Sulfide control in sewers by intermittently dosing ... · –Microbiology: Frances Slater, Ahmad...
Transcript of Sulfide control in sewers by intermittently dosing ... · –Microbiology: Frances Slater, Ahmad...
Sulfide control in sewers by intermittently dosing acidified nitrite: from scientific
discovery to application
Zhiguo Yuan
Co-authors
• Guangming Jiang - Advanced Water Management
Centre, The University of Queensland, Australia
• Tony Keating - UniQuest Pty Limited, The University of
Queensland, Australia
• Shaun Corrie - CWE Corrie Water and Environment,
Australia
• Lam Nguyen - US Peroxide, USA
• Kelly O’Halloran - Gold Coast City Council, Australia
2
Water Corp, WA
SA Water
Veolia Water Aus
W Q R A
Barwon Water Melbourne Water
South East Water
Sydney Water
CH2M Hill
Hunter Water
Gold Coast Water
All Australia’s largest water utilities US: DC Water, WERF Europe: Aquafin
Uni QLD
Yarra Valley Water
Actew
The SCORe Project Qld Urban Utilities
Curtin Uni Tech
Background
• Corrosion and odour are major issues for sewer management
• Chemical dosing is a commonly used mitigation strategy
– MHL, iron salts, nitrate and oxygen
– 24/7
• Intermittent dosing is desirable
– pH shock
– Effective, low costs, environmentally benign
4
5
Free nitrous acid (FNA)
HNO2 «NO2
- +H +
pKa=3.398 @ 25oC
100 mgNO2—N/L 0.26 mg HNO2-N/L
@ pH 6.0
0.35 mgNO2—N/L 0.001 mg HNO2-N/L
@ pH 6.0
FNA(mgHNO2-N/L)
0.000 0.005 0.010 0.015 0.020 0.025 0.030
% N
H4
+-N
co
nsu
mp
tio
n
0
20
40
60
80
100
pH=7.0
pH=7.5
pH=8.0
pH=6.5
100%*e- 451.2*x
R2=0.9409
FNA at ppb levels is inhibitory to a broad range of microorganisms
1.7 ppb (equivalent 0.6 mgNO2-N @ pH 6) Ye et al. (2010)
7
What if we increase the FNA concentration by 100 times (to sub-ppm levels)? Can we kill cells in sewer biofilms?
Biocidal effect revealed in sewer reactors
8
Jiang et al., (2011a,b)
7 days
Synergistic effects of FNA and H2O2
9
Jiang et al., (2013)
Cloevis
A proprietary mix of chemicals
Kills 99% of bacteria in laboratory trials Proven in field trials to stop sulfide production
Intermittent, once-a-week dosing
Cloevis: Field trial in Gold Coast, Australia
Cloevis: Field trial in Gold Coast, Australia - Dosing, control, and monitoring
Chemicals & dosing rigs
Mix pump
pH probe
etc.
Computer
D 150 mm
S::CAN unit
1080 m
Odalog
(H2S gas)
Cloevis: Field trial in Gold Coast, Australia
Jiang et al., (2013)
Methane control
14
Jiang et al., (2010)
Economic Analysis
Environmental effects
Improved wastewater treatment processes
Biodegradable Little change to existing infrastructure and progressive roll-out
LOW RISK
16
On-going work
• Commercial trials in Australia and in the US
• Other applications (e.g. sludge treatment)
• Mechanism studies
Acknowledgements • All FNA team members – past and present
– BNR: Vel Vadivelu, Yan Zhou, Maite Pijuan, Liu Ye
– Sewer: Janani Mohanakrishnan, Oriol Gutierrez, Guangming Jiang
– Sludge: Qilin Wang, Liu Ye, Maite Pijuan
– Membrane: Marc Pidou, Pengzhe Sui, Ludwika Nieradzik
– Microbiology: Frances Slater, Ahmad Rosli, Phil Bond
– Commercialisation: Tony Keating, Howard Leemon, Shaun Corrie
• ARC and utility partners for funding
• USP as a commercial partner
• GCCC for assisting with field testing