Production of activated carbon from petroleum cake and its application in water treatment for the removal of metals and phenol ~ ~ cn () (D" :J g O> :J a. -i ~ :J" :J o o- co '< < 2- ~ '" z o 1/1 I "C "C -4 -4 CD .!. '" m @ ~ » "U c Q: 0;" :J" 3" co '" o o o R.M. Ramírez Zamora*, R. Schouwenaars**, A. Durán Moreno *** and G. Buitrón * *Instituto de Ingeniería, UNAM. Apdo. Postal 70-472, Coyoacán 04510, México (E-mail: rmrz@pumas.iingen.unam.mx) **Departamento de Ingeniería Mecánica, Facultad de Ingeniería, UNAM, Anexo de Ingeniería, Circuito exterior sIn, Coyoacán, 04510 México ***Fac. de Química, UNAM, Edif. E planta baja, Paseo de la Investigación Científica, Coyoacán 04510, México Abstract The feasibility of the reuse of petroleum cake, withof high sulphur content, produced as waste in a Mexican petroleum refinery, its properties for use in water treatment was were assessed. Several classical activation methods were used and the physicochemical characteristics of the treated material were measured using normal ASTM standards. Use of scanning electron microscopy and microprobe analysis permilted most of the effects of the activation processes on the structure and properties of the cake. Adsorption capacities of mercury and silver and physicochemical characteristics determined for these activated carbons as well as scanning electron microscopy show that the HaPO 4 is the best activating agent. It is shown that the process is highly promising for the production of an activated carbon aimed at the removal of heavy metals from wastewater. Keywords Activated carbon; metal removal; petroleum cake; SEM; wastewatertreatment I ntrod uction In 2000, fue largest petroleum refinery in Mexico goes into operation at Cadereyta, Nuevo León. The most important salid waste product expectedto originate from this plant will be petroleum cake (3,000 tonnes/day). Taking into account the high productionrates of this residual it is interesting to promote research to find altemative applications for this producto Processes that can be considered for fue reuse of petroleum cake are gasification, energy production by combustion and fue recuperation of metals from contaminated waters (Di Panfilo and Egiebor, 1995). Nevertheless, fue first two options confront severe technologi- callimitations due to fue high sulphur contents (6 wt. % ) of fue cake underconsideration. In this context, fue production of activated carbon for wastewater treatrnent remains as an interesting option. The adsorption capacity of activated carbons and its applications depend on fue base material involved and fue processingparameters.By fine-tuned physicochemical process- es it is possible to influence fue its pare structure, surface afea, density and surface chem- istry. Factors to be considered are fue temperatures of fue process,time at temperature, activating agent and oxidant flow rateo Activated carbon can be produced from materials consisting mainly of carbon by applying physical or chemical methods, which have as an objective fue generationof a high specific afea due to a strongly developedmicroporosity. This goal is reachedby removing or modifying aromatic and non-aromatic chainmolecules from fue carbon in favour of fue aromatic sheets, which are presentin carburized materials. The resulting loss of material (usually between 20 and 50%) provokes fue formation of a microporosity between fue original aromatic sheets, which is responsible for fue high 119