Characterisation of a micro-pressure filtration and cleaning system under sandy and brackish water conditions.

To investigate the hydraulic effects and performance of the micro-pressure filtration and cleaning tank under conditions with sandy and brackish water, physical model tests were conducted with five groups of flow rates (6–14 m³ h−1), four groups of sediment contents (0.5–2.0 g l−1), five groups of mineralisation degrees (0–5.0 g l−1), and three groups of screen apertures (0.125, 0.150, and 0.180 mm). Dimensional analysis, multiple linear regression analysis, and the non-dominated sorting genetic algorithm II (NSGA-II) were used to analyse the test results. The results showed that the optimal operating conditions of the micro-pressure filtration and cleaning tank under the scope of this test were a screen aperture of 0.175 mm, a flow rate of 13 m3 h−1, a sediment content of 1.8 g l−1, and a mineralisation degree of 4.7 g l−1. The micro-pressure filtration and cleaning tank was intermittently discharged and rinsed, the discharge time was 30–40 s, and the flow rate of discharge and rinsing was 5.54 m3 h−1. Prediction models of the head loss and the filtration efficiency of the filter were established. The coefficients of determination (R2) were greater than 0.9, the average relative errors of the predicted and measured values were 2.98% and 2.17%, respectively, and the corresponding root mean square errors were 0.0549 m and 0.642. The research results can be used as a reference for in-depth investigations on the performance of the micro-pressure filtration equipment in front of pumps. • Head loss and filtration efficiency models of pre-pump filters were established. • Optimal working condition of the filter was obtained using NSGA-II. • Optimal discharge time and discharge flow rate were determined. [ABSTRACT FROM AUTHOR]