Agricultural solid waste for the removal of organics: adsorption of phenol from water and wastewater by palm seed coat activated carbon

Molva

International Journal of Mineral Processing

2006

A raw lignitic coal from Soma, Turkey was investigated to determine its potential as an adsorbent for phenol removal from wastewaters. Kinetic batch tests demonstrated that phenol could be completely removed from solution given sufficient solids loading and reaction time. The adsorption capacity of 10 mg/g obtained with the lignite is low compared to those achievable with activated carbons (around 300 mg/g). However, when normalized for the surface area, the adsorption capacity was much larger for the lignite (1.3 mg/m 2 ) than that generally observed with activated carbons (0.05-0.3 mg/m 2 ). Hydrogen-bonding of the phenolic -OH with the oxygen sites on the lignite surface is the most likely mechanism for adsorption. Though water molecules also have affinity for the same oxygen sites, lateral benzene ring interactions make phenol adsorption energetically more favorable. Since phenol molecules adsorbed in this fashion would project their benzene rings into solution, formation of a second layer through the action of the dispersive π-π interactions between the benzene rings is very likely. Residual water quality with respect to major elements and heavy metals was within acceptable limits defined by the ASTM standards. Dissolution of organic matter from the lignite was also observed to be negligible.

Section: Methodsmentioning

confidence: 99%

“…in appreciable quantities (Table 1) (Cermola et al, 2004;Kent, 1992;Rengaraj et al, 2002). Phenolic compounds have low allowable limits (0.5-1.0 mg/l) due to their toxicity to human and aquatic life and must be removed from wastewaters in environmentally acceptable ways.…”

Section: Introductionmentioning

confidence: 99%

Capacity and mechanism of phenol adsorption on lignite

Molva

International Journal of Mineral Processing

2006

“…It is attributed due to increase in adsorbent surface area and availability of more adsorption sites (Mehrizad et al 2009;Uddin et al 2007). The results also revealed that the adsorption efficiency increases with the increasing dose (Rengaraj et al 2002). The experimental output data are well-fitted with the ANN output data.…”

Section: Effect Of Adsorbent Dosagementioning

confidence: 55%

“…The WHO (2008) recommended threshold limit of phenol in potable water as 0.001 mg L -1 (Zeng et al 2009), while US Environmental Protection Agency (EPA) recommended the permissible limit of phenols in the wastewater\1 mg L -1 (Eahart et al 1977). Phenols can be removed from the aqueous solution through oxidation, precipitation, ion exchange, biodegradation, ultrasonic degradation, solvent extraction, ozonization and decomposition by fenton reagent (Aksu and Yener 2001;Rengaraj et al 2002). Adsorption is a well-established, low cost and powerful technique for treating domestic and industrial effluents.…”

Section: Introductionmentioning

confidence: 99%

“…Recent literature highlighted the extensive use of activated carbon in the field of wastewater treatment (Lotfy et al 2012;Olafadehan et al 2012). However, Many other adsorbents like bottom ash, brick-kilm ash, fly ash, peat, soil, rice husk, wood, saw dust, bagasse and carbonized bark are extensively used for removal of organic pollutants (Ademiluy et al 2009;Aksu and Yener 2001;Hamza et al 2012;Rengaraj et al 2002).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Neural network model and isotherm study for removal of phenol from aqueous solution by orange peel ash

et al. 2014

Artificial Neural Network model and isotherm study were done to predict the removal efficiency of phenol. An inexpensive adsorbent was developed from orange peel ash (OPA) for effective uptake of phenol from aqueous solution. The influence of different experimental parameters (initial concentration, pH, adsorbents dose, contact time, stirring rate and temperature) on phenol uptake efficiency was evaluated. Phenol was adsorbed by the OPA up to maximum of 97.34 %. Adsorption of phenol on OPA correlated well with the Langmuir isotherm model, implying monolayer coverage of phenol onto the surface of the adsorbent. The maximum adsorption capacity was found to be 3.55 mg g -1 at 303 K. Pseudo-second-order kinetic model provided a better correlation for the experimental data. Moreover, the activation energy of the adsorption process (E a ) was found to be -18.001 kJ mol -1 indicating physorption nature of phenol onto OPA. A negative enthalpy (DH°) value indicated that the adsorption process was exothermic. Again multi-layer Neural Network model was in very good agreement with the experimental results.

Asia-Pacific J Chem Eng

Assessment of the adsorption capacity of phenol on magnetic activated carbon

Júnior

Araújo

Simões

et al. 2021

In this work, an alternative utilization of agro-industrial waste coconut endocarp (Cocos nucifera L.) as raw material for the synthesis of magnetic adsorbent aiming the phenol removal is proposed. The synthetized adsorbent, denominated magnetic activated carbon (MAC), was prepared by coprecipitation of cobalt ferrite (CoFe 2 O 4 ) onto activated carbon surface obtained by carbonization of coconut endocarp. Characterization of MAC was carried out by point of zero charge (PZC), Brunauer, Emmett, and Teller (BET) surface area, scanning electron microscopy (SEM), x-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), x-ray diffractometry (XRD) analysis, and magnetization curves. Adsorption experiments were performed in batch system to evaluate kinetics and equilibrium of phenol adsorption. Adsorbent regeneration method was proposed to evaluate the reutilization of MAC in successive cycles of adsorption-desorption. Resultsshowed that obtained magnetic compounds present cubic phase structure covered in activated carbon surface. MAC has microporous structure with functional groups like carbonyl and hydroxyl that can behave as adsorption sites.Kinetic studies indicate that adsorption rate increased rapidly around the initial 60 min, reaching equilibrium at 240 min; following pseudo-first-order and pseudo-second-order kinetic models in characterization concentrations of 50 and 100 mg L À1 , only the second-order model fit the kinetic data at 150 mg L À1 , while both models were outside the chi-square interval at 200 and 230 mg L À1 . The adsorption equilibrium is represented by Langmuir isotherm with high adsorption capacity of 116.0 ± 3.61 mg g À1 . The desorption experiments revealed that adsorption capacities of MAC still viable after three adsorption-desorption cycles. It was observed that chemical affinity of small concentrations of methanol with phenol allowed to exert greater desorption capacity to other solvents with permanence of adsorbed phenol of 17.5 mg g À1 .