Anaerobic Pretreatment of Black Water with Up flow Anaerobic Sludge Blanket Reactor

Abstract:

A bench scale up flow anaerobic sludge blanket reactor(UASB) was used to pre treat black water. The objectives of the research were to investigate the removal transformation rule of organic matter in black water and methane producing properties under different conditions of temperature and hydraulic retention time(HRT). The experimental results show that the UASB reactor has a good removal efficiency on organic matters, the removal efficiency of total chemical oxygen demand is around 80%, and the removal efficiency of the suspended chemical oxygen demand and soluble chemical oxygen demand are above 90% and 40% respectively. Under the condition of HRT（10~30 h）and total chemical oxygen demand volume load rate（1.0~2.4 kg·m-3·d-1）, temperature mainly affects soluble chemical oxygen demand removal. The inflow soluble chemical oxygen demand concentration is another limiting factor of hydrolysis acidification except for temperature. For black water anaerobic pretreatment using up flow anaerobic sludge bed reactor, the HRT should better not be lower than 30 h, and the water temperature is around 30 ℃, at this point, total chemical oxygen demand, suspended chemical oxygen demand and soluble chemical oxygen demand removal efficiency are 79.1%, 91.6% and 42.1% respectively. The biochemical oxygen demand and chemical oxygen demand ratio of effluent is up to 0.60.

Key words:black water; up flow anaerobic sludge blanket reactor(UASB); hydraulic retention time(HRT); temperature; volumetric loading rate