Adsorption of Chromium (VI) from Aqueous Solution Using Palm Leaf-Derived Biochar: Kinetic and Isothermal Studies

In this study, biochar produced by low-temperature pyrolysis from palm leaves was treated with phosphoric acid in order to increase the sorption efficiency of Cr (VI) from aqueous solutions. Numerous characterization experiments using BET surface area, FE-SEM and FT-IR showed that the phosphoric acid-treated biochar (TBC-P) was covered with P particles. In comparison to the palm leaves and biochar, the TBC-P also had more surface oxygenated functional groups, surface area, pore size and internal structure. FTIR analysis showed that the functional groups of pretreated biochar were similar to those of biochar. Batch adsorption experiments showed that the TBC-P had a strong sorption ability to Cr (VI), with the highest removal efficiency of 99% at a low pH value of 2.0, which was significantly higher than that of the untreated biochar. The kinetic study has shown that the mechanism of the reaction was well represented by the second-order model, while isotherm data were well presented by the Langmuir model. The TBC-P was successfully regenerated using a 0.1 M HCl solution

REMOVAL OF PHENOL FROM WASTEWATER USING LOWCOST ADSORBENTS DEVELOPED FROM RICE HUSK

Organic contaminants from industrial waste streams have been recognised as an issue of growing concern as they severely affect human health and the environment. In this research, the development of twenty six (26) low-cost adsorbent materials from abundant waste rice husk was achieved via chemical treatment, thermal treatment and activated rice husk (activated carbon). The physiochemical properties of the developed adsorbent were evaluated. Their adsorption behaviours in batch system were evaluated for the removal of phenol from aqueous solutions by varying the initial concentration, pH, required dose, contact time and temperature. Subsequently, the adsorption behaviour of the best adsorbent in fixed bed column was further evaluated for phenol, binary system of phenol with benzene and toluene as well as ternary system of phenol, benzene and toluene. Analysis showed that the developed adsorbents possessed different physiochemical properties due to the methods of treatment. It was found that, the surface morphology of rice husk was progressively changed after treatment. It was also found that, the activated carbons have the highest surface areas ranged from (117.78 to 586.6 m2 g-1 ) followed by thermally (24.04 to 201.4 m2 g' 1 ) and chemically (2.78 to 50.17 m2.g-1 ) treated samples, respectively. Experimental results in batch system show that adsorption capacity was found to increase with increase in initial concentration, adsorbent dose and agitation time. The maximum uptake of phenol was found at pH 4. Due to high surface areas and porosity, at 100 mg.L-1 of synthetic wastewater containing phenol, the activated adsorbents had shown the highest removal efficiencies ranged from (86.7 to 98.5 %) followed by thermally (26.9 to 64.9 %) and chemically (22.5 to 48.6 %) treated adsorbents, respectively. Further evaluation of the best activated adsorbent, D6oo.u, in fixed bed column showed that the adsorption capacity increased with the increase in the initial concentration and the bed depth. However, it decreased with the increase in the feed flow rate

Biochar Derived from Palm Waste Supported Greenly Synthesized MnO₂ Nanoparticles as a Novel Adsorbent for Wastewater Treatment

Water pollution with dye effluents from different industries is a broadly established environmental and health problem that needs serious attention. In this study, making use of Acacia nilotica seed extract, greenly synthesized MnO2 nanoparticles were loaded on the surface of biochar derived from palm waste (MnO2/PF), with specific surface areas of 70.97 m2/g. Batch experiments were adopted, aiming to evaluate the performance of palm fronds, biochar, and the MnO2/PF adsorbents in methyl orange (MO) removal from an aqueous solution. The feedstock and synthesized biochars were comprehensively characterized using XRD, SEM-EDX, FTIR, and BET surface area techniques. Moreover, the influences of the modification of palm fronds, initial dye concentrations, pH, and adsorbent dosage on MO uptake were examined. The results demonstrated that MnO2/PF biochar nanocomposite led to an increase in the removal efficiency by 6 and 1.5 times more than those of palm fronds and biochar, respectively. In addition, it was found that the second-order kinetic model presented the kinetic adsorption very well. This paper demonstrates that the depositing of greenly synthesized MnO2 nanoparticles on the date palm waste biochar forms a novel adsorbent (MnO2/PF) for the removal of MO from aqueous solutions. Furthermore, this adsorbent was easy to synthesize under moderate conditions without the need for chemical capping agents, and would thus be cost-effective and eco-friendly

Preparation and characterization of rice husk adsorbents for phenol removal from aqueous systems.

Rice husk is a base adsorbent for pollutant removal. It is a cost-effective material and a renewable resource. This study provides the physicochemical characterization of chemically and thermally treated rice husk adsorbents for phenol removal from aqueous solutions. We revealed new functional groups on rice husk adsorbents by Fourier transform infrared spectroscopy, and observed major changes in the pore structure (from macro-mesopores to micro-mesopores) of the developed rice husk adsorbents using scanning electron microscopy. Additionally, we studied their surface area and pore size distribution, and found a greater enhancement of the morphological structure of the thermally treated rice husk compared with that chemically treated. Thermally treated adsorbents presented a higher surface area (24-201 m2.g-1) than those chemically treated (3.2 m2.g-1). The thermal and chemical modifications of rice husk resulted in phenol removal efficiencies of 36%-64% and 28%, respectively. Thus, we recommend using thermally treated rice husk as a promising adsorbent for phenol removal from aqueous solutions

Analyzing the Spatial Correspondence between Different Date Fruit Cultivars and Farms’ Cultivated Areas, Case Study: Al-Ahsa Oasis, Kingdom of Saudi Arabia

Diversity in date palm (DP) cultivars plays a crucial role in the agroecosystems of several countries, such as the Kingdom of Saudi Arabia (KSA). This study aims to map and analyze the spatial distribution of the most grown DP cultivars (Khlas, Ruziz, and Shishi) in the Al-Ahsa oasis in the KSA and to highlight their spatial correlation with the corresponding cultivated patches within farms. Descriptive and spatial data on 288 farms were analyzed using GIS, data curation, cross-TAB statistics, clustering maps, and spatial autocorrelation techniques. The obtained results revealed that most of the oasis’s DP farms are within a cultivated area of <500 m2. The larger cultivated areas are mostly in the oasis’s northern and central subregions, agreeing with the spatial distribution of trees. In total, 56.9% of the studied farms grew the cultivars together within the least rank (<500 m2) of cultivated area, having the greatest tendency for DP cultivation. Khlas was the most dominant cultivar being the least absent from cultivation with 3.1% compared to Ruziz (31.9%) and Shishi (37.8%). The spatial distribution of DP plantations in the oasis was also consistent with the spatial variation in soils and irrigation water salinity, necessitating the need for special agricultural extension programs. In conclusion, these outcomes indicate that this study is essential for DP sustainability, growers, authorities, and policy makers

Analyzing the Spatial Correspondence between Different Date Fruit Cultivars and Farms’ Cultivated Areas, Case Study: Al-Ahsa Oasis, Kingdom of Saudi Arabia

Diversity in date palm (DP) cultivars plays a crucial role in the agroecosystems of several countries, such as the Kingdom of Saudi Arabia (KSA). This study aims to map and analyze the spatial distribution of the most grown DP cultivars (Khlas, Ruziz, and Shishi) in the Al-Ahsa oasis in the KSA and to highlight their spatial correlation with the corresponding cultivated patches within farms. Descriptive and spatial data on 288 farms were analyzed using GIS, data curation, cross-TAB statistics, clustering maps, and spatial autocorrelation techniques. The obtained results revealed that most of the oasis’s DP farms are within a cultivated area of 2. The larger cultivated areas are mostly in the oasis’s northern and central subregions, agreeing with the spatial distribution of trees. In total, 56.9% of the studied farms grew the cultivars together within the least rank (2) of cultivated area, having the greatest tendency for DP cultivation. Khlas was the most dominant cultivar being the least absent from cultivation with 3.1% compared to Ruziz (31.9%) and Shishi (37.8%). The spatial distribution of DP plantations in the oasis was also consistent with the spatial variation in soils and irrigation water salinity, necessitating the need for special agricultural extension programs. In conclusion, these outcomes indicate that this study is essential for DP sustainability, growers, authorities, and policy makers

Fixed-Bed Adsorption of Phenol onto Microporous Activated Carbon Set from Rice Husk Using Chemical Activation

In the course of this research, the potential of activated carbon from rice husk was examined as being a phenol removal medium from an aqueous solution in a fixed-bed adsorption column. The activated carbon was characterized through FESEM (Field-Emission Scanning Electron Microscopy) and BET (Brunauer–Emmett–Teller) surface area. According to the FESEM micrograph and BET surface area, RHAC (rice husk activated carbon) had a porous structure with a large surface area of 587 m2·g−1 and mean diameter of pores of 2.06 nm. The concentration effects on the influent phenol (100–2000 mg·L−1), rate of flow (5–10 mL·min−1), and bed depth (8.5–15.3 cm) were examined. It was found that the capacity of bed adsorption increased according to the increase in the influent concentration and bed depth. However, the capacity of bed adsorption decreased according to the increase in the feed flow rate. The regeneration of activated carbon column using 0.1 M sodium hydroxide was found to be effective with a 75% regeneration efficiency after three regeneration cycles. Data on adsorption were observed to be in line with many well-established models (i.e., Yoon–Nelson and Adams–Bohart, as well as bed depth service time models)

Fixed-Bed Adsorption of Phenol onto Microporous Activated Carbon Set from Rice Husk Using Chemical Activation

In the course of this research, the potential of activated carbon from rice husk was examined as being a phenol removal medium from an aqueous solution in a fixed-bed adsorption column. The activated carbon was characterized through FESEM (Field-Emission Scanning Electron Microscopy) and BET (Brunauer–Emmett–Teller) surface area. According to the FESEM micrograph and BET surface area, RHAC (rice husk activated carbon) had a porous structure with a large surface area of 587 m2·g−1 and mean diameter of pores of 2.06 nm. The concentration effects on the influent phenol (100–2000 mg·L−1), rate of flow (5–10 mL·min−1), and bed depth (8.5–15.3 cm) were examined. It was found that the capacity of bed adsorption increased according to the increase in the influent concentration and bed depth. However, the capacity of bed adsorption decreased according to the increase in the feed flow rate. The regeneration of activated carbon column using 0.1 M sodium hydroxide was found to be effective with a 75% regeneration efficiency after three regeneration cycles. Data on adsorption were observed to be in line with many well-established models (i.e., Yoon–Nelson and Adams–Bohart, as well as bed depth service time models)