Project Appreciation and Objectives
Small, portable kits are used widely in water treatment for the analysis of key water quality parameters. The applications include: validation of on-line measurements (pH, chlorine, turbidity); infrequent measurements to either confirm process performance (e.g. manganese, aluminium, iron) where on-line monitoring is not present or unreliable, or to confirm that chemical dose is correct (e.g. phosphate for plumbosolvency control). Test kits have also become available for measurands (e.g. THMs) for which on-line monitoring is not feasible and where off-site analysis is expensive and has too long a response time to be of use for process control purposes. In addition certain regulatory measurements (e.g. turbidity) could be better made on-site, and the potential for using portable kits to facilitate this needs to be explored.
This project is reviewing the cost, availability and performance of test kits for key water quality parameters. The work is also examining the potential for using tests kits for certain parameters to produce measurements for regulatory purposes.
Benefits to Clients
Help identify changes in treatment performance that could risk compliance failure.
- For certain parameters, most notably THM's
- improve process control by providing more immediate results.
- Accurate validation of on-line measurements used in feedback control to ensure correct chemical dosing (e.g. chlorine, phosphate).
The following two phases are proposed:
- In consultation with the project Liaison Group, identify key measurands of interest together with application (e.g. measurement range, sample type).
- Identify and select equipment to assess and obtain loan of equipment for laboratory evaluation. The situation with regard to making regulatory measurements on site will be determined.
- Develop a methodology to assess the analytical performance of specific instruments. This will include analysis of real and synthetic samples to ensure as wide a range of application as possible is covered. Equipment selected for testing will be tested using this methodology.
Concise guide setting out the cost, capability and applicability of the range of test kits that are on the market. The guide will contain the results of controlled analytical tests, plus guidance for the industry of what else is needed.
Related WRc Work
- Review of on-line water quality monitoring strategy for a major utility, 2004.
- Production of instrument handbooks for key water quality measurands (chlorine, turbidity, ammonia, pH, Al, Fe, Mn).