Strategies to design modified activated carbon fibers for the decontamination of water and air

The rapid industrialization has induced the entry of organic and inorganic contaminants into the environment at a rate greater than environmental cleaning. As a consequence, pollutants have accumulated in environmental media, thus posing health risk for living organisms. Here, we present surface treatment strategies that modify physicochemical properties of activated carbon fibers for environmental remediation. In particular, we review metals, metal oxides and various advanced materials used for modifying activated carbon fibers. We discuss the utilization of modified activated carbon fibers for adsorption of organic pollutants and inorganic pollutants, and for the degradation of organic pollutants by photocatalysis, electrocatalysis, Fenton process and dielectric barrier discharge. We also discuss air pollutant removal, capacitive deionization, removal of inorganic ions and microbial decontamination by modified activated carbon fibers.     

Activated carbon from industrial solid waste as an adsorbent for the removal of Rhodamine-B from aqueous solution: kinetic and equilibrium studies

The activated carbon was prepared using industrial solid waste called sago waste and physico-chemical properties of carbon were carried out to explore adsorption process. The effectiveness of carbon prepared from sago waste in adsorbing Rhodamine-B from aqueous solution has been studied as a function of agitation time, adsorbent dosage, initial dye concentration, pH and desorption. Adsorption equilibrium studies were carried out in order to optimize the experimental conditions. The adsorption of Rhodamine-B onto carbon followed second order kinetic model. Adsorption data were modeled using both Langmuir and Freundlich classical adsorption isotherms. The adsorption capacity Q0 was 16.12 mg g(-1) at initial pH 5.7 for the particle size 125-250 microm. The equilibrium time was found to be 150 min for 10, 20 mg l(-1) and 210 min for 30, 40 mg l(-1) dye concentrations, respectively. A maximum removal of 91% was obtained at natural pH 5.7 for an adsorbent dose of 100mg/50 ml of 10 mg l(-1) dye concentration and 100% removal was obtained when the pH was increased to 7 for an adsorbent dose of 275 mg/50 ml of 20 mg l(-1) dye concentration. Desorption studies were carried out in water medium by varying the pH from 2 to 10. Desorption studies were performed with dilute HCl and show that ion exchange is predominant dye adsorption mechanism. This adsorbent was found to be both effective and economically viable.     

Orange peel as an adsorbent in the removal of acid violet 17 (acid dye) from aqueous solutions

The effectiveness of orange peel in adsorbing Acid violet 17 from aqueous solutions has been studied as a function of agitation time, adsorbent dosage, initial dye concentration and pH. The adsorption follows both Langmuir and Freundlich isotherms. The adsorption capacity Q0 was 19.88 mg/g at initial pH 6.3. The equilibrium time was found to be 80 min for 10, 20, 30 and 40 mg/L, dye concentration respectively. A maximum removal of 87% was obtained at pH 2.0 for an adsorbent dose of 600 mg/50 ml of 10 mg/L dye concentration. Adsorption increases with increase in pH. Maximum desorption of 60% was achieved in water medium at pH 10.0.     

Photocatalytic degradation of atrazine in aqueous solution using La-doped ZnO/PAN nanofibers

Environmental Science and Pollution Research - Polyacrylonitrile (PAN)-based-modified zinc oxide (ZnO) nanofibers were synthesized by using electrospinning and hydrothermal techniques. The...