The Design And Start-up Experiment Study Of A New Anaerobic Bioreactor

Anaerobic biological treatment technology has the advantages of lowerenergy consumption, less construction site demand, high volume loading, littleresidual sludge and energy recovery etc., and it currently is an optimaltechnology to treat high concentrated industrial wastewater. However, themainstream anaerobic bioreactors in the present market have some shortages,such as complex structures, slow start-up and long time, undesirablewater-sludge mixture, and less separation efficiency of gas-liquid-solidthree-phase, which is subject to the granular sludge culture and the design ofthree-phase separator. In order to solve the above shortages, it has a promisingfuture in the engineering applications to develop an innovative and efficientanaerobic bioreactor so as to run long-term, stably, and efficiently.This paper analyzed the key common technologies of current anaerobicbioreactors, independently developed an innovative anaerobic bioreactor ofincreasing the external backflow device, and making the packing layercomponents to substitute the traditional three-phase separator throughoptimization designs, and then researched the hydraulic characteristics andstart-up process of the reactor. The main contents of this paper are presented asfollows：(1)The new designed anaerobic reactor was made from transparent organicglass,1000mm in diameter, total height1600mm, the total volume1200L. Thebottom of the reactor adopted the shoot water distributor, the sludge areaincreased the external backflow device, the top of the reactor adopted thepacking layer components in place of the traditional three-phase separator, inorder to realize the original design concept.(2)The clear water experiment alialyzed the hydraulic characteristics of thereactor in continuous stirred conditions, the test results showed that flow mixtureinside the reactor was good, similar to the completely mixed state. And the reactor internal dead zone rate was small, so its effective capacity wasconsiderable.(3)With soluble starch wastewater as matrix, start-up experiment of the newanaerobic bioreactor was studied. The whole process could be divided into threestages: experimental starting, acidification controlling and restarting. In theconditions of normal temperature and intermittent mixing the new anaerobicreactors, its start running effects were investigated, the average COD removalefficiency of the reactor could be above60%, the pH, alkalinity and volatile fattyacids in the effluent in the test process could remain stably, which illustrated thatthe reactor could operate stably. Furthermore, the intermittent mixing to thesludge in the sedimentation area could accelerate the separation of methane gasin the reactor, at the same time also could promote the separation ofmicro-bubbles in the sludge.(4)The self-made packing layer components, which replaced the traditionalthree-phase separator patent technology, had simple structure, convenientinstallation, and could reduce the project cost. The SS of effluent was lower than300mg/L during the restarting experiment proeess, which meaned that thepacking layer components could reduce the sludge loss, and made the separationof sludge water have good stability.