Physicochemical, microbiological and parasitological characterization of the filter backwash water from a water treatment plant of Blumenau - SC and alternatives for treatment and reuse

Caracterização físico-química, microbiológica e parasitológica da água de retrolavagem dos filtros de uma estação de tratamento de água de Blumenau - SC e alternativas para tratamento e reuso

Abstract

Filter Backwash Water (FBW) from water treatment plants (WTP) is composed of raw water waste, chemicals and microorganisms. Inappropriate disposal of this residue impacts negatively in the environment and in the health of human populations. Aiming to characterize the FBW from one WTP of Blumenau-SC, physiochemical, microbiological and parasitological assessments and tests with different flocculants polymers were performed in order to propose strategies for treatment and reuse of this residue. Subsequently treated liquid is discharged into the Itajaí-Açu River (Class 2). Physicochemical and microbiological analyses showed results higher than those permitted by CONAMA Resolution n° 430/2011 and Giardia duodenalis (Assembly B) cysts and Cryptosporidium spp. oocyst positivity was observed, characterizing as polluted and contaminated residue that shouldn't be released in the hydric body. The anionic flocculant polymer showed satisfactory results in the turbidity sample reduction (99.49%), which may be a promising alternative in the treatment of this residue.

Keywords:
Cryptosporidium spp.; Giardia spp.; wastes from WTP.