scholarly journals Remediation of Heavy Metals from Soil by Eco Approaches

2019 ◽  
Vol 5 ◽  
pp. 1
Author(s):  
Manish Batham ◽  
Jot Sharma ◽  
◽  

The contamination of soil by anthropogenic activities is of great concern in recent times. There is an urgent demand of reliable and eco-friendly approaches for remediation of this concern. The current techniques for heavy metal remediation from contaminated soil are costly, time consuming, and harmful for the environment. Toxicity of heavy metals can reduce plant growth, and a high level of presence of these heavy metals is a risk factor to human and plant health. Heavy metals neither biodegradable materials nor are created. They occur naturally in the earth crust, and they reach the environment by human activities. Organic compounds can be degraded, but metals cannot degrade, and therefore effective cleanup requires its immobilization to reduce or remove toxicity. Recently, research focuses on cost-effective technologies to clean polluted areas. Vermiremediation and phytoremediation are two such useful techniques. In these eco-friendly techniques of remediation, the target plants accumulate, volatilize the contaminants, or convert them into some nontoxic forms, thus remediating the soil.

Author(s):  
Piyush Gupta ◽  
Garima Nagpal ◽  
Namrata Gupta

Abstract Background The water supplies are hindered because aquatic resources have constrained with natural and man-made pollution activities in terms of releasing huge amounts of contaminants from different point and non-point sources across the globe. The industries like metal plating, batteries, paint, fertilizers, tanneries, textile industries, dyeing industries, mining operations, and paper industries discharge their effluents into the environment directly or indirectly, and hence, they are considered as the key sources of heavy metals contamination in water resources. Heavy metals are inorganic, non-biodegradable, persistent, and having a tendency to get accumulated in biotic and abiotic components of environment as compared to organic pollutants. Some heavy metal cations, for example, mercury, arsenic, cadmium, zinc, lead, nickel, copper, and chromium, are carcinogenic in nature and so, lethal. There are growing health concerns due to toxic impacts of heavy metals on every genre of ecosystem. To deal with the bottleneck situation, it is highly imperative to search a feasible solution for heavy metal remediation in water in context of preventing amalgamation of noxious contaminants in food web. Different methods are exercised for the remediation of such impurities from its solutions. One method, i.e. adsorption is found to be the simplest, economical, efficient, and eco-friendly in this context. Main body Geopolymers exhibit heterogeneous amorphous microstructure and wide surface area. The compatibility for depollution and the performance of these materials mainly depend upon their preparation methods, composition, and microstructure. Fly ash-based geopolymer may serve as a better alternate to various cost-effective adsorbents and it will be a proven environmentally viable, waste to money solution by consuming heaps of fly ash waste for the adsorbent modified by using fly ash. The possible utilization of wastes from several industries is a matter of concerned sustainability benefits. This study shows that fly ash-based geopolymers have the potential to cope up with the problems and risk factors associated with the fly ash waste management and it would be the utmost scientific panacea in the field of removing toxins from aqueous medium and maintain environmental health in the future. Short conclusions The literature available in different databases is very limited pertaining to heavy metal remediation using fly ash-based geopolymers. Keeping all the factors in mind, this article is an attempt to summarize relevant informations related to work done on fly ash-based geopolymers for treating aqueous solutions comprising heavy metals.


2012 ◽  
Vol 19 (4) ◽  
pp. 533-547
Author(s):  
Juris Burlakovs ◽  
Magnuss Vircavs

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.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1461
Author(s):  
Roberto Braglia ◽  
Lorenza Rugnini ◽  
Sara Malizia ◽  
Francesco Scuderi ◽  
Enrico Luigi Redi ◽  
...  

Increasing levels of freshwater contaminants, mainly due to anthropogenic activities, have resulted in a great deal of interest in finding new eco-friendly, cost-effective and efficient methods for remediating polluted waters. The aim of this work was to assess the feasibility of using a green microalga Desmodesmus sp., a cyanobacterium Nostoc sp. and a hemicryptophyte Ampelodesmos mauritanicus to bioremediate a water polluted with an excess of nutrients (nitrogen and phosphorus) and heavy metals (copper and nickel). We immediately determined that Nostoc sp. was sensitive to metal toxicity, and thus Desmodesmus sp. was chosen for sequential tests with A. mauritanicus. First, A. mauritanicus plants were grown in the ‘polluted’ culture medium for seven days and were, then, substituted by Desmodesmus sp. for a further seven days (14 days in total). Heavy metals were shown to negatively affect both the growth rates and nutrient removal capacity. The sequential approach resulted in high metal removal rates in the single metal solutions up to 74% for Cu and 85% for Ni, while, in the bi-metal solutions, the removal rates were lower and showed a bias for Cu uptake. Single species controls showed better outcomes; however, further studies are necessary to investigate the behavior of new species.


2014 ◽  
Vol 4 (1) ◽  
pp. 193 ◽  
Author(s):  
Gideon Ramtahal ◽  
Ivan Chang Yen ◽  
Isaac Bekele ◽  
Frances Bekele ◽  
Lawrence Wilson ◽  
...  

<p>The determination of heavy metals in cocoa beans and chocolates is of great importance, due to increasingly stringent regulations being implemented by international legislative bodies and chocolate manufacturers, to protect the health of their consumers. While various techniques exist for heavy metal analyses in cocoa, this study developed a cost-effective, accurate and precise method capable of processing up to 120 samples per batch for the determination of cadmium, copper, nickel and zinc. For sample extractions, a normal laboratory hot plate and locally fabricated high-capacity digestion blocks were used, instead of dedicated block digestion or microwave digestion systems. In addition, only concentrated nitric acid was used, instead of mixed reagents used in standardized methods, for metal extractions from samples, with a sample: extractant ratio of 0.5 g : 10 mL, digestion at 130 ºC, followed by filtration and analysis by flame atomic absorption spectrophotometry. The method was validated with Certified Reference Materials, with heavy metal recoveries generally &gt;95%. Additionally, an in-house quality control sample of ground cocoa nib analyzed together with the Certified Reference Materials was used to monitor the consistency of analyses of heavy metals in cocoa bean samples.</p>


2021 ◽  
Vol 3 ◽  
Author(s):  
Subhrangshu Mandal ◽  
Kunal Kumar Saha ◽  
Narayan Chandra Mandal

Over the past few decades, the massive increase in anthropogenic activity and industrialization processes has increased new pollutants in the environment. The effects of such toxic components (heavy metals, pesticides, etc.) in our ecosystem vary significantly and are of significant public health and economic concern. Because of this, environmental consciousness is increasing amongst consumers and industrialists, and legal constraints on emissions are becoming progressively stricter; for the ultimate aim is to achieve cost-effective emission control. Fortunately, certain taxonomically and phylogenetically diverse microorganisms (e.g., sulfur oxidizing/reducing bacteria) are endowed with the capability to remediate such undesired components from diverse habitats and have diverse plant-growth-promoting abilities (auxin and siderophore production, phosphate solubilization, etc.). However, the quirk of fate for pollutant and plant-growth-promoting microbiome research is that, even with an early start, genetic knowledge on these systems is still considered to be in its infancy due to the unavailability of in-depth functional genomics and population dynamics data from various ecosystems. This knowledge gap can be breached if we have adequate information concerning their genetic make-up, so that we can use them in a targeted manner or with considerable operational flexibility in the agricultural sector. Amended understanding regarding the genetic basis of potential microbes involved in such processes has led to the establishment of novel or advanced bioremediation technologies (such as the detoxification efficiency of heavy metals), which will further our understanding of the genomic/genetic landscape in these potential organisms. Our review aimed to unravel the hidden genomic basis and eco-physiological properties of such potent bacteria and their interaction with plants from various ecosystems.


2021 ◽  
Vol 16 (AAEBSSD) ◽  
pp. 77-85
Author(s):  
Sridevi Tallapragada ◽  
Rajesh Lather ◽  
Vandana ◽  
Gurnam Singh

Phytoremediation is the plant-based technology that has emerged as a novel cost effective and ecofriendly technology in which green plants are used for extraction, sequestration and/or detoxification of the pollutants. Plants possess the natural ability to degrade heavy metals and this property of plants to detoxify contaminants can be used by genetic engineering approach. Currently, the quality of soil and water has degraded considerably due heavy metal accumulation through discharge of industrial, agricultural and domestic waste. Heavy metal pollution is a global concern and a major health threat worldwide. They are toxic, and can damage living organisms even at low concentrations and tend to accumulate in the food chain. The most common heavy metal contaminants are: As, Cd, Cr, Cu, Hg, Pb and Zn. High levels of metals in soil can be phytotoxic, leading to poor plant growth and soil cover due to metal toxicity and can lead to metal mobilization in runoff water and thus have a negative impact on the whole ecosystem. Phytoremediation is a green strategy that uses hyperaccumulator plants and their rhizospheric micro-organisms to stabilize, transfer or degrade pollutants in soil, water and environment. Mechanisms used to remediate contaminated soil includes phytoextraction, phytostabilization, phytotransformation, phytostimulation, phytovolatilization and rhizofiltration. Traditional phytoremediation method presents some limitations regarding their applications at large scale, so the application of genetic engineering approaches such as transgenic transformation, nanoparticles addition and phytoremediation assisted with phytohormones, plant growth-promoting bacteria and Arbuscular mycorrhizal fungi (AMF) inoculation has been applied to ameliorate the efficacy of plants for heavy metals decontamination. In this review, some recent innovative technologies for improving phytoremediation and heavy metals toxicity and their depollution procedures are highlighted.


2019 ◽  
Vol 16 (1) ◽  
pp. 01-13 ◽  
Author(s):  
Pragya Goyal ◽  
Pranoti Belapurkar ◽  
Anand Kar

Microbial assisted remediation is the ray of hope in the current scenario of tremendous heavy metal pollution. The indiscriminate release of heavy metal laden industrial effluents in the water bodies and soil is now manifesting itself in the form of life threatening health hazards to humans. The conventional heavy metal remediation strategies are not only expensive but are ineffective in low metal concentrations. Microbial assisted remediation of heavy metals has come forward as the cheap and easy alternative. Amongst the various bacterial genera actively involved in bioremediation of cadmium and nickel in the environment, genus Bacillus has shown remarkable ability in this respect owing to its various biochemical and genetic pathways. It can perform bioremediation using multiple mechanisms including biosorption and bioaccumulation. This genus has also been able to reduce toxicity caused by cadmium and nickel in eukaryotic cell lines and in mice, a property also found in probiotic genera like Lactobacillus and Bifidobacterium. This paper reviews the role of environmentally present and known probiotic species of genus Bacillus along with different probiotic genera for their various mechanisms involved for remediation of cadmium and nickel.


Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 896 ◽  
Author(s):  
Shafaqat Ali ◽  
Zohaib Abbas ◽  
Mahmoud F. Seleiman ◽  
Muhammad Rizwan ◽  
İlkay YAVAŞ ◽  
...  

Unexpected biomagnifications and bioaccumulation of heavy metals (HMs) in the surrounding environment has become a predicament for all living organisms together with plants. Excessive release of HMs from industrial discharge and other anthropogenic activities has threatened sustainable agricultural practices and limited the overall profitable yield of different plants species. Heavy metals at toxic levels interact with cellular molecules, leading towards the unnecessary generation of reactive oxygen species (ROS), restricting productivity and growth of the plants. The application of various osmoprotectants is a renowned approach to mitigate the harmful effects of HMs on plants. In this review, the effective role of glycine betaine (GB) in alleviation of HM stress is summarized. Glycine betaine is very important osmoregulator, and its level varies considerably among different plants. Application of GB on plants under HMs stress successfully improves growth, photosynthesis, antioxidant enzymes activities, nutrients uptake, and minimizes excessive heavy metal uptake and oxidative stress. Moreover, GB activates the adjustment of glutathione reductase (GR), ascorbic acid (AsA) and glutathione (GSH) contents in plants under HM stress. Excessive accumulation of GB through the utilization of a genetic engineering approach can successfully enhance tolerance against stress, which is considered an important feature that needs to be investigated in depth.


2017 ◽  
Vol 7 (14) ◽  
pp. 71-83
Author(s):  
Omolara Titilayo Aladesanmi ◽  
Femi Kayode Agboola ◽  
Rapheal Emuebe Okonji

Background. Many natural aquatic bodies have been contaminated with heavy metals released from domestic, industrial and other anthropogenic activities. Fish are an important bioindicator species and play an important role in the monitoring of water pollution. Objectives. This study shows the effect of heavy metals on the distribution of glutathione S-transferases (GST), catalase, rhodanese and 3-mercaptopyruvate sulphur transferase (3-MST) isolated from the liver, gills, fins and muscle of Clarias gariepinus. Methods . Glutathione S-transferase, catalase, rhodanese and 3-mercaptopyruvate S-transferase enzymes were isolated from the liver and gills of fish by homogenization of each tissue (with specific buffers for each enzyme) and centrifugation. Serial dilutions of the crude enzymes were then assayed for residual enzymatic activities using standard enzyme assay protocol. Results. The results showed heavy metals in the liver and muscle of the investigated fish. This study indicated significant accumulation of heavy metals in the tissues/organ of the fish from Ilesha, Osogbo and Yakoyo fish ponds. These are three main towns in Osun State where the major occupation is fish farming. The relationship between enzymatic activities and heavy metal content in C gariepinus tissue showed positive and significant (p&lt;0.05) correlations between lead (Pb) and GST as well as chromium (Cr) and GST. This implies that higher concentrations of Pb and Cr induced the expression of greater GST activity in the fish tissue. Conclusions. The study concluded that the pattern of response of GST, catalase, rhodanese and 3-MST activities in the various organs/tissues of C gariepinus to the heavy metals suggests that the excitation or inhibitions of their activities are organ specific. Further biochemical studies of fish tissues/organs are needed to characterize the enzymatic changes associated with heavy metal pollution. Competing Interests: The authors declare no competing financial interests


Author(s):  
Jianghong Liu ◽  
Jian Xue ◽  
Dandan Yuan ◽  
Xiaohang Wei ◽  
Huimin Su

Heavy metal pollution has pervaded many parts of the world, especially developing countries such as China. The discharge of wastewater containing heavy metals will cause soil pollution for a long time and harm to human health. Soil washing is an environmentally feasible and cost-effective approach for the clean-up of sites contaminated with heavy metals. As a relatively environmental protection agent, surfactants are widely used in soil washing. This paper generalized the methods of remediation of soil from heavy metals, expounded the mechanisms of soil washing by surfactant and the types of surfactants and summarized the application of different surfactants in washing heavy metals from soil. Finally, the application prospects and development trends of surfactant washing heavy metals from soil have been prospected.


Sign in / Sign up

Export Citation Format

Share Document