A REVIEW ON BIOREMEDIATION OF SUGAR MILL EFFLUENT

In recent years, biorefinery approach with a zero-waste concept has gained a lot research impetus to boost the environment and bioeconomy in a sustainable manner. The wastewater from sugar industries contains miscellaneous compounds and need to be treated chemically or biologically before being discharged into water bodies. Efficient utilization of wastewater produced by sugar industries is a key point to improve its economy. Thus, interest in the sugar industry wastes has grown in both fundamental and applied research fields, over the years. Although, traditional methods being used to process such wastewaters are effective yet are tedious, laborious and time intensive. Considering the diverse nature of wastewaters from various sugar-manufacturing processes, the development of robust, cost-competitive, sustainable and clean technologies has become a challenging task. Under the recent scenario of cleaner production and consumption, the biorefinery and/or close-loop concept, though using different technologies and multi-step processes, namely, bio-reduction, bio-accumulation or biosorption using a variety of microbial strains, has stepped-up as the method of choice for a sustainable exploitation of a wide range of organic waste matter along with the production of high-value products of industrial interests. This review comprehensively describes the use of various microbial strains employed for eliminating the environmental pollutants from sugar industry wastewater. Moreover, the main research gaps are also critically discussed along with the prospects for the efficient purification of sugar industry wastewaters with the concomitant production of high-value products using a biorefinery approach. In this review, we emphasized that the biotransformation/biopurification of sugar industry waste into an array of value-added compounds such as succinic acid, L-arabinose, solvents, and xylitol is a need of hour and is futuristic approach toward achieving cleaner production and consumption.

The development and diffusion of clean technologies has an important role to play in preventing pollution. Government must address the issue of how firms can be given the necessary incentive to develop environmentally sound production techniques and products. This paper focus on how subsidies can — under certain restrictive conditions — stimulate innovation. Subsidization is usually assumed to involve unit subsidies for pollution reduction. Unit subsidies have little to do with the subsidy schemes in actual use. Our focus is on subsidy schemes specifically designed to promote the development of clean technologies through the use of grants/financial aid. Based on data from the development projects initiated through The Danish Clean Technology Programme we analyze how environmental innovations take place when the polluters, their suppliers and consultants are actively engaged in the development processes. The main merit of subsidy schemes like the Danish one is its direct focus on the innovation processes and the active incorporation of the network of firms surrounding the polluters. Our findings lead us to conclude that when it comes to subsidization, the role of government should be redefined. Government can act as a “matchmaker” by providing firms with informative incentives and necessary contacts for finding more efficient technological solutions to specific environmental problems.

Bioremediation is considered as one of the safer, cleaner, cost effective and environmental friendly technology for decontaminating sites which are contaminated with wide range of pollutants. The term bioremediation has been introduced to describe the process of using biological agent to remove toxic waste from environment. Bioremediation is the most effective management tool to manage the polluted environment and recover contaminated soil. The process of bioremediation uses various agents such as bacteria, fungi, algae and higher plants as major tools in treating heavy metals present in the environment. Bioremediation, both In situ and ex-situ have also enjoyed strong scientific growth, in part due to the increased use of natural attenuation, since most natural attenuation is due to biodegradation. Bioremediation and natural attention are also seen as a solution for emerging contaminant problems. Microbes are very helpful to remediate the contaminated environment.

Natural attenuation involves the use of the natural processes with the soil and groundwater to remediate contamination by physical, chemical, and biological processes to reduce the risk to human health and the environment. Although the use of natural attenuation as a treatment process is increasing for remediation of contaminated groundwater, much less research has focused on contaminated soils and sediments. Industrial effluents, agricultural runoff, and sewage discharges are major sources of contaminants for the sediments. In addition, benthic organisms can transport contaminants through bioturbation and there is considerable variability at sites. Organic materials, a particularly important component of the sediments, can sequester the contaminants. Sediment-water partitioning controls the release of the contaminants into pore water and benthic organisms. Fate and transport mechanisms for both organic and inorganic contaminants within the sediments need to be understood to establish protocols for the monitoring and use of natural attenuation.

Natural attenuation involves the use of the natural processes with the soil and groundwater to remediate contamination by physical, chemical, and biological processes to reduce the risk to human health and the environment. Although the use of natural attenuation as a treatment process is increasing for remediation of contaminated groundwater, much less research has focused on contaminated soils and sediments. Industrial effluents, agricultural runoff, and sewage discharges are major sources of contaminants for the sediments. In addition, benthic organisms can transport contaminants through bioturbation and there is considerable variability at sites. Organic materials, a particularly important component of the sediments, can sequester the contaminants. Sediment-water partitioning controls the release of the contaminants into pore water and benthic organisms. Fate and transport mechanisms for both organic and inorganic contaminants within the sediments need to be understood to establish protocols for the monitoring and use of natural attenuation.

Monitored natural attenuation has become accepted as an appropriate “technology” for treating petroleum hydrocarbon-contaminated groundwater. Commonly, the monoaromatic compounds benzene, toluene, ethylbenzene, and xylenes (BTEX) and oxygenated additives, e.g., methyl tert-butyl ether (MTBE), are the major constituents of regulatory importance. Although a variety of naturally occurring attenuation mechanisms may reduce BTEX and MTBE concentrations, intrinsic biodegradation is the primary destructive mechanism. Attenuation by anaerobic biodegradation is important for BTEX compounds because of the relative abundance of anaerobic electron acceptors as compared with dissolved oxygen. Field studies indicate that MTBE is also biodegradable in shallow aquifers, but at a slower rate relative to BTEX compounds; thus, dispersion and dilution may also be important MTBE attenuation mechanisms. To demonstrate that natural attenuation is occurring, it is critical to document the proposed natural attenuation processes in the field. These processes often cause measurable “footprints.” At a large number of petroleum-hydrocarbon release sites, natural attenuation processes have been observed and documented and found to control the extent of migration of BTEX contaminants. Although the presence of MTBE may compromise the use of natural attenuation at some sites due to the greater mobility and persistence of MTBE compared to BTEX, some data indicate that MTBE plumes do eventually stabilize.

Natural attenuation is currently being applied as a remedial technology at many petroleum hydrocarbon and chlorinated compound contaminated sites. Although information on the use of natural attenuation at these sites is abundant, information on sites contaminated with polycyclic aromatic hydrocarbons (PAH) is limited. An assessment report by the National Research Council on natural attenuation indicates that the current understanding of the fate and transport of PAH compounds at contaminated sites is “moderate” and the likelihood of success in the application of natural attenuation at these sites is expected to be “low,” given the current level of understanding. The purpose of this paper is to review documented work on natural attenuation of PAH-contaminated sites and summarize information to improve our level of understanding and address important issues for the implementation of natural attenuation at these sites. The main processes affecting the attenuation of PAH compounds are sorption and biodegradation. The relative contribution of each of the two attenuation processes is unclear. The few studies available tend to focus on the degradation of low molecular weight PAHs such as naphthalene, acenaphthylene, and phenanthrene. The estimated first-order decay rates of naphthalene, acenaphthylene, and phenanthrene from the various studies were 0.00057–0.0063 day−1, 0.00027 day−1, and 0.000027 to 0.063 day−1, respectively. Some of the issues that need further investigation include: (1) an understanding of the solubility and dissolution of PAH NAPLs; (2) the interactions and effects of the more soluble low molecular weight PAHs on the sparingly soluble high molecular weight PAHs; and (3) the utilization of electron acceptors other than oxygen during microbial degradation of PAHs under complex mixture conditions. Overall, the natural attenuation of low molecular weight PAHs appears to be promising for the sites investigated.

Natural attenuation processes affect the fate and transport of organic compounds in many hydrologic systems. Over the last several years, regulatory agencies and environmental professionals have come to recognize the importance of these natural processes in effecting contaminant attenuation. When they are shown to be protective of human health and the environment, and when a well‐designed monitoring program is in place to document the efficiency of these processes, they can be a valuable component of site remediation strategies.

This special issue on clean energy and environmental technologies aims at providing a forum for researchers who are working on relevant areas to exchange ideas driving innovation and report their latest research outcomes in developing clean energy and environmental technologies. A few years ago, Nobel Laureate Richard E. Smalley outlined Humanity’s Top Ten Problems for the next fifty years, in a talk given for the Enterprise Forum at Massachusetts Institute of Technology (MIT). Energy was listed as the first of the top ten problems and the environment as the fourth. Actually energy is the most basic requirement for economic development and people’s livelihoods while this requirement is constantly increasing, particularly in economically rapidly developing countries like China. Supply of energy still mainly relies on fossil fuels such as coal, petroleum, and natural gas around the world. However reserves for fossil fuels are limited and producing energy from these fossil fuels with existing technologies has caused serious environmental problems, e.g., increasing greenhouse gases emission which exacerbates global warming. Resolutions to these global problems lie in the innovative technologies to produce energy in a clean and environmentally friendly manner. Both developing renewable energy and using energy more efficiently are major components of clean energy and environmental technologies. Development of clean energy and environmental technologies has been thought of as two of the most active research fields today. This special issue includes 12 papers consisting of research and review articles selected from different research institutions in Australia, China and Indonesia. They contain a wide range of the hottest research topics in clean energy and environmental technologies, including development of the innovative catalysts used for clean energy and environmental processes, studies on hydrogen production and storage, CO2 capture and syngas clean technology as well as other research in energy efficiency, coal seam gas recovery and environmental economics. These research and/or review articles, which although do not cover the full scope of studies in energy and environment due to page limitations , can still provide readers with brief track references to facilitate the development of new clean energy and environmental technologies. This special issue was organized as per instructions of the Editors Dr. Fei Yuan, Prof. Yaodong Huang, and Prof. Yanni Li. We have received invaluable help from colleagues working with or having worked with clean energy and environmental research, especially Prof. Edward White, Prof. Duong Do, Dr. Greg Birkett and Dr. Fu-Yang Wang in School of Chemical Engineering, the University of Queensland. They provided careful peer-reviews on the selected papers with many useful comments and suggestions for authors to enhance the quality of the papers. It would be impossible to publish this special issue without the help of these peer-reviewers. Finally, as the Guest Editor, I would like to thank all the people—all the authors and co-authors and reviewers for their contributions to this special issue, and editors of the Frontiers of Chemical Science and Engineering for their scientific input and consistent support.

Sugar industry pollutes air, water and soil that different types of advanced pollution control technologies were used to reduce the pollution levels to permissible limits. But still Sugar industry manages to recycle and reuse its by-products based on the “concept of industrial ecology” on its own production premises in a holistic positive environmental management approach. Due to the production totally based on agricultural products using “biomass”, which is organic from the starting till the end of the product, there is a total life cycle assessment (LCA). Recycling of products like water recycling in a closed loop water saving system, molasses reuse, Co-generation (energy conservation), variable frequency drives (VFD), cane cutting, bagasse, press muds, composting using sludge are few methods followed in this unit. Sugar industry cost variables Economic and environmental variables, older (Conventional) and newer (Cleaner) technology and their negative and positive advantages were compared. Variables like capital cost, variable cost, viability period of the equipment, depreciation cost, buy back cost, benefit cost and environmental benefits like energy in (kWh) per year, water in liters per year and other recycling process like “Add-on” and “Process change” technologies are taken in consideration. The main objective is to focus on the cost aspects between the two technologies, conventional and cleaner technology in pollution control. This was carried out by comparing cost benefit analysis and Return on Investment (ROI) for the old and clean technologies. The other parameter compared was cost benefit liter per year using cleaner recycling leading to environmental advantage. There are nine technologies used in this industry that has been analyzed.

This research focuses on analyzing the cooperation between the United States and Australia within the framework of the Indo-Pacific Economic Framework (IPEF), particularly in realizing the clean economy pillar. Grounded in the Theory of Neoliberalism and the Concept of International Cooperation, this study aims to further examine the dynamics of IPEF collaboration, especially in the context of bilateral relations between the United States and Australia, to enhance economic growth through commodity exports and the development of low-carbon clean technologies to ensure environmental security and sustainability in the face of industrialization. In implementing the clean economy pillar of IPEF, the involvement of Non-State Actors in the energy sector, particularly Chevron Corporation, plays a crucial role in supporting and maximizing Australia’s agenda to become an energy superpower while maintaining environmental safety as a priority. Chevron’s presence is significant in the IPEF cooperation between the United States and Australia due to its substantial impact on the domestic economy and its tangible commitment to carbon emission reduction. This research reveals the importance of bilateral cooperation, investment, and the development of clean technologies in achieving the clean economy pillar of the IPEF.

The collective processes that constitute the broadly used term "natural attenuation," as it relates to subsurface remediation of contaminants, refer to the physical, chemical, and biological interactions that, without human intervention, reduce or contain contaminants in the subsurface environment. Knowledge of these processes has been used successfully to control water quality in surface water. However, the understanding of the impact of the same processes in the subsurface environment has improved fundamentally and dramatically over the course of the last three decades. It is now known that chemicals are capable of moving deep into the subsoil and sediments and are subject to a wide variety of complex chemical reactions, water/solid interactions, and microbial degradation. This chapter discusses the evolution in our understanding of these processes, how they relate to current philosophies concerning subsurface contaminant cleanup standards, and the issues pertaining to public acceptance of natural attenuation as an important component of remediation strategy.

Among the alternatives considered for the remediation of soil and ground water at hazardous wastes sites are the use of natural processes to reduce or remove the contaminants of concern, Under favorable conditions, the use of natural attenuation can result in significant cost savings and compensate for uncertainties encountered in complex subsurface settings. In order to demonstrate that natural processes are effective in reaching established goals it is necessary to determine that transformation processes are taking place at a rate which is protective of human health and the environment, and that these processes will continue for an acceptable period of time.While chemical transformation, dispersion, dilution, sorption, and volatilization are discussed, aerobic and anaerobic degradation comprise the major processes for the reduction of contaminant mass in the subsurface. In discussing the mechanisms of natural attenuation, chlorinated aliphatics and petroleum hydrocarbons are used as examples because of their significant impact on subsurface contamination and the effect of their physiochemical properties on attenuation processes.

Monitored natural attenuation (MNA) of contaminated soils: State of the art in Europe—A critical evaluation

Purpose This study aims to investigate the contribution of Islamic green financing (IGF) for renewable energy in the Gulf Cooperation Council nations from 2019–2023, with the objective of promoting a transition to a low-carbon economy. Design/methodology/approach The study uses a fixed effects model to examine individual effects and time heterogeneity. Findings The Natural Resource Based-View addresses strategic questions regarding the resources, capabilities and firms most suited to build dynamic capabilities for clean (renewable) technologies. Using a fixed effect approach, IGF enhances solar-based renewable technologies through energy efficiency and climate policy. Practical implications The dynamic capabilities view is used to conceptualize green orientation (reflected in national climate policy), meanwhile, the Natural Resource Based-View in this study is used to conceptualize managerial environmental commitment (reflected in IGF), product stewardship (reflected in energy use) and eco-innovation (reflected in renewable energy) within a unified framework. Social implications This study advocates for energy justice in climate policy and energy structure reformation. Energy justice (inherent in Islamic financing) can provide powerful conceptualization and analysis tools for policymaking to achieve a fair and balanced energy system, ensuring an equal distribution of benefits. Additionally, with a risk-sharing mechanism in joint ventures, IGF reforms the energy competition structure by enabling new entrepreneurs to compete with established enterprises in energy technologies, resulting in more effective and efficient products, services and prices. Originality/value This study fills the important gaps of product stewardship and sustainable development strategies in Natural Resource Based-View studies and expands the Natural Resource Based-View body of knowledge by systematically linking financial resources and sustainable development in clean technology while most empirical studies solely focus on pollution prevention and firm profitability. Therefore, this paper explores the understudied impact of IGF on renewable energy via national climate policy and energy efficiency.