reaction in the reactor 101 binds the contaminant into a flock material which is passed with the remaining fluid to a flock removal subsystem 102 a flock removal subsystem 102 can comprise a holding vessel 103 and a filter 104 after the flock is removed the remaining fluid cleaned of the contaminant exits the apparatus via an outlet 109 the invention can also comprise control of the ph of the reaction described below an open system method of decontaminating fluid according to the present invention comprises fluid processing through a reactor the fluid is passed between a reactor anode and a reactor cathode subject to electrical potential and for an amount of time effective to separate the contaminants from the fluid the reaction can increase the ph of the fluid the contaminants and fluid form into a flock material and small amounts of o2 and h2 the fluid and the flock can then be passed to a holding vessel the holding vessel can comprise a hollow container which adds residence time to the flock building process an amount of time suitable for the flock building process can elapse and then the fluid and the contaminants can be passed to a filter as the.