A new commercial prototype of a bubble column evaporator (BCE) for high-quality water production in livestock (piggery) farms

The bubble column evaporator (BCE) offers a novel thermal process with enhanced evaporation efficiency, due to the enhanced heat and mass transfer efficiency from a continuous stream of hot dense bubbles that rise into a column of solution. This work evaluates the viability of the BCE to produce purified water from two different experimental solutions: synthetic piggery effluent and 0.5 m NaCl solution, when sparging with either hot air or combustion gas flow. When the BCE prototype was operated with combustion gas, an increased heat and mass transfer efficiency was observed due to the heat released by the condensation of hot water vapour in the com-bustion gas mixture, therefore reducing the energy cost when using combustion gas to evaporate the column solutions. For the first time, the quality of the condensed water from the BCE prototype was analysed and the report showed that high-quality condensed water could meet the most rigorous international drinking water quality standards, thus being safe to reuse in the piggery farm. In general, this paper provides a simple and affordable water treatment process that can be applied in the livestock (piggery) farm for efficient water reuse.