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Organic matter may be converted to energy through various methods, but the most preferable one is the Anaerobic Digestion (AD), specifically for biogas production. In sustainable bioenergy production, it can undoubtedly be called one of the most widely used methods from the various feedstock. Over the past years, algae waste has become an increasingly acute environmental problem but luckily it can be used as feedstock to produce bioenergy. In order to improve the energy productivity of green algae, this study is focused on the introduction of cobalt (Co) nanoparticles (NPs) in the AD process. The concentration of Co NPs was optimized using response surface methodology (RSM). Mesophilic temperature range (25–45 °C), initial pH (5–9) and Co NPs dosage (0.5–2 mg/L) were selected as the independent variables for RSM. The results indicated that at optimized values (Co NPs concentration = 1 mg/L, initial pH = 7, and digestion temperature = 35 °C) produced the highest biogas yield of 298 ml. An experiment was carried out at optimized conditions to explore the effect on biogas production. The results showed that Co NPs had a positive influence on biogas yield. The low concentrations achieved higher biogas production as compared to higher ones. A maximum biogas yield of 678 mL is achieved by Co NPs (1 mg/L). AD performance was further evaluated by the modified Gompertz model. Different kinetic parameters were calculated. The values of the performance indicators confirmed that the mathematical model fitted well with experimental data.

Over the last few decades, steady growth in desalination literature has been observed. However, conducting a quantitative analysis of this literature is still a novelty. This study aimed at carrying out a quantitative analysis of desalination literature published during the last 30 years, using bibliometric and content analysis techniques, based on the Web of Science database. The bibliometric analysis revealed that desalination has received much attention after the year 2000, as 95.4% of literature has been published in two decades after 2000. The text mining analysis showed that the hot themes of desalination research are reverse osmosis optimization, graphene implications, interfacial polymerization, capacitive deionization, carbon nanotube implications, and antifouling techniques. Furthermore, it was observed that many desalination technologies have emerged recently that make it a challenge to choose the right desalination technology for industrialization. Therefore, this study also contributed to identifying the factors that are important for the industrialization of desalination technologies and, based on these identified factors, this study has compared different desalination technologies to unearth the energy-efficient and low production cost technology. Analytical hierarchy process was used for comparing existing desalination technologies based on eight different parameters and it demonstrated that reverse osmosis is the best available technology for desalination.

The human race of industrialization without oblivious to environmental contaminants has attracted attention of researchers for development of chemical sensors to detect, measure and mitigate drastically detrimental effects of anthropogenic pollutants. A wide congregation of chemical sensors is available in market but a few factors such as cost, accuracy, time of response, sensitivity, operating environment (temperature and pressure range) and power consumption urges to improve and optimize sensors. For this purpose, various varieties of material, covering polymers and semiconductors to nano particles, have been utilized for manufacturing of chemical sensors. Recently, a tremendous paradigm shift has been observed due to introduction of gallium nitride (GaN) in chemical sensing applications. The aim of this paper is to review recent unprecedented sensing utilizations of GaN, in terms of chemical sensing and power applications.

Algae waste is one of the potential substrates for biogas and biohydrogen production and can comprehend multiple benefits of waste treatment and resource utilization. In view of the key bottlenecks such as low substrate degradation rate and poor productivity of algae waste production process, this study analyzes the combined effect of two metallic and metallic oxide nanoparticles with different substrate pretreatment methods (autoclave, ultrasonic, and microwave methods) to investigate the effect of anaerobic digestion of green algae (Enteromorpha). The results showed that out of the three pretreatment methods, microwave pretreatment and nanoparticles' synergistic effect significantly increases biogas production. The microbial community composition at the phylum level was analyzed. It was observed that the Firmicutes were most abundant across all samples. The relative abundance of Firmicutes for control, Ni NPs + MW, Co NPs + MW, and Fe3O4 NPs + MW groups were 51.78, 70.37, 75.77, and 83.93%, respectively. The second most abundant was of Bacteroidetes that also contributes to hydrogen production. This relatively high abundance of Firmicutes and Bacteroidetes promises its potential applications in a hydrogen production facility. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Due to their simple synthesis method and excellent properties, such as superior adsorption and regeneration capabilities, with a large surface area and tunable pores, metal-organic frameworks (MOFs) have emerged as a suitable option for wastewater treatment. Although an exponential growth in MOF literature has been observed in recent years, conducting a quantitative literature analysis of MOF application in wastewater treatment is a novelty. To fill this gap, a total of 1187 relevant publications were extracted from the Web of Science, published during the last 50 years, and analyzed using bibliometric and content analysis techniques. A bibliometric analysis was conducted to reveal growing publication trends, leading journals, prolific countries, and organizations; whereas, a content analysis was used to highlight key research themes and hot topics in this field. The analyses revealed that there is a strong international collaboration among authors, countries, and organizations. Chemical Engineering Journal, Journal of Hazardous Materials, and Journal of Environmental Chemical Engineering are the most prolific journals in this field. Furthermore, the use of MOFs for removing antibiotics from wastewater was identified as a recent hot topic. In addition, performance enhancements of MOFs, in terms of a higher adsorption capacity and water stability, were identified as topics of great interest. To cater to these issues, the application of graphene, graphene oxides, nanoparticles, and quantum dots was also observed in the research fronts in this field.

The growing energy demand and arousing environmental concerns are some of the major issues faced all over the globe. Excessive CO2 release has always been devastating the human ecosystem but in recent years historically high emission of CO2 from the energy sector has drawn much attention towards clean and green fuel. In this regard, methanol synthesis is a pivot to the research community as a clean fuel. This book chapter also strives to highlight the methanol synthesis process by performing thermodynamic analysis. A deliberate energy analysis of methanol synthesis by reverse water-gas shift reactor (rWGSR) is performed. The thermochemical processing is utilized to convert methane and carbon dioxide to methanol. On the basis of thermodynamic modelling, concentrations of different constituents over the cycle are determined. It is verified that the optimum state of methanol synthesis is accompanied by the lowest level of CO. Moreover, the concentration of carbon dioxide doesn’t affect the methanol synthesis significantly.

The future advancements in wireless communication and the network technology is facing new challenges under different circumstances. These challenges are emerging out as revolutionary invention roadmaps. This study strives to contribute in wireless communication and networking systems. A rectangular microstrip patch antenna is proposed. Initially, some common mediums of communication such as WIFI/WLAN and Bluetooth were targeted. The successful execution leads us to target the commons bandwidth of wireless communication i.e. 2.4 and 5 GHz. The dielectric substrate material used for this purpose was FR4 with 1.6 × 38 × 39.8 mm dimensions (thickness × width × height). The design and simulation on HFSS V15.0 revealed the peak at 2.4 and 5 GHz. These results were also verified through 3D polar plot. After successful simulation, the next step was fabrication. DipTrace circuit design tool was used to generate Gerber file and was printed it on glossy paper followed by printing of antenna on substrate. To remove copper surrounding, FeCl3 and butyl solutions were used followed by soldering of SMA, for successful transmission. The simulation results were empirically verified by using VNA (Vector Network Analyzer). The proposed antenna shows significant negative environmental effect on its transmission. The return loss is quantified as -13dB and -27dB at 2.4 and 5 GHz, respectively. In addition, it promises swift and economic transmission of data with minimum noise attenuation requirement.

The ecosystem of earth, the habitation of 7.53 billion people and more than 8.7 million species, is being imbalanced by anthropogenic activities. The ever-increasing human population and race of industrialization is an exacerbated threat to the ecosystem. At present, the global average waste generation per person is articulated as 494 kg/year, an enormous amount of household waste (HSW) that ultimately hits 3.71&times, 1012 kg of waste in one year. The ultimate destination of HSW is a burning issue because open dumping and burning as the main waste treatment and final disposal systems create catastrophic environmental limitations. This paper strives to contribute to this issue of HSW management that matters to everyone&rsquo, s business, specifically to developing nations. The HSW management system of the world&rsquo, s 12th largest city and 24th most polluted city, Karachi, was studied with the aim of generating possible economic gains by recycling HSWs. In this regard, the authors surveyed dumping sites for sample collection. The sample was segregated physically to determine the content type (organic, metals, and many others). Afterward, chemical analysis on AAS (Atomic Absorption Spectrophotometry) of debris and soil from a landfill site was performed. HSW is classified and quantified into major classes of household materials. The concentrations of e-waste [Cu], industrial development indicator [Fe], and the main component of lead-acid storage batteries [Pb] are quantified as 199.5, 428.5, and 108.5 ppm, respectively. The annual generation of the aforementioned metals as waste recovery is articulated as 1.2 &times, 106, 2.6 &times, 106 and 6.5 &times, 105 kg, respectively. Significantly, this study concluded that a results-based metal recovery worth 6.1 million USD is discarded every year in HSW management practices.

This chapter centers around the portrayal of metal oxides powder which represents the one of the foremost common and diverse category of materials with respect to their mechanical, chemical, and electrical properties. The material characteristics such as electric, magnetic, optical, and thermal behaviors are being versatile for technological advancements. In this chapter the fundamentals of dielectric materials and nanostructured metal oxides powder (dependent on titanium dioxide, zinc oxide, alumna, copper oxide, and tin oxide) are mentioned and discussed. In terms of future application, these nanostructured metal oxides powder are very vital for novel devices after a gracious controlled care of composition, structure, and surface properties. These metal oxides are treasure for their applications in versatile scope of industries such as water purification and medical. As metal oxide powder exhibits mentioned special properties, its consideration can be advantageous especially to cosmetics industry and personal care products. Along with described benefits, these oxides may also have hazardous effects on people, amphibian, and environment. Discussion of all applications and effects of metal oxide nanomaterials is very vast and cannot be cove at once. Hence, a summarized literature review of metal oxide nanomaterial’s ecotoxicological effects is considered as main focus. Moreover, nanoscaled surface functionalization of these oxides will also be discussed.

SiGe being one of the most diverse, emerging and richest material for MOSFETs is alluring the scientist due to its unique characteristics like high performance, high surface channel mobility and low threshold voltage as compare to that of silicon MOSFETs. In spite of so much cruciality, the performance of SiGe MOSFETs is being controlled by several factors like resistance and junction depth. These factors urged scientists to not relieve on the traditional methods of junction meteorology to utilize the actual potential and high performance of SiGe MOSFETs in terms of their application. Hence, a paradigm shift in junction engineering is being observed during last few years and discussed. The main focus of this paper is to highlight junction metrologies (ion implantation and annealing) that were tested on SiGe MOSFETs and to propose the most efficient and sustainable technique of junction engineering for high performance applications.SiGe being one of the most diverse, emerging and richest material for MOSFETs is alluring the scientist due to its unique characteristics like high performance, high surface channel mobility and low threshold voltage as compare to that of silicon MOSFETs. In spite of so much cruciality, the performance of SiGe MOSFETs is being controlled by several factors like resistance and junction depth. These factors urged scientists to not relieve on the traditional methods of junction meteorology to utilize the actual potential and high performance of SiGe MOSFETs in terms of their application. Hence, a paradigm shift in junction engineering is being observed during last few years and discussed. The main focus of this paper is to highlight junction metrologies (ion implantation and annealing) that were tested on SiGe MOSFETs and to propose the most efficient and sustainable technique of junction engineering for high performance applications.

Solid waste management needs re-evaluating in developing countries like Pakistan, which currently employs landfilling as a first option. Over time, increasing population will result in decreasing space for landfill sites, ultimately increasing the cost of landfilling, while increasing accumulated waste will cause pollution. Locating and preparing a sanitary landfill includes the securing of large sectors and also everyday activity with the end goal to limit potential negative impacts. Energy production from municipal solid waste (MSW) is a perceptive idea for large cities, such as Karachi, as waste, which is an undesirable output that adds to land and air pollution, is transformed into a vital source of energy. The current study strives to provide a destination to solid waste by evaluating the energy potential that waste provides for power generation by the process of incineration. A sustainable energy generation plant based on the Rankine cycle is proposed. This study evaluates the various landfill sites in the case study area to determine their sustainability for a waste to energy (WtE) plant. The implementation of the proposed plant will not only provide an ultimate destination to waste but also generate 121.9 MW electricity at 25% plant efficiency. Thus, the generated electricity can be used to run a WtE plant and meet the energy requirements of the residents.