Watertech

An integrated systems approach to analyse and sustainably design dairy wastewater treatment plants (WWTPs) for minimising energy consumption, capital and operational costs

Milk collection within the EU-28 increased by 1.8% from 2014 – 2015.  Skimmed milk powder (SMP), butter, cream and cheese production show similar trends, increasing by 8.1%, 3.3%, 1.5 and 1.4% respectively. According to the Food Wise 2025 strategy report, the global demand for whey is also growing at 11% a year. The changes in dairy processing to produce more whey, SMP, butter, and cheese products have a significant impact on the final effluent that is required to be treated by the wastewater treatment plant (WWTP).

The objective of the study is to identify the sources of wastewater throughout the processing stages as a means to characterise the wastewater to be treated but also to include the CIP (cleaning in place) chemicals and frequencies that are used and to highlight their effect on the WWTP.  Another issue not addressed fully in the current literature but will be highlighted through the research is the sensitivity of wastewater biology and reaction rates to changes in temperature.

Modern plants need to consider heat losses and heat gains to optimize performance during all climatic conditions. Once the wastewater is characterised, the next step will be to identify the existing and novel treatment systems that are available for pretreatment and secondary treatment and to analyse these systems in order to identify the best fit equipment by which to obtain maximum removal efficiency at lowest energy demand for specific wastewater parameters. To date, the study has examined results and information from available literature and highlighted the gaps in the literature in terms of CIP and temperature sensitivity.

The results of this research can aid in the development of guidelines for the design of sustainable wastewater treatment plants for the dairy processing industry.

Project Team

The Project Manager is Dr. Tom Curran, tom.curran@ucd.ie, UCD School of Biosystems and Food Engineering, UCD Agriculture and Food Science, University College Dublin, Belfield, Dublin 4.

The Principal Researcher is Sarah Stanley, UCD School of Biosystems and Food Engineering, UCD Agriculture and Food Science, University College Dublin, Belfield, Dublin 4.

The Employment partner is Seamus Crickley, WEW Engineering Ltd., 39B Hebron Business Park, Hebron Road, Kilkenny.

Acknowledgement

This project is funded by the Irish Research CouncilDepartment of Agriculture, Food and the Marine; and WEW Engineering Ltd. as part of the Employment Based Postgraduate Research Programme.