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

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.

Recirculation of Backwash Water in the Water Treatment Plant for the Needs of the Combined Heat and Power Plant

“…The composition of the backwashings produced at the surface water treatment plants is strongly correlated with the quality of the abstracted water, which changes throughout the year. These backwashings contain large amounts of post-coagulation suspension, as well as organic and mineral compounds, microorganisms, protozoa and heavy metals [Petris et al 2019, Mahdavi et al 2018, Leszczyńska and Sozański 2009. The backwashings quality is also influenced by the degree of their dilution related to the filter backwashing frequency and parameters [Komorowska-Kaufman and Lasocka-Gomuła 2018].…”

“…In order to be able to return the backwashings to the water treatment line, it is often necessary to prepare them in advance. It usually involves the removal of contaminants by sedimentation [Kučera and Hanušová, 2018], which can be accelerated by dosing lime and polyelectrolytes [Petris et al 2019, Arendze and Sibiya 2014, Kuś and Koźmiński 1993]. Increasingly, ultra and microfiltration is also used to purify the recycled filter backwashings, it is an expensive solution, so it is recommended to use other equally effective but low-cost alternatives [Shafiquzzaman et al 2021].…”

Effect of different filters on the extraction of norbixin from Bixa orellana for synthetic fiber dyeing and development of a post-dyeing process for removal of the unfixed dye

“…The textile industry has a high economic and social importance and a great diversity of processes are used to manufacture colored fabrics, ensuring income to millions of people (Criado et al, 2020). However, they are associated with a high consumption of water and consequently generate large amounts of effluent (Chicatto et al, 2018a;Petris et al, 2019;Rainert et al, 2017). In some stages of the textile industry processes, notably dyeing, aggressive chemicals, such as synthetic dyes, are used, which generate colored and potentially toxic effluents resulting in adverse effects on the environment if not properly treated (Rainert et al, 2021).…”