Previous research has shown that reducing the amount of particulate matter in potable water can reduce the risk of human pathogens such as Cryptosporidium parvum entering drinking supplies. Although particle counters are a powerful tool in the amount and specificity of information they produce compared with traditionally used turbidimeters, the UK water industry has so far remained relatively cautious in embracing this new technology. This is because much doubt still remains over the value and practical use of these monitors.
The paper summarises three areas in which particle counters have been beneficial, utilising (a) their higher sensitivity to changes in water quality at low turbidities (below 0.1 NTU), (b) their higher sensitivity to changes associated with larger particle sizes, and (c) their particle-sizing ability. In general, particle counters are best used as an optional process research/optimisation tool: turbidimeters remain the preferred monitor for process control.