Extraction Of Heavy Metals Research Articles

Exploring Strategies Post-Revocation of Licensing Exemption for Malaysia's Tailing Processing Industry

The extraction of heavy metals and rare-earth elements from tailing residue has caused a significant impact towards the environment as well as the industrial workers as a result from the contamination caused by the processing activities. The radionclide concentration of 226Ra, 232Th, and 40K in soil and tailing residue were found to be within the range of 0.31 - 4.97 Bqg-1 and 1.24 - 4.47 Bqg-1, 0.16 - 11.07 Bqg-1 and 1.08 - 8.56 Bqg-1, 0.22 - 1.24 and 0.18 - 1.32 Bqg-1, respectively. The radiological impack assessment findings indicated significant overexposure risks where the annual effective dose was estimated to be within the range of 0.7 – 207.6 mSvy-1 while the excess lifetime cancer risks we found to have exceeded the limit let by the local regulatory body. The correlation between study findings and the enactment of the licensing exemption order was done to identify the effects of non-regulatory compliance to the Atomic Energy Licensing Act. The study also emphasized on the remediation importance of industrial sites before implementing any form of changes towards new regulatory adherence. Hence, the study recommeneds potential remediation techniques but taking into account the operational status of each proceesing plant, degree of contation and possible future use of the contaminated site.

Enhancing the color shade and depth of linen fabrics dyed with Caesalpinia sappan L. wood extract using metallic salt mordants

This study demonstrated natural dyeing of linen with a dye extracted from sappan wood (Caesalpinia sappan L.). Four metallic salt mordants, namely (NH4)2Fe(SO4)2, CuSO4, SnCl2, and AlK(SO4)2, referred to as Fe, Cu, Sn, and Al, respectively, were used to improve the dyeing properties. The influences of the pH, dye concentration, mordant type and concentration, and mordanting technique on the dyeing properties were investigated. Dyeing without mordants resulted in a reddish-brown fabric; however, different mordants produced a variety of color shades. In general, the mordant containing Fe yielded the highest color strength, generating a dark gray color very close to black. Crimson and magenta fabrics were obtained using Sn, and pink fabrics were obtained using Al. The samples with the Cu mordant showed a dark and dull purple color. The color strength due to post-mordanting was higher than those due to pre- and meta-mordanting. Dyeing and mordanting increased the ultraviolet protection factor (UPF) of the fabrics. Only the fabrics post-mordanted with Fe exhibited good ultraviolet protection (UPF 15). The concentrations of extractable heavy metals (Fe and Cu) were also determined.

Potential of rice straw derived activated biochar to remove arsenic and manganese from groundwater: A cleaner approach in the Indo-Gangetic Plain

Heavy metal pollution in groundwater has become a public health concern due to its non-degradable and poisonous nature. Several research studies were conducted using various adsorbents to extract heavy metals from water. However, the removal of As and Mn using rice straw-derived activated biochar in a binary metal system was found to be limited. This study examined a comparative analysis of As and Mn adsorption by CO2-activated biochar derived from rice straw in a single and binary metal approach. Findings showed that the maximal sorption capacity of As and Mn in single metal systems was 18.26 and 12.18 mg g−1 and 8.51 and 5.42 mg g−1 in binary metal systems. PSO kinetic model (R2> 0.99) and Langmuir isotherm model (R2> 0.95) show good agreement with experimental data. The highest removal efficiency of As (99.53%) and Mn (96.23%) was achieved in naturally contaminated water (Sahibganj, India). Health risk assessment indicates chances of cancer (CR> 1 × 10−4 and HQ>1) in humans due to the high concentration of As (192 μg L−1). Water treated with 0.1 g activated biochar had lower CR and HQ values, and metal concentration was below the WHO safe drinking water standard.

Extractability and phytotoxicity of heavy metals and essential elements from plastics in soil solutions and root exudates

Plastic waste is increasing and is a serious environmental problem. Among the threats associated with plastics is the release of contaminants into the environment. This study aimed to evaluate the efficiency of metals release from plastics (low-density polyethylene (LDPE), polyethylene terephthalate (PET), and polypropylene (PP)) as affected by different soil solution types, artificial root exudates, and distilled water. The extent of metal release varied depending on the type of solution and plastic used. Metals were leached most effectively from plastics in soil solutions, followed by root exudates, and least effectively by distilled water. LDPE released the highest concentrations of Cu and Na into solution, PP released the greatest amount of Fe, and PET released the most Cr. The efficiencies of Mg and Zn release from the plastics (PP and PET) varied by solution type. Among the plastics studied, LDPE exhibited the strongest ability to adsorb metals, such as Fe, Cr, Mg, and Zn from soil solutions. The amount of metal released from the plastics was also dependent on pH, dissolved organic carbon (DOC) concentrations, and the electrical conductivity (EC) of the solutions. Moreover, plastic extracts were found to have negative effects on germination and growth in Lepidium sativum.

Enrichment of Cd, Cr, Pb and Biological Detoxification Strategies in Sewage Irrigated Soils

Aim: Long-term use of sewage-sludge and improper management of agricultural lands can lead to an elevated heavy metal concentration in the soil resulting in barren soil. The present investigation was carried out to study the influence of different soil characteristics on the enrichment of Cd, Cr and Pb and their detoxification strategies in sewage irrigated soil profiles of Prayagraj region, India. Methodology: Di-acid mixture method used for soil analysis. The clean filtrate was used for the estimation of the heavy metals (Cd, Cr and Pb) by Atomic Absorption Spectrophotometer (AAS) (AAnalyst600, Perkin Elmer Inc., MA, USA). Isolation and identification of Cd, Cr and Pb Detoxifying microorganisms were isolated from the sewage-irrigated soils by nutrient agar medium. Results: It was observed that surface soils contained higher amount of DTPA- extractable heavy metals (Cd 3.00-3.20 mg kg-1,Cr 5.20-6.40 mg kg-1 and Pb 6.80-7.20 mg kg-1) and these amounts along with CEC (26.10 Cmol (p+) kg-1) and organic carbon (OC) Content (0.58%) decreased with the depth of soil profiles. Among the tested microorganisms, the highest accumulation of heavy metals in the sewage irrigated soils was observed in Citrobacter spp. to the extent of Cd 13.2%, Cr 36%, and Pb 42%. However, the lowest accumulation was observed in Escherichia coli to the extent of Cd 1.2%, Cr 8.4%, and Pb 10.2%. Conclusion: The horizons A of the studied soil profiles contain almost 12% more Cd, 9.11% more Cr, and 52% more Pb as compared to the contents of horizons B. Biological detoxification system metal uptake is largely influenced by the availability of metals. The highest accumulation of heavy metals was observed in the order of Pb > Cr > Cd by the selected microorganisms in the order of Citrobacter spp. >Bacillus spp. > Pseudomonas aerugia > Rhizopus arrhizus > Escherichia coli, resulting in the detoxification of the metals in the sewage irrigated soils. GRAPHICAL ABSTRACT

Sorption of Lead, Zinc and Copper from Simulated Wastewater by Amberlite Ir-120 Resin

The presence of heavy metals in the environment is major concern due to their toxicity. In the present study a strong acid cation exchange resin, Amberlite IR 120 was used for the removal of lead, zinc and copper from simulated wastewater. The optimum conditions were determined in a batch system of concentration 100 mg/L, pH range between 1 and 8, contact time between 5 and 120 minutes, and amount of adsorbent was from 0.05 to 0.45 g/100 ml. A constant stirring speed, 180 rpm, was chosen during all of the experiments. The optimum conditions were found to be pH of 4 for copper and lead and pH 6 for zinc, contact time of 60 min and 0.35 g of adsorbent. Three different temperatures (25, 40 and 60°C) were selected to investigate the effect of adsorption temperature on heavy metals adsorption onto Amberlite IR. The equilibrium data were analyzed by the Langmuir and Freundlich isotherms. The thermodynamic parameters such as Gibbs free energy, enthalpy and entropy changes were calculated. Moreover, in order to understand the heavy metal extraction kinetics in the presence of Amberlite IR 120, the ion exchange kinetics was also studied. The ion exchange kinetics data were regressed by the pseudo first-order, second-order models. The results obtained show that the Amberlite IR 120 strong acid cation exchange resin performed well for the removal of lead, zinc and copper.

The migration and transformation mechanisms of heavy metals during molten salt cyclic thermal treatment of MSWI fly ash

Molten salt thermal treatment has been demonstrated to be effective in dissolving heavy metals in municipal solid waste incineration (MSWI) fly ash. However, the complex thermochemical reactions of various heavy metals during the process remain unclear. This study investigated the migration and transformation mechanisms of typical heavy metals during molten salt (NaCl-CaCl2) cyclic thermal treatment of fly ash at 600–750 °C, as well as the leaching characteristics and recovery methods of heavy metals in the reacted products. Molten chlorides could be recycled to extract heavy metals from fly ash, which reduced the leaching toxicity of heavy metals in the reacted slags. Over 64.3% of Cd, Cu and Pb in fly ash were transferred to molten salt while the migration rate of Zn was restrained to only 32.3% during the cyclic process at 750 °C. Regarding Cd, Cu, and Pb in molten salt, the chlorination and dissolution of their oxides were significant, while the combination of their chlorides with free O2– to form oxides precipitation was weak. However, the above reaction characteristics of Zn were the opposite. Furthermore, Zn2+ could be stabilized into hardystonite (Ca2ZnSi2O7) in molten salt by reacting with Si2O76- generated from the combination of O2– and SiO2. Besides, increasing the reaction temperature facilitated the chlorination and dissolution of heavy metals. For recovery, heavy metals could be concentrated on the insoluble matters of molten salt, with a maximum concentration of approximately 5 times that in fly ash.

Geochemical Assessment of the Modern Sediments of a Lake in the North of Russia

Core sediment (sapropel) samples were collected from Lake Okunozero, the Republic of Karelia, Russia, to assess the distribution of heavy metals and their main fractions, probable sources of pollution, and potential ecological and toxicological risks for the water body. Heavy metal concentrations were measured by the mass spectrometry method using an XSeries-2 ICP-MS. The sequential extraction of heavy metals from sapropel samples was performed using the scheme of Tessier. According to the Russian Interstate Standard (GOST), the sapropel of Lake Okunozero is suitable for use in agriculture. The exceedances of the regional background levels were detected only for Pb and Cd. In accordance with Pollution Load Index (PLI) and Potential Ecological Risk (RI), no ecotoxicological risk in researched sediments was found. A significant correlation between some investigated heavy metals was established. Most heavy metals were in the insoluble mineral phase (Mn et al.) or were associated with organic matter (Cu, Zn, Mo, Ni). Only Mn, Zn, Cd, and Pb were found in the available fraction from 13 to 24% of the total metal content in the sediments. Other metals were less associated with the available fraction.

Evaluation of the Efficiency of Nerium oleander in the Phytoremediation of Lead Pollution by using Humic Acid

A field experiment was conducted in the lath house of the Agricultural Research and Experiment Station of the College of Agriculture in the governorate of Kirkuk-Iraq for the period from 1/3/2022 to 1/9/2002, to evaluate the efficiency of N.Oleander L.Album Plenum in the phytoremediation of lead (Pb) contaminated soil by adding Humic acid with three levels (0,5,10) ml..pot−1 of soil directly, the design of the experiment used is R.C.B.D. The results of the mechanisms and indicators of the efficiency of the nerium oleander in the extraction of heavy metals showed that the oleander plant with the assistance of humic acid has a high ability to absorb and accumulate the lead element very effectively, and the concentration of 10 ml.pot−1 of humic increasing the concentration of the Pb in the shoot and root system (30.71, 16.83 PPM) respectively, however the concentration of lead in the control plants was (25.32 and 14.36 PPM) respectively. Translocation factor TF>1 for all humic concentrations (1.82, 1.88, 1.77), respectively, and this indicates the high ability of the oleander to absorb and accumulate heavy elements. The concentration of 10 ml.pot−1 of humic acid gave the highest value of the bioaccumulation factor (BAF) 0.85, however it was 0.64 in the control plant. The concentration of 10 ml.pot−1 of humic was also superior in giving the highest value of the concentration index (CI), which ranged 1.27, and 1.06 in the control plant.

Использование пеностекла (гранулированного) в очистке городских поверхностных сточных вод

Introduction. When purifying natural objects from heavy metals a decisive role is played by sorption technologies, for the development of which new kinds of sorbents are required. The aim of the study is to evaluate the sorption capacity of granulated foam glass in the treatment of surface wastewater (SW) from urbanized areas from heavy metals (on the example of Co, Cr, Cu, Fe, Ni, Pb and Zn). Materials and methods. Granulated foam glass was used as a sorbent. The sorbate was urban surface wastewater from the city of Chelyabinsk. The interaction in the sorbent-sorbate system was studied in laboratory conditions by the limited volume method of static sorption when the pollutants were in the liquid phase and brought into contact with a stationary sorbent. The contact time of the sorbent with the sorbate was varied from 3 to 168 hours and the ambient temperature from 0 to 20 °C. The structure and surface composition of the sorbents were studied using a JEOL JSM-6460LV scanning electron microscope with an attachment for micro X-ray spectral analysis. Changes in the sorbate composition during interaction with the sorbents were determined by atomic emission spectrometry on an OPTIMA 2100 DV spectrometer (Perkin Elmer). Hydrogen index was determined on a pH-meter microprocessor рН-150МИ. Results. The structure and surface composition of granulated cellular glass has been studied. The efficiency of sorption of granulated foam glass of heavy metals from urban surface wastewater has been revealed. Conclusions. The results show that the investigated granulated foam glass is an effective sorption material and allows the extraction of heavy metals (cobalt, chromium, copper, iron, nickel, lead, zinc) from urban surface wastewater.

Research of technologies for the extraction of heavy metals from industrial wastewater

The presence of heavy metals in the environment is mainly associated with anthropogenic human activity. These are ferrous and non-ferrous metallurgy, heavy industry, energy. Due to air pollution, heavy metals enter the soil and water.The first place among the polluters of the environment with heavy metals is electroplating industry, where two categories of effluents are formed: spent concentrated effluent sanddiluted washing waters. In reservoirs, heavy metals have the ability to accumulate in the bottom sediments and thus are a source of second air pollution. They are not capable of biodegradation, but are able to accumulate in system components, causing a toxic effect on the animal world, humans and microorganisms. Different heavy metals affect the environment and biota in different ways. They can cause malfunction of the kidneys, liver, pancreas, accumulate in various organs and bones, causing their dysfunction. The greatest danger is heavy metals – chromium, nickel, cadmium, zinc. Their persistence, toxicity, ability to bio accumulate and migrate through trophic chains pose a danger to the existence of hydrobionts, animals and, above all, human health. The authors offer technologies for cleaning wastewater from heavy metals: reagent technologies, bacterial purification technologies, as well as phytotechnologies. Proposed sewage treatment plants for the removal of heavy metals from wastewater. The pollution of surface water sources, human health and living organisms will depend on the reliable extraction of heavy metals from spent galvanic effluents.

N fertilizers promote abscisic acid-catabolizing bacteria to enhance heavy metal phytoremediation from metalliferous soils

Bacterial-assisted phytoextraction is an attractive strategy to enhance the phytoremediation efficiency of heavy metal (HM)-contaminated soils. In the present study, we investigated the synergistic effects of N fertilizers and abscisic acid (ABA)-catabolizing bacteria on the HM (Cd, Zn, and Pb) phytoremediation efficiency of Brassica juncea L. (B. juncea). Compared with Rhodococcus qingshengii (R. qingshengii) alone, urea, ammonium‑nitrogen (NH4+-N), and nitrate‑nitrogen (NO3−-N) fertilizers combined with R. qingshengii increased HM concentrations in B. juncea by 13.8 %–48.2 %, 44.2 %–54.4 %, and 59.4 %–113.6 %, respectively, and enhanced the biomass of B. juncea by 7.7 %–38.8 %, 10.9 %–29.5 %, and 19.9 %–46.8 %, respectively. Consequently, the bioconcentration factor increased by 3.4 %–30.9 % and the phytoextraction rate increased by 18.5 %–98.7 %. Treatment with NO3−-N showed the most significant effect. In structural equation modeling, R. qingshengii inoculation showed greater path coefficients with soil pH and ABA and indoleacetic acid concentrations of B. juncea than N fertilization, indicating that R. qingshengii contributed more to HM extraction efficiency than N fertilizers. Additionally, differences in the extraction rates of Cd, Zn, and Pb from B. juncea were reduced following N fertilization. In summary, synergistic R. qingshengii inoculation and N fertilization have substantial potential to enhance phytoremediation efficiency. Combined application of R. qingshengii and NO3−-N fertilizers is recommended.

Dithiocarbamate ligands as heavy metal expectorants from aqueous solutions

The uncontrolled concentrations of heavy metals introduced into the water sources need an effective method for their removal. The dithiocarbamate (dtc) ligands are the most popular precipitating agents used for the removal of metals from wastewater. Presently, two novel dtc ligands, one without methylene linker (K2L1) and the other with methylene linker (K2L2) were used for the removal of eight heavy metals ions including Fe2+, Co2+, Ni2+, Cu2+, Cd2+, Ag+, Zn2+ and Pb2+ from the aqueous solution. These dtc ligands contain acyl (NH-C = O) and S, S (thiolate) functional groups. The results indicated that the metal removal efficiency of both ligands was almost 100% at pH 4 and 7 and free of the linker effect and acyl functional groups but depends on the S, S binding sites. It exhibited a distinct selectivity for the removal of metal ions (Pb2+ ∼ Cu2+ ∼ Ag1+ > Cd2+ > Co2+ > Ni2+ > Zn2+ > Fe2+). The developed methods have the potential for the removal of heavy metals and can be used for other thiophilic metals that are water-soluble. HIGHLIGHTS Water treatment, contaminated by heavy metal ions. Synthesis and characterization of two novel dithiocarbamate ligands. Effect of methylene (-CH2-) linker of dithiocarbamtes on heavy metals extraction. pH and temperature effect on the extraction efficiency of ligands.

A preliminary study to explain how Streptomyces pactum (Act12) works on phytoextraction: soil heavy metal extraction, seed germination, and plant growth.

Streptomyces pactum (Act12) can both promote plant growth and strengthen heavy metal mobilization. Nevertheless, the mechanisms of how Act12 works during the phytoextraction process are still unknown. The present work investigated whether the metabolites produced by Act12 could influence the seed germination and the growth of potherb mustard and explored its mobilizing effect on soil cadmium (Cd) and zinc (Zn). The results showed that the germination potential and rate of potherb mustard seed treated with Act12 fermentation broth were 1.0- and 0.32-folds higher than those of control, probably due to the interruption of seed dormant stage. We also found that Act12 inoculation not only promoted the dry biomass (6.82%) of potherb mustard, but also increased the leaf chlorophyll (11.8%) and soluble protein (0.35%) production. The boosted seed germination rate under Act12 treatment (up to 63.3%) indicated that Act12 enhanced the resistance of potherb mustard seeds to Cd and Zn and alleviated their physiological toxicity. The generated metabolites during the Act12 fermentation posed positive impact on the availability of soil Cd and Zn. These findings bring new insight into the Act12-assisted phytoextraction of Cd and Zn from contaminated soils.

Heavy metals removal from soil/sediments washing effluents via biocompatible aqueous two-phase systems

The generation of high amounts of soil/sediment washing solutions is one of the main concerns faced in ex situ treatment techniques, so in the present research, we have demonstrated the suitability of an organic salt like sodium potassium tartrate to efficiently promote phase segregation in a model soil washing solution containing biodegradable non-ionic-surfactants (Tween 80 and Tergitol 15S9) and heavy metals (copper, zinc, and cadmium), after a preliminary screening of the demixing effect of different inorganic and organic salts like ammonium nitrate, ammonium acetate and sodium potassium tartrate. The aqueous two-phase systems were characterized in depth at room temperature by defining the immiscibility region and correlating the experimental data with three empirical equations, and the results were discussed in the light of a thermodynamic function like the Gibbs free energy of hydration. Then, the applicability to extract the abovementioned metal ions was researched after TLs determination, observing high heavy metals extraction percentage (over 80 % in some cases). The extraction process was included in the soil washing process at real scale and it was simulated by means of the software SuperPro Designer, that makes up a valuable tool to ease the analysis of the technical viability of the proposed strategy.

Selective extraction of heavy metals from sewage sludge via combined process of acid leaching and ion exchange resins adsorption: Optimization and performance evaluation

ABSTRACT Heavy metals (HMs) in sewage sludge (SS) are major obstacles that limit the land application of SS. Although the removal of HMs with acid leaching and cation exchange resins (CER) adsorption has been investigated, neither process alone could meet the simultaneous demand for efficient HMs removal and good preservation of nutrients. In this report, sulfuric acid (H2SO4) and acetic acid (AC) were used to dissolve HMs from the SS, and subsequent CER adsorption was conducted to selectively extract the HMs from acid leachate. With the addition of 5 mmol/L H2SO4, the maximum leaching efficiency of Ni, Cu, Zn and Fe were 64.0%±2.7%, 29.0%±3.7%, 98.4%±4.1% and 16.4%±0.3%, respectively. No significant inhibition effect of Fe in the leachate on the HMs adsorption with CER has been observed. The CER with sulfonate groups (R-SO3H) showed higher Ni, Cu and Zn adsorption efficiency than the CER with thioureido groups (R-SH) and carboxylic groups (R-COOH) in the acid leachate. The optimal operation condition with a combined usage of H2SO4 and R-SO3H is characterized by the advantages of high HM removal efficiency, affordable cost, and low energy consumption through the evaluation with the triangulation model.

Potency of Seawater Battery with NiHCF + C Cathode Paired to Wind Turbine for Generating Clean Electricity in Rural Area

Electricity supply becomes the main issue in every country, because most of them are not distributed well. Electricity deficit potentially threatens the society and hampers the economic growth due to lack of power capacity. At the same time, many areas has untapped renewable sources that possibly fulfill the electricity demand. In fact, renewable energy (RE) is more environmentally friendly compared to fossil fuels power plant. However, the RE intermittency remains a problem. The most promising solution comes from RE storage, one of them are seawater battery. Besides it does not depend on heavy metal extraction, in which claimed safer, seawater also has a maximum power density and more effective voltage efficiency. The utility of seawater battery possibly will be used as RE storage on wind turbines system in rural area so-called 3T. In this study, seawater battery applies NiHCF cathode. NiHCF intercalation of sodium is synthesized using a gellatic method. NiHCF is smoothed and blended with polyvinylidene fluoride and black carbon at 3.5 milliliters 1-metil-2-pyrrolidone. The NiHCF cathode has an advantage of a voltage discharge with a 60-86% range. Compared with RO battery, seawater battery have nearly twice as much efficiency as RO battery. It is also known in previous research that NiHCF cathode has a capacity at 75 kW. The seawater battery is composed in a three-part battery pack, namely C1, C2, and C3. The separator that is used between C1 and C2 is AEM, while between C2 and C3 is NASICON. Electricity flows from wind turbines that generates electricity and streams to the battery pack, then distributes to the user.

Application of zeolite based nanocomposites for wastewater remediation: Evaluating newer and environmentally benign approaches

The presence of heavy metal ions and emerging pollutants in water poses a great risk to various biological ecosystems as a result of their high toxicity. Consequently, devising efficient and environmentally friendly methods to decontaminate these waters is of high interest to many researchers around the world. Among the varied water treatment and desalination means, adsorption and photocatalysis have been widely employed. However, the discussion and analysis of the use of zeolite-based composites as adsorbents are somehow minimal. The porous aluminosilicates (zeolites) are excellent candidates in wastewater treatment owing to various mechanisms of pollutants removal that they possess. The purpose of this review is thus to provide a synopsis of the current developments in the fabrication and application of nanocomposites based on zeolite as adsorbents and photocatalysts for the extraction of heavy metals, dyes and emerging pollutants from wastewaters. The review goes on to look into the effect of weight ratio on photocatalyst, photodegradation pathways, and various factors that influence photocatalysis and adsorption.

Extraction of Heavy Metals from Washing Waters of Electroplating Industries and Calculation Method of Electrodeionization Apparatus

Extraction of Heavy Metals from Washing Waters of Electroplating Industries and Calculation Method of Electrodeionization Apparatus

Thiophene Functionalized Magnetic Covalent Organic Frameworks For Selective Extraction Of Trace Heavy Metals Followed By ICP-MS Detection

Thiophene Functionalized Magnetic Covalent Organic Frameworks For Selective Extraction Of Trace Heavy Metals Followed By ICP-MS Detection