RESUMO
Organic micropollutants are often found in domestic and industrial effluents. Thus, it is important to learn their fate, the metabolites generated and their sorption during biological treatment processes. This work investigated the biodegradation of 14C-dicofol organochloride during wastewater aerobic treatment and sludge anaerobic biodigestion. The performance of these processes was evaluated by physical-chemical parameters. Radioactivity levels were monitored in both treatments, and residues of dicofol (DCF) and dichlorobenzophenone (DBP) were quantified by HPLC/UV. The efficiency of the aerobic and anaerobic processes was slightly reduced in the presence of DCF and DBP. After aerobic treatment, only 0.1% of DCF was mineralized, and 57% of radioactivity remained sorbed on biological sludge as DBP. After 18 days of anaerobiosis, only 3% of DCF and 5% of DBP were detected in the sludge. However, 70% of radioactivity remained in the sludge, probably as other metabolites. Dicofol was biodegraded in the investigated process, but not mineralized.
Assuntos
Bactérias Aeróbias/metabolismo , Bactérias Anaeróbias/metabolismo , Dicofol/metabolismo , Herbicidas/metabolismo , Resíduos Industriais/prevenção & controle , Esgotos/microbiologia , Purificação da Água/métodos , Biodegradação Ambiental , Radioisótopos de Carbono/isolamento & purificação , Radioisótopos de Carbono/metabolismo , Dicofol/isolamento & purificação , Herbicidas/isolamento & purificação , Marcação por Isótopo , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/metabolismoRESUMO
The fate of organochlorine 14C-dicofol in activated sludge process was investigated. Results showed that the major part of radioactivity remained adsorbed on biological sludge. Consequently, its final disposal deserves special attention. The small amounts of dicofol, biotransformed or not, which remained in the treated effluent could contaminate receiving bodies.
A dinâmica do organoclorado 14C-dicofol no processo de lodos ativados foi investigada. Os resultados mostraram que a maior parte da radioatividade ficou adsorvida no lodo biológico. Consequentemente, o seu descarte final merece atenção especial. Pequenas quantidades de dicofol, biotransformadas ou não, permanecem no efluente tratado podendo contaminar os corpos receptores.