Removal efficiency of dissolved organic matter from secondary effluent by coagulation-flocculation processes

Guimarães, Natália Rodrigues; Dörr, Fabiane; Marques, Rodrigo de Oliveira; Pinto, Ernani; Filho, Sidney Seckler Ferreira

doi:10.1080/10934529.2020.1856580

Cited by 2 publications

(2 citation statements)

References 34 publications

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“…The removal values showed an improvement compared with the previous test (58.1 ± 0.3 COD, 94.9 ± 0.2 TSS and 89.8 ± 0.8 turbidity), although the values predicted by the design software were not achieved. Guimarães et al [46] tested several coagulants (including aluminium sulphate at 40 mg/L Al) and reached COD removal efficiencies (38%) below those achieved in this study (58%). On the other hand, Salem et al [47] reported Subsequently, coagulation tests were carried out with the optimum conditions obtained from the software.…”

Section: Optimization Of the Operating Conditions For The C/f Processcontrasting

confidence: 51%

Impact of Sidestream Pre-Treatment on Ammonia Recovery by Membrane Contactors: Experimental and Economic Evaluation

et al. 2022

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Membrane contactor is a promising technology for ammonia recovery from the anaerobic digestion centrate. However, high suspended solids and dissolved organic matter concentrations can reduce the effectiveness of the technology. In this study, coagulation–flocculation (C/F) and aeration pre-treatments were evaluated to reduce chemical oxygen demand (COD), turbidity, suspended solids and alkalinity before the ammonia recovery stage using a membrane contactor. The mass transfer coefficient (Km) and total ammonia (TAN) recovery efficiency of the membrane contactor increased from 7.80 × 10−7 to 1.04 × 10−5 m/s and from 8 to 67%, respectively, after pre-treating the real sidestream centrate. The pre-treatment results showed that dosing aluminium sulphate (Al2(SO4)3) at 30 mg Al/L was the best strategy for the C/F process, providing COD, turbidity and TSS removal efficiencies of 50 ± 5, 95 ± 3 and 90 ± 4%, respectively. The aeration step reduced 51 ± 6% the HCO3− content and allowed reducing alkaline consumption by increasing the pH before the membrane contactor. The techno-economic evaluation showed that the combination of C/F, aeration and membrane contactor can be economically feasible for ammonia recovery. Overall, the results of this study demonstrate that C/F and aeration are simple and effective techniques to improve membrane contactor performance for nitrogen recovery from the anaerobic digestion centrate.

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Section: Optimization Of the Operating Conditions For The C/f Processcontrasting

confidence: 51%

Impact of Sidestream Pre-Treatment on Ammonia Recovery by Membrane Contactors: Experimental and Economic Evaluation

et al. 2022

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“…Alternatively, since P. aeruginosa could degrade microplastics over time, , a microbial strategy combining the simultaneous aggregation and degradation of microplastics could be developed in the future. While bioflocculation is commonly used to remediate pollutants, such as heavy metals and organic matter, , our work represents the first study to employ experimental evolution to develop bacteria with increased abilities to aggregate microplastics and provides a “release” solution to separate microplastics from bacteria for convenient recovery.…”

Section: Resultsmentioning

confidence: 99%

Microbial–Enzymatic Combinatorial Approach to Capture and Release Microplastics

Chan

Wong

Kwan

et al. 2022

Environ. Sci. Technol. Lett.

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Difficult-to-remove microplastic pollution poses serious risks to ecosystems and human health. Sewage treatment plants also cannot remove microplastics completely with filters or harsh chemical treatments. It is imperative to develop biotechnologies that aggregate microplastics into larger sizes for rapid removal from polluted waters. Using experimental evolution, we generated microplastic aggregators (MAGs) from the environmentally prevalent Pseudomonas aeruginosa, which are evolved to aggregate microplastics into sizable aggregates via biofilm formation. This is mediated by upregulation of a cyclic-di-GMP (c-di-GMP) secondary messenger signaling system found in most bacterial species. Comparative genomic analysis of MAGs revealed mutations in the yfiR gene, which is the repressor of tpbB, a c-di-GMP synthesizing diguanylate cyclase (DGC). Derepression of tpbB conferred MAGs with high intracellular c-di-GMP content and production of a CdrA biofilm matrix protein, resulting in higher biofilm formation and aggregation of microplastics with various sizes and materials. To release microplastics from the aggregates for downstream resource recovery, we employed protease (trypsin) to degrade CdrA and disrupt the biofilm matrix. As a proof-of-concept method, we demonstrated that a capture-then-release approach could mitigate microplastic pollution in seawater samples collected in the vicinity of a sewage outfall. Hence, our work provides insights into efficient biological removal of other micropollutants or biofilm-enabled catalysis of microparticles.

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Removal efficiency of dissolved organic matter from secondary effluent by coagulation-flocculation processes

Cited by 2 publications

References 34 publications

Impact of Sidestream Pre-Treatment on Ammonia Recovery by Membrane Contactors: Experimental and Economic Evaluation

Impact of Sidestream Pre-Treatment on Ammonia Recovery by Membrane Contactors: Experimental and Economic Evaluation

Microbial–Enzymatic Combinatorial Approach to Capture and Release Microplastics

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