Comparison of dried sludge and sludge ash for phosphorus recovery with acidic and alkaline leaching

SEMERCİ N., Ahadi S., Cosgun S.

WATER AND ENVIRONMENT JOURNAL, cilt.35, sa.1, ss.359-370, 2021 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 35 Sayı: 1
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1111/wej.12633
  • Dergi Adı: WATER AND ENVIRONMENT JOURNAL
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.359-370
  • Anahtar Kelimeler: chemical leaching, dried sludge, heavy metals, phosphorus recovery, phosphorus release, sludge ash, RELEASE, EXTRACTION, PH, FERTILIZER, STRUVITE, REMOVAL, FLOWS
  • Marmara Üniversitesi Adresli: Evet

Özet

Nowadays, the recovery of phosphorus has been in the spotlight due to its importance for food security and depleting sources. In this study, phosphorus recovery from dried sewage sludge and sludge ash by acid and alkaline leaching was evaluated. Optimum extraction time and temperature were determined as two hours and ambient temperature. Results showed the superiority of strong acidic conditions for leaching; 75 ml/g with 0.4N HCl and 25 ml/g with 0.6N HCl were determined as optimum conditions to achieve efficient phosphorus dissolution from sludge ash (94.6%) and dried sludge (91.1%), respectively, with the lower heavy metal concentrations. Lower L/S ratio put forward the dried sludge as a more advantageous resource for phosphorus extraction. Besides, by alkaline leaching of sludge ash and dried sludge, 60.3 and 70.3% phosphorus dissolutions were achieved with 75 ml/g and 1N NaOH; and the leachate was a suitable product for phosphorus precipitation due to its high pH.