Permeable Reactive Barriers (Proceedings of the International Symposium held at Belfast, Northern Ireland, March 2004). IAHS Publ. 298, 2005, 154-160.

Abstract Permeable reactive barriers (PRBs) have demonstrated a promising approach for groundwater remediation. However, one concern is the deterioration of barrier material performance due to mineral precipitation and pore clogging. This study sought to quantify the effect of pore clogging on the alteration of the physical architecture of clinoptilolite and calcified seaweed using image analysis. Results after treatment with contaminated water for 1–10 months identified a decrease in porosity from approx. 22% to approx. 15% for calcified seaweed and from approx. 22% to approx. 18% for clinoptilolite. The mean pore size of both materials was also notably decreased after the treatment. An increase in irregular shaped pores was also observed in both materials after the treatment, mostly noticeably in the bottom of columns where the contaminated water first interacted with the barrier materials. The distribution of pores within an image derived from the distance transform indicated morphological differences in material between the bottom and the top of calcified seaweed columns, which is likely to impact on their performance as barrier materials.

Key words calcified seaweed; clinoptilolite; image analysis; permeable reactive barriers; pore clogging