Ahmed Mosa

Bio: Ahmed Mosa is an academic researcher from Mansoura University. The author has contributed to research in topics: Biochar & Sorption. The author has an hindex of 19, co-authored 40 publications receiving 1884 citations. Previous affiliations of Ahmed Mosa include University of Florida.

A review of biochar as a low-cost adsorbent for aqueous heavy metal removal

Abstract: As a low-cost adsorbent, biochar can be used as a low-cost adsorbent for wastewater treatment, particularly with respect to treating heavy metals in wastewater. A number of studies have demonstrated effective removal of heavy metals from aqueous solutions by biochar and, in some cases, proven the superiority of biochars to activated carbons. Among several factors affecting the sorption ability of biochars, feedstock materials play a significant role. This review incorporates existing literature to understand the overall sorption behavior of heavy metals on biochar adsorbents. Depending on the biochar type, heavy metal can be removed by different mechanisms such as complexation, physical sorption, precipitation and electrostatic interactions. Mathematical sorption models can be used to understand the efficiency of biochar at removing heavy metals, and promote the application of biochar technology in water treatment.

Sorption of heavy metal ions onto crayfish shell biochar: Effect of pyrolysis temperature, pH and ionic strength

Abstract: In this study, crayfish shell was pyrolyzed at 300 (CS300), 450 (CS450) and 600 °C (CS600) to identify the optimum temperature for improving the binding capacity of the produced biochar. The removal efficiency of biochars was assessed following mono-element sorption of Pb(II) under batch sorption and fixed-bed column experiments. The effect of pH and ionic strength on Pb(II) sorption was further investigated on the most efficient biochar type to understand environmental factors affecting sorption onto crayfish biochar. Besides, this most efficient biochar was further investigated in multi-element sorption (Pb(II), Cu(II) and As(III)) trial to assess the effect of competitive sorption on Pb(II) bioavailability. Pyrolysis temperature had different effects on elemental composition, surface area and active functional groups of the produced biochar. CS600 showed the highest sorption capacity (190.7 mg/g) of Pb(II). Sorption mechanisms were identified following FTIR, SEM, XRD and ICP analyses suggested the participation of physisorption. Sorption of Pb(II) onto crayfish biochar was strongly pH- and ionic strength-dependent as the sorption capacity showed significant reductions at low pH and high ionic strength values. The competitive sorption of Pb(II) with other metal ions (Cu(II) and As(III)) showed its superiority to bind with active sorption sites of biochar as compared with other heavy metals.

Pharmaceuticals of Emerging Concern in Aquatic Systems: Chemistry, Occurrence, Effects, and Removal Methods.

Abstract: In the last few decades, pharmaceuticals, credited with saving millions of lives, have emerged as a new class of environmental contaminant. These compounds can have both chronic and acute harmful effects on natural flora and fauna. The presence of pharmaceutical contaminants in ground waters, surface waters (lakes, rivers, and streams), sea water, wastewater treatment plants (influents and effluents), soils, and sludges has been well doccumented. A range of methods including oxidation, photolysis, UV-degradation, nanofiltration, reverse osmosis, and adsorption has been used for their remediation from aqueous systems. Many methods have been commercially limited by toxic sludge generation, incomplete removal, high capital and operating costs, and the need for skilled operating and maintenance personnel. Adsorption technologies are a low-cost alternative, easily used in developing countries where there is a dearth of advanced technologies, skilled personnel, and available capital, and adsorption appears to be the most broadly feasible pharmaceutical removal method. Adsorption remediation methods are easily integrated with wastewater treatment plants (WWTPs). Herein, we have reviewed the literature (1990-2018) illustrating the rising environmental pharmaceutical contamination concerns as well as remediation efforts emphasizing adsorption.