Resumo Este trabalho teve como objetivo determinar duas drogas psicotrópicas mais dispensadas pelos Centros de Atenção Psicossocial (CAPS) nas águas de um rio urbano (sub-bacia do rio Belém, Curitiba - PR, Brasil). Foi desenvolvido e validado um método analítico SPE seguido de HPLC-DAD. Os cartuchos Strata-X® foram utilizados para extrair carbamezepina (CZ) e diazepam (DZ) das águas e as condições de SPE foram otimizadas por um planejamento fatorial 23. O método validado foi específico para compostos alvo. Os coeficientes de correlação foram superiores a 0,9998, a recuperação entre 85,8 e 98,4% e a precisão abaixo de 6,60% (RSD, n = 3). Este método foi aplicado com sucesso para analisar amostras de rios e pontos críticos de poluição foram reconhecidos. A CZ e DZ foram encontradas em concentrações variando de 0,670 a 0,856 μg L-1 e de LOQ a 0,763 μg L-1, respectivamente, confirmam que o consumo de drogas está diretamente relacionado à poluição do rio na região estudada.

Abstract This work sought to determine the two psychotropic drugs most commonly released by Psychosocial Care Centers (CAPS) into urban river waters (Belém sub-basin, Curitiba, PR, Brazil). A simple analytical method using SPE followed by a HPLC-DAD was developed and validated. Strata-X® cartridges were used to extract (carbamazepine) CZ and diazepam (DZ) from water and SPE conditions were optimized by 23 factorial design. The validated method was specific for target compounds; correlation coefficients were above 0.9998, recovery between 85.8 and 98.4% and precision below 6.60% (RSD, n=3). This method was successfully applied to analyze river samples and pollution hotspots were identified. The CZ and DZ concentrations found ranged from 0.670 to 0.856 µg L-1 and from LOQ to 0.763 µg L-1, respectively, and confirmed that drug consumption is directly related to river pollution in the studied region.

The effect of moisture content in the steam treatment and enzymatic hydrolysis of sugarcane bagasse was evaluated. Steam treatment was perfomed at 195-210 ºC for 4-8 min using cane bagasse with moisture contents in the range 16-100 wt% (dry basis). Increased moisture contents not only had a positive influence in recovery of main cane biomass components but also resulted in better substrates for enzymatic hydrolysis. As a result, drying is not required for optimal pretreatment and enzymatic hydrolysis of sugarcane bagasse, which can be processed into second generation ethanol immediately after crushing and hot water washing.

The clay minerals montmorillonite (MT) and vermiculite (VT), previously treated with Ca2+, K+ and Na+, were employed in a sorption study with herbicides. The herbicides 2,4-D, diuron, alachlor and metolachlor showed no interaction with MT and VT. On the other hand, the triazines presented a good sorption process, close to 100% for ametrine removal and near to 56 and 69% for atrazine and simazine, respectively, by MT. These results suggest that the MT specie may be a good material for triazines removal from aqueous medium and an alternative phase to preconcentration process, besides to exhibit a good selectivity.

The aim of this paper was to evaluate alterations in the quality of the water of the Tibagi River caused by the urban and industrial activities in the region of Ponta Grossa. The study involved the monitoring of physico-chemical and microbiological parameters of the water body, which were evaluated by a principal components analysis routine. Sample collections were carried out monthly during one year (October of 2005 to September of 2006), at 3 sampling points: upstream and downstream of the industrial district and downstream from the city of Ponta Grossa. The principal components analysis showed the effect of point sources associated with industrial activity, which contribute to the rise of total concentration of amoniacal nitrogen and the reduction of dissolved oxygen in the studied region.