TY - JOUR
T1 - Effects of lime amendment on availability of heavy metals and maturation in sewage sludge composting
AU - Fang, M.
AU - Wong, J. W.C.
N1 - Funding Information:
The work described in this paper was fully supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. HKBU 140/95M). The authors would like to thank Mr. K.K. Ma for his excellent technical assistance throughout this project.
PY - 1999/7
Y1 - 1999/7
N2 - A batch composting study was performed to evaluate the feasibility of co-composting sewage sludge with lime, aiming at reducing the availability of heavy metals in the sludge compost. Sewage sludge with sawdust as bulking agent was amended with lime at 0, 0.63, 1.0, and 1.63% w/w, and composted for 100 days in laboratory batch reactors. The changes in temperature, pH, electrical conductivity (EC), and extractable heavy metal contents were measured while compost maturity was determined by C/N(organic) and cress seed germination during the composting period. Liming raised pH of compost effectively at the initial stage of composting and caused a decrease in EC through precipitation of soluble ions. Lime amendment also significantly reduced water-soluble and Diethylene triamine pentracetic acid (DTPA)-extractable metal contents. The maximum reductions were 60 and 40% for Cu, 80 and 40% for Mn, 55 and 10% for Zn, and 20 and 25% for Ni at the end of the composting period for the lime-amended sludge as compared to the control. In spite of the inhibitory effect of lime amendment on the decomposition activity of sewage sludge, all treatments reached maturation after 63 days of composting as indicated by the results of C/N(organic) ratio and cress seed germination test results. A lime amendment of ≤1.0% is recommended to co-compost with sewage sludge. Copyright (C) 1999 Elsevier Science Ltd.
AB - A batch composting study was performed to evaluate the feasibility of co-composting sewage sludge with lime, aiming at reducing the availability of heavy metals in the sludge compost. Sewage sludge with sawdust as bulking agent was amended with lime at 0, 0.63, 1.0, and 1.63% w/w, and composted for 100 days in laboratory batch reactors. The changes in temperature, pH, electrical conductivity (EC), and extractable heavy metal contents were measured while compost maturity was determined by C/N(organic) and cress seed germination during the composting period. Liming raised pH of compost effectively at the initial stage of composting and caused a decrease in EC through precipitation of soluble ions. Lime amendment also significantly reduced water-soluble and Diethylene triamine pentracetic acid (DTPA)-extractable metal contents. The maximum reductions were 60 and 40% for Cu, 80 and 40% for Mn, 55 and 10% for Zn, and 20 and 25% for Ni at the end of the composting period for the lime-amended sludge as compared to the control. In spite of the inhibitory effect of lime amendment on the decomposition activity of sewage sludge, all treatments reached maturation after 63 days of composting as indicated by the results of C/N(organic) ratio and cress seed germination test results. A lime amendment of ≤1.0% is recommended to co-compost with sewage sludge. Copyright (C) 1999 Elsevier Science Ltd.
KW - Composting
KW - Heavy metal
KW - Lime
KW - Maturity
KW - Sewage sludge
UR - http://www.scopus.com/inward/record.url?scp=0033061024&partnerID=8YFLogxK
U2 - 10.1016/S0269-7491(99)00056-1
DO - 10.1016/S0269-7491(99)00056-1
M3 - Journal article
AN - SCOPUS:0033061024
SN - 0269-7491
VL - 106
SP - 83
EP - 89
JO - Environmental Pollution
JF - Environmental Pollution
IS - 1
ER -