Plants grown on sewage sludge in South China and its relevance to sludge stabilization and metal removal

Abstract： The production of sewage sludge in China has been increasing sharply in order to treat 40% of the municipal sewage in 2005 as planned by central government. The main sludge disposal method is landfill owing to heavy metal contamination, but it presents an attractive potential for agricultural land application. Experiments were carried out to study the simultaneous metal removal and sludge stabilization by plants. The sludge samples were collected from Datansha Wastewater Treatment Plant of Guangzhou, it contained excessive Cu and Zn compared with the Chinese National Standard for Agricultural Use of Sewage Sludge. Plants growing on sludge beds were investigated to follow their growth and metal uptake. 30 sludge plants were identified during 1 year's observation. A Zn high-accumulating and high growth rate plant(Alocasia macrorrhiza) was selected and grown on sludge beds in plots. The water, organic matter, heavy metals and nutrients contents, the E. coli number and the cress seed germination index were monitored for the sludge samples collected monthly. The plant growth parameters and its heavy metals contents were also determined. The sewage sludge treated by plants could be stabilized at about 5 months, the E. coli number was significantly decreased and the cress seed germination index attained 100%. Crop on sludge could ameliorate the sludge drying. The experiments are continuing to find out the appropriate plant combination for simultaneous sludge stabilization and metal removal for an acceptable period. Comparisons between the proposed processes and other methods for treating produced sludge such as composting, chemical and bacterial leaching were discussed. 作 者： SAMAKE Moussa    Wu Qi-tang    Mo Ce-hui    MOREL Jean-Louis   作者單位： SAMAKE Moussa,Wu Qi-tang,Mo Ce-hui(College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China)

MOREL Jean-Louis(Lab. Sol et Environnement, ENSAIA/INRA, 54505 Vandoeuvre, France) 

期 刊： 環(huán)境科學學報(英文版)  ISTICSCI   Journal： JOURNAL OF ENVIRONMENTAL SCIENCES  年，卷(期)： 2003, 15(5)  分類號： X173 X53  Keywords： sewage sludge    hyper-accumulator    heavy metal removal    stabilization