Technical Abstract: Flax shive constitutes about 70% of the flax stem and has limited use. Because shive is a lignocellulosic by-product, it can potentially be pyroylzed and activated to produce an activated carbon. The objective of this study was to create an activated carbon from flax shive by chemical activation that shows significant binding of select divalent cations (cadmium, calcium, copper, magnesium, nickel, zinc). Shive carbons activated by exposure to phosphoric acid and breathing are showed breater binding of cadmium, copper, nickel or zinc than a sulfuric acid-activated flax shive carbon reported in the literature and a commercial, wood-based carbon. Uptake of calcium from a drinking water sample by the shive carbon was similar to commercial drinking water filters that contained cation exchange resins. Magnesium removal by the shive carbon was greater than a commercial drinking water filtration carbon but less than for filters containing cation exchange resins. The results indicate that chemically activated flax shive carbon shows considerable promise as a component in industrial and residential water filtration systems for removal of divalent cations.