Biosorption Behaviour of an Arid Land Plant, Euphorbia Rigida, Towards to Heavy Metals: Equilibrium, Kinetic and Thermodynamic Studies

T he potential of an arid-land plant, Euphorbia rigida E. rigida , for the removal of heavy metals [Pb II , Zn II , Cu II , Cd II , Ni II ] from aqueous solutions was studied in the current work. Batch sorption experiments were conducted to investigate the effects of pH, particle size, initial metal ion concentration, contact time and temperature. Besides, biosorption data was analysed by different isotherm and kinetic models. Equilibrium studies showed that the biosorption closely follows the Langmuir and Freundlich isotherms. From the kinetic point of view, pseudo-second order model gave the best fitting with the experimental results. The evaluated thermodynamic parameters showed that biosorption onto E. rigida was a feasible, spontaneous and endothermic process. The affinities of metal ions onto E. rigida decreased as Pb II > Zn II > Cd II > Cu II > Ni II in single metal biosorption. Besides, binary and ternary metal sorption studies were conducted to investigate the co-ion effect. Experimental results showed that E. rigida can be used as an alternative and effective low cost biosorbent for the removal of heavy metals from aqueous solution

Comparative analysis of hemosorbents obtained at different modes

When using hemosorbent laminar flow, a large active area of sorbents is used, the trauma of the blood corpuscles decreases dramatically, the ash content of the saline solution is absent. One of the methods of solving environmental problems is to develop various materials based on industrial waste. In the article, the method of obtaining carbonized rice husks is described, the adsorption capacity for methylene blue was measured for the obtained sample, the morphological structure was examined, comparative analysis with analogs was carried out. The authors carried out research work, such as collecting information, selecting methods, conducting analysis, processing the results. Granular hemosorbents that have been used until recently penetrate the blood-forming elements, creating a mechanism for thrombosis that violates the integrity of the erythrocyte membrane. The experimental part of the research work on the effectiveness of next generation chemosorbents confirmed the apparent achievement of results and the rejection of new capabilities in a clinical approach to extracorporeal detoxifying modes of use and chemosorption by possession. The use of chemosorption as the main therapeutic option for headache disorders due to liver and kidney pathology has been identified in cases where other conditions are unsuccessful or ineffective. However, the use of fixed cost chemosorption in terms of treatment for patients remains unclear. The presence of chemical, hemodynamic, electrolytic, hormonal, immunological disorders prevents the prevalence of existing use in extracorporeal chemisorption.Keywords: adsorption, carbonization, detoxication, hemosorbents, sorbent.

Potential of pyrolysis processes in the waste management sector

The fundamentals of pyrolysis, its latest developments, the different conditions of the process and its residues are of great importance in evaluating the applicability of the pyrolysis process within the waste management sector and in waste treatment. In particular the types of residue and their further use or treatment is of extreme interest as they could become the source of secondary raw materials or be used for energy generation in waste treatments. The main area of focus of this paper is the investigation of the link between the pyrolysis conditions, the chemical and mineralogical composition of their products and the benefits of pyrolysis in the waste management sector. More specifically the paper covers the fast, intermediate and slow pyrolysis of organic waste and mixtures of inorganic and organic waste from households. The influence of catalysts during fast pyrolysis on the product yield and composition is not being considered in this review.This reported work was conducted as part of the “Design Optimisation of the HERU Waste Treatment System” project in Brunel University London that was funded by Manik Ventures Limited

Pyrolysis kinetics and thermal decomposition behavior of polycarbonate - a TGA-FTIR study

This study covers the thermal degradation of polycarbonate by means of Thermogravimetric Analyzer coupled with Fourier transform infrared spectrometer (TGA-FTIR). Thermogravimetric analysis of polycarbonate was carried out at four different heating rates of 5, 10, 15, and 20°C per minute from 25°C to 1000°C under nitrogen atmosphere. The results indicated that polycarbonate was decomposed in the temperature range of 425-600°C. The kinetic parameters, such as activation energy, pre-exponential factor and reaction order were determined using five different kinetic models; namely Coast-Redfern, Friedman, Kissinger, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS). Overall decomposition reaction order was determined by Coats-Redfern method as 1.5. Average activation energy was calculated as 150.42, 230.76, 216.97, and 218.56 kJ/mol by using Kissinger, Friedman, FWO, and KAS models, respectively. Furthermore, the main gases released during the pyrolysis of polycarbonate were determined as CO2, CH4, CO, H2O, and other lower molecular weight hydrocarbons such as aldehydes, ketones and carbonyls by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometer