Abstract

We investigated the feasibility of using Microcystis sp; blue green algae (MB) as a co-substrate to improve the mesophilic anaerobic digestion of cannery seafood wastewater (CSW) supplemented with 1% (v/v) glycerol waste (GW), to maximize bio-methane production. The MB content was set at 5, 10 and 15% (v/v) to find a near optimal methane yield. The maximum 291 mL CH<inf>4</inf>/g VS-added methane yield, corresponding to 4.4 m³-CH<inf>4</inf>/m³ - mixed wastewater, was achieved with a CSW: GW: MB mixture at the volumetric 94:1:5 ratio. The methane yield of CSW digested alone was 278 mL CH<inf>4</inf>/g VS-added (2.2 m³ CH<inf>4</inf>/ m³ of wastewater). The yields from our other experiments ranged within 81- 150 mLCH<inf>4</inf>/g VS-added. Ratios of MB: CSW exceeding 5% (v/v) gave lower than optimal methane yields. The energy content of methane from 1 m³ of mixed wastewater, with the near optimal mixture ratio 94:1:5, was 157 MJ or equivalently 44 kWh.