Reversing clogging in Imhoff tanks by catalyzed hydrogen peroxide treatment

Lee Boon Sing; MohdTaufik Salleh; Chua Bing Guan; Mohamed Haniffa Abdul Hamid; Abdul Kadir Mohd Din

doi:10.2166/wpt.2015.042

Reversing clogging in Imhoff tanks by catalyzed hydrogen peroxide treatment

Water Practice & Technology ◽

10.2166/wpt.2015.042 ◽

2015 ◽

Vol 10 (2) ◽

pp. 355-360

Author(s):

Lee Boon Sing ◽

MohdTaufik Salleh ◽

Chua Bing Guan ◽

Mohamed Haniffa Abdul Hamid ◽

Abdul Kadir Mohd Din

Keyword(s):

Hydrogen Peroxide ◽

Full Scale ◽

Innovative Approach ◽

Filter Media ◽

Hydrogen Peroxide Treatment

One of the most frequently encountered operational problems with Imhoff tanks is filter media clogging. Traditionally, the restoration procedure is to remove the clogged rock media and replace them with clean material. This is costly and may require the facility to close for a time. Recently, an innovative approach has been tested at lab- and full-scale. It consisted of aggressive oxidation and segregation of the clogged solids, using catalyzed hydrogen peroxide. The results indicate that, after treatment, clogging was substantially reduced. The outcomes of the lab- and full-scale studies are discussed in this paper.

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Cyanobacterial and microcystins dynamics following the application of hydrogen peroxide to waste stabilisation ponds

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-10-2067-2013 ◽

2013 ◽

Vol 10 (2) ◽

pp. 2067-2088

Author(s):

D. J. Barrington ◽

A. Ghadouani ◽

G. N. Ivey

Keyword(s):

Hydrogen Peroxide ◽

Full Scale ◽

Management Technique ◽

Waste Stabilization Ponds ◽

Waste Stabilisation Ponds ◽

Hydrogen Peroxide Treatment ◽

Waste Stabilization ◽

Cyanobacterial Species ◽

Treatment Train ◽

Term Management

Abstract. Cyanobacteria and cyanotoxins are a risk to human and ecological health, and a hindrance to biological wastewater treatment. This study investigated the use of hydrogen peroxide (H2O2) for the removal of cyanobacteria and cyanotoxins from within waste stabilization ponds (WSPs). The daily dynamics of cyanobacteria and microcystins (a commonly occurring cyanotoxin) were examined following the addition of H2O2 to wastewater within both the laboratory and at the full-scale within a WSP. Hydrogen peroxide treatment at concentrations ≥ 10−4 g H2O2 μg−1 of total phytoplankton chlorophyll a led to the death of cyanobacteria, in turn releasing intracellular microcystins to the dissolved state. In the full-scale trial, dissolved microcystins were then degraded to negligible concentrations by H2O2 and environmental processes within five days. A shift in the phytoplankton assemblage towards beneficial chlorophyta species was also observed within days of H2O2 addition. However, within weeks, the chlorophyta population was significantly reduced by the re-establishment of toxic cyanobacterial species. This re-establishment was likely due to the inflow of cyanobacteria from ponds earlier in the treatment train, suggesting that whilst H2O2 may be a suitable short-term management technique, it must be coupled with control over inflows if it is to improve WSP performance in the longer term.

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Cyanobacterial and microcystins dynamics following the application of hydrogen peroxide to waste stabilisation ponds

Hydrology and Earth System Sciences ◽

10.5194/hess-17-2097-2013 ◽

2013 ◽

Vol 17 (6) ◽

pp. 2097-2105 ◽

Cited By ~ 10

Author(s):

D. J. Barrington ◽

A. Ghadouani ◽

G. N. Ivey

Keyword(s):

Hydrogen Peroxide ◽

Wastewater Treatment ◽

Treatment Plant ◽

Full Scale ◽

Management Technique ◽

Waste Stabilization Ponds ◽

Waste Stabilisation Ponds ◽

Hydrogen Peroxide Treatment ◽

Waste Stabilization ◽

Treatment Train

Abstract. Cyanobacteria and cyanotoxins are a risk to human and ecological health, and a hindrance to biological wastewater treatment. This study investigated the use of hydrogen peroxide (H2O2) for the removal of cyanobacteria and cyanotoxins from within waste stabilization ponds (WSPs). The daily dynamics of cyanobacteria and microcystins (commonly occurring cyanotoxins) were examined following the addition of H2O2 to wastewater within both the laboratory and at the full scale within a maturation WSP, the final pond in a wastewater treatment plant. Hydrogen peroxide treatment at concentrations ≥ 0.1 mg H2O2 μg−1 total phytoplankton chlorophyll a led to the lysis of cyanobacteria, in turn releasing intracellular microcystins to the dissolved state. In the full-scale trial, dissolved microcystins were then degraded to negligible concentrations by H2O2 and environmental processes within five days. A shift in the phytoplankton assemblage towards beneficial Chlorophyta species was also observed within days of H2O2 addition. However, within weeks, the Chlorophyta population was significantly reduced by the re-establishment of toxic cyanobacterial species. This re-establishment was likely due to the inflow of cyanobacteria from ponds earlier in the treatment train, suggesting that whilst H2O2 may be a suitable short-term management technique, it must be coupled with control over inflows if it is to improve WSP performance in the longer term.

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