No, pH extremes can be very disruptive to bacteria and can upset the operation of the wastewater treatment plant.  The RO cleaning solution should always be neutralized prior to sending to a wastewater treatment plant.  The solution is usually considered “neutral” in most cases if it is within a pH 5 – 9 range, however, always follow local regulations and comply with your discharge permits.

See also:

Default ThumbnailCan we send the CIP solution to our deep injection well after cleaning our Reverse Osmosis membranes? Default ThumbnailWhat is the procedure for cleaning RO membranes? What CIP chemicals should be used? Default ThumbnailWe recently installed new RO membranes in our system and observed that the permeate water tested positive for coliform bacteria. Is it possible in your experience that RO membranes could be damaged during installation and cause contamination of the water distribution system by bacteria and pathogens? Default ThumbnailOur RO plant doesn’t have a neutralization tank for our spent CIP solution. Can we just neutralize while circulating through the membrane system?