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Schematic diagram of solvochars/catalytic solvochar production and application for multi-heavy metal ion adsorption.

The concept of green chemistry has attracted attention due to the green synthesis and ecofriendly nature of the compounds leading to the green and sustainable chemical industries and processes. Chitosan is an ecofriendly material, which is biodegradable, non-toxic, and biocompatible. It has the potential to be modified into biofilms for various applications such as biomedical, packaging, and pharmaceutical fields. Nevertheless, some poor properties of chitosan restrict its wide applications. The incorporation of nanocellulose fillers into chitosan matrix can enhance the mechanical and thermal properties of chitosan. Cellulose nanomaterials can be achieved through chemical and mechanical modifications. The common type of nanocellulose are cellulose nanofibers (CNFs), cellulose nano-whiskers (CNWs), tunicate CNCs (t-CNCs), algae cellulose particles (AC) and bacterial cellulose particles (BC). Nanocellulose are applied as the reinforcement fillers in various polymer matrices such as polysaccharides, proteins, lipids, polylactic acid etc. Deep eutectic solvents (DES) are relatively novel green solvents, which can be applied in various fields. DES are widely applied in metal processing, polymer processing and synthesis. Even though there are not much studies available on DES for synthesis of nanocomposite films; however they are used as eco-friendly solvents in manufacturing processes. This study reviews the discovery, structure, properties of chitosan and cellulose, their derivatives and applications. In addition, the paper also discusses the properties of DES and their applications.

Synthesis of hybrid nanomaterials in the lab-scale frequently involves complex processing and often is not able to be adopted in the industry without major enhancements for its commercial production. This research is focused on a convenient route for the fabrication of chitosan-supported magnetically recoverable carbon bio-nanocomposites by functionalizing magnetic nanoparticles on chitosan and renewable carbon material using solvothermal carbonization co-precipitation (STCC). This process can be adopted in large-scale synthesis with minimum enhancements. The nanocomposites produced using STCC offered excellent features including porous and ultrafine nanostructure, stable mechanical, and chemical properties. From the analysis of variance (ANOVA), the temperature has been found to be the most influential factor for both magnetic nanocomposite and bio-oil yield. The highest porosity for nanocomposites was observed with water-based synthesis at 260 °C at 194.62 m2/g. However, water/ethanol (50:50) at 260 °C yielded 6.67% and 8.01% more bio-oil and having 5.35% and 3.49% higher heating value as compared to that of bio-oil produced using water and ethanol.

Oil spills are a major contributor to water contamination, which sets off a significant impact on the environment, biodiversity, and economy. Efficient removal of oil spills is needed for the protection of marine species as well as the environment. Conventional approaches are not efficient enough for oil-water separation; therefore, effective strategies and efficient removal techniques (and materials) must be developed to restore the contaminated marine to its normal ecology. Several research studies have shown that nanotechnology provides efficient features to clean up these oil spills from the water using magnetic nanomaterials, particularly carbon/polymer-based magnetic nanocomposites. Surface modification of these nanomaterials via different techniques render them with salient innovative features. The present review discusses the advantages and limitations of conventional and advanced techniques for the oil spills removal from wastewater. Furthermore, the synthesis of magnetic nanocomposites, their utilization in oil-water separation, and adsorption mechanisms are discussed. Finally, the advancement and future perspectives of magnetic nanocomposites (particularly of carbon and polymer-based magnetic nanocomposites) in environmental remediation are presented.

Emerging pollutants (EPs) in the environment have become a significant source of pollution and cause of serious concern for the ecosystem and human health. Although during the recent decades, extensive research has been performed worldwide for the detection and analysis of EPs, continuous refinement, and development of specific analytical techniques; a great number of undetected EPs still need to be investigated in different components of the ecosystem and biological tissues. Therefore, this chapter provides extensive reviews of several emerging pollutants reported around the globe along with their physiochemical properties and potential ecological impacts. Moreover, formulated legislations and policy regulations for the monitoring of EPs are also discussed in this chapter.

The objective of this study is the applications of hybrid magnetic nanocomposites as catalyst as well as an adsorbent. Four magnetic nanocomposites (graphene and chitosan based) were fabricated using single pot solvothermal carbonization co-precipitation (STCC) route by integrating biomass functionalized with iron oxide nanoparticles. All hybrid nanocomposites were characterized for their magnetic, thermal, chemical and structural properties. Adsorption isotherms and kinetics studies were performed for adsorption of multi-heavy metals including Cd, Ni, Cu and Cr. Finally, the hybrid magnetic carbon nanocomposites were tested as catalysts to produce bio-oil through catalytic liquefaction of rice husk in supercritical ethanol. It was found that the bio-oil yield and overall conversion was enhanced significantly from 29.5% and 48.11% without catalyst, to 36.8% and 60.81% respectively with the presence of magnetic carbon nanocomposites as catalyst. Furthermore, the bio-oil energy quality was enhanced in energy content from 21.72 to 23.21 MJ/kg with the presence of catalyst and H/C and O/C ratios were reduced. Finally, GCMS revealed that the bio-oil produced using catalysts showed higher mass fraction of esters, hydrocarbons and reduced acid groups as compared to bio-oil. This study provides insights to the understanding of the role of hybrid magnetic nanocomposites for its expansion for future applications.

In this work, the effect of ionic liquid (IL) pretreatment on the pyrolytic behavior of lignite was analyzed by examining reactivity, kinetic, and thermodynamic parameters. Pretreatment of lignite ...

Summary Cystic echinococcosis (CE) is a zoonotic disease caused by the larval stage of Echinococcus granulosus tapeworms. These parasites have a worldwide geographic distribution and pose a serious threat to livestock industry as well as human health in the endemic areas. CE is widely distributed in Pakistan. However, very few reports are available related to the regional transmission of E. granulosus. A retrospective analysis was conducted of surgically confirmed CE patients who were treated at Shoukat Khanum Memorial Cancer Hospital and Research Centre in Lahore, Punjab Province, Pakistan from 2007 – 2018. In total, 536 CE patients were evaluated during the study period. Cases originated from the provinces of Khyber Pakhtunkhwa (n=336), Punjab (n=147), Baluchistan (n=18), Sindh (n=3), Islamabad (n=2), Gilgit Baltistan (n=1), and Azad Jammu and Kashmir (n=1). An additional 28 cases were from Afghanistan. The highest number of CE cases was reported in 2013 (n=90). Females made up a larger proportion of cases (n=310; 57.8 %) than males (n=226; 42.2 %). Most patients were members of the Pashtun (n=197; 36.7 %), Hindku (n=142; 26.5 %), and Punjabi (n=118; 22.0 %) ethnic groups. The largest number of cysts was obtained from the liver (137/536; 25.6 %). This study showed that CE is likely present throughout Pakistan. In order to control the disease, a comprehensive control program and regional surveillance are needed.

Toxic cationic dyes are used in different textile industries. When the colour interacts with the sunlight, it causes incomplete photosynthesis, inhibiting aquatic organisms’ growth and disrupting gas permeability in the water system. In this work, carbon nanotubes (CNTs) were prepared to employ acetylene and hydrogen as precursor gases in a microwave-assisted reactor. The obtained CNTs were tested for their ability to remove the crystal violet (CV) dye. However, the effect of removal parameters, such as pH of ion solution, initial concentration, and contact time, was optimized on the adsorption process through response surface methodology. It was found that the optimized removal of CV dye was 81% at an optimum pH value of 7.0 with 10 mg/L of an initial concentration and a contact time of 25 min. Complete dye extraction can be achieved by increasing the CNT dosage.Moreover, by using both the Langmuir model and Freundlich model of adsorption, the equilibrium data obtained from experiments were analyzed. The study also revealed that the adsorption at room temperature, having a high adsorption capability of 2.615 mg/g for CV, was best defined using the Langmuir model. For the reaction order, the adsorption rates represented the pseudo-first-order kinetic model.

This study aims to investigate the role of water and ethanol in ethanol/water mixed solvent system, co-liquefaction of high-density polyethylene (HDPE) and sugarcane bagasse (SCB) to produce high quality bio-oil. It was revealed that various ethanol/water mixing ratios led to various reaction mechanisms, which indicates that there is a clear synergy effect between water and ethanol liquefaction process in three reaction media. The conversion and bio-oil yield approach were in the order of pure water

Hydrothermal carbonization (HTC) and its parameters show a significant role in the quality of HTC products and the distribution of yield. The present study investigates the optimal conditions that are suitable to produce maximum yield products of solid, liquid, and gas, from HTC of oil palm trunk (OPT), by following the Taguchi method. Moreover, all the three products of HTC were analyzed using various characterizations. The optimum runs for hydrochar yield, liquid yield, and gaseous yield were run 1 (R1), run 4 (R4), and run 9 (R9), respectively. The reaction temperature was found to be the most influential parameter that affected the yield distribution during HTC, where low temperature supported solid production, intermediate temperatures favored liquid yield, and high temperature produced higher gaseous yield. Elemental analysis, H/C and O/C atomic ratios, higher heating value (HHV), and energy density values of hydrochar recommended that the HTC process has significantly converted OPT into better energy fuel. The energy densification value of hydrochar ranged between 1.28 and 1.40, which confirmed the significance of the HTC process. Two characteristic peaks from FTIR were observed at 3,430 cm−1 and 2,923 cm−1 hydrochar. SEM analysis confirmed that the porosity of hydrochar was higher than OPT after HTC. However, the major organic matter in the bio-oil traced by GC-MS analysis was acetic acid, accounting for about 59.9–71.7%, and the outlet gaseous product consisted of 0.87–9.17% CH4, 3.88–29.02% CO2, 1.07–7.89% CO, and 0.31–1.97% H2, respectively, as shown by GC-TCD.

Numerous contaminants in huge amounts are discharged to the environment from various anthropogenic activities. Waterbodies are one of the major receivers of these contaminants. The contaminated water can pose serious threats to humans and animals, by distrubing the ecosystem. In treating the contaminated water, adsorption processes have attained significant maturity due to lower cost, easy operation and environmental friendliness. The adsorption process uses various adsorbent materials and some of emerging adsorbent materials include carbon- and polymer-based magnetic nanocomposites. These hybrid magnetic nanocomposites have attained extensive applications in water treatment technologies due to their magnetic properties as well as combination of unique characteristics of organic and inorganic elements. Carbon- and polymer-related magnetic nanocomposites are more adapted materials for the removal of various kinds of contaminants from waterbodies. These nanocomposites can be produced via different approaches such as filling, pulse-laser irradiation, ball milling, and electro-spinning. This comprehensive review is compiled by reviewing published work of last the latest recent 3 years. The review article extensively focuses on different approaches for producing various carbon- and polymer-based magnetic nanocomposites, their merits and demerits and applications for sustainable water purification. More specifically, use of carbon- and polymer-based magnetic nanocomposites for removal of heavy metal ions and dyes is discussed in detail, critically analyzed and compared with other technologies. In addition, commercial viability in terms of regeneration of adsorbents is also reviewed. Furthermore, the future challenges and prospects in employing magnetic nanocomposites for contaminant removal from various water sources are presented.

Roads play a crucial role in the economic development of nations; reconstruction, resurfacing, or rehabilitation of the current roads result in the milling of approximately 120 million tons of asphalt pavement every year. Due to the significant volume of resources involved, road agencies constantly trade-off among economic, performance and environmental challenges to maintain and build road assets. To address these challenges – such as reducing the dependency on non-renewable petroleum-based products and minimising waste and landfills – recycling of end of life road material through various organic binders has been evaluated. Bio-oil, obtained through recycling of different sources, contains lower molecular weight components that resemble fractions of the virgin asphalt binder used to make roads. This review article focuses on the recycling of bio-oil and its utilization in asphalt binders – as an alternative, extender, modifier and rejuvenator – and asphalt mixes. This review paper provides information on the production methodology used to produce bio-oil from various types of biomass, along with upgradation techniques adopted to upgrade the bio-oil before its addition into bitumen. The chemical and physical properties of bio-oils vary for each type of biomass. The production methodology to produce bio-binder from bio-oil is also specified. Simultaneously, the effect of bio-oil on the mechanical, rheological and chemical properties are compared with those of conventional bitumen. It is concluded that the performance of bio-binder varies with the type of bio-oil used for the modification, generally improving the intermediate and low-temperature viscoelastic behaviour but reducing the high-temperature performance. This review article provides a sketch of favourable and harmful aspects associated with the utilization of bio-oil to form bio-binders.

This study aims to investigate the co-liquefaction of high-density polyethylene (PE) and low density polyethylene bags (PB) with sugarcane bagasse (SCB) in supercritical ethanol solvent. The effect of blending ratios of SCB/PB and SCB/PE is studied. Results indicate that blending ratio of low density plastic bags and high-density polyethylene impacts the product distribution during solvo-thermal process. The optimum conversion of SCB/PE and SCB/PB up to 57.3% and 59.4% with bio-oil yields of 31.5% and 30.3% respectively are obtained at 280 °C. The higher heating values (HHV) of bio-oil obtained from SCB/PE and SCB/PB are 34.9 and 34.8 MJ/kg, respectively. CHNS/O, chemical composition, carbon and proton NMR, Thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FTIR) analyses of bio-oil have been conducted. Investigation suggests that the SCB/PE and SCB/PB derived bio-oil have the superior qualitative properties compared to pure sugarcane bagasse.

Substantial discharge of hazardous substances, especially dyes and heavy metal ions to the environment, has become a global concern due to many industries neglecting the environmental protocols in waste management. A massive discharge of contaminantsfrom different anthropogenic activities, can pose alarming threats to living species and adverse effect to the ecosystem stability. In the process of treating the polluted water, various methods and materials are used. Hybrid nanocomposites have attained numerous interest due to the combination of remarkable features of the organic and inorganic elements in a single material. In this regards, carbon and polymer based nanocomposites have gained particular interest because of their tremendous magnetic properties and stability. These nanocomposites can be fabricated using several approaches that include filling, template, hydrothermal, pulsed-laser irradiation, electro-spinning, detonation induced reaction, pyrolysis, ball milling, melt-blending, and many more. Moreover, carbon-based and polymer-based magnetic nanocomposites have been utilized for an extensive number of applications such as removal of heavy metal and dye adsorbents, magnetic resonance imaging, and drug delivery. This review emphasized mainly on the production of magnetic carbon and polymer nanocomposites employing various approaches and their applications in water and wastewater treatment. Furthermore, the future opportunities and challenges in applying magnetic nanocomposites for heavy metal ion and dye removal from water and wastewater treatment plant.

Photo-Fenton oxidation is one of the most promising processes to remove recalcitrant contaminants from industrial wastewater. In this study, we developed a novel heterogeneous catalyst to enhance photo-Fenton oxidation. Multi-composition (Fe-Cu-Zn) on aluminosilicate zeolite (ZSM-5) was prepared using a chemical process. Subsequently, the synthesized catalyst was characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (spectroscopy) (EDX), and Brunauer-Emmett-Teller (BET). Activity of the synthesized catalyst is analysed to degrade an azo dye, methyl orange. Taguchi method is used to optimize color removal and total carbon content (TOC) removal. The dye completely degraded, and 76% of TOC removal was obtained at optimized process conditions. The amount of catalyst required for the desired degradation of dye significantly reduced up to 92% and 30% compared to conventional homogenous and heterogeneous Fenton oxidation processes, respectively.

Due to the rapid growth in the heavy metal-based industries, their effluent and local dumping have created significant environmental issues. In the past, typically, removal of heavy metals was handled by reverse osmosis and ion exchange techniques, but these methods have many disadvantages. Therefore, extensive work into the development of improved techniques has increased, especially for heavy metal removal. Many countries are currently researching new materials and techniques based on nanotechnology for various applications that involve extracting heavy metals from different water sources such as wastewater, groundwater, drinking water and surface water. Nanotechnology provides the possibility of enhancing existing techniques to tackle problems more efficiently. The development in nanotechnology has led to the discovery of many new materials such as magnetic nanoparticles. These nanoparticles demonstrate excellent properties such as surface-volume ratio, higher surface area, low toxicity and easy separation. Besides, magnetic nanoparticles can be easily and efficiently recovered after adsorption compared with other typical adsorbents. This review mainly emphasises on the efficiency of heavy metal removal using magnetic nanoadsorbent from aqueous solution. In addition, an in-depth analysis of the synthesis, characterisation and modification approaches of magnetic nanoparticles is systematically presented. Furthermore, future opportunities and challenges of using magnetic particles as an adsorbent for the removal of heavy metals are also discussed.

The extraction of concentrated volatile oils from various plant species is generally carried out by hydrodistillation technique. However, this hydrodistillation technique is expensive owing to more solvent and energy consumption. In this study, effect of ultrasonic pre-treatment prior to hydrodistillation on extraction of Cinnamomum cassia bark oil was evaluated. Process variables for extraction were optimized by Taguchi method. Results revealed that ultrasound pre-treatment hydrodistillation (UAHD) can enhance the yield of the extracted oil when compared with conventional hydrodistillation (HD) technique. To predict the yield of the extracted essential oil significant mathematical model was developed. Optimum parameters were determined according to the mathematical model they were: solid loading 25 g, ultrasound power 600 W, extraction time 35 min, and solvent quantity 100 ml. Further, gas chromatography–mass spectrometry (GC–MS) results of C. cassia bark oil revealed that UAHD produced more oxygenated compounds than HD extraction method. In addition, UAHD was found to be less energy consuming and environmentally safer than HD extraction method. Moreover, FT-IR spectra indicate that the effect of UAHD extraction method released all the volatile compounds from treated C. cassia bark powder. Finally, the optimum parameters were confirmed by the experiments performed, in which the yield of the oil of 3.17% was obtained. This study demonstrated that ultrasound pre-treatment prior to hydrodistillation could be useful to extract bioactive compounds with reduction in extraction time for extraction of C. cassia bark oil.