[Effect of Application of Sewage Sludge Composts on Greenhouse Gas Emissions in Soil].

Effect of application of sewage sludge compost on the emission of greenhouse gas from soil was investigated by analyzing the dynamic characteristics and emission factor of CO, CH and NO in soil after spiking two different composts (A:compost with biochar, B:compost without biochar) with varying fertilizing amount into soil. The results indicated that emissions of CO and CH mainly occurred in the plant growth period with low fertilizer amount of biomass charcoal compost reducing CO emissions, and high application content increasing CO emissions. CH emission fluxes showed negative values, indicating that soil could adsorb CH, and the adsorbing amount for control was significantly higher than those for other treatments (<0.

[Effect of Sewage Sludge Compost Products Application on Total Mercury and Methylmercury in Soil and Plants].

Two different sludge composting products (with and without biochar) were applied in field to study the variations of total mercury (THg) and methylmercury (MeHg) in soil and plants,as well as their migration in the soil-plant system and accumulation ability in plants during the sludge compost land use process.The results indicated that the concentrations THg and MeHg in soil increased after applying sewage sludge compost products,while the THg level was still lower than the secondary standard of national soil environmental quality.Biochar was speculated to probably promote the soil mercury methylation with lower MeHg/THg ratios in different soil treatments.

[Emissions Characteristics of Greenhouse Gas from Sewage Sludge Composting Process in Winter].

Sludge composting is an efficient way to realize the reclamation of waste sludge, while the Green House Gas (GHG) accompanying with it has raised great concern worldwide. However, we do lack the primary data in this area and a great uncertainty of the effect and GHG emission characteristics of sludge composting process in low-temperature environment also exists. This study is aiming to investigate the emission characteristics of GHG from composting in low-temperature environment by applying two different bulking agents to dewatered urban sludge.