The role of bulking agent in pile methane and carbon dioxide concentration during wastewater sludge windrow composting.

Wastewater sludge and wood chips were used as feedstock for the construction of two piles, Pile I ("PI") and Pile II ("PII"), at a ratio of 1:1 and 1:2 v/v, respectively. Each pile was originally 1.3-m high, 2.