Adsorption of Lead from Aqueous Solution onto Untreated Orange Barks: Equilibrium, Kinetics and Thermodynamics

Adsorption can be used as a cost effective and efficient technique for the removal of toxic heavy metals from wastewater. Waste materials with no further treatment such as orange barks from commercial oranges may act as adsorbent for the removal of lead. Batch kinetic and equilibrium experiments were conducted to study the effects of contact time, adsorbent dose, initial pH, particle size, initial concentration of lead and temperature. Three adsorption isotherm models namely, Langmuir, Freundlich and Dubinin-Radushkevich were used to analyse the equilibrium data. The Langmuir isotherm which provided the best correlation for Pb2+ adsorption onto orange barks shows that the adsorption was favourable and the maximum adsorption capacity found was equal to 112.359 mg.g-1. Thermodynamic parameters were evaluated and the adsorption was exothermic. The equilibrium was achieved less than 30 min. The adsorption kinetic data was fitted with first and second order kinetic models. Finally it was concluded that the lead adsorption kinetic onto orange barks was well fitted by second order kinetic model rather than first order model. The results suggest that orange barks have high possibility to be used as effective and economical adsorbent for Pb2+ removal

Safety and Dose Study of Targeted Lung Denervation in Moderate/Severe COPD Patients

RATIONALE: Targeted lung denervation (TLD) is a novel bronchoscopic treatment for the disruption of parasympathetic innervation of the lungs. OBJECTIVES: To assess safety, feasibility, and dosing of TLD in patients with moderate to severe COPD using a novel device design. METHODS: Thirty patients with COPD (forced expiratory volume in 1 s 30-60%) were 1:1 randomized in a double-blinded fashion to receive TLD with either 29 or 32 W. Primary endpoint was the rate of TLD-associated adverse airway effects that required treatment through 3 months. Assessments of lung function, quality of life, dyspnea, and exercise capacity were performed at baseline and 1-year follow-up. An additional 16 patients were enrolled in an open-label confirmation phase study to confirm safety improvements after procedural enhancements following gastrointestinal adverse events during the randomized part of the trial. RESULTS: Procedural success, defined as device success without an in-hospital serious adverse event, was 96.7% (29/30). The rate of TLD-associated adverse airway effects requiring intervention was 3/15 in the 32 W versus 1/15 in the 29 W group, p = 0.6. Five patients early in the randomized phase experienced serious gastric events. The study was stopped and procedural changes made that reduced both gastrointestinal and airway events in the subsequent phase of the randomized trial and follow-up confirmation study. Improvements in lung function and quality of life were observed compared to baseline values for both doses but were not statistically different. CONCLUSIONS: The results demonstrate acceptable safety and feasibility of TLD in patients with COPD, with improvements in adverse event rates after procedural enhancements.status: publishe