Data of furfural adsorption on nano zero valent iron (NZVI) synthesized from Nettle extract

Among various water and wastewater treatment methods, adsorption techniques are widely used to remove certain classes of pollutants due to its unique features. Thus, the aim of this data article is to synthesize zero valent iron nanoparticles (NZVI) from Nettle leaf extract by green synthesis method as an environmentally friendly technique, and to evaluate it's efficiency in the removal of furfural from aqueous solutions. The data of possible adsorption mechanism and isotherm of furfural on the synthesized adsorbent are depicted in this data article. The data acquired showed that the adsorption trend follows the pseudo-second order kinetic model and that the Langmuir isotherm was suitable for correlation of equilibrium data with the maximum adsorption capacity of 454.4 mg/g. The information of initial furfural concentration, pH, adsorbent dosage and contact time effects on the removal efficiency are presented. Considering the findings data, the developed nanoparticle from Nettle leaf extract, as a low cost adsorbent, could be considered as promising adsorbent for furfural and probably similar organic pollutants removal from aqueous solutions.


a b s t r a c t
Among various water and wastewater treatment methods, adsorption techniques are widely used to remove certain classes of pollutants due to its unique features. Thus, the aim of this data article is to synthesize zero valent iron nanoparticles (NZVI) from Nettle leaf extract by green synthesis method as an environmentally friendly technique, and to evaluate it's efficiency in the removal of furfural from aqueous solutions. The data of possible adsorption mechanism and isotherm of furfural on the synthesized adsorbent are depicted in this data article. The data acquired showed that the adsorption trend follows the pseudo-second order kinetic model and that the Langmuir isotherm was suitable for correlation of equilibrium data with the maximum adsorption capacity of 454.4 mg/g. The information of initial furfural concentration, pH, adsorbent dosage and contact time effects on the removal efficiency are presented. Considering the findings data, the developed nanoparticle from Nettle leaf extract, as a low cost adsorbent, could be considered as promising adsorbent for furfural and probably similar organic pollutants removal from aqueous solutions.
& The removal of furfural from aqueous solution was examined using a synthesized novel green adsorbent.
Data show that the developed adsorbent has high potential for the removal of furfural from aqueous solution.

Data
The Nettle leaf, as an abundant local plants in Ardabil province, northwestern Iran, used in this study to prepare zero-valent iron nanoparticles (NZVI). Transmission electron microscopy (TEM), and Philips X'Pert Pro instrument (the Netherlands) were used to get particle sizes and XRD patterns of the synthesized nanoparticles, respectively. The obtained data are shown in Fig. 1(a) and (b). The effects of contact time and solution pH on removal efficiency data are presented in Figs. 2 and 3. The kinetic and isotherm data are also shown in Tables 1 and 2.

Materials
All chemicals used in the experiments were high purity analytical grade and purchased from Merck Co. Germany, and are used without further treatment. Aqueous solutions of furfural with desired concentration for the batch experiments were prepared by serial dilution of a 1% stock furfural solution [3].

Green synthesis of NZVI from Nettle extracts
Nettle leaves was purchased from local market and washed several times with double deionized water to remove any dust and dried. Briefly, 60 g/L of the leaves of the plant was boiled at 80°C for 1 h. After about 1 h stagnant time to precipitate the extract, the supernatant was filtered by a vacuum pump. 0.1 M FeCl 2 .4H 2 O solution was prepared by adding 19.9 g of solid FeCl 2 .4H 2 O into 1 l of deionized water. This solution was then added into the filtered supernatant that prepared in previous step in the ratio 2:3 [4]. At this time, a black colored precipitate was appeared which show the formation of NNZVI. The formed nanoparticles were then separated by evaporation on a hot plate surface and collected by washing several times with deionized water and placed in nitrogen gas to avoid oxidation and regarded as NNZVI [5] and used as adsorbent in the experiments.

Determination of furfural content and adsorption-desorption experiments
A colorimetric method was used to analyze the furfural concentration of the samples. Furfural was measured at a wavelength of 277 nm using a double beam spectrophotometer (Model lambda 25-Perkin Elmer Company) [6].
Batch system was used to collect the required data and adsorption experiments were performed in 250 mL Erlenmeyer flasks. Determinate dose of NNZVI was added into the Erlenmeyer flask and was shaked immediately in regulated speed by shaker. After desired contact time, to separate adsorbents from aqueous solution, the samples were filtered through Whattman filter paper (0.2 µm) and then centrifuged (Eppendorf versatile 5810 series centrifuge) to simply calculate corresponding efficiency using Eq. (1) [7]: where C 0 and C t are respectively the initial and final concentrations of furfural.

Table 1
Parameters of the most common models applied to the adsorption kinetics of furfural onto synthesized NNZVI [1]. For kinetics studies, 0.5 g of adsorbents was contacted with 250 mL of furfural solutions in a beaker as carried out in previous step. In all kinetic experiments, the solution pH was kept at optimum value of E 2, which was adjusted using 0.1 N HCl or NaOH solutions and measured using a pH meter (Sense Ion 378, Hack). The furfural adsorption capacities at equilibrium, q e (mg furfural/g adsorbents), was determined using Eq. (2): where C 0 and C t are initial and final concentrations of furfural (mg/L), V is the volume of solution (L), and m is the nanoparticles mass (g) as dry.