Role of Nano-Photocatalysts for Detoxification of Toxic Heavy Metal

2019 ◽  
Vol 16 ◽  
Author(s):  
M. Bilal Tahir ◽  
Abdullah M. Asiri ◽  
M. Faheem Malik ◽  
N. R. Khalid ◽  
T. Iqbal ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Recent Literature ◽  
Environmental Issues ◽  
Aqueous Environment ◽  
Toxic Heavy Metals ◽  
Toxic Heavy Metal ◽  
Heavy Metal Detoxification ◽  
Green Technique

Background: Nano-photocatalysis through semiconductor-based materials has become an emerging and eye-catching approach for detoxification of hazardous heavy metals in the aqueous environment. Method: In this article, photocatalysis being a green technique along with several other detoxification technologies for toxic heavy metals have been reviewed. Toxic Effects: Further, the adverse effects of heavy metals on human health, agriculture lands, environment, and aquatic system were investigated. Toxic heavy-metals contribute to numerous environmental issues based on their toxicity. Result: Various types of photocatalysts were revised in recent literature for the detoxification of heavy metals. The recycling of photocatalysts may be anticipated as a worthy method for wastewater treatment has also been discussed with recent examples. Conclusion: Moreover, it concludes with efficiency, challenges and new future perspectives for heavy metal detoxification using photocatalysis.

ASSESSMENT OF HEAVY METAL CONCENTRATION IN COCONUT WATER

1970 ◽  
pp. 07-10
Author(s):  
MdDidarul Islam, Ashiqur Rahaman, Aboni Afrose
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Concentration ◽  
Coconut Water ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Toxic Heavy Metal ◽  
Low Concentration ◽  
Wet Ashing ◽  
Aas Method

This study was based on determining concentration of essential and toxic heavy metal in coconut water available at a local Hazaribagh area in Dhaka, Bangladesh. All essential minerals, if present in the drinking water at high concentration or very low concentration, it has negative actions. In this study, fifteen samples and eight heavy metals were analyzed by Atomic Absorption Spectroscopy (AAS) method which was followed by wet ashing digestion method. The concentration obtained in mg/l were in the range of 0.3 to 1.5, 7.77 to 21.2, 0 to 0.71, 0 to 0.9, 0 to 0.2, 0.9 to 17.3, 0.1 to 0.9, 0 to 0.9 and 0 to 0.7 for Fe, Ni, Cu, Cd, Cr, Zn, Pb and Se respectively. From this data it was concluded that any toxic heavy metals like Cd, Cr, Pb and Ni exceed their toxicity level and some essential nutrients were in low concentration in those samples. 

scholarly journals Bioremediation of Chromium by Microorganisms and Its Mechanisms Related to Functional Groups

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Abate Ayele ◽  
Yakob Godebo Godeto
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Functional Groups ◽  
Heavy Metal Ions ◽  
Future Research ◽  
Oil Well ◽  
Toxic Heavy Metals ◽  
Toxic Heavy Metal ◽  
Minimum Concentration

Heavy metals generated mainly through many anthropogenic processes, and some natural processes have been a great environmental challenge and continued to be the concern of many researchers and environmental scientists. This is mainly due to their highest toxicity even at a minimum concentration as they are nonbiodegradable and can persist in the aquatic and terrestrial environments for long periods. Chromium ions, especially hexavalent ions (Cr(VI)) generated through the different industrial process such as tanneries, metallurgical, petroleum, refractory, oil well drilling, electroplating, mining, textile, pulp and paper industries, are among toxic heavy metal ions, which pose toxic effects to human, plants, microorganisms, and aquatic lives. This review work is aimed at biosorption of hexavalent chromium (Cr(VI)) through microbial biomass, mainly bacteria, fungi, and microalgae, factors influencing the biosorption of chromium by microorganisms and the mechanism involved in the remediation process and the functional groups participated in the uptake of toxic Cr(VI) from contaminated environments by biosorbents. The biosorption process is relatively more advantageous over conventional remediation technique as it is rapid, economical, requires minimal preparatory steps, efficient, needs no toxic chemicals, and allows regeneration of biosorbent at the end of the process. Also, the presence of multiple functional groups in microbial cell surfaces and more active binding sites allow easy uptake and binding of a greater number of toxic heavy metal ions from polluted samples. This could be useful in creating new insights into the development and advancement of future technologies for future research on the bioremediation of toxic heavy metals at the industrial scale.

scholarly journals Pengaruh CdCl2 terhadap Produksi Eksopolisakarida dan Daya Hidup Azotobacter

2012 ◽  
Vol 12 (1) ◽  
pp. 34 ◽  
Author(s):  
Reginawanti Hindersah ◽  
Dedeh Hudaya Arief ◽  
Soetijoso Soemitro ◽  
Lukman Gunarto
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Liquid Medium ◽  
Human Health ◽  
Contaminated Soil ◽  
Room Temperature ◽  
Gravimetric Method ◽  
Soil Bioremediation ◽  
Toxic Heavy Metals ◽  
Toxic Heavy Metal

The contamination of toxic heavy metal Cadmium (Cd) in soils will be endanger the human health because it ismore available comparing to another toxic heavy metals. One method of Cd-contaminated soil bioremediation isusing exopolysachharide-producing bacteria Azotobacter. Exopolysachharides (EPS) can mobilize Cd through theformation of complex Cd-EPS which sequentially can increase the availability of Cd for plants uptake. A laboratoryexperiment has been done to study the EPS production and the viability of six Azotobacter isolates in the liquidculture containing 0.01, 0.1, and 1 mM CdCl2. The bacteria were cultured in liquid medium with and without CdCl2 for72 hours at room temperature. The EPS production was determined by gravimetric method after precipitationusing acetone and centrifugation at 7000 rpm. The result was that all of Azotobacter isolates produce EPS in thepresence of CdCl2. In the culture with 1 mM CdCl2, the density of Azotobacter sp. isolate BS3, LK5, LKM6 increasedsignificantly, and that of isolate LH16 decreased. No significant effect of CdCl2 on the density of isolate BS2 andLH15. This research suggested that some Azotobacter isolates were relatively resistence to the Cd and could bedeveloped as biological agents in Cd-contaminated soil bioremediation.

Facile fabrication of silk protein sericin-mediated hierarchical hydroxyapatite-based bio-hybrid architectures: excellent adsorption of toxic heavy metals and hazardous dye from wastewater

RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 86607-86616 ◽  
Author(s):  
Pradyot Koley ◽  
Makoto Sakurai ◽  
Toshiaki Takei ◽  
Masakazu Aono
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Congo Red ◽  
Heavy Metal Ions ◽  
Silk Protein ◽  
Toxic Heavy Metals ◽  
Toxic Heavy Metal ◽  
Hybrid Architectures ◽  
Facile Fabrication

Facilely fabricated silk protein sericin-mediated hierarchical hydroxyapatite hybrid architectures show excellent adsorption of toxic heavy metal ions of Pb(ii), Cd(ii) and Hg(ii) and a hazardous dye, Congo red (CR), from wastewater.

Induction of metallothionein-I mRNA in cultured cells by heavy metals and iodoacetate: evidence for gratuitous inducers

1984 ◽  
Vol 4 (3) ◽  
pp. 484-491
Author(s):  
D M Durnam ◽  
R D Palmiter
Keyword(s):  
Heavy Metals ◽  
Cultured Cells ◽  
Mrna Accumulation ◽  
Mouse Hepatocyte ◽  
Hepatocyte Cell Line ◽  
Regulatory Molecule ◽  
Heavy Metal Detoxification ◽  
Double Minute ◽  
Double Minute Chromosomes

A mouse hepatocyte cell line selected for growth in 80 microM CdSO4 (Cdr80 cells) was used to test the role of metallothioneins in heavy metal detoxification. The cadmium-resistant (Cdr80) cells have double minute chromosomes carrying amplified copies of the metallothionein-I gene and accumulate ca. 20-fold more metallothionein-I mRNA than unselected cadmium-sensitive (Cds) cells after optimal Cd stimulation. As a consequence, the amount of Cd which inhibits DNA synthesis by 50% is ca. 7.5-fold higher in Cdr80 cells than in Cds cells. Cds and Cdr80 cells were compared in terms of their resistance to other heavy metals. The results indicate that although Zn, Cu, Hg, Ag, Co, Ni, and Bi induce metallothionein-I mRNA accumulation in both Cdr80 and Cds cells, the Cdr80 cells show increased resistance to only a subset of these metals (Zn, Cu, Hg, and Bi). This suggests that not all metals which induce metallothionein mRNA are detoxified by metallothionein and argues against autoregulation of metallothionein genes. Metallothionein-I mRNA is also induced by iodoacetate, suggesting that the regulatory molecule has sensitive sulfhydryl groups.

scholarly journals Heavy metal composition of maize and tomato grown on contaminated soils

2018 ◽  
Vol 3 (1) ◽  
pp. 414-426
Author(s):  
A.O. Adekiya ◽  
A.P. Oloruntoba ◽  
S.O. Ojeniyi ◽  
B.S. Ewulo
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Contaminated Soils ◽  
Heavy Metal Contamination ◽  
Mining Area ◽  
Atomic Absorption Spectrophotometry ◽  
Toxic Heavy Metals ◽  
Mining Site ◽  
Solanum Lycopersicum L ◽  
Sources Of Pollution

Abstract The study investigated the level of heavy metal contamination in plants {maize (Zea mays) and tomato (Solanum lycopersicum L.)} from thirty soil samples of three locations (Epe, Igun and Ijana) in the Ilesha gold mining area, Osun State, Nigeria. Total concentrations of As, Cd, Co, Cr, Cu, Ni, Pb and Zn were determined using atomic absorption spectrophotometry. Spatial variations were observed for all metals across the locations which was adduced to pH and the clay contents of the soils of each location. The results showed that heavy metals are more concentrated in the areas that are closer to the mining site and the concentrations in soil and plants (maize and tomato) decreased with increasing perpendicular distance from the mining site, indicating that the gold mine was the main sources of pollution. The mean concentrations of heavy metals in plants (tomato and maize) samples were considered to be contaminated as As, Cd and Pb respectively ranged from 0.6 - 2.04 mg kg-1, 0.8 - 5.2 mg kg-1, 0.8 - 3.04 mg kg-1 for tomato and respectively 0.60 - 2.00 mg kg-1, 1.50 - 4.60 mg kg-1 and 0.90 - 2.50 mg kg-1 for maize. These levels exceeded the maximum permissible limits set by FAO/WHO for vegetables. In conclusion, monitoring of crops for toxic heavy metals is essential for food safety in Nigeria.

scholarly journals Metalliferous content of drinking water and sediments in storage tanks of some schools in Erbil city, Iraq

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Hawraz Sami Khalid ◽  
Hoshyar Saadi Ali ◽  
Dhary Almashhadany
Keyword(s):  
Heavy Metals ◽  
Water Quality ◽  
Heavy Metal ◽  
Drinking Water ◽  
Water Samples ◽  
World Health ◽  
Storage Tanks ◽  
Quality Indices ◽  
Toxic Heavy Metals ◽  
Water Quality Indices

The present study was conducted to evaluate the quality of drinking water in randomly selected schools in Erbil city, Kurdistan Region, Iraq. The water quality indices such as the Heavy metal Pollution Index (HPI) and Heavy metal Evaluation Index (HEI) were applied to characterize water quality. Eighteen schools were incorporated and sampled for their water storage tanks available to students. Water samples and sediment samples from tanks floor were analyzed by Inductively Coupled Plasma Optical Emission Spectrometer for the determination of twenty-two metal elements. In drinking water samples, all detected metals did not exceed the permissible limits of the World Health Organization. The results of this study showed that the average values of HPI and HEI for As, Cd, Cr, Cu, Fe, Pb, Mn, Ni, and Zn were 54.442 and 0.221, respectively. According to data of the water quality indices, the schools drinking water quality are good and suitable for drinking in terms of heavy metals. However, sediments samples contained high concentrations of all elements including the toxic heavy metals (As, Cd, Cr, and Pb). Re-suspension of sediments into water column after refilling storage tanks can pose a serious threat to students drinking water from such vessels. It is therefore recommended that proper storage tanks are provided to the schools accompanied by continuous sanitation and hygiene practice to mitigate the corrosion of tanks to avoid health risks of toxic metal

scholarly journals Spatial distribution of heavy metals in surface sediments of Kalametiya Lagoon in southern Sri Lanka; insight towards pollution status and socio-economic interactions

2021 ◽  
Author(s):  
Sunanda Kodikara ◽  
Hossein Tiemoory ◽  
Mangala Chathura De Silva ◽  
Pathmasiri Ranasinghe ◽  
Sudarshana Somasiri ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Spatial Distribution ◽  
Sri Lanka ◽  
Suspended Sediments ◽  
Potential Effect ◽  
Toxic Heavy Metals ◽  
Threshold Effect Level ◽  
Effect Level ◽  
Economic Interactions

Abstract Heavy metal (HM) pollution has become a serious threat to coastal aquatic ecosystems. This study, therefore, aimed at assessing the spatial distribution of selected heavy metals/metalloids including Arsenic (As), Cadmium (Cd), Chromium (Cr), Lead (Pb), and Mercury (Hg) in surface sediment (0–15 cm) samples collected across Kalametiya Lagoon in southern Sri Lanka. Forty-one (41) grid points of the lagoon were sampled and the sediment samples were analyzed for HM content by using ICP-MS. A questionnaire survey was carried out to investigate the possible sources for HM pollution in Kalametiya Lagoon. Water pH and salinity showed significant variation across the lagoon. Overall mean value of pH and salinity were 6.68 ± 0.17 and 2.9 ± 2.2 PSU respectively. The spatial distribution of the heavy metals was not monotonic and showed a highly spatial variation. The kernel density maps of the measured heavy metals demarcated several different areas of the lagoon. The mean contents of As, Cd, Cr, Hg, and Pb were lower than that of threshold effect level (TEL) however, higher for Hg at the North Inlet. Nevertheless, it was still lower than potential effect level (PEL). Socio-economic interactions have dramatically reduced during the past two decades. Industrial sewage, river suspended sediments and agrochemicals such as fertilizers, pesticides were reportedly identified as the possible sources for heavy metal loads. Accumulation of toxic heavy metals can be minimized by detouring the water inflow to the lagoon.

scholarly journals Heavy Metals Removal from Water by Efficient Adsorbents

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2659
Author(s):  
Muhammad Zaim Anaqi Zaimee ◽  
Mohd Sani Sarjadi ◽  
Md Lutfor Rahman
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Water Treatment ◽  
Adsorption Process ◽  
Natural Occurrence ◽  
Toxic Heavy Metals ◽  
Major Purpose ◽  
Treatment Methods ◽  
Metals Removal ◽  
Harmful Effects

Natural occurrence and anthropogenic practices contribute to the release of pollutants, specifically heavy metals, in water over the years. Therefore, this leads to a demand of proper water treatment to minimize the harmful effects of the toxic heavy metals in water, so that a supply of clean water can be distributed into the environment or household. This review highlights several water treatment methods that can be used in removing heavy metal from water. Among various treatment methods, the adsorption process is considered as one of the highly effective treatments of heavy metals and the functionalization of adsorbents can fully enhance the adsorption process. Therefore, four classes of adsorbent sources are highlighted: polymeric, natural mineral, industrial by-product, and carbon nanomaterial adsorbent. The major purpose of this review is to gather up-to-date information on research and development on various adsorbents in the treatment of heavy metal from water by emphasizing the adsorption capability, effect of pH, isotherm and kinetic model, removal efficiency and the contact of time of every adsorbent.

scholarly journals Role of nitric oxide in plant responses to heavy metal stress: exogenous application versus endogenous production

2019 ◽  
Vol 70 (17) ◽  
pp. 4477-4488 ◽  
Author(s):  
Laura C Terrón-Camero ◽  
M Ángeles Peláez-Vico ◽  
Coral Del-Val ◽  
Luisa M Sandalio ◽  
María C Romero-Puertas
Keyword(s):  
Nitric Oxide ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Human Health Risk ◽  
Heavy Metal Stress ◽  
Metal Stress ◽  
Future Research ◽  
Plant Responses ◽  
Research Perspectives

Abstract Anthropogenic activities, such as industrial processes, mining, and agriculture, lead to an increase in heavy metal concentrations in soil, water, and air. Given their stability in the environment, heavy metals are difficult to eliminate and can constitute a human health risk by entering the food chain through uptake by crop plants. An excess of heavy metals is toxic for plants, which have various mechanisms to prevent their accumulation. However, once metals enter the plant, oxidative damage sometimes occurs, which can lead to plant death. Initial production of nitric oxide (NO), which may play a role in plant perception, signalling, and stress acclimation, has been shown to protect against heavy metals. Very little is known about NO-dependent mechanisms downstream from signalling pathways in plant responses to heavy metal stress. In this review, using bioinformatic techniques, we analyse studies of the involvement of NO in plant responses to heavy metal stress, its possible role as a cytoprotective molecule, and its relationship with reactive oxygen species. Some conclusions are drawn and future research perspectives are outlined to further elucidate the signalling mechanisms underlying the role of NO in plant responses to heavy metal stress.

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