Water; recovery, reclamation and recycling within the Irish dairy industry

Since the abolition of EU Milk quotas in April 2015, milk production in Ireland has grown by 60% more than anticipated. Dairy processing requires a significant hydraulic demand, with approximately 2.5 m3 of water required to process 1 m3 of milk. This research examined water usage and opportunities for reduction, recovery and reuse within the Irish dairy industry. Previous research into dairy waste streams is limited, with no real focus on chemical analysis of these waste streams. EU standards have not been widely compared to dairy waste streams and their seasonality year on year across multiple sites is not evident. Through collaboration with experts in nationwide sites critical areas of concern in terms of waste volumes, water cleanliness and technologies were discussed and led to a stable foundation for this research. Through thorough investigation of Irish Dairy waste streams this research was inconclusive in its ability to clearly group or classify waste streams within the industry. This in turn leads to ensuring any recovery technologies are competent of recovering a large variation of contaminated streams. Filtration technologies are currently in use in Dairy Industries within some production areas. However, it had yet to be investigated if this technology could assist with promising results in waste treatment. Ultrafiltration, Nanofiltration and Reverse Osmosis technologies were investigated with UF showing the least promise and RO the highest reduction of undesirables. This research then concluded that RO polishing post initial filtration poses conditions for optimum clean water recovery. Zeolites are a cheap, widely available and naturally occurring material that has been used in pharmaceutical and fine chemical industries for ca. 100 years. Extrapolating from the results obtained in this work, one would expect zeolites 4Å and 13X to clean 180m3 and 230m3 of dairy wastewater per tonne of material which translates to processing 72m3 and 92m3 of milk. Customer perception remains a significant misunderstood obstacle. Studying socioeconomical aspects of human behaviour, both within and external to an industrial setting, may aid in understanding people’s reluctance, and indeed, tendency to reuse traditional industrial waste streams.