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Autoclaved Aerated Concrete (AAC) blocks are recently one of the newly adopted building materials. AAC is a product of fly ash which is mixed with lime, cement, and water and an aerating agent. The AAC is mainly produced as cuboid blocks and prefabricated panels. AAC is a type of concrete that is manufactured to contain lots of closed air voids. AAC blocks are energy efficient, durable, less dense, and lightweight. It is manufactured by adding a foaming additive to concrete in different sizes of molds as per requirement, then wire-cutting these blocks or panels from the resulting ‘cake lump’ and ‘heating them with steam. This process is called as Autoclaving. Porotherm clay bricks are horizontally or vertically perforated clay bricks. they are manufactured in variety of sizes (common size is 400x200x200 mm) from natural clay, coal ash, rice husk, and granite slurry. The term Porotherm is used for this type of brick due to its desired thermal insulation characteristics. The perforation of the clay brick provides an exception walling system which facilitates thermal insulation resulting in cooler interiors in hot seasons and warm interior conditions in cold seasons. The Porotherm clay bricks are easy to use, economical, environmentally friendly, and it can be used for the construction of both non-load bearing walls and load bearing walls. The Porotherm bricks are low weight, durable, strong, and possess a satisfactory fire resistance. It can be used with dry mortar which eliminate the need for curing time. Various researchers throughout the world carried out numerous works to investigate and study the behaviour of AAC block and Porotherm brick. Those works were discussed in the review of literature. Different test were conducted in both blocks and its strength are noted. In this project, AAC block made of quartz sand (SiO2 with impurities), calcined calcium sulfate (or plaster of paris), lime (CaO), cement, water and aluminum powder. In this regular practices, cement (26%), fly ash (25%), lime (38%), gypsum (2%), Aluminium powder (9%). In this project cement reduced to 20% , and fly ash increased to 30%. Various strength test can be performed and it can be compared with AAC block and Porotherm brick

Hydrogen is a renewable gas, efficient to produce energy that makes it a suitable alternative and effective solution for a carbon-free environment. Unlike other fossil fuels, combustion of hydrogen does not produce toxic compounds, such as greenhouse gases, carbon monoxide, hydrocarbons, etc., resulting in less environmental pollution. Agro-industrial residues contain several lignocelluloses that favor the growth of microorganisms to produce valuable products such as hydrogen. Of the diverse techniques in hydrogen production, bioconversion proves to be an efficient method in permuting agro-industrial residues into hydrogen. This review provides detailed information on the bioconversion processes and factors involved in hydrogen production from agro-industrial residues including different fermentation processes such as dark fermentation and photo-fermentation, and fuel cell systems such as microbial electrolysis cell and microbial fuel cell. Different pretreatment techniques to enhance the availability of lignocellulose for hydrogen production have been elaborated in this review. Various factors including pH, temperature and nutrient composition of feed, affecting the production efficiency and purity of the products during fermentation have been discussed.

Freshwater has been incessantly polluted by various activities such as rapid industrialization, fast growth of population and agricultural activities. Water pollution is considered as one the major threatens to human health and aquatic bodies which causes various severe harmful diseases including gastrointestinal disorders, asthma, cancer, etc. The polluted wastewater could be treated by different conventional and advanced methodologies. Amongst them, adsorption is the most utilized low cost, efficient technique to treat and remove the harmful pollutants from the wastewater. The efficiency of adsorption mainly depends on the surface properties such as functional group availability and surface area of the adsorbents used. Since various waste-based carbon derivatives are utilized as adsorbents for harmful pollutants removal; nanomaterials are employed as effective adsorbents in recent times due to its excellent surface properties. This review presents an overview of the different types of nanomaterials such as nano-particles, nanotubes, nano-sheets, nano-rods, nano-spheres, quantum dots, etc. which have been synthesized by different chemical and green synthesis methodologies using plants, microorganisms, biomolecules and carbon derivatives, metals and metal oxides and polymers. By concentrating on potential research difficulties, this study offers a new viewpoint on fundamental field of nanotechnology for wastewater treatment applications. This review paper critically reviewed the synthesis of nanomaterials more importantly green synthesis and their applications in wastewater treatment to remove the harmful pollutants such as heavy metals, dyes, pesticides, polycyclic aromatic hydrocarbons, etc.

Water pollution and fossil fuels are major issues in the context of climate change. Photocatalysis research is rising to develop green technologies for the remediation of pollutants and for energy production. Photocatalysis converts the light energy as photons into chemical energy using semiconducting materials. Different methods are utilised to synthesise these photocatalytic materials. Metal and coupled metal frameworks are applied for the production of photocatalytic materials. Here we review the synthesis and applications of photocatalysts for environmental decontamination and for production of biodiesel, methanol and hydrogen. Pollutants include dyes, pesticides, herbicides, phenols and antibiotics.

Food safety is a major concern in the context of rising population and decreasing earth resources. Food is often contaminated by bacteria, viruses, fungi and parasites, which induce disease such as hemolytic uremic, irritable bowel and Guillain–Barre syndromes. Detection of pathogenic microbes is therefore essential for food safety. Detection methods include biological methods, biosensors and methods based on spectroscopy, immunology and nucleic acids. Here, we review advanced detection techniques used to analyze toxic substances in food.

Natural and human anthropogenic activities increase the concentration of the toxic pollutant in the water environment; they could cause harmful effects even in their lower concentration. In humans, toxic pollutants damage the structural and functional properties of essential organs including the heart, liver, kidneys, reproductive systems and pancreas. To avoid the toxicity of the pollutant, they should be removed from the water environment. Since various conventional water/wastewater treatment technologies including precipitation, ion exchange, flocculation, filtration, electrodialysis and membrane separation are employed to reduce the concentration of the pollutant, they have various difficulties in implementation, efficiency and ecological perspective. Therefore, several researchers are now focusing on alternative and eco-friendly approach called biosorption to remove toxic contaminants from the water environment. The biosorption innovation is one of the acclaimed systems for water treatment. The noteworthy endeavours have been made throughout the years to grow profoundly particular and effective biosorbent materials that are more effective, abundantly available, and cost-effective. Biosorption is effectively executed by utilizing both living and dead biomasses of bacteria, fungi and algae. Moreover, agro-waste materials are also utilized as biosorbents due to their excellent surface properties, abundant availability and cost-effectiveness. A variety of physical and chemical treatments enhances the biosorption capabilities of biosorbents via modifying their surface properties. In this review, biosorption mechanism, influencing parameters and application of biosorbent materials towards the removal of toxic pollutants are discussed. The future research opportunities for sustainable wastewater treatment were also explained.

Many countries in the world are facing the demand for non-renewable fossil fuels because of overpopulation and economic boom. To reduce environmental pollution and zero carbon emission, the conversion of biomass into biofuels has paid better attention and is considered to be an innovative approach. A diverse raw material has been utilized as feedstock for the production of biofuel, depending on the availability of biomass, cost-effectiveness, and their geographic location. Among the different raw materials, lignocellulosic biomass has fascinated many researchers around the world. The current review discovers the potential application of lignocellulosic biomass for the production of biofuels. Various pretreatment methods have been widely used to increase the hydrolysis rate and accessibility of biomass. This review highlights recent advances in pretreatment methodologies for the enhanced production of biofuels. Detailed descriptions of the mechanism of biomass processing pathway, optimization, and modeling study have been discussed.

This review is intent on the environmental pollution generated from printed circuit boards and the methods employed to retrieve valuable and hazardous metals present in the e-wastes. Printed circuit boards are the key components in the electronic devices and considered as huge e-pollutants in polluting our surroundings and the environment as a whole. Composing of toxic heavy metals, it causes serious health effects to the plants, animals and humans in the environment. A number of chemical, biological and physical approaches were carried out to recover the precious metals and to remove the hazardous metals from the environment. Chemical leaching is one of the conventional PCBs recycling methods which was carried out by using different organic solvents and chemicals. Need of high cost for execution, generation of secondary wastes in the conventional methods, forces to discover the advanced recycling methods such as hydrometallurgical, bio-metallurgical and bioleaching processes to retrieve the valuable metals generate through e-wastes. Among them, bioleaching process gain extra priority due to its higher efficiency of metal recovery from printed circuit boards. There are different classes of microorganisms have been utilized for precious metal recovery from the PCBs through bioleaching process such as chemolithoautotrophy, heterotrophy and different fungal species including Aspergillus sp. and Penicillium sp. The current status and scope for further studies in printed circuit boards recycling are discussed in this review.

Pollutants is one of the ecological contaminations for the time being days as effect of mechanical improvement in a few nations. Heavy metals and dyes give harmful consequences for human wellbeing and cause a few genuine maladies. A few systems have been utilizing for expelling toxic contaminants from the natural yet these strategies have impediments, for example, cost expense, logistical issues and time consuming, low efficiency. Phytoremediation is the best alternative for tidying up condition, as it is the naturally economical and ecologically practical innovation. Phytoremediation offers proprietors and chiefs of toxic polluted locales is an imaginative and financially effective choice to address headstrong natural contaminants. As it uses plants characteristic capacity to suck the contamination present in the dirt. There are numerous plants having this regular capacity to up take the toxic contaminants and natural contaminations from air, soil and water. There are distinctive subsets of phytoremediation; the most successfully utilized ones are (a) Phytostabilization (b) Rhizodegradation (c) Rhizofiltration (d) Phytodegradation (e) Phytoextraction (f) Phytoaccumulation (g) Phytovolatilization. This review focuses on fortifying innovation system, upgrade the resilience and protection from toxic contaminants, and application impact of phytoremediation.

Graphene has excellent unique thermal, chemical, optical, and mechanical properties such as high thermal conductivity, high chemical stability, optical transmittance, high current density, higher surface area, etc. Due to their outstanding properties, the attention towards graphene-based materials and their derivatives in wastewater treatment has been increased in recent times. Different graphene-based materials such as graphene oxides, graphene quantum dots, graphene nanoplatelets, graphene nanoribbons and other graphene-based nanocomposites are synthesized through chemical vapor deposition, mechanical and electrochemical exfoliation of graphite. In this review, the specifics about the graphenes and their derivatives, the synthesis strategy of graphene-based materials are described. This review critically explained the applications of graphene-based materials in wastewater treatment. Graphene-based materials were utilized as adsorbents, electrodes, and photocatalysts for the efficient removal of toxic pollutants such as heavy metals, dyes, pharmaceutics, antibiotics, phenols, polycyclic aromatic hydrocarbons have been highlighted and discussed. Herein, the potential scope of graphene-based material in the field of wastewater treatment is critically reviewed. In addition, a brief perspective on future research directions and difficulties in the synthesis of graphene-based material are summarized.

Treating the effluents from industries by using biological and agricultural wastes is an emerging field of research. In this study, three different biosorbents are prepared from tamarind seeds such as; raw, sulphuric acid-modified and ultrasonic-assisted surface-modified tamarind seed powder has been utilized to expel the Pb (II) ions from synthetic solution. The surface characteristics of the newly synthesized raw and surface modified agro-waste biomass were studied by FTIR and SEM. An experimental study was carried out to investigate the effect of different parameters on adsorption of Pb(II) ions using raw, sulphuric acid-modified and ultrasonic-assisted surface-modified tamarind seeds. The maximum Pb(II) ions adsorption was found at pH - 6.0, temperature - 303 K, biosorbent dosage - 3.5 g/L and contact time - 60 min for raw tamarind seeds and 30 min for sulphuric acid-modified and ultrasonic-assisted surface-modified tamarind seeds. The adsorption mechanism was described by Langmuir isotherm and pseudo-first order kinetic model. Among the three biosorbents, ultrasonic-assisted surface-modified tamarind seeds show higher adsorption capacity (18.86 mg/g) of Pb(II) ions removal from the synthetic solution. The thermodynamic study declared that the present Pb(II) ions adsorption onto the prepared biosorbents was spontaneous, exothermic and followed physical adsorption process. Results have shown that tamarind seed was found to be the best adsorbent in the expulsion of Pb(II) ions from the wastewater environment.

Industrialization and other human anthropogenic activities cause serious threats to the environment. The toxic pollutants can cause detrimental diseases on diverse living beings in their respective ecosystems. Bioremediation is one of the efficient remediation methods in which the toxic pollutants are removed from the environment by the application of microorganisms or their biologically active products (enzymes). Typically, the microorganisms in the environment produce various enzymes to immobilize and degrade the toxic environmental pollutants by utilizing them as a substrate for their growth and development. Both the bacterial and fungal enzymes can degrade the toxic pollutants present in the environment and convert them into non-toxic forms through their catalytic reaction mechanism. Hydrolases, oxidoreductases, dehalogenases, oxygenases and transferases are the major classes of microbial enzymes responsible for the degradation of most of the toxic pollutants in the environment. Recently, there are different immobilizations and genetic engineering techniques have been developed to enhance enzyme efficiency and diminish the process cost for pollutant removal. This review focused on enzymatic removal of toxic pollutants such as heavy metals, dyes, plastics and pesticides in the environment. Current trends and further expansion for efficient removal of toxic pollutants through enzymatic degradation are also reviewed in detail.

Cassia fistula seeds has been utilized for the abstraction of Pb(II) ions from the aqueous environment. Raw Cassia fistula seeds (RCF) and three different surface modified (physically treated – PMCF and chemically treated – HMCF and SMCF) adsorbent material were taken for investigation. The adsorption properties of these materials and their contact amongst the Pb(II) ion and sorbent materials were characterized by FTIR and SEM analysis. The parameters influencing the adsorption capacity of varied adsorbents were evaluated: maximum solution pH for Pb(II) is 5.0; interactive time is 30 min; dosage is 8.0 g/L for RCF, 4.0 g/L for HMCF, 2.5 g/L for PMCF and 1.0 g/L for SMCF. The modelling study reveals that Freundlich isotherm and Pseudo first order kinetics fits well and the utmost adsorption measurements for the varied adsorbents were found to be 13.22, 28.28, 48.66 and 129.3 mg/g, respectively.

In this present study, a novel and low cost surface improved material was prepared from the farm waste material (Borassus flabellifer male inflorescence) and its surface was enhanced by the sulphuric acid treatment to intensify the Ni(II) ions adsorption. The adsorption individualities such as availability of functional groups, essential elements and the exterior side and structural properties of the material were assessed by the FT-IR, EDX, SEM and XRD investigation. The impact of varied adsorption influencing parameters on Ni(II) ions adsorption was studied and optimized as pH - 6.0, biosorbent dosage - 1.5 g/L, contact time - 60 min and temperature - 303 K via batch adsorption examination. Modeling examinations were carried with varied adsorption isotherm (Langmuir, Freundlich, Fritz-Schlunder and Temkin) and kinetic models (Pseudo-first order, Pseudo-second order and Elovich kinetics). Thermodynamic studies were carried out at varied Ni(II) ions concentrations (25 mg/L – 150 mg/L) and temperatures (303 K–333 K) to explain the nature of Ni(II) ions adsorption on Borassus flabellifer male inflorescence. The prepared material has shown the most suitable Ni(II) ions adsorption results for the Langmuir isotherm (R2 = 0.9808) and Pseudo-first order kinetic models (R2 = 0.9735 for 25 mg/L). Thereby, the modeling study revealed that the prepared material has received the Ni(II) ions adsorption capacity (qm) value of 20.31 mg/g and the Ni(II) ions adsorption was physisorption. Thermodynamic results demonstrated that the Ni(II) ions adsorption was immediate, exothermic and favorable at low temperature.

Nanotechnology is one of the most interesting and fastest growing research fields in environmental research and plays an important role in our day-to-day lives because of its tremendous possibilities, the unique properties of nanomaterials (NMs), huge specific surface areas, microinterface characteristics, remediation capacity, and economic effects. There are different types of products such as nanoparticles, nanotubes, and nanofibers, that have been produced by nanotechnology and their applications have grown in our daily lives. Apart from their use in human areas, they cause several toxic effects to the environment and also plants, animals, and humans. Nanomaterials can enter the plant and human food chain through exposure to NMs present in environmental resources including water, air, and soil which can have adverse effects on the environment and human health due to its chemical composition and irregular shape and size. This chapter highlights the various effects (positive and negative) of NMs on the environment and people.

The present research was investigated to eliminate the cationic dye (malachite green (MG)) from the water environment using coal-associated soil. The adsorbent material was characterized using scanning electron microscopy (SEM) and Fourier Transform Infrared Spectrophotometer (FTIR) analyses. Batch experiments were performed to investigate the different factors which affect the adsorption study. The maximum percentage removal of MG dye was attained as follows: adsorbent dose of 1.0 g/L (0.2 to 1.6 g/L), solution pH of 6.0 (2.0 to 9.0), temperature of 30°C (30 to 60°C), time contact of 60min (10 to 90 min), and dye’s concentration of 25 mg/L (25 to 150 mg/L). The adsorption isotherm was studied with four different isotherm models and results showed that the Freundlich isotherm model gave the best fit than the other nonlinear models to designate the isotherm behaviours with R 2 value of 0.9568, and the maximum adsorption capacity of coal-associated soil for MG dye adsorption is 89.97 mg/g. The evaluation of kinetic studies was performed by using three different kinetic models, where it exposed that pseudofirst order providing the best fit with R 2 value of 0.96 (25 to 150 mg/L). The thermodynamic parameters Gibbs free energy (ΔG°), entropy (ΔS°), and enthalpy (ΔH°) were endorsing that the present adsorption system was exothermic. Thus, the experimental results state that coal-associated soil could be an alternative material for the exclusion of dyes from water.

An assortment of treatment advances is accessible with various levels of achievement to control and limit water contamination. Nonetheless, the deficiencies of a large portion of different conventional strategies are sludge generation, high operational costs, and support costs engaged with the treatment. Among these approaches, adsorption has been displayed as a prudent and viable technique to adsorb harmful contaminants from water bodies. Minimal effort results from agriculture and industrial divisions have been perceived as a reasonable answer for wastewater treatment. Natural polymers are novel materials because of modest, effectively accessible, reproducible sources, hydrophilic and stable biopolymers, protected and without symptoms, and adaptable polymers. Furthermore, they have amazing adsorption properties to expel toxins including heavy metals and dyes from wastewater. In the examination, modifications to improve the sorption capacity by chemical modifications of the sorbents have been explored. Heavy metal ions and dye contaminants have an inclination toward carboxyl and polar groups on the adsorbent. In this manner, the recent research focuses toward the chemical modification of sorbent material as a stage for the consolidation of hydroxyl, amino, and carboxylic groups to improve the adsorptive properties of natural polymers, that expect to build the number of adsorption locales and expand the adsorption capacity have been tended to. The acid pretreatments indicated great exhibitions crosswise over complex courses with costly and toxic reagents, for example, halogenations, esterification, amination, etherification, and oxidation methods. Along these lines, the test for future research is to discover an answer for these challenges to make chemically modified natural polymers sorbent that can supplant regular adsorbent materials.

Nowadays, the accumulation of toxic heavy metals in soil and water streams is considered a serious environmental problem that causes various harmful effects on plants and animals. Phytoremediation is an effective, green, and economical bioremediation approach by which the harmful heavy metals in the contaminated ecosystem can be detoxified and accumulated in the plant. Hyperaccumulators exude molecules called transporters that carry and translocate the heavy metals present in the soil to different plant parts. The hyperaccumulator plant genes can confine higher concentrations of toxic heavy metals in their tissues. The efficiency of phytoremediation relies on various parameters such as soil properties (pH and soil type), organic matters in soil, heavy metal type, nature of rhizosphere, characteristics of rhizosphere microflora, etc. The present review comprehensively discusses the toxicity effect of heavy metals on the environment and different phytoremediation mechanisms for the transport and accumulation of heavy metals from polluted soil. This review gave comprehensive insights into plants tolerance for the higher heavy metal concentration their responses for heavy metal accumulation and the different mechanisms involved for heavy metal tolerance. The current status and the characteristic features that need to be improved in the phytoremediation process are also reviewed in detail.

Emerging concern regarding the remediation of environmental pollution has expanded tremendously in recent years. Pharmaceutical industries and agricultural sectors release an enormous amount of residues containing toxic pollutants at trace levels which poses a serious impact on the environment and human health. To cope with the effect of hazardous and toxic contaminants, numerous methodologies have been developed for the treatment of effluents released from the agrochemical and pharmaceutical industries. Amongst them, photocatalysis has gained much more attention for the degradation of pollutants due to its low cost, higher capability, green and eco-friendly approaches. Photocatalysts are the substrate that plays a key role in pollutant removal through photocatalysis by accelerating the necessary chemical reactions using a light source. In this review, the recent progress on photocatalysis and its fundamental mechanism in agrochemicals and pharmaceutical pollutant degradation was summarized. This review concisely discusses the incorporation of various metal oxides and nanomaterials into semiconductors for the effective degradation of contaminants. The current status and future research on different sectors and the difficulties in the photocatalytic removal of agrochemical and pharmaceutical pollutants are also reviewed in detail.

Release of pollutants due to inflating anthropogenic activities has a conspicuous effect on the environment. As water is uniquely vulnerable to pollution, water pollution control has received a considerable attention among the most critical environmental challenges. Diverse sources such as heavy metals, dyes, pathogenic and organic compounds lead to deterioration in water quality. Demand for the pollutant free water has created a greater concern in water treatment technologies. The pollutants can be mitigated through physical, chemical and biological methodologies thereby alleviating the health and environmental effects caused. Diverse technologies for wastewater treatment with an accentuation on pre-treatment of feedstock and post treatment are concisely summed up. Pollutants present in the water can be removed by processes some of which include filtration, reverse osmosis, degasification, sedimentation, flocculation, precipitation and adsorption. Membrane separation and adsorption methodologies utilized to control water pollution and are found to be more effective than conventional methods and established recovery processes. This audit relatively features different methodologies that show remarkable power of eliminating pollutants from wastewater. This review describes recent research development on wastewater treatment and its respective benefits/applications in field scale were discussed. Finally, the difficulties in the enhancement of treatment methodologies for pragmatic commercial application are recognized and the future viewpoints are introduced.

Adsorption of Pb(II) ions in aqueous systems by newly developed mixed biomass has been explored. Mixed biomass was prepared from agro-waste (raw Banyan tree bark, RBTB) and bacterial biomass (Pannonibacter phragmitetus). Chemical modification by sulphuric acid treatment of raw banyan tree bark (SMBTB) was accomplished for the effective separation of toxic Pb(II) ions from the aquatic system. FTIR, SEM and EDX analysis was utilized to deduce sorption characteristics of mixed biomass. Pb(II) ions maximal removal has occurred at pH-6.0, lead (II) ions concentration-25 mg/L, time and mixed biomass dosage (60 min and 3.5 g/L for RBTB – Pannonibacter phragmitetus; 30 min and 1.5 g/L for SMBTB – Pannonibacter phragmitetus) and temperature (30 °C). Data from equilibrium isotherm and kinetic analysis was best suited to the Langmuir model and pseudo-first-order kinetics. The spontaneous and exothermic nature of Pb(II) ions removal was described by thermodynamic parameters. The mixed biomass proved to be an effective and potential mixed biosorbent for toxic lead removal from solutions.

In this research, dragon fruit peel, an agro-waste was used to prepare the new adsorbent for the removal of Cd(II) ions from the aquatic environment. The characterization techniques of SEM, FTIR and EDX for the prepared materials have been studied. The influential parameters for Cd(II) ions were experimented and identified the probable conditions for the maximum adsorption of Cd(II) ions. The investigations on isotherms, kinetics, and thermodynamics for Cd(II) ions removal were examined. Adsorption isotherm data was well discussed with Langmuir model based on the obtained good correlation coefficient and error values. Moreover, it follows the pseudo-first-order and exothermic process. The values of monolayer adsorption capacity of surface-modified dragon fruit peel (SMDFP) and ultrasonic-assisted dragon fruit peel (UADFP) was determined to be 7.469 and 24.76 mg/g at an equilibrium condition, respectively. This study exposed that ultrasonic-assisted dragon fruit peel can be a suitable adsorbent for Cd(II) ions removal from the water environment.

Microbial fuel cells (MFC) and microbial electrolysis cells (MEC) are developing as sustainable power source technologies that can be utilized for feasible wastewater treatment and hydrogen production. Hydrogen gas has immense potential as an ecologically adequate energy carrier for vehicles. MFC is bioelectrochemical process that utilize microorganism as the impetuses to oxidize organic and inorganic matter and create electricity, whereas MEC are a reactor for biohydrogen production by combining MFC and electrolysis. MEC and MFC have been the cleanest, eco-friendly, and efficient method for biohydrogen production. The basic mechanism and thermodynamic principles involved in the production of hydrogen have been discussed in brief. Effective factors influencing H2 production such as microbial population, electrodes, membrane, and substrate were elaborated and recent advances in the factors have been explored for the better understanding of developing MFC and MEC technology-based hydrogen generation. This review completes a brief outline of topical advances in the MFC, MEC setup, and different operational parameters which influencing hydrogen production (ionic strength, applied voltage, organic loading, and hydraulic retention time). The review describes the current challenges involved in the technology used and provides effective future perspectives for overcoming the limitations.

Immobilized fungal biomass (Aspergillus niger and Aspergillus flavus) was prepared and analysed for the simultaneous removal of Cu(II) ion and Reactive Green 6 dye from aqueous phase. Different characterization analysis was utilized to exploit the adsorption characteristics of fungal biomass. Batch biosorption tests, performed to investigate the factors influencing biosorption process inferred optimal values of 25 mg/L of adsorbate with equilibrium time of 60 min, 2.5 g of immobilized fungal biomass, temperature of 303 K and pH of 5.0 for the maximal removal of pollutants. The obtained experimental data was utilized to evaluate the kinetic, thermodynamic and equilibrium models. Langmuir isotherm model has higher correlation coefficient [Cu(II) ion = 0.8625 and RG 6 dye = 0.8575] with small values of errors (RMSE = 3.746 and SSE = 56.12 for Cu(II) ion; RMSE = 4.872 and SSE = 11.87 for RG 6 dye). Kinetic studies performed to evaluate the adsorption rate mechanism of this present study indicated that pseudo-first order and pseudo-second order kinetics to be most fitting model for removal of Cu(II) ions and Reactive green dye respectively. Thermodynamic analysis inferred the spontaneous, random, and exothermic nature of the biosorption process based on ΔGo, ΔHo, and ΔSo values respectively. The prepared biomass can be an alternative for the elimination of toxic pollutants from wastewater.

Nanotechnology has become one of the emerging multi-disciplinary fields receiving universal attention and playing a substantial role in agriculture, environment and pharmacology. In spite of various techniques employed for nanoparticle synthesis such as laser ablation, mechanical milling, spinning and chemical deposition, usage of hazardous chemicals and expensiveness of the process makes it unsuitable for the continuous production. Hence the necessity of sustainable, economic and environment friendly approach development have increased in recent years. Microbial synthesis of nanoparticles connecting microbiology and nanotechnology is one of the green techniques employed for sustainable production. Gold, silver and other metal nanoparticles like platinum, palladium, molybdenum nanoparticles biosynthesis by bacteria, fungi, yeast and algae have been reported in the present review. On account of microbial rich community, several microbes have been explored for the production of nanoparticles. Nanoparticles are also employed for environmental remediation processes such as pollutant removal and detection of contaminants. Lack of monodispersity and prolonged duration of synthesis are the limitations of bio-synthesis process which can be overcome by optimization of methods of microbial cultivation and its extraction techniques. The current review describes the different microbes involved in the synthesis of nanoparticles and its environmental applications.

Huge amount of food waste (FW) is turning into a worldwide concern. The food-processing industry creates enormous volumes of wastes, both solids and liquids, generated from the production, preparation, and consumption of food. The utilization of FW as feedstock in biorefineries is in the starting phase of progression, and a number of studies are surveying its financial feasibility at a large scale. The source of the waste is also classified into agricultural waste, FW, and municipal waste. Here we focus on the creations of economic value from complex organic wastes, for example, FW. The use of FW in biorefineries is anticipated as a potential system to add to the achievement of the required targets and, in the meantime, to decrease the usage of both fossil and bio-based resources, supporting the change to a circular bioeconomy. FW biorefinery idea includes (1) evaluating the available quantities of FW to be utilized as feedstock; (2) due to the low innovation availability level of this sort of biorefinery, a screening technique to evaluate the speculation and assembling costs. This chapter covers the interaction of FW with biorefineries and recycling, and reuse of FW.

Membrane technology plays an increasingly urgent part in the purging of biotechnologic items. Combination of membrane-based unit activities turns into a pattern for continuous process outlines. The capability of membrane partition methods, for example, microfiltration, ultrafiltration, nanofiltration, reverse osmosis, and electrodialysis, and layer reactors in the treatment of maturation juices are immense. The synergistic impacts realized by outlining the general biotechnologic process consolidating different membrane strategies are especially huge. Segregation is frequently extremely intense, allowing substances having fundamentally the same piece and structure to be either passed or prohibited. The straightforwardness with which extremely troublesome choices in the entry of segments is acknowledged is declaration to the useful impacts of centuries of regular determination. This chapter manages distinctive parts of layer filtration and how layers can be connected in various phases of the downstream processing.

Microbial fuel cell (MFC) is one of the promising alternative energy systems where the catalytic conversion of chemical energy into electrical energy takes places with the help of microorganisms. The basic configuration of MFC consists of three major components such as electrodes (anode and cathode), catalyst (microorganism) and proton transport/exchange membrane (PEM). MFC classified into four types based on the substrate utilized for the catalytic energy conversion process such as Liquid-phase MFC, Solid-phase MFC, Plant-MFC and Algae-MFC. The core performance of MFC is organic substrate oxidation and electron transfer. Microorganisms and electrodes are the key factors that decide the efficiency of MFC system for electricity generation. Microorganism catalysis degradation of organic matters and assist the electron transfer to anode surface, the conductivity of anode material decides the rate of electron transport to cathode through external circuit where electrons are reduced with hydrogen and form water with oxygen. Not limited to electricity generation, MFC also has diverse applications in different sectors including wastewater treatment, biofuel (biohydrogen) production and used as biosensor for detection of biological oxygen demand (BOD) of wastewater and different contaminants concentration in water. This review explains different types of MFC systems and their core performance towards energy conversion and waste management. Also provides an insight on different factors that significantly affect the MFC performance and different aspects of application of MFC systems in various sectors. The challenges of MFC system design, operations and implementation in pilot scale level and the direction for future research are also described in the present review.

Nowadays, over utilization of pesticides in agricultural sector has considered being a high threat to human beings and aquatic animals. Pseudomonas stutzeri was isolated from the pesticide-contaminated crop field, Vaniyambadi, India and identified by the 16S rRNA sequencing method. The agricultural by-product biomass - Delonix regia seeds, which are not useful for any purpose, were collected and their surface was modified using concentrated H 2 SO4, and then used as a bioadsorbent to eradicate available pesticide present in soil and water environment. The readied bacterial biomass and agro-waste bioadsorbent are classified by Scanning Electron Microscope, Energy Dispersive X-ray spectroscopy and Fourier-transform Infrared Spectroscopy investigations. Blending sulphuric acid modified Delonix Regia seeds with microbe explicit degradation pathways could comprise an important procedure to remove toxic as well as uncontrollable pesticides present in soil and water. Ultraviolet–visible spectrophotometer as well as Gas chromatography-mass spectrometry analysis assured elimination of chlorpyrifos present in soil and water environment, also, the percentage removal of chlorpyrifos shoot up for the 14th-day samples (water and soil) are calculated as 95.29% and 93.10%, respectively. Potential application methods of the considered biodegradation procedure were additionally discussed. This study reveals that the prepared mixed bioadsorbent has greater potential to remove chlorpyrifos from the pesticide-contaminated water and soil.

Different ammonium cation containing anion exchange membranes are investigated in this study. Anion exchange polymers have been prepared from styrene and vinylbenzyl chloride monomers by free radical polymerization, followed by a quaternization process. Amines such as trimethylamine (TMA), tris(trimethylsilyl)amine (TTSA), hexamine (HMA), N,N,N′,N′-tetramethyl hexanediamine (TMHDA), and N,N,N′,N′-tetramethyl ethylenediamine (TMEDA) are used in this study. FT-IR and 13C-NMR results confirm the successful quaternization of the co-polymers with different amines. TGA results reveal that the thermal stability of the anion exchange polymers is as high as 165 °C. SEM images show that the membrane morphological features are tuned by the different ammonium cations. The ionic conductivity, ion-exchange capacity and water uptake values of the membranes also change with the different ammonium cations, which reveal the distinctive roles of the different amines used. Among the membranes, the membrane containing the trimethylammonium (TMA+) cation demonstrates the highest ionic conductivity, ion-exchange capacity and water uptake. On the other hand, the hexaminium (HMA+) containing anion exchange membrane displays the lowest ionic conductivity, ion-exchange capacity and water uptake due to the highly entangled structure of the polymer caused by the cross-linking of the polymer units.