Dairy processing is a water intensive operation. For every liter of milk produced, up to 2 liters of wastewater are generated containing high levels of total suspended solids and organics. Wastewater treatment can have a significant impact on a processors total cost of operations from the cost of chemicals, trade waste charges, sludge disposal costs and labor requirements. With increasing competitive pressure and tightening environmental regulations, dairy processors are looking for innovative ways to improve their wastewater treatment performance and lower their overall operating costs.
An Australian dairy production facility making butter, lactose, powder and anhydrous milk (AMF) processes on average 1,000,000 liters of raw milk per day and generates up to 1,000 kiloliters per day of wastewater. The wastewater is processed through a Dissolved Air Flotation (DAF) system to reduce TSS and organics prior to being discharged to the local sewage treatment plant. In addition to the plant wastewater stream, the AMF process generates a product residue stream that had to be trucked off site and disposed of at significant cost to the plant.
The Dairy Processor was facing increased pressure from the local water authorities to reduce the quantity of water generated as well as the level of contaminants in the waste stream. In addition, a pending rate increase would result in a significant increase in the plant’s trade waste charges. Given these pressures, the plant began to actively investigate ways to improve their wastewater treatment operations including opportunities for water reuse/recycle.
Waterwerx was consulted on the use of its STREAMWISE Technology for DAF to help the plant:
Table 1 shows the improvement in DAF operation from existing to STREAMWISE control with 35% improvement in TSS and 43% FOG in the effluent translating to 42% lower BOD.
Table 2 shows the impact that maintaining lower TSS, BOD and FOG in the effluent has on the cost of operation, lowering trade waste charges by 26%. The continuous online chemical optimisation means that the improved DAF performance could be achieved while using 31% less treatment chemicals and requiring a significant 80% reduction in operator oversight.
In total, the STREAMWISE system will save this dairy processor over $268,000 per year.
STREAMWISE for DAF technology is helping this Dairy processing plant discharge cleaner wastewater to the local water treatment authority, while using less chemicals and lower operator oversight resulting in a significant reduction in their total cost of operation.
In addition, more efficient and consistent DAF operations will support future water reuse and recycling efforts.