Particle size distribution analysis of chemically enhanced two‐phase membrane filtration for olive mill effluents

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BACKGROUND The study focused on the biodegradation of pretreated olive mill wastewater (OMW) properly diluted in and mixed with a biodegradable substrate and/or domestic sewage stream. It utilized the permeate of a chemically conditioned two‐stage ultrafiltration/nanofiltration system with COD of 5700 mg L−1 and a total phenol content of 100 mg L−1. Peptone mixture with similar characteristics to domestic sewage was adopted as the biodegradable synthetic substrate. The study relied on two sets of microbial culture; one acclimated to peptone and the other to a mixture of peptone and domestic sewage. Respirometric analyses were conducted on pretreated OMW diluted in the selected substrate using corresponding biomass seeding. RESULTS Model evaluation of the oxygen uptake rate profiles indicated that the pretreated OMW was fully consumed in the respirometric tests. There were no inhibitory/toxic impacts of OMW dosing on the biomass. The entire biomass participated in the utilization of OMW/substrate with no metabolic adjustment problems. CONCLUSION Experimental results provided conclusive evidence that co‐treatment with a domestic sewage stream is a viable option for OMW management, after a chemically conditioned two‐stage filtration used as the pretreatment step. Pretreatment removes the recalcitrant nature of the wastewater, which becomes fully biodegradable under appropriate dilution and mixing conditions. © 2016 Society of Chemical Industry

Section: Resultssupporting

confidence: 89%

Section: Pretreatment Of Olive Mill Wastewatersupporting

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Biodegradation of pretreated olive mill effluent in mixture with a domestic sewage or compatible wastewater stream

Khaligh

Yağcı

Ubay‐Cokgor

et al. 2016

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Particle size distribution of chemical oxygen demand in industrial effluents: impact on effective filtration size and modelling of membrane bioreactors

Doğruel

Orhon

2021

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This study reviews particle size distribution (PSD) analysis for industrial effluents. Evaluation of available experimental data indicated that the approach started with arbitrary selection of size distribution. Following a pioneering study on pulp and paper effluent, sequential filtration and ultrafiltration has established itself as a prescribed methodology complementing respirometric assessment of chemical oxygen demand (COD) fractionation based on biodegradation characteristics. Results indicated that most industrial effluents exhibited a COD distribution where soluble fractions accounted for the majority of the total COD, with significant implications for the understanding of membrane bioreactor (MBR) systems. Observations on the accumulation of soluble COD in the reactor to levels much higher than the permeate COD paved the way to define an experimental PSD methodology for assessing the effective filtration size for the membrane module. This novel parameter considered in the light of reported PSD analyses showed that a portion of what was conventionally considered soluble COD would be retained by the size barrier of the membrane and recycled back to the reactor. Thus, MBR systems require a new mathematical model structure that would include a modified COD fractionation, account for the retained COD fractions as additional model components and utilize related mass balance relationships in order to yield an accurate mechanistic description of microbial reactions taking place in the system.

Anatomy of chemically enhanced sewage settling by particle size distribution analysis

Duba

Sözen

Doğruel

et al. 2022

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BACKGROUND: This study investigated the anatomy of organic carbon (as chemical oxygen demand, COD) removal from sewage through chemically assisted settling, by means of particle size distribution (PSD) analysis: it showed which size fractions were affected, aside from the particulate COD. The experiments were conducted on the effluent of the existing preliminary treatment plant before deep-sea discharge into the Bosphorus. FeCl 3 , alum and polyaluminum chloride (PAC) were used as coagulants at different doses. The performance of the coagulants on the effluent COD was interpreted with PSD.RESULTS: PAC at 25 mg L −1 , selected as the optimum coagulant, reduced COD below soluble COD level, to around 145 mg L −1 , with an overall efficiency of more than 70%. Although chemical settling was most effective on particulate COD at >450 nm, it also provided a COD removal of 28% in 220-450 nm of the colloidal range and 40% in 13-220 nm of the range, representing soluble hydrolysable COD. The lowest removal rate was observed in the soluble range, consisting of readily biodegradable (only 5%) and a part of the inert COD (<2 nm) identified as 12%twice as high as ordinary domestic wastewaters, with only 1%.CONCLUSION: PSD and COD fractionation analyses were instrumental in depicting the potential of chemically enhanced settling to reduce COD in the soluble range, identifying the distribution of remaining COD fractions in different size intervals. The results also suggested a novel treatment process with additional membrane filtration, namely membrane chemical reactor, (MCR), reflecting a potential for replacing the conventional activated sludge process.