Effect of magnesium addition to volatile fatty acids and particulate chemical oxygen demand in hydrolysis phase of anaerobic waste treatment

Abstract

Anaerobic Digestion (AD) is an alternative technology used for treating food waste. Sodium content in food waste with a concentration of > 3.100 mg/L has the potential to cause inhibition. Sodium inhibition can be controlled with magnesium. In steady state conditions, the control phase shows the average Chemical Oxygen Demand (COD) removal 94.2 ± 3.34%, Soluble Chemical Oxygen Demand (SCOD) 98 ± 1%, Particulate Chemical Oxygen Demand (PCOD) 94 ± 3.6%, and formation of Volatile Fatty Acids (VFA) 1,800 ± 200 mg/L and hydrolysis rate 6.92 ± 0.32 mg.PCOD/L/d. The addition of MgSO4 in the test phase showed a significant difference in the formation of VFA to 1,066 ± 57.7 mg/L. While the average allowance for COD, SCOD, and PCOD did not show a significant difference with a value of 84.7 ± 6.8% respectively; 96 ± 1%; 83.3 ± 7.3%. The hydrolysis rate in the test phase also did not show a significant difference to 6.24 ± 0.57 mg.PCOD/L/d.