The present invention relates to the collection of alkalophilic/alkaline-tolerant microbes and use of said microbes in water glass wastewater treatment. The wastewater is treated directly with alkalophilic/alkaline-tolerant microbes cultured on granular activated carbon without any prior pH adjustment. Subsequently, water glass is separated from the biotreated water by lowering its pH. Alternatively, water glass is separated from biotreated water by distilling the water as water and water glass have different boiling points.