Minimizing the use of chemicals to control scaling in SWRO : improved prediction of the scaling potential of calcium carbonate

 Content: Chapter 1 1.1 Background  1.2 Problem definition  1.3 The Overall Aim of the research  1.4 Research objectives  1.5 References  Chapter 2  2.1 Abstract  2.2 Background  Introduction Induction time Measurement tools  Effect of exchange CO2 on induction time  2.3 Materials  Inductively coupled plasma  Conductivity meter  pH meter  Reactors  Synthetic seawater concentrate preparation 2.4 Methods Measurement of calcium with ICP  Salinity and accuracy of direct measurement of calcium in solution Measurement of calcium carbonate retained on membrane filters  Effect of salinity, stability and accuracy of conductivity and pH measurment  Effect of mixing on the induction time  2.5 Results Effect of salinity on the ICP measurements and accuracy  Accuracy of measurement of calcium carbonate retained on membrane filters  The effect of salinity on the conductivity and the pH measurments  The effect of carbon dioxide exchange in an open system 2.6 Conclusions  2.7 List of Symbols  2.8 References   Chapter 3  3.1 Abstract  3.2 Background  3.3 Materials  Synthetic seawater concentrate preparation 3.4 Methods  The effect of particles in synthetic seawater on the induction time  The effect of particle addition  Mixing effect  3.5 Results and discussion  The effect of particles in synthetic seawater on the induction time  The effect of particle addition  The effect of mixing speed on the induction time  The nucleation mechanism  3.6 Conclusions  3.7 List of symbols  3.8 References   Chapter 4  4.1 Abstract  4.2 Background Introduction  Solubility of salts  Common methods used to determine the precipitation potential of CaCO3:  Stiff & Davis Stability Index (S&DSI)  Saturation Index (SI)  Saturation Ratio (Sa)  Mechanism of nucleation  Homogenous nucleation  Heterogeneous nucleation in a solution  Induction time  CaCO3 phases  The formation of hydrated CaCO3 forms  4.3 Materials  pH meter  Reactors  Synthetic seawater concentrate preparation  4.4 Methods  Induction time measurements  Solutions concentrations  Calculation of SI using PhreeqC  4.5 Results  The solubility product used by the S&DSI  Homogenous and heterogeneous nucleation  4.6 Conclusions  4.7 List of symbols  4.8 References   Chapter 5  5.1 Abstract  5.2 Introduction  5.3 Background  Saturation indices  Calculation of pH in SWRO concentrates  Effect of salinity on dissociation constants  Effect of salinity on the ion activity  5.4 Materials and Methods  Pilot plant  Concentrate pH in SWRO systems  5.5 Results and Discussion  pH calculations using equilibrium equations  pH calculations using manufacturers software  pH prediction using Phreeqc evaporation model  Field seawater concentrate measurements  5.6 Conclusions  5.6 List of Symbols 5.7 References   Chapter 6 6.1 Abstract  6.2 Background  Introduction  Calcium carbonate phases  The role of inorganic ions  Solubility of salts Common methods used to determine the precipitation potential of CaCO3:  Saturation indices (SI and Sa)  Mechanism of nucleation  Induction time  6.3 Materials pH meter Reactors  Synthetic seawater concentrate preparation  6.4 Methods Induction time measurements  Determination of co-precipitation  Determination of the final crystal phase of calcium carbonate 6.5 Results and discussion  Chapter 7  7.1 Conclusions 7.2 Recommendations for future work