Facility will use reverse osmosis and evaporation/crystallization
U.S. Water Services, Plymouth, M.N., will offer a chance for an ethanol plant named Big River Resources to utilize the advanced technologies of the patented high-efficiency reverse osmosis process and the evaporation and crystallization process together. Combining the two processes will achieve zero liquid discharge in the water treatment facility.
The 100 million gal-per-year ethanol plant in Galva, Ill. is expected to start up in early 2009.
Big River Resources (BRR) had to consider several treatment options due to the high mineral content in the local well water. In addition, discharge was an issue and BRR was looking at running pipelines to the closest river 30 miles away.
There are four major processes the water will go through. The first process is dual softening, consisting of a strong acid cation sodium cycle and a weak acid cation. The second process is a decarbonator, which greatly reduces carbon dioxide. The HERO will raise the pH to 10 in the third process, whereby water recoveries of 95 to 97% can be achieved, thus greatly reducing discharge volumes. The last process is evaporation and crystallization, where zero liquid discharge results can be achieved by evaporating down the waste stream volume by 80 to 90%. The remainder is then crystallized to a land fillable solid that is non-hazardous to the environment.
U.S. Water Services’ presented this turnkey proposal to BRR and signed the agreement with them October 2007. The primary contractor on the water treatment building will be U.S. Water Services. Mobilization is slated to begin in February 2008, with completion occurring by December 2008.