Effects of Sewage Sludge Compost on Growth and Heavy Metal Accumulation in Horticultural Plants

Abstract:

An investigation was made of the effects of land utilization of sewage sludge compost on growth and heavy metal accumulation in tall fescue (Festuca arundinacea Schreb) and marigold (Tagetes erecta) in the pot scale experiments.The results show that sewage sludge compost significantly increases the level of Zn,Cu,Pb in the soil.The plant biomass,height,absorption of total nitrogen and phosphorus increase gradually with sludge compost application ratios of 0~10% in Festuca arundinacea Schreb or 0~5% ratios in Tagetes erecta.The enrichment of heavy metals in both plants decrease in an order: Zn>Cu>Cr,Ni>Cd,Pb.And Zn,Cu,Cr,Ni enrich more significantly in Festuca arundinacea Schreb than Tagetes erecta.In a word,the highest elimination of heavy metals in mixed soils,especially for Zn and Cu,is obtained at 10% or 5% sludge compost ratio for Festuca arundinacea Schreb or Tagetes erecta,respectively.

Key words:sewage sludge compost; heavy metal; Festuca arundinacea schreb; Tagetes erecta; enrichment