Anaerobic Baffled Reactor For Treatment Of Sweet Potato Starch Wastewater

The anaerobic baffled reactor (ABR) which is a new form and high efficiency reactor was initially developed by McCarty and Bachmann in 1982. ABR is rather embody the idea of SMPA wastewater treatment and has more super characters than other reactors.It is studied in this paper that sweet potato starch wastewater which has high COD and better biodegradability and degradability treated by anaerobic baffled reactor is studied in this paper. Sweet potato starch wastewater is produced through simulating produce technology in this experiment. According to the seasonal production characteristic of the sweet potato, technology characteristic of treating sweet potato starch wastewater by ABR is studied in detailed, mainly as follows:1. According to the practical fact and research, ABR physical model in room and its running system in 33℃ is designed;2. The first start-up of ABR is studied;3. Technology characteristic of ABR in treatment sweet potato starch wastewater is studied. In this stage, the parameter such as gas amount effluent VFA, effluent VFA of different sector, effluent COD, effluent COD of different sector and alkainity which reflect effection of treatment are measured and analyzed in system;4. Reactor acidification and comeback are studied;5. The secondary start-up of ABR is studied;6. Engineering simulating design and economics technology analysis are studied, which establish a foundation for further practical engineering design.The study results of this paper indicate:1. The reactor can start-up in 20 days and the COD removal rate of ABR is over 90% steadily if we use anaerobic sludge which has better granulation and can adapt to the change of the food as inoculation sludge;2. The main methods of restraining and reducing channel flow: control hydrodynamic retain time, because short HRT can make stream speed ratio faster andcause channel flow phenomenon; better design leading flow board, which can make stream divide equally at the bottom of ABR and reduce channel flow in maximum.3. The best technology conditions through experiment is that: cubage loading is 12.0 kgCOD/(m3 ? d), HRT is 60h, when the COD removal ratio is 94.3%.4. COD removal efficiency is dissimilarity in different compartment of ABR because of different COD and HRT of influent. When influent COD is about 12000mg/L and HRT is 12h or 48h or 72h, COD removal efficiency in third compartment of ABR is the highest and producing methane phase takes place in this compartment. When HRT is 12h, COD removal efficiency in different compartment is lower than HRT is 48h and 72h. It indicates that COD removal efficiency is lower if HRT is too short and COD removal efficiency will increase if HRT is extended.5. The characteristics of hydrolysis acidification process and controlling approaches in ABR reactor is reported. In the initial phase, pH raises, COD and VFA drop in sequence from one compartment to other, which are the remarkable characteristics of two-phase anaerobic digestion process. In the entire hydrolysis acidification period, pH in each compartment decreases to 3.5 — 4.5 and keeps constant, and COD content in influent is close to that in effluent. The experiment indicates: The reactor will not return to normal condition if acidification not be remedy in time. By adjusting alkaline only or organic load only, the system could not be recovered. However by adjusting alkaline and organic load simultaneously, the system could gradually return in 20 days.6. Secondary start-up time of ABR is short and can return completely in 10 days after ABR stopping 1 month. It is shown than the reactor adapts to the intermissive production of sweet potato.