Optimization of alkaline hydrothermal pretreatment of biological sludge for enhanced methane generation under anaerobic conditions

PERENDECİ N. A., ÇIĞGIN A. S., KÖKDEMİR ÜNŞAR E., Orhon D.

Waste Management, cilt.107, ss.9-19, 2020 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 107
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1016/j.wasman.2020.03.033
  • Dergi Adı: Waste Management
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Applied Science & Technology Source, BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Communication Abstracts, Compendex, Computer & Applied Sciences, EMBASE, Environment Index, Geobase, INSPEC, MEDLINE, Metadex, Pollution Abstracts, Public Affairs Index, Veterinary Science Database, DIALNET, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.9-19
  • Anahtar Kelimeler: Alkaline hydrothermal pretreatment, Hydrolysis, Methane generation, Process optimization, Waste activated sludge, WASTE-ACTIVATED-SLUDGE, SEWAGE-SLUDGE, THERMOCHEMICAL PRETREATMENT, ULTRASONIC PRETREATMENT, THERMAL PRETREATMENT, BIOGAS PRODUCTION, WATER TREATMENT, TREATMENT-PLANT, DIGESTION, DISINTEGRATION
  • Akdeniz Üniversitesi Adresli: Evet

Özet

© 2020 Elsevier LtdThis paper investigated the effect of alkaline hydrothermal pretreatment (HTP) on the hydrolysis, biodegradation and methane generation potential of waste activated sludge (WAS). A multi-variable experimental approach was designed, where initial solids content (1–5%), reaction temperature (130–190 °C), reaction time (10–30 min.) and caustic concentration (0–0.2 mgNaOH/mgVS) were varied in different combinations to assess the impact of alkaline HTP. This process significantly enhanced the hydrolysis of organic compounds in sludge into soluble fractions, whereby increasing the chemical oxygen demand (COD) leakage up to 200–900% with the 17–99% solubility. It boosted volatile solids (VS) biodegradation up to 40%, which resulted in a parallel increase in methane generation from 216 mLCH4/gVS to as high a 456 mLCH4/gVS methane generation basically relied on the conversion of solubilized COD. Alkaline HTP process was optimized for the maximum methane production. Optimum conditions were obtained at 190 °C reaction temperature, 10 min. reaction time, 0.2 mgNaOH/mgVS and 5% dry matter content. Under these conditions, 453.8 mLCH4/gVS was predicted. Biochemical methane potential (BMP) value was determined as 464 mLCH4/gVS supporting predictive power of the BMP model. The biodegradability compared to the untreated raw WAS was enhanced 78.2%.