A zwitterionic monomer and corresponding cyclopolymerized polyzwitterion () (PZ) (i.e. poly(Z-alt-SO.sub.2). Phosophonate ester hydroloysis in PZ gave a pH-responsive polyzwitterionic acid () (PZA). The PZA under pH-induced transformation was converted into polyzwitterion/anion () (PZAN) and polyzwitterion/dianion (=) (PZDAN).

A zwitterionic monomer and corresponding cyclopolymerized polyzwitterion () (PZ) (i.e. poly(Z-alt-SO.sub.2). Phosophonate ester hydroloysis in PZ gave a pH-responsive polyzwitterionic acid () (PZA). The PZA under pH-induced transformation was converted into polyzwitterion/anion () (PZAN) and polyzwitterion/dianion (=) (PZDAN).

A zwitterionic monomer and corresponding cyclopolymerized polyzwitterion () (PZ) (i.e. poly(Z-alt-SO.sub.2). Phosophonate ester hydroloysis in PZ gave a pH-responsive polyzwitterionic acid () (PZA). The PZA under pH-induced transformation was converted into polyzwitterion/anion () (PZAN) and polyzwitterion/dianion (=) (PZDAN).

A cleaning-in-place method for cleaning a membrane filter module, the membrane filter module including a membrane having a feed side and a permeate side and being configured to filter a fluid passing through the membrane from the feed side to the permeate side; wherein the method comprises performing a sequence of process cycles, the sequence comprising at least one monitored process cycle, the monitored process cycle comprising: providing a flow of a liquid through the membrane and/or across the feed side of the membrane; monitoring at least one hydraulic parameter associated with the provided flow of the liquid; and terminating the flow of the liquid, when the at least one monitored hydraulic parameter meets a predetermined cycle completion criterion.

Methods of operating an electrochemical separation device is disclosed. The methods include operating the electrochemical separation device in an active mode until the resistance reaches a predetermined threshold, regenerating the electrochemical separation device in a passive mode until the resistance reaches a predetermined threshold, and resuming operation of the electrochemical separation device in the active mode. The methods also include operating the electrochemical separation device in an active mode for a predetermined period of time, regenerating the electrochemical separation device in a passive mode for a predetermined period of time, and resuming operation of the electrochemical separation device in the active mode. Water treatment systems include the electrochemical separation device and a control module are also disclosed. Methods of facilitating operation of the electrochemical separation device by providing a control sequence are also disclosed.