My first instinct is chemical ...
Published by Stanton Smith, VP Global Marketing at Nanostone Water
My first instinct is chemical precipitation. I agree with other answers that the final quality and maybe use of the treated water should be defined. Also need TDS, alkalinity, pH, TSS of feed to answer the question well. With no feed quality, the most flexible choice is chemical precipitation using MgO and/or aluminate for silica, and depending on pH, add caustic or lime or acid to get pH to about 10. Then clarify and/or filter as finely as needed, adjust pH as needed. Good luck.