The removal of diazinon from aqueous solution by chitosan/carbon nanotube adsorbent

Abstract

a b s t r a c tThe removal of diazinon using low-cost sorbent Chitosan/Carbon Nanotube (CHN-CNT) from aqueous solutions has been investigated in the present study. A protected cross linking method was used to synthesis of CHN-CNT with 2.5% of MWCNT. MWCNT is a promising candidate for improving chitosan mechanical properties. Scanning electron microscopy (SEM), infrared spectroscopy (FT-IR) and Thermogravimetric analyzer (TGA) were used to characterize the prepared adsorbent. Tests were done to evaluate the effects of solution pH, the amount of CHN-CNT, diazinon concentration, contact time and solution temperature on adsorption of diazinon onto CHN-CNT. Results showed that CHN-CNT at a low amount of 0.5 g/L, in contact time 60 min and pH 5.5, could remove 82.5% of the diazinon at initial concentration 5 mg/L. The Langmuir, Freundlich and Sips isotherm models were used to analyze the equilibrium experimental data. Equilibrium adsorption isotherm data exhibited better fit to the Sips isotherm model, where the heterogeneity factor (n = 0.66) indicated heterogeneous adsorption characteristics, with a maximum adsorption capacity of 222.86 mg/g. Also the experimental adsorption data was fitted well to the pseudo-second-order model. Overall, the use of CHN-CNT due to the easier to prepare, high performance in adsorption, simple and effective regeneration make CHN-CNT as a promising adsorbent to eliminate the pesticide from contaminated streams.

A review of the adsorption method for norfloxacin reduction from aqueous media

“…An adsorbent can be recovered by using an eluent to remove the NRFX from its surface. The percentage difference between the regenerated adsorbents' and the initial adsorbent's adsorption capacity is known as the adsorbent recovery [ 172 , 173 ]. This is especially significant because it reduces the cost of the process.…”

Recent Developments in Chitosan-Based Adsorbents for the Removal of Pollutants from Aqueous Environments

“…Similar to that employed in the formation of CS/GO, the CS/CNTs are formed by initially dissolving the chitosan in acetic acid, then the CNTs are added, dispersed and normally a crosslinking agent, such as glutaraldehyde [215], is used. These CS/CNT composites have been employed as adsorbents and used in the removal of Cr(VI) [234], V(V), Cr(VI), Cu(II), As(V) and Ag(I) from biological and environmental samples [235], Cu(II) [236], U(VI) [237], Pb(II) [238], phosphate [239], phenol [60], fluoride [58], diazinon [240], food dyes [241] and dyes [242].…”

Graphene-Based Materials Immobilized within Chitosan: Applications as Adsorbents for the Removal of Aquatic Pollutants

“…It has very good chemical stability combined with chelating properties [98]. Indeed, chitosan has been employed as an effective adsorbent for the removal of dyes [99], phenol [100], heavy metal ions [101], antibiotics [102] and pesticides [103] from water. It is an effective adsorbent as it has a high surface area and possesses a large density of hydroxyl (-OH) and primary amine (-NH 2 ) groups, as illustrated in Figure 2.…”