TY - JOUR
T1 - Characterization of sewage sludge and toxicity evaluation with microalgae
AU - Pun, K. C.
AU - Cheung, R. Y.H.
AU - Wong, M. H.
N1 - Funding Information:
assistance. Financial support from The City University of Hong Kong and Hong Kong Baptist University is gratefully acknowledged.
PY - 1995
Y1 - 1995
N2 - Heavy metal contents (Cd, Cr, Cu, Pb, Ni and Zn) of digested sludge, collected from sewage treatment works (Shatin (ST), Shek Wu Hui (SWH), Tai Po (TP) and Yuen Long (YL)) in 1992, 1993 and 1994, were analysed by atomic absorption spectrophotometry after sequential extraction by 1 m KNO3, 0.5 m KF, 0.1 m Na4P2O7, 0.1 m EDTA and 6 m HNO3. It was found that the major forms of Cu, Pb, Ni and Zn were in the sulphide phase, organically-bound phase, adsorbed phase and carbonate phase, respectively. A dinoflagellate (Dunaliella tertiolecta) and a diatom (Thalassiosira sp.) were used as bioindicators to test the toxicity of digested sludge samples collected in 1994. Each of the algae were inoculated to elutriates of digested sludge at different concentrations. The toxicities of the four types of sludge, according to 96 h-IC50s, were ranked as follows: TP > ST > SWH > YL for D. tertiolecta and ST > SWH > TP > YL for Thalassiosira sp. For D. tertiolecta, a significant correlation was found between algal inhibition and ammonium-N, both in sludge (p<0.05) and elutriates (p<0.01).
AB - Heavy metal contents (Cd, Cr, Cu, Pb, Ni and Zn) of digested sludge, collected from sewage treatment works (Shatin (ST), Shek Wu Hui (SWH), Tai Po (TP) and Yuen Long (YL)) in 1992, 1993 and 1994, were analysed by atomic absorption spectrophotometry after sequential extraction by 1 m KNO3, 0.5 m KF, 0.1 m Na4P2O7, 0.1 m EDTA and 6 m HNO3. It was found that the major forms of Cu, Pb, Ni and Zn were in the sulphide phase, organically-bound phase, adsorbed phase and carbonate phase, respectively. A dinoflagellate (Dunaliella tertiolecta) and a diatom (Thalassiosira sp.) were used as bioindicators to test the toxicity of digested sludge samples collected in 1994. Each of the algae were inoculated to elutriates of digested sludge at different concentrations. The toxicities of the four types of sludge, according to 96 h-IC50s, were ranked as follows: TP > ST > SWH > YL for D. tertiolecta and ST > SWH > TP > YL for Thalassiosira sp. For D. tertiolecta, a significant correlation was found between algal inhibition and ammonium-N, both in sludge (p<0.05) and elutriates (p<0.01).
UR - http://www.scopus.com/inward/record.url?scp=0029416447&partnerID=8YFLogxK
U2 - 10.1016/0025-326X(95)00123-5
DO - 10.1016/0025-326X(95)00123-5
M3 - Journal article
AN - SCOPUS:0029416447
SN - 0025-326X
VL - 31
SP - 394
EP - 401
JO - Marine Pollution Bulletin
JF - Marine Pollution Bulletin
IS - 4-12
ER -