Increase in complexation ability of humic acids with the addition of ligneous bulking agents during sewage sludge composting.
Wood sawdust and maize straw were selected to co-compost sewage sludge to investigate the effects of organic bulking agents on the formation and molecular transformation of humic substances. The results showed that composting process increased humic acids (HA) while decreased fulvic acids (FA), and the wood sawdust and maize straw promoted the formation of HA by 25.6% and 16.1%, respectively. Results from fluorescence titration demonstrated that organic bulking agents also increased the binding ability of HA with the heavy metal ions, Cu(II) and Cd(II), but had little influence on that of FA. These findings indicate that organic materials especially wood sawdust may be used as bulking agents to reduce the mobility and bioavailability of toxic metals in solid waste composts.
Xiong
Xiong
X
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, 19 Xinwai Street, Beijing 100875, China.
Yan-Xia
Li
L
Ming
Yang
Y
Feng-Song
Zhang
Z
Wei
Li
L
D001578:Benzopyrans / Q000032:analysis; D002244:Carbon / Q000032:analysis; D005453:Fluorescence; D006812:Humic Substances / Q000032:analysis*; D007477:Ions; D008031:Lignin / Q000737:chemistry*; D008670:Metals / Q000737:chemistry; D012044:Regression Analysis; D012722:Sewage / Q000737:chemistry*; D012987:Soil
D001578:Benzopyrans; D006812:Humic Substances; D007477:Ions; D008670:Metals; D012722:Sewage; D012987:Soil; D002244:Carbon; D008031:Lignin; C005023:fulvic acid