A modified controlled chemical co-precipitation of alkaline aqueous ferrous and ferric salt solution at pH 8 with continuous addition of ammonia solution 25% under a degassed atmosphere was performed to synthesis magnetite (Fe3O4) nanoparticles. Formation of magnetite nanoparticles was conducted by adjusting the ferric to ferrous ions in the ratio of 1:1, 1:2 and 2:1. Further investigation on the surfactant-coated magnetite nanoparticles by using 8% surfactant sodium dodecyl sulphate (SDS) was also studied. The synthesized magnetite nanoparticles were characterized by Transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffractometer (XRD). TEM results shows that magnetite nanoparticles which were synthesized with ferric/ferrous ratio 2:1 are in sphere shape and have the smallest particle size distribution range which is about 12-17 nm. The particles size distribution range of coated magnetite was decreased to 11-15 nm after coated with 8% surfactant SDS. XPS results indicated that the produced magnetite nanoparticles consisted of elemental iron and oxygen at 72.76% and 22.27% respectively. The phase and face-centered cubic structure of magnetite nanoparticle was also confirmed by XRD. Magnetite nanoparticle synthesized with ferric to ferrous ratio of 2:1 and coated with 8% surfactant SDS shows the best crystallinity among all samples with particle distribution size range from 11-15 nm.
Over the past few decades, extensive research has been conducted to develop cost-effective and high-quality biochar for environmental biodegradation purposes. Pyrolysis has emerged as a promising method for recovering biochar from biomass and waste materials. This study provides an overview of the current state-of-the-art biochar production technology, including the advancements and biochar applications in organic pollutants remediation, particularly wastewater treatment. Substantial progress has been made in biochar production through advanced thermochemical technologies. Moreover, the review underscores the importance of understanding the kinetics of pollutant degradation using biochar to maximize its synergies for potential environmental biodegradation. Finally, the study identifies the technological gaps and outlines future research advancements in biochar production and its applications for environmental biodegradation.
Thermal co-processing of lignocellulosic and aquatic biomass, such as algae and shellfish waste, has shown synergistic effects in producing value-added energy products with higher process efficiency than the traditional method, highlighting the importance of scaling up to pilot-scale operations. This article discusses the design and operation of pilot-scale reactors for torrefaction, pyrolysis, and gasification, as well as the key parameters of co-processing biomass into targeted and improved quality products for use as fuel, agricultural application, and environmental remediation. Techno-economic analysis reveals that end product selling price, market dynamics, government policies, and biomass cost are crucial factors influencing the sustainability of thermal co-processing as a feasible approach to utilize the biomass. Because of its simplicity, pyrolysis allows greater energy recovery, while gasification has the highest net present value (profitability). Integration of liquefaction, hydrothermal, and fermentation pre-treatment technology has the potential to increase energy efficiency while reducing process residues.
Traditional disposal of animal manures and lignocellulosic biomass is restricted by its inefficiency and sluggishness. To advance the carbon management and greenhouse gas mitigation, this review scrutinizes the effect of pyrolysis in promoting the sustainable biomass and manure disposal as well as stimulating the biochar industry development. This review has examined the advancement of pyrolysis of animal manure (AM) and lignocellulosic biomass (LB) in terms of efficiency, cost-effectiveness, and operability. In particular, the applicability of pyrolysis biochar in enhancing the crops yields via soil remediation is highlighted. Through pyrolysis, the heavy metals of animal manures are fixated in the biochar, thereby both soil contamination via leaching and heavy metal uptake by crops are minimized. Pyrolysis biochar is potentially use in soil remediation for agronomic and environmental co-benefits. Fast pyrolysis assures high bio-oil yield and revenue with better return on investment whereas slow pyrolysis has low revenue despite its minimum investment cost because of relatively low selling price of biochar. For future commercialization, both continuous reactors and catalysis can be integrated to pyrolysis to ameliorate the efficiency and economic value of pyrolysis biochar.