Membrane desalination system and method

摘要

[0042] A desalination system comprises a membrane separation device (12) and an adjustment unit (14). The membrane separation device (12) is configured to receive a feed stream (11) including one or more antiscalants and produce a permeate stream (15) and a concentrated stream (16). The adjustment unit (14) is configured to adjust at least a portion of the one or more antiscalants in the concentrated stream (16) from the membrane separation device (12)by decreasing pH of the concentrated stream or by increasing the temperature of the concentrated stream, thereby releasing ions of sparsely soluble salts from their complexes with the antiscalants. The precipitated is separated in a concentration device (13). The concentrated stream is returned to the feed side of the membrane separation device (12), the pH being increased in stream (17) by means of an activation device (18). A desalination method is also presented.