The Development of an Automatic Molten Metal Supplier for an Aluminum Thermal Furnace

이준호 한국생산제조학회 2009 한국생산제조학회지 Vol.18 No.5

The objective of this development project is to localize an automatic molten metal supplier that has been distributed by WESTOMAT, Germany, throughout the world. To achieve this purpose, an energy-saving pressurized dosing furnace and molten metal differential pressure control system that is able to automatically supply a determined quantity of aluminum molten metal were developed. The localized equipment was installed in a site. Also, the results of the test operation of this equipment can be summarized as follows: It was able to improve the productivity because there were small decreases in supplying speeds and small losses in wastes compared to the existing mechanical molten metal supplier. Also, it was able to minimize the cost in maintenances due to the direct application of high temperature molten metals to molds. In addition, there were small energy losses due to the use of high thermal insulators compared to the existing reverberating furnace and able to prolong the life-time of furnaces and produce good quality nonferrous metals because it represented small carbon refractories and alumina in applied molten metals. Furthermore, it demonstrated no particular differences by objectively comparing it with the product by WESTOMAT. The objective of this development project is to localize an automatic molten metal supplier that has been distributed by WESTOMAT, Germany, throughout the world. To achieve this purpose, an energy-saving pressurized dosing furnace and molten metal differential pressure control system that is able to automatically supply a determined quantity of aluminum molten metal were developed. The localized equipment was installed in a site. Also, the results of the test operation of this equipment can be summarized as follows: It was able to improve the productivity because there were small decreases in supplying speeds and small losses in wastes compared to the existing mechanical molten metal supplier. Also, it was able to minimize the cost in maintenances due to the direct application of high temperature molten metals to molds. In addition, there were small energy losses due to the use of high thermal insulators compared to the existing reverberating furnace and able to prolong the life-time of furnaces and produce good quality nonferrous metals because it represented small carbon refractories and alumina in applied molten metals. Furthermore, it demonstrated no particular differences by objectively comparing it with the product by WESTOMAT.

Phytohormones enabled endophytic <i>Penicillium funiculosum</i> LHL06 protects <i>Glycine max L.</i> from synergistic toxicity of heavy metals by hormonal and stress-responsive proteins modulation

Bilal, Saqib,Shahzad, Raheem,Khan, Abdul Latif,Al-Harrasi, Ahmed,Kim, Chang Kil,Lee, In-Jung Elsevier Scientific Pub. Co 2019 Journal of Hazardous Materials Vol. No.

<P><B>Abstract</B></P> <P>This study investigates the stress-mitigating effects of endophytic <I>Penicillium funiculosum</I> LHL06 on soybean roots via modulation of physio-biochemical, molecular, and proteomic responses to combined heavy metal (Ni, Cu, Pb, Cr, and Al) toxicity. Preliminary screening revealed that LHL06 can tolerate and remediate combined heavy metal contamination in its media and upregulate gibberellins (GA1, GA3, GA4, GA7 and GA9) and indole-3-acetic acid (IAA) production. Inoculation of LHL06 resulted in marked reduction of metals uptake in roots and shoots by downregulating heavy metal ATPase genes (<I>GmHMA13, GmHMA14, GmHMA19)</I> and <I>GmMATE1</I> compared to non-inoculated plants; in turn, this decreased abscisic acid and jasmonic acid levels. Moreover, triggering of free amino acid metabolism in LHL06-inoculated roots significantly upregulated expression of stress-related proteins (glutathione S-transferase L3, isoflavone reductase-like, chalcone isomerase A, NAD(P)H dehydrogenase (quinone), FQR1-like 1 isoform X2, and Peroxidase 3) to combat metals toxicity. Compared to non-inoculated-plants, LHL06-inoculated-plants exhibited higher antioxidant activity and transcript accumulation of glutathione S-transferase (<I>GmGST8 and GmGST3</I>), <I>G6PDH</I>, and <I>GmSOD1[Cu-Zn]</I>, which decreased metal-induced reactive oxygen species. Therefore, LHL06-inoculation remediate combined metal contamination in soil, activate signaling network of stress-responsive hormones and antioxidant systems for promoting growth and tolerance, and reduce metal-accumulation, thereby making plants safer for consumption.</P> <P><B>Highlights</B></P> <P> <UL> <LI> LHL10 demonstrated significant resistance to heavy metals stress and produced higher gibberellins and indole-3-acetic acid. </LI> <LI> Association of LHL06 significantly alleviated negative effects of synergistic toxicity of heavy metals in soybean. </LI> <LI> Inoculated soybean demonstrated down-regulation of heavy metals transporters genes and illustrated reduced metals uptake. </LI> <LI> LHL06 increased Stress and defence-related proteins expression of soybean under synergistic heavy metals toxicity. </LI> <LI> LHL06-inoculated soybean exhibited lowered accumulation of endogenous hormones (ABA and JA) under stress. </LI> </UL> </P>

Bioaccumulation of heavy metals in maricultured fish, <i>Lates calcarifer</i> (Barramudi), <i>Lutjanus campechanus</i> (red snapper) and <i>Lutjanus griseus</i> (grey snapper)

Nasyitah Sobihah, Nasri,Ahmad Zaharin, Aris,Khairul Nizam, Mohammad,Ley Juen, Looi,Kyoung-Woong, Kim Elsevier 2018 CHEMOSPHERE - Vol.197 No.-

<P><B>Abstract</B></P> <P>Mariculture fish contains a rich source of protein, but some species may bioaccumulate high levels of heavy metals, making them unsafe for consumption. This study aims to identify heavy metal concentration in <I>Lates calcarifer</I> (Barramudi), <I>Lutjanus campechanus</I> (Red snapper) and <I>Lutjanus griseus</I> (Grey snapper). Three species of mariculture fish, namely, <I>L. calcarifer</I>, <I>L. campechanus</I> and <I>L. griseus</I> were collected for analyses of heavy metals. The concentration of heavy metal (As, Cd, Cu, Cr, Fe, Pb, Mn, Ni, Se, and Zn) was determined using inductive coupled plasma mass spectrometry (ICP-MS). The distribution of heavy metals mean concentration in muscle is Zn > Fe > As > Se > Cr > Cu > Mn > Pb > Ni > Cd for <I>L. calcarifer</I>, Fe > Zn > Cr > As > Ni > Mn > Se > Cu > Pb > Cd for <I>L. campechanus</I> and Fe > Zn > Cr > Ni > Se > Cu > As > Mn > Pb > Cd for <I>L. griseus</I>. Among all of the species under investigation, the highest concentration of Fe was found in the muscle tissue of <I>L. campechanus</I> (19.985 ± 1.773 mg kg<SUP>−1</SUP>) and liver tissue of <I>L. griseus</I> (58.248 ± 8.736 mg kg<SUP>−1</SUP>). Meanwhile, <I>L. calcarifer</I> has the lowest concentration of Cd in both muscle (0.007 ± 0.004 mg kg<SUP>−1</SUP>) and liver tissue (0.027 ± 0.016 mg kg<SUP>−1</SUP>). The heavy metal concentration in muscle tissue is below the permissible limit guidelines stipulated by the Food & Agriculture Organization, 1983 and Malaysia Food Act, 1983. The concentration of heavy metals varies significantly among fish species and tissues. <I>L. campechanus</I> was found to have a higher ability to accumulate heavy metals as compared to the other two species (p < .00). Among all the studied fish, liver tissue has a higher concentration of heavy metals compared to muscle tissue (p < .05). The findings from this study can serve as baseline information for future monitoring and risk assessment studies. Periodic monitoring of heavy metal concentration in mariculture fish must be performed to prevent acute and chronic food intoxication.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Species were chosen due to the most extensive maricultured species in estuaries. </LI> <LI> Species chosen were the most consumable fish species in Asian region. </LI> <LI> High metals concentration had been observed in <I>L. campechanus.</I> </LI> <LI> Liver tissues possessed higher metal concentration than muscle tissues. </LI> <LI> Studied metals were below than the permissible limit. </LI> </UL> </P>

Hydrometallurgical recovery of heavy metals from low grade automobile shredder residue (ASR): An application of advanced Fenton process (AFP)

Singh, Jiwan,Lee, Byeong-Kyu Elsevier 2015 Journal of environmental management Vol.161 No.-

<P><B>Abstract</B></P> <P>To investigate the leaching and recovery of heavy metals from low-grade automobile shredder residue (ASR), the effects of nitric acid (HNO<SUB>3</SUB>) and hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>) concentrations, liquid/solid (L/S) ratio, leaching temperature and ASR particle size fractions on the heavy metal leaching rate were determined. The heavy metals were recovered by fractional precipitation and advanced Fenton process (AFP) at different pHs. The toxicity characteristic leaching procedure (TCLP) test was also performed in the residue remaining after heavy metal leaching to evaluate the potential toxicity of ASR. The heavy metal leaching efficiency was increased with increasing HNO<SUB>3</SUB> and H<SUB>2</SUB>O<SUB>2</SUB> concentrations, L/S ratio and temperature. The heavy metal leaching efficiencies were maximized in the lowest ASR size fraction at 303 K and L/S ratio of 100 mL/g. The kinetic study showed that the metal leaching was best represented by a second-order reaction model, with a value of R<SUP>2</SUP> > 0.99 for all selected heavy metals. The determined activation energy (kJ/mol) was 21.61, 17.10, 12.15, 34.50, 13.07 and 11.45 for Zn, Fe, Ni, Pb, Cd and Cr, respectively. In the final residue, the concentrations of Cd, Cr and Pb were under their threshold limits in all ASR size fractions. Hydrometallurgical metal recovery was greatly increased by AFP up to 99.96% for Zn, 99.97% for Fe, 95.62% for Ni, 99.62% for Pb, 94.11% for Cd and 96.79% for Cr. AFP is highly recommended for the recovery of leached metals from solution even at low concentrations.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nitric acid combined with H<SUB>2</SUB>O<SUB>2</SUB> greatly increased the leaching of metals from ASR. </LI> <LI> The leaching rate of metals increased with increasing temperature and L/S ratio. </LI> <LI> The second-order kinetic model was best fitted (R<SUP>2</SUP> ≥ 0.99) with the metal leaching. </LI> <LI> The leaching rates of metals were controlled by both diffusion and chemical processes. </LI> <LI> Application of the advanced Fenton process greatly increased the recovery of metals. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Short-term Effects of Low Heavy Metal Contamination on Soil Nematode Community Structure

Byeong-yong Park,Jae-Kook Lee,Young Ho Kim 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.04

Influences of low concentration of heavy metals (As, Cd, Cu and Pb) on the nematode community structure were examined to assess the changes of the soil ecosystem for a short period of time. Notable increases of heavy metal concentration on the experiment soil were found on the maximum and their 4-1x concentration treatment of all heavy metals after 18weeks. Overall abundance of the nematodes increased regardless of kinds of heavy metal and their concentrations. Also there were no significant differences in the nematode abundance among all treatments of heavy metals except the abundance of c-p 4 in the maximum treatment of Pb. The number of nematode genus found in soils treated with heavy metal solutions also increased compared to that of the genus of the initial soils; however, no significant differences in richness were observed among the treatments of all heavy metals. In maturity and diversity indices of the nematode community, no significant changes occurred in the soils treated with heavy metal solutions with a few exceptions such as MI2-5 and ΣMI2-5 for Pb, and MI2-5 for As. Significant decreases of the ecological indices in the treatments with highly concentrated heavy metal solutions were noticed in MI2-5 and ΣMI2-5 for Pb, and MI2-5 for As, respectively. All of these results is supposed that the maturity and diversity of the nematode community may be decreased in soils contaminated with heavy metals such as Pb and As at relatively low concentrations of a short period of time, which may be derived from differential effects of heavy metals at low concentrations on the growth and development of the nematodes with different c-p values and trophic types. In the analysis of food web structure, only structure index (SI) was significantly lowered in soils irrigated with the heavy metal solutions of Pb and As, but enrichment index (EI) and channel index (CI) were not, suggesting that stressful soil conditions might be provided to the soil food web structure governed by direct toxic effects of heavy metals differential to nematode populations with different trophic type sandc-p values. Analyses of correlation coefficients also suggest that the influence of heavy metals at low concentrations, especially by Pb, maybe most prominent on the nematodes of c-p2-5, including fungivores, providing stressful soil environments.

Evaluation of heavy metals in hazardous automobile shredder residue thermal residue and immobilization with novel nano-size calcium dispersed reagent

Lee, Chi-Hyeon,Truc, Nguyen Thi Thanh,Lee, Byeong-Kyu,Mitoma, Yoshiharu,Mallampati, Srinivasa Reddy Elsevier 2015 Journal of hazardous materials Vol.296 No.-

<P><B>Abstract</B></P> <P>This study was conducted to synthesize and apply a nano-size calcium dispersed reagent as an immobilization material for heavy metal-contaminated automobile shredder residues (ASR) dust/thermal residues in dry condition. Simple mixing with a nanometallic Ca/CaO/PO<SUB>4</SUB> dispersion mixture immobilized 95–100% of heavy metals in ASR dust/thermal residues (including bottom ash, cavity ash, boiler and bag filter ash). The quantity of heavy metals leached from thermal residues after treatment by nanometallic Ca/CaO/PO<SUB>4</SUB> was lower than the Korean standard regulatory limit for hazardous waste landfills. The morphology and elemental composition of the nanometallic Ca/CaO-treated ASR residue were characterized by field emission scanning election microscopy combined with electron dispersive spectroscopy (FE-SEM/EDS). The results indicated that the amounts of heavy metals detectable on the ASR thermal residue surface decreased and the Ca/PO<SUB>4</SUB> mass percent increased. X-ray diffraction (XRD) pattern analysis indicated that the main fraction of enclosed/bound materials on ASR residue included Ca/PO<SUB>4</SUB>− associated crystalline complexes, and that immobile Ca/PO<SUB>4</SUB> salts remarkably inhibited the desorption of heavy metals from ASR residues. These results support the potential use of nanometallic Ca/CaO/PO<SUB>4</SUB> as a simple, suitable and highly efficient material for the gentle immobilization of heavy metals in hazardous ASR thermal residue in dry condition.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanometallic Ca/CaO/PO<SUB>4</SUB> for heavy metals immobilization in ASR residue. </LI> <LI> Heavy metals immobilization in dry condition attained about 95–100%. </LI> <LI> Remaining heavy metals were lower than the Korean standard regulatory limit. </LI> <LI> The amounts of heavy metals detectable on the ASR dust surface decreased. </LI> <LI> Nanometallic Ca/CaO/PO<SUB>4</SUB> has a promising potential for heavy metal remediation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Schematic representation of possible mechanisms determining the heavy metals immobilization efficiencyof ASR dust/thermal residues after treatment with nanometallic Ca/CaO/PO<SUB>4</SUB>.</P> <P>[DISPLAY OMISSION]</P>

Alcaligenes sp.의 생장과 인 제거에 미치는 이종 중금속 혼합의 독성 효과

김덕현 ( Deok Hyun Kim ),유진 ( Jin Yoo ),정근욱 ( Keun Yook Chung ) 한국환경농학회 2016 한국환경농학회지 Vol.35 No.1

BACKGROUND: This study was initiated to quantitatively evaluate the effects of five heavy metals on the growth and P removal efficiencies of Alcaligenes sp., known as the Phosphorus Accumulating Organisms (PAOs). It was cultivated in the batch system with five heavy metals, such as Cd, Cu, Zn, Pb and Ni, added in single and binary mixtures, respectively. METHODS AND RESULTS: IC50 (half of inhibition concentration of bacterial growth) and EC50 (half of effective concentration of phosphorus removal Efficiencies) were used to quantitatively evaluate the effects of heavy metals on the growth and phosphorus removal Efficiencies of Alcaligenes sp. In addition, Additive Index Value (A.I.V.) method was used to evaluate the interactive effects between Alcaligenes sp. and heavy metals. As a result, as the five heavy metals were singly added to Alcaligenes sp., the greatest inhibitory effects on the growth and P removal efficiencies of each bacteria was observed in the cadmium (Cd). In the binary mixture treatments of heavy metals, the treatments of lowest IC50 and EC50 were the Cd + Cu treatment. Based on the IC50 and EC50 of the binary mixtures of heavy metals treatments, most interactive effects between the heavy metals were found to be antagonistic. CONCLUSION: Based on the results obtained from this study, it appears that they could provide the basic information about the toxic effects of the respective treatments of single and binary mixtures of heavy metals on the growth and P removal efficiencies of Alcaligenes sp. through further study about the characterization of functional proteins involved in toxic effects of heavy metals.

Recent insights into autophagy and metals/nanoparticles exposure

Li Qiong,Feng Yajing,Wang Ruike,Liu Rundong,Ba Yue,Huang Hui 한국독성학회 2023 Toxicological Research Vol.39 No.3

Some anthropogenic pollutants, such as heavy metals and nanoparticles (NPs), are widely distributed and a major threat to environmental safety and public health. In particular, lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), and mercury (Hg) have systemic toxicity even at extremely low concentrations, so they are listed as priority metals in relation to their significant public health burden. Aluminum (Al) is also toxic to multiple organs and is linked to Alzheimer’s disease. As the utilization of many metal nanoparticles (MNPs) gradually gain traction in industrial and medical applications, they are increasingly being investigated to address potential toxicity by impairing certain biological barriers. The dominant toxic mechanism of these metals and MNPs is the induction of oxidative stress, which subsequently triggers lipid peroxidation, protein modification, and DNA damage. Notably, a growing body of research has revealed the linkage between dysregulated autophagy and some diseases, including neurodegenerative diseases and cancers. Among them, some metals or metal mixtures can act as environmental stimuli and disturb basal autophagic activity, which has an underlying adverse health effect. Some studies also revealed that specific autophagy inhibitors or activators could modify the abnormal autophagic flux attributed to continuous exposure to metals. In this review, we have gathered recent data about the contribution of the autophagy/mitophagy mediated toxic effects and focused on the involvement of some key regulatory factors of autophagic signaling during exposure to selected metals, metal mixtures, as well as MNPs in the real world. Besides this, we summarized the potential significance of interactions between autophagy and excessive reactive oxygen species (ROS)-mediated oxidative damage in the regulation of cell survival response to metals/NPs. A critical view is given on the application of autophagy activators/inhibitors to modulate the systematic toxicity of various metals/MNPs.

이축분종(異畜糞種) 퇴비에서의 중금속 화학종분화(化學種分化)

고한종,최홍림,김기연 한국동물자원과학회 2004 한국축산학회지 Vol.46 No.2

Composting animal manure is one of feasible treatments that reserves some portion of nutrients of manure. Although the application of compost to arable land has many advantages, the repeated cultivation of the agriculture land will accumulate the level of heavy metals in the soil which is potentially harmful to people and animals. Therefore it is important to know the characteristics concentration and species of heavy metals in a variety of chemical forms than just total content of the metal. Because the metals in different forms have different mobilities and bioavailabilites. The aim of this study was to examine the total content and the chemical forms of the heavy metals; Cr, Ni, Cu, Zn, As, Cd and Pb in the animal manure composed with sawdust or rice hull as a bulking agent. A total of 75 compost samples were collected throughout the country and classified into the three groups in accordance with the characteristics of raw materials; swine manure, poultry manure, and mixed(swine+poultry+cattle)manure. The compost samples were analyzed for total metal content and fractionated by sequential chemical extractions to estimate the quantities of metals: exchangeable, adsorbed, organically bound, carbonate and residual. The results showed that the heavy metal concentrations in all compost samples were lower than the maximum acceptable limits by the Korea Compost Quality Standards. The concentrations of heavy metals in the swine manure compost were higher than those of both the poultry and the mixed manure compost except for Cr, Zn and Cu concentrations of three different compost ranged from 157 to 839 ㎎ Zn/㎏ DM(dry matter) and from 47 to 457㎎ Cu/㎏ DM, depending on the composition of animal manures. The predominant forms for extracted metals were Cr, Ni, Zn, As and Pb, residual; Cu, organic; and Cd, carbonate. The results suggested that the legal standards for composts should be reexamined to revise the criteria on the total metal content as well as metal speciation.

Co-occurrence of heavy metals and antibiotics resistance in bacteria isolated from metal-polluted soil

Oluwarotimi John Joseph,Gbemisola Elizabeth Ogunleye,Kubrat Abiola Oyinlola,Augustina I. Balogun,Damilola Tolulope Olumeko 환경독성보건학회 2023 환경독성보건학회지 Vol.38 No.4

The indiscriminate deposition of metal-containing substances into the environment contributes significantly to high concentrations of metals in the soil resulting in resistance to metals and consequentially to antibiotics by inherent microbes which may eventually spread to other pathogenic microbes thereby elevating disease burden due to antibiotic resistance. The study aimed at determining the co-occurrence of resistance of bacteria isolated from metal-contaminated soil to heavy metals and subsequently, antibiotics. Metal-tolerant bacteria were randomly isolated from top soils from a battery waste site using the pour plate method. Selected isolates were identified using biochemical tests, then, subjected to elevating supplemented concentrations of different metal salts at 100-500 μg/mL to determine the minimum inhibitory concentration. Isolates tolerant to minimum three metals up to 400 μg/mL were subjected to Sulfamethoxazole-trimethoprim (25 μg), Imipenem (10 μg), Amoxicillin (30 μg), Ciprofloxacin (10 μg) and Tigecycline (15 μg) and observations interpreted using the guiding principle of the Clinical and Laboratory Standards Institute. Metal concentrations in the soils exceeded permissible limits. In total, 16 isolates were selected and identified as Proteus sp. (1), Pseudomonas spp. (5), Enterobacter spp. (2), Klebsiella spp. (2), Escherichia spp. (3), Raoultella spp. (2) and Rahnella sp. (1). Thirteen (81.25 %) of all isolates showed multi-resistance to the metals and seven exhibited multidrug-resistance, with 4 (57.1 %) showing resistance to three different classes of antibiotics and 3 (42.9 %) showed resistance to four antibiotic classes. Heavy metal-tolerant bacteria isolated from this study possess co-selection potentials as they showed resistance to different metals and antibiotics classes which is a concern to public health.