Publication Date:
2018-02-23
Description:
Applying sewage sludge to mudflat salt-soils can rapidly improve soil physicochemical properties while enhance pollution potential. Nevertheless, the heavy metal distribution in leachate and mudflat salt-soils with sludge amendment remains unclear. The present work was aimed primarily at investigating the fates of Cd, Cu, Pb, and Zn in mudflat salt-soils amended by sludge. A leaching column experiment in a greenhouse was conducted to analyze the leaching losses of the metals in the sludge-amended soils, and to evaluate the uptake of these metals by maize ( Zea mays L.) seedling, using a mudflat salt-soil amended with 0, 30, 75, 150, and 300 g sludge per kg soil. The results indicated that metal concentrations were significantly correlated negatively with pH and positively with dissolved organic carbon concentration in leachate of sludge-amended soils. The sewage sludge application enhanced metal uptake without inhibiting the growth of maize. The sludge treatments enhanced metal concentrations in top layer (0-20 cm) of soil in the leaching column, but did not change metal concentrations in soil layer of 20-40 cm ( p 〉0.05). Immobile fraction of Pb and mobile fraction of Cd, Cu, Zn increased with increasing rates of sludge addition. Long-term field studies are required for further evaluation of the impacts of recycling sludge on heavy metal behaviors including leaching, accumulation and dynamic change of metal fractions in mudflat salt-soils.
Print ISSN:
1085-3278
Electronic ISSN:
1099-145X
Topics:
Geography
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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