Biological Reduction of Perchlorate from Spent Modified Reed Mediated by an Enriched Microbial Culture

Figure 4

Shrinking core model of perchlorate biodegradation from spent MR (drawn in SmartDraw). (a) Stationary phase (0–24 h): negligible removal, putatively due to EMC reacclimatization. (b) Transport of EMC from the bulk fluid to the MR surface. (c) EMC utilization of perchlorate at readily available monolayers (limited by reduction reaction rate). (d) Subsequent EMC utilization of perchlorate beneath the monolayer, which has to diffuse through pores and has reduced availability (smaller radius; trapped in pores). Removal slows, becoming dependent on the perchlorate diffusion rate. (e) Continued decline in the removal rate until all available perchlorate has been removed. (f) The removal rate is reduced considerably until it reaches a minimum. Trapped perchlorate is not recovered.

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