With the unique properties such as high surface area to volume ratio, stability, inertness, ease of functionalization, as well as novel optical, electrical, and magnetic behaviors, nanomaterials have a wide range of applications in various fields with the common types including nanotubes, dendrimers, quantum dots, and fullerenes. With the aim of providing useful insights to help future development of efficient and commercially viable technology for large-scale production, this review focused on the science and applications of inorganic and organic nanomaterials, emphasizing on their synthesis, processing, characterization, and applications on different fields. The applications of nanomaterials on imaging, cell and gene delivery, biosensor, cancer treatment, therapy, and others were discussed in depth. Last but not least, the future prospects and challenges in nanoscience and nanotechnology were also explored.
The potential of granular‐activated carbon (GAC) derived from agrowaste of Mangostene (Mangostana garcinia) fruit peel was investigated in batch and fixed bed system as a replacement of current expensive methods for treating wastewater contaminated by manganese, Mn(II) cations. Batch equilibrium data was analyzed by Langmuir, Freundlich, and Temkin isotherm models at different temperatures. The effect of inlet metal ion concentration (50 mg/L, 70 mg/L, and 100 mg/L), feed flow rate (1 mL/min and 3 mL/min), and activated carbon bed height (4.5 cm and 3 cm) on the breakthrough characteristics of the fixed bed sorption system were determined. The adsorption data were fitted with well‐established column models, namely, Thomas, Yoon‐Nelson, and Adams‐Bohart. The results were best‐fitted with Thomas and Yoon‐Nelson models rather than Adams‐Bohart model for all conditions. The column had been regenerated and reused consecutively for five cycles. The results demonstrated that the prepared activated carbon was suitable for removal of Mn(II) ions from wastewater using batch as well as fixed bed sorption system.
Rapid growth in various industrial fields has introduced a series of new environmental risks. The textile industry is one of the major industries that is influenced by rapid advancements in technological sectors. The development in textile dying technologies has presented new types of dyes that are toxic to the ecosystem. Azo dyes are the main artificial dyes used in textiles, food, and other applications. Typically, these dyes are introduced into the environment as wastewater discharged from factories. The discharged influence penetrates the ecosystem and causes deadly diseases to human and animals. Several studies present activated carbon as a proper solution to eliminating the presence of azo dyes in the environment. However, various types of azo dye have different properties and chemical structures. Thus, there is a crucial need for more studies on the application of activated carbons to eliminate the presence of azo dyes in the environment. This paper discusses the toxic effects of azo dyes on the environment and human health. Moreover, this work presents a general review of the preparation of activated carbon and the parameters that influence the adsorption performance.
This research aims to pretreat and activate biochar samples for sorption studies of Mn(II) cations from synthetic wastewater. The bio-char was initially synthesized by physical activation of dried Hibiscus canabilis L stems. The synthesized char was pretreated with a strong metal hydroxide catalyst of potassium hydroxide (KOH). The secondary phase of activation was conducted by using carbon dioxide gas. Batch adsorption was conducted to delineate the effect of agitation time, temperature and initial cation concentration in synthetic solution. Adsorption kinetics were studied by analyzing the experimental data using Pseudo First, Pseudo Second, Elovich and Intra Particle Diffusion Models. Mathematical simulation after linearization of the aforementioned kinetic models showed that the adsorption kinetics was mainly governed by Elovich and pseudo second order kinetics. This indicated that Mn(II) cations were mainly chemically adsorbed by means of complex formation with the active functional groups present on the surface of the pretreated and activated biochar. Langmuir, Freundlich and Temkin isotherm models were used at different temperatures to elucidate the sorption performance of the equilibrium system. The Langmuir maximum monolayer adsorption capacity obtained was 31.25 mg g−1 at 30 °C. Thermodynamic parameters were evaluated. Negative values of Gibb's free energy, ΔG° ensure the feasibility of the equilibrium system. The process was endothermic as the enthalpy change, ΔH° obtained for the process was positive.