Arsenic, one of the most toxic and dangerous elements in the environment affecting millions of people around the world, is associated with several diseases. In this pilot study, we investigated removal of arsenate from aqueous solutions using chitosan under the influences of initial arsenic ion concentrations, pH, contact time, and adsorbent dosages of chitosan. In order to assess the sorption ...

The present study aims at investigating the potential of activated carbon AC prepared from waste cotton fiber for the removal of Acid Dyes from aqueous solutions. The prepared activated carbon was characterized by pore structure analysis, Fourier transforms infrared spectroscopy FTIR. Batch adsorption studies were carried out and the effect of experimental parameters such as pH, initial dye con...

We consider the restriction of first–order logic to models, called pseudo– finite, with the property that every first–order sentence true in the model is true in a finite model. We argue that this is a good framework for studying first-order logic on finite structures. We prove a Lindström Theorem for extensions of first order logic on pseudo-finite structures.

Abstract If dark matter (DM) acquires mass during a first order phase transition, there will be filtering-out effect when DM enters the expanding bubble. In this paper we study for pseudo-scalar DM, whose may partially come from transition in hidden sector. We calculate ratio of that enter bubble various wall velocities as well status (in thermal equilibrium, or out equilibrium) at time which r...

We consider expected risk minimization problems when the range of estimator is required to be nonnegative, motivated by settings maximum likelihood estimation (MLE) and trajectory optimization. To facilitate nonlinear interpolation, we hypothesize that search space a Reproducing Kernel Hilbert Space (RKHS). develop first second-order variants stochastic mirror descent employing (i) \emph{pseudo...

the kinetic study of methylene blue (mb) adsorption using acid-activated spent tea (aast) as an adsorbent from aqueous solution with the aim of comparing linear and non-linear regression analysis methods was performed at varying initial mb concentrations (10-100 mg/l). hence, spent tea leaves, which were activated using concentrated sulfuric acid, were prepared. the physicochemical characterist...

the removal of as(iii) ions from aqueous solutions has been investigated using silica ceramic under different experimental conditions of initial arsenite concentration, adsorbent dose, temperature and ph. better removal was obtained at temperature 25âºc and ph 7.5. the adsorption data have been explained in terms of langmuir and freundlich equations. the sorption kinetics was tested for the pse...

background dyes are one of the most important industrial pollutants, especially in textile industries. many methods have been proposed in order to remove color from wastewater among which, adsorption is more acceptable due to the ability for its use in the large scale. objectives the objective of this study was to investigate pumice as an inexpensive adsorbent for removal of methylene blue from...