Developed a zero-dimensional nanofiltration unit model for the WaterTAP repository, enabling steady-state simulation of single-phase liquid processes with configurable solute rejection and solvent recovery fractions. The model incorporated options for electroneutrality constraints in the permeate, as well as adjustable pressure drop and temperature equality, supporting more realistic and flexible process simulations. Leveraging expertise in chemical engineering, process simulation, and unit modeling, the implementation utilized Python and Pyomo to ensure modularity and extensibility. Comprehensive documentation and usage scaffolding were provided to facilitate validation and adoption, supporting broader design-space exploration and early-stage optimization for nanofiltration process engineers.