The Effect Of Brown Sugar Content On The Stable Operation Of UASB Reactor

As a kind of clean, efficiency energy, hydrogen has gained more focus all around the world. Biological hydrogen production has no fossil energy consumption, low cost advantages, so as to conform to the requirements of the development of new energy.The Up-flow Anaerobic Sludge Blanket (UASB) is high activity sewage treatment in the reactor, simple and high processing efficiency of system device has a broad application prospect. In this paper, the Brown Sugar was used as the substrate of UASB reactor, to prove the feasibility of the reactor for Biological Hydrogen Production, discussed the startup of the reactor, running characteristic, and studied different concentrations of brown sugar content which had influence on the stable operation of UASB reactor.This paper use the brown sugar to simulate sewage water as the substrate, add to NPK as nutrient elements, control of temperature in the reactor in (35plus or minusl)℃, HRT (Hydraulic Retention Time)8h. In the startup stages of control the COD concentration in1000mg/L, after30days start to finish. After the start to adjust it to4500-6000mg/L, discussed the stable operation characteristic of UASB reactor. Finally studying the influence of organic load UASB Biological Hydrogen Production by changed the simulation of brown sugar content in the sewage water. The experiment lased for150days, the reactor system of UASB after start to stable operation to a system crash during the test, the ethanol type fermentation was realized when internal environment in the phase of stable operation.In the startup stages of the engineering parameters were different degrees of change, the removal rate of COD by less than10%to40%, gas production increased from0to10L/d, ORP value by around minus220mv fell to minus400mv, and outlet water pH value around fell to between4.5～5.0. By mixed fermentation type fermented into ethanol type fermentation.Stable operation stages of the engineering parameters are relatively stable, the highest removal rate of COD reached40%, and ORP steady at just minus380mV to minus440mV. Inflow water pH from6.75to7.25, outlet water pH value remains between4.5～5.0. The highest production rate of gas reached27.040L/d, the hydrogen content in more than50%. In the terminal liquid products, ethanol and acetic acid in the volatile acid proportion is very big in the total amount, and maintains fluctuation steadily in the range of80%～85%, and ethanol is significantly higher than the content of acetic acid, propionic acid and butyric acid, which formed typical ethanol type fermentation.In the process of brown sugar content increased in simulate sewage water, the reactor system of organic load impact (COD concentration) increased gradually, until beyond system organic load under impact scope, system crash experiment is over. Inflow water of brown sug- ar content at2.5mg/L, the production rate of fermentation gas reached maximum, the removal rate of COD reached highest, which illustrate this brown sugar concentration is the most suitable for hydrogen producing bacteria survive, more than4mg/L hydrogen producing bacteria began to a large number of death, causing system crash embodied in COD removal rate is reduced, producing hydrogen reduction, in the terminal liquid products, not only ethanol content is greatly reduced but also lower than other kinds of acidic products, which formed typical ethanol type fermentation into other types of fermentation.Through this research, the paper proposed treatment process of UASB reactor which combined biological treatment technology of organic wastewater with energy recycling mixing process, not only strengthen the function of anaerobic treatment but also can use the energy effectively, which is one of the development directions of waste water treatment technology and has high engineering application value. But while this experiment proved that the feasibility of UASB reactor for anaerobic biological hydrogen production, but the distance will be industrialization is still a long way to go, need to each influence factor, for more in-depth research about the structure of the reactor, the composition of the substrate and types, etc.