Effect of humic and fulvic acid transformation on cadmium availability to wheat cultivars in sewage sludge amended soil

Imran Rashid*, Ghulam Murtaza, Zahir Ahmad Zahir, Muhammad Farooq

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)


The high nutrients and organic matter (OM) content of sewage sludge make it an excellent fertilizer to enhance soil fertility and crop production. However, the presence of adsorbed and precipitated forms of heavy metals, especially cadmium (Cd), can be a major problem for such a utilization of sludge. This pot study aims at producing safe food with minimal Cd concentrations from sewage sludge amended soils. Two wheat cultivars (NARC-11 and Shafaq-06) were sown in soil amended with sewage sludge with rates 0, 15 and 30 g kg−1 soil. Application of sewage sludge resulted in enhancement of wheat grain yield while Cd concentrations in wheat grains of both cultivars remained within permissible limits (24.1 to 58.6 μg kg−1 dry weight). Fourier transform infrared (FTIR) spectroscopic analysis revealed more spectral changes in fulvic acids than in humic acids, which showed a higher humification degree, making them chemically and biologically more stable for Cd retention. Sequential extraction data of Cd after NARC-11 harvest exhibited a significant decrease in mobile fractions (exchangeable and reducible fractions were reduced by 3.6 and 5.2%, respectively) and increase in immobile fraction (the oxidizable and residual fractions increased by 7 and 1.8%, respectively). It is concluded that sewage sludge application could be useful for the improvement of wheat production due to formation of stable humate complexes and decrease in Cd availability.

Original languageEnglish
Pages (from-to)16071-16079
Number of pages9
JournalEnvironmental Science and Pollution Research
Issue number16
Publication statusPublished - Jun 1 2018


  • Cadmium
  • Fulvic acid
  • Humic acid
  • Metal fractionation
  • Organic matter transformation
  • Spectroscopy

ASJC Scopus subject areas

  • Environmental Chemistry
  • Pollution
  • Health, Toxicology and Mutagenesis


Dive into the research topics of 'Effect of humic and fulvic acid transformation on cadmium availability to wheat cultivars in sewage sludge amended soil'. Together they form a unique fingerprint.

Cite this