【作者】 叶芬霞；

【导师】 陈英旭； 冯孝善；

【作者基本信息】 浙江大学 ， 环境工程， 2004， 博士

【摘要】 活性污泥法是目前世界上应用最广泛的污水生物处理技术，但它一直存在一个最大的弊端，就是会产生大量的剩余污泥。本文针对我国目前已逐渐暴露出来的污泥出路问题，利用在质子载体存在下或发生好氧—缺氧循环时，生物发生合成代谢和分解代谢的解偶联，造成的能量泄漏反应使生物的生长速率下降的生物化学机制，通过物理、化学、生物等手段，主要依靠降低微生物产率以及利用微生物自身内源呼吸进行氧化分解，使污水处理设施向外排放的生物量达到最小，从根本上、实质上减少污泥量。首先比较筛选了对污泥的减量化效果好、价廉、无毒的化学解偶联剂；在此基础上，研究了添加3，3′，4′，5-四氯水杨酰苯胺(TCS)的分批活性污泥工艺的剩余污泥减量化效果，以及对工艺运行效能和污泥性能的影响；着重进行了添加TCS的活性污泥工艺、好氧—沉淀—缺氧(OSA)工艺、添加TCS的OSA联合工艺的连续运行试验研究。 对邻氯苯酚(oCP)、间氯酚(mCP)、2，4-二氯苯酚(DCP)、2，4，5-三氯酚(DCP)、对硝基苯酚(pNP)、间硝基酚(mNP)、2，4-二硝基苯酚(DNP)和TCS 8种化合物的污泥减量化效果进行的比较研究表明，8种化学物质均是较好的代谢解偶联剂，都能有效地控制污泥产率。硝基酚类化合物优于比氯酚类化合物，其中DNP和pNP的效果最好，控制率分别为89.16％和83.77％。oCP、TCP、mNP和TCS的污泥产率控制率也达到60％以上。各种代谢解偶联剂效果的差异与其酸性大小有关，pKα值越低，污泥的减量化效果越好，这证实了解偶联剂所造成的产生ATP质子动力势(pmf)弱化的理论分析。解偶联剂使污泥产率下降的最佳浓度基本都在十几ppm左右。解偶联剂浓度固定不变时，随污泥浓度的升高，污泥产率逐渐提高。高污泥浓度将弱化解偶联剂的效果，因此认为采用比解偶联剂浓度(解偶联剂浓度／污泥浓度)来选择解偶联剂更为科学合理。 研究了在分批间歇式活性污泥工艺中，投加液体TCS、固体TCS和固体TCS的投加方式对剩余污泥的减量化效果以及对工艺运行效能和污泥性能的影响。连续40d的分批运行结果表明，3.6mg／l TCS能降低污泥产量54.3％，而基质的去除能力没有受到影响，出水的总氮和氨氮浓度和对照相当。污泥的SVI略微有些增大，和对照相比污泥较疏松，但污泥的沉降性能未见有影响。污泥的比氧气消耗速率(SOUR)和脱氢酶活性都比对照污泥要高，说明TCS对污泥中的微生物有激活作用，促进能量泄漏，这是造成污泥产率降低的原因所在。经过40d的运行后，在对照反应器中，仍有丝状菌存在，而添加TCS的反应器中的污泥中丝状菌则很少。分子生物学手段(PCR一DGGE)检测表明污泥中的细菌种群结构也发生了改变。TCS以固体方式投加的效果好于液态投加，但污泥的COD去除能力有所下降，出水的总氮和氨氮含量和对照相当，污泥的SVI值升高，但不至于严重影响污泥的沉降性能。在总投加量相同的情况下，一次性投加比分批小剂量投加对污泥的减量化效果要好，COD的去除率受到了一定的影响，随剂量增高，影响程度越明显，最高剂量时的COD的去除率比对照下降了12%。但出水的总氮和氨氮没有影响。污泥的SVI值也比对照要高，但污泥的沉降能力并没有受到严重的负面影响，而发生污泥膨胀。 连续运行60天的试验结果表明，每天投加TCS 40 mg，合建式完全混合活性污泥工艺中的剩余污泥产量下降30%，工艺的COD去除能力和污泥的沉降性能未受明显影响。但出水中的氨氮和总氮浓度增大了约16一18%。同时发现污泥的SOUR值提高，说明化学解偶联剂可使微生物，尤其是细菌的呼吸速率得以提高。添加TCS系统中的污泥，原生动物和后生动物种类和数量减少，而且活I险较低。污泥中丝状菌较多，污泥较松散。微生物的种群结构也发生了改变。 添加TCS的传统活性污泥工艺、OSA工艺以及两者的联合工艺的180天连续运行发现，3种工艺的剩余污泥产量均较对照工艺低，联合工艺的污泥的减量化效果最好，其次是添加TCS的传统活性污泥工艺，最后是OSA工艺。污泥产量分别比对照下降46.90%、33.99%和25.94%。和对照的传统活性污泥工艺相比，3种工艺的COD去除能力并未受很大影响，但出水中的氨氮浓度上升，总氮去除率也有一定程度的下降，同时发现3种工艺能使污泥的吸磷能力增强。TCS的加入使污泥的SVI值上升，但OSA工艺能改善污泥的沉降性能。虽然单独添加TCS的活性污泥工艺和OSA工艺国外都有报道，本试验结果也与他们的研究结果相似，但TCS和OSA的联合工艺目前国内外都未见有报道。这为在活性污泥工艺中开发剩余污泥的减量化技术提供了一条新型技术途径。 大肠杆菌E.coli K12菌株的对数生长培养物经氯霉素处理后，热产量下降，但即使生长停止，产热速率仍可达0.22协W/陀蛋白质。葡萄糖耗尽后，无热量产生。说明这种与生长无关的能量泄漏并不仅仅是由于内源代谢所致。当培养在无氮，但含有过量葡萄糖的静息培养基中时，热量产生速率可达 0．15卜W…g蛋白质。莫能霉素和3，T，4”，5一四氯水杨酸苯胺（nS）可使热量增加两倍。二环己基碳酸亚胺（DCCD）则可消除与生长无关的热量更多还原

【Abstract】 Worldwide, the activated sludge process is in common use for the treatment of wastewater, which also generates a large quantity of excess sludge daily as a byproduct that requires additional processing and disposal and may account for up to 60% of total plant operation costs. In this paper, based on the increasing severe problem of sludge ultimate outlet, uncoupled metabolism under the presence of protonphore or aerobic-anoxic recycle occurs and dissipating energy intended for anaboiism of cells mass provides a direct mechanism for reducing the yield of biomass. Reduction of yieid of cell and lysis of cell by endogenous respiration with physical, chemical and biological means result in low to zero excess sludge discharge from wastewater treatment plant. This method can reduce sludge production radically and virtually. The effectiveness of eight metabolic uncouplers in reducing sludge production from activated sludge process were compared to screen effective, cheap and non-toxic available uncoupling chemicals and determined the long-term uncoupler effects of 3,3’,4’,5-tetrachlorosalicylanilide(TCS) in activated sludge batch cultures. The effects of addition of TCS on process performance and sludge characteristics were also investigated. The activated sludge process with addition of TCS. oxic-settling-anoxic(OSA)process and OSA with addition of TCS combined process were studied in continuous operation with emphasis.In the second chapter, effects of 8 uncoupling chemicals[ o-chlorophenol(oCP), m-chlorophenol(mCP), 2, 4-dichlorophenol]DCP), 2, 4, 5-trichlorophenol(TCP), p-nitrophenol(pNP), m-nitrophenol(mNP), 2,4-dinitrophenol(DNP) and TCS] on cell yields in batch cultures were compared and found that all eight chemicals are good uncouplers in reducing sludge yield. Nitrophenol chemicals were better thanchlorophenols. The two chemicals DNP and pNP were the most effective uncouplers of activated sludge respiration with control rates of 89.16% and 83.77% respectively. The control rates of oCP, TCP, mNP and TCS were also more than 60%. The acidity constant(pATa)of a metabolic uncoupler highly influenced its effectiveness in sludge reduction, i.e. metabolic uncoupler with a lower pKa value has a higher potential to reduce sludge production which confirmed the theoretical analysis that uncoupler weaken the proton motive potential producing ATP. The optimal concentrations of uncouplers reducing sludge yield were about 10 ppm. When the uncoupler concentration was constant, sludge yield increased with the increasing sludge concentration. High sludge concentration would weaken the effect of uncoupler. Therefore, the specific uncoupler concentration, i.e. the ratio of uncoupler concentration to sludge concentration was a better parameter to choose uncoupler.In the third chapter, the effect of addition of liquor TCS, solid TCS and addition mode of solid TCS on excess sludge production in batch activated sludge process, process performance and sludge characteristics were investigated. The results of 40 day batch operation demonstrated that TCS of 3.6 mg/l can reduce sludge production by 54.3%, but substrate removal rate was not inversely influenced and effluent total nitrogen and NH3-N concentrations were comparative with the control test. SVI values of sludge were increased slightly. Although compared with the control sludge, the sludge was loose; the settlability of sludge was not affected. Specific oxygen uptake rate(SOUR) and dehydrogenase activity of sludge were higher than those of control sludge, which showed that TCS can activate microbial in sludge to promote energy spilling which resulting in sludge yield reduction. Filamentous bacteria were still present in the control reactor, while this did not occur in the reactor with addition of TCS. The results of PCR-DGGE technology suggested that the microbialpopulation was changed. The effect of dosing solid TCS was better than that of liquor TCS. but COD removal rate was decreased a little. Effluent TN and NH3-N concentrations were the same wi更多还原