Method for optimizing chemical precipitation of raw- and wastewater

Purpose and goal

The overarching aim of this project was to optimize purification and running costs of chemical precipitation by developing a novel and patentable method that regulates the basicity of aluminium based coagulatants in situ. We approached this by developing a pilot scale reactor for raw water, followed by a full scale industrial reactor. This allowed us to study the relationship between dose of coagulants and basicity, and to further utilize these results to further explore and optimize the processes of precipitation.

Expected results and effects

Our results have clearly shown that changing basicity in situ can be used to modify the characteristics of an aluminum based coagulant. This effect can be utilized to effectively direct the relationship between dose of coagulant and basicity, which in turn can be utilized for optimization of treatment result and economy. This allows the operator to precisely adjust the need for a coagulant, instead of being forced to use a fixed, and often superflous amount, of chemicals. The rational for such product is obvious, since it decreases environmental toxicity and favors the economy.

Planned approach and implementation

The proposed experimental plan has followed the initially proposed strategy that was outlined in the approved grant. We successfully developed a pilot scale reactor, which allowed us to proceed to a fullsize reactor with capacity to handle sewage water. The tests of these reactors have been in operation since January. We have, in this time-frame, progressed from an early/pilot stage reactor to a full scale unit. Our initial analysis of the results are very incurraging and we are currently in the process of an in-depth and more detailed analyzing of our data.