Characterization of temperature and oxygen profiles in windrow processing systems

A study was undertaken to investigate the temperature and oxygen profiles i n a green organic windrow processing system developed by Environmental & Re source Technology Holdings Pty Ltd. The aim of the study was to characteriz e the effectiveness of a passive ventilation system in windrowed plant resi dues for the control of temperature and oxygen concentrations. Measurements were taken of the green organic material within 30 different stockpiles pr ior to processing and within 30 commercial windrows throughout processing. The highest and lowest temperatures recorded in windrowed processing materi al were 72.8 degrees C and 17.6 degrees C respectively. Predominantly therm ophilic conditions were maintained in the windrows throughout processing an d virtually all material was subjected to the commonly recognized 55 degree s C for three days which ensures the destruction of potential pathogens in organic material. The lowest oxygen concentration recorded in stockpiled in gredients and windrow processing material was 14.4 percent and 15.9 percent atmospheric respectively. Gaseous products of anaerobic origin were infreq uently detected with the range of the equipment employed, demonstrating tha t the windrow process remains aerobic on a macro-scale at all times and doe s not produce any offensive odorous products.