Woody peat was used as an additive to compost with pig manure in 1.2 m3 composting reactors under aerobic conditions for a 77?days period to estimate the effect on the compost maturity and gaseous emissions (NH3, N2O, and CH4). Pig manure was also composted with cornstalks (the traditional method) as a control treatment. The results showed that both cornstalks and woody peat composts reached the required maturity standard. Composting with woody peat as a bulking agent was found to reduced NH3 emissions by 36% than the cornstalks amended treatment. Although CH4 emission increased by adding woody peat, N2O emission was considerably reduced, resulting in a slight decrease in total greenhouse gas emissions. More importantly, woody peat could reduce the losses of total carbon and total nitrogen, improve the compost quality as fertilizer. 相似文献
Journal of Soils and Sediments - Crop residue return is an effective and low-cost agricultural approach for soil organic carbon (SOC) sequestration. Yet, it is largely unknown to what extent the... 相似文献
Sulfate-reducing bacteria (SRB) have received particular attention in the bioremediation of sediments contaminated with heavy metals. In this study, indigenous SRB were used to stabilize Cd in sediments spiked with different Cd concentrations (≤ 600 mg kg?1).
Materials and methods
The study investigated the Cd leaching efficiency from sediments after 166 days (d) of biotreatment and assessed the bacterial community and bacteria relationship in sediments during SRB biostabilization.
Results and discussion
The study found that the Cd leaching efficiency of sediments was reduced by 18.1–40.3% (29.4 ± 8.7%) after 166 days of biotreatment. During the biostabilization, the bacterial community in sediments significantly changed, particularly after 61 days of biotreatment. At the family level, the identified dominant bacteria (mean abundance > 3%) included Bacillaceae, norank Nitrospira, Anaerolineaceae, Nitrospinaceae, Streptococcaceae, and Hydrogenophilaceae. The study also speculated the complex relationships between these bacteria. The relative abundance of Desulfobacteraceae and Desulfobulbaceae in sediments was enhanced after biotreatment. Bacillaceae and Streptococcaceae may play a negative role in Cd biostabilization and inhibited SRB biological activity. However, Anaerolineaceae and Hydrogenophilaceae may have commensalism and mutualism relationships, respectively, with typical SRB. The presence of Nitrospinacea and norank Nitrospira may reduce the inhibitive effect of denitrifying bacteria on SRB, thereby exhibiting a positive effect on biologic sulfate reduction and Cd biostabilization.
Conclusions
Indigenous SRB treatment increased Cd stability in sediments and changed bacterial community. During SRB biostabilization, complex relationships between bacteria in sediments were speculated, including competition, syntrophism, and antagonism. These results provide insights for better regulating and controlling SRB biostabilization.