Research On Treatment Of Sucrose Wastewater By Process Of ABR-BAF

As a sugar province of China, Guangxi discharges wastewater into river and makes this kind of organic wastewater be another major pollution source, while refining much sugar. For the purpose of reducing environmental pollution that caused by sucrose wastewater, the feasibility of technical application is investigated in this thesis about treating sucrose wastewater by combined process of ABR-BAF. It shows that this combined process has a good deal with the effects of treating sucrose wastewater through the research of start-up, operation, kinetic analysis of anaerobic and microorganism ecology.It was used that the artificial wastewater added alkalinity and trace elements in the start-up phase. The CODcr of influent was increasing from 1200mg/L to 2400mg/L gradually with the temperature of (32±1) Degrees Celsius, HRT=24h and pH maintains at 7.9-8.2. After 68 days, the removal rate of ABR stabilized above 90%; It was showed that volatile acid concentration was 22.69mmol/L at the most and alkalinity concentration at the lowest, only 10.69mmol/L in the first compartment; The fourth and fifth compartment had the higher levels of coenzyme F420, and good methanogenic activity. The total amount of EPS were above normal in the first, fourth and fifth compartment; The clear granular sludge and flora form could be known from the photo of SEM when the start-up was successful and also it was showed that the methanogenic bacteria in the compartment behind were more active through the small bottle of static batch experiments.The actual sucrose wastewater was used in the operation phase. The results showed that: The load was increasing from 1355mg/L to 2955mg/L gradually with the temperature of (32±1) Degrees Celsius, HRT=24h, the removal rate of ABR stabilized at 91.8%-96.2% and pH maintains at 6.6-7.1. In the process of operation, the first compartment was impacted the biggest impulsion, and volatile acid concentration was 9.33mmol/L at the most and alkalinity concentration at the lowest, only 19.25mmol/L in the first compartment; The fifth compartment had the higher levels of coenzyme F420, with good methanogenic activity. The total amount of EPS were above normal in the first and third compartment; It was showed that bacteria were stable in every compartment through the photo of SEM and the small bottle of static batch experiments.The CODcr concentration was maintained at 3500mg/L without NaHCO3. After 6 days, the reactor was completely acidification with no signs of natural recovery. The CODcr removal rate was only 5.6%-6.0% while pH was under 5.0 in all compartments. At the same time, it was showed that there was a decrease in the methanogenic activity through the comparison with before and after the acidification, the gas volume in the first and fourth compartment was zero; The coenzyme content was less and EPS was more than that of before acidification. After acidification it was showed that the variation of the number and the species of bacteria before and after acidification through MPN method and the small bottle of static batch experiments; In acidification phase, there were a lot of Clostridium, accompanied with Micrococcus in first, second, fourth and fifth compartment.Through the comparison on the recovery effects of three control measures, it was known that regulating load and alkalinity separately had little effects on the recovery of the system, while adjusting the load and alkalinity at the same time was better. The CODcr removal rate rised to 86.2% with the pH value 6.6-6.7 which reached the level before acidification.The model equations of ABR on treating sucrose wastewater were calculated through the material balance equation and the inhibition dynamic equations.There were four equations corresponding different sludge loading,0.178 kgCOD/kgVSS·d, 0.253 kgCOD/kgVSS·d,0.295 kgCOD/kgVSS-d and 0.351 kgCOD/kgVSS·d.The natural biofilm formation method was used to start BAR Controlling the water flow rate 1.5L/h, after 3 days, there was a visible thin layer of flocculent biofilm on the surface of filler, after 12 days, start-up was complete with the CODcr removal rate 74.9%. The Biomass and biological activity were 3.59×108/g(filler) and 0.186mgO2/g·h respectively.The best conditions were:HRT was 24h of ABR with control temperature (32±1)℃, hydraulic loading was 1.59m3/m2·h with dissolved oxygen condition 5.8mg/L of BAF, and the combined process of ABR-BAF could complete the start-up and operation stably, increasing the wastewater load from 1.2kgCOD/(m3·d) gradually to 3kgCOD/(m3-d).