scholarly journals Photocatalysis for Heavy Metal Treatment: A Review

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1729
Author(s):  
Xinyu Gao ◽  
Xiangchao Meng
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Environmental Remediation ◽  
New Technology ◽  
Comprehensive Review ◽  
Metal Treatment ◽  
Oxidation Technology ◽  
Low Efficiency ◽  
Future Work ◽  
By Products

Environmental and human health are threatened by anthropogenic heavy metal discharge into watersheds. Traditional processes have many limitations, such as low efficiency, high cost, and by-products. Photocatalysis, an emerging advanced catalytic oxidation technology, uses light energy as the only source of energy. It is a clean new technology that can be widely used in the treatment of organic pollutants in water. Given the excellent adaptability of photocatalysis in environmental remediation, it can be used for the treatment of heavy metals. In this comprehensive review, the existing reported works in relevant areas are summarized and discussed. Moreover, recommendations for future work are provided.

Heavy metal removal by biomass-derived carbon nanotubes as a greener environmental remediation: A comprehensive review

Chemosphere ◽  
2021 ◽  
pp. 131959
Author(s):  
Anh Tuan Hoang ◽  
Sandro Nižetić ◽  
Chin Kui Cheng ◽  
Rafael Luque ◽  
Sabu Thomas ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Heavy Metal ◽  
Environmental Remediation ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Comprehensive Review

Experimental Study on New Technology for Solidifying/Stabilizing Papermaking Sludge

2010 ◽  
Vol 156-157 ◽  
pp. 84-89
Author(s):  
Xu Nan Ning ◽  
Shi Wen Li ◽  
Jing Yong Liu ◽  
Zuo Yi Yang ◽  
Zhu Ying
Keyword(s):  
Mechanical Properties ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Compressive Strength ◽  
New Technology ◽  
Oxygen Demand ◽  
Heavy Metal Concentration ◽  
National Standards ◽  
Curing Time ◽  
Water Ratio

For better harmlessly treatment of papermaking sludge, a new technology for solidifying and stabling of sludge was studied. Papermaking sludge was solidified and stabilized by the solidifying agents including cement, powder fly ash (PFA) and cinder. The mechanical properties of solidified sludge block were evaluated by compressive strength, chemical oxygen demand (COD) and heavy metals concentration in the leachate from the solidified block were tested as well. When the solidifying agents has the following composition (cement 0.12kg/kg, PFA 0.02kg/kg and cinder 0.10kg/kg respectively), and the curing time was 6ds, the compressive strength of the solidified sludge blocks reached 360kPa. The results showed that cement and cinder were all positive in the compressed strength of sludge block. If they were mixed with PFA together, they could enhanced the solidification of organic and heavy metals in the sludge. Under this conditions, the COD in leachate from the solidified block was 115.7 mg/L, and the heavy metal concentration had reached the related national standards, after 6ds of curing time, water ratio of the solidified block kept from 35% to 40%, which met the prescribed standards of landfill.

scholarly journals Stress physiology of palm trees II. The effect of heavy metals and high irradiance on the photosynthesis of palm Trachycarpus fortunei

1999 ◽  
Vol 5 (1-2) ◽  
Author(s):  
A. Neményi ◽  
J. Kissimon ◽  
M. Droppa ◽  
M. Baron ◽  
G. Horváth
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Light Exposure ◽  
Fluorescence Induction ◽  
High Irradiance ◽  
Stress Factors ◽  
Palm Trees ◽  
Metal Treatment ◽  
Total Fluorescence ◽  
The Individual

A study was carried out to analyse the individual and combined effects of heavy metal toxicity and high irradiance on the photosynthetic characteristics of young, fully expanded leaves of palm seedling Trachycarpus fortunei under laboratory conditions. Heavy metals were found to inhibit both the light and dark reactions of photosynthesis and the inhibition was more affected in the light than in the dark. Single photoinhibitory conditions caused a 60 % decrease in the electron transport activity after 120 min of light exposure which was completely reversible in the dark. In contrast, the combined effect of high light and heavy metal treatment resulted in a 90 % decrease in the activity, but no reversible recovery in the dark could be detected. This indicated that the simultaneous effect of these two stress factors led to irreversible damages of the photosynthetic machinery and as a consequence caused the general destruction of the plant. Abbreviations and symbols: Fo: initial chlorophyll fluorescence; Fm: maximum total fluorescence; Fv: variable fluorescence; AFi: intermediate level of fluorescence induction; PSII: photosystem 2.  

scholarly journals Impact of heavy metal ions on the simultaneous saccharification and fermentation of formosan alder biomass to form lactic acid

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 882-892
Author(s):  
Chu-Han Ko ◽  
Ko-Yo Liu ◽  
Bing-Yuan Yang ◽  
Fang-Chih Chang ◽  
Po-Heng Lin
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Lactic Acid ◽  
Environmental Remediation ◽  
Simultaneous Saccharification And Fermentation ◽  
Lactic Acid Production ◽  
Heavy Metal Concentration ◽  
Wide Range ◽  
Negative Impacts ◽  
Simultaneous Saccharification

Formosan alder (Alnus formosana) is a fast-growing, adaptable, pioneer native tree species in Taiwan, and it is particularly suitable for reforestation. In this study, steam-exploded Formosan alder biomass was employed to investigate lactic acid production by simultaneous saccharification and fermentation (SSF) in the presence of different heavy metals. Impacts of added heavy metals on saccharification processing were investigated. In the presence of 1410 mg Cr6+/L, negative impacts were observed for SSF. The same level of Cr6+ adversely affected fermentation by Lactobacillus casei and L. acidophilus compared to the blank controls. Positive impacts for SSF by Cd2+ were demonstrated with 108 mg Cd2+/L, and the same conditions favored fermentation by L. casei and L. acidophilus. No impacts for SSF by Pb2+ up to 6830 mg Pb2+/L were found for both Lactobacillus strains. This study demonstrates that SSF for production of lactic acid from Formosan alder biomass was able to tolerate a wide range of heavy metal concentration regimes. Hence, this study provides an alternative use for biomass harvested from phytoremediation sites. Such biomass can be used as sustainable regenerative biomaterial, and thereby it can further enhance the benefits of environmental remediation.

Removal of Heavy Metal Contaminants from Wastewater by Using Chlorella vulgaris Beijerinck: A Review

2020 ◽  
Vol 6 (3) ◽  
pp. 174-187 ◽  
Author(s):  
Faezeh Manzoor ◽  
Abdolreza Karbassi ◽  
Abooali Golzary
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Chlorella Vulgaris ◽  
Wastewater Treatment Process ◽  
Time Period ◽  
Removal Of Heavy Metals ◽  
Zinc Cadmium ◽  
Metal Treatment ◽  
Lead Zinc ◽  
Main Factor

Removal of heavy metals is very important in wastewater treatment process, due to their abundant hazardous effects. There are various chemical and physical methods including ion exchange, reverse osmosis, electrodialysis, and ultrafiltration for removing heavy metals from wastewater, but biological treatment has attracted researchers for years as it is cheap and efficient. Microalgae have a significant capability of absorbing and eliminating heavy metals from wastewater. One of the most attractive microalgae species for this application is the Chlorella vulgaris Beijerinck. The current study takes a literature review of using microalgae species, especially C. vulgaris, with the aim of wastewater heavy metal treatment. In this regard firstly, various methods of eliminating heavy metals using microalgae were investigated, and then the application of C. vulgaris in the process of eliminating heavy metals from wastewater is fully presented. It became obvious that the use of C. vulgaris application is more helpful in the case of Copper, Lead, Zinc, Cadmium, and Nickel. Moreover, the main factor affecting heavy metal treatment using C. vulgaris is the pH of media, and the second effective parameter is temperature that is often considered about 25°C. The appropriate time period for the treatment was 5-7 days. Generally, C. vulgaris presented a very favorable efficiency in eliminating various heavy metals and is capable of removing heavy metals from wastewater to more than 90% on average.

scholarly journals The Growth and Antioxidative Responses of Sonchus oleraceus (Linnaeus, 1753) Under Cu(II), Pb(II), Cd(II) and Cr(VI) Stress Condition

2017 ◽  
Vol 3 (4) ◽  
pp. 157
Author(s):  
Nur Hidayaturrohmah ◽  
Sri Kasmiyati ◽  
Sucahyo . ◽  
Zane Vincēviča-Gaile
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Dry Weight ◽  
Sonchus Oleraceus ◽  
Antioxidative Responses ◽  
Randomized Design ◽  
Growing Medium ◽  
Metal Treatment ◽  
Completely Randomized Design ◽  
The Impact

<p class="Els-Abstract-text">Plants growing in soil containing heavy metal  polutan such as chromium (Cr), lead (Pb), cadmium (Cd) and copper (Cu)  will be stunted, and  increase production of Reactive Oxygen Species (ROS). In dealing with the excess amount of ROS, plants have an enzymatic defense system, using superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxide (APX). The aim of this study was to determine and analyze the <em>Sonchus oleraceus</em> (Linnaeus, 1753) plant response to heavy metals stress, seen from the growth and antioxidative defense enzymatically. Research carried out using a Completely Randomized Design (CRD) with four treatments and five replicates. The metal treatment was 10 mg · L<sup>–1</sup>. The presence of heavy metals in the growing medium significantly decreased the plant height and leaf area, so the impact is on the weight of wet and dry weight. The metal treatments of Cr, Cd, Pb and Cu increase the activity of SOD and APX enzymes but decrease the activity of the CAT enzyme. Chromium is a metal that has a significant influence on the growth and activity of SOD, APX, and CAT enzymes in <em>S. oleraceus</em>.</p><div><p class="Els-keywords"><strong>Keywords:</strong> antioxidative responses; growth; heavy metal; <em>Sonchus oleraceus; </em>toxicity.</p></div>

scholarly journals Synthesis and Water Treatment Applications of Nanofibers by Electrospinning

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1779
Author(s):  
Saumya Agrawal ◽  
Rashmi Ranjan ◽  
Bajrang Lal ◽  
Ashiqur Rahman ◽  
Swatantra P. Singh ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Water Treatment ◽  
Environmental Remediation ◽  
Electrode Materials ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Membrane Distillation ◽  
Electrospinning Process

In the past few decades, the role of nanotechnology has expanded into environmental remediation applications. In this regard, nanofibers have been reported for various applications in water treatment and air filtration. Nanofibers are fibers of polymeric origin with diameters in the nanometer to submicron range. Electrospinning has been the most widely used method to synthesize nanofibers with tunable properties such as high specific surface area, uniform pore size, and controlled hydrophobicity. These properties of nanofibers make them highly sought after as adsorbents, photocatalysts, electrode materials, and membranes. In this review article, a basic description of the electrospinning process is presented. Subsequently, the role of different operating parameters in the electrospinning process and precursor polymeric solution is reviewed with respect to their influence on nanofiber properties. Three key areas of nanofiber application for water treatment (desalination, heavy-metal removal, and contaminant of emerging concern (CEC) remediation) are explored. The latest research in these areas is critically reviewed. Nanofibers have shown promising results in the case of membrane distillation, reverse osmosis, and forward osmosis applications. For heavy-metal removal, nanofibers have been able to remove trace heavy metals due to the convenient incorporation of specific functional groups that show a high affinity for the target heavy metals. In the case of CECs, nanofibers have been utilized not only as adsorbents but also as materials to localize and immobilize the trace contaminants, making further degradation by photocatalytic and electrochemical processes more efficient. The key issues with nanofiber application in water treatment include the lack of studies that explore the role of the background water matrix in impacting the contaminant removal performance, regeneration, and recyclability of nanofibers. Furthermore, the end-of-life disposal of nanofibers needs to be explored. The availability of more such studies will facilitate the adoption of nanofibers for water treatment applications.

scholarly journals Effects of Wood Vinegar and Bio char on Germination of Pakchoi Seeds under Different Cadmium Stress Conditions

2021 ◽  
pp. 267-281
Author(s):  
YongChol Ju ◽  
Xu Zhang ◽  
Chol Jong ◽  
TaeHo Yun ◽  
IINam Ri ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Cadmium Stress ◽  
Heavy Metal Stress ◽  
Fresh Weight ◽  
Wood Vinegar ◽  
Combined Application ◽  
Mixed Treatment ◽  
Metal Treatment ◽  
Cadmium Contaminated Soil

Wood vinegar is widely used as a strong antioxidant, bacteria prevention, plant growth agent, an insecticide, and its effectiveness is shown in heavy metal treatment at this time.Wood vinegar liquid contains organic acids and phenols, which are effective in adsorbing heavy metals. Although a lot of studies have been conducted on the adsorption of heavy metals from biochar, the effect of mixing biochar and wood vinegar liquid on plant budding, and soil heavy metal morphology changes few studies have been analyzed. This paper analyzes the effects of Wood vinegar and biochar on the sprouting of pakchoi grown in different threats of cadmium from the nature of Wood vinegar. As a result, it was confirmed that the optimum concentration of the applied fertilizer wood vinegar that lowers the plant effectiveness of Cadmium was 1.0%. The fresh weight of pakchoi changed significantly in the order of biochar + wood vinegar 1.0% mixing> biochar> control. When 5.0% Biochar was mixed with 1.0% wood vinegar, the immobilization effect of the residual state and the carbonate bound cadmium in the soil was the highest. The combined application of wood vinegar and biochar promotes the germination of pakchoi, and has a significant inactivation effect on cadmium-contaminated soil; the results of analyzing the effectiveness of the mixing of wood vinegar and biochar and separate fertilization for each soil index show that, Compared to before sowing the pH ratio of the mixed treatment of biochar + wood vinegar is higher than that of the single treatment zone, which is as high as between 6.6-6.8, the EC is reduced to 2-59mS/cm width, and the CEC is increased by 0.27-2.21 times. It shows that under heavy metal stress, the mixed treatment of biochar+wood vinegar solution 1.0% is more effective than the treatment of biochar alone and the control.

scholarly journals Heavy metal pollution and the role of inorganic nanomaterials in environmental remediation

2021 ◽  
Vol 8 (10) ◽  
Author(s):  
Michael B. Mensah ◽  
David J. Lewis ◽  
Nathaniel O. Boadi ◽  
Johannes A. M. Awudza
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Environmental Remediation ◽  
Synthesis Method ◽  
Inorganic Nanoparticles ◽  
Critical Parameters ◽  
Toxic Heavy Metals ◽  
Metals Removal ◽  
Removal Of Heavy Metals ◽  
Inorganic Nanomaterials

Contamination of water and soil with toxic heavy metals is a major threat to human health. Although extensive work has been performed on reporting heavy metal pollutions globally, there are limited review articles on addressing this pernicious phenomenon. This paper reviews inorganic nanoparticles and provides a framework for their qualities required as good nanoadsorbents for efficient removal of heavy metals from water. Different inorganic nanoparticles including metals, metal oxides and metal sulfides nanoparticles have been applied as nanoadsorbents to successfully treat water with high contaminations of heavy metals at concentrations greater than 100 mg l −1 , achieving high adsorption capacities up to 3449 mg g −1 . It has been identified that the synthesis method, selectivity, stability, regeneration and reusability, and adsorbent separation from solution are critical parameters in deciding on the quality of inorganic nanoadsorbents. Surface functionalized nanoadsorbents were found to possess high selectivity and capacity for heavy metals removal from water even at a very low adsorbent dosage of less than 2 g l −1 , which makes them better than conventional adsorbents in environmental remediation.

Heavy metal removal from wastewater using zero-valent iron nanoparticles

2008 ◽  
Vol 58 (10) ◽  
pp. 1947-1954 ◽  
Author(s):  
S. Y. Chen ◽  
W. H. Chen ◽  
C. J. Shih
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Removal Efficiency ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Zero Valent Iron ◽  
Affecting Factors ◽  
High Concentration ◽  
Initial Ph ◽  
Low Efficiency

Because of having a high reduction potential, the zero-valent iron (ZVI) is often applied for the remediation of wastewater or groundwater with heavy metals. The purpose of this study was aimed to investigate the reaction behavior of heavy metals with ZVI nanoparticles in the wastewater. The affecting factors, such as initial pH, dosage of nanoscale ZVI and initial concentration of heavy metal, on the removal efficiency of heavy metals by ZVI in the wastewater were examined by the batch experiments in this study. It was found that the removal of heavy metals was affected by initial pH. The rate and efficiency of metal removal increased with decreasing initial pH. Greater than 90% of the heavy metals were removed when the initial pH was controlled at 2. In addition, the rate and efficiency of metal removal increased as the dosage of nanoscale ZVI increased. The removal efficiency of heavy metal was higher than 80% when 2.0 g/L of ZVI was added in the wastewater. On the other hand, the slow rate and low efficiency of metal removal from the wastewater treated by nanoscale ZVI was found in the wastewater with high concentration of heavy metal.

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