Demonstration using reclaimed water as drinking water for dairy calves

DEMOWARE

Waste water source

The water comes from teh wastewater treatment plant of Caldes de Montbui.

Distribution System

The effluent resulting from the secondary treatment in the WWTP in Caldes de Montbui is transported by a tanker truck to a 27 m³ closed tank in the facilities of Torre Marimon. The UF module is attached to this tank and operates in crossflow mode during the necessary daily period to have around 300L/d of permeate. All piping is made of plastics(PVC) black tubing to avoid algae growth. Permeate water is diverted to a black storage tank of 1000L. UF and UV modules are separated by half km distance. Every approximately three days, the filled tank of 1000 L is exchanged with the one that feeds the UV module.

Farming system

The case study focused on the use of reclaimed water for drinking water for dairy calves during pre-weaning period(aged from day 5 to 48). Furthermore, the reclaimed water was also used for the cleaning of livestock facilities.

Costs

For a 375 m³ a day secondary treatment system (MF + UV) a cost of 0.42 euro/m³ is calculated. For a bigger system with a capacity of 3750 m³/day, the cost comes at 0.18 euro/m³.

The detail of the capital and operational costs of a tertiary treatment water plant based on membrane filtration and UV disinfection are figured below.

Scientific results

Some conclusions from the experiments are:

• The water treatments with the lowest impact on the intestinal cells are the tertiary treatments that consisted on an UF followed by an UV disinfection and the UF treated WW without disinfection. The causes of the different results are difficult to know with the experimental design of this study, but it is clear that the UF technology contributes positively to the overall cell performance.
• The reclaimed water obtained by the treatment scheme installed in Torre Marimon, based on a UF and a UV disinfection achieved a water quality that fulfil most of the water quality objectives set for livestock drinking except for some salts, such as Na+ and Cl- , that they were found at concentrations around the threshold limits
• The use of reclaimed wastewater for livestock drinking and farming cleaning does not pose an acute risk for animal health.
• The in vivo experiments showed that reclaimed water, which has higher content of dissolved salts than tap drinking water, was less preferred by animals and probably this is the reason that these same animals had slightly lower feed consumptions and weight gains

Martinez, X., Bosch, C., Terre, M., Biel, C., Vergine, P., & Pollice, A. (2014). Innovative schemes for water reuse in the agricultural sector - DEMOWARE D1.5 (Vol. 1).: http://demoware.eu/en/results/deliverables/deliverable-d1-5-recommendations-on-water-reuse-in-the-agricultural-sector.pdf/view