| Papermaking wastewater takes a large proportion in industrial wastewater., which is difficult to be treated with high cost because of its complex components, high pollutant concentration and poor biodegradability. Especially, straw pulp wastewater is more difficult to be treated. Therefore, we study on its treatment technologies to find an effective and feasible process, which is important and promising for the development of environmental protection and paper industry.This study designs for the treatment of middle stage waste water of a straw pulp making factory in Shandong province, and uses complex water distribution aeration+ anaerobic fluidized bed of cloth water pulse+aerobic+deep treatment process, through careful research information collection, detailed analysis of the resources, water quantity and quality characteristics, and comprehensive comparision of corresponding domestic wastewater treatment technologies.From development and reaction mechanism of anaerobic fluidized bed of pulse water distribution, the paper analyzes its advantages:(1) Reactor structure is simple without mechanical mixing device and special consideration of gas-liquid-solid separator, the investment and running costs is lower; (2) The waste water flows from the bottom up, with low average speed and good separation effect of sludge and water; (3) Pulse water distribution increases the mixing of microbial sludge and wastewater, and improves the treatment effect and stability; (4)The micro-organisms in reactor have well-stratified population and obvious layer distribution, the carrier improves sludge volume and sedimentation, which can effectively retain microbial activitive sludge inhigh load condition; (5) Co-exist of granular and flocullent sludge improves the adaptability with lower sludge production and less surplus sludge; (6) It has better capability for high water load and organic shock, and strong endurance for toxic and harmful substances in the influent; (7) The systen can be rapidly and directlly started through biological sludge floc, with convenient operation and management.The author designs the aeration tank, flow sedimentation tank, anaerobic fluidized bed of pulsed water distribution system, analyses the quality of influent and eflluent water. (1) Temperature is one of the main factors for removal rate, the removal rate decreased nearly 10 percentage when temperature decreased, temperature affects the height of sludge interface, and we can achieve efficient operation at low temperature in winter though pre-aneration in sedimentation tank; (2) COD removal rate decreased when volume load is raised, and increased when volume load is lower; (3) The removal rate is lower if sludge load is higher, otherwise increased; (4) The effluent COD has closely relation with the VFA, anaerobic inhibitation results effluent deterioration; (5) COD removal rate is high if HRT is high in anaerobic tank, otherwise lower.The process combined with aerobic + Fenton pulp papermaking wastewater treatment can reduce aerobic running costs and improve water quality, water can be achieved is less than COD<60mg/L, by adjusting the process parameters low as COD<30mg/L, reached any standard domestic paper industry requirements. And can achieve some reuse.The author finally puts forward some proposals. 1.Use anaerobic sludge inoculation to reduce debugging time in similar projects.2. Gas pressure test should be done to avoid leakage.3.It is better to reduce temperature loss in previous process to avoid anaerobic inhibition.4. Following track and analysis shoud be done in order to get more understanding on features of middle stage straw pulp waste water treated by anareobic process.5. Ramps and high precipitation areas should be set up in upper part of the pool to increase microbial population and improve removal efficiency. |
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