is insignificant and the bleeding replacement of the spent regenerant stream is minimal from an operational viewpoint the entire process can be broken down into the following three major steps or cycles for a typical secondary wastewater the duration of the first step removal is estimated to be 24 72 hours while the second and third step together will require approximately 3 6 hours no significant biological growth was observed within the ple column while treating the secondary wastewater from the bethlehem wastewater treatment plant the presence of cu ii in the polymer phase and use of 6 nacl during intermittent regenerations is believed to have inhibited any major bacterial growth even in the presence of dissolved organic matter a preliminary cost estimation for this process was carried out for removal of phosphate from the secondary wastewater of the bethlehem sewage treatment plant for capacities ranging from 1 1 to 12 3 mgd the estimated cost to reduce phosphate from 4 mg l to less than 0 5 mg l as p ranged from 25 to 35 per 1000 gallons of wastewater zhao 1997 it is universally recognized that a fixed bed sorption process is operationally simple requires virtually no start up time and is forgiving toward fluctuations in feed compositions and ambient temperature that is why fixed bed sorption processes were tried for phosphate removals at pilot scale levels in several places around the world eliassen 1968 kang 1990 nesbitt j b 1969 phosphorus removal the state of the.