A~2/O氧化沟城镇污水处理厂的设计与运行

文章系统介绍了南方某城镇污水处理厂A2/O氧化沟的工艺设计。其设计总规模为1.2万m3/d,采用A2/O氧化沟工艺,污泥采用机械浓缩和脱水。运行一段时间后的结果表明:A2/O氧化沟工艺处理城镇污水出水水质稳定,可达到《城镇污水处理厂污染物排放标准》(GB18918—2002)中的一级B标准。     

A/O工艺处理煤气化高氨氮废水的应用与优化

采用A/O工艺处理煤气化、合成氨装置生产废水,对工艺运行参数进行优化调整,优化实施后,出水水质达到GB 8978—1996《污水综合排放标准》的一级标准。     

A/A/O工艺在城镇生活污水处理厂的应用

宜黄县污水处理厂原设计出水标准为《城镇污水处理厂污染物排放标准》(GB18918-2002)一级B标准,实际出水已无法满足当前国家及当地政府规划要求。因此政府要求新建污水处理厂,工程设计规模为2×10~4 m~3/d。该厂采用A/A/O生物处理作为二级处理主体工艺,深度处理采用高效沉淀池+纤维转盘滤池工艺。该厂正式运行2个多月以来,主要出水指标均达到一级A标准,单位经营成本为1.22元/m~3。     

城镇污水处理厂工艺设计及特点分析

广东省揭阳市区污水处理厂工程近期设计规模为6.0×104m3/d,采用A2/O处理工艺,设计出水水质执行GB 18918—2002《城镇污水处理厂污染物排放标准》中一级B标准。介绍了该工程的概况、工艺流程、主要构筑物及主要设计参数,总结分析了工艺设计的技术特点、运行效果及主要技术经济指标,工程运行结果表明,该工艺运行稳定,处理效果良好,适合在广东省地区推广应用。     

多级A/O工艺在污水处理厂提标升级改造中的应用

以成都市某净水厂提标升级改造工程为例，在投资及用地受限情况下，采用多级A/O+高密度沉淀池+反硝化滤池的主体工艺，改造完成后出水水质由《城镇污水处理厂污染物排放标准》（GB 18918-2002）一级A标准提升为《四川省岷江、沱江流域水污染物排放标准》DB 51/2311-2016。本项目中采用的多级A/O改造模式及设计参数对未来类似工程具有指导意义，为推广多级A/O工艺提供现实价值。     

A/O+BAF组合工艺处理石化废水现场应用

介绍采用A/O与BAF组合工艺对石化混合废水进行处理的情况。在污水厂A/O工艺基础上,加一级低负荷曝气生物滤池(BAF),并进行现场应用,考察A/O+BAF组合工艺对该类混合石化废水的处理效果。运行结果表明,该组合工艺运行成本低,出水满足GB 13457—1996《污水综合排放标准》一级排放标准要求。     

A/A/O+MBR工艺在污水厂站提标改造中的应用

北京某污水处理站为600 t/d设计水量，由于处理后外排水质不达标，设计将原CASS工艺改造为A/A/O+MBR工艺，改造处理后的出水水质为北京市《水污染物综合排放标准》(DB11/307—2013)规定的B排放限制标准。工程运行后出水达到北京市河道排放标准并恢复外排。本项目改造采用A/A/O+MBR膜生物反应器为主体工艺，该反应器内的微生物可保持控制在8 000～15 000 mg/L的超高浓度，可以提高系统的有机负荷，使污染物分解彻底；同时系统的产泥量少；由于膜的分离作用，能够高效地进行固液分离，出水悬浮物和浊度接近于零，对于出水水质要求高或回用非常合适，出水水质非常稳定。     

余姚小曹娥污水处理厂升级改造工程设计案例分析

余姚市小曹娥城市污水处理厂一、二期工程处理规模为15万m~3/d,设计出水水质执行《城镇污水处理厂污染物排放标准》 GB 18918—2002)一级A排放标准,三期改造工程扩建规模为7.5万m~3/d,设计出水水质执行一级A标准。为了强化脱氮,改造工程新建生物反应池采用Bardenpho工艺,针对厂区用地紧张的特点,新建二沉池采用矩形周进周出沉淀池(与生物反应池合建)。改造工程总平面布置预留远期处理规模至30万m~3/d,出水标准至"准Ⅳ类水"的用地。文中介绍了三期改造工程工艺设计参数,并分析改造后的运行效果。     

库区某污水处理厂提标改造设计

库区某污水处理厂提标改造工程设计建设规模为30000 m~3/d。针对污水特点和提标要求,该工程处理工艺采用:A/A/O+MBR工艺,污泥处理采用机械浓缩脱水工艺,臭气采用生物过滤法工艺。详细介绍了进、出水水质及提标工艺流程、主要设计参数,出水水质最终满足《城镇污水处理厂污染物排放标准》(GB 18918—2002)中的一级A标准,相关经验可供类似工程参考借鉴。     

A2/O-MBR用于类地表Ⅳ类水排放标准升级改造工程

沈阳市某城镇污水处理厂设计规模为2×10⁴ m³/d,原采用浮动生化床+人工湿地工艺,出水指标执行污水综合排放标准（GB 8978-1996）一级A标准。为了使出水水质达到类地表Ⅳ类水标准,污水处理厂采用A²/O+MBR工艺进行升级改造。改造后,平均出水COD、BOD₅为10.6、4.47 mg/L,氨氮、总氮、总磷和悬浮物平均出水质量浓度分别为0.16、8.52、0.07、0.72 mg/L。在进水水温低于12℃时,仍然具有良好的处理效果。通过优化控制溶解氧,平均电耗和乙酸钠消耗分别降低了9.38%和12.1%,实现了节能降耗。     

A~2/O系统生物添加强化硝化研究

按城市污水处理厂污水和污泥水水量比例设计A2/O污水处理系统和O/A污泥水处理中试系统。试验采用城市污水厂污水和污泥水,将O/A系统所产生的剩余污泥添加至A2/O系统,考察生物添加强化硝化效果。研究结果表明,在相同的温度条件下,对氨氮的去除率可以提高30%以上,氨氧化速率(AUR)和亚硝酸盐氧化速率(NUR)分别从生物添加前的2.61 mg/(g·h)和2.38 mg/(g·h)提高到5.32 mg/(g·h)和3.81 mg/(g·h),分别为生物添加前的2.04倍和1.60倍。     

两级A/O工艺处理生活污水脱氮除磷试验

针对传统A2/O工艺存在的泥龄矛盾,将脱氮和除磷分置于前后2套不同的A/O系统中,第一级A/O采用活性污泥法除磷;第二级A/O采用生物膜法脱氮。以生活污水为处理对象进行试验研究。结果表明,在泥龄为6 d、水温为22～28℃,进水NH3-N、TP、COD的质量浓度分别为40～70、2.0～6.0、150～320 mg/L条件下,出水NH3-N、TP、COD的平均质量浓度分别为5.9、1.0、40 mg/L,均达到了城镇污水处理厂污染物排放标准(GB18918-2002)中的一级排放标准,其去除率分别为82.5%、69.7%、83.1%。     

DCP（M）A、DPO（M）A的性能特点与应用

介绍了DCP(M)A和DPO(M)A四种多功能单体的物理与聚合性能.分别论述了它们进行的普通自由基聚合、氧化自由基聚合、紫外光固化、后交联、接枝共聚与负离子聚合的特点,以及在生产上的应用.     

Effects of calcination condition on expansion property of MgO-type expansive agent used in cement-based materials

Previous research indicated that the expansion property of MgO-type expansive agent (MEA) depended strongly on the calcining conditions, i.e. kiln temperature and residence time. However, the intrinsic effect of calcination condition on the expansion property of MEA has not been clearly demonstrated. In the present work, the effects of calcination condition on the microstructure, hydration activity, and expansion property of MEA have been investigated, and their correlations are also studied. Results indicate that the microstructure of MEA is the intrinsic factor that controlling its expansion property, which is influenced by the calcination condition. MEA produced under higher temperature and longer residence time has less interior pores, larger crystal size of MgO, and smaller specific surface area, thus resulting in lower hydration activity and slower expansion at early age, but larger “ultimate” expansion at late age. While, a new expansion model of MEA is proposed to explain these results.     

Photocatalytic degradation of air pollutants — From modeling to large scale application

Indoor as well as outdoor air quality and their limiting values remain a major problem to our present-day society.This paper addresses the modeling of the decomposition process of nitrogen monoxide (NO) on reactive concrete surfaces under the controlled exposition of a UV source. Within this model the external mass transfer of the pollutant and the internal molecule diffusion-reaction were considered. A first-order kinetics equation is derived with respect to the NO concentration and a site-competitive adsorption between NO/NO₂ and water molecules, resulting in a dependence of the reaction kinetics on the relative humidity. Using the proposed model, a reaction rate constant k and an adsorption equilibrium constant K_d can be derived which describe an active paving stone accurately. Experimental results from a self-developed photoreactor with continuous flow mode were used to validate the proposed kinetic expression. Furthermore, the effect of variations in process conditions such as irradiance and relative humidity on the two constants k and K_d is investigated. All modeling work provides a sound foundation for the translation of this process to real outside conditions. In this regard an upcoming project in a Dutch city is described in brief.     

Comparison between microwave and conventional calcination techniques in regard to reactivity and morphology of co-precipitated BaTiO3 powder,and the electrical and energy storage properties of the sintered samples

Barium titanate (BaTiO₃) nanopowders were synthesized by an aqueous co-precipitation method followed by calcination. Either 2.45 GHz microwaves or conventional heating was used in order to investigate the impact of these techniques on the synthesis time, microstructure, and electrical properties of the materials. The heating temperatures ranged from 620 °C to 810 °C. X-ray diffraction (XRD) revealed pure BaTiO₃ formation by microwave heating in a noticeably shorter time (five minutes) compared to conventional heating (3 h). Field emission scanning electron microscopy (FESEM) results confirmed that the microwave process led to nanocube formation, whereas in the conventional procedure, the particles tended to form spherical shapes. To evaluate the electrical properties, the samples heated at 620 °C were conventionally sintered at 1280 °C, 1330 °C, and 1380 °C. Higher dielectric, piezoelectric, and ferroelectric properties and more energy-saving efficiency (ε_r=1012, tan δ=0.035 d₃₃=85 pC/N, p_r=6.2 µC/cm² and η=48% respectively) were achieved in the microwave-heated BaTiO₃ sintered at 1380 °C compared to the conventionally heated BaTiO₃ (ε_r=824, tan δ=0.030 d₃₃=75 pC/N, p_r=5 µC/cm² and η=27%) demonstrating that microwave calcination substantially affects the final electrical properties.     

用生物化学方法处理城市生活污水

通过对西宁市的地形、水文、气候、水质等多方面的分析,及各种水处理工艺的比较,结合当地的实际情况,选择出了适宜治理西宁市生活污水的A/A/O-曝气生物滤池工艺。     

A method based on isothermal calorimetry to quantify the influence of moisture on the hydration rate of young cement pastes

Cement hydration needs water to proceed and if water is lost by drying, the hydration rate will decrease. This can be of importance in cases when concrete surfaces are exposed to drying so that their strength development will be retarded. We describe a method based on isothermal calorimetry to assess how the rate of cement hydration is influenced by removal of water (drying) at different times up to three days after mixing. Thin samples of cement pastes are hydrated in a calorimeter and at different times exposed to one hour drying periods. The resulting decrease in thermal power following the removal of water is quantified as a measure of the reduction in hydration rate. The mass loss is found by weighing the samples before and after a measurement, and the change in water activity of a sample during drying can be found from the slope of the thermal power during the drying period.     

Material and environmental parameter effects on the leaching of cement pastes: Experiments and modelling

Results already published on the leaching of cement pastes have shown that the kinetics depends sensitively on the material and environment. However and because of the variability of the tested materials and leaching protocols, it is difficult to compare these data and quantify the effect of each parameter. In this paper, a large experimental database on the leaching kinetics of cement pastes is built. Four parameters are investigated: type of cement (portland cement, silica fume cement, slag cement, ternary cement with slag and fly ash); water-to-cement ratio (0.5; 0.4; 0.25), temperature (26 °C; 72 °C; 85 °C) and chemical composition of the leaching solution (pure water, mineralised water, ammonium nitrate solution). Firstly, the database is used to calculate the leaching kinetics of the cementitious materials. Secondly, a simplified model predicting the one-dimensional leaching kinetics for other water-to-cement ratios and temperature up to 85 °C is presented.     

电解-A/0法处理酱菜废水研究

以酱菜废水作为研究水质,分别研究了电解法、厌氧、好氧活性污泥法处理酱菜废水;联用处理酱菜废水的COD、氨氮和色度的去除率分别为93.2%、98%和92%。