Heavy Metal Remediation

Atmospheric heavy metal (HMs) pollution that impacts the environment and human health is one of the increasingly concerning problems in developing countries. Southeast Asia (SEA) is now described as a dynamic and rapidly developing region and is facing problems of air pollution, including HMs in the atmosphere. According to the International Cancer Research Institute (IARC), some metals (e.g., Pb, As, Ni, Cd, Hg, Cd, Cr) are particularly harmful to human health. In this chapter, we focus on the knowledge of atmospheric HMs in the SEA region over the last 15 years, in which, the potential sources and spatio temporal distribution of atmospheric HMs in SEA were discussed in detail. Research on atmospheric HMs is unevenly distributed in the SEA region and most of the studies concentrated in countries such as Thailand, Malaysia, and Vietnam. By employing multivariable models, including PCA and PMF, studies show that both anthropogenic sources (e.g., transportation, biomass burning, and industrial processes) and natural sources (e.g., volcanic eruption and dust storms) can contribute to elevated atmospheric HMs. HMs concentrations in industrial areas are often higher than in urban/background locations. On a seasonal basis, HMs concentrations in the dry season are often higher than in the rainy season. Certain knowledge gaps pertaining to atmospheric HMs in the SEA region necessitate comprehensive investigation. Specifically, there is a need for rigorous research focused on elucidating the deposition of atmospheric HMs as well as research regarding atmospheric mercury (Hg). This chapter presents scientific information on atmospheric HMs pollution in SEA from both regulatory and research perspectives. It aims to enhance the understanding of HMs contaminations in the SEA region by providing updated and rigorous scientific analysis.

Heavy metals are defined by their density, Metals with densities more than 5 g/cm³ are classified as heavy metals. According to this study, the heavy metals that pose the most risk to humans are lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As). Heavy metals may pollute water sources, harming aquatic life and rendering the water hazardous for human consumption. Anthropogenic activities have contributed more to the soil’s pollution with heavy metals and other contaminants than natural sources do. Chemical fertilizers, insecticides and herbicides with a chemical basis are increasingly being used in everyday agriculture activities all over the world. They are dispersing and depositing in water, and the environment and water are degrading, affecting aquatic life and causing sediments and deposits in bodies of water. If even tiny amounts of heavy metals like arsenic, mercury, lead, chromium, or cadmium are present, they are extremely dangerous. Atomic absorption spectrometry (AAS), neutron activation analysis (NAA), X-ray fluorescence, inductively coupled plasma optical emission spectrometry (ICPOES), atomic emission/fluorescence spectrometry, inductively coupled plasma mass spectrometry (ICP-MS), and anodic stripping voltammetry are just a few of the instruments available heavy metal concentrations can be determined using this method. Remote sensing spectra are useful to map the presence of toxic heavy metals (HMs) in soil because they give information on organic matter, Fe-oxides, and clays in soils and plant cover. Kemper and Sommer used airborne hyperspectral data to map the remaining hazardous heavy metals (HMs) in Spanish soils following a quarrying disaster. Numerous corrective action procedures are being used. Phytoremediation is one type of bioremediation that seems to be more environmentally friendly.

The rise in population and industrialization is increasing the strain on natural resources. This results in a greater need for industrial and agricultural production, which subsequently puts pressure on soil and water resources. The production of solid and liquid waste from industrial activity can contaminate soil and water sources. Such pollution is harmful to the ecosystem, including flora and fauna and human health. Heavy metal pollution poses a particularly severe environmental concern. With this study, how to manage new methods used in the reclamation of soils contaminated with heavy metals for sustainable agriculture and the importance of this process are revealed. Heavy metals, like copper, cadmium, nickel, lead, chromium, arsenic, and mercury, frequently contaminate natural assets. Heavy metal pollution can diminish crop yields and imperil the quality of soil and the environment. Biochar is soil amendments that offer practical solutions to the negative effects of heavy metals on soil, as well as to environmental health and fertility. Biochar has received significant attention in recent years due to its economical production cost and unique physicochemical properties. It is an inert substance generated from the pyrolysis of biomass, leaving behind a solid organic residue loaded with carbon. Biochar can be synthesised using various biomass sources, such as wood, crop remains, and animal waste. The typical method of obtaining biochar is pyrolysis, where organic materials undergo thermal decomposition in oxygen-depleted conditions. Organic materials are heated to temperatures exceeding 400 °C using electric heating or high-temperature media in an inert atmosphere. Notable benefits of biochar for soil and the environment include reducing heavy metal pollution, increasing soil fertility, soil quality and water retention, enhancing soil microbial activity, and decreasing greenhouse gas emissions. Accordingly, biochar presents an extraordinary potential as a soil amendment for addressing a range of environmental issues. It is a feasible and cost-efficient technique for heightening the health and fertility of soil while concurrently restricting heavy metal contamination.

Countries are searching for alternative energy sources because of the global impact of greenhouse gases and the possibility of an energy crisis. In this regard, innovative technologies like composting are becoming more and more popular around the globe as a means of getting rid of municipal solid waste in agricultural areas. Composting is a biological process that creates an earth-like structure called compost by means of microorganisms converting organic materials, such as animal excreta, sludge from biological treatment plants, leaves, paper, and food waste, among others. One benefit of composting is that it helps to keep the environment clean. Organic material is stabilized through composting. It is well known that earthworms improve the fertility of the soil and the quality of the produce that is grown there. By passing soil through their bodies, they are able to attain this increase. The worm's body goes through a number of processes with the soil that it sends into the digestive tract along with the nutrients it absorbs. The worms provide the soil with essential nutrients by releasing their excrement, which is a highly valuable fertilizer into the surrounding environment. Practically all of the minerals required for plant growth are present in this vermicompost. Vermicomposting and composting differ primarily in that vermicomposting does not undergo the thermophilic phase of composting. Additionally, as the worms’ digestive tracts process the waste to be processed, the heavy metals in it are stabilized and separated from the fertilizer during the vermicomposting process. For all of these reasons, research on vermicompost (also known as vermicomposting) and its use in rural areas has expanded both domestically and internationally in recent years. The issue of declining organic matter in agricultural soils is addressed in developed nations through the use of conventional organic fertilizers; however, vermicompost fertilizers are also an effective solution. In actuality, everything here is about preserving a healthy ecosystem for next generations by preventing chemical pollution of agricultural products and soils.

This procedure is way more economical and practical than other techniques available in the market, which is rarely explored by the research community. In India, proper waste segregation is very poor, and direct dumping into uncontaminated soil and water is dominant.  Phytoremediation can be easily installed in large areas to treat waste, and as its cost is minimal, industries and commercial colonies could approach it. Hyperaccumulators are used for this process as it has a unique defense mechanism to counter heavy metals. It absorbs toxins beyond the limit, reduces toxicity, and accumulates in the root and shoot part. Metals can be claimed after the harvesting period. Introducing bioenergy in the field of phytoremediation is a crucial approach adopted worldwide as it enhances economic values meanwhile sequestrating the heavy metals in a substantial way. It prevents soil erosion, enhancing the soil quality and reducing the carbon load from the environment.

Heavy metals refer to metals with a molecular weight of 5 times more than water. Heavy metals enter the environment through mining the metal, metal casting, and smelting industries, and they return to humans through food, meat, vegetables, and contaminated drinking water. Heavy metals are removed by physical remediation, chemical remediation, and bioremediation methods, also bioremediation is cost-effective, has easy availability, and eco-friendliness. The types of mechanism microbial bioremediation of metal are biosorption, bioaccumulation, bioleaching, biomineralization, and biotransformation. Microorganisms provide resistance to heavy metals through various mechanisms, including extracellular or intracellular sequestration, extracellular barriers, reduction, and active transport (efflux). Heavy metals affect the diversity and number of microbes in the environment, which has been studied by metagenomic methods. The consortium produces stromatolites, microbial mats, and biofilms that are resistant and bioremedicated to various metals. Microorganisms also produce nanoparticles by bioremediation of metals. Nanocomposites increase the activities of microbial biostimulation, bioaccumulation, and biotransformation.

Anthropogenic activities resulting from various industrial processes and some natural activities has caused the rise in discharge of heavy metals into the ecosystem. Environmental problems as a result of indiscriminate release of heavy metals is of significance due to the threat pose to all living biota in the environ and their perdurable character which makes them to pile-up in the energy chain and exerts their toxic consequences on all living components of the ecosystem. This necessitates urgent need to prevent their spread and elimination from the environment. The commonly used physicochemical techniques of remediation has many drawbacks that include loss of soil microbial diversity and function, secondary pollution, cost ineffectiveness, alteration of soil properties that render the soil unfit for agricultural purposes and other uses amongst others. Due to these concerns, research into the use of environmentally friendly and sustainable approaches has been on the increase. Novel prospects of employing microorganisms (bioremediation) and plants (phytoremediation, rhizoremediation) to alter or eliminate heavy metals from the environment has been identified. In this section, various plant and microbe-based processes are identified as the biotechnological strategies that are currently adopted for reduction or elimination of heavy metal from polluted areas. This present chapter also discuss the mechanisms responsible for the actualization of the identified biotechnological strategies. It is therefore encouraged to adopt the use of these bio-based approaches in large-scale treatment of heavy metal polluted sites.

Environmental contamination by heavy metals is fast becoming a worldwide concern due to their non-degradable nature that enhance their accumulation in the environment. Several conventional methods are in used for treatment of contaminated sites but these methods are usually inefficient financially and negatively impact the qualities of contaminated areas. Therefore, there is a pressing requirement for more economically viable and minimally invasive strategies for detoxifying polluted areas of heavy metals. The exploitation of biosurfactants towards removal of heavy metals from the environment is an exciting new area of research. Micelle production is the fundamental principle of biosurfactants-mediated heavy metal removal. The pace at which metals are removed from contaminated locations is related to the type of biosurfactant generated by the producer strains. Biosurfactant is known to improve heavy metal removal from the environment via a number of mechanisms, the most important of which are complexation, ion exchange, and metal solubilization. Experiments showing that biosurfactants can help remove metals from a laboratory setting pave the way for their potential use on a larger scale. This section describes the properties, classification, and screening procedures of biosurfactants and the mechanisms by which biosurfactants remove heavy metals from soils.

Pollution sources in ecosystems are mostly anthropogenic. Heavy metal contamination is one of these concerns, threatening ecosystem health, plants, humans, and animals in different concentrations. Environmental remediation techniques are the probable solution to care for these situations. Every remediation treatment demands resources and some preneeds also have some side effects. Phytoremediation is one of the categories of bioremediations, which is considered a cost-effective and eco-friendly method for techniques categories, which is considered a cost-effective and eco-friendly method for soil and water cleanup. This method could be assisted using rhizobacteria. This chapter gathers and details the different roles of rhizobacteria in the phytoremediation of heavy metals.

Heavy metal pollution poses a substantial public health hazard, manifesting in diverse toxicological effects. Conventional remediation methods, while effective, are costly and generate environmentally harmful byproducts. In response, the adoption of green technologies utilizing biological agents, such as bacteria, algae, and fungi, has gained prominence for heavy metal removal due to their cost-effectiveness and efficiency. This paper explores the field of bioremediation, explicitly focusing on removing heavy metals like Lead(II), Nickel(II), and Chromium(VI) using those microorganisms. Bioremediation offers an eco-friendly and economically viable solution to combat the adverse impacts of heavy metal pollution. The paper elucidates the intricate mechanisms employed by these microorganisms, encompassing biosorption, bioaccumulation, biotransformation, and detoxification processes, all of which enable the conversion of toxic heavy metals into non-toxic forms or their sequestration. By comprehending the complex mechanisms harnessed by bacteria, fungi, and algae, this research seeks to contribute to developing innovative and effective bioremediation strategies for heavy metal-contaminated environments, with a strong emphasis on sustainability and environmental friendliness. This study underscores the advantages and drawbacks of bioremediation as a promising technology for mitigating heavy metal pollution.

Recently, anthropogenic activities have evolved into sources of pollution, particularly when it comes to the discharge of harmful heavy metals into the natural environment. As a result, the concentration of diverse heavy metal ions in surface and ground waters significantly increases, compromising aquatic life. Given that toxic heavy metals have undesirable consequences on the health of all living things, their presence in the aquatic environment is a major worry. However, the drawbacks of conventional wastewater treatment technologies, such as their high consumption of energy, production of hazardous secondary sludge, and high operating costs, made them uneconomical and non-sustainable for developing nations. This book chapter presents and discusses the most recent developments and advances in the adsorptive removal of various heavy metals from aquatic systems through the application of low-cost adsorbents derived from agricultural waste materials. The influence of independent adsorption parameters as well as the mechanism of heavy metals removal from aqueous media have been explained using adsorption isotherm and kinetic models. This book chapter has demonstrated that the adsorptive removal of heavy metals using low-cost adsorbents derived from agricultural waste materials has several advantages. Almost all the studies on the adsorptive decontamination of various heavy metals from aqueous solutions revealed that adsorbents synthesized from agro-based materials are promising, eco-friendly, and cost-effective. However, several gaps exist, which need to be addressed to increase the application of the adsorption technology in treating industrial wastewater at a large scale. Hence, at the end of this book chapter, some future perspectives providing knowledge gaps that require consideration and further research have been enumerated.

Ever wonder why there is so much variation among adults of the same age, while there is much less variation among children of a similar age? The good news is that it's not just genetics—it’s largely to do with lifestyle. Science has shown that your chronological age and your biological age are two separate things. So, what ages you? There are a number of factors that are involved in this mysterious process. Any kind of illness or disease ages you significantly because of the stress it puts on your body; naturally, degenerative diseases are the most destructive of all. Obesity and a poor diet with high fat content (which can contribute to heart disease and cause skin cell senescence); dehydration (which is associated with chronic disease, biological ageing, increased mortality); alcohol consumption (which accelerates biological ageing), regular use of hard drugs like LSD [lysergic acid diethylamide], cocaine & heroin (which cause a decline in the brain among other organ functions); childbirth (which is associated with shorter telomere length, a marker of cellular ageing); and, other internal or external stressors like lack of physical exercise (which increases your risk of chronic diseases) and exposure to heavy metals (which can cause oxidative stress and induce cell senescence), are all contributors to ageing. What can you do to slow down ageing? Some anti-ageing tips are eating a Mediterranean diet; including organic superfoods in your daily diet; taking Greek superherbs in teas; drinking matcha green tea; and taking resveratrol supplements derived from grapes. Superfoods are generally rich in amino acids, sugars, essential fatty acids, vitamins, minerals, and antioxidants. Superherbs are rich in phytochemicals with antioxidant properties. Antioxidants help the body to eliminate free radicals, which contribute to ageing by causing cellular damage and oxidative stress. They can also be involved in triggering cancer. Matcha green tea contains antioxidants (polyphenols) that reduce UV damage in your skin and resveratrol is an antioxidant that scavenges free radicals, which contribute to ageing in the skin. Both are known to have anti-cancer qualities, too, since the generation of free radicals can activate apoptotic pathways resulting in carcinogenesis.

Bioindicators are living organisms used to predict the level of environmental pollution in a certain area. These organisms and their products are sensitive to surrounding changes in the concentrations of toxic components that, whether due to geographical or anthropogenic origin, can increase their presence. High agricultural, mining, and industrial activity can be sources of chemical contaminants, among these, toxic metals are the most common. Contamination with heavy metals is a public health concern because they can trigger different pathologies associated with their exposure. This is why constant monitoring is important to maintain nce doses below the limits recommended by international regulations. In recent years, bee products have been suggested as bioindicators of contamination of toxic compounds, among them, the most susceptible is propolis. This research aims to analyze the main studies that propose propolis as a bioindicator of contamination with toxic metals.

Ecotechnologies are crucial in reducing water, soil, and air pollution. With increasing concern over environmental degradation and its detrimental effects on human health, adopting sustainable practices that mitigate pollution and promote a healthier ecosystem has become imperative. Ecotechnologies offer innovative solutions that address pollution issues and contribute to our planet’s sustainability. These technologies encompass a range of approaches, such as filtration and treatment with natural coagulants that remove contaminants and provide clean water for reuse, enhancing economic efficiency. Additionally, soil remediation techniques can help restore polluted land by eliminating toxins and promoting healthy vegetation growth. Remediating soil and water can be done using physical, chemical, and biological technologies. Implementing these ecotechnologies can pave the way for a greener future and ensure the environment’s and humanity’s long-term well-being. Ecotechnologies such as filtration with nano-ceramic oxide utilization of natural coagulants can help reduce GHGS (Green House Gases) to synergetic climate change. Renewable options such as phyto and bioremediation techniques can also aid in better resource management. Furthermore, adopting ecotechnologies can lead to a more sustainable and resilient society, as people sustainably utilize the resources and risks related to the environment. Overall, ecotechnologies are crucial for achieving sustainability and prosperity.