Fig. 5.

Effect of the addition of bulking agents, nutrients, and surfactants on the heavy oily sludge degradation. a Without addition of Tween 80, b Tween 80 [0.5%], and c Tween 80 [1%]. The degradation of TPH (%) is shown next to each treatment. Error bars represent the standard deviation of three replicates. B2 soil, organic fertilizer, sawdust, grass, cow manure, biosolids, and molasses, B5 soil, cow manure, rice husks, molasses, and inorganic nutrients, C1 soil, sawdust, and inorganic nutrients