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Fenton/SBR组合工艺处理博落回提取废水研究
The Application of Fenton/SBR Process in the Treatment of Extracted Macleaya Cordata Wastewater
【作者】 易婷;
【导师】 李小明;
【作者基本信息】 湖南大学 , 环境工程, 2010, 硕士
【摘要】 某企业博落回提取废水往往成分较复杂、CODcr高、色度较大、可生化性差。由于废水中含残余博落回,对微生物的生长有很强的抑制作用,使得传统生物处理法很难达到预期的处理效果。在实际处理过程中,博落回提取废水即使经厌氧折流板反应器(ABR)处理后仍属于高浓度难降解废水,后期好氧处理无法正常运行。因此,有必要寻找有效、可持续的处理方法。考虑将高级氧化技术作为预处理工艺,将废水中难降解、有毒有害物质氧化成可生化降解的产物后,再利用运行成本较低的生物方法进行联合处理。这种组合工艺已经引起国内外专家的广泛关注。本文对常温25℃下Fenton与序批式活性污泥法(SBR)组合工艺处理博落回提取废水的特性进行了研究。结果表明,当进水CODcr为7300 mg·L-1时,通过多个单因素试验确定的最佳Fenton反应条件为:初始pH=3.0,n(H2O2):n(Fe2+)=15,H2O2投量为7300 mg·L-1。过高或过低的H2O2投量、Fe2+投量或初始pH值都会使氧化效果有不同程度的降低。另外,Fenton试剂的投加方式不影响水样CODcr的去除率,但搅拌速率越大,Fenton氧化效果越好。在最佳条件下Fenton处理博落回废水反应120min后,CODcr去除率为65.3%,BOD5/CODcr由原水的0.14上升到出水的0.22,可生化性得到提高。同时研究证明,出水pH不影响CODcr去除率,但SVI值随着出水pH的增大而减小。经Fenton处理后的废水BOD5/CODcr仍小于0.3,不满足可生化处理的条件,加入生活污水使其生化性得到提高。当进水CODcr值小于1000 mg·L-1时,出水CODcr控制在100 mg·L-1以下,当进水CODcr值大于1000 mg·L-1时,出水CODcr控制在500 mg·L-1以下。本文还进行了回收铁泥试验。结果表明铁泥是可以重复利用的,且试验后出水经SBR处理后满足国家三级排放标准。
【Abstract】 Extracted macleaya cordata wastewater has some typical features of pharmaceutical wastewater, such as complex ingredient, high CODcr, deep chromaticity, poor biodegradability. As the growth of microorganisms has been inhibited by the residual macleaya cordata in the wastewater, the traditional biological treatment was difficult to achieve the desired treatment effect. Aerobic process couldn’t treat successfully as a post-processing extracted macleaya cordata wastewater, which was still concentration high and refractory even after treated by ABR. Therefore, it is necessary to find effective, sustainable approach. Even though AOPs have been shown to be highly efficient, their operation is still quite expensive, especially for the treatment of highly polluted wastewater. An attractive option is a short pretreatment with an AOPs, which makes the recalcitrant pollutants biodegradable intermediates that can then be degraded in a biological process whose operation expense is much low. A combined AOPs and biological oxidation system has widespread attracted international experts’attention.The characteristics of the treatment process for extracted macleaya cordata wastewater by using Fenton/SBR combined technology was investigated at room temperature. When the CODcr concentration in the influent was at 7300 mg·L-1, the optimal Fenten reaction conditions for the process was determined through the number of single-factor test:initial pH was 3.0, [H2O2] to [Fe2+] molar ratio was 15, and H2O2 dosage was 7300 mg·L-1. In addition, Fenton reagent dosing method could not affect the CODcr removal rate, but as the stirring rate increased, the CODcr removal rate improved. Under those conditions and after 120min treatment,65.3% CODcr removal could be achieved and BOD5/CODcr was enhanced from 0.14 to 0.22, which showed the biodegredability was improved obviosusly. Meanwhile, following the treament by SBR process, the CODcr in the effluent could be controlled to less than 500 mg·L-1 (the third class national discharge standard), which indicated that this combined Fenton with SBR process could be a competitive technology for extracted macleaya cordata wastewater treatment. The research for recycling the iron sludge also has been investigated. The results showed that the iron sludge is reusable. Wastewater of the recycling process could meet the third class national discharge standard after being treated by SBR.