Ca(Ⅱ)在活性污泥生物絮凝中的作用研究

采用4个平行的序批式反应器(SBR),研究了进水Ca2+浓度对活性污泥絮体表而特性和结构稳定性的影响,并由此来确定Ca2+在生物絮凝中的作用.结果表明:随着进水Ca2+浓度的增加,污泥中的Ca含量逐渐增大.进水中Ca2+的加入,增大了污泥絮体的粒径和密度,进南改善了污泥的沉降性能;Ca2+的加入,使可供结合的蛋白质数量最高增至近1倍,污泥表面疏水性也相应增强;污泥絮凝性能的改善,主要和可供Ca2+结合的蛋白质含量增加有关,而非多糖;EDTA通过络合污泥絮体中的Ca2+,破坏了山Ca2+架桥形成的污泥絮体结构,这说明Ca2+可通过和胞外聚合物(extracellular polymeric substances,EPS)中的负电官能团架桥来促进污泥絮体的形成并维持絮体结构的稳定性.     

生物絮凝法处理洗毛废水的研究

从活性污泥中筛选适宜洗毛废水的生物絮凝剂,并用筛选的生物絮凝进行洗毛废水生物絮凝实验。实验结果表明,当300 mL废水中生物絮凝剂投加量为5 mL、温度为20℃左右、pH值为9、反应时间45 min,搅拌采用先快速搅拌5 min后慢速搅拌40 min的条件下絮凝效果最好,对COD和SS去除率可达80％以上。     

化学生物絮凝与化学絮凝工艺处理城市污水--加药量对污染物去除效果的影响

化学生物絮凝工艺是利用将化学和生物协同絮凝作用处理污水的强化一级新工艺.试验通过在不同加药量情况下化学生物絮凝和化学絮凝工艺的中试试验对比研究,得出在相同加药量条件下,化学生物絮凝污染物去除效率均优于化学絮凝工艺10%～20%.在70 mg/L液体聚合氯化铝铁复配0.5 mg/L PAM的加药条件下,化学生物絮凝工艺经过30 min的水力停留时间,在进水CODCr为100～260 mg/L,TP为2～4 mg/L,SS为80～150 mg/L,NH3-N为10～25 mg/L条件下,出水CODCr、TP、SS、NH3-N满足城镇污水处理厂污染物排放二级标准.     

中置曝气生物活性炭工艺中的微絮凝

利用新型炭滤-砂滤工艺对南方湿热地区微污染源水进行中试规模的微絮凝实验研究。结果表明,接触絮凝时间为2~5 min时,投加1.0 mg/L的PAC微絮凝效果最好。运行稳定后,砂滤器出水浊度≤0.1 NTU,对COD Mn的去除效果有一定改善,微型水生生物的种类和数量也较炭滤器有大幅度下降,其中双层砂滤的效果优于单层粗砂,但其水头损失增长较快。通过微絮凝,砂滤器对炭滤器反冲洗后初滤水能有较好处理效果,可有效简化运行工艺。同时可保证滤后水中铝含量满足《生活饮用水卫生标准》的要求。     

化学-生物絮凝工艺类神经网络模型比较研究

在化学-生物絮凝工艺中试研究的基础上,分别建立了基于BP类神经网络的多输入多输出（MIMO）模型与多输入单输出（MISO）模型。应用化学生物絮凝工艺中试6个不同工况的实测数据对2个模型进行训练,均表现出很好的收敛性。通过另外2个中试工况的实测数据对模型预测性能进行测试,MISO模型对化学-生物絮凝反应器出水的COD、TP和SS的预测相对误差均低于MIMO模型,其预测相对误差均在9%以下。研究表明,MISO模型是一个很易使用的建模工具,能很好地预测化学-生物絮凝工艺出水水质。     

电解絮凝-生物炭滤池法处理印染废水

采用电解絮凝 -生物炭滤池串联工艺对印染废水进行处理研究。实验结果表明 ,控制电解在 2 8A m2 的电流密度和 2 0min的停留时间下运行 ,而调节生物炭滤池接触反应时间在 15 0min ,处理后的出水CODCr、BOD5及色度等指标能达到纺织染整工业废水的I级排放标准。同时 ,该工艺具有很好的除磷效果     

高絮凝性微生物育种生物技术研究与应用进展

本文从微生物絮凝性遗传学，絮凝基因分子克隆，絮凝菌种资源开发，微生物絮凝剂的研制与絮凝剂的研制与絮凝污染物的优势等方面进行了综述报导，同时对絮凝性微生物产生絮凝性的有关机理和条牛进行了讨论。     

白龙港水质净化厂污水化学-生物联合絮凝试验研究

为有效降低污水对长江人海口的污染,针对白龙港水质净化厂的水质状况,采用化学-生物联合絮凝工艺,对污水处理效果进行了研究,结果表明,与单独生物絮凝吸附工艺相比,化学-生物联合絮凝吸附工艺可以承受更高的水力负荷,并可节省部分药剂消耗量和污泥处理成本.     

微生物絮凝剂L-3絮凝性能及废水处理研究

研究了影响微生物絮凝剂L 3絮凝活性的因素 ,并考察了其在染料废水处理方面的应用前景。结果表明 ,该絮凝剂絮凝膨润土悬浮液的最适宜pH值为 8,Ca2 + 、Mg2 + 等阳离子对其絮凝具有促进作用 ,对酸性湖兰A、碱性品红、活性翠绿KN R和直接深紫NM具有较好的脱色性能 ,脱色率分别达到 93%、84 2 %、75 5 %和 86 %。对赣州毛纺厂印染废水的处理结果为 :脱色率达 94 0 % ,COD去除率为 70 8%。     

不同泥龄对活性污泥絮凝特性的影响

为了揭示不同污泥龄活性污泥的絮凝特性及作用机制,采用序批式反应器,考察污泥龄（solid retention time,SRT）对絮体EPS（extra-micro colony polymeric substances,EMPS）和菌胶团EPS（extra-cellular polymeric substances,ECPS）2种EPS组分的影响,通过扩展的DLVO理论和EPS组分解析不同污泥龄的絮凝性能。研究结果表明,随着SRT的增大,活性污泥的相互作用能曲线存在明显的势垒和势垒值逐渐减少,EMPS和ECPS含量逐渐减少,且相对于ECPS的变化,EMPS含量随泥龄的变化更加明显,其中蛋白质与腐殖质含量逐渐降低,污泥絮凝性能变好。这表明,较高的污泥相互作用能势垒和EMPS组分含量是污泥絮凝性能低的内在机制,且EMPS中蛋白质和腐殖质含量的变化是不同污泥龄污泥絮凝性能差异的主要原因。     

低碳排放的生物絮凝中试系统污染物去除特性及污泥EPS变化

用中试规模生物絮凝工艺处理含化学絮凝剂的生活污水,分别研究了HRT和进水SS对生物絮凝系统污染物去除特性、剩余污泥产量、污泥特性和温室气体排放的影响。结果表明：生物絮凝系统对COD、TN和TP有较好的去除效果,且污染物去除效果受进水SS影响较大;生物絮凝系统平均污泥产量和平均有机物产量最高可达 53.63 kg·d⁻¹和21.14 kg·d⁻¹;污泥胞外聚合物EPS浓度和PN/PS均与有机负荷呈反比;化学絮凝剂通过影响PN/PS和EPS浓度,可间接影响污泥的沉降性能;生物絮凝系统与AAO工艺相结合,可降低50.12 g·m⁻³温室气体的排放。因此,生物絮凝工艺可为污水处理厂节能降耗运行奠定基础,有望得到广泛应用。     

外源钙离子对好氧活性污泥反应器溶解性有机氮特征的影响

为探明外源钙离子对好氧活性污泥系统溶解性有机氮 (DON) 的影响,考察了不同钙离子浓度下 (0~1 mmol·L⁻¹) 出水DON浓度和生物有效性的变化,并结合傅里叶变换离子回旋共振质谱 (FTICR-MS) 及微生物代谢活性和群落结构分析探究钙离子影响的分子层面原因和微生物内在机理。结果表明,出水DON的浓度和生物有效性随着外源钙离子浓度的增加均呈现阈值现象,在最佳钙离子投加阈值浓度 (0.1 mmol·L⁻¹ Ca²⁺) 下,出水DON浓度和生物有效性为1.46±0.12 mg·L⁻¹和17.97%±0.05%,比空白组 (0 mmol·L⁻¹ Ca²⁺) 分别增加了35.2%和降低了47.6%。FTICR-MS分析DON的分子特征显示,钙离子是通过影响好氧活性污泥反应器中氧化程度较低分的组分 (NOSC<0) 影响了最终出水DON的生物有效性。微生物学分析表明,三磷酸腺苷、琥珀酸脱氢酶、脱氢酶、饱和脂肪酸和Luteolibacter菌是推动出水DON去除率提升和生物有效性降低的重要因素。     

Accumulation and fraction distribution of Ni(II) in activated sludge treating Ni-laden wastewater

The accumulation and fraction distribution of Ni(II) in sludge was determined, and their effect on the performance of sequencing batch reactor (SBR) systems was evaluated at laboratory scale. The results showed that the removal efficiencies of substrates decreased significantly with increasing feeding concentration of Ni(II) into SBRs. The concentration of Ni(II) fed into the SBRs was significantly positively correlated with the Ni(II) contents accumulated in the sludge, while it was negatively correlated with the biomass in the SBRs. The accumulated Ni(II) in the sludge was distributed mainly in the available fraction, accounting for 75.8–90.0 % of the total Ni(II) content. The accumulated content of Ni(II) in each sludge fraction could be predicted satisfactorily by the feeding Ni(II) concentrations in the solutions. As compared with the total contents and other chemical fractions, Ni(II) in the oxidizable fraction in sludge exhibited more important inhibition effects on sludge microorganisms in the SBRs.     

Effects of nano-copper(II) oxide and nanomagnesium oxide particles on activated sludge

Effects of nano-copper(II) oxide (nano-CuO) and nanomagnesium oxide (nano-MgO) particles on activated sludge endogenous respiration (aerobic digestion), biochemical oxygen demand (BOD) biodegradation, and nitrification were investigated through respiration rate measurement. For comparison, the effects of Cu(II) and Mg(II) ions on activated sludge were also studied. Results indicated that soluble Cu(II) has half maximum inhibitory concentration (IC50) values of 19, 5.5, 53, and 117 mg Cu/L for endogenous respiration, BOD biodegradation, ammonium oxidation, and nitrite oxidation, respectively. However, nano-CuO only inhibited BOD biodegradation at 240 mg Cu/L or more, and its associated toxicity was primarily caused by soluble Cu(II). In contrast, soluble Mg(II) was not toxic to activated sludge in the experimental concentration range, but nano-MgO inhibited BOD biodegradation and nitrification with IC50 values of 70 and 143 mg Mg/L, respectively. Further study indicated that the toxicity of nano-MgO resulted primarily from increased pH following MgO hydrolysis.     

重金属离子对活性污泥处理污水的影响

研究了Hg2+、Cd2+、Pb2+3种金属离子对活性污泥系统处理污水效能的影响。通过对出水理化指标和生物指标的测定反映Hg2+、Cd2+、Pb2+对活性污泥系统运转效能的影响。结果表明:实验第4 d,Hg2+(0.3、0.4、0.5和0.6 mg/L),Cd2+(15、20、25和30 mg/L)和Pb2+(300、400、600和800 mg/L)各实验组出水的COD、SVI等均有显著影响。在实验中得出,对COD影响最为明显的为浓度600 mg/L和800 mg/L Pb2+实验组,在第4 d时,出水的COD去除率已经为零。锐利楯纤虫对Hg2+的浓度变化耐受力较强;点钟虫对Cd2+的浓度变化耐受力较强;杯钟虫对Cd2+的浓度变化耐受力较强。锐利楯纤虫对Pb2+和Cd2+的浓度变化较为敏感;点钟虫对Hg2+的浓度变化较为敏感;小口钟虫对Pb2+的浓度变化较为敏感。     

Investigation of Cr(VI) reduction in continuous-flow activated sludge systems

The aim of this research was to investigate hexavalent chromium, Cr(VI), reduction by activated sludge and to evaluate the use of continuous-flow activated sludge systems for the treatment of Cr(VI)-containing wastewater. Three series of experiments were conducted using two parallel lab-scale activated sludge systems. During the first experiment, one system was used as a control, while the other received Cr(VI) concentrations equal to 0.5, 1, 3 and 5mg l(-1). For all concentrations added, approximately 40% of the added Cr(VI) was removed during the activated sludge process. Determination of chromium species in the dissolved and particulate phase revealed that the removed Cr(VI) was sorbed by the activated sludge flocs mainly as trivalent chromium, Cr(III), while the residual chromium in the dissolved phase was mainly detected as Cr(VI). Activated sludge ability to reduce Cr(VI) was independent of the acclimatization of biomass to Cr(VI) and it was not affected by the toxic effect of Cr(VI) on autotrophic and heterotrophic microorganisms. During the second experiment, both systems were operated under two different hydraulic residence time (theta equal to 20 and 28h) and three different initial organic substrate concentration (COD equal to 300, 150 and 0mg l(-1)). Cr(VI) reduction was favored by an increase of theta, while it was limited by influent COD concentration. Finally, at the last experiment the effect of anoxic and anaerobic reactors on Cr(VI) reduction was investigated. It was observed that the use of an anoxic zone or an anaerobic-anoxic zone ahead of the aerobic reactor favored Cr(VI) reduction, increasing mean percentage Cr(VI) reduction to almost 80%.     

Improved computational model (AQUIFAS) for activated sludge, integrated fixed-film activated sludge, and moving-bed biofilm reactor systems, part II: multilayer biofilm diffusional model

Research was undertaken to develop a diffusional model of the biofilm that can be applied in lieu of a semi-empirical model to upgrade an activated sludge system to an integrated fixed-film activated sludge (IFAS) or moving-bed biofilm reactor (MBBR) system. The model has been developed to operate with up to 12 cells (reactors) in series, with biofilm media incorporated to one or more of the zone cells, except the anaerobic zone cells. The values of the kinetic parameters for the model were measured using pilot-scale activated sludge, IFAS, and MBBR systems. The biofilm is divided into 12 layers and has a stagnant liquid layer. Diffusion and substrate utilization are calculated for each layer. The equations are solved simultaneously using a finite difference technique. The biofilm flux model is then linked to the activated sludge model. Advanced features include the ability to compute the biofilm thickness and the effect of biofilm thickness on performance. The biofilm diffusional model is also used to provide information and create a table of biofilm yields at different substrate concentrations that can be used in the semi-empirical model.     

多生境膜生物反应器中活性污泥的流变特性

以多生境膜生物反应器运行过程中活性污泥的流变性能为研究对象,考察污泥浓度（MLSS）和剪切速率（γ）对活性污泥流变特性的影响,以期揭示其中活性污泥的流变学特性,从而为优化其运行提供理论及实验基础。反应器系统在不排泥的情况下运行,持续运行105 d,反应器内生物质浓度从刚开始驯化的3 200 mg·L-1累积到最终的12 500 mg·L-1。在运行过程中,在常温下同步测定了污泥的动力黏度、极限黏度和上清液黏度。结果表明：随着剪切速率的增大,污泥黏度均减小,表现出剪切稀化的特性,非牛顿流体的特征十分明显;活性污泥极限黏度随MLSS、EPS增加而增大,在低质量浓度（-1）下的活性污泥流变特性与Bingham模型十分吻合,而在高质量浓度（>8 000 mg·L-1）下的则近似于Ostwald de Vaele模型。