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In this work, the industrial case study of effluent drying with a direct and hybrid heat recovery configuration is investigated for the purpose of improving heat recovery potential and understanding the influence of various design parameters on the performance indicators in the spray drying process. Initially, data collection and performance analysis of industrial spray dryer of effluent management is performed. Then, the effect of design variables such as recirculation ratios, mass flow rate of dry hot air, water vapor, temperature of the mixing chamber, and heat input on performance parameters (thermal efficiency, energy savings, and the sustainability index) are evaluated for several configurations of the spray drying unit used in effluent management. As an outcome, substantial improvement in energy efficiency (83%) and energy-saving (26%) was achieved for a spray drying system with a 70% recirculation ratio of exhaust air for a hybrid heat recovery configuration, which is approximately 2.5% higher than the direct heat recovery configuration and it is significantly higher than that without an energy recovery system. In addition, a significant reduction in the blower power and heat input is noted in the direct and hybrid heat recovery system. The sustainability index is higher for the hybrid heat recovery configuration, indicating it being the most environment friendly configuration. The absolute humidity in the exhaust air is kept constant during entire investigation for uniformity in analysis. [ABSTRACT FROM AUTHOR]

Microbial biodiversity includes biotic and abiotic components that support all life forms by adapting to environmental conditions. Climate change, pollution, human activity, and natural calamities affect microbial biodiversity. Microbes have diverse growth conditions, physiology, and metabolism. Bacteria use signaling systems such as quorum sensing (QS) to regulate cellular interactions via small chemical signaling molecules which also help with adaptation under undesirable survival conditions. Proteobacteria use acyl-homoserine lactone (AHL) molecules as autoinducers to sense population density and modulate gene expression. The LuxI-type enzymes synthesize AHL molecules, while the LuxR-type proteins (AHL transcriptional regulators) bind to AHLs to regulate QS-dependent gene expression. Diverse AHLs have been identified, and the diversity extends to AHL synthases and AHL receptors. This review comprehensively explains the molecular diversity of AHL signaling components of Pseudomonas aeruginosa, Chromobacterium violaceum, Agrobacterium tumefaciens, and Escherichia coli. The regulatory mechanism of AHL signaling is also highlighted in this review, which adds to the current understanding of AHL signaling in Gram-negative bacteria. We summarize molecular diversity among well-studied QS systems and recent advances in the role of QS proteins in bacterial cellular signaling pathways. This review describes AHL-dependent QS details in bacteria that can be employed to understand their features, improve environmental adaptation, and develop broad biomolecule-based biotechnological applications. [ABSTRACT FROM AUTHOR]

Superheated steam is a vital drying media due to inherently passive, nonpoisonous, no fire risk, antioxidant, and compatible with food products with superb thermophysical properties than hot air. Moreover, it will improve energy efficiency by energy-saving due to reusing the energy from exhausted steam, mainly by recirculation, and the use of partial exhaust of excess steam for other operations reduces the additional energy requirement. Additionally, the specific heat at constant pressure for superheated steam is nearly double that of the hot air, reducing the quantity required for drying. In general, superheated steam as a drying medium instead of hot air has significant potential. In this study, past, present, and prospects of the superheated steam drying (SSD) are critically analyzed and are presented systematically, such as classification, working, and recent developments. This study also focused on various areas such as analytical modeling, experimental work, and pilot-test of SSD with covering energy recovery and energy efficiency. Out of different drying systems, Fluidized bed dryers, Vacuum dryers, Rotary dryers, Flash dryers, Impingement dryers, and Spray dryers applicable for SSD are discussed in details as the current stage of development and probable potential. The SSD is having bright future for diverse applications including vegetable drying and fruit processing, chemical process industries, wood drying, chemicals, dyestuff and pigments recovery, effluent drying, etc. [ABSTRACT FROM AUTHOR]

This paper presents the optimal step least mean square algorithm for controlling three-phase distributed static compensator (DSTATCOM). The presented algorithm provides harmonic compensation in addition to reactive power compensation in three-phase connected linear and non-linear loads. In order to provide desired compensation by DSTATCOM system, the proposed control algorithm adaptively estimates an optimal value of a step-size parameter for active and reactive weight calculation. These calculated weights are used for deriving the reference current and triggering pulses for the IGBTs of the voltage source converter. The test result shows that the performance of DSTATCOM system is satisfactory, as the three-phase source current remains balanced and sinusoidal with total harmonic distortion within a 5% level set by an International Standard IEEE 519-1992. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Proposed hybrid heat recovery system for efficient energy utilization of spray dryer. • Proposed new performance indicator to assess sustainability in heat recovery systems. • Developed rigorous mathematical model for direct and hybrid heat recovery systems. • Investigated optimal performance of spray dryer. • Compared proposed energy recovery schemes to find best configuration. Abstract Thermal dewatering using spray dryers is an energy-intensive process, which recently, applied for removal of water from industrial effluents by evaporation. Reduction of energy consumption is vital to reduce operating cost in addition to sustainable development. In this paper, the modern integrated energy savings scheme is proposed in four parts. (i) An advanced energy saving configuration named as a hybrid heat recovery system for a spray dryer, (ii) Developed rigorous but simple mathematical model for direct and hybrid heat recovery system, (iii) A generalized performance indicator for investigation of environmental impact on energy recovery called as 'Sustainability Index' is proposed for thermal systems and demonstrated for spray dryer, and finally (iv) The proposed methods are explained with the help of an illustrative example taken from the literature. Up to 80% recirculation ratio, performance enhancement, and Sustainability Index are significantly higher for the hybrid heat recovery system than the direct heat recovery system, while for higher than 80% recirculation ratio, both are approaching towards nearly same value. Furthermore, with increasing recirculation ratio, moisture recirculation into the drying chamber also increases, which reduces the requirement of the mass flow rate of dry hot air due to the higher heat capacity of recirculated moisture. A reduction in hot air requirement reduces the high-grade blower power in addition to net heat supplied. Dryer efficiency and sustainability index, both show a strong dependency on the amount of heat recovery for spray dryer. [ABSTRACT FROM AUTHOR]

This article presents the three-phase enhanced phase-locked loop control of a three-phase distribution static compensator under linear and non-linear loads for improving power quality. The proposed control algorithm adaptively estimates the active and reactive fundamental components of load currents for estimation of reference supply currents, which minimizes the supply current total harmonic distortion within the limits of IEEE Standard 519. The simulation model of the proposed system is developed by using the MATLAB/Sim Power Systems toolbox (The MathWorks, Natick, Massachusetts, USA), and its results are found acceptable to diminish harmonics distortions, reactive power compensation, and load balancing in both power factor correction and zero voltage regulation modes. [ABSTRACT FROM AUTHOR]

In this study, an interior point optimisation‐based control algorithm is proposed for three‐phase distribution static compensator under distorted AC mains. The proposed algorithm is used to determine the optimal value of load fundamental conductance and susceptance, which minimises the supply apparent power, subjected to predefined total harmonic distortion (THD) and individual harmonic distortion limit of supply current as per international guidelines. Unlike the other optimisation techniques, this technique is based on matrices calculations, which makes it effective during load dynamics. The proposed control scheme is implemented for mitigating multiple power quality issues such as load balancing, reactive power compensation and harmonics suppression in power factor correction and zero‐voltage regulation modes under linear and non‐linear loads. [ABSTRACT FROM AUTHOR]

• Biowastes as a resource for producing bioplastics such as polyhydroxyalkanoates (PHAs). • Potential PHAs as nontoxic implants, biocontrol, tissue repair, and drug delivery agents. • Strategy for improving soil, delivering biocides, and mulching through PHAs. • Plastic waste management through sustainable technologies. Plastics are an integral part of most of the daily requirements. Indiscriminate usage and disposal have led to the accumulation of massive quantities of waste. Their non-biodegradable nature makes it increasingly difficult to manage and dispose them. To counter this impending disaster, biodegradable polymers, especially polyhydroxy-alkanoates (PHAs), have been envisaged as potential alternatives. Owing to their unique physicochemical characteristics, PHAs are gaining importance for versatile applications in the agricultural and medical sectors. Applications in the medical sector are more promising because of their commercial viability and sustainability. Despite such potential, their production and commercialization are significant challenges. The major limitations are their poor mechanical strength, production in small quantities, costly feed, and lack of facilities for industrial production. This article provides an overview of the contemporary progress in the field, to attract researchers and stakeholders to further exploit these renewable resources to produce biodegradable plastics on a commercial scale. [ABSTRACT FROM AUTHOR]

• Biowastes as a resource for producing bioplastics such as polyhydroxyalkanoates (PHAs). • Potential PHAs as nontoxic implants, biocontrol, tissue repair, and drug delivery agents. • Strategy for improving soil, delivering biocides, and mulching through PHAs. • Plastic waste management through sustainable technologies. Plastics are an integral part of most of the daily requirements. Indiscriminate usage and disposal have led to the accumulation of massive quantities of waste. Their non-biodegradable nature makes it increasingly difficult to manage and dispose them. To counter this impending disaster, biodegradable polymers, especially polyhydroxy-alkanoates (PHAs), have been envisaged as potential alternatives. Owing to their unique physicochemical characteristics, PHAs are gaining importance for versatile applications in the agricultural and medical sectors. Applications in the medical sector are more promising because of their commercial viability and sustainability. Despite such potential, their production and commercialization are significant challenges. The major limitations are their poor mechanical strength, production in small quantities, costly feed, and lack of facilities for industrial production. This article provides an overview of the contemporary progress in the field, to attract researchers and stakeholders to further exploit these renewable resources to produce biodegradable plastics on a commercial scale. [ABSTRACT FROM AUTHOR]

• Development of pinch analysis strategy for a new domain of an evaporative system. • Process integration of spray dryer with indirect heat recovery, a new approach. • Process integration of spray dryer with a hybrid heat recovery system for high efficiency. • Energy analysis and management of an integrated system for maximum performance. • Techno-economic analysis of driving potential on the energy recovery configurations. Energy recovery is essential as it reduces fuel cost and pollution due to emission of flue gases. The energy recovery potential can be easily determined by pinch analysis, where individual fluid streams obey mass balance. However, in this paper, pinch analysis based methodology is proposed for energy targeting of evaporative systems such as dryers where the mass balance of individual streams is not possible due to loss of identity of one of the streams (feed) because of evaporation of water content and separation of the solid part. Initially, a spray dryer with a counterflow arrangement is selected to demonstrate the applicability of pinch analysis for targeting of energy requirement considered as the base case. Additionally, three different heat recovery configurations integrated with spray dryers are explored by pinch analysis for energy targeting as: (i) direct heat recovery, (ii) indirect heat recovery, and (iii) hybrid heat recovery systems. Further heat recovery potentials and their effect on the performance of the drying process are evaluated appropriately for different cases based on exhaust gas temperatures. The pinch analysis shows that with decreasing a mass flow rate of supply gases/air, the exhaust losses are also reducing for spray dryer integrated with all configuration of the heat recovery system. For spray dryer with indirect heat recovery configuration, energy-saving potential with and without exhaust gas/air temperature constraint is achieved as 57 and 68%, respectively, for a given illustrative example. Among all configurations, a hybrid heat recovery system with 80% recirculation is having the highest thermal energy saving potential (74%) compared to the base case. Moreover, the reduction in the driving potential of spray dryers for direct and hybrid heat recovery configurations is appropriately analyzed for new as well as retrofitted drying systems. It is observed that the effect of driving potential is insignificant for a lower recirculation ratio. Further, techno-economic analysis reveals that there are substantial energy savings even after considering the driving potential suitably in new and retrofitted spray dryers with heat recovery systems. [ABSTRACT FROM AUTHOR]

• Green and sustainable technologies to circumvent waste management. • Microbial potential to metabolize biowastes into bioactive compounds. • Integrated strategy for recovery of value-adding products. • Self-sustaining circular bioeconomy with complete degradation. Biological wastes generated from food and fruit processing industries, municipal markets, and water treatment facilities are a major cause of concern for Health Departments and Environmentalists around the world. Conventional means of managing these wastes such as transportation, treatment, and disposal, are proving uneconomical. The need is to develop green and sustainable technologies to circumvent this ever-growing and persistent problem. In this article, the potential of diverse microbes to metabolize complex organic rich biowastes into a variety of bioactive compounds with diverse biotechnological applications have been presented. An integrated strategy has been proposed that can be commercially exploited for the recovery of value-adding products ranging from bioactive compounds, chemical building blocks, energy rich chemicals, biopolymers and materials, which results in a self-sustaining circular bioeconomy with nearly zero waste generation and complete degradation. [ABSTRACT FROM AUTHOR]

The microbial biotransformation using low-cost feedstock to produce biopolymers (degradable), an alternative to petrochemical-based synthesis plastics (non-degradable), can be a beneficial approach towards sustainable development. In this study, the dairy industry processes waste (whey) is used in polyhydroxyalkanoate (PHA) copolymer production. Initial screening suggested that Ralstonia eutropha produced higher PHA as compared to Bacillus megaterium. A central composite rotatable design-based optimization using two process variables (amino acid and tween-80) concentration remarkably influenced PHA co-polymer production under physiological conditions of pH (7), temperature (37 °C), and agitation rate of 150 rpm. High polyhydroxybutyrate (PHB) mass fraction yield of 69.3% was observed as compared to predicted yield of 62.8% from deproteinized whey as feed. The combination of tryptophan (50 mg L−1) and tween-80 (3 mL−1) enhanced R. eutropha mass gain to 6.80 g L−1 with PHB contents of 4.71 g L−1. Further, characterization of PHA and its copolymers was done by ESI–MS, FTIR, and TEM. On upscaling up to 3.0 L, the PHA contents and yields were noted as quite similar by R. eutropha. This study demonstrates that dairy waste processing waste can be potentially utilized as inexpensive feed for producing high content of biopolymers to develop a sustainable system of waste management. [ABSTRACT FROM AUTHOR]

Vinca alkaloids including vincristine, vinblastine, vindesine, and vinflunine are chemotherapeutic compounds commonly used to treat various cancers. Vinca alkaloids are one of the first microtubule-targeting agents to be produced and certified for the treatment of hematological and lymphatic neoplasms. Microtubule targeting agents like vincristine and vinblastine work by disrupting microtubule dynamics, causing mitotic arrest and cell death. The key issues facing vinca alkaloids applications include establishing an environment-friendly production technique based on microorganisms, as well as increasing bioavailability without causing harm to patient's health. The low yield of these vinca alkaloids from the plant and the difficulty of meeting their huge colossal demand around the globe prompted researchers to create a variety of approaches. Endophytes could thus be selected to produce beneficial secondary metabolites required for the biosynthesis of vinca alkaloids. This review covers the significant aspects of these vital drugs, from their discovery to the present day, in a concise manner. In addition, we emphasize the major hurdles that must be overcome in the coming years to improve vinca alkaloid's effectiveness. [ABSTRACT FROM AUTHOR]

Vinca alkaloids including vincristine, vinblastine, vindesine, and vinflunine are chemotherapeutic compounds commonly used to treat various cancers. Vinca alkaloids are one of the first microtubule-targeting agents to be produced and certified for the treatment of hematological and lymphatic neoplasms. Microtubule targeting agents like vincristine and vinblastine work by disrupting microtubule dynamics, causing mitotic arrest and cell death. The key issues facing vinca alkaloids applications include establishing an environment-friendly production technique based on microorganisms, as well as increasing bioavailability without causing harm to patient's health. The low yield of these vinca alkaloids from the plant and the difficulty of meeting their huge colossal demand around the globe prompted researchers to create a variety of approaches. Endophytes could thus be selected to produce beneficial secondary metabolites required for the biosynthesis of vinca alkaloids. This review covers the significant aspects of these vital drugs, from their discovery to the present day, in a concise manner. In addition, we emphasize the major hurdles that must be overcome in the coming years to improve vinca alkaloid's effectiveness. [ABSTRACT FROM AUTHOR]

Combustion is an essential process for humanity, but it has created turbulence in society due to the pollutant emissions from the partial completion of its process and its byproducts. The regular population is unaware of the repercussions being faced in terms of health deterioration, product quality degradation, biodiversity loss, and environmental harm. Although strategic planning against the effects is being applied sideways by the authorities to the local population and industrial facilities, the awareness in the local population is still minimal. The indicators for bioremediation being required, observed through increased sales of pharmaceutical medicines and supplements, air filters, and new techniques, include smog, elevation in respiratory disease, health immune system deterioration, decreasing life span, increasing mortality rate, and degradation in the food and water quality. This article gives a brief overview of the problems being faced due to uncontrolled combustion activities, the sources of pollutants, their creation, emission, and dispersal process, along with the mitigation techniques developed to overcome the after-effects on human health and environment. [ABSTRACT FROM AUTHOR]

Thirty five bacterial isolates from diverse environmental sources such as contaminated food, nitrogen rich soil, activated sludges from pesticide and oil refineries effluent treatment plants were found to belong to Bacillus, Bordetella, Enterobacter, Proteus, and Pseudomonas sp. on the basis of 16S rRNA gene sequence analysis. Under dark fermentative conditions, maximum hydrogen (H2) yields (mol/mol of glucose added) were recorded to be 0.68 with Enterobacter aerogenes EGU16 followed by 0.63 with Bacillus cereus EGU43 and Bacillus thuringiensis EGU45. H2 constituted 63–69% of the total biogas evolved. Out of these 35 microbes, 18 isolates had the ability to produce polyhydroxybutyrate (PHB), which varied up to 500mg/l of medium, equivalent to a yield of 66.6%. The highest PHB yield was recorded with B. cereus strain EGU3. Nine strains had high hydrolytic activities (zone of hydrolysis): lipase (34–38mm) –Bacillus sphaericus strains EGU385, EGU399 and EGU542; protease (56–62mm) –Bacillus sp. strains EGU444, EGU447 and EGU445; amylase (23mm) –B. thuringiensis EGU378, marine bacterium strain EGU409 and Pseudomonas sp. strain EGU448. These strains with high hydrolytic activities had relatively low H2 producing abilities in the range of 0.26–0.42mol/mol of glucose added and only B. thuringiensis strain EGU378 had the ability to produce PHB. This is the first report among the non-photosynthetic microbes, where the same organism(s) –B. cereus strain EGU43 and B. thuringiensis strain EGU45, have been shown to produce H2 – 0.63mol/mol of glucose added and PHB – 420–435mg/l medium. [Copyright &y& Elsevier]