Time-Dependent Changes in Soluble Heavy Metals from Incinerated Sewage Sludges Applied Soil

DOI JASI Web Site 1 Citations

Bibliographic Information

Other Title
  • 下水汚泥焼却灰施用土壌における可溶性重金属最の経時変化
  • 下水汚泥焼却灰施用土壌における可溶性重金属量の経時変化
  • ゲスイ オデイ ショウキャクバイ セヨウ ドジョウ ニ オケル カヨウセイ ジ

Search this article

Abstract

Effect of application of sewage sludges and their ashes on soluble heavy metals in a soil was studied. Sludge samples consisted of two limed sludge cakes, two no-limed sludge cakes and four ashes prepared from theirslu dge cakes by 800℃ incineration treatment. These materials were applied to soil (volcanic ash soil) at a rate of 2.0 g P_2O_5 per 1.5 kg dry soil in pots. These were incubated in the dark at 30℃ for 1, 13, 26, 52 and 156 weeks. At the end of each incubation period, the soluble Fe, Mn, Zn, Cu, Pb and Cr were measured in the extracts by diethylenetriamine pentaacetic acid (DTPA) and 0.1 N HCl. The following results were obtained. 1) Amounts of soluble heavy metal were less by the application of ash than sludge cake (both limed materials and no-limed materials). Although these decreased ratios were different according to the species of metal and the method of extraction, the amount of soluble Zn and Cu were only a third or even less, regardless of the method of extraction. 2) Amounts of soluble heavy metal were decreased by application of sludge cakes gradually ; but these showed little or no change and were small after 156 weeks by application of ashes. 3) When extraction of HCl concentration increased, the amounts of extracted heavy metal were less by the application of ashes than application of sludge cakes. And amounts of extracted Zn and Cu were increased in proportion to eluate pH. These slopes of proportional straight-line were smaller by the application of ashes than application of sludge cakes even after 156 weeks. 4) Therefore, it is considered that insoluble forms of heavy metal by the incineration treatment were stable at least three years on upland conditions.

Journal

Citations (1)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top