconomic characteristics>vegetation characteristics, with the largest contribution of SOM content, followed by that of altitude and air temperature, and the smallest of normalized difference vegetation index (NDVI) values. Compared with the other feature factors, the location feature factors had stronger spatial heterogeneity.

Anthropogenic Contribution and Migration of Soil Heavy Metals in the Vicinity of Typical Highways

To reveal the secondary anthropogenic contribution and accumulation rate of heavy metals in highway-side soils, we studied soil heavy metals on three representative highways in Southeast China, with different traffic intensities, service years, land use patterns and distances from roads, with high-resolution sampling of soil profiles. Concentrations of soil Cu, Zn, Pb and Cd were measured. The comparison of concentrations in surface soils with original values and their vertical distributions shows that soils within 150 m of the highway side are contaminated by heavy metals, with surface accumulation and possible movement down the profiles. The transferring depth of heavy metals was 10–30 cm. The contribution ratios of heavy metals were 1.0–30.5% in the surface at 30 cm, with the sequence of Cd &gt;&gt; Cu &gt; Zn &gt; Pb. The accumulation rates were 1.27–2.03 kg Cu ha−1 y−1, 2.44–5.27 kg Zn ha−1 y−1, 0.71–1.40 kg Pb ha−1 y−1 and 0.010–0.018 kg Cd ha−1 y−1 in soils within 50 m range. Furthermore, the accumulation of these metals varied with the traffic intensity, service years and land use patterns. Soils under forest have less heavy metal accumulation, which suggests a protective forest to set beside highways at a distance of at least 50 m to prevent soils from being contaminated.

Status of Heavy Metal in Organic Fertilizers in Main Tea Growing Regions of China

To provide guidance for the safe use of organic fertilizers and improve soil quality and tea safety, it is necessary to conduct systematic analyses of the heavy metal content of organic fertilizers applied in the main tea producing areas of China. In this study, we analyzed the heavy metal contents in organic fertilizer samples collected from 2017 to 2019. The risks of collected organic fertilizers from different areas and sources were calculated. The results showed that the average concentrations of ω(As), ω(Hg), ω(Pb), ω(Cd), ω(Cr), ω(Cu), ω(Zn), and ω(Ni) in the collected organic fertilizers were 4.60, 0.22, 27.1, 0.78, 27.9, 58.3, 250.1, and 16.3 mg·kg-1, respectively. According to the assessment standard in NY/T 525- 2021, the over-limit rates of As, Hg, Pb, Cd, and Cr were 6.19%, 1.33%, 4.42%, 4.42%, and 1.33%, respectively. With respect to the area, the qualified rates were 100% in Shaanxi, Jiangsu, Anhui, Fujian, and Guangxi; 80%-90% in Shandong, Zhejiang, Hubei, Sichuan, Yunnan, and Guangdong; and only 54.5% in Jiangxi. The qualified rates of sources were 100% in rapeseed cake, soybean cake, and pig manure; 95.8% in sheep manure; 91.7% in cow manure; 90.7% in chicken manure; 87.2% in manure of other animals; 82.4% in the mixture of plant and animal sources; 65.2% in other plant sources; and 63.6% in other sources. According to the recommended application rate, the accumulation rate of heavy metals in soil with pig manure, cow manure, chicken manure, and sheep manure would be much higher than that with rapeseed cake and soybean cake. The average accumulation rate of organic fertilizer from animal sources was 7-30 times higher than that from plant sources. Therefore, it is recommended to use rapeseed cake or soybean cake fertilizer in tea plantation and to increase the supervision of heavy metal accumulation in soil and tea in those high-risk areas.

High nitrogen addition after the application of sewage sludge compost decreased the bioavailability of heavy metals in soil

Nitrogen (N) fertilizer is highly significant in agricultural production, but long-term N addition causes changes in quality indicators, such as soil organic matter (SOM), thus affecting the absorption and accumulation of organic pollutants. Therefore, paying more attention to organic fertilizers in the development of green agriculture is necessary. However, the accumulation of heavy metals (HMs) contained in organic fertilizers (especially sewage sludge compost (SSC)) in the soil can cause environmental contamination, but how this cumulative reaction changes with the long-term N addition remains unclear. Here the SSC impact on the bioavailability of five typical HMs (cadmium–Cd, chromium–Cr, copper–Cu, lead–Pb and arsenic–As) in the soil-plant system before and after SSC application was demonstrated through a field study in soils with different application rates of 0, 100 and 300 kg N ha−1yr−1, respectively. Our results showed that SSC application increased the concentration of most HMs in soil profiles and plant systems (wheat roots and grains), but the accumulation rate of HMs and most bioaccumulation values (BAC–bioaccumulation coefficient and BCF–bioconcentration factor) in plant systems were both lower in high-N addition soil than that in the low-N group. Moreover, speciation distribution results further indicated that SSC application increased the LB (liable available form, including F1–water soluble, F2–ion exchangeable, and F3–bound to carbonates) form of HMs and decreased the PB (potentially available form, including F4–humic acids and F6–fraction bound to organic matter) form of HMs in high-N addition soil, respectively. Those results suggested that HM bioavailability in high-N addition soil was lower than that in low-N addition soil when applied with SSC. Overall, this study found that increasing soil N content can inhibit the bioavailability of HMs when applying SSC, providing suggestions for optimizing the trialability and risk assessment of SSC application.

Estimation of the accumulation rates and health risks of heavy metals in residential soils of three metropolitan cities in China

Heavy metal concentrations in urban soils are likely to increase over time because of continuous urbanization and heavy metal emissions. To estimate the accumulation rates of heavy metals in urban soils, we collected soil samples from residential areas with different building ages in the metropolitan cities of Shanghai, Shenzhen, and Beijing, China. Heavy metal concentrations in the soils varied among the cities and were primarily affected by soil parent material and the intensity of anthropogenic sources. Regression analyses revealed that the accumulation rates of Cd and Cu in the soils ranged from 0.0034 to 0.0039 mg/(kg•year) and 0.343 to 0.391 mg/(kg•year), respectively, and were similar across the three cities, while accumulation rates of Zn and Pb in Shanghai were higher than those in Shenzhen and Beijing. The higher accumulation rates of Zn and Pb in Shanghai can be explained by differences in city history and industrial structures among the cities. Residential soils with high health risks posed by the heavy metals were mostly collected from old towns of Shanghai because of high Pb content in the areas. Although recent urbanization resulted in elevated concentrations of Cd, Cu, Zn, and Pb in the residential soils, the effect on the total health risks of residents exposed to the soils was negligible.

The influence of soil microorganisms on heavy metal content in the substrate of waste rock dumps

The environmental effects of mining and its impact on natural resources are of a holistic nature. One of the modern methods employed for the remediation of technogenically disturbed soils is the application of microorganisms. This paper studies the impact made by soil microorganisms on the accumulation rate of heavy metals in the substrate of waste rock dumps in the process of soil reclamation. Suspensions of soil microorganisms (microorganisms utilising mineral nitrogen forms / MUMN; microorganisms decomposing silicates / MDS; microscopic fungi / MF) were applied to the rock dump surface. Separate groups as well as their combinations were applied. The heavy metal content analysis did not indicate a significant exceedance of the maximum allowable concentration limits (MACL) in the soil of the waste rock. The only metal whose content exceeded the maximum admissible concentration limits was nickel. It has found that the application of microorganisms influences the concentration of several heavy metals due to pH level changes of the rock dump soil.

Phytoremediation of selected heavy metals using Bryophyllum daigremontianum (Raym-Hamet &amp; H. Perrier) A. Berger

Heavy metals are hazardous to plants as well as to humans. The purpose of the current work was to explore the phytoextraction potential of B. daigremontianum (Raym.-Hamet &amp; H. Perrier) A. Berger for the uptake of cadmium (Cd), nickel (Ni) and zinc (Zn) through roots, leaves and stem. B. daigremontianum grown in the contaminated soil showed relatively higher values for the uptake of Cd, Ni and Zn as compared to those grown in control soil. However, the accumulation rate of heavy metals was arranged in the order: Zn, Ni and Cd in root &gt; leaf &gt; stem. There was a significant difference at p &lt; 0.05 from their relevant control. Bioconcentration factors (BCF root) values clearly show the differences of heavy metals in control and contaminated plants which were 1.0106, 0.8306 and 0.6652, indicating the uptake in the order Zn &gt; Ni &gt; Cd. B. daigremontianum used for the Phytostabilization of Zn because the BCF value of the plant for this metal is greater than one.

Using a phytoremediation approach to treat Egyptian watercourses with heavy metal contamination

In this study, Potamogeton nodosus has a powerful ability of nutrient concentrations, and heavy metals uptake from the surrounding contaminated sediments and water in River Nile and Ismailia Canal was investigated. Ismailia Canal distributed stations uniformly (Shubra El-Kheima: S1–S3), and River Nile (El-Qursaya Island: S4–S6) of Egypt was selected. In each field station sampling, two sampling collection stations were selected; where P. nodosus sample collection along with contiguous sediments and water samples was conducted. The biomass of P. nodosus decreased with increasing distance from the discharge points S1 and S2 in Ismailia Canal to S3 and also in River Nile at El-Qursaya Island (S4) to S6. No significant difference was recorded between the biomass of P. nodosus in S2 and S3 on the one hand and S4 and S5 on the other hand. Significantly higher nutrients (N, P, K, Zn, and Cu) River Nile concentrations were recorded at El-Qursaya Island (S4) than at Ismailia Canal (S1 and S2) stations. Plant heavy metal accumulation rates (Fe and Mn), (Zn and Cu), and (Ni and Cd) in plant samples examined showed the same concentration pattern in the studied stations. Besides, the bioaccumulation factor (BAF) was above one for all the considered heavy metals; this confirms the high efficiency of metals uptake from the environment. Significantly positive correlations were recorded for all the plants, heavy metal, and sediments. The recorded high BAFs values may refer to the high ability of the studied plants to concentrate heavy metals, which suggested its use as an accumulator plant.

Simulation of the Absorption, Migration and Accumulation Process of Heavy Metal Elements in Soil-crop System

Soil-crop system is an important way that heavy metals harm the ecological environment and human health. To research and understand the process of heavy metal absorption, migration and accumulation in soil-crop system is important for the prevention and control of heavy metal pollution and the health of human beings. In this paper, we established a model for crop uptake of heavy metals to calculate the heavy metals contents of wheat roots, stems, leaves and grains, and we analyzed the accumulation process of heavy metals in roots, stems, leaves and grains in the growth cycle of wheat. The predicted values were compared with the measured values to test the accuracy of the model. The results demonstrated that different parts of wheat had different heavy metal absorption capacity, the absorption of the roots was the strongest, followed by leaves, and the absorption capacity of stems and grains was weak. In addition, the contents of different heavy metals in each part of wheat were also significantly different. The content of Cu was the highest, followed by Ni, while the contents of Pb and Cd were small. In the process of wheat growth, the heavy metal accumulation rate of stem, leaf and grain began to slow down at 90, 60 and 100 days respectively, and the concentration of heavy metals reached the maximum gradually, while the accumulation rate of heavy metals in roots showed a growing trend. We studied the process of absorption, migration and accumulation of heavy metals in soil-crop system by using numerical simulation technology, which can provide scientific basis for preventing the ecological and health risks of heavy metal pollution.

Assessment of the irrigation feasibility of low-cost filtered municipal wastewater for red amaranth (Amaranthus tricolor L cv. Surma)

Because of the scarcity of clean water, treated wastewater potentially provides an alternative source for irrigation. In the present experiment, the feasibility of using low-cost filtered municipal wastewater in the irrigation of red amaranth (Amaranthus tricolor L cv. Surma) cultivation was assessed. The collected municipal wastewater from fish markets, hospitals, clinics, sewage, and kitchens of households in Sylhet City, Bangladesh were mixed and filtered with nylon mesh. Six filtration methods were applied using the following materials: sand (T1); sand and wood charcoal consecutively (T2); sand, wood charcoal and rice husks consecutively (T3); sand, wood charcoal, rice husks and sawdust consecutively (T4); sand, wood charcoal, rice husks, sawdust and brick chips consecutively (T5); and sand, wood charcoal, rice husks, sawdust, brick chips and gravel consecutively (T6). The water from ponds and rivers was considered as the control treatment (To). The chemical properties and heavy metals content of the water were determined before and after the low cost filtering, and the effects of the wastewater on seed germination, plant growth and the accumulation rate of heavy metals by plants were assessed. After filtration, the pH, EC and TDS ranged from 5.87 to 9.17, 292 to 691µScm−1 and 267 to 729mgL−1, respectively. The EC and TDS were in an acceptable level for use in irrigation, satisfying the recommendations of the FAO. However, select pH values were unsuitable for irrigation. The metal concentrations decreased after applying each treatment. The reduction of Fe, Mn, Pb, Cu, As and Zn were 73.23%, 92.69%, 45.51%, 69.57%, 75.47% and 95.06%, respectively. When we considered the individual filtering material, the maximum amount of As and Pb was absorbed by sawdust; Cu and Zn by wood charcoal; Mn and Cu by sand and Fe by gravel. Among the six filtration treatments, T5 showed the highest seed germination (67.14%), similar to the control T0 (77.14%). The healthy plants/pot ratio (93.62%) was significantly higher for T5, even higher than the control (85.19%). Additionally, the average plant height for T5 (8.097in.) was statistically identical to the control (8.633in.). The average number of leaves for T5 (10) was near to the control (12). Finally, the minimum amount of heavy metals accumulated in the plants of T5, whereas the maximum accumulation rate varied among treatments. The accumulated levels of Fe, Mn, Cu, and Zn were within the safe limit; however, the concentrations of Pb and As exceeded their safe limits. The results showed that the low-cost filtration method potentially allows municipal wastewater to be used in irrigation for agricultural production.

Heavy metal bioaccumulation by the bryophyte Scleropodium purum at three French sites under various influences: rural conditions, traffic, and industry

An active biomonitoring of the heavy metals pollution experiment was undertaken by means of the bryophyte species Scleropodium purum transplanted at three different sites exposed to rural, traffic, or industrial influences. Concentrations of about 40 elements in S. purum were determined by instrumental neutron activation analysis and inductively coupled plasma mass spectrometry. Accumulation rates of heavy metals were determined in the three sites. These accumulation rates in polluted sites were matched together and also to those recorded at the rural site. The changes of the accumulation rate of heavy metals in S. purum versus their concentrations in PM(10) particles simultaneously collected above show some different accumulation properties of S. purum according to elements and sites. S. purum has a weak efficiency in the three sites to accumulate elements like V, Cr, Cu, Zn, As, Se, Sb, and Pb originating from atmospheric hot sources generally enriched in particulates matter (PM(10)), whereas it is particularly high for Br, Th, and Rb. For other elements, Co, La, Ce, and Hf, and rare earth elements, Fe, Sr, Nb, Ti, Al, and Sc, the collection efficiency by S. purum is intermediate. In the industrial site Dunkerque, a magnification of the collection efficiency by S. purum for elements originating from steel and aluminum productions and petroleum refinement suggests that these metals could be enriched in coarse particles with a better accumulation by the bryophyte with respect to PM10.

Heavy metal accumulation in calcareous soil and sorghum plants after addition of sulphur-containing waste as a soil amendment in Turkey

The purpose of this work was to evaluate the effect of sulphur containing industrial waste with respect to heavy metals on calcareous clay soil and sorghum (Sorghum bicolor L.) plant, as soil amendment. Pot experiment was established with a rate of 0, 20, 40, 60 t ha−1 air dry waste and 0.5, 1.0, 1.5 t ha−1 elemental sulphur and 0.5 t ha−1 sulphur + 20 t ha−1 waste. The use of waste on the soil with high CaCO3 and clay content did not create heavy metal (Ni, Cr, Co and Cd) build-up or toxicity. Even after the application of the high level of waste, it could not be seen any important toxic element accumulation in sorghum plant. Although the sulphur-rich waste, approximately up to 1 million t in the vicinity of Keçiborlu Sulphur Factory Isparta/Turkey, can be considered as amendment product for reclamation of saline-sodic and calcareous soils common in Turkey and other countries, repeated waste applications would result in different heavy metal accumulation rates. Therefore, it is needed to be examined with long term field experiments and different crops.

Accumulation Rates of Airborne Heavy Metals in Wetlands

Accumulation rates of heavy metals (Cd, Cr, Cu, Mn, Pb, and Zn) retained in wetland sediments in northwest Indiana—downwind of the Chicago-Gary-Hammond industrial area—are quantified to assess anthropogenic influences on atmospheric fluxes. Metal concentrations for 22 sediment cores are determined by ICP-AES after ashing and strong acid extraction. Relations between organic content and metal concentrations at depth are used to separate natural and anthropogenic sources. Accumulation rates over the lifetime of the wetlands (~4500 years) have averaged 0.2 (Cd), 1.4 (Cu), 1.7 (Cr), 13.4 (Mn), 4.8 (Pb), and 18.7 (Zn) mg m-2 y-1. Rates for the last 100 years have increased on average by factors of 6 (Cd), 8 (Cu), 10 (Mn), 15 (Pb), and 30 (Zn), remaining effectively constant for Cr. Where the wetlands have been drained, metals have been lost from the sediments, owing to changes in organic content and local hydrochemistry (exposure to acidic rainfall). Sediment-based accumulation rates at the undrained sites are higher, though generally consistent, with measured and modeled atmospheric fluxes documented by short-term studies conducted over the last three decades. The fraction of the total metals in the wetlands estimated to be of anthropogenic origin ranges from approximately 3% for Cr, up to approximately 35% for Pb, and 70% for Zn. This historic legacy of contamination must be considered in land management decisions, particularly when wetlands are drained.

Accumulation rates and mass calculations of Zn and Hg in recent sediments, Göta älv estuary, Sweden

Sediment masses and heavy-metal accumulation rates for the recent deposits of the Gota alv estuary were calculated using a GIS. Total masses of 4,000 t Zn and >20 t Hg were recorded, of which 367 t Zn and >0.72 t Hg occur in the inner estuary, the Goteborg harbour, and 3,657 t Zn and 19 t Hg are in the outer estuary, suggesting a high trapping efficiency of the estuary. The accumulation rates are 5 g m–2 year–1 Zn and 0.01 g m–2 year–1 Hg in the harbour, and 1.5 g m–2/year–1 Zn and 0.007 g m–2 year–1 Hg in the outer estuary. The Zn and Hg accumulation rates are highest close to the outlet of a sewage treatment plant, and decrease by a factor of 5 for Zn, and a factor of 2 for Hg in the outer estuary. The accumulation rates in the outer estuary decrease after 1980 A.D.

Geochemical records of sediments in the Eastern Gotland Basin—products of sediment dynamics in a not-so-stagnant anoxic basin?

Geochemical data from 4 cores taken in the Eastern Gotland Basin of the Central Baltic Sea (68 to 243 m water depth) show that depositional conditions for heavy metals in sediments were similar at all water depths prior to anthropogenic influxes. After the onset of industrialization, the deep anoxic parts of the basin expanded at irregular intervals and the <63 μm fractions of the sediments became characterized by high organic C and heavy-metal accumulation rates. The difference between the enrichment patterns in the basin and on the slope suggests that material enriched in organic matter (and associated trace elements) and in sulphides (and associated trace elements) is preferentially deposited in the basin. The composition of the sediments in the basin therefore reflects the effects of lateral transport of the sediment, which enriches organic C in the deepest part of the basin and of anoxia in the deep water of the basin, where metal sulphides are formed. Previous estimates of the timing of the onset of industrial pollution in the Central Baltic may have been in error because these new data suggest that this began in the Eastern Gotland Basin in about 1870.

Accumulation of Airborne Trace Pollutants by Arctic Plants and Soil

Plant and soil samples from 4 locations in Spitsbergen (Norway) were analysed for major ions, heavy metals, polyaromatic hydrocarbons (PAH) and chlorinated pesticides. The results indicate that trace amounts of these substance groups result from a number of different sources, namely from subsoil material, local emissions and long range atmospheric transport. A comparison of inorganic and organic micropollutant concentrations allows a distinction between trace substance uptake from soil or air. The correlation of plant and air concentrations makes it obvious that elevated accumulation rates of heavy metals in plants result from low level transport of particles. PAH are very effectively retained by species with large surface areas and represent particle concentrations in the air. Benzohexachloride in plants results from precipitation water rather than from direct uptake of gaseous traces.

Mid-Cretaceous Black Shales: A Result of Excessive Fertility or Global Anoxia?: ABSTRACT

In Holocene marine environments, organic carbon accumulation rates are high in areas of high productivity, rapid deposition, and in anoxic basins. Heavy metal accumulation rates are high in areas of high bulk sedimentation (resulting from the large detrital component), in areas of high fertility (heavy metal enrichment in organic tissue), and in areas of hydrothermal activity. The various environments can be characterized by the relations between their bulk sedimentation rates, amounts and types of organic carbon in the sediment, organic carbon accumulation rates, primary productivity, preservation factors (fraction of organic carbon fixed in the photic zone that becomes buried in the sediment), and accumulation rates of heavy metals (such as Cu, Ni, Zn). Differences in t ese relations exist, in particular, between areas where sapropel deposition is due to high supply (i.e., high fertility in localized upwelling areas) and where it is due to anoxic deep waters (such as in the Black Sea). Application of an improved calcareous nannofossil biochronology to compute accumulation rates in various DSDP sections show that the mid-Cretaceous black shales are characterized by substantially higher accumulation rates of heavy metals relative to organic carbon than is observed in Holocene upwelling settings. The implied widespread deep-water anoxia suggests high organic carbon preservation factors and correspondingly low primary productivity for large parts of the mid-Cretaceous oceans. End_of_Article - Last_Page 552------------