【作者】 蔡晓鸣；

【导师】 朱乐辉；

【作者基本信息】 南昌大学 ， 环境科学， 2008， 硕士

【摘要】 曝气生物滤池（Biological Aerated Filter）工艺具有体积小、容积负荷高、水力负荷大、水力停留时间短、所需基建投资少、处理出水水质好等特点,国外已广泛应用,国内也在多个行业的水处理中成功应用。近十几年来发展迅速,将成为人们控制水污染和解决污水回用问题的主要技术。本试验采用陶粒为填料所组成的曝气生物滤池,模拟生活污水和含油废水,分别考察了曝气生物滤池的挂膜启动以及水力停留时间、水力负荷、有机负荷、初始油浓度等对曝气生物滤池处理含油废水效果影响,并结合有关文献资料,取得结果如下:1、曝气生物滤池接种挂膜试验表明:HRT为4h、气水比为3:1、水温保持在9℃以上,经过20d生物膜即可成熟,NH₄-N和CODcr去除率分别达到65%和75%左右。其中稳定硝化生物膜形成慢于异养好氧生物膜,实际表现为对氨氮达到稳定的去除率和达到稳定的CODcr去除率相比,晚7～10d。2、曝气生物滤池对污染物的去除沿滤层高度呈现出不同的特点:有机物CODcr的去除主要发生在滤层的前半部分（即距进水端60cm段）,和CODcr沿程去除情况稍有不同,NH₄-N的去除主要在生物滤池距进水端的20cm～80cm段。3、曝气生物滤池处理油试验表明:在进水CODcr浓度在0～450mg/L的范围内,气水比为4:1,水力停留时间、有机负荷、初始油浓度等是影响油去除效率的重要因素。水力停留时间（HRT）越长,出水油浓度越低,处理效果越好。只要保证曝气生物滤池的水力停留时间在3h以上,油去除率就能维持在75%以上。当HRT为8h时,油平均去除率为90.19%,出水油在1.48mg/L左右。随着水力负荷的增大,油的平均去除率随之下降,呈负相关。因此在实际过程中,要保证合适的水力负荷获得较好的处理效率。有机负荷在0～2.79kgCODcr/（m³·d）范围内,且HRT为4h时,曝气生物滤池对CODcr和油都有较好的去除效果,出水CODcr和油浓度分别低于77.40mg/L和5mg/L,油的平均去除率在80%以上。初试油浓度为0～10mg/L,曝气生物滤池处理效果最好,出水CODcr和油浓度分别低于50mg/L和1mg/L,除油率在90%以上;油浓度超过30mg/L时,反应器处理效率显著下降;油浓度超过50mg/L时,系统有失效的迹象出现。4、曝气生物滤池的冲击负荷试验得出:在水温12～19℃,气水比为4:1,水力停留时间4h,进水油浓度为0～20mg/L,CODcr浓度在0～300mg/L的稳态运行情况下,曝气生物滤池对CODcr的冲击负荷比油的冲击负荷耐受性要强。5、反冲洗试验研究表明:滤池的运行周期为6～7d,反冲洗采用气水联合形式,具体为单独气洗4min（反冲洗强度0.46m³空气/（m³填料·min））→气水联合反冲洗5min→单独水洗6min（反冲洗强度0.18m³水/（m³填料·min））,整个反冲洗历时15min。BAF反冲洗后可以较快恢复到最佳状态,冲后2h就已接近正常水平,3小时可以恢复到最佳处理水平。更多还原

【Abstract】 BAF has many advantages,such as small volume,little covering earth and hydraulic retention time(HRT), high treatment efficiency and effluent water quality,low investment and running cost etc.BAF has been used widely for many years in the world and been used to treat several wastewater in our country.In this paper, BAF with expaded clay media was studied on the treatment of oil wastewater.The biofilm colonization of BAF was observed with simulativing sewage and the effection of the BAF treating oil wastewater was studied on HRT, hydraulic loading, organic loading, initial oil concentration. The main results are summarized as folows:1. BAF has good performance in treating wastewater,when the HRT is 4h, the ratio of gas to liquidis about 3: 1 ,the biofilm colonization would mature in 20 days, and the removal rate of COD、NH4-N is probably 75%,65%,respectively.The stable nitrificated biofilm colonization grew more slowly than the heterotrophic aerobic biofilm, which was performed as the stable removal rate of NH4-N was reached later 7～10 days than the COD’s.2. The removal of pollutants showed different characteristics along with the high height in Biological Aerated Filter:for along the filter the removal of organic matter CODcr mainly occurred in the filter of the first part (that is 60 cm from input), and which is different from the removal CODcr, the optimum media height for the removal of the NH4-N was mainly 20 cm～80cm from the end of the output.3. The oil processing tests show that: HRT, organic load, the initial concentration of oil played very important fact on the oil removal when the CODcr varied from 0～300mg/L and the gas-water ratio was 4:1 .When the HRT was longer, the oil concentration of output was lower., the average oil removal rate was 90.19% when the HRT was 8 h ,and oil content in output was about1.48 mg / L . As long as the HRT was more than 3 h, the oil removal rate can be maintained above 75%. With the increase of hydraulic loading, the average removal rate of oil declined in gradually and negatively correlated. Therefore in the actual process, appropriate hydraulic loading ensured a better efficiency.The BAF had a high removal rate on oil and CODcr When the organic load was 0～2.79 kgCODcr / (m~3·d) and the HRT was 4 h.The CODcr and oil concentrations of effluent were lower than 77.40mg / L and 5 mg / L, respectively.The average removal rate of oil was more than 80%.When the initial concentration of oil was 0～10mg/L, Biological Aerated Filter had a best result.The effluent CODcr were lower than 50 mg/L, oil were lower than 1 mg/L, and the removal rate of oil was more than 90 %.when oil concentration exceeded 30 mg/L, the efficiency of the reactor dropped significantly. The system would turn out of useless a sign when oil concentration was beyond 50 mg/L.4. The influent load will affect the performance of BAF directly. The results of the experiment show that the BAF has better capability to CODcr impact than to oil impact when the stable situation was chosed as: the CODcr was between 0～300 mg/L, the oil content ranked 0～20mg/L, the ratio of gas to liquid about 3:1, the HRT was 4 h with the temperature varing from 12 degree to 19 degree.5. Backwashing pilot study showed that: the filter running cycle was 6～7 days. Gas -washed was along with water-washed.The backwashing way was showed as:a separate gas washing 4 min (backwashing intensity 0.46 m~3 gas/ (m3media·min))→water and gas joint washing 5 min→separate washing washed 6 min (backwashing intensity 0.18 m~3 water / (m~3 media·min)), the whole backwashing lasted 15 min. the optimum condition of BAF would return rapidly after backwashing .It would been close to normal levels after 2 h, three hours could be restored to the best level of treatment.更多还原