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About this book

Achieving environmental sustainability with rapid industrialization is currently a major global challenge. Industries are the key economic drivers, but are also the main polluters as untreated/partially treated effluents from industry are usually discharged into the aquatic environment or dumped. Industrial effluents often contain highly toxic and hazardous pollutants, which cause ecological damage and present and health hazards to living beings. As such, there is a pressing need to find ecofriendly solutions to deal with industrial waste, and to develop sustainable methods for treating/detoxifying waste before it’s released into the environment. As a low cost and eco-friendly clean technology, bioremediation can offer a sustainable alternative to conventional remediation technologies for the treatment and management of industrial wastes.

This book (Volume II) describes the role of biological agents in the degradation and detoxification of organic and inorganic pollutants in industrial wastes, and presents recent bioremediation approaches for waste treatment and management, such as constructed wetlands, electro- bioremediation and nano-bioremediation, as well as microbial fuel cells. It appeals to students, researchers, scientists, industry professionals and experts in the field of microbiology, biotechnology, environmental sciences, eco-toxicology, environmental remediation and waste management and other relevant areas who are interested in biodegradation and bioremediation of industrial wastes for environmental safety.

Table of Contents


Chapter 1. Genetically Modified Organisms (GMOs) and Their Potential in Environmental Management: Constraints, Prospects, and Challenges

Increasing environmental contamination with highly toxic chemicals is warning us to find sustainable technologies to protect the environment and human health, which is a key challenge of the current scenario. A variety of physicochemical technologies are currently being applied presently to decontaminate the environment to safeguard the environment and human health. However, these technologies are costly and chemical-consuming, thus causing secondary pollution and, hence, are not environmental-friendly. As an alternative approach, bioremediation technologies using microbes and plants and their enzymes are currently viewed as eco-friendly and most sustainable technologies due to their self-sustainable and low-cost nature. But sometimes bioremediation technologies are get limited by low degradability/accumulability of microbes and plants, respectively. To overcome these limitations, genetic engineering approaches are highly decisive to design the transgenic microbes and plants for the enhanced biodegradation and biodetoxification of environmental pollutants for sustainable development. Genetically modified organisms (GMOs) offer great potential for environmental remediation, and hence, in this chapter, we focused on the applications of GMOs in the environmental management with risks involved, constraints, and challenges faced by researchers in the release of GMOs for field applications.
Gaurav Saxena, Roop Kishor, Ganesh Dattatraya Saratale, Ram Naresh Bharagava

Chapter 2. Advances in Bioremediation of Toxic Heavy Metals and Radionuclides in Contaminated Soil and Aquatic Systems

Metals are used in several products essential to humans. However, processes for extraction of the metals generate effluents containing chemical by-products many of which are toxic to living organisms and are disruptive to ecosystems. Processes used in the creation of useful products from the metals leave a legacy of pollution that may take generations to clear. Metals such as mercury, cadmium, lead, chromium, and uranium, and a range of metalloids such as arsenic and selenium, are widely known for their acute toxicity at high doses and carcinogenicity at low doses. Several technologies for treatment of land and water that have been contaminated with toxic heavy metals have been proposed. Other metallic elements, although possessing no significant chemical toxicity to organisms, occur as radioactive isotopes that impart oxidative stress on organisms leading to increased incidence of mutations and carcinomas in animal tissue. The main difficulty in the treatment of metals is that the metals cannot be degraded or mineralized as is the case with organic pollutants. Metallic elements can only be oxidized or reduced to forms that are less mobile and easier to extract from the environment. This chapter is compiled from information from projects in which metals were either oxidized or reduced to less mobile and less toxic states using pure or consortium cultures of bacteria followed by immobilization or extraction using physical or biological media. The uptake of metals for reuse was attempted using bioengineered molecular adsorbents on cell surfaces. The latter process was developed to facilitate selective uptake of different metallic species as a low energy biorefinery.
Evans M. Nkhalambayausi-Chirwa, Pulane Elsie Molokwane, Tshilidzi Bridget Lutsinge, Tony Ebuka Igboamalu, Zainab S. Birungi

Chapter 3. Phycoremediation: Algae as Eco-friendly Tools for the Removal of Heavy Metals from Wastewaters

Phycoremediation is a potential tool to eradicate the excess toxics (heavy metal and organic contaminants) from the industrial waste stream. The algal species are a promising, eco-friendly, and sustainable move toward a possible advantage to enhance the algal cultivation which in turn magnifies the economics of algal-based value-added products. Therefore, algae have been documented as a sustainable and inexpensive vector for detoxification of noxious waste-loaded industrial waste stream. Algal species may bind up to 10% of their biomass as metals. Various physical and chemical methods used for this purpose suffer from serious limitations like high cost, high energy input, alteration of basic properties, and disturbance in native flora. In contrast, phycoremediation provides a new insight/dimension for this problem by perceiving it as cost-effective, efficient, novel, eco-friendly, and solar-driven technology with good public acceptance. The mechanism for the removal of heavy metal through alga works on the principle of adsorption onto the cell surface which is independent of cell metabolism and absorption or intracellular uptake which depends on cell metabolism. So, their ability to adsorb and metabolize is associated with their large surface/volume ratios; the presence of high-affinity, metal-binding groups on their cell surfaces; and efficient metal uptake and storage systems. Hence, the present review article deals with the basic mechanism of algal-based heavy metal removal strategies with the effect of physicochemical parameters. Use of transgenic approaches to further enhance the heavy metal specificity and binding capacity of algae with the objective of using these algae for the treatment of heavy metal-contaminated wastewater is also focused in this article.
Shamshad Ahmad, Arya Pandey, Vinayak Vandan Pathak, Vineet Veer Tyagi, Richa Kothari

Chapter 4. Recent Advances in Phytoremediation of Toxic Metals from Contaminated Sites: A Road Map to a Safer Environment

Toxic contaminants, or metal and metal-containing compounds, that are released into the environment from various anthropogenic sources cause severe environmental problems by destroying soil fertility, causing scarcity of resources as well as affecting human health. Thus, remediating environmental pollution, especially heavy metal contamination, is necessary in overcoming negative impacts on ecosystem health. Heavy metal (HM) contaminants threaten both human and environmental health. One report states there are more than 1.7 million metal-contaminated sites in central and eastern European countries that require appropriate reclamation. It was also observed that severe soil and water pollution in developing countries such as China, Pakistan, India, and Bangladesh results from small industrial effluent outputs over and near agricultural areas. Phytoremediation, although it is not new, is an efficient method to clean up toxic contaminants by employing different plant species. Although this technology is successful at the laboratory level, reports underlining the unsuccessful and inconclusive attempts in its use at the field level encouraged us to critically access why it is not satisfactory in the field, and also to find evidence that it is a promising remedial strategy without emphasizing negative perceptions. Analyzing the previous reports suggests two main themes for our attention. (1) Plant stress factors pose challenges in field application, although such were negligible with laboratory and greenhouse acclimatization. (2) Methods of phytoremediation should be assessed because often the decrease in contaminants is not adequate to demonstrate the occurrence of active remediation. Keeping these points in mind, this chapter focuses on the challenges in remediation, emphasizing rhizoremediation with detailed approaches in advanced technologies to confer environmental safety and assure human health.
Mukesh Kumar Awasthi, Di Guo, Sanjeev Kumar Awasthi, Quan Wang, Hongyu Chen, Tao Liu, Yumin Duan, Parimala Gnana Soundari, Zengqiang Zhang

Chapter 5. Emerging and Ecofriendly Technologies for the Removal of Organic and Inorganic Pollutants from Industrial Wastewaters

Environmental pollution is one of the major problems of the current world, and providing a sustainable solution to manage pollution is a key challenge. Industries are mainly responsible for the environmental pollution as they discharge highly toxic pollutants in the receiving environment and provide chance for exposure to mankind and, thus, may create toxicity in humans and animals. The physicochemical methods used for the removal of a variety of organic and inorganic pollutants from industrial wastewater are costly and environmentally destructive and may create secondary pollution and, thus, ultimately deter the environmental quality. To overcome these problems, various emerging and ecofriendly technologies are becoming popular for the removal of various pollutants from industrial wastewaters. Therefore, this chapter provides an overview of the various emerging and ecofriendly technologies for the removal of organic and inorganic pollutants from industrial wastewaters with their merits and demerits.
Gaurav Saxena, Surya Pratap Goutam, Akash Mishra, Sikandar I. Mulla, Ram Naresh Bharagava

Chapter 6. Constructed Wetlands: A Clean-Green Technology for Degradation and Detoxification of Industrial Wastewaters

Constructed wetlands (CWs) have played a significant role in the purification and treatment of domestic, mining, agricultural, and industrial wastewater in the last few decades. CWs are designed and constructed on engineered systems to develop the natural processes involving wetland soils, flora, and their related microbial accumulations to support wastewater treatment. The CWs, therefore, present environmentally friendly, cost-effective, and favorable substitute for industrial wastewater treatment. Several techniques have been used in the removal of contaminants from CWs such as filtration, sedimentation, adsorption, volatilization, phyto-accumulation, and microbial activity. In the past, CWs have played efficient role in the removal of toxic metals, hydrocarbons, pharmaceuticals, and dyes from wastewater. However, the efficiency mainly depends on initial concentrations of contaminants, plant types, plant microbes’ interactions, climatic condition and flow rate of wastewater etc. The overall conclusion of this book chapter will contribute to the development of phyto-technology for industrial wastewater and other associated industrial problems.
Sardar Khan, Javed Nawab, Muhammad Waqas

Chapter 7. Nano-bioremediation: An Innovative Remediation Technology for Treatment and Management of Contaminated Sites

As every method has its own benefits and setbacks, the integration of remediation methods could be thought of as a solution to tackle remediation problems. Integrated approaches could overcome the disadvantages of individual technologies and provide a better alternative to conventional remediation methods. Nano-bioremediation is one of such kind of methods which received a lot of attention in the past few years. It aims at reducing the contaminant concentrations to risk-based levels, alleviating the additional environmental impacts simultaneously. This method brings the benefits of both nanotechnology and bioremediation together to achieve a remediation that is more efficient, less time taking, and environment friendly than the individual processes. The present chapter provides a brief account of nanotechnology and variety of nanostructured materials reported for removing organic and inorganic contaminants from environmental matrices followed by detailed description of nano-bioremediation technique, its process, and applications.
Ritu Singh, Monalisha Behera, Sanjeev Kumar

Chapter 8. Electro-bioremediation: An Advanced Remediation Technology for the Treatment and Management of Contaminated Soil

The world’s soil is being contaminated by various influences such as urbanization and industrial activities, for instance, the uncontrolled discharge of industrial wastewater. This chapter is mainly focused on electrokinetic (EK) techniques for remediation of soil polluted by the textile industry. Electrokinetic technology is employed for the removal of heavy metals and organics by applied direct electric current, which may induce the movement of pollutants from the matrix. However, so far only limited studies are available about the treatment of textile industry-contaminated soil. The present article describes approaches that can be utilized for the treatment of soils polluted by organic or inorganic compounds. Therefore, the EK removal of heavy metals, inorganic ions, and various textile dye contaminants is summarized, and the state-of-the-art is reviewed along with future trends for EK remediation of contaminated soil.
Sivasankar Annamalai, Maruthamuthu Sundaram

Chapter 9. Microbial Fuel Cell (MFC): An Innovative Technology for Wastewater Treatment and Power Generation

Microbial fuel cells (MFCs) have been nominated as new alternatives and novel opportunities which are able to convert biodegradable organic matters (as substrates) into green electricity with the aim of different types of active microorganisms as active biocatalysts. In terms of configurations, one-chambered MFCs (OC-MFCs), dual-chambered MFCs (DC-MFCs), tubular, H-type, upflow MFCs, and stacked ones would be introduced each for specific objectives. Basically, MFC configuration consists of a biological anode and an abiotic cathode chamber separated by a proton exchange membrane. Direct production of electricity out of substrates, enabling to be operated efficiently at an ambient temperature, and expanding the diversity of fuels used as energy requirements are some of the most praiseworthy advantages of MFCs. Due to electron and proton release resulted by oxidized substrates in anode compartment, sufficient information about electron transfer mechanisms of microorganisms is essential to reach raising amount of energy produced by an MFC system and to find out the theory about their operation. In the 1980s, scientists have figured out that adding some electron mediators causes an incredible enhancement in power output and current density of mentioned technology. By this demonstration, the mediator acts as a movable agent which transports electrons between electrode and bacteria in anode part. Moreover, the most useful applications of MFCs can be classified into four significant categories. They have the ability to be used for electricity production, generation of biological hydrogen, and wastewater treatment (WWT) plants. Besides, MFCs was used as power generator for sensors and biosensors or serve as biosensors themselves. Hence, use of MFCs in water quality improvement which is related to WWT has attracted many scientists all over the world over recent years. Consequently, by using these novel technologies, online monitoring of various parameters related to water quality such as biological oxygen demand, toxicity, and total organic carbon is achievable.
Mostafa Rahimnejad, Maryam Asghary, Marjan Fallah

Chapter 10. Functional Diversity of Plant Endophytes and Their Role in Assisted Phytoremediation

The functional diversity term helps to understand the biological complexity through the wide range of interactions that organisms show on communities and ecosystems as they may interact. In a particular manner, organisms may have attributes or characteristics that define their role within the ecosystems. The purpose of this review is to analyze the importance of plant growth-promoting traits of endophyte bacteria that define the functional diversity of them in their relationships with plants in assisted phytoremediation techniques.
Angélica Leonor Guerrero-Zúñiga, Eugenia López-López, Aída Verónica Rodríguez-Tovar, Angélica Rodríguez-Dorantes

Chapter 11. Toxic Metals in Industrial Wastewaters and Phytoremediation Using Aquatic Macrophytes for Environmental Pollution Control: An Eco-Remedial Approach

Toxic pollutants contaminate water by discharging wastewater generated through municipal, industrial, and landfill site waste, etc. It is emerging as a worldwide problem as it enormously affects human, fauna, and flora health of receiving water. During last few decades, the exponential population growth, productivity variation and consumption rates, and resources exploitation along with rapid industrial and technical development are seen as major contributors that accompany water pollution. Wastewater treatment has been a problem for mankind since the discovery of additional environmental problems caused by wastes discharge into surface waters was done. Though control and prevention technologies are being applied to most of these industrial and municipal sources and there is availability of a wide range of wastewater treatment technologies for restoring and maintaining the biological, chemical, and physical quality of wastewaters, still there is a staggering amount of these agents released into the environment. Another major proven threat to water is heavy metal toxicity with several associated health risks. Although they do not play any big biological role, their trace present in certain form can harm the human body and its proper functioning. This chapter discusses wastewater characteristics, toxic metals added to water, the role of plants in constructed wetlands in removal of various pollutants to remediate the wastewaters from various sources, and constraints and future of constructed wetland as a cleanup technique in wastewater remediation.
Mansi Rastogi, Meenakshi Nandal

Chapter 12. Microalgae: An Eco-friendly Tool for the Treatment of Wastewaters for Environmental Safety

Algae-based wastewater treatment can provide renewable biomass generation for sustainable bioenergy production while treating wastewater as a growth medium for algae cultivation. In addition, algae are excellent at sorbing and/or degrading inorganic materials (e.g., heavy metals) and emerging contaminants (e.g., endocrine-disrupting chemicals (EDCs)), indicating that utilizing an algae-based treatment process is one of emerging strategies for advanced wastewater treatment as an eco-friendly way. Economic advantages and environmental safety associated with algae-based wastewater treatment also constitute a driving force for its utilization in biofuel feedstock generation or fertilizer production. This chapter discusses the principles and rationale for algae-based wastewater treatment coupled with biodegradation of wastewater and renewable energy production. Several biomass technologies for energy production are proposed, which improve the economic feasibility of algal biofuel production. The integration of membrane bioreactors with algae cultivation is also addressed. A new method with separated trophic conditions, enhanced algal nitrification process (EANP), is introduced for practical applications. It seems that pretreatment of raw wastewater and separated culture condition is required to overcome the challenges of scale-up and enhance nitrification rates. Furthermore, synergistic coupling of the microalgae production via advanced wastewater treatment is highlighted in the context of sustainability benefits.
Jae-Hoon Hwang, Anwar Sadmani, Seung-Jin Lee, Keug-Tae Kim, Woo Hyoung Lee

Chapter 13. Phycoremediation: An Integrated and Eco-friendly Approach for Wastewater Treatment and Value-Added Product Potential

This book chapter presents a review on the application and challenges of microalgae (phycoremediation) for wastewater treatment. Primarily, the general brief is an investigative focus that compares current technologies in wastewater research around the globe and emphasizes the positive aspects of the phycoremediation approach. Much scientific literature has reported the feasibility and innovative merits of phycoremediation, particularly on the assimilation and accumulation of nutrients from wastewater. We discuss the potential of the technology, based on existing reports such as the advantages and disadvantages of phycoremediation. Subsequently, the biomass application from certain quantities of wastewater will have a benefit in the form of commercial applications. The chapter ends with a discussion of trends and future directions based on the detailed literature review with a focus on ensuring safer and sustainable implementation of phycoremediation.
J. Umamaheswari, D. Saranya, S. Abinandan, Mallavarapu Megharaj, Suresh R. Subashchandrabose, S. Shanthakumar

Chapter 14. Pulp and Paper Mill Wastewater: Ecotoxicological Effects and Bioremediation Approaches for Environmental Safety

Pulp and paper industry is one of the important industrial sectors in India, which consume huge amount of water in the papermaking process. The final wastewater is often characterized by high color, BOD (biochemical oxygen demand), COD (chemical oxygen demand), AOX (adsorbable organic halides), SS (suspended solids), TDS (total dissolved solids), phenolics, heavy metals, and plant components like lignin, tannin, resin acids, and extractives. Finally, these compounds are reached to aquatic and terrestrial ecosystem and causing serious environmental pollution. The generated wastewaters are treated by conventional biological treatment like activated sludge process (ASP) after primary treatment. Biological treatment of paper mill effluent significantly removes BOD, COD, SS, and also COD, but it is insufficient in removal of lignin and chlorophenols due to its low biodegradability and toxicity. During last few decades, several physical and chemical methods have been developed with the aim to use as pre- and posttreatment method. However, application of this technology at large scale is costly. Therefore, bioremediation which involve the use of pollutant-specific microorganism for wastewater treatment has been considered as cost-effective and eco-friendly treatment method. Thus, this chapter provides the updated information on paper processing and wastewater generation and their characteristics and toxicity. Processes based on physicochemical and biological methods for the treatment of pulp and paper mill wastewater have been also discussed.
Izharul Haq, Abhay Raj

Chapter 15. Cadmium as an Environmental Pollutant: Ecotoxicological Effects, Health Hazards, and Bioremediation Approaches for Its Detoxification from Contaminated Sites

Cadmium (Cd) is a toxic heavy metal that enters the environment through various natural and anthropogenic sources and is a potential threat to most organisms including human beings. Cadmium is nondegradable in nature and hence once released to the environment stays in circulation. With progressive industrialization, the amount of this polluting toxic metal is increasing at an alarming rate. Humans get exposed to cadmium by ingestion (drinking or eating) or inhalation (breathing). Ailments such as bone disease, renal damage, and several forms of cancer are attributed to overexposure to cadmium. Bioremediation is an innovative and promising technology for the removal of heavy metals in polluted water and lands and is very attractive in comparison with physicochemical methods because of its lower cost and higher efficiency at low metal concentrations. In microbial remediation, microorganisms can be used at the site of contamination (in situ) or off the contamination site (ex situ) for remediation. Combining both microorganisms and plants is an approach to bioremediation that ensures a possible solution for heavy metal pollution since it includes sustainable remediation technologies to rectify and re-establish the natural condition of soil.
Sushila Saini, Geeta Dhania

Chapter 16. Cyanobacteria: The Eco-Friendly Tool for the Treatment of Industrial Wastewaters

As the earth’s human population has increased, an enormous industrial growth has taken place throughout the world. Industry is the most flagrant abuser of water quality. It discharges polluted water having the pollution strength of at least double the sewage of all municipalities combined. Industrial effluents are the most important sources of toxic contaminants in any environment. Discharge of untreated industrial wastewater into aquatic bodies is posing a serious threat to the water resources. It should be treated before discharge into the natural water bodies. Recently, there has been increasing interest in cyanobacteria for the treatment of industrial wastewater (phycoremediation) since they possess many advantages over other microorganisms. Cyanobacteria are photoautotrophic in nature and have the ability to fix atmospheric nitrogen enabling them to be productive. In this way cyanobacteria are inexpensive; they can maintain their growth without the addition of nutrients. They are known to inhabit in various aquatic and highly polluted environment and acquired natural resistance against environmental pollutants. Cyanobacteria are efficient in the assimilation of organic matter and have high biodegradation, transformation, and biosorption capability of pollutants present in industrial wastewater. In addition, cyanobacteria have a great potential as a source of biofuels, bio-fertilizers, animal feed, polysaccharide production, etc. which makes them a viable and sustainable approach for the treatment of industrial wastewater and can be improved through genetic engineering technologies. This chapter represents the biodiversity of cyanobacteria and their potential application for the removal of heavy metals, dyes, crude oil, and pesticides from the wastewaters of different industries followed by a critical overview of their utilization, suitability, biomass production, and potential in bioremediation of industrial wastewater.
Sharma Mona, Virendra Kumar, Bansal Deepak, Anubha Kaushik

Chapter 17. Plant-Microbe Interactions for Bioremediation and Phytoremediation of Environmental Pollutants and Agro-ecosystem Development

Development in both the industrial and agricultural sectors has resulted in excess production of hazardous substances which is ruining our environment. However several physicochemical technologies are available to treat such substances but require extra setup to deal with eco-friendly manner. Phytoremediation and bioremediation has emerged as a substitute of such technologies which is brought by the interaction among plant and microorganisms. PGPR (plant growth-promoting rhizobacteria) has an important contribution in remediation of environmental pollutants as well as agro-ecosystem development. Along with PGPR, several fungi, endophytes, mycorrhiza, and algae also form association with plants and contribute in sustainable development. Application of genetic engineering has resulted tremendous effect in increasing their efficiency of pollution control and plant growth regulation.
Akash Mishra, Shraddha Priyadarshini Mishra, Anfal Arshi, Ankur Agarwal, Sanjai Kumar Dwivedi

Chapter 18. Molecular Technologies for Assessment of Bioremediation and Characterization of Microbial Communities at Pollutant-Contaminated Sites

Among the various microbial biodegradation techniques, molecular microbiology methods have revolutionized microbial biotechnology, thus leading to rapid and high-throughput methods for culture-independent assessment and exploitation of microbes present in polluted environments. Whether organic or inorganic, pollutants present in contaminated sites can cause an imbalance in the ecosystem by affecting the flora and fauna. The efficiency of naturally occurring microorganisms for field bioremediation could be significantly improved by the microbial molecular biology approach for its comparatively high efficiency and safety. Many techniques, including polymerase chain reaction (PCR), fluorescent in situ hybridization (FISH), denaturing gradient gel electrophoresis (DGGE), ribosomal intergenic spacer analysis (RISA), amplified ribosomal DNA restriction analysis (ARDRA), terminal-restriction fragment length polymorphism (TRFLP), single-strand conformation polymorphism (SSCP), and ribosomal intergenic spacer analysis (RISA) can be selectively employed in microbial flora and ecology research. Recent methods such as genotypic profiling, metagenomics, ultrafast genome pyrosequencing, metatranscriptomics, metaproteomics, and metabolomics have provided exemplary knowledge about microbial communities and their role in the bioremediation of environmental pollutants.
Only 1% of the microbial diversity can be cultured by traditional techniques. Thus, the application of molecular techniques in studying microbial populations in polluted sites without the need for culturing has led to the discovery of novel and previously unrecognized microorganisms. Such complex microbial diversity and dynamics in contaminated soil offer a clear opportunity for bioremediation strategies. These techniques not only prove the existence of microbes in polluted sites but also reveal the undetectable complex relationships among them.
This book chapter presents an overview of the different applications of molecular methods in bioremediation of hydrocarbons and other pollutants in environmental matrices and an outline of recent advances in the applications of such techniques.
Sudhir Kumar Shekhar, Jai Godheja, Dinesh Raj Modi

Chapter 19. Biochar: A Sustainable Tool in Soil Pollutant Bioremediation

Soil is a vital reservoir of living being likely bacteria, fungi, algae, protozoa, etc. They dynamically standardize ecosystem functioning but, due to some imbalance and unstoppable anthropogenic activities, for instance, industrialization, urbanization, and wrong agricultural practices, cause soil pollution, eventually resulting in various environmental health hazards. Although there is no any single factor that is responsible for leading these challenges, many more other activities are involved in a direct and indirect manner to creating environmental pollution. Hence newly developed sustainable, cost-effective, and different feedstock-mediated carbon-rich by-product is a unique and multifunctional sorbent called “biochar” that can play a vital role in bioremediation of several highly hazardous petroleum refinery wastes containing different types of aliphatic, aromatics, other complex hydrocarbons, and heavy metals in contaminated soils due to the longtime recalcitrant nature against microbial degradation. Currently, biochar is used as carrier sorbent for various microorganisms since they stimulate the in situ bioremediation of several hazardous polycyclic aromatic hydrocarbon (PAH) compounds and heavy metals, due to the large surface area and micropores; consequently pollutants are adsorbed on the surface. Biochar may work singly and along with manure compost and remediates many hazardous pollutants from contaminated soils.
Chhatarpal Singh, Shashank Tiwari, Jay Shankar Singh

Chapter 20. Bioremediation of Melanoidins Containing Distillery Waste for Environmental Safety

Distillery waste (DW) is a major threat to the environment for its safe disposal due to their high content of various toxic inorganic and organic compounds. The degradation and detoxification of color-contributing compounds such as caramel, melanoidins, and plant phenolics and their metabolic products are essential prior to disposal of DW into the environment. Distilleries employ different forms of primary and secondary processes for effluent treatment; however, these treatment methods are highly energy intensive and hence quite expensive. Biological methods present an incredible alternate for decolorization and detoxification of DW due to their environmentally friendly, low cost, and publicly acceptable treatment processes. A wide variety of aerobic microorganisms including bacteria, fungi, actinomycetes, and cyanobacteria have the ability to decolorize melanoidins containing DW. But DW containing different types of pollutants are not easily degraded by the single-step treatment process. Up to the present, however, no suitable method for the promising treatment of huge amounts of DW has been developed. The present book chapter aims to provide a comprehensive overview of some of the promising bioremediation and phytoremediation approaches used for the management of DW. Further, the use of two-step sequential approach for the treatment of DW is highlighted. Furthermore, the challenges and future prospects of bioremediation of DW are also discussed.
Vineet Kumar, Ram Chandra

Chapter 21. Progresses in Bioremediation Technologies for Industrial Waste Treatment and Management: Challenges and Future Prospects

Industrial wastewater treatment and management is a major challenge of the twenty-first century and essential to safeguard the environment and public health. Industrial wastewaters are considered as one of the major sources of environmental contamination because these carry a variety of environmental contaminants that may cause serious health hazards in living beings. To protect the environment and public health from the adverse effects of such industrial pollutants, several methods are currently being applied to manage such industrial wastes. These methods include physicochemical techniques, which are not eco-friendly in nature as these use chemicals for environmental cleanup and thus cause secondary pollution and are costly. However, bioremediation technologies are one of the self-driven eco-friendly methods as these rely on the activity of microbes and plants that remove an array of pollutants from polluted wastewaters. This chapter reviews the progresses made in the bioremediation technologies for industrial waste treatment and management with reference to tannery wastewater and focuses on challenges and future directions in the field.
Ram Naresh Bharagava, Gaurav Saxena
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