Performance Study Of Low Intensity Ultrasound Strengthen Anaerobic Baffled Reactor Treating Sewage

As an efficient anaerobic biological treatment process,anaerobic baffled reactor?ABR?not only has made a series of research in the treatment of high concentration organic wastewater,but also has getten more and more attention in the treatment of low concentration wastewater.But it is faced with some urgent problems when we use anaerobic biological to treat wastewater.In the low temperature,the anaerobic microorganism grows slowly,and the degradation rate of the substrate is lower.Because of the small amount of gas production,the low efficiency of the solid and liquid mass transfer,the survival condition of the production of methane bacteria,the start-up period of the reactor.But the low-intensity ultrasound,s irradiation can effectively promote mass transfer,increase activity and accelerate cell growth,So it can strengthen the biological treatment to the wastewater,it is an effective way to enhance the efficiency of the anaerobic biological treatment to the wastewater.This task group successfully launched two groups of ABR.then designed and manufactured two identical anaerobic baffled reactor to process parallel control experiment group,the seed sludge taken from a sewage treatment plant anaerobic digester of Nanchang City,the test water is come from the artificial formulated sewage.This task group had studied two important operating parameters of the ultrasonic irradiation interval cycle and the ultrasonic irradiation treatment sludge proportion,and under the best operating parameters,we had studied the affect of the ultrasonic to the organic degradation of ABR,the VFA,the p H value,the secretion and release of EPS,the morphology of the sludge and the settling property of the sludge.And on the stable operational phase,we had studied the affect of the low-intensity ultrasound to the organic shock load resistance,hydraulic power shock load resistance and low temperature resistance of ABR.The experimental results shows that:?1?The ultrasonic irradiation interval cycle and the ultrasonic irradiation treatment sludge proportion is two important process parameters to impact the sludge dehydrogenase activity and coenzyme F₄₂₀ contents of each compartment of the ABR.Considering overall from dehydrogenase activity,coenzyme F₄₂₀ content and COD removal efficiency improvement and reasonable the economic point of view,the best choosen of the ultrasonic irradiation interval cycle is 24 h.When the ultrasonic irradiation treatment sludge proportion is 10%,compared with the control group,the dehydrogenase activity,coenzyme F₄₂₀ contents and COD removal rate in each compartment of the ultrasound group ABR is the sharpestincrease.therefore,the best ultrasonic irradiation sludge proportion is10%.?2?The average removal rate of COD,the average removal rate of TN and the average removal rate of TP of the ultrasound group ABR increased 7.2 percentage points,6.8percentage points and 2.8 percentage points than the control group,the average increment rate of NH3-N decreased 5.5 percentage points than the control group.From 1# compartment to 4#compartment of the ultrasound group and the control group ABR,the concentration of VFA,the total amount of extracellular polymer,the content of protein,the content of polysaccharide,the content of DNA,and the sludge settling properties were gradually decreased,the p H values gradually increased.In the same compartment of the ultrasound group and the control group ABR,the total amount of EPS are basically the same,the content of DNA had less different.Compared with the control group,the concentration of VFA and the content of protein were increased,the p H value and the content of polysaccharide were decreased,the particle size of granular sludge was smaller,and the sludge settling performance was better in each compartment of the ultrasonic group.?3?The ability of organic shock load resistance,hydraulic power shock load resistance and low temperature resistance of ABR enhanced.When the hydraulic retention time adjusted from 8 h to 4 h,the ultrasound group ABR aheaded of four days arrival stable than the control group,ultrasound group ABR of the average COD removal rate improved 6.0 percentage points than the control group.When the influent COD was adjusted from 600 mg/L to 1200mg/L or so,the ultrasound group ABR aheaded of five days arrival stable than the control group,ultrasound group ABR of the average COD removal rate improved 5.2 percentage points than the control group.In low temperatures,the ultrasound group ABR aheaded of five days arrival stable than the control group,ultrasound group ABR of the average COD removal rate improved 8.6 percentage points than the control group,the COD removal rate was significantly improved,and the activity of anaerobic sludge also substantially increased to the condition of the control group under normal temperature,the strengthening effect of ultrasound at low temperatures is more pronounced than under normal temperature conditions.