Term 252

Water Softening-Based Scale Management in Water Treatment Systems

Project Type: Self-Initiated

Project Description

Calcium carbonate (CaCO3) scaling is a common issue in water-treatment and industrial fluid-handling systems, where supersaturation leads to crystal formation and deposition on equipment surfaces. This project focuses on studying, predicting, and controlling CaCO3 scaling using a packed-bed reactor operated as a controlled side-stream unit. The objective is to understand how different operating conditions influence scaling behaviour and to evaluate the effectiveness of forcing scale to form inside a designated reactor instead of uncontrolled locations. A physical packed-bed prototype was designed and constructed to allow controlled testing of scaling under various operating conditions. The prototype enables measurement of several engineering parameters, including mass of deposited solids on the packing media, bulk precipitation rate, attachment ratio, and changes in water chemistry before and after the reactor. The effect of flow rate, contact time, and packing-media type is investigated to identify conditions that promote or limit CaCO3 deposition. Thermodynamic modeling is performed using Aspen software to calculate solubility and supersaturation levels based on inlet water properties. These results help define the operating window where scaling is expected to occur. In addition, MATLAB is used to develop an empirical model that correlates the experimental data with operating variables, providing a tool to predict scaling severity under different conditions. A safety assessment is included using standard hazard identification and evaluation methods to ensure safe operation of the experimental setup. The project also includes an economic comparison between the packed-bed approach and traditional industrial scaling-control methods such as chemical inhibitors, acid cleaning, and mechanical pigging. The comparison covers capital cost, operating cost, and expected payback period. This work provides experimental and modeling insights into controlled CaCO3 precipitation in packed-bed systems. Future steps include expanding the experimental matrix, testing additional materials, and refining the predictive model for use in different industrial applications.