Effects of Capping with Recycled Aggregates and Natural Zeolite on Inhibition of Contaminants Release from Marine Sediment

Abstract

In this study, capping with recycled aggregate and natural zeolite in marine sediment was performed to investigate its inhibitory effect on pollutants released from sediment to seawater. An experiment was performed by capping with amendments for 60 days, and concentrations of organic matter (COD), nitrate, phosphate and metallic elements (Ni, Zn, Cu, Pb, Cd, As, and Cr) were measured. Two capping materials effectively suppressed pollutant release. Recycled aggregate showed better effectiveness for organic pollutant, nitrate and phosphate release. Meanwhile, natural zeolite was effective for metallic elements. As a result, recycled aggregate and natural zeolite can be considered as cost-effective/inexpensive capping material candidates. Also, the capping material can be selected according to the target pollutant.

Interactions of Cd2+, Co2+ and MoO42− Ions with Crushed Concrete Fines

“…The mechanical crushing, sieving and sorting of concrete-based demolition waste, for the recovery and reuse of the aggregates, produces a large volume of fine (<5 mm), low-density, cement-rich material for which further market development is required [7,10,11]. In this respect, a number of recent studies has been carried out that seek to exploit the porous, absorbent and alkaline nature of the cement-rich fine material in the treatment of contaminated water [1,3,5,6,10,[12][13][14][15][16][17][18][19][20][21][22][23] and marine sediment [24][25][26]. Crushed concrete fines (CCF) are reported to be effective in the removal of various heavy metal species (AsO 3 3− [12], CrO 4 2− [12], H n PO 4 (3−n)− [20][21][22][23], Cd 2+ [13][14][15], Cu 2+ [10,13,17,18], Ni 2+ [13], Pb 2+ [10,13,15,16,18], Zn 2+ [10,13,18]), radionuclides ( 60 Co 2+ …”