Column efficiency of fluoride removal using Quaternized Palm Kernel Shell (QPKS)

In this research, the adsorption potential of quaternized palm kernel shell (QPKS) to remove F− from aqueous solution was investigated using fixed-bed adsorption column. Raw palm kernel shell waste was reacted with 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHMAC) in order to modify the surface charge. The effects of inlet F− concentrations (2–12 mg/l) and QPKS bed height (2–10 cm) with optimum pH (pH = 3) on the breakthrough characteristics of the adsorption system were determined. In the fixed-bed column, breakthrough time increases with increasing bed height due to increasing amount of active site on adsorbents to adsorb the fluoride ion. Decreasing trend of breakthrough values was obtained with increasing initial fluoride concentration due to greater driving force for the transfer process to overcome the mass transfer resistance in the column. The adsorptions were fitted to three well-established fixed-bed adsorption models, namely, Thomas, Yoon–Nelson, and Adams–Bohart models. The results fitted well to the Thomas and Yoon–Nelson models with correlation coefficient, R2 ≥ 0.96

Removal of fluoride using quaternized palm kernel shell as adsorbents: equilibrium isotherms and kinetics studies

Palm kernel shell (PKS) core fibers, an agricultural waste, were chemically modified using N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHMAC) as a quaternizing agent. The potential of quaternized palm kernel shell (QPKS) as an adsorbent for fluoride in an aqueous solution was then studied. The quaternized palm kernel shell (QPKS) core fibers were characterized using Fourier transform infrared spectroscopy (FTIR) and a scanning electron microscope (SEM). The effect of various factors on the fluoride sequestration was also investigated. The results showed that with an increase in the adsorbent amount and contact time, the efficiency of fluoride removal was improved. The maximum fluoride uptake was obtained at pH 3 and a contact time of 4 h. The adsorption behavior was further investigated using equilibrium isotherms and kinetics studies. The results from these studies fit well into Freundlich, Redlich-Peterson, and Sips isotherm’s with a coefficient of determination (R2) of 0.9716. The maximum fluoride removal was 63%. For kinetics studies, the pseudo-second order was the best fit for fluoride, with an R2 of 0.999. These results suggest that QPKS has the potential to serve as a low-cost adsorbent for fluoride removal from aqueous solutions

Removal of fluoride using quaternized palm kernel shell as adsorbents: Equilibrium isotherms and kinetics studies

Palm kernel shell (PKS) core fibers, an agricultural waste, were chemically modified using N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride (CHMAC) as a quaternizing agent. The potential of quaternized palm kernel shell (QPKS) as an adsorbent for fluoride in an aqueous solution was then studied. The quaternized palm kernel shell (QPKS) core fibers were characterized using Fourier transform infrared spectroscopy (FTIR) and a scanning electron microscope (SEM). The effect of various factors on the fluoride sequestration was also investigated. The results showed that with an increase in the adsorbent amount and contact time, the efficiency of fluoride removal was improved. The maximum fluoride uptake was obtained at pH 3 and a contact time of 4 h. The adsorption behavior was further investigated using equilibrium isotherms and kinetics studies. The results from these studies fit well into Freundlich, Redlich-Peterson, and Sips isotherm's with a coefficient of determination (R2) of 0.9716. The maximum fluoride removal was 63%. For kinetics studies, the pseudo-second order was the best fit for fluoride, with an R2 of 0.999. These results suggest that QPKS has the potential to serve as a low-cost adsorbent for fluoride removal from aqueous solutions

Adsorption of quarternized palm kernel shell for fluoride removal

The excess concentrations of fluoride in water for human consumption may cause severe health problems. Among several treatment technologies applied for fluoride removal, adsorption process has been explored widely and proven as an efficient method. An agricultural waste, palm kernel shell (PKS) was quartenized in order to improve the adsorption efficiency as an adsorbent for adsorbing fluoride from waste water by batch and fixed bed column process. Commercial palm kernel shell activated carbon (PKSAC) was used as a comparison to the quaternized palm kernel shell (QPKS). Effect of various factors on the fluoride removal was investigated, such as pH, initial concentration, adsorbent dosage and contact time. Adsorption capacity increased with the increased of adsorbent dosage and contact time. Optimum parameters which resulted in maximum adsorption capacity of 1.7 mg/g by QPKS and 1.3 mg/g by PKSAC was achieved at pH 3 with initial concentration of 20 mg/L, an adsorbent dosage of 8 g/L with contact time of 4 h. The adsorption behavior was further investigated using equilibrium isotherms. In batch process, isotherms such as Langmuir, Freundlich, Redlich-Peterson, and Sips were studied, in which Redlich-Peterson, Langmuir and Freundlich fit well with a coefficient correlation (R2), ranged from 0.95 to 0.99. Kinetic studies, such as pseudo first and second order, Boyd’s model, Elovich model, Double Exponential model and Intraparticle Diffusivities model, were investigated and showed parallel transports exist in the adsorption process and intraparticle diffusion is the rate limiting step for both adsorbents. In fixed bed column process, breakthrough time was affected by bed height and initial fluoride concentration and kinetics studies investigated were Adam-Bohart, Thomas and Yoon-Nelson Model. Regeneration study showed that QPKS performance decreased by 63% compared to PKSAC which decreased by 80% after four cycles of adsorption-desorption. These results suggest that quaterrnized palm kernel shell (QPKS) has the potential to serve as a low-cost adsorbent for fluoride removal from aqueous solutions

Immobilization of NanoFe3O4 onto Fabric Material through in situ Co-precipitation as a Flexible Catalyst for Humic Acid Degradation

Humic acid (HA) is a major component in dissolved natural organic matter (NOM) that is commonly found in natural water sources such as surface water and soil. Although HA is non-toxic, it is a precursor of carcinogenic and mutagenic disinfection by-products that will be generated when chlorine and chloramine are applied to disinfect water during the chlorination process. Hence, researchers have been investigating various strategies to remove HA from water sources and nanoparticles stood out as one of the preferred materials for the removal. However, owing to the tiny size of nanoparticles, the recycling, and removal of nanoparticles through sedimentation and centrifugation method is often time and energy-consuming. Therefore, this work set out to immobilize iron oxide nanoparticles (nanoFe3O4) onto fabric material to create a flexible catalyst that is feasible in degrading HA. The immobilization of nanoFe3O4 onto woven and non-woven fabrics was successfully done through in situ co-precipitation method. The flexible catalyst was found to be responsive to magnetic pull, which is one of the properties of nanoFe3O4 itself. On the other hand, scanning electron microscopy (SEM) images have verified the attachment of nanoFe3O4 was in an irregular pattern across the heterogeneous surface and it was grown on the fabric's filament instead of being trapped between the pores of the fabric. Subsequently, the as-made flexible catalysts were tested and found to be feasible as it can degrade HA completely in 24 to 36 h. More importantly, the flexible catalyst can be removed easily in an instant with a negligible detachment of nanoparticles from the fabric material. While this preliminary result is promising, it is suggested that further study should be carried out to optimize the efficiency of this novel flexible catalyst on the degradation of HA.Scopu

Fluoride removal by Palm Kernel Shell Activated Carbon (PKSAC): batch and isotherms approach

Fluoride, which is classified as one of the contaminant of water for human consumption by the World Health Organisation (WHO) has been recognised as one of the serious problem worldwide by contaminating the groundwater. According to WHO, the standard prescribed for fluo1ide ion concentration in drinking water is 1.0 mg/l. Higher concentration of fluoride causes dental fluorosis (1.5-2.0mg/l) and skeletal fluorosis (>3.0mg/l). In this study. adsorption was chosen as fluoride removal method. A good adsorption system required an efficient adsorbent at an optimum condition. An agricultural waste, palm kernel shell (PKS) which is locally available as abundant material. in the form of activated carbon was used as the adsorbent for adsorbing fluoride from waste water. Characteristic of PKSAC was analysed using BET and SEM analysis. BET results showed pore type of PKSAC which consist of mesopores and SEM analysis showed the image of the pores. Effect of various factors on the fluoride removal was investigated such as pH. initial concentration, adsorbent dosage and contact time. Adsorption capacity increased with the increased of adsorbent dosage and contact time probably clue to the increase in the mass transfer driving force, resulting in a higher loading capacity for PKSAC. as its active sit.es were occupied by a larger amount of fluoride ions. Optimum parameters which resulted in maximum adsorption capacity of l.3mg/ g and fluoride removal of 38% was achieved at pH 4 with initial concentration of 20 mg/L. an adsorbent dosage of 4 g/ L with contact time of 4 h. The adsorption behavior was further investigated using equilibrium isotherms. Isotherms such as Langmuir, Freundlich, Redlich-Peterson and Temkin were studied which shown Redlich-Peterson fit well with a coefficient correlation (R2) of 0.99. These results suggest that palm kernel shell activated carbon (PKSAC) has the potential to serve as a good adsorbent for fluoride removal from aqueous solutions