Acf Based Soft Structure Bireactor Design And Its Application On High Concentration Organic Wastewater

The coking wastewater contains much non-biodegradable organic matter. It is still difficult to reach a satisfactory result, although many treatments to coking wastewater have been studied in recent years. In addition, with the improvement of coking wastewater discharge standard, current mainstream technologies, such as A2/O, A/O and other treatments, are difficult to reach the discharge standards.Reform A1stage of the A2/O craft and propose a new idea about soft structure anaerobic baffled reactor in this thesis. Use ACF as the internal baffle materials in ABR, design the reactor’s structure and size, and study the hydrodynamic characteristics of the soft structure reactor; Study the influences of activated carbon powder’s factors, such as particle size, specific surface area, adsorption value, dosage and so on, and study granular sludge characteristics(mechanical strength, settling velocity, apparent structure and microscopic characteristics).As to observe granular sludge’s treatment effect on coking wastewater, introduce aerobic granular sludge technology in O segment; Build a small, combined and integrated system, which combines ACF-ABR with A/O-MBR. Study the craft’s treatment effect on high concentration organic wastewater (coking wastewater) by GC/MS analytical technique. The main test processes and results are as follows:(1)The study of new soft structure anaerobic baffled reactor:using a self-made anaerobic reactor in experiment, whose A1segment is reformed by ACF-the main material of the reactor’s interior. a. the study of clean water hydraulic characteristics:measure the tracer residence time distribution of reactor under different conditions by tracer experiments. The result shows that plug-flow phenomenon in the reactor become apparent gradually with hydraulic retention time increasing as well as the number of cell room. By comparing, the N value of the ACF-ABR is larger than the plexiglass baffle reactor under the same condition, such as same hydraulic retention time and number of cell room. It also shows that the plug-flow effect of ACF-ABR is better than plexiglass baffle reactor. b. the study of coking wastewater treatment performance with ACF-ABR: dosing800ml anaerobic sludge into the soft structure anaerobic reactor which is taken from Wuhu Xinxing Ductile Iron Pipes Factory. The system starts successfully after sludge incubation period, sludge acclimation period and stable operation period. The removal efficiency of COD and NH4+-N are obvious during the stable operation period, the average removal rates respectively is41.2%and76.9%; Water biodegradability improved significantly, the B/C value increase from0.21to0.35, the fluctuation of COD and NH4+-N both decrease by17%and69%.(2)The study of aerobic granular sludge’s culture conditions and characteristics:use conventional activated sludge as seed sludge, and use simulated soybean milk wastewater to cultivate aerobic granular sludge in the SBR reactor. Dosing500ml flocculent sludge into each SBR reactor to synchronize cultured, which has been activated. A cycle is12h, water changing rate is50%. Study the effect of aeration intensity and activated carbon powder’s particle size on granular sludge’s formation. Experimental result shows, the best particle size of activated carbon powder is140mesh, rising velocity is1.40cm/s, settling time is2min. Under this best condition, aerobic granular sludge form most, particle size distribution is most concentrated. The mature aerobic granular sludge is almost round and oval, having a clear outline, with carbon particles on surface and in interior; granular sludge is compose of many intertwined filamentous bacteria and a large number of bacteria. The internal structure is pore and layered. It has facultative anaerobic cocci inside. The aerobic granular sludge has good mechanical strength. The average settling velocity is48.48m/h, which is more than5times of the conventional activated sludge. When the sludge all become granule, COD load can be2.6～3.2g/L·d and COD removal rate can reach to70～94%.(3)the investigation of O-MBR craft effect:curtain PP hollow fiber membrane is made by Wenzhou Yueqing Teng Xiang Mo Technology Co., Ltd, whose pore size is0.1～0.2μ.m and area is0.2m2. Experimental results show, the MBR system shows good removal efficiency of COD and ammonia by membrane barrier and biodegradation. With the Experiment carrying on, microbe proliferate largely in the reactor, so making the sludge concentration increase continuously in O segment. The organic removal rate improves gradually in the reactor with sludge concentration increasing. The removal rate of COD and ammonia nitrogen both increase gradually. The COD and ammonia nitrogen content in effluent respectively reduced to36.9mg/L and6.9～14.3mg/L. By analyzing, MBR membrane removes some suspended and larger molecule organic matter by interception. Thus reduce the COD of effluent largely, and improve COD removal efficiency; The ammonia removal is mainly by microbial nitrification and denitrification in A/O segment, membrane rejection acts a very small role in the removal process.(4)The coking wastewater treatment by combined crafts: ABR-A/O-MBR combined craft runs at room temperature (25～35℃). Experimental results show:ACF as baffle material, not only achieve changing the flow direction of traditional ABR, but also have an adsorption to pollutants. It also makes the particulate matter and macromolecules pollutants have different enrichment degree in the reactor.The pollutants degradation characteristics in each step of ABR-A/O-MBR are analyzed by GC/MS:the pollutants in coking wastewater include phenols, benzene, nitrogen-containing heterocyclic compounds, petroleum hydrocarbons, esters, acid and alcohol, phenolic content is highest. Phenols, quinoline, pyridine, indole, naphthalene and other nitrogen-containing heterocyclic compounds in the wastewater began to degrade to petroleum hydrocarbons by the treatment of soft structure bioreactor. The B/C value increase from0.21to0.35, the biodegradability is improved significantly; Majority of phenolic is degraded completely in hypoxic and aerobic segment, acids and other organic matter are begin degraded, but the long-chain alkanes, esters, alcohols, halogenated hydrocarbons and amines are still can’t be biodegrade.