Effects of operational conditions on sludge degradation and organic acids formation in low-critical wet air oxidation

Chung, Jinwook; Lee, Mi-Kyung; Ahn, Jaehwan; Bae, Wookeun; Lee, Yong-Woo; Shim, Hyungbo

doi:10.1016/j.jhazmat.2008.05.038

Cited by 73 publications

(25 citation statements)

References 15 publications

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“…The data obtained are in good agreement with outcomes available in the literature [19,23] and indicate a common trend of removal efficiencies. In particular, the limiting conditions of the operating parameters are highlighted: after a strict initial dependence of WO performance as a function of temperature and reaction time, at higher parameter values the operating conditions become less limiting and therefore a lower increase of process efficiency is observed (variation of the curve slope).…”

Section: Results and Discussion Lab-scale Wet Oxidation Pilot Plantsupporting

confidence: 89%

Wet Oxidation as an Advanced and Sustainable Technology for Sludge Treatment and Management: Results from Research Activities and Industrial-Scale Experiences

Slavik¹,

Galessi²,

Rapisardi³

et al. 2015

Drying Technology

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In this article, the effectiveness of an advanced sludge treatment technology (Wet Oxidation, WO) is presented by analyzing experimental studies at the lab scale and data collected during years of industrial-scale activities. The data showed good performances of WO on COD and VSS removal efficiencies-about 65-70% and 95-98%, respectively-and the effect of operating parameters (i.e., temperature and reaction time) on process efficiencies was highlighted. The energy balance of the WO systems indicated that about 90% of the energy entering the system may be recovered. Finally, a techno-economic assessment showed that WO can be a suitable solution for sludge treatment and minimization.

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Section: Results and Discussion Lab-scale Wet Oxidation Pilot Plantsupporting

confidence: 89%

Wet Oxidation as an Advanced and Sustainable Technology for Sludge Treatment and Management: Results from Research Activities and Industrial-Scale Experiences

Slavik¹,

Galessi²,

Rapisardi³

et al. 2015

Drying Technology

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“…In a previous study it was demonstrated that the SCOD released during SAS disintegration was composed of proteins (30%), carbohydrates (13%) and VFAs (12%) but the remaining 45% of the SCOD was not characterised [16]. Other studies have also identified SCOD as the main product [22] that could be fractionated into proteins, extracellular polymeric substances and soluble microbial products after ultrasound [23,24] or thermal treatment [25], but the identification of the com- plete range of substances that contribute to SCOD has not yet been described.…”

Section: Soluble Cod and Vfas Productionmentioning

confidence: 99%

Comparison between disintegrated and fermented sewage sludge for production of a carbon source suitable for biological nutrient removal

Soares

Kampas

Maillard

et al. 2010

Journal of Hazardous Materials

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There is a need to investigate processes that enable sludge re-use while enhancing sewage treatment efficiency. Mechanically disintegrated thickened surplus activated sludge (SAS) and fermented primary sludge were compared for their capacity to produce a carbon source suitable for BNR by completing nutrient removal predictive tests. Mechanically disintegration of SAS using a deflaker enhanced volatile fatty acids (VFAs) content from 92 to 374 mg l(-1) (4.1-fold increase). In comparison, primary sludge fermentation increased the VFAs content from 3.5 g l(-1) to a final concentration of 8.7 g l(-1) (2.5-fold increase). The carbon source obtained from disintegration and fermentation treatments improved phosphate (PO(4)-P) release and denitrification by up to 0.04 mg NO(3)-Ng(-1)VSS min(-1) and 0.031 mg PO(4)-Pg(-1)VSS min(-1), respectively, in comparison to acetate (0.023 mg NO(3)-Ng(-1)VSS min(-1)and 0.010 mg PO(4)-Pg(-1)VSS min(-1)). Overall, both types of sludge were suitable for BNR but disintegrated SAS displayed lower carbon to nutrient ratios of 8 for SCOD:PO(4)-P and 9 for SCOD:NO(3)-N. On the other hand, SAS increased the concentration of PO(4)-P in the settled sewage by a further 0.97 g PO(4)-P kg(-1)SCOD indicating its potential negative impact towards nutrient recycling in the BNR process.

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“…In this process, the pollutants are oxidized by oxygen to carbon dioxide, water, and other products without the emissions of nitrogen oxides, sulfur dioxide, hydrogen chloride, dioxins [ 12 ]. Therefore, WAO is an interesting alternative for the solubilisation and mineralization of activated sludge [ 13 – 15 ]. Lab-scale and industrial-scale experiences have confirmed the good performance of WAO on volatile suspended solids (VSS) and chemical oxygen demand (COD) removal [ 16 ].…”

Section: Introductionmentioning

confidence: 99%

Highly efficient degradation of pharmaceutical sludge by catalytic wet oxidation using CuO-CeO2/γ-Al2O3 as a catalyst

2018

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Pharmaceutical sludge is considered as a hazardous material with high treatment and disposal costs. In the present study, the catalytic wet oxidation (CWO) of pharmaceutical sludge by CuO-CeO2/γ-Al2O3 as the catalyst was investigated. The catalyst was prepared by traditional wet impregnation. The catalyst was characterized using X-ray Powder Diffraction (XRD) and Scanning Electron Microscopy (SEM). CWO was performed in an experimental batch reactor. Several parameters that could affect the catalytic degradation efficiency, including catalyst dose, temperature, time, oxygen pressure and pH, were investigated. Under optimum conditions, the highest removal rate of volatile suspended solids (VSS) was 87.3% and was achieved at 260°C for 60 min with an oxygen pressure of 1.0 MPa and 10 g/L of catalyst. At the same time, the chemical oxygen demand (COD) removal rate reached as high as 72.6%. This work implies that catalytic wet oxidation is a promising method for the highly efficient degradation of pharmaceutical sludge.

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Effects of operational conditions on sludge degradation and organic acids formation in low-critical wet air oxidation

Cited by 73 publications

References 15 publications

Wet Oxidation as an Advanced and Sustainable Technology for Sludge Treatment and Management: Results from Research Activities and Industrial-Scale Experiences

Wet Oxidation as an Advanced and Sustainable Technology for Sludge Treatment and Management: Results from Research Activities and Industrial-Scale Experiences

Comparison between disintegrated and fermented sewage sludge for production of a carbon source suitable for biological nutrient removal

Highly efficient degradation of pharmaceutical sludge by catalytic wet oxidation using CuO-CeO2/γ-Al2O3 as a catalyst

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