双膜曝气生物膜反应器除水中硝氮和高氯酸盐

构建了一种以CO₂为唯一碳源的膜曝气氢基质生物膜反应器（H₂-MBfR）对模拟地下水中2种主要的氧化型无机无污染物（NO₃^--N和ClO₄^-）进行生物还原去除.通过膜曝气方式使CO₂起到提供碳源和调节反硝化过程中pH值跃升的双重作用,克服了传统方法所带来的二次污染和运行成本增加的问题.通过调整H₂和CO₂压力能够实现对反应器出水pH值的较为稳定的控制,当CO₂压力分别为0.05MPa和0.08MPa 2个阶段时,在平均NO₃^--N和ClO₄^-进水浓度分别为20.73mg/L和10.57mg/L条件下,两阶段出水平均pH值分别为8.45和8.06,NO₃^--N和ClO₄^-去除率均大于95%;当第3阶段CO₂压力提升至0.12MPa时,平均出水pH值下降至6.93,此时NO₃^--N和ClO₄^-去除通量明显降低.而提供过量的CO₂会导致在偏酸性条件下甲烷化过程的产生,从而会导致其对H₂的负面消耗进而使目标污染物的还原速率下降.因此,合理控制CO₂压力使反应体系pH值维持在中性偏碱性条件下有利于NO₃^--N和ClO₄^-还原过程的高效进行.     

非灭菌条件下白腐真菌在反应器中的形态特征变化

揭示白腐真菌(Phanerochaete chrysosporium)在反应器中的形态变化有助于了解白腐真菌反应器难以连续运行问题的本质. 在耦合臭氧单元的反应器对酸性蓝45连续降解的过程中,考察了非固定化和固定化菌丝系统中白腐真菌的形态特性变化. 结果表明,在接种量为1 700 mg/L的非固定化系统中,染菌量为7.1×105 CFU/mL,平均脱色率为19%;但菌丝球形态不稳定,运行8~12 d时出现破裂、菌丝脱落、内容物大量流失,污染微生物的生长加剧. 在固定化系统中,接种量为1 700 mg/L时,染菌量降至8.4×104 CFU/mL,平均脱色率升至22%;接种量为4 300 mg/L时,染菌量降至4.7×104 CFU/mL,平均脱色率达29%. 在固定化菌丝系统中,白腐真菌的形态相对稳定,但21 d后,其稳定性降低,也出现了菌丝脱落现象,这与菌丝球或固定化菌丝的内部菌丝老化和自溶有关,可以考虑通过设计新载体从生物膜的内部和外部同时供给营养物和氧气解决该问题.      

Analysis of floc morphology in a continuous-flow flocculation and sedimentation reactor

The floc morphology was investigated in a continuous-flow reactor, in order to understand the evolution of flocs in practical flocculation and sedimentation processes in water utilities. Kaolin-humic acid suspension was used as the test water, and polyaluminum chloride was chosen as the coagulant. An in-situ recognition system was applied to analyze the floc size, boundary fractal dimension, and eccentricity ratios. Particle numbers and turbidity were also determined in the sedimentation stage. At a coagulant dose of 1 mg/L as Al, the average floc size increased from 62 to 78 μm and the boundary fractal dimension was around 1.14, suggesting that flocs were compact and continuously grew during the entire flocculation process. However, with the dose increased to 5 mg/L, the average floc size decreased and stabilized at around 65 μm, with the fractal dimension of 1.20. It can be concluded that the excess coagulant doses resulted in the formation of chain-shaped, lower density, and more branched structure flocs, thereby restricting flocs' further growth in the subsequent flocculation. Floc morphology analysis suggested that charge neutralization dominated in the initial flocculation stage, then the bridge and sweep mechanisms were dominant in the subsequent flocculation. In addition, compared with the traditional inclined plate settler, a novel V-shaped plate settler introduced in this study had an advantage in small size floc(less than 5 μm) removal. The V-shaped region could promote aggregate restructuring and re-flocculation; therefore, the V-shaped plate settler provides an alternative method for sedimentation.     

低温供热堆选址阶段的环境影响评价与分析

根据低温供热堆选址阶段环境影响评价的要求,结合工程具体设计方案,对低温供热堆在正常运行和事故工况下可能造成的环境影响进行分析、预测与评价,以作为审管当局决策的重要依据.低温供热堆在正常运行状态时,放射性气载流出物在大气中迁移和扩散及对公众的辐射剂量估算采用的是IAEA安全系列19号报告中给出的筛选模式(稀释模式);事故...     

活性炭／沸石投加型活性污泥工艺的研究进展

在污水生物处理工艺中,向传统悬浮生长系统投加微生物载体所形成的复合式生长系统被称为复合式生物反应器。粉末活性炭与沸石是两种应用较为广泛的载体材料。在活性污泥系统中投加粉末活性炭与沸石,可提高其有机负荷,增强脱氮能力,改善污泥的沉降和脱水性能。简述投加粉末活性炭与沸石的复合式生物反应器的工艺流程、特点、作用机理和应用等,提出复合式生物反应器在应用中存在的主要问题,并对两种复合式生物反应器的研究方向进行了展望。     

Neural-fuzzy control system application for monitoring process response and control of anaerobic hybrid reactor in wastewater treatment and biogas production

Based on the developed neural-fuzzy control system for anaerobic hybrid reactor (AHR) in wastewater treatment and biogas production, the neural network with backpropagation algorithm for prediction of the variables pH, alkalinity (Alk) and total volatile acids (TVA) at present day time t was used as input data for the fuzzy logic to calculate the influent feed flow rate that was applied to control and monitor the process response at di erent operations in the initial, overload influent feeding and the recovery phases. In all three phases, this neural-fuzzy control system showed great potential to control AHR in high stability and performance and quick response. Although in the overloading operation phase II with two fold calculating influent flow rate together with a two fold organic loading rate (OLR), this control system had rapid response and was sensitive to the intended overload. When the influent feeding rate was followed by the calculation of control system in the initial operation phase I and the recovery operation phase III, it was found that the neural-fuzzy control system application was capable of controlling the AHR in a good manner with the pH close to 7, TVA/Alk < 0.4 and COD removal > 80% with biogas and methane yields at 0.45 and 0.30 m3/kg COD removed.     

医院污水处理中可吸附有机卤化物(AOX)及其毒性研究

对序批式膜生物反应器（MBR）处理前后医院污水中的AOX进行了比较,分析了c_Rt值对不同水质中AOX生成量的影响及相应的生物毒性.结果表明,序批式MBR对医院污水中AOX的去除率达到63.6％,其中膜截留占14.5％;要获得相同的c_Rt值,原污水所需的投氯量显著高于MBR出水,相应生成的AOX浓度也较高;通过曲线拟合发现,随着c_Rt的增长,医院原污水中AOX浓度呈指数增长,而MBR出水呈线性关系.以粪大肠杆菌为指示微生物,要达到医院污水微生物排放标准（GB 18466-2005）,医院原污水所需c_Rt为5.5 (mg·h)/L,而MBR出水只需c_Rt为0.007 5 (mg·h)/L,其相应的生物毒性分别为40.39 μg/L和8.96 μg/L (以K₂Cr₂O₇计),AOX浓度分别为607.1 μg/L和102.5 μg/L.     

几种新型光催化水质净化反应器的探讨

综述了几种新型光催化反应器的结构、特征，讨论各反应器的应用情况和处理效果，对其优缺点进行评价。指出光催化技术与其它成熟水处理技术的耦合是光催化工艺进入实际应用的重要途径。     

混凝土生态膜挂膜实验研究

将水泥、碎石、粉煤灰及活性材料CRLT-1等制作的透水混凝土生态膜在渠式反应器中进行挂膜实验,通过实验对2种挂膜方法进行了比较,对2种挂膜方法下填料上的生物量和生物活性及反应器对COD和NH3-N等指标的去除情况进行了测定和分析。结果表明,逐渐增加进水流量的循环挂膜法可以加快反应器启动,10d后COD的去除率稳定在69%左右,启动时间少于直接采用设计流量进水的循环挂膜法,2种情况下生物活性在4.19～4.85mgO2/g·h之间。     

Community analysis of ammonia and nitrite oxidizers in start-up of aerobic granular sludge reactor

A lab-scale sequencing batch reactor (SBR) was setup and the aerobic granular sludge was successfully incubated by using anaerobic granular sludge as seed sludge. Nitrogen was partially removed by simultaneous nitrification and denitrification (SND) via nitrite with free ammonia (FA) of about 10 mg/L. The denaturing gradient gel electrophoresis (DGGE) method was used to investigate community structure of α-Proteobacteria, β-Proteobacteria, ammonia oxidizing bacteria (AOB), and Nitrospira populations during start-up. The population sizes of bacteria, AOB and Nitrospira were examined using real-time PCR method. The analysis of community structure and Shannon index showed that stable structure of AOB population was obtained at the day 35, while the communities of α-Proteobacteria, β-Proteobacteria, and Nitrospira became stable after day 45. At stable stage, the average cell densities were 1.1×1012, 2.2×1010 and 1.0×1010 cells/L for bacteria, AOB and Nitrospira, respectively. The relationship between characteristics of nitrifying bacteria community and nitrogenous substrate utilization constant was discussed by calculating Pearson correlation. Certain correlation seemed to exist between population size, biodiversity, and degradation constant. And the influence of population size might be greater than that of biodiversity.