No abstract

No abstract

No abstract

The study investigated the unbiodegradable fraction of particulate chemical oxygen demand (PCOD) in thickened waste activated sludge (TWAS) using semicontinuous-flow completely-mixed anaerobic digesters. A laboratory-scale semicontinuous stirred tank reactor was used to investigate TWAS anaerobic biodegradability at hydraulic retention time of 16.7 d to 33.3 d and organic loading rate (OLR) of 1.21 kg COD/m3•d to 3.47 kg COD/m3•d. The COD and volatile suspended solids (VSS) removal for TWAS were 37% to 44% and 39% to 42% at an OLR of 1.27 and 3.47 kg COD/m3•d, respectively. Using a biomass yield () of 0.29 g COD biomass/g COD substrate, decay rate (of 0.015 d-1; and a solids retention time (SRT) of 16.7 d; two linear fits correlating the difference between effluent biomass; and effluent particulate COD with influent total COD, the unbiodegradable fractions of PCOD and VSS were estimated from the slopes of the linear fits to be in the range of 0.26 to 0.28.

No abstract

No abstract

No abstract

This study evaluated the flocculent settling in water and municipal wastewater (MWW) in a 10.6 ft deep column. A total of eight runs at three different testing conditions involving MWW alone, food waste (FW) alone, and FW in MWW (FW+MWW) were conducted. Total suspended solid (TSS), total BOD (TBOD), total COD (TCOD), total nitrogen (TN), and total phosphorous (TP) removal efficiencies after 3 hours of settling were 62%, 46%, 49%, 46% and 62% for FW, and 50%, 43%, 39%, 37% and 24% for MWW. Removal efficiencies of particulate COD (PCOD) and particulate BOD (PBOD) at the lowest surface overflow rate (SOR) of 1.1 m3/m2/hr corresponding to the longest settling time of 3 hours were 59% and 64% for FW, and 65% and 70% for FW with MWW samples. On the other hand, no significant variation between FW and FW with MWW was observed for PN removal after 3 hours of settling.