Performance of a New Magnetic Chitosan Nanoparticle to Remove Arsenic and Its Separation from Water

Cheng Liu,Si-Yuan He,Wei Chen,Jie Wang,Bin Wang,Yang Deng,Biao Cui

doi:10.1155/2015/191829

Cheng Liu, Si-Yuan He + Show 5 more

Open Access

https://doi.org/10.1155/2015/191829

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Abstract

Removal performance of arsenic in water by a novel magnetic chitosan nanoparticle (MCNP) with a diameter of about 10 nm, including adsorption kinetics, adsorption isotherm, main influencing factors, and regeneration effects, was investigated. In addition, the effective separation way for MCNP particles and the new application mode were developed to prompt the application of MCNP. The results showed that MCNP exhibited excellent ability to remove As(V) and As(III) from water in a wide range of initial concentrations, MCNP removed arsenic rapidly with more than 95% of arsenic adsorbed in initial 15 min, and the whole process fitted well to the pseudo-second-order model. The Langmuir model fits the equilibrium data better than the Freundlich isotherm model and the maximum adsorption capacities of As(V) and As(III) were 65.5 mg/g and 60.2 mg/g, respectively. The saturated MCNP could be easily regenerated and kept more than 95% of initial adsorption capacity stable after 10 regeneration cycles. A new magnetic material separation method was established to separate MCNP effectively. The continuous-operation instrument developed based on the MCNP could operate stably and guarantee that the concentration of arsenic meets the guideline limit of arsenic in drinking water regulated by the WHO.

Highlights

Arsenic has been found in the groundwater in many regions of the world such as Bangladesh [1], India [2], and other countries [3]
Chitosan is a poly-N-glucosamine species obtained by the deacetylation of chitin, the most abundant aminopolysaccharide existing in the environment
Because the magnetic chitosan nanoparticle (MCNP) had little pores, the adsorption process may consist of two processes: (1) the transport of arsenic from bulk solution to the surface of MCNP and (2) the attachment of arsenic to MCNP

Summary

Introduction

Arsenic has been found in the groundwater in many regions of the world such as Bangladesh [1], India [2], and other countries [3]. Just like precipitation [8], membrane separation, ion exchange, and adsorption [9,10,11], have been applied to remove excessive arsenic from water. Chitosan is a poly-N-glucosamine species obtained by the deacetylation of chitin, the most abundant aminopolysaccharide existing in the environment It is highly hydrophilic and is characterized by a flexible polymer chain and by a large number of hydroxyl and amino groups that represent potential adsorption sites. A novel magnetic chitosan nanoparticle (MCNP) was prepared by one-step in situ coprecipitation at low temperature and normal atmosphere, which showed significant adsorption potential for the removal of humic acid (HA) from aqueous solution [20, 21], but the removal performance for arsenic and subsequent separation have not been examined. Items As (mg/L) F (mg/L) Cl (mg/L) SO42− (mg/L) Hg (mg/L) Pb (mg/L) Mn (mg/L) Fe (mg/L) Cu (mg/L) Na (mg/L) Ca (mg/L) Mg (mg/L) Total hardness (mg/LCaCO3) UV254 (cm−1) pH DOC (mg/L)

Material and Methods

Performance of MCNP to Remove Arsenic from Water

25 Water after iron filter

Conclusion