Optimization of coagulation-flocculation parameters using a photometric dispersion analyser

Ramphal, S.; Sibiya, M. S.

doi:10.5194/dwesd-7-95-2014

Cited by 2 publications

(2 citation statements)

References 16 publications

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“…The chemical sludge was separated by gravitational sedimentation for 120 min. The flocculation parameters were set through jar test optimisations on the processed wastewater [37,38].…”

Section: Methodsmentioning

confidence: 99%

Tertiary Treatment of Livestock Wastewater in the Context of Alternative Water Resources for Sustainable Agriculture

Tociu¹,

Cristina²,

Deák³

et al. 2020

Rev. Chim.

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The limited availability and quality of water resources are key issues of water management, and the protection and preservation of water resources are a requirement in the context of accelerated economic growth and principles of sustainable development. The experimental research presented in this paper is based on the need to identify alternative water sources and support unconventional wastewater treatment methods which would enable their reuse in areas affected by water scarcity and drought. Livestock wastewater contain significant levels of nutrients (nitrogen and phosphorus) and may represent an attractive water source for crop irrigation. This paper evaluates the efficacy of a proposed technological process for tertiary wastewater treatment consisting of two steps: electrochemical treatment for the removal of suspended and colloidal impurities and ozone disinfection. The experimental results showed higher efficiencies for the removal of chemical pollutants (92.5% COD, 79.3% BOD, 98.6% TSS, 41% residue saline) and significant inactivation of microorganisms (over 99.9% for total coliform bacteria and in some cases 100% for faecal coliform bacteria and faecal streptococci). The quality of the effluent complies with the regulations for wastewater use in agriculture and allows its reuse for different categories of use considering the required conditions for soil/crops. The successful application of treated wastewater to agricultural crops depends in a high extent on the good practices aimed on the improvement of crop yield and quality, optimisation of soil productivity and protection of the environment undertaken by the economic entities.

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“…The chemical sludge was separated by gravitational sedimentation for 120 min. The flocculation parameters were set through jar test optimisations on the processed wastewater [37,38].…”

Section: Methodsmentioning

confidence: 99%

Tertiary Treatment of Livestock Wastewater in the Context of Alternative Water Resources for Sustainable Agriculture

Tociu¹,

Cristina²,

Deák³

et al. 2020

Rev. Chim.

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“…The practical objective of water treatment process is to obtain sanitary water by extracting pollutants, removing toxicants, eliminating particles, and killing pathogens. This system concept is also used to treat water for specific applications, (Mohammed and Shakir, 2018;Moran, 2018;Ramphal and Sibiya, 2014). Following flocculation, agglomerated particles enter the clarification unit where they are removed by sedimentation or by flotation.…”

Section: The Conventional Water Treatment Processmentioning

confidence: 99%

Effects of configuration and operating conditions on turbidity removal of jet clarifier

Romphophak

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In water treatment, flocculation creates large and weighty flocs enough to be removed by the downstream processes of sedimentation and filtration. Among the various existing technologies, the jet clarifier is considered as an effective and compact system as it couples flocculation and clarification in a single unit. For the design of jet mixing, much experimental work has been done and many correlations have been proposed. However, these correlations are case specifics, and, to date, there is no comprehensive view for the flocculation aspect. In order to evaluate the performance of the jet clarifier for turbidity removal and understand hydrodynamics to propose the optimal operating conditions and design criteria, two different configurations of the continuous jet clarifiers are figured out. The first one is a prototype of a 3D jet clarifier studied at two scales and implemented at Samsen Water Treatment Plant, Thailand; these two reactors were designed to investigate the performance and mean Residence Time Distribution (RTD) for various injected flow rates. The results indicated no effect of reactor sizes, and a reduction of the initial turbidity (50 NTU) was achieved with an efficiency of approximately 80% under optimal conditions. Moreover, the second jet clarifier configuration was designed as a Quasi-2Dimensional (Q2D) jet clarifier at the TBI-INSA-Toulouse, France allowing the application of optical metrological methods used to understand better local phenomena controlling the efficiency of the jet clarifier. Hence, measurements of instantaneous velocity field were performed by means of Particle Image Velocimetry (PIV). The processing of experimental PIV data highlighted a strong circulation induced by the jet in the flocculation zone. At this location, the range of velocity gradient (G) is 3 to 13 s-1 whereas the residence time decreases from 4 to 1 hour. Based on the hydrodynamic analysis, the Camp number (Gt) in the flocculation zone is shown to be constant at around 7,000 for different jet flow rates (from 11L/hr to 49L/hr). The efficiency of such the jet clarifier can thus be foreseen. Plus, measurements of the number of flocs and their size distributions were performed by means of shadowgraphy and image analysis. Thanks to a coupling between the different experimental results obtained in the Q2D jet clarifier, it was possible to relate the evolution of the number of flocs along the jet to the recirculation loop present in the flocculation zone. The relative independence of the floc size distributions on the flow rate is discussed in light of the Camp number, which can explain the efficiency of the jet clarifier in terms of flocculation. Finally, due to reactor design, the simulations using CFD code showing encouraging results were presented at the end of the manuscript. Here as well, characteristic time scales and velocity gradient were used to perform the first comparisons.

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Optimization of coagulation-flocculation parameters using a photometric dispersion analyser

Cited by 2 publications

References 16 publications

Tertiary Treatment of Livestock Wastewater in the Context of Alternative Water Resources for Sustainable Agriculture

Tertiary Treatment of Livestock Wastewater in the Context of Alternative Water Resources for Sustainable Agriculture

Effects of configuration and operating conditions on turbidity removal of jet clarifier

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