颗粒化序列间歇式活性污泥反应器工艺处理化粪池污水

在序列间歇式活性污泥反应器(SBR)中成功培养出适应化粪池污水水质的好氧颗粒污泥.并将其应用于化粪池污水的处理.在好氧颗粒污泥培养的第15天左右,SBR中开始出现细小的颗粒,然后微生物在其上繁殖生长使颗粒逐渐增大而成熟;在第24天时,SBR中絮状活性污泥已基本实现了颗粒化.培养出的好氧颗粒污泥对化粪池污水有稳定的处理效果,在进水完全为化粪池污水时,COD、NH_4~+-N、TN的平均去除率分别为77%、61%、47%.但是,由于化粪池污水COD较低,因此无法维持较高的生物量,在后期的稳定运行过程中MLSS始终维持在2 500 mg/L左右.好氧颗粒污泥的同步硝化反硝化作用是其稳定脱氮的保证.     

化粪池技术在分散污水治理中的应用与发展

化粪池技术简单易行,运行维护要求低,在分散污水处理中有着历史悠久和广泛的应用。介绍了化粪池的产生背景和作用机理,指出了当前传统化粪池在分散污水处理中出现的问题,总结了国内外对化粪池技术的改进和应用,展望了化粪池技术未来应用趋势。提出建议：在常规卫生模式下的乡村分散污水治理中,如规划采用传统化粪池/自然处理系统时,应加强化粪池的设计、安装与运行的管理,使其发挥应有的作用;如规划采用构造型分散污水处理系统时,可取消传统化粪池的设置;如对氮磷没有控制要求,则可以考虑采用强化型的化粪池技术。在构建面向资源化的乡村分散卫生系统中,应着重开发基于粪便收集利用的高效、安全且运行维护简便的就地化粪池技术。     

漂浮植物塘协同处理农村分散生活污水研究

通过实验考察了漂浮植物塘对经模拟化粪池简易处理的农村分散生活污水的深度净化效果,结果表明：水葫芦、大薸、聚草塘对上述污水均具有良好的净化效果,水葫芦塘对TP的去除效果最好,大薸塘对TN和NH⁺₄-N的去除效果最好。当水力停留时间为20 d时,3种漂浮植物塘的出水污染物含量可低于GB/T 18921-2002观赏性景观环境用水河道类标准。在南方农村宅沟园河内种植漂浮植物是构建农村实用生活污水收集处理系统、控制农村生活污水对河道污染的一种有效措施。     

Treatment of Arctic wastewater by chemical coagulation,UV and peracetic acid disinfection

Conventional wastewater treatment is challenging in the Arctic region due to the cold climate and scattered population. Thus, no wastewater treatment plant exists in Greenland, and raw wastewater is discharged directly to nearby waterbodies without treatment. We investigated the efficiency of physicochemical wastewater treatment, in Kangerlussuaq, Greenland. Raw wastewater from Kangerlussuaq was treated by chemical coagulation and UV disinfection. By applying 7.5 mg Al/L polyaluminium chloride (PAX XL100), 73% of turbidity and 28% phosphate was removed from raw wastewater. E. coli and Enterococcus were removed by 4 and 2.5 log, respectively, when UV irradiation of 0.70 kWh/m³ was applied to coagulated wastewater. Furthermore, coagulated raw wastewater in Denmark, which has a chemical quality similar to Greenlandic wastewater, was disinfected by peracetic acid or UV irradiation. Removal of heterotrophic bacteria by applying 6 and 12 mg/L peracetic acid was 2.8 and 3.1 log, respectively. Similarly, removal of heterotrophic bacteria by applying 0.21 and 2.10 kWh/m³ for UV irradiation was 2.1 and greater than 4 log, respectively. Physicochemical treatment of raw wastewater followed by UV irradiation and/or peracetic acid disinfection showed the potential for treatment of arctic wastewater.     

Disinfection of an advanced primary effluent with peracetic acid and ultraviolet combined treatment: a continuous-flow pilot plant study

Disinfection of an advanced primary effluent using a continuous-flow combined peracetic acid/ultraviolet (PAA/UV) radiation system was evaluated. The purpose was to determine whether the maximum microbial content, established under Mexican standards for treated wastewaters meant for reuse--less than 240 most probable number fecal coliforms (FC)/100 mL--could be feasibly accomplished using either disinfectant individually, or the combined PAA/UV system. This meant achieving reduction of up to 5 logs, considering initial concentrations of 6.4 x 10(+6) to 5.8 x 10(+7) colony forming units/100 mL. During the tests performed under these experiments, total coliforms (TC) were counted because FC, at the most, will be equal to TC. Peracetic acid disinfection achieved less than 1.5 logs TC reduction when the C(t) x t product was less than 2.26 mg x minimum (min)/L; 3.8 logs for C(t) x t 4.40 mg x min/L; and 5.9 logs for C(t) x t 24.2 mg x min/L. In continuous-flow UV irradiation tests, at a low-operating flow (21 L/min; conditions which produced an average UV fluence of 13.0 mJ/cm2), the highest TC reduction was close to 2.5 logs. The only condition that produced a disinfection efficiency of approximately 5 logs, when both disinfection agents were used together, was the combined process dosing 30 mg PAA/L at a pilot plant flow of 21 L/min and contact time of 10 minutes to attain an average C(t) x t product of 24.2 mg x min/L and an average UV fluence of 13 mJ/cm2. There was no conclusive evidence of a synergistic effect when both disinfectants were employed in combination as compared to the individual effects achieved when used separately, but this does not take into account the nonlinearity (tailing-off) of the dose-response curve.     

微波-过氧乙酸联合作用处理剩余污泥的研究

采用微波-过氧乙酸(PAA)联合作用处理剩余污泥,考察了微波辐照时间、微波功率、PAA投加量对剩余污泥分解效果的影响.同时以单独微波作用为对比,考察了微波-PAA联合作用下剩余污泥性质的变化.结果表明,当微波功率为600 W,PAA投加量为0.24 g/g(以干质量SS计)时,微波辐照60 s后剩余污泥分解率可达35%...     

我国农村化粪池污染物去除效果及影响因素分析

探究农村化粪池污染物去除效果及主要影响因素对于理解我国农村化粪池粪污处理现状十分必要.本研究基于山西、陕西、浙江、湖南、广东和重庆6个选点区域57家农户化粪池的监测结果,分析了农村化粪池处理污染物的现状和主要影响因素.结果表明,区域化粪池对化学需氧量(COD)、5日生化需氧量(BOD5)、氨氮(NH3-N)、总氮(TN...     

改进型农村三格化粪池的污水处理性能

在我国农村地区,化粪池仍然是许多家庭生活污水直排前的唯一处理设施。传统三格化粪池出水水质较差,造成了农村水环境污染,而对传统三格化粪池进行适当改进是解决污染问题的有效途径之一。为此,对传统三格化粪池进行了结构和功能的优化设计,在第1格设置由过流板隔开的预处理曝气池和预处理沉淀池,第2格保留厌氧发酵池,第3格由过流板分隔为生物接触氧化池和二次沉淀池。结果表明,稳定运行后,反应器对COD、${\rm{NH}}_4^ + $-N、TP和SS的去除率分别为83.51%~88.56%、66.82%~74.17%、77.47%~81.12%和82.26%~88.57%,相较于传统三格化粪池有显著的提升。改进型农村三格化粪池实现了农村分散式污水的就地处理,且经济性和维护便利性符合农村污水处理设施的定位需求,可为农村三格化粪池的改造和新建提供参考。     

Disinfection and dewatering of wastewater solids by interstitial vapor generation.

Disinfection of wastewater solids (waste activated solids [WAS]) by interstitial vapor generation was investigated. In addition to the magnitude of disinfection, the amount of water removed and cost relative to traditional residuals disinfection processes was also examined. The process of interstitial vapor generation occurs as a result of the rapid heating of liquid in the interstices of the solid-liquid array. Intense heating causes boiling of the slurry liquid, resulting in an expanding vapor front that simultaneously dewaters the wastewater solids and contributes to the destruction of viable pathogenic microorganisms. Objectives of the study were threefold: (1) to validate disinfection of WAS using the interstitial vapor technique; (2) establish the degree of possible drying of the residuals using the techniques; and (3) establish the key operating variables for the process. Results showed a significant reduction in the most probable number of total coliforms and Escherichia coli (E. coli). Specifically, greater than four-log unit reductions were produced for both total coliform and E. coli bacteria. In addition to quantifying the reduction in bacteria, the percent solids were increased from an initial amount of 7.6% (mass basis) to a final solids content greater than 90% using optimal processing conditions. Cost comparisons were also conducted and shown to be quite favorable when compared with traditional disinfection methods such as lime addition. Because of the high level of E. coli reduction achieved, the process of interstitial vapor generation is shown to be capable of converting a class B biosolids into a class A pathogen reduced product. For example, an initial most probable number (MPN) of 1.2 x 10(6) E. coli bacteria were reduced to 19 at the extreme conditions of the process, well below the requirement of an MPN of 1000 for fecal coliform bacteria. Given its ability to disinfect and dewater wastewater solids, the interstitial vapor generation process was found to be a robust and beneficial technique to produce an environmental and publicly acceptable recyclable biosolids resource.     

紫外/过氧乙酸灭活大肠杆菌的效能及机理

病原微生物对公共卫生及生态系统产生了极大威胁,为研究紫外/过氧乙酸体系(UV/PAA)的消毒效能,以大肠杆菌为目标微生物,考察了PAA和UV投加剂量、不同背景物质对大肠杆菌灭活的影响,检测了体系中生成的活性物种并观察了反应过程中细胞形态变化。结果表明：在PAA浓度为60 μmol·L⁻¹和UV光强为2.25×10⁻⁷ Einstein·(s·L)⁻¹的条件下反应3 min后,大肠杆菌的灭活率能达到4.71 log,相较单独PAA体系和单独UV体系分别提高了2.76 log和0.82 log,且灭活率随PAA浓度和UV辐射剂量增加而提高。NH₄⁺和Cl⁻对于UV/PAA体系灭活大肠杆菌有轻微的抑制作用,而腐殖酸(HA)对于体系有较强的抑制作用。自由基淬灭实验和电子顺磁共振检测结果表明,UV/PAA体系灭活大肠杆菌的主要活性物质为羟基自由基(HO·)和有机自由基(RO·)。激光共聚焦显微镜和扫描电子显微镜观察的结果表明,UV/PAA体系灭活大肠杆菌时,会引起细胞膜轻微破损,但并不会导致严重的裂解。反应溶液中溶解性成分的荧光光谱分析表明大肠杆菌灭活时释放的有机物会随着细胞膜破损而增加,但释放的类蛋白大分子物质最终可被氧化为类腐殖酸小分子有机物。     

有效微生物和多功能复合微生物制剂生物强化提高化粪池粪便污泥减量效率研究

为了考察有效微生物(EM)和多功能复合微生物制剂(MCMP)对化粪池粪便污泥减量的强化效能,以化粪池粪便污泥为研究对象,采用中温(35℃)厌氧消化,研究EM和MCMP不同投加量(0~1.00%)对化粪池粪便污泥厌氧消化总固体(TS)、挥发性固体(VS)和COD的减量效果,考察EM和MCMP投加量与TS、VS和COD去除率间的相关关系。结果表明,投加0.005%~0.10%的EM和MCMP均有利于化粪池粪便污泥TS、VS和COD的去除;其中以投加0.01%的EM(E2处理)和0.01%的MCMP(M2处理)对TS、VS和COD的去除效果最好。E2处理TS、VS和COD的去除率分别为32.51%、42.34%和40.91%,分别比对照(CK)高5.83%、5.29%和7.13%;M2处理TS、VS和COD的去除率分别为33.74%、46.05%和43.33%;分别比CK高7.06%、9%和9.50%。对化粪池粪便污泥厌氧消化TS、VS和COD的减量作用效果表现为:MCMPEM。EM和MCMP的投加量与TS、VS和COD去除率间均存在一定的负相关关系;投加EM和MCMP的各处理的TS、VS和COD去除率两两间均表现为正相关关系。     

曝气浸没固定生物膜反应器处理化粪池出水

研究了以丝瓜络作为生物膜载体的曝气浸没固定生物膜反应器在处理化粪池出水时的可行性以及运行性能。结果表明,丝瓜络生物膜反应器可以在2周内成功启动;水力停留时间(HRT)对COD和氨氮的去除效果有显著影响,在水力停留时间为4 h的条件下,系统对COD和氨氮的去除率分别达到了78.5%和96.4%。另外,系统有较强抗有机污染物冲击负荷的能力,当COD和氨氮的进水浓度分别为59.3 mg/L和15.9 mg/L时,系统对有机污染物的去除效果较佳,去除率分别达到了80.0%和98.9%。     

混凝沉淀-厌氧折流板反应池-两级好氧生化工艺处理毛毯废水

采用混凝沉淀 厌氧折流板反应池 两级好氧生化工艺处理毛毯废水。在废水 pH为 4 .6 3— 6 .95、CODCr为96 6— 1990mg/L、BOD5为 2 4 3— 4 97mg/L、SS为 344— 4 36mg/L、色度 4 0 0倍时 ,处理出水达到一级排放标准。该处理技术先进、可靠。     

Chemical modification of montan resin by peracetic acid and agricultural application of its modified products

ABSTRACT

Montan resin (MR) is a by-product produced during the refinement process of montan wax extracted from lignite and has no usage yet. Chemical modification is an effective method to change the material property for expanding or converting the application area of the material itself. Our previous study found that the high hydrophobicity of MR is the primary limiting factor for its utilization in agriculture. Based on this point, this study attempted to chemically modify MR using the oxidation of peracetic acid, resulting that the MR hydrophilicity was significantly improved, and a water-soluble product (WSP) was obtained. The optimized oxidation conditions of MR, including the reaction temperature (X₁), reaction time (X₂), weight ratio of oxidant and montan resin (X₃), and oxidant concentration (X₄), were determined using single-factor experiments and response surface analysis. The modification degree was evaluated using elemental and oil-water partition coefficient analyses, infrared (IR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS), revealing that the oil-water partition coefficient of the modified product decreased and that the number of chemical constituents with oxygen-containing functional groups clearly increased after modification. Furthermore, the WSP was tested its effects on germination and seedling growth of the wheat seed. Compared with the control group, the WSP showed a promoting effect on the growth and germination of wheat. The WSP concentrations of 600 mg·L^?1 and 300 mg·L^?1 had the most substantial effect on the root and seedling growth of wheat, respectively.

Implications: Montan resin, a useless by-product produced from crude montan wax, was chemically modified via oxidation of peracetic acid. Its hydrophilicity was significantly improved, and a water-soluble product was obtained after the chemical modification. The optimized oxidation conditions of montan resin were determined using single-factor experiments and response surface analysis. The amount of chemical constituents with oxygen-containing functional groups increased in the modified products after modification, as determined by IR and GC-MS analysis, among other methods. The water-soluble modified product showed an obvious effect in promoting growth and germination of wheat at 600 mg·L-1 and 300 mg·L-1, respectively.     

规模化城市污水处理厂沉淀池模拟优化

高效沉淀池广泛应用于市政污水处理厂,其表面负荷是沉淀效率的关键指标。为将实际工程表面负荷稳定提升到12 m·h⁻¹,采用计算流体力学方法,模拟优化了高效沉淀池的负荷。结果表明,污泥特性和几何构型的协同关系是提高沉淀池表面负荷的关键。宽下降区、长挡墙有利于提升流场的均匀性,但远端出水堰的污泥流失风险限制了表面负荷提升。优化的挡墙长度、上升区/下降区(1/2.65)之比等几何构型特征,能够减少积泥斗污泥扰动,改善总体流场均匀性,从而将表面负荷提高到11~12 m·h⁻¹。污泥沉淀过程中的流变特性和流动本构认识不足,限制了表面负荷的进一步提升。上述结果提升了高效沉淀池工程负荷,深化了对高效沉淀池流态的认识,亦为污水处理系统的减污降碳协同增效提供运行优化工具及案例参考。     

城市污水处理厂二沉池出水曝气混合絮凝的研究

在污水处理厂实验室,对二沉池出口污水进行了曝气和机械2种方式的混合絮凝对比试验。研究结果表明,对于同一水质,在相同的投药量下,曝气混凝沉淀后的水质明显优于机械混凝沉淀后的水质,各项水质指标的去除率分别提高：BOD₅ 6%～9%,COD 4%～6%,NH₃-N 6%～9%,TP 15%～24%,SS 8%～18%。     

Wastewater disinfection alternatives: chlorine, ozone, peracetic acid, and UV light.

Disinfection tests were carried out at pilot scale to compare the disinfection efficiency of ozone, sodium hypochlorite (NaOCl), peracetic acid (PAA), and UV irradiation. Total coliforms, fecal coliforms, and Escherichia coli were monitored as reference microorganisms. Total heterotrophic bacteria (THB) were also enumerated by cytometry. At similar doses, NaOCl was more effective than PAA, and its action was less affected by contact time. The results obtained by ozonation were comparable for total coliforms, fecal coliforms, and E. coli. On the contrary, some differences among the three indicators were observed for NaOCl, PAA, and UV. Differences increased with increasing values of the disinfectant concentration times contact time (C x t) and were probably the result of different initial counts, as total coliforms include fecal coliforms, which include E. coli. The UV irradiation lead to complete E. coli removals, even at low doses (10 to 20 mJ/cm2). Total heterotrophic bacteria appeared to be too wide a group to be a good disinfection indicator; no correlation was found among THB inactivation, dose, and contact time.     

Wastewater disinfection by peracetic acid: assessment of models for tracking residual measurements and inactivation.

With its potential for low (if any) disinfection byproduct formation and easy retrofit for chlorine contactors, peracetic acid (PAA) or use of PAA in combination with other disinfectant technologies may be an attractive alternative to chlorine-based disinfection. Examples of systems that might benefit from use of PAA are water reuse schemes or plants discharging to sensitive receiving water bodies. Though PAA is in use in numerous wastewater treatment plants in Europe, its chemical kinetics, microbial inactivation rates, and mode of action against microorganisms are not thoroughly understood. This paper presents results from experimental studies of PAA demand, PAA decay, and microbial inactivation, with a complementary modeling analysis. Model results are used to evaluate techniques for measurement of PAA concentration and to develop hypotheses regarding the mode of action of PAA in bacterial inactivation. Kinetic and microbial inactivation rate data were collected for typical wastewaters and may be useful for engineers in evaluating whether to convert from chlorine to PAA disinfection.     

Reduction of photoreactivation with the combined UV/peracetic acid process or by delayed exposure to visible light.

Photoreactivation of microorganisms following UV inactivation is a well-known, but complex, phenomenon. It is affected by several factors, including UV fluence, wavelength, light intensity, and exposure time to photoreactivating light. The effect on photoreactivation of a combined peracetic acid (PAA)/UV process has not been investigated. Accordingly, this study compared the degree of photoreactivation, under both sunlight and artificial lights, following UV and combined PAA/UV inactivation of fecal coliforms. Effluent samples from the Montreal Wastewater Treatment Plant (MWTP) (Quebec, Canada) were exposed, for 3 hours, to both low- and high-intensity artificial lights and sunlight. All resulted in similar photoreactivation levels. However, average photoreactivation for UV-treated wastewater samples was 1.2 logs, compared with 0.1 log for the combined PAA/UV treatment. Hence, the use of PAA in combination with UV can significantly reduce the potential for photoreactivation. To simulate the photoreactivation conditions of the MWTP effluent (which passes through a 4-km outfall tunnel with approximately 3 hours detention time), UV-treated samples were kept in the dark for 3 hours before photoreactivating light exposure. After this period, photoreactivation levels were close to zero. Hence, the effects of photoreactivation may be diminished by use of a combined disinfection scheme and/or by delaying exposure of the disinfected wastewater to light.