The application of magnetic fields for landfill leachate treatment

Abstract

This research is mainly focused on the capability of magnetic application of 0.55 Tesla magnetic field strength on reduction of suspended solid (SS), BOD5 and COD in landfill leachate through a circulation magnetic device which was conducted using the settling column test. The parameters monitored which effect the reduction of suspended solids and organic concentration were the magnetic exposure time of between 1 hour and 6 hours, operating flow rate of between 1 mL/s and 5 mL/s, and pH of between 2 and 13. Empirical mathematical models of sedimentation and column settling test were investigated to fulfill the behaviour of sedimentation under operating conditions due to the effect of magnetic exposure time, operating flow rate, and pH of the sample. Using the empirical mathematical models were analysed based on total suspended solids (SS), BOD5 and COD removal efficiency to variation of the operating flow rate, magnetic exposure time and pH. The model coefficients were derived from combined analysis of correlated sets of data, thus giving an indication for their possible general applicability. The pH had significant effects on the percentage of SS, BOD5 and COD removal, but pH increased the starting SS, BOD5 and COD removal rate. The study reveals that percentage of SS, BOD5 and COD removal efficiency decreased as the pH below 7 was increased, but it increased as the pH of between 7 and13 was increased the reduction of SS, BOD5 and COD in the sample. The experimental design at an exposure time to magnetic field of 6 hours, a flow rate of 2 mL/s with pH of 13 show that the removal efficiency of SS, BOD5 and COD at 72.57%, 63.93% and 56.97% respectively. Statistically tested by SPSS, there was a significant linear increase in average treatment efficiency to the magnetic exposure time and pH of sample at 95% confidence level. The experimental results were also generated empirical mathematical model relating percentage of SS, BOD5 and COD removal efficiency to flow rate, magnetic exposure time and sample of pH using MINITAB statistical software. The empirical mathematical models can be helpful in designing application of magnetic fields for landfill leachate treatment.