Browsing by Author "Supian, Nur Sumaiyyah"

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    High gradient magnetic separation for wastewater treatment using steel wool to a curved pipe
    (Universiti Teknologi Malaysia, 2021) Supian, Nur Sumaiyyah
    Preliminary stage in wastewater treatment requires to remove various element such as grit, rags, oils, plastics, paper and other debris. The coagulation or flocculation process was the most essential process during preliminary stage which most various of colloidal and suspended particles were aggregated into larger form of flocs. The excessive amount of colloid accumulation and suspended particles generated a blockage during pre-treatment process. This could be influenced the performance for screening process. Thus, this study investigated the effect of magnetic gradient on sewage in controlling the formation of colloid and suspended particle through physical-chemical parameter that could further enhance preliminary treatment stage in the wastewater plant. The experimental design was conducted using response surface methodology (RSM) by central composite design (CCD). At initial of the study, preliminary study was carried out to select the best magnet orientation as well as pipe structure through factorial design. Then, the main effects such as flow rate, steel wool amount, exposure time and magnet strength were examined in the respect of turbidity, suspended solid and chemical oxygen demand (COD). Evaluation of interaction between factors were further studied. Statistical models describing relationship between the variables were developed. As a result, flow rate of 2.6 ml/s, steel wool proportion of 95 g, 11 hours of circulation time and at 200 mT of magnetic strength were indicated as optimal condition. An optimum result was achieved at 91.1% of turbidity, 93.6% of suspended solid and 86.4% in COD removal performances. Furthermore, the effect of magnetic gradient (MG) influenced the removal rate was further observed. Using the similar optimized factors condition, resulted the appropriate amount of steel wool influenced the removal rate the most. Both of MG1 and MG2 consists magnet strength of 200 mT. However, amount of non-corrosive stainless-steel wool for MG1 was 40g and MG2 consists of 120 g. MG2 conditions generated a higher value of removal rate compared to MG1. The result for suspended solid and COD removal of MG2 conditions compared to MG1 were indicated 88% and 80% removal rate with concentration of 20 mg/l and 80 mg/l, respectively. However, both of MG2 removal in suspended solid and COD were lower than optimum result (Suspended solid: 93.6%; COD: 86.4%). From this study, the sufficient magnetic gradient created by magnetized steel wool accelerated the physical-chemical processes compared to solely depend on magnet strength. Therefore, analysis proved that magnetic field capable to enhance the removal performance from sewage through improvement on curved pipe of the system. These optimal operating factors offered important reference values for later continuous flow experiment.