| 摘要 |
We disclose a process for the removal of phosphorous and ammonia from an aqueous stream by contacting the aqueous stream with magnesium and base in a first zone having a first pH, to form an (n-1)th mixed stream and a first portion of struvite; separating the (n-1)th mixed stream from the first portion of struvite; removing at least some struvite from the first portion of struvite; contacting the (n-1)th mixed stream with base in an nth zone, wherein n is an integer incrementing from 2 to nmax, wherein nmax is an integer from 2 to about 5, and wherein the nth zone has an nth pH higher than the (n-1)th pH, to form an nth mixed stream and an nth portion of struvite, except no base is added and the nth pH need not be higher than the (n-1)th pH when n=nmax; separating the nth mixed stream from the nth portion of struvite; returning the nth portion of struvite to the (n-1)th zone; and, if n<nmax, incrementing n and repeating the second contacting, second separating, and returning steps, or, if n=nmax, releasing the nth mixed stream to a treated water tank. We also disclose a system which can be used for performing the method.
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