A novel route to the engineering of zirconium immobilized nano-scale carbon for arsenate removal from water

Abstract

Carbon nanoparticles often contain several tunable functional groups on the surface that bring about many interesting and unique properties. In this study, a novel class of hydrophilic carbons on a nanometer scale was prepared from waste biomass with hydroxyl groups on the surface. Electron microscopic studies showed that the prepared carbon particles have sizes of 50-70 nm. Raman spectroscopy revealed that these particles were amorphous in nature with no aromatization. Zirconium(IV) was then chemically immobilized to the hydroxyl group of the carbon under basic conditions. It was found that zirconium (Zr) ions were successfully bound onto the nano-scale carbons (NSC). The toxicity of the Zr-immobilized NS carbon (ZNC) was investigated using breast cancer stem cells (MCF7); no cytotoxic effects on the cells were found after 5 days of incubation. The nano-scaled adsorbent was used for the adsorption of arsenic. It was found that 70 to 75% of its final adsorption was achieved within the first 10 min, much faster than many other adsorbents. The high oxophilicity of Zr(IV) ions results in the fast adsorption of arsenate anions. The Langmuir equation well described the adsorption isotherm; the maximum adsorption capacity was around 110 mg g À1 at the optimal pH. The commonly existing anions such as fluoride, phosphate and nitrate as well as humic acid had no significant effects on the uptake. However, silicate ions had a large influence on the adsorption. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopic analysis revealed that the negatively charged arsenate forms chemical linkages with the ZNCs (via the electropositive metal (Zr 4+) precursor). From this study it was concluded that adsorption by ZNC would be a better solution for arsenic contaminated surface and groundwater.

Superior removal of arsenic from water with zirconium metal-organic framework UiO-66

“…Compared to previously reported adsorbents shown in Table 2 and Fig. 4(b) , the UiO-66 adsorbent delivers the best arsenic adsorption capacity, much higher than that of commercial adsorbents (approximately 50 mg/g) 7 8 and synthetic adsorbents (5–280 mg/g, generally less than 100 mg/g) 6 9 10 15 16 30 31 32 33 34 48 49 50 . Most prevalent adsorbents can seldom achieve 100 mg/g even at optimal pH.…”

“…Since zirconium based adsorbents such as amorphous zirconium oxide nanoparticles 33 and zirconium immobilized nano-scale carbon 34 demonstrated strong affinity towards arsenic species, a porous crystalline material containing zirconium, which provides a larger contact area and more active adsorption site, may deliver a better arsenic uptake performance. Recently, a series of zirconium MOFs (Zr-MOFs) with exceptional chemical and thermal stability has emerged 35 36 37 38 39 40 .…”

Arsenate removal from contaminated water by a highly adsorptive nanocomposite ultrafiltration membrane

“…3 Therefore, in order to minimize these health risks, in January 2001, the US Environmental Protection Agency (EPA) has set the As standard for drinking water, aiming to reduce As concentration to 10 mg L À1 by 2006. [6][7][8][9][10][11][12][13] However, to efficiently decrease As concentration to acceptable levels as required by the law, all the above mentioned technologies experience or be subjected to one or more drawbacks, restrictions and practicability. [6][7][8][9][10][11][12][13] However, to efficiently decrease As concentration to acceptable levels as required by the law, all the above mentioned technologies experience or be subjected to one or more drawbacks, restrictions and practicability.…”

A new one‐dimensional coordination polymer synthesized from zinc and guanazole: Superior capture of organic arsenics

“…[ 62–64 ] The small peak at 656 cm −1 (after adsorption of p ‐ASA and ROX) might be attributed to the asymmetric stretching of As–OH. [ 65 ] The elemental mapping results (Figure 10) confirmed the presence of arsenic on BUC‐70 after the adsorption test.…”