This work evaluated the use of Dialium guineense seed waste (DGS) and its sodium hydroxide modified form (NH-DGS) as biosorbent for ciprofloxacin (CPF) from synthetic solution as well as the desorption potentials. Central composite design (CCD) was applied for optimization of the alkaline treated biosorbent by response surface methodology using design expert. Both biosorbents were characterized by FTIR, SEM, EDX, and BET analysis. The CCD showed NaOH concentration of 0.46 M and temperature of 96 °C to be effective for optimized modification of NH-DGS. Optimum removal of CPF was obtained at pH 6.0, contact time 120 min, temperature 300 K, and dosage of 0.1 g. The Freundlich model gave the best fit compared to the other isotherms tested with R2 values >0.97951. NH-DGS exhibited a maximum uptake capacity of 120.34 mg/g higher than some reported adsorbents for CPF. The pseudo-second-order model was suitable in the fitting of the kinetic data. A non-spontaneous process was obtained for CPF biosorption on DGS which became spontaneous after alkaline treatment. Over 84% desorption of CPF was achieved on both biosorbents using 0.3 M HCl which envisaged the use of NH-DGS as an efficient material for treatment of waters contaminated with CPF.
14 July 2020 in Arabian Journal for Science and Engineering
This novel study investigated and proposes the use of Pycnanthus angolensis seed husk for the sequestration of Pb(II) from contaminated solutions, with the aim of contributing to the urgent need for accessibility to quality water, sustainable management of water and the environment in line with the Sustainable Development Goals (SDGs). The activated Pycnanthus angolensis seed husk was developed by modifying the pure sample (P-PA) with ethylene-glycol (E-PA) and Iso-butanol (I-PA). Infrared spectroscopy (FTIR), scanning electron microscopy (SEM), the Brunauer-Emmett-Teller (BET) analyzer, thermogravimetric analyzer (TGA), and X-ray diffractometer (XRD) were used to characterize the adsorbents before and after adsorption. The batch adsorption studies carried out revealed the highest adsorption of Pb(II) at pH 6 and 180 min for all the adsorbents. The functional groups, as well as the shifts in peaks after modification, were confirmed using FTIR analysis. In addition, SEM images show a heterogeneous, rough surface with sufficient cavities of the adsorbent after modification. The physiochemical characteristics indicated that BET pore volume and pore diameter increased for E-PA and I-PA compared to P-PA. The experimental data obtained indicated that Langmuir and pseudo-first-order (PFO) best described the isotherm and kinetic models, respectively. The adsorption mechanism revealed that the adsorption of Pb(II) was controlled mainly by pore filling, while electrostatic interaction, surface complexation, and ionic exchange also occurred minimally. The thermodynamic parameters, ΔH° and ΔG°, suggest an endothermic and spontaneous adsorption process, respectively. The findings in this study indicate that Pycnanthus angolensis seed husks offer cost-effective and sustainable solutions that are readily accessible for wastewater treatment.
19 November 2018 in Petroleum Science and Technology
Codiaeum variegatum stem powder (CVSP) was used as a low cost, readily available and biodegradable sorbent for decontamination of crude oil from aqueous solution. CVSP was characterized by the FTIR, SEM and BET techniques. The physical characterization of the crude oil showed light crude. Equilibrium isotherm of crude oil uptake was analyzed by the Langmuir, Feundlich, Tempkin, Flory-Huggins and Scatchard models. The Langmuir isotherm gave best fit with regression of 0.995 indicating a homogenous CVSP surface involving monolayer sorption of crude oil, supported by the Scatchard model analysis. The maximum monolayer uptake capacity of CVSP for crude oil was established and compared to other reported sorbents.
This study examines the diverse impacts of ionizing radiation exposure, focusing on health, economic, and social consequences. It highlights the current regulatory framework for radiation safety, along with recent efforts aimed at strengthening it. Exposure to ionizing radiation can result in adverse public health effects, including cognitive decline, psychological stress, and substantial economic costs related to medical treatment and environmental remediation. The regulatory authorities play a central role in managing radiation safety; however, they face significant challenges such as limited resources, inadequate infrastructure, and a pressing need for public awareness. Recent improvements in these regulations include the revision of safety protocols, partnerships with international bodies, and the implementation of advanced monitoring technologies. Notable radiation incidents include a gamma irradiator mishap, the theft of radioactive sources, cases of medical radiation overexposure, scrap metal contamination, and the improper disposal of radioactive materials. These events underscore the critical need for effective radiation management and regulation. Continued efforts to enhance radiation safety emphasize updating safety measures, international collaboration, and investment in education and research. This study provides a comprehensive perspective on the challenges and opportunities associated with ionizing radiation, stressing the vital role of robust regulatory practices in safeguarding public health and the environment.
25 September 2018 in Biosciences Biotechnology Research Asia
The biosorption of Cd (II), As (III) and Pb (II) ions from solution utilizing Vigna unguiculata leaf powders (VULP) as a low cost biosorbent was studied. The influence of temperature, metal ion concentration, biosorbent dose, contact time and pH on the sequestration process was examined by batch procedure. Increase in the biosorption of the three metal ions with increased pH and biosorbent dosage was obtained in this study.Equilibrium contact time of 20, 40 and 50min was achieved for Cd(II), As (III) and Pb(II) ions and biosorption was in the order As(III)> Cd(II) >Pb(II). Isotherm analysis was performed by the application of Langmuir, Freundlich, Flory-Huggins and Scatchard models. The Langmuir model gave the best fit with maximum monolayer biosorption capacity of 109.1, 105 and 119.3 mg/g for Cd (II), Pb (II) and As (III) respectively. Scatchard model confirmed a homogenous surface of VULP and monolayer biosorption of metal ions. Pseudo second order model showed the best fit compared to pseudo first order, Elovich and Banghams kinetic models according to kinetic analysis. Thermodynamics study revealed a feasibly, spontaneous exothermic biosorption process. The result showed good potentials of VULP as suitable cheap biosorbent for attenuation of Cd (II), Pb(II) and As (III) ions from polluted wastewaters.