scholarly journals Adsorption kinetics of hexavalent chromium on to natural red-earth: a laboratory simulated study

2019 ◽  
Vol 80 (6) ◽  
pp. 1118-1124
Author(s):  
Githmi Gayani Pathberiya ◽  
G. Y. Jayasinghe ◽  
Rohana Chandrajith
Keyword(s):  
Heavy Metals ◽  
Heavy Metal Contamination ◽  
Anthropogenic Activities ◽  
Solution Ph ◽  
Natural Sand ◽  
Homogeneous Surface ◽  
Adsorption Sites ◽  
Langmuir Isotherm Model ◽  
Red Earth ◽  
Monolayer Coverage

Abstract Heavy metal contamination of water is a significant threat to organisms and to public health. Among them, chromium is one of the important heavy metals in the environment that originates mainly from anthropogenic activities. Natural red earth (NRE), a ferrous-coated natural sand, is one of the materials that could be used to remove heavy metals from contaminated water. Laboratory-scale simulated experiments were carried out to identify the retention behavior of Cr(VI) on NRE. The effects of solution pH, initial Cr(VI) concentration, the amount of NRE used and the contact time were examined. Almost 63% Cr(VI) was adsorbed within 20 minutes. When particle size ranged from 125 to 180 μm, the Cr adsorption data followed the Langmuir isotherm model, providing a higher R2 value of 0.9523, suggesting monolayer coverage on the homogeneous surface with a uniform distribution of energetic adsorption sites. The monolayer coverage of Cr on NRE is estimated as 11.35 mg/g. The data showed that NRE can be used to remove Cr(VI) from aqueous solutions effectively, and this method is found to be simple, effective, economical and environmentally friendly.

Sorption of heavy metals in the biomass of alga Palmaria palmata

2013 ◽  
Vol 68 (7) ◽  
pp. 1543-1549 ◽  
Author(s):  
Małgorzata Rajfur ◽  
Andrzej Kłos
Keyword(s):  
Heavy Metals ◽  
Calcium Ions ◽  
Langmuir Isotherm ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Sorption Process ◽  
Palmaria Palmata ◽  
Constant Flow ◽  
Langmuir Isotherm Model ◽  
Conductivity Range

Sorption of heavy metals by the sea alga Palmaria palmata was investigated in laboratory conditions. The sorption process of the analytes was carried out with constant flow of the solutions through the algae samples. The Langmuir isotherm model was used to describe equilibria. The experiments confirmed that 50 min of exposure of algae with little heavy metal contamination in contaminated waters results in the increase of concentration of these analytes, proportional to their concentration in the tested waters. On the basis of the Langmuir isotherm direction factor, a = (c(a,max) × K)−1, affinity of heavy metals and algae increases in the following sequence: Mn2+ < Zn2+ ≈ Cd2+ < Cu2+, and the competitiveness of sorption of cations naturally present in the algae environment versus Zn2+ ions changes according to following sequence: Na+ < Ca2+ < H+, defined for the concentrations referring to the ion unit charge. It was also confirmed, that the presence of sodium and calcium ions in the solutions, within the conductivity range from 200 to 1,000 μS/cm, is not statistically significant for the sorption of heavy metals from these solutions.

scholarly journals The Preliminary Study for Effect of Plant Extract on Concentration of Heavy Metals in Soil

2021 ◽  
Vol 945 (1) ◽  
pp. 012065
Author(s):  
Li Na Lee ◽  
Xinxin Guo ◽  
Jinq Shiou Lim ◽  
Rou Hui Wong ◽  
Choon Aun Ng ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Plant Extract ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Anthropogenic Activities ◽  
High Energy ◽  
Liquid Form ◽  
Weight Percentage ◽  
Spiked Soil

Abstract Heavy metal contamination in soils had arisen into a more prominent problem as a result of increasing anthropogenic activities like manufacturing, mining, excessive application of agricultural chemicals and inappropriate disposal of wastes. Researchers across the globe had been striving to discover and develop methods to restore the soil back to its original condition with an assortment of remediation techniques that varies from treatment mechanism for various soil and contamination condition. Majority of the existing techniques have drawbacks like high energy consumption, specificity on the site condition, limitations on applicable contaminants, side effects after treatment, and also being uneconomical. More and more researchers are beginning to divert their attention into using organic stabilizers for treatment of soil heavy metal contamination in recent years after learning about its potential after numerous research showed promising reduction on the bioavailability and mobility of heavy metals. Due the lack of study on liquid-form organic stabilizers, the authors dedicated this research into implementing plant extract (TM) in the immobilization of heavy metals in soil. For comparison purpose, sodium alginate (SA), a proven organic stabilizer had been incorporated into the experiment to evaluate the performance of plant extract to immobilize cadmium (Cd), chromium (Cr), and manganese (Mn) from the metal-spiked soil samples in this research. The study findings suggested that the SA increased the unstable fractions, namely the exchangeable and carbonate fractions, of Cd relative to the untreated soil sample by 10.3 % to 5.2. On the other hand, the TM yields a result of 0.1 % to 1.1 % reduction of the unstable Cd. For the unstable Cr, both SA and TM decreased the concentration levels in the soil by 2.5 % to 8.0 % and 6.1 % to 7.9 % respectively. The results for Mn showed that the SA is able to decrease the concentration of its unstable fractions by 2.0 % to 7.5 % while the TM increases the concentration by 11.7 % to 1.5 %. In general, lower concentration of heavy metals in the unstable fractions was detected as the dosage of soil stabilizers applied increases. The application of soil stabilizers at 10 % weight percentage yields the lowest reading of unstable heavy metals in comparison with samples with lower dosage.

Sorption of Heavy Metal on Natural Clay

2018 ◽  
Vol 68 (12) ◽  
pp. 2804-2807
Author(s):  
Mircea Stefan ◽  
Adriana Bors ◽  
Daniela Simina Stefan ◽  
Ionut Alexandru Savu Radu ◽  
Cicerone Marinescu
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ion ◽  
Background Electrolyte ◽  
Hydroxyl Groups ◽  
Natural Clay ◽  
Equilibrium Isotherms ◽  
Solution Ph ◽  
Constant Ph ◽  
Langmuir Isotherm Model

Sorption of heavy metals on Na-montmorillonite was studied as a function of solution pH and different concentrations of background electrolyte and also a function of added metal ion at constant pH. Equilibrium isotherms have been measured and analyzed using a Langmuir isotherm model. The metal ions were predominantly adsorbed on the permanent charge sites in a easily replaceable state. There was also evident a substantial involvement of the hydroxyl groups on the edges of Na-montmorillonite in specific adsorption of the cations especially at higher pH.

Risk Implications of Heavy Metal Contamination in Agricultural Soil and Crop Productivity

2018 ◽  
pp. 238-258
Author(s):  
Archana ◽  
Ajai Kumar Jaitly
Keyword(s):  
Heavy Metals ◽  
Contaminated Soils ◽  
Metal Contamination ◽  
Agricultural Soil ◽  
Heavy Metal Contamination ◽  
Agricultural Soils ◽  
Anthropogenic Activities ◽  
Crop Productivity ◽  
Cobalt Chromium ◽  
Lead Nickel

Heavy metals especially lead, nickel, cadmium, copper, cobalt, chromium and mercury are more toxic and chief contaminants of the environment. Agricultural soils in many parts of the world are slightly to moderately polluted with heavy metals due to increase in geologic and anthropogenic activities (use of phosphate fertilizers, sewage sludge application, dust from smelters, industrial waste). Plants growing on these contaminated soils showed toxicity symptoms that results in reduce growth and activity which declined the productivity and posing threats to agro-ecosystems. They put plants under stress and affect their physiology. In this chapter, we have summarized the effects of heavy metals on plants including both symptoms and productivity.

HEAVY METALS IN FOOD CROPS: IDEAL SOURCES AND ROLES OF URBAN AGRICULTURE IN FACILITATING THEIR CONSUMPTION- A REVIEW

2021 ◽  
Vol 5 (2) ◽  
pp. 34-45
Author(s):  
N. Abdullahi ◽  
E. C Igwe ◽  
M. A. Dandago ◽  
N. B. Umar
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Urban Areas ◽  
Agricultural Soil ◽  
Heavy Metal Contamination ◽  
Anthropogenic Activities ◽  
Wastewater Irrigation ◽  
Food Crops ◽  
Urban Food Production ◽  
Soil And Water

The qualities of agricultural soil and water are diminishing continuously due to the rigorous anthropogenic activities currently stocking the soil with a lot of toxic chemicals including heavy metals. Heavy metals are highly persistent and non-biodegradable, control of their contamination is very tricky to handle. Their presence in soil and water is detrimental to food crops and humans. Various sources of heavy metals contaminants and the role of urban food production on human heavy metal contamination were discussed.Heavy metals have their way into the soil and food crops through wastewater irrigation and production in contaminated soil. The habitual heavy metals contamination sources for food crops are wastewater irrigation, abuse of agrochemicals, production in the contaminated field, atmospheric deposit when foods are exposed to contaminated air, and unethical mining activities. Agricultural soil in urban and peri-urban areas are heavily contaminated with heavy metal due to various anthropogenic activities. Wastewater irrigation intensify the contamination by supplying the soil with more heavy metals. The heavy metals are passed to food during production and subsequently to humans after consumption.

scholarly journals Heavy metal toxicity in agricultural soil due to rapid industrialization in Bangladesh: a review

2018 ◽  
Vol 6 (1) ◽  
pp. 83 ◽  
Author(s):  
Ram Proshad ◽  
Tapos Kormoker ◽  
Niaj Mursheed ◽  
Md. Monirul Islam ◽  
Md. Isfatuzzaman Bhuyan ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Contamination ◽  
Agricultural Soil ◽  
Toxic Elements ◽  
Soil Microorganisms ◽  
Heavy Metal Contamination ◽  
Anthropogenic Activities ◽  
Industrial Area ◽  
Rapid Industrialization

Heavy metal is a member of loosely defined subset of elements that exhibit metallic properties. It mainly includes the transition metals, some metalloids, lanthanides, and actinides. Heavy metals are ubiquitous in the environment, as a result of both natural and anthropogenic activities. They are stable and cannot be destroyed, and therefore tend to accumulate in the environment. In recent years, there has been a substantial concern over the extent of contamination of the environment with toxic elements. Soil pollution caused by rapid industrial activities has become a worrisome phenomenon due to its impact on soil and environment. Heavy metal pollution in soil arising from industrial discharges significantly poses a great threat to the environment. Heavy metals come to the soil by several ways and the soil becomes toxic which cause serious problem to the environment. In toxic soil, microorganisms cannot persist and there create an imbalance situation in the soil. The main objective of this study was to assess the problem of heavy metal contamination in industrial area soil in Bangladesh with environmental risk assessment.

scholarly journals Measures of Harm from Heavy Metal Pollution in Battery Technicians’ Workshop within Ilorin Metropolis, Kwara State, Nigeria

2019 ◽  
Vol 2 (2) ◽  
pp. p73 ◽  
Author(s):  
Henry Olawale SAWYERR ◽  
Morufu Olalekan RAIMI ◽  
Adedotun Timothy ADEOLU ◽  
Oluwaseun Emmanuel ODIPE
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Contamination ◽  
Anthropogenic Activities ◽  
Negative Relationship ◽  
Pollution Index ◽  
Long Term Effects ◽  
Normal Ranges ◽  
Significant Negative Relationship ◽  
Slight Contamination

Soil pollution with Heavy Metals (HMs) has been of much interests lately and is one of the major issues to be faced globally and requires attention because heavy metals above their normal ranges are extremely threatened to both biotic and abiotic life. It was therefore of interest to conduct study to assess the extent of heavy-metal contamination of soils within battery technicians’ workshops within Ilorin metropolis, Kwara State, Nigeria. A total of twenty-five composite soil samples were collected from six selected battery charger workshop within Ilorin metropolis and analyzed for the presence of heavy metals using atomic absorption spectrophotometer. Result reveals significant positive relationship between Mn and Fe (r=0.511**, p<0.001), Mn and Cu (r=0.565**, p<0.001), Fe and Cr (r=0.895**, p<0.001), Fe and Cu (r=0.823**, p<0.001) and between Cr and Cu (r=830**, p<0.001). Result also shows significant negative relationship between Mn and Cr (r=-0.679**, p<0.001), Pb and Cu (r=-0.468*, p<0.05) respectively. The pollution status of heavy metals in soils was evaluated using quantitative indices (pollution index–PI). The result shows that Zn was moderately contaminated while other heavy metals (Pb, Cd, Cr and Cu) had very slight contamination (pollution index<0.1). The Ilorin metropolis soils of Kwara State were found to have a moderate to very slight contamination respectively. Large variations in PI values of Zn revealed that soil in those areas of the city, which are influenced by anthropogenic activities, have moderate concentrations of Zn resulting in “considerable risk”. The findings of this study recommend comprehensive continuous annual monitoring and auditing and further studies on the level of these heavy metals in the near future to ascertain long-term effects of anthropogenic impact is forestalled to protect the men and the environment. This should also involve larger coverage with studies on ground water around such locations. Furthermore, continuous metals speciation should be carried out so that the form and extent of metal bioavailability can be evaluated further.

scholarly journals Heavy metal remediation technologies in Latvia: possible applications and preliminary case study results / Technologie remediacji obszarów zanieczyszczonych metalami ciężkimi na Łotwie: możliwe zastosowania i wstępne wyniki badań

2012 ◽  
Vol 19 (4) ◽  
pp. 533-547
Author(s):  
Juris Burlakovs ◽  
Magnuss Vircavs
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Contamination ◽  
Anthropogenic Activities ◽  
Residential Areas ◽  
Territorial Planning ◽  
Heavy Metal Remediation ◽  
Study Results ◽  
Polluted Sites

Abstract Environmental contamination with heavy metals as a result of anthropogenic activities is not a recent phenomenon. Contaminated sites with heavy metals can be found in functioning as well as abandoned industrial (brownfield) territories, landfills, residential areas with historical contamination, road sides and rarely in polluted sites by natural activities. Pollution data on its amount and concentrations is known from historical studies and monitoring nowadays, but it should be periodically updated for the use of territorial planning or in case of a change of the land use. A special attention should be paid to heavy metal contamination, because in many cases this contamination is most problematic for remediation. 242 territories now are numbered as contaminated and fixed in the National Register of contaminated territories - at least 56 of them are known as contaminated with heavy metals in different amount and concentration. Legislative aspects are discussed as well as an overview of soil and groundwater contamination research and the possible remediation technologies in Latvia are given. Two case studies are described in order to give the inside look in pre-investigations done before potential start of heavy metal remediation works.

scholarly journals Accumulation of essential (copper, iron, zinc) and non-essential (lead, cadmium) heavy metals in Caulerpa racemosa, sea water, and marine sediments of Bintan Island, Indonesia

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 699
Author(s):  
Tengku Said Raza’i ◽  
Thamrin Thamrin ◽  
Nofrizal Nofrizal ◽  
Viktor Amrifo ◽  
Hilfi Pardi ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Sea Water ◽  
Anthropogenic Activities ◽  
Heavy Metal Concentration ◽  
Atomic Absorption Spectrophotometry ◽  
Caulerpa Racemosa ◽  
Mining Areas

Background: Heavy metals are materials naturally occurring in nature and increase with a rise in human activity. Ex-mining areas and domestic waste from human settlements are sources of heavy metal contamination that enter and pollute water, which then accumulates in various organisms including the Caulerpa racemosa community. The accumulation of heavy metals in C. racemosa has a wide impact on the food chain in aquatic ecosystems and humans because this alga is a consumptive commodity.   Methods: Sampling of C. racemosa was carried out at seven sites on Bintan Island, Indonesia covering the eastern (Teluk Bakau, Beralas Pasir, Malang Rapat), northern (Berakit and Pengudang), western (Sakera), and southern parts (Tg. Siambang). Sampling was carried out during different monsoons, and heavy metals in water and sediment samples were measured to determine the heavy metal concentration. Heavy metals were analyzed by a spectrophotometric method using Atomic Absorption Spectrophotometry.   Results: The results showed that heavy metal concentrations fluctuate according to changes in the wind season, which carry currents and spread pollutants into the water. The concentration of metal in the water is also from anthropogenic activities. The heavy metal content of cadmium (Cd), lead (Pb), copper (Cu), iron (Fe), and zinc (Zn) in C. racemosa is high in locations close to settlements. Meanwhile, in seawater samples, Fe and Zn metals have the highest concentrations compared to others.  Conclusions: Ex-bauxite mines are a source of Fe and Zn metal contamination in the environment, especially at Tg. Siambang. The levels of these heavy metals in the sediment are also high, as surface particle deposits accumulate at the bottom of the sediment. In general, the levels of heavy metals Cd, Pb, Cu, Fe, and Zn increase in the northern monsoon because the dynamics of the water transport greater heavy metal pollution.

Investigation of the Effect of Sorbent Dosage and Solution pH on the Adsorption Efficiency of Catfish- and Tilapia-Derived Hydroxyapatite

2016 ◽  
Vol 864 ◽  
pp. 123-127
Author(s):  
Astrid Ayla E. Liberato ◽  
Jarevic P. Cayabyab ◽  
Ma. Shanlene D.C. Dela Vega
Keyword(s):  
Heavy Metals ◽  
Raw Materials ◽  
Contaminated Water ◽  
Adsorption Efficiency ◽  
Solution Ph ◽  
Adsorption Sites ◽  
Naturally Occurring ◽  
Surrounding Environment ◽  
Adsorption Capacities ◽  
Sorbent Materials

The contamination of water by heavy metals is still a continuing threat to the surrounding environment and to the lives of those exposed to it. A group of techniques to remove ions from contaminated water may employ naturally occurring sorbent materials like hydroxyapatite (HA). HA was successfully extracted from waste fishbones of locally-sourced catfish and tilapia as shown by the diffractograms. The amount of ions removed from Pb2+ solutions at two pH levels using 30 and 60 mg HA powders were determined using Atomic Absorption Spectroscopy. Based on the data, increasing pH and HA dosage increased the adsorption efficiency for both types of HA. However, the saturation of HA has not been attained with calculated adsorption capacities decreasing further with sorbent dosage due to an increase in the number of adsorption sites for a limited amount of ions. Although the values obtained at this level are comparable for both catfish- and tilapia-extracted HA, further studies will be needed to measure their corresponding maximum adsorption capacities. With this investigation, wastewater treatment for lead (II) ion contamination may become more accessible using inexpensive raw materials.

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