The problem –
A WWTP did not achieve the water quality required as one of its primary settlers got out of action due to mechanical breakdown.
The increased organic load on the biological reactors did not allow the production of good quality effluent.
It is known, that the use of coagulants (mineral) reduces significantly the organic load and allows more rapid settling.
The solution
Injection of Sodium Aluminate at the entrance of the sole primary settler.
Results
The wastewater station operated for more than one year with one settler
The effluent of the WWTP reached the required quality.