The Role of the Pipe-water Interface in DBP Formation and Disinfectant Loss PDF Download

Author: Peter J. Vikesland
Publisher: American Water Works Association
ISBN: 158321044X
Category : Chloramines
Languages : en
Pages : 302

View

Book Description

Author: John E. Dyksen
Publisher: American Water Works Association
ISBN: 1583215352
Category : Water
Languages : en
Pages : 316

View

Book Description
In response to many U.S. water utilities that are considering changing disinfectants from chlorine to alternative disinfectants, this research has been undertaken to gain knowledge of long-term effects.

Author: Peter J. Vikesland
Publisher: American Water Works Association
ISBN: 158321478X
Category :
Languages : en
Pages : 168

View

Book Description
Chloramines are widely used to maintain a disinfectant residual in water distribution systems, but can result in nitrification. This research documents the effectiveness of free chlorine for the control of nitrifying bacteria, evaluates the effect of pipe materials on nitrifying bacteria, and determines how DPBs change as a result of the switch to free chlorine.

Author: Hé́lène Baribeau
Publisher: American Water Works Association
ISBN: 1583214100
Category : Water
Languages : en
Pages : 324

View

Book Description
Assesses the impact of dynamic water quality conditions in the distribution system on the inactivation of microorganisms in bulk water. Addresses questions about the usefulness of maintaining a secondary residual and the target level to be maintained. Bridges research related to distribution system water quality with that of microbial inactivation.

Author: Gregory J. Kirmeyer
Publisher: American Water Works Association
ISBN: 9781583213315
Category : Nature
Languages : en
Pages : 278

View

Book Description
This manual recommends optimal operational criteria for chloramine application to enhance and protect distribution system water quality. It examines the chemical characteristics of chloramines, documents the use of chloramines with case studies, and provides planning, design, startup, and monitoring strategies for optimizing the use of chloramines.

Author: J. Clement
Publisher: American Water Works Association
ISBN: 184339913X
Category : Science
Languages : en
Pages : 132

View

Book Description
There are two groups of specialists involved in the development and application of water quality models, each of which have a different perspective on the use of models: Academics and scientists - chemistry specialists and microbiologists who develop the models. Practitioners - modelers and distribution engineers who use them to solve problems. There are limitations and constraints in the characterization of the underlying processes and the practical application of models to distribution networks, which require further research. The objectives of the research were to characterize the current state of predictive distribution system water quality models and to identify critical research needs for their improvement. The project reviewed both the development and application of models. The report is intended to both steer future research and to act as a general reference on water quality modeling. The report combines a literature review with the practical experience of the project team. The content of a draft report was discussed at an international workshop attended by academics, engineers, scientists, and hydraulic modelers with the objective of agreeing on specific research needs necessary to improve predictive modeling for water quality in distribution systems. The conclusions of the report are derived from the workshop and form the basis of 11 specific research briefs that have been submitted to AwwaRF for consideration of funding. Researchers often focus on modeling the individual processes that control water quality rather than fully modeling water quality throughout distribution systems. For these "process models" to be applied to real distribution networks, they need to be extended to take in account the physical characteristics of the system?the special and temporal variations in flow, velocity and water age, and the effects of mixing water that has traveled along different flow paths.

Author: Michael J. MacPhee
Publisher:
ISBN:
Category : Political Science
Languages : en
Pages : 216

View

Book Description
Offering a high-level view of key distribution system water quality issues that utilities will confront in the coming decades, and a new view of an integrated treatment process, this book covers such topics as microbial regrowth and recontamination, risks associated with release of trace metals from system scale, and impacts of secondary disinfection practices. This resource targets water utility managers, water quality professionals, policy makers, regulators, consultants, and educators.

Author: AWWA Staff
Publisher: American Water Works Association
ISBN: 1613000294
Category : Denitrification
Languages : en
Pages : 288

View

Book Description
This brand new manual was written because of the increased use of chloramine as a residual disinfectant in drinking water distribution systems and the ubiquitous presence of nitrifying bacteria in the environment. Chapters cover background information on the occurrence and microbiology of nitrification in various water environments and provide current practical approaches to nitrification prevention and response. This manual provides a compendium of the current state-of-the-art knowledge, however with quickly developing new advances in nitrification, more writings will be forthcoming. Each chapter can be read independently.

Author:
Publisher:
ISBN:
Category : Books
Languages : en
Pages : 1872

View

Book Description

Author: Sandhya Rao Poleneni
Publisher:
ISBN:
Category :
Languages : en
Pages : 154

View

Book Description
Disinfection is a vital part of a drinking water treatment process and chlorine is the most widely used disinfectant in the world. Though known for its effectiveness, usage of chlorine does lead to the formation of carcinogens which are commonly called Disinfection By-Products (DBPs).With the introduction of the StageII Disinfectant and Disinfection By-Product (D/DBP) regulations, water utility systems must be increasingly cognizant of water quality as it progresses through the supply system and ultimately reaches customers. This study is performed in an effort to develop a simple, non-invasive and cost-effective technology that will effectively lower organic precursors by having water utilities reuse their treatment residuals. Jar tests are used to simulate drinking water treatment processes with coagulants - Aluminum Sulfate (Alum), PolyAluminum Chloride (PACl) and Ferric Chloride and their residuals. Ten Coagulant-to-Residual (C/R) ratios are tested with water from the Missouri River and alluvial ground waters. This treatment results in heavier floc formation and leads to improved sedimentation of organics and additional removal of Aluminum and Iron. An average of 21[percent], 28[percent] and 33[percent] additional TOC removal can be achieved with C/R ratios [less than] 1 with Alum, PACl and Ferric chloride respectively. This study will also focus on determining whether the addition of residual affects chlorine demand, chlorine residual, decay rates, and DBP formation. To simulate the DBP formation and chlorine decay kinetics in small-scale distribution systems, water treated with various coagulants and coagulant to residual ratios was tested in a jar-type simulated distribution system. The TTHM formation over time is at least 35[percent] higher on day 0, 39[percent] higher on day 1 and 47[percent] higher on day 3 in all systems when treated only with coagulants versus when treated with residuals at best C/R ratios irrespective of what coagulant used. It can also be seen that higher (at least 42[percent]) residual concentration can be maintained on day 3 in all water systems when treated with residuals at best C/R ratios versus when treated with only coagulants. Increase in turbidity doesn’t always result in increase in TOC when treated with coagulants and vice versa when treated with residuals at best C/R ratios. TOC, TTHM and chlorine residual follow the pattern of increasing and decreasing with each other and with type of treatment (C/R ratios and coagulants) while turbidity doesn’t irrespective of the coagulant used. Compliance also requires a better understanding of reaction kinetics changes and wall effects with different materials used in the distribution system.To validate our results in full scale distribution system physical conditions, effect of different materials, wall effects, bulk reactions and water movement is analyzed using Simulated Distribution System (SDS) tests, Material Specific Simulated Distribution System (MS-SDS) tests Pipe Loop and Pipe Section Reactor (PSR); all built using materials from City of Columbia distribution system.On an average, just the choice of pipe materials such as PVC and Iron can account for as much as 36 [percent] difference in TTHM formation and 60[percent] difference in chlorine residual decay over time irrespective of the prediction model and operational strategy used.In case of Iron, PE is [less than] 1, leading us to conclude that in the iron pipe systems there is a net loss of TTHM yield due to non-TTHM forming chlorine demand imposed by the pipe environment, whereas in PVC pipe, PE is [greater than] 1.