Turbidity Reduction of Groundwater by Using Nanomagnetic Adsorbent Composite (NMAC): Process Optimization by 3k Factorial Design and Analysis

Abstract

The widespread use of alternative water sources in Kelantan encourages the development of cost-effective methods for the purification of water. A simple and straightforward adsorption process using a nanomagnetic adsorption composite (NMAC) was introduced in this study as a new adsorbent for the treatment of turbid polluted groundwater. The use of iron oxide nano-coated adsorbents (NMACs) showed a high porosity relative to commercial activated carbons (CACs). Analysis of X-ray diffraction analysis for NMAC is confirmed by a crystal framework for Fe2O3, Fe3O4, and FeO are cubic components. A 3k maximum factor configuration of four factors, i.e., adsorbent dosage (0.02, 0.04, and 0.06 g), agitation time (15, 30, and 60 min), rotation speed (150, 200, and 250 rpm) and adsorbent scale (< 45 μm and >300μm) were used. The turbidity removal capability of both NMAC and CAC was compared. The adequacy of the developed empirical model for the elimination of turbidity and maximum turbidity efficiency was determined by regression model analysis. The obtained results revealed regression values of NMAC (R2; 0.9903, R2 adj.; 0.9875, R2 pred; 0.9808) and CAC (R2; 0.9909, R2 adj.; 0.9981, R2 pred.; 0.9817). The analysis of variance and surface response methodology revealed that turbidity removal efficiency of NMAC is affected by the four factors investigated. Among the samples, 0.04 g NMAC (< 45 μm) agitated at 150 rpm for 48 min showed 98.76% maximum adsorption efficiency. The findings showed that NMAC is a strong adsorbent for use in the treatment of raw water.