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Hossain S, Chow CWK, Cook D, Sawade E, Hewa GA. Review of Nitrification Monitoring and Control Strategies in Drinking Water System. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19074003. [PMID: 35409686 PMCID: PMC8997939 DOI: 10.3390/ijerph19074003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 03/17/2022] [Accepted: 03/23/2022] [Indexed: 12/29/2022]
Abstract
Nitrification is a major challenge in chloraminated drinking water systems, resulting in undesirable loss of disinfectant residual. Consequently, heterotrophic bacteria growth is increased, which adversely affects the water quality, causing taste, odour, and health issues. Regular monitoring of various water quality parameters at susceptible areas of the water distribution system (WDS) helps to detect nitrification at an earlier stage and allows sufficient time to take corrective actions to control it. Strategies to monitor nitrification in a WDS require conducting various microbiological tests or assessing surrogate parameters that are affected by microbiological activities. Additionally, microbial decay factor (Fm) is used by water utilities to monitor the status of nitrification. In contrast, approaches to manage nitrification in a WDS include controlling various factors that affect monochloramine decay rate and ammonium substrate availability, and that can inhibit nitrification. However, some of these control strategies may increase the regulated disinfection-by-products level, which may be a potential health concern. In this paper, various strategies to monitor and control nitrification in a WDS are critically examined. The key findings are: (i) the applicability of some methods require further validation using real WDS, as the original studies were conducted on laboratory or pilot systems; (ii) there is no linkage/formula found to relate the surrogate parameters to the concentration of nitrifying bacteria, which possibly improve nitrification monitoring performance; (iii) improved methods/monitoring tools are required to detect nitrification at an earlier stage; (iv) further studies are required to understand the effect of soluble microbial products on the change of surrogate parameters. Based on the current review, we recommend that the successful outcome using many of these methods is often site-specific, hence, water utilities should decide based on their regular experiences when considering economic and sustainability aspects.
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Affiliation(s)
- Sharif Hossain
- Scarce Resources and Circular Economy (ScaRCE), UniSA STEM, University of South Australia, Mawson Lakes, SA 5095, Australia; (C.W.K.C.); (G.A.H.)
- Correspondence:
| | - Christopher W. K. Chow
- Scarce Resources and Circular Economy (ScaRCE), UniSA STEM, University of South Australia, Mawson Lakes, SA 5095, Australia; (C.W.K.C.); (G.A.H.)
- Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia
| | - David Cook
- South Australian Water Corporation, Adelaide, SA 5000, Australia; (D.C.); (E.S.)
| | - Emma Sawade
- South Australian Water Corporation, Adelaide, SA 5000, Australia; (D.C.); (E.S.)
| | - Guna A. Hewa
- Scarce Resources and Circular Economy (ScaRCE), UniSA STEM, University of South Australia, Mawson Lakes, SA 5095, Australia; (C.W.K.C.); (G.A.H.)
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Shi Y, Babatunde A, Bockelmann-Evans B, Li Q, Zhang L. On-going nitrification in chloraminated drinking water distribution system (DWDS) is conditioned by hydraulics and disinfection strategies. J Environ Sci (China) 2020; 96:151-162. [PMID: 32819689 DOI: 10.1016/j.jes.2020.04.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/30/2020] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
Within the drinking water distribution system (DWDS) using chloramine as disinfectant, nitrification caused by nitrifying bacteria is increasingly becoming a concern as it poses a great challenge for maintaining water quality. To investigate efficient control strategies, operational conditions including hydraulic regimes and disinfectant scenarios were controlled within a flow cell experimental facility. Two test phases were conducted to investigate the effects on the extent of nitrification of three flow rates (Q = 2, 6, and 10 L/min) and four disinfection scenarios (total Cl2=1 mg/L, Cl2/NH3-N=3:1; total Cl2=1 mg/L, Cl2/NH3-N=5:1; total Cl2=5 mg/L, Cl2/NH3-N=3:1; and total Cl2=5 mg/L, Cl2/NH3-N=5:1). Physico-chemical parameters and nitrification indicators were monitored during the tests. The characteristics of biofilm extracellular polymetric substance (EPS) were evaluated after the experiment. The main results from the study indicate that nitrification is affected by hydraulic conditions and the process tends to be severe when the fluid flow transforms from laminar to turbulent (2300<Re<4000). Increasing disinfectant concentration and optimizing Cl2/NH3-N mass ratio were found to inhibit nitrification to some extend when the system was running at turbulent condition (Q = 10 L/min, Re = 5535). EPS extracted from biofilm that was established at the flow rate of 6 L/min had greater carbohydrate/protein ratio. Furthermore, several nitrification indicators were evaluated for their prediction efficiency and the results suggest that the change of nitrite, together with total organic carbon (TOC) and turbidity can indicate nitrification potential efficiently.
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Affiliation(s)
- Yi Shi
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China; Discipline of Civil Engineering, Cardiff University School of Engineering, The Parade, Cardiff, CF24 3AA, UK.
| | - Akintunde Babatunde
- Discipline of Civil Engineering, Cardiff University School of Engineering, The Parade, Cardiff, CF24 3AA, UK; School of Civil Engineering, University of Leeds, Leeds, LS2, 9JT, UK
| | - Bettina Bockelmann-Evans
- Discipline of Civil Engineering, Cardiff University School of Engineering, The Parade, Cardiff, CF24 3AA, UK
| | - Qijie Li
- Discipline of Civil Engineering, Cardiff University School of Engineering, The Parade, Cardiff, CF24 3AA, UK
| | - Liang Zhang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China
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Scott DB, Van Dyke MI, Anderson WB, Huck PM. Influence of water quality on nitrifier regrowth in two full-scale drinking water distribution systems. Can J Microbiol 2015; 61:965-76. [PMID: 26518069 DOI: 10.1139/cjm-2015-0375] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The potential for regrowth of nitrifying microorganisms was monitored in 2 full-scale chloraminated drinking water distribution systems in Ontario, Canada, over a 9-month period. Quantitative PCR was used to measure amoA genes from ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and these values were compared with water quality parameters that can influence nitrifier survival and growth, including total chlorine, ammonia, temperature, pH, and organic carbon. Although there were no severe nitrification episodes, AOB and AOA were frequently detected at low concentrations in samples collected from both distribution systems. A culture-based presence-absence test confirmed the presence of viable nitrifiers. AOB were usually present in similar or greater numbers than AOA in both systems. As well, AOB showed higher regrowth potential compared with AOA in both systems. Statistically significant correlations were measured between several water quality parameters of relevance to nitrification. Total chlorine was negatively correlated with both nitrifiers and heterotrophic plate count (HPC) bacteria, and ammonia levels were positively correlated with nitrifiers. Of particular importance was the strong correlation between HPC and AOB, which reinforced the usefulness of HPC as an operational parameter to measure general microbiological conditions in distribution systems.
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Affiliation(s)
- Daniel B Scott
- NSERC Chair in Water Treatment, Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.,NSERC Chair in Water Treatment, Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Michele I Van Dyke
- NSERC Chair in Water Treatment, Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.,NSERC Chair in Water Treatment, Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - William B Anderson
- NSERC Chair in Water Treatment, Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.,NSERC Chair in Water Treatment, Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Peter M Huck
- NSERC Chair in Water Treatment, Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.,NSERC Chair in Water Treatment, Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
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Bal Krishna KC, Sathasivan A, Chandra Sarker D. Evidence of soluble microbial products accelerating chloramine decay in nitrifying bulk water samples. WATER RESEARCH 2012; 46:3977-3988. [PMID: 22695354 DOI: 10.1016/j.watres.2012.05.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 05/10/2012] [Accepted: 05/14/2012] [Indexed: 06/01/2023]
Abstract
The discovery of a microbially derived soluble product that accelerates chloramine decay is described. Nitrifying bacteria are believed to be wholly responsible for rapid chloramine loss in drinking water systems. However, a recent investigation showed that an unidentified soluble agent significantly accelerated chloramine decay. The agent was suspected to be either natural organic matter (NOM) or soluble microbial products (SMPs). A laboratory scale reactor was fed chloraminated reverse osmosis (RO) treated water to eliminate the interference from NOM. Once nitrification had set in, experiments were conducted on the reactor and feed waters to determine the identity of the component. The study showed the presence of SMPs released by microbes in severely nitrified waters. Further experiments proved that the SMPs significantly accelerated chloramine decay, probably through catalytic reaction. Moreover, application of common protein denaturing techniques stopped the reaction implying that the compound responsible was likely to be a protein. This significant finding will pave the way for better control of chloramine in the distribution systems.
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Affiliation(s)
- K C Bal Krishna
- Department of Civil and Construction Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
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Rahman MS, Encarnacion G, Camper AK. Nitrification and potential control mechanisms in simulated premises plumbing. WATER RESEARCH 2011; 45:5511-5522. [PMID: 21880342 DOI: 10.1016/j.watres.2011.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 07/19/2011] [Accepted: 08/07/2011] [Indexed: 05/31/2023]
Abstract
Indigenous drinking water organisms were used to establish nitrification in glass reactors containing copper or polyvinyl chloride (PVC) surfaces. The reactors were fed soil-derived humics as the organic carbon source and ammonium sulfate as the nitrogen source in biologically treated tap water. Water in the reactors was stagnant for 8 h and then flowed for 5 min to simulate conditions in household plumbing. Following the establishment of complete nitrification (conversion of ammonia to nitrate) in both reactor types, various inhibitors of nitrification were tested followed by a period where recovery of nitrification was observed. In one PVC reactor, copper was gradually introduced up to 1.3 ppm. To ensure that most of the copper was in the ionic form, the pH of the influent was then gradually lowered to 6.6. No significant change in nitrification was observed in the presence of copper. Chlorite was introduced into copper and PVC reactors at doses increasing from 0.2 ppm to 20 ppm. There was limited effect on the PVC system and inhibition in the copper reactor only at 20 ppm. Chloramine was tested at chlorine to ammonia ratios ranging from 0.5:1 to 5:1. Nitrification activity was impacted significantly at a 5:1 ratio and ultimately stopped, with the fastest response being in the copper system. Whenever a control mechanism was tested, there was increased release of copper from the reactors with copper coupons. In all cases, nitrification recovered when inhibitors were removed but the rates of recovery differed depending on the treatment method and coupon surface.
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