• Applied Chemistry for Engineering
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• v.29 no.4
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• pp.388-394
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• 2018

The removal of 2,4-dichlorophenol (2,4-dichlorophenol, 2,4-DCP) in aqueous solution was studied using the magnetic activated carbon (MAC) prepared from waste citrus peel. The adsorption characteristics of 2,4-DCP by MAC were investigated by varying the contact time, MAC dose, solution temperature, pH and 2,4-DCP concentration. The isothermal adsorption data were well explained by the Langmuir isotherm model equation and the maximum adsorption capacity calculated from the Langmuir isotherm equation was 312.5 mg/g. The adsorption kinetic data were well described by the pseudo-second-order reaction equation. The intraparticle diffusion model data indicated that both the film and intraparticle diffusion occur simultaneously during the adsorption process. The thermodynamic parameters of ${\Delta}H^o$ and ${\Delta}G^o$ have positive and negative values, respectively, indicating that the adsorption of 2,4-DCP by MAC is a spontaneous endothermic reaction. After the adsorption experiment was completed, the used MAC could be easily separated by an external magnet.

• Applied Chemistry for Engineering
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• v.10 no.3
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• pp.349-353
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• 1999

A study was carried out to see the effects of phenol on the biological degradation of a wastewater containing 2,4-dichlorophenol and 2,4-dinitrophenol and the biodegradation kinetic coefficients of Eckenfelder's modified model for the activated sludge process. The system containing base mix (BM) which was formulated with essential energy sources and nutrients was run down and washed out when 2,4-dichlorophenol and 2,4-dinitrophenol was introduced into the base mix unit without acclimation to phenol. Whereas for the system acclimated to phenol, the treatment efficiency was 91.9% in terms of $BOD_5$ and treatability for each chemical of phenol, 2,4-dichlorophenol, and 2,4-dinitrophenol was 99.8%, 43.3% and 62.5% based on concentration, respectively. Additional BM was added into the combined unit containing phenol, 2,4-dichlorophenol, 2,4-dinitrophenol so that the better treatment efficiency was achieved for each compound. The biokinetic coefficient of Eckenfelder's modified model without phenol acclimation was not estimated because the system did not reach the steady state. Thc coefficient for the phenol acclimation was 12.44 /day, however it was changed as 46.91 /day in addition of both of phenol acclimation and 47 mg/l of BM. The results presented above could be useful for the process design and further study in the field of biodegradation of benzene derivatives.