Influence of volatile fatty acids in anaerobic bioleaching of potentially toxic metals

Molaey R., YEŞİL H., ÇALLI B., TUĞTAŞ KARNABAT A. E.

Journal of Environmental Management, cilt.285, 2021 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 285
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1016/j.jenvman.2021.112118
  • Dergi Adı: Journal of Environmental Management
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, International Bibliography of Social Sciences, PASCAL, Aerospace Database, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, CAB Abstracts, Communication Abstracts, EMBASE, Environment Index, Geobase, Greenfile, Index Islamicus, MEDLINE, Metadex, Pollution Abstracts, Public Affairs Index, Veterinary Science Database, Civil Engineering Abstracts
  • Anahtar Kelimeler: Anaerobic digestion, Bioleaching, Digestate, Potentially toxic metal, Sewage sludge, Volatile fatty acid, WASTE ACTIVATED-SLUDGE, EXTRACELLULAR POLYMERIC SUBSTANCES, HEAVY-METALS, SEWAGE-SLUDGE, CO-DIGESTION, SEQUENTIAL EXTRACTION, BIOGAS PRODUCTION, SPECIATION, PRETREATMENT, SOILS
  • Marmara Üniversitesi Adresli: Evet

Özet

© 2021 Elsevier LtdPotentially toxic metals are common contaminants associated with sewage sludge, and limited information is available on migration and transformation behavior of potentially toxic metals during anaerobic digestion (AD) process. The aim of this study was to reveal the influence of volatile fatty acids (VFAs) on the solubilization of metals through VFAs-metal complexation. Addition of readily biodegradable extra carbon source at organic loading rate (OLR) of 17.65 gVS/L.d resulted in accumulation of 67,255 mg chemical oxygen demand (COD)/L as VFAs. Low pH values due to VFAs accumulation enhanced the solubilization of Ni and more than 22% of its total concentration became soluble. Subsequent to consumption of VFAs and increase of pH to neutral levels (~7.5), solubility of Ni decreased below 10% of its total concentration. Contrarily, the solubility of Cr reached to 25% of its total concentration at neutral pH values. Presumably the complexation of Cr with dissolved organic matter (DOM) have increased its concentration in the liquid fraction at neutral pH values. Fractionation analysis of metals revealed that AD process altered Cu and Zn speciation between organically-bound and residual fractions, and hence solubility of Zn and Cu remained consistently low over the entire period of the AD process.