A method of treating a metal-contaminated sediment includes capping the sediment
with a capping product containing sulfur and at least one component selected from
the group consisting of clays, clay-sized materials, bulking agents, sand, sand-sized
materials, aggregate, and binding agents. A capping product includes a plurality
of manufactured composite particles, each composite particle comprising a relatively
dense core and a sealant layer at least partially encapsulating the core, the sealant
layer including sulfur and at least one of the above components.