The use of argan nut shell as a precursor for producing activated carbon was investigated in this work. Two activated carbons AC-HP and AC-Na were prepared from argan nut shell by chemical activation method using phosphoric acid (HPO) and sodium hydroxide (NaOH), respectively. Textural, morphological, and surface chemistry characteristics were studied by nitrogen physisorption, TGA, SEM, TXRF, FTIR, XRD, and by determining the pH of the AC-HP. The adsorption experiments revealed that AC-HP was more efficient in adsorption of BPA due to high specific surface area (1372 m/g) compared to AC-Na (798 m/g). The obtained adsorption data of BPA on AC-HP correlated well with the pseudo-second-order model and the Langmuir isotherm (Qmax = 1250 mg/g at 293 K). The thermodynamic parameters (ΔG° < 0, ΔH° < 0, and ΔS° < 0) indicate that adsorption of BPA on AC-HP was spontaneous and exothermic in nature. The regeneration of AC-HP showed excellent results after 5 cycles (95-93%). This work does not only provide a potential way to use argan nut shell but also represents a sustainable approach to synthesize AC-HP, which might be an ideal material for various applications (energy storage, catalysis, and environmental remediation).

Highly microporous carbons were prepared from argan nut shell (ANS) using steam activation method. The carbons prepared (ANS@H2O-30, ANS@H2O-90, and ANS@H2O-120) were characterized using X-ray diffraction, scanning electron microscopy, Fourier-transform infrared, nitrogen adsorption, total X-ray fluorescence, and temperature-programmed desorption (TPD). The ANS@H2O-120 was found to have a high surface area of 2853 m2/g. The adsorption of bisphenol A and diuron on ANS@H2O-120 was investigated. The isotherm data were fitted using Langmuir and Freundlich models. Langmuir isotherm model presented the best fit to the experimental data suggesting micropore filling of ANS@H2O-120. The ANS@H2O-120 adsorbent demonstrated high monolayer adsorption capacity of 1408 and 1087 mg/g for bisphenol A and diuron, respectively. The efficiency of the adsorption was linked to the porous structure and to the availability of the surface adsorption sites on ANS@H2O-120. Response surface method was used to optimize the removal efficiency of bisphenol A and diuron on ANS@H2O-120 from aqueous solution. Graphical abstractᅟ Electronic supplementary materialThe online version of this article (10.1007/s11356-018-3455-3) contains supplementary material, which is available to authorized users.

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Hydrochar derived from Argan nut shell (ANS) was synthesized and applied to remove bisphenol A (BPA) and diuron. The results indicated that the hydrochar prepared at 200 °C (HTC@ANS-200) possessed a higher specific surface area (42 m 2 /g) than hydrochar (HTC@ANS-180) prepared at 180 °C (17 m 2 /g). The hydrochars exhibited spherical particles, which are rich in functional groups. The HTC@ANS-200 exhibited high adsorption efficiency, of about 92% of the BPA removal and 95% of diuron removal. The maximum Langmuir adsorption capacities of HTC@ANS-200 at room temperature were 1162.79 mg/for Bisphenol A and 833.33 mg/g for diuron (higher than most reported adsorbents). The adsorption process was spontaneous (− ΔG°) and exothermic (− ΔH°). Excellent reusability was reclaimed after five cycles, the removal efficiency showed a weak decrease of 4% for BPA and 1% for diuron. The analysis of Fourier transforms infrared spectrometry demonstrated that the aromatic C=C and OH played major roles in the adsorption mechanisms of BPA and diuron in this study. The high adsorption capacity was attributed to the beneficial porosity (The pore size of HTC@ANS-200 bigger than the size of BPA and diuron molecule) and surface functional groups. BPA and diuron adsorption occurred also via multiple adsorption mechanisms, including pore filling, π-π interactions, and hydrogen bonding interactions on HTC@ANS-200. Statement of NoveltyTo our knowledge, this is the first paper introduces a new technique to produce hydrochar from argan nut shell and its studies as an adsorbent for the removal of bisphenol A and diuron. This study does not only open up a novel way to recycle argan nut shell but also presents a beneficial approach to synthesize low-cost materials for wastewater treatment.

Abstract:The treatment of volatile organic compounds (VOC) emissions is a necessity of today. The catalytic treatment has already proven to be environmentally and economically sound technology for the total oxidation of the VOCs. However, in certain cases, it may also become economical to utilize these emissions in some profitable way. Currently, the most common way to utilize the VOC emissions is their use in energy production. However, interesting possibilities are arising from the usage of VOCs in hydrogen and syngas production. Production of chemicals from VOC emissions is still mainly at the research stage. However, few commercial examples exist. This review will summarize the commercially existing VOC utilization possibilities, present the utilization applications that are in the research stage and introduce some novel ideas related to the catalytic utilization possibilities of the VOC emissions. In general, there exist a vast number of possibilities for VOC OPEN ACCESSCatalysts 2015, 5 1093 utilization via different catalytic processes, which creates also a good research potential for the future.