Effective Removal of Chromium(III) from Low Concentration Aqueous Solution Using a Novel Diazene/Methoxy-Laced Coordination Polymer.

Lei-Lei Liu,Cai-Xia Yu,Ming-Zhen Miao,Meng-Qi Ye,Cai-Wen Zhang,Hui-Ying Yu,Yun Xing

doi:10.3390/polym9070273

Lei-Lei Liu, Cai-Xia Yu + Show 5 more

Open Access

https://doi.org/10.3390/polym9070273

Copy DOI

Journal: Polymers	Publication Date: Jul 9, 2017
Citations: 9	License type: CC BY 4.0

Affiliation: Anyang Normal University

Abstract

In this study, a novel coordination polymer [CdL2(H2O)0.5]n (1), [HL = 4-(2-(4-((pyridin-3-yl)methoxy)phenyl)diazenyl)benzoic acid] was fabricated via an in situ ligand transformation reaction under solvothermal conditions. The as-prepared polymer exhibited a selectivity and efficiency for Cr(III) removal with a high uptake capacity of 106.13 mg·g−1. Interestingly, even in the low concentration (0.02–0.20 ppm), it still performs a relatively high efficiency (≥ 92.5%) towards the removal of Cr(III) in aqueous solution. Remarkably, it also presents good selectivity and high efficiency (93.3%) for Cr(III) removal in the presences of interfering metal ions. The good removal performance for Cr(III) was demonstrated to be a structure-dependent chemical process between polymer and Cr(III) involving the diazene and methoxy groups in polymer 1, which happened not only on the surfaces of the adsorbent but also in the pores of polymer, giving rise to a strong affinity toward Cr(III) adsorption. The possible adsorption mechanism of Cr(III) was proposed and systematically verified by FT-IR, scanning electron microscope (SEM), atomic force microscope (AFM) and energy dispersive spectrometer (EDS) measurements.

Highlights

Heavy metal pollution has become a serious threat to environment and public health, since they are highly toxic and accumulate throughout the food chain [1,2]
Trace amounts of chromium are required for biological functions, excess is reported to cause health-related problems like rashes, ulcers, respiratory disorders, cardiovascular diseases and weakening of immune systems [4,5]
As shown in Scheme 1, L1 ligand contains two rigid benzene ring pieces and two freely rotating pyridyl arms combined by intervening methoxy, diazene, carbomethoxy groups

Summary

Introduction

Heavy metal pollution has become a serious threat to environment and public health, since they are highly toxic and accumulate throughout the food chain [1,2]. Chromium is a prevalent and highly reactive pollutant which dissipates into the ecosystems from a variety of industrial activities such as electroplating, leather tanning, mining, textile dyeing, wood preserving, chromate preparation and metal finishing [3]. Trace amounts of chromium are required for biological functions, excess is reported to cause health-related problems like rashes, ulcers, respiratory disorders, cardiovascular diseases and weakening of immune systems [4,5]. Trivalent chromium [Cr(III)] [6]. Out of the two states, Cr(VI) is generally considered as more toxic because of its ability to cross cellular membranes and its strong oxidizing power [7].

Methods

Results

Conclusion