Objetivou-se neste trabalho avaliar a influência do tempo de detenção hidráulica (TDH) na remoção do surfactante aniônico, alquilbenzeno linear sulfonado (LAS), de água residuária de lavanderia, em dois reatores de leito fluidificado (RLF) operados em TDH de 8 horas (RLF1) e 12 horas (RLF2). Os reatores foram inoculados com biomassa de lodos ativados e foi investigado a influência da adição de nitrato e etanol na degradação do LAS e seus impactos na comunidade microbiana. Para tal fim, o trabalho foi desenvolvido nas fases que se seguem: caracterização da água residuária de lavanderia comercial, ensaio de degradação desnitrificante de LAS, operação dos reatores de leito fluidificado, planejamento experimental de condições ótimas de degradação de surfactante em reatores em batelada e caracterização microbiana do consórcio microbiano do RLF1 e RLF2 por meio do Illumina MiSeq. Verificou-se considerável remoção de LAS (77%) no ensaio de degradação sob condição desnitrificante nos reatores em batelada com 21 mgLAS/L e adição de 100 mgNO3-/L. Ao longo de 436 dias de operação, verificou-se elevada remoção de LAS em RLF1 e RLF2, todavia, observou-se diferença significativa; ou seja, maior remoção global de LAS (99±3%) para 22,5±5,9 mg /L afluente em RLF2. A adição de etanol influenciou, notadamente, a remoção de LAS em RLF1, por outro lado a adição de nitrato exerceu influência na remoção de LAS em ambos os reatores. Na realização do planejamento experimental, em reatores em batelada, pode-se obter condições ótimas de degradação de LAS, verificando-se os valores críticos para etanol de 97,5 mg /L, e de 87,5 mg /L para nitrato. Para as seis etapas de operação foram identificados gêneros relacionados à desnitrificação e a degradação de LAS. Para Etapa I, foram identificadas bactérias relacionadas com a redução de nitrato, dentre eles Flavobacterium, Sphingobium e Xanthobacter. Para as etapas com adição de surfactante (II, III, IV, V e VI) identificou-se Dechloromonas, Zoogloea, Novosphingobium, Pseudomonas, Acinetobacter e Desulfobulbus, provavelmente relacionadas à degradação de LAS. / The aim of this study was to evaluate the influence of hydraulic retention time (HRT ) on anionic surfactant; linear alkyl benzene sulphonate (LAS) from laundry wastewater in two fluidized bed reactors (FBR) operated in HRT of 8 hours (FBR1) and 12 hours (FBR2). The reactors were inoculated with activated sludge and the influence of nitrate and ethanol addition on LAS removal was studied with subsequent impact on microbial diversity. The study was conducted in following phases; laundry wastewater characterization, denitrifying degradation potential of LAS, fluidized bed reactor operation under specified conditions, central composite design, and determination of microbial shift between biofilm of FBR1 and FBR2 through Mi-Seq Illumima®. Higher LAS removal (77%) was verified in denitrifying potential degrading of LAS using batch reactors feed with 21 mg LAS /L and 150mg NO3-/L. Great LAS removal efficiency was observed for 436 days, however significant notice was observed for global LAS removal between FBR1 and FBR2, i.e. greater LAS removal in FBR2 (99±3% for 22,5 ±5,9 mg LAS/L) than FBR1 (93 ±12% for 20,6 ±4,4 mg LAS /L). The ethanol addition significantly influenced FBR1 efficiency while nitrate addition improves LAS removal in both reactors. Central composite design resulted into optimal values for LAS removal (94%) in addition to 97,5 mg/L ethanol and 87,5 mg/L nitrate. Microbial shift showed genus abundance related to denitrification and LAS degradation. In Step I denitrifying bacteria Flavobacterium, Shingobium and Xanthobacter were identified. For Steps with laundry wastewater addition, Dechloromonas, Zoogloea, Novosphingobium, Pseudomonas, Acinetobacter and Desulfobulbus, were identified, probably, related to LAS degradation.

Objetivou-se neste trabalho avaliar a influência do tempo de detenção hidráulica (TDH) na remoção do surfactante aniônico, alquilbenzeno linear sulfonado (LAS), de água residuária de lavanderia, em dois reatores de leito fluidificado (RLF) operados em TDH de 8 horas (RLF1) e 12 horas (RLF2). Os reatores foram inoculados com biomassa de lodos ativados e foi investigado a influência da adição de nitrato e etanol na degradação do LAS e seus impactos na comunidade microbiana. Para tal fim, o trabalho foi desenvolvido nas fases que se seguem: caracterização da água residuária de lavanderia comercial, ensaio de degradação desnitrificante de LAS, operação dos reatores de leito fluidificado, planejamento experimental de condições ótimas de degradação de surfactante em reatores em batelada e caracterização microbiana do consórcio microbiano do RLF1 e RLF2 por meio do Illumina MiSeq. Verificou-se considerável remoção de LAS (77%) no ensaio de degradação sob condição desnitrificante nos reatores em batelada com 21 mgLAS/L e adição de 100 mgNO3-/L. Ao longo de 436 dias de operação, verificou-se elevada remoção de LAS em RLF1 e RLF2, todavia, observou-se diferença significativa; ou seja, maior remoção global de LAS (99±3%) para 22,5±5,9 mg /L afluente em RLF2. A adição de etanol influenciou, notadamente, a remoção de LAS em RLF1, por outro lado a adição de nitrato exerceu influência na remoção de LAS em ambos os reatores. Na realização do planejamento experimental, em reatores em batelada, pode-se obter condições ótimas de degradação de LAS, verificando-se os valores críticos para etanol de 97,5 mg /L, e de 87,5 mg /L para nitrato. Para as seis etapas de operação foram identificados gêneros relacionados à desnitrificação e a degradação de LAS. Para Etapa I, foram identificadas bactérias relacionadas com a redução de nitrato, dentre eles Flavobacterium, Sphingobium e Xanthobacter. Para as etapas com adição de surfactante (II, III, IV, V e VI) identificou-se Dechloromonas, Zoogloea, Novosphingobium, Pseudomonas, Acinetobacter e Desulfobulbus, provavelmente relacionadas à degradação de LAS. / The aim of this study was to evaluate the influence of hydraulic retention time (HRT ) on anionic surfactant; linear alkyl benzene sulphonate (LAS) from laundry wastewater in two fluidized bed reactors (FBR) operated in HRT of 8 hours (FBR1) and 12 hours (FBR2). The reactors were inoculated with activated sludge and the influence of nitrate and ethanol addition on LAS removal was studied with subsequent impact on microbial diversity. The study was conducted in following phases; laundry wastewater characterization, denitrifying degradation potential of LAS, fluidized bed reactor operation under specified conditions, central composite design, and determination of microbial shift between biofilm of FBR1 and FBR2 through Mi-Seq Illumima®. Higher LAS removal (77%) was verified in denitrifying potential degrading of LAS using batch reactors feed with 21 mg LAS /L and 150mg NO3-/L. Great LAS removal efficiency was observed for 436 days, however significant notice was observed for global LAS removal between FBR1 and FBR2, i.e. greater LAS removal in FBR2 (99±3% for 22,5 ±5,9 mg LAS/L) than FBR1 (93 ±12% for 20,6 ±4,4 mg LAS /L). The ethanol addition significantly influenced FBR1 efficiency while nitrate addition improves LAS removal in both reactors. Central composite design resulted into optimal values for LAS removal (94%) in addition to 97,5 mg/L ethanol and 87,5 mg/L nitrate. Microbial shift showed genus abundance related to denitrification and LAS degradation. In Step I denitrifying bacteria Flavobacterium, Shingobium and Xanthobacter were identified. For Steps with laundry wastewater addition, Dechloromonas, Zoogloea, Novosphingobium, Pseudomonas, Acinetobacter and Desulfobulbus, were identified, probably, related to LAS degradation.

Microfibers, textile fibres shorter than 5 mm, and are shed from fabrics during wear and released into the laundry effluent during washing. When passed through the wastewater treatment plant (WWTP), they adsorb toxins, heavy metals and pathogens before being released into the environment. Synthetic microfibers persist for long periods of time in aquatic environments and very little is known about the degradation of processed natural fibres. Hydrocyclonic separation was studied as a way to separate the microfibers from the effluent before being they get additionally contaminated at the WWTP. A hydrocyclone has no moving parts and functions by utilizing centrifugal force and the difference in specific gravity between the fluid and the particles that are to be separated. The separation efficiency is dependent on its dimensional and operation parameters. No previous studies on hydrocyclonic separation of microfibres were found. Polyester fleece blankets were washed. The effluent was filtered, and the filters weighed to determine the mass of the separated fibres. Sampling of the inhomogeneous effluent presented a challenge and larger sample volumes would be needed to adequately represent the population. Using a Büchner funnel, filter fouling led to filtration times of up to 6 h for 1 l of effluent. Dividing the 1 l samples into two 0.5 l samples, filtering separately and adding the weight reduced filtration time to 2 h and the results were not significantly different from filtering the whole 1 l sample with one filter. The hydrocyclones tested separated around 11% of the total weight of microfibers in the effluent, too low to be deemed viable. As only a few dimensional variables were tested, it could possible that a higher fraction could be separated with this method. Given that the commercially available filtration systems separate 30-80%, refining existing methods may yield better results.