The purification of water for the next century is paramount. As global demand for energy increases new ways of generating energy have been discovered and exploited. However, with the diversification of energy sources one thing remains constant, the water energy nexus. The water energy nexus is the intimate connection of water generation to energy generation and visa-versa. In other words, to have energy clean water is needed and to have clean water energy is needed. Because of this, new methods of water purification and monitoring have been investigated and developed.Herein the author describes new water purification methods using zwitterionic surfaces which have been used to purify various types of water including to date the most difficult waters such as ‘oilfield brines’. The author also describes techniques developed to monitor the chemical content of the oilfield brine which may be adapted for use at on-site wells as well as techniques which may be utilized to monitor for aquifer contamination by oilfield operations via nanoparticle sensors.