Recovery and Reuse of Iron Coagulants in Water Treatment

Pigeon, Paul; Linstedt, K. Daniel; Bennett, Edwin R.

doi:10.1002/j.1551-8833.1978.tb04200.x

Cited by 7 publications

(3 citation statements)

References 3 publications

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“…As these options become more established, the marginal benefit of recycling coagulants is diminished, potentially making the return on the initial capital investment for CR harder to achieve during its operational lifetime. Bishop et al (1987); c) Chen et al (1976); d) Dymaczewski et al (1997); e) Elliott et al (1990); f) Gallimore et al (1999); g) Georgantas and Grigoropoulou (2005); h) Godbold et al (2003); i) Jimenez et al (2007); j) King et al (1975); k) Lindsey and Tongkasame (1975); l) Petruzzelli et al (2000); m) Pigeon et al (1978); n) Prakash and Sengupta (2004); o) Sengupta (1994) (Zhao et al, 2009). Removals of 73% for chemical oxygen demand (COD), 83% for biological oxygen demand (BOD 5 ), 86% for reactive P, 89% for soluble reactive P, and 78% for suspended solids (SS) were found.…”

Section: Sludge Characteristics and Contentmentioning

confidence: 99%

“…Sodium sulfide has been used to reduce the oxidation state of ferric salts to ferrous, reducing the acid:metal molar ratio to 1:1. The settled volume of the remaining insoluble fraction was reduced to 20% of the original (Pigeon et al, 1978). However, removal of residual sulfide was required before the recovered coagulant could be reused, to prevent iron sulfide formation (Pigeon et al, 1978).…”

Section: Solubilizationmentioning

confidence: 99%

“…The settled volume of the remaining insoluble fraction was reduced to 20% of the original (Pigeon et al, 1978). However, removal of residual sulfide was required before the recovered coagulant could be reused, to prevent iron sulfide formation (Pigeon et al, 1978). The demand for costly sodium sulfide by this process also significantly compromises the cost benefit.…”

Section: Solubilizationmentioning

confidence: 99%

See 2 more Smart Citations

Coagulant Recovery from Water Treatment Residuals: A Review of Applicable Technologies

Keeley

Jarvis

Judd

2014

Critical Reviews in Environmental Science and Technology

127

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Section: Sludge Characteristics and Contentmentioning

confidence: 99%

Section: Solubilizationmentioning

confidence: 99%

Section: Solubilizationmentioning

confidence: 99%

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Coagulant Recovery from Water Treatment Residuals: A Review of Applicable Technologies

Keeley

Jarvis

Judd

2014

Critical Reviews in Environmental Science and Technology

127

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Organic Contaminant Removal by Coagulation and Related Process Combinations

Randtke¹

1988

Journal AWWA

217

119

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This article synthesizes work done over the past few decades to better understand the removal of organic contaminants by the coagulation process, alone and in combination with other processes. Published data demonstrate that coagulation can substantially reduce the concentration of certain organic contaminants found in drinking water supplies, and that an understanding of the fundamental mechanisms by which coagulation removes organic contaminants facilitates qualitative prediction of the types of contaminants likely to be removed and the effects of process control variables. Data also demonstrate that removal of organic contaminants by coagulation can be influenced by other processes, such as preozonation, and that coagulation can influence the removal of organic contaminants by subsequent treatment processes, such as filtration and activated carbon adsorption.

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Conversion of coal mine drainage ochre to water treatment reagent: Production, characterisation and application for P and Zn removal

Sapsford

Santonastaso

Thorn³

et al. 2015

Journal of Environmental Management

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Coal mine drainage ochre is a ferruginous precipitate that forms from mine water in impacted watercourses and during treatment. With thousands of tonnes per annum of such ochre arising from mine water treatment in the UK alone, management of these wastes is a substantive issue. This paper demonstrates that the ochre from both active and passive treatment of coal mine drainage can be transformed into an effective water treatment reagent by simple acid dissolution and that the reagent can be used for the removal of dissolved phosphorous from municipal wastewater and zinc from non-coal mine waters. Ochre is readily soluble in H2SO4 and HCl. Ochre is more soluble in HCl with solubilities of up to 100 g/L in 20% (w/w) HCl and 68 g/L in 10% (w/w) H2SO4. For four of the eight tested ochres solubility decreased in higher concentrations of H2SO4. Ochre compositional data demonstrate that the coal mine ochres tested are relatively free from problematic levels of elements seen by other authors from acid mine drainage-derived ochre. Comparison to British Standards for use of iron-based coagulants in drinking water treatment was used as an indicator of the acceptability of use of the ochre-derived reagents in terms of potentially problematic elements. The ochre-derived reagents were found to meet the 'Grade 3' specification, except for arsenic. Thus, for application in municipal wastewater and mine water treatment additional processing may not be required. There was little observed compositional difference between solutions prepared using H2SO4 or HCl. Ochre-derived reagents showed applicability for the removal of P and Zn with removals of up to 99% and 97% respectively measured for final pH 7-8, likely due to sorption/coprecipitation. Furthermore, the results demonstrate that applying a Fe dose in the form of liquid reagent leads to a better Fe:P and Fe:Zn removal ratio compared to ochre-based sorption media tested in the literature.

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Recovery and Reuse of Iron Coagulants in Water Treatment

Abstract: Motivated by the difficulties and costs involved in sludge disposal, a laboratory study investigated a combined acidification-sulfide reduction method for recovering iron from water treatment plant sludge.

Cited by 7 publications

References 3 publications

Coagulant Recovery from Water Treatment Residuals: A Review of Applicable Technologies

Coagulant Recovery from Water Treatment Residuals: A Review of Applicable Technologies

Organic Contaminant Removal by Coagulation and Related Process Combinations

Conversion of coal mine drainage ochre to water treatment reagent: Production, characterisation and application for P and Zn removal

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