Biological Remediation Technologies Research Articles

BIOREMEDIATION: A SUPERIOR ALTERNATIVE FOR REMEDIATING TANNERY EFFLUENT-CONTAMINATED SOIL

Tannery effluent poses significant risks to soil health, primarily through contamination with heavy metals like chromium, sulphides, and persistent organic pollutants (POPs). These toxic substances inhibit microbial activity, reducing nutrient cycling and organic matter decomposition essential for soil fertility. Beneficial microorganisms, including nitrogen-fixing bacteria, are particularly affected, leading to altered microbial communities dominated by less advantageous, metal-tolerant species. Accumulation of POPs and heavy metals disrupts soil enzymatic activities, interferes with plant root growth, and complicates remediation efforts due to pollutant migration to groundwater and potential entry into the food chain. Prolonged exposure to such contaminants diminishes soil fertility, reduces resilience, and disrupts ecosystem services, posing threats to agricultural productivity and environmental health. This review was aimed to outline what made bioremediation a superior treatment technology among other methods used in remediating tannery effluent contaminated soil. Efforts to mitigate tannery effluent impacts involve a combination of physical, chemical, and biological remediation technologies. Physical methods like soil washing, flushing, and thermal desorption focus on removing or isolating contaminants, while chemical approaches such as oxidation, reduction, and stabilization transform pollutants to less harmful forms or immobilize them. Biological remediation leverages microorganisms and plants to detoxify contaminants sustainably. Bioremediation strategies with aid of bioaugmentation and biostimulation do enhance microbial activity to address organic and inorganic pollutants effectively more than physical and chemical methods. Another excellent bioremediation technology called phytoremediation can also address organic and inorganic pollutants effectively, Achieving better remediation technique should be coupled with stringent industrial regulations, sustainable tanning methods, and stakeholder awareness

Long-term comparison of the performance of biostimulation and phytoextraction in soil contaminated with diesel and heavy metals

Long-term comparison of the performance of biostimulation and phytoextraction in soil contaminated with diesel and heavy metals

Study of biological remediation technologies in relation to the quality and quantity of sunflower (Helianthus annuus L.) crop along with the restoration of metal contaminated soil

Study of biological remediation technologies in relation to the quality and quantity of sunflower (Helianthus annuus L.) crop along with the restoration of metal contaminated soil

Remediation Technologies for Polluted Sites: Review

A polluted site can have serious consequences for human health, water supplies, ecosystems, and even building structures, which is why various safeguards have been put in place to address contamination issues. This systematic review will conduct a literature search on remediation technologies for polluted sites. Sources of information and search, eligibility and exclusion criteria, and a systematic searching strategy are used to retrieve articles related to remediation technologies for polluted sites. Heavy metal pollution in the soil is a worldwide problem that humanity is attempting to address. Heavy metal pollution can be found in varying degrees in the soils of all countries worldwide. Heavy metal-contaminated soil is cleaned using chemical, physical, and biological remediation technologies. Many methods have been developed over the last thirty years to remediate oil-contaminated soil. Biological techniques such as phytoremediation and land farming are used to remediate oil-contaminated soil. Groundwater poisoning by heavy metals, which can come from natural soil sources or man-made sources, is a major public health concern. Because contaminated groundwater serves as a source of drinking water for billions of people worldwide, remediation is a top priority. The best remediation technologies for containing groundwater water are pump and treatment, excavation method, permeable reactive barrier, air sparging, electrokinetic remediation, chemical oxidation, and bioremediation. The selection of remediation methods necessitates a thorough examination of technological effectiveness and economic environmental safety. Personal and trial examinations of remediation advancements continue. As a result, in future research, investigating the zero-valent iron powder restoration method in conjunction with other restoration methods to treat soil heavy metal pollution is critical to soil restoration and ecological restoration, revealing the main influencing factors of the restoration process as well as the promotion and implementation of this method. Keywords: - Remediation, Polluted site, Technology DOI: 10.7176/JEES/12-12-02 Publication date: December 31 st 2022

Bio-removal of emerging pollutants by advanced bioremediation techniques

Bio-removal of emerging pollutants by advanced bioremediation techniques

A Review on Biotechnological Approaches Applied for Marine Hydrocarbon Spills Remediation.

The increasing demand for petroleum products generates needs for innovative and reliable methods for cleaning up crude oil spills. Annually, several oil spills occur around the world, which brings numerous ecological and environmental disasters on the surface of deep seawaters like oceans. Biological and physico-chemical remediation technologies can be efficient in terms of spill cleanup and microorganisms—mainly bacteria—are the main ones responsible for petroleum hydrocarbons (PHCs) degradation such as crude oil. Currently, biodegradation is considered as one of the most sustainable and efficient techniques for the removal of PHCs. However, environmental factors associated with the functioning and performance of microorganisms involved in hydrocarbon-degradation have remained relatively unclear. This has limited our understanding on how to select and inoculate microorganisms within technologies of cleaning and to optimize physico-chemical remediation and degradation methods. This review article presents the latest discoveries in bioremediation techniques such as biostimulation, bioaugmentation, and biosurfactants as well as immobilization strategies for increasing the efficiency. Besides, environmental affecting factors and microbial strains engaged in bioremediation and biodegradation of PHCs in marines are discussed.

Prospects in the bioremediation of petroleum hydrocarbon contaminants from hypersaline environments: A review.

Hypersaline environments are underappreciated and are frequently exposed to pollution from petroleum hydrocarbons. Unlike other environs, the high salinity conditions present are a deterrent to various remediation techniques. There is also production of hypersaline waters from oil-polluted ecosystems which contain toxic hydrophobic pollutants that are threat to public health, environmental protection, and sustainability. Currently, innovative advances are being proposed for the remediation of oil-contaminated hypersaline regions. Such advancements include the exploration and stimulation of native microbial communities capable of utilizing and degrading petroleum hydrocarbons. However, prevailing salinity in these environments is unfavourable for the growth of non-halophylic microorganisms, thus limiting effective bioremediation options. An in-depth understanding of the potentials of various remediation technologies of hydrocarbon-polluted hypersaline environments is lacking. Thus, we present an overview of petroleum hydrocarbon pollution in hypersaline ecosystems and discuss the challenges and prospects associated with several technologies that may be employed in remediation of hydrocarbon pollution in the presence of delimiting high salinities. The application of biological remediation technologies including the utilization of halophilic and halotolerant microorganisms is also discussed.

Reclamation of Abandoned Mine Soil: A Review on Properties and Remediation Techniques

Abstract: The environment which is a part of ecosystem is being polluted due to urbanization, rapid industrialization increased demands for resources in our day to day lives have left no resources untouched. Various anthropogenic activities such as mining and milling operations, which include grinding, screening, concentrating ores and removal of tailings, disposal of mine and mill waste water release toxic metals into the natural environment affecting the lithosphere. Reclamation is the process of restoring the environmental soundness of these distressed mine lands. It consists of governing all kinds of physical, chemical and biological inconvenience of land area or soil such as fertility, pH, microbial activities and different soil nutrient cycles that make the destructed land soil fertile. The main aim of the reclamation is to bring back the fertility of soil by increasing its N, P, K values and Carbon contents. There are various remediation technologies available for removal of heavy metal from contaminated mine soil, in this paper we have discussed in-situ remediation, physical remediation, chemical remediation and biological remediation technologies which are implemented across the globe.

THE REMEDIATION OF AGRICULTURAL LAND CONTAMINATED BY HEAVY METALS

The presence of heavy metals in an agricultural land is the primary cause of food product toxicity of a herbal and animal origin associated with a contaminated agricultural land. The anthropogenic sources of pollution, especially the fertilizers and pesticides in agriculture, are the primary sources of agricultural land contamination with heavy metals. The heavy metals whose monitoring is prescribed by the current legislation of the Republic of Croatia include cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb) and zinc (Zn). The aim of this paper is to provide a review of heavy metals that cause contamination of an agricultural land, as well as a review of remediation technologies applied to reduce contamination. Furthermore, the paper considers three groups of remediation technologies, i.e., the biological, chemical, and physical ones, analyzing the applicability, efficiency, cost-effectiveness and accessibility in Croatia to encourage their wider implementation. The biological remediation technologies, also known as phytoremediation, met the set criteria the most, which currently renders them most applicable to the mildly‐ and moderately‐contaminated agricultural land. The chemical and physical remediation technologies are generally more suitable for the remediation of a severely contaminated agricultural land, applied individually or in combination with the phytoremediation methods due to the high cost.

Cytochrome P450-mediated mycotoxin metabolism by plant-feeding insects.

Mycotoxins are secondary metabolites produced primarily by filamentous fungi that when consumed cause pathological responses in animal hosts or consumers. Defined functionally rather than structurally, mycotoxins derive from numerous primary metabolic pathways. Through opportunistic or mutualistic associations, insect herbivores inflict damage that can predispose plants to infection by mycotoxin-producing phytopathogens, resulting in economically significant contamination. The few cytochrome P450 subfamilies implicated in mycotoxin detoxification by insects, including CYP6 and CYP9, are also known to detoxify phytochemicals. Some insect P450s bioactivate, rather than detoxify, mycotoxins, suggestive of an 'escalation' in arms-race interactions between these herbivores and fungi. Characterizing insect P450s that detoxify mycotoxins can be useful for developing biological remediation technologies and for ensuring the safety of insects reared for human or livestock consumption.

Effects of Plant and Soil Amendment on Remediation Performance and Methane Mitigation in Petroleum-Contaminated Soil.

Petroleum-contaminated soil is considered among the most important potential anthropogenic atmospheric methane sources. Additionally, various rhizoremediation factors can affect methane emissions by altering soil ecosystem carbon cycles. Nonetheless, greenhouse gas emissions from soil have not been given due importance as a potentially relevant parameter in rhizoremediation techniques. Therefore, in this study we sought to investigate the effects of different plant and soil amendments on both remediation efficiencies and methane emission characteristics in dieselcontaminated soil. An indoor pot experiment consisting of three plant treatments (control, maize, tall fescue) and two soil amendments (chemical nutrient, compost) was performed for 95 days. Total petroleum hydrocarbon (TPH) removal efficiency, dehydrogenase activity, and alkB (i.e., an alkane compound-degrading enzyme) gene abundance were the highest in the tall fescue and maize soil system amended with compost. Compost addition enhanced both the overall remediation efficiencies, as well as pmoA (i.e., a methane-oxidizing enzyme) gene abundance in soils. Moreover, the potential methane emission of diesel-contaminated soil was relatively low when maize was introduced to the soil system. After microbial community analysis, various TPH-degrading microorganisms (Nocardioides, Marinobacter, Immitisolibacter, Acinetobacter, Kocuria, Mycobacterium, Pseudomonas, Alcanivorax) and methane-oxidizing microorganisms (Methylocapsa, Methylosarcina) were observed in the rhizosphere soil. The effects of major rhizoremediation factors on soil remediation efficiency and greenhouse gas emissions discussed herein are expected to contribute to the development of sustainable biological remediation technologies in response to global climate change.

Review of remediation technologies for sediments contaminated by heavy metals

Contamination of sediments with heavy metals (HMs) is a worldwide environmental issue, due to the negative ecological effects of HMs. Sediments are an important component of aquatic ecosystems, impacting the transformation and transfer of HMs in the environment. Thus, remediating sediments polluted by HMs is a crucial activity within the full aquatic ecosystem remediation process, and economical, effective, and environmentally friendly remediation techniques are urgently needed. We reviewed the existing literature on sediment remediation techniques and developments in the fields of environmental science and engineering, attempting to provide a better understanding of the advances of remediation techniques and new research directions for sediments contaminated by HMs. This review summarized remediation methods (e.g., physical–chemical strategies, biological strategies, and combined techniques) used to treat sediments contaminated with HMs. This included analyzing the mechanisms associated with biological remediation technologies and their combination with other methods. Then, the review summarized the factors influencing the selection of remediation methods and evaluated the prospects of new emerging remediation methods. Bioimmobilization techniques (e.g., phytostabilization and microorganism immobilization) have received increased attention because of their low remediation cost and environmental compatibility. Furthermore, particular attention has been paid to explore the role of sulfate-reducing bacteria in decreasing heavy metal mobility. The review provides a useful theoretical foundation and technology reference for the remediation of sediment polluted by HMs.

Degradation of the recalcitrant oil spill components anthracene and pyrene by a microbially driven Fenton reaction.

Oil spill components include a range of toxic saturated, aromatic and polar hydrocarbons, including pyrene and anthracene. Such contaminants harm natural ecosystems, adversely affect human health and negatively impact tourism and the fishing industries. Current physical, chemical and biological remediation technologies are often unable to completely remove recalcitrant oil spill components, which accumulate at levels greater than regulatory limits set by the Environmental Protection Agency. In the present study, a microbially driven Fenton reaction, previously shown to produce hydroxyl (HO • ) radicals that degrade chlorinated solvents and associated solvent stabilizers, was also found to degrade source zone concentrations of the oil spill components, pyrene (10 μM) and anthracene (1 μM), at initial rates of 0.82 and 0.20 μM h -1 , respectively. The pyrene- and anthracene-degrading Fenton reaction was driven by the metal-reducing facultative anaerobe Shewanella oneidensis exposed to alternating aerobic and anaerobic conditions in the presence of Fe(III). Similar to the chlorinated solvent degradation system, the pyrene and anthracene degradation systems required neither the continual supply of exogenous H 2 O 2 nor UV-induced Fe(III) reduction to regenerate Fe(II). The microbially driven Fenton reaction provides the foundation for the development of alternate ex situ and in situ oil and gas spill remediation technologies.

Comparative bioremediation of heavy metals and petroleum hydrocarbons co-contaminated soil by natural attenuation, phytoremediation, bioaugmentation and bioaugmentation-assisted phytoremediation

Comparative bioremediation of heavy metals and petroleum hydrocarbons co-contaminated soil by natural attenuation, phytoremediation, bioaugmentation and bioaugmentation-assisted phytoremediation

English

Oil sludge is a thick viscous mixture of sediments, water, oil and hydrocarbons, encountered during crude oil refining, cleaning of oil storage vessels and waste treatment. Polycyclic aromatic hydrocarbons (PAHs), which are components of crude oil sludge, constitute serious environmental concerns, as many of them are cytotoxic, mutagenic and potentially carcinogenic. Improper management and disposal of oil sludge causes environmental pollution. The adverse effects of oil sludge on soil ecology and fertility have been of growing interest among environmental scientist and an important consideration in the development of efficient technologies for remediation of contaminated land, with a view to making such land available for further use. Oil sludge can be treated by several methods such as physical, chemical and biological processes. The biological processes are mostly cost effective and environmentally friendly, as they are easy to design and implement, as such they are more acceptable to the public. Compost, the product of biological breakdown of organic matter is a rich source of hydrocarbon-degrading microorganisms such as bacteria and fungi. These microorganisms can degrade the oil sludge to less toxic compounds such as carbon dioxide, water and salts. Compost bioremediation, the application of composting in remediation of contaminated environment, is beginning to gain popularity among remediation scientists. The success or failure of compost bioremediation depends on a number of factors such as nutrients, pH, moisture, aeration and temperature within the compost pile. The bioavailability and biodegradability of the substrate to the degrading microorganisms also contributes to the success of the bioremediation process. This is a review on the biological remediation technologies employed in the treatment oil sludge. It further assesses the feasibility of using compost technology for the treatment of oil sludge, as a better, faster and more cost effective option. Key words: Biodegradation, bioremediation, composting, oil sludge, polycyclic aromatic hydrocarbons (PAHs).

Remediation Technologies for Marine Oil Spills: A Critical Review and Comparative Analysis

Problem statement: Anthropogenic activities pollute the oceans with oil through land run off, vessels accidents, periodic tanker discharges and bilge discharges. Oil spills are environmental disasters that impact human, plants and wild life including birds, fish and mammals. Approach: In this study, the International Guidelines for Preventing Oils Spills and Response to Disasters were reviewed and the characteristics of oil spills were discussed. The advantages and disadvantages of various oil spill response methods were evaluated. A comparative analysis were performed on the currently available remediation technologies using 10 evaluation criteria that included cost, efficiency, time, impact on wild life, reliability, level of difficulty, oil recovery, weather, effect on physical/chemical characteristics of oil and the need for further treatment. The advantages and disadvantages of each response method were used to determine the score assigned to that method. Results: There are many government regualtions for individual countries that serve as prevention mesures for oil spills in the offshore environment. They have to do with the design of equipment and machinery used in the offshore environment and performing the necessary safety inspections. The primary objectives of response to oil spill are: to prevent the spill from moving onto shore, reduce the impact on marine life and speed the degradation of any unrecovered oil. There are several physical, chemical, thermal and biological remediation technologies for oil spills including booms, skimmers, sorbents, dispersants, in-situ burning and bioremediation. Each technique has its advantages and disadvantages and the choice of a particular technique will depend on: type of oil, physical, biological and economical characteristics of the spill, location, weather and sea conditions, amount spilled and rate of spillage, depth of water column, time of the year and effectiveness of technique. Coclusion: Based on the comparative analysis, oil recovery with mechanical methods and the application of dispersants followed by bioremediation is the most effective response for marine oil spill.

Efforts to improve coupled in situ chemical oxidation with bioremediation: a review of optimization strategies

In order to provide highly effective yet relatively inexpensive strategies for the remediation of recalcitrant organic contaminants, research has focused on in situ treatment technologies. Recent investigation has shown that coupling two common treatments—in situ chemical oxidation (ISCO) and in situ bioremediation—is not only feasible but in many cases provides more efficient and extensive cleanup of contaminated subsurfaces. However, the combination of aggressive chemical oxidants with delicate microbial activity requires a thorough understanding of the impact of each step on soil geochemistry, biota, and contaminant dynamics. In an attempt to optimize coupled chemical and biological remediation, investigations have focused on elucidating parameters that are necessary to successful treatment. In the case of ISCO, the impacts of chemical oxidant type and quantity on bacterial populations and contaminant biodegradability have been considered. Similarly, biostimulation, that is, the adjustment of redox conditions and amendment with electron donors, acceptors, and nutrients, and bioaugmentation have been used to expedite the regeneration of biodegradation following oxidation. The purpose of this review is to integrate recent results on coupled ISCO and bioremediation with the goal of identifying parameters necessary to an optimized biphasic treatment and areas that require additional focus. Although a biphasic treatment consisting of ISCO and bioremediation is a feasible in situ remediation technology, a thorough understanding of the impact of chemical oxidation on subsequent microbial activity is required. Such an understanding is essential as coupled chemical and biological remediation technologies are further optimized.

Chromium in the environment: factors affecting biological remediation

Chromium, in the trivalent form (Cr(III)), is an important component of a balanced human and animal diet and its deficiency causes disturbance to the glucose and lipids metabolism in humans and animals. In contrast, hexavalent Cr (Cr(VI)) is highly toxic carcinogen and may cause death to animals and humans if ingested in large doses. Recently, concern about Cr as an environmental pollutant has been escalating due to its build up to toxic levels in the environment as a result of various industrial and agricultural activities. In this review, we present the state of knowledge about chromium mobility and distribution in the environment and the physiological responses of plants to Cr with the desire to understand how these processes influence our ability to use low cost, environmentally friendly biological remediation technologies to clean up Cr-contaminated soils, sediments, and waters. The use of biological remediation technologies such as bioremediation and phytoremediation for the cleanup of Cr-contaminated areas has received increasing interest from researchers worldwide. Several methods have been suggested and experimentally tested with varying degrees of success.

Managing Asia's environmental crisis: EQM opportunities for remediation and technology transfer

AbstractConditions of environmental pollution and degradation in Asia are among the worst in the world. Rapid economic growth and industrialization over the past half century have accelerated the pollution of air, water, and land resources in a region with the world's largest concentration of population. As the economics of Asia recover from financial crisis in the late 1990s, they will face a more serious environmental crisis in the early years of the 21st century. Remediation of soil and water contamination will become a stronger concern in the region, as the human health impacts become more visible and widespread. Although environmental remediation is only beginning to emerge in Asia as a solution to problems of natural resource degradation, the authors show how U.S. firms with experience in quality environmental management and biological remediation technologies will find new opportunities for exports and technology transfer. Environmental technology and services firms interested in Asia must understand both the opportunities for and barriers to operating in Asia.