废水反硝化除磷技术研究进展

结合近年来国内外最新研究成果,综述了反硝化除磷机理及工艺.重点介绍了反硝化聚磷菌的微生物学特性和除磷特性,以及不同种类的反硝化除磷工艺,并对反硝化除磷技术进行了展望.     

污水除磷技术的现状及发展趋势

随着水体磷污染的日益加剧和排放标准的进一步严格化,研究开发经济、高效的污水除磷技术已成为当今污染控制工程领域的研究重点和热点.在分析、评价污水除磷技术现状的基础上探讨了它的发展趋势.     

复合式活性污泥缺氧聚磷生物膜硝化同步除磷脱氮

该发明提供了一种复合式活性污泥缺氧聚磷生物膜硝化同步除磷脱氮的方法。具体步骤如下：废水首先进入接触池，与沉淀池回流的富含聚磷菌的活性污泥短暂混合，控制水力停留时间5—10min，将污泥中携带的少量硝酸盐迅速反硝化；接触池出水进入厌氧池，在厌氧池中反硝化聚磷菌吸收大量的低相对分子质量的有机物，以聚-β-羟基烷酸酯形式贮存在体内，同时释放磷；含有氨氮、磷、少量剩余有机物和已释放磷的聚磷菌的泥水混合液进入缺氧池，与沉淀后回流的含有硝酸盐的上层清液混合，反硝化聚磷菌以硝酸盐为电子受体进行反硝化聚磷；缺氧池出水进入固定安装有半软性填料的生物膜-活性污泥复合式好氧池中，     

活性污泥生物除磷数学模型研究进展

概述了活性污泥生物除磷过程的Comeau／Wentzel模式和Mino模式，以及以Wentzel和Smolders为代表的两类生物除磷数学模型，提出结合Smolders模型与ASM2、ASM2D模型的优点建立结构完整、参数较少、辨识简单的模型，是生物除磷数学模型发展的方向。     

DO对同步硝化反硝化协同除磷的影响

采用序批式活性污泥反应器(SBR)处理模拟城市污水,在厌氧--好氧运行方式下,考察了DO对同步硝化反硝化协同除磷效果的影响.结果表明,DO的变化对该系统中有机物的去除影响不显著,当DO为1.5～2.0 mg/L时,TN及TP去除率均能达到90%以上,并可以应用pH曲线拐点来判断系统硝化过程是否完成.     

制药废水硝化-反硝化除氮研究

含高浓度氮的制药废水经好氧生化处理后,虽然出水的ＣＯＤ,ＢＯＤ５均可达到行业排放标准,但ＴＮ仍高达约１７０ｍｇ／Ｌ。本研究在曝气池中设置填料,利用生物膜外层好氧,内层缺氧厌氧的条件,使硝化－反硝化脱氮在同一构筑物内进行,ＮＨ３－Ｎ和ＴＮ去除率分别可达约９０％和７０％。在本试验条件范围内,温度越高,负荷越低,硝化和反硝化作用越完全,ＮＨ３－Ｎ和ＴＮ去除率越高。     

高效除磷材料的除磷特性研究

研究了高效除磷材料(Efficient Phosphorus Removal Composite,EPRC)的除磷特性,以及以此材料为填料的吸附柱对模拟含磷废水的除磷效果.试验结果表明: EPRC颗粒在15℃、25℃、35℃时的最大饱和吸附量分别达到1.9535mg/g、2.281mg/g、3.6724mg/g.以EPRC颗粒填充吸附柱处理模拟含磷废水时,停留时间8h、连续进水、运行8d,磷的平均去除率为93%,废水pH值略有升高.     

高炉渣吸附除磷研究

针对生物除磷不稳定,化学除磷泥量大,成本高的弱点,从除磷吸附剂角度,研究了炼铁厂高炉渣去除磷酸盐的性能.通过对高炉渣活化以及高炉渣滤床的试验,结果表明,高炉渣中存在能与磷酸根生成沉淀的铁、钙等离子或其络合物,高炉渣细小多孔性构造又能吸附此类沉淀物,因此高炉渣对磷酸根有较高的沉淀吸附功能.     

膜生物反应器在废水脱氮除磷中的应用

介绍了两种膜生物反应器（MBR）脱氮除磷工艺：单一反应器间歇曝气MBR工艺和厌氧一好氧MBR工艺。总结了MBR脱氮除磷工艺的国内外研究进展、工艺特点及处理效果,重点探讨了MBR脱氮除磷工艺中同步硝化反硝化、短程硝化反硝化及反硝化除磷的机理,并指出了今后MBR脱氮除磷进一步研究的重点及方向。     

反硝化聚磷菌的培养及其脱氮除磷特性

采用SBR反应器驯化培养反硝化聚磷菌,考察了厌氧-缺氧-好氧和厌氧-缺氧运行模式下反硝化聚磷菌的增殖情况、反应器的脱氮除磷特性及胞内聚合物聚β-羟基丁酸(PHB)和糖原的合成消耗情况。实验结果表明:经过72 d(288个周期)的驯化培养,SBR反应器内反硝化聚磷菌的数量约占全部聚磷菌的84.5%;厌氧-缺氧培养方式下,反硝化聚磷菌的释磷速率为34.5 mg/(L·h),缺氧吸磷速率为23.0 mg/(L·h),缺氧阶段每降解1.0 mg/L的PO_4~(3-)-P需要消耗1.0 mg/L的NO_3~--N;每消耗6.3 mg/L的COD生成1 mg/g的PHB,每降解1 mol的PHB约生成0.73 mol的糖原。     

三种填料对生活污水中磷的去除效果研究

研究了沙子、砾石、珍珠岩三种填料对生活污水中磷的去除效果.结果表明:沙子对污水中总磷(TP)的去除效果最好,出水中TP的含量小于1.0 mg/L;砾石次之,珍珠岩的去除效果最差.三种填料对生活污水中TP的平均去除率分别为76.2%、37.7%和26.1%.     

钢渣净化水中磷素的研究进展

在对国内外钢渣除磷研究现状进行总结的基础上,介绍了铜渣的组成及其物理、化学性质,并进一步阐述了其在除磷过程中涉及到的反应机理,提出了钢渣应用于含磷废水处理时存在的问题及今后的研究发展方向。     

污水除磷技术的研究与进展

详细介绍了污水除磷的迫切性及传统的污水除磷工艺原理与特点，阐述了污水除磷技术的最新发展动向。     

Transformation of phosphorus during drying and roasting of sewage sludge

Sewage sludge (SS), a by-product of wastewater treatment, consists of highly concentrated organic and inorganic pollutants, including phosphorus (P). In this study, P with different chemical fractions in SS under different drying and roasting temperatures was investigated with the use of appropriate standards, measurements, and testing protocol. The drying and roasting treatment of SS was conducted in a laboratory-scale furnace. Two types of SS samples under different treatment temperatures were analyzed by ³¹P NMR spectroscopy. These samples were dried by a vacuum freeze dryer at ?50 °C and a thermoelectric thermostat drying box at 105 °C. Results show that the inorganic P (IP) content increased as the organic P content decreased, and the bio-availability of P increased because IP is a form of phosphorous that can be directly absorbed by plants. ³¹P NMR analysis results indicate the change in P fractions at different temperatures. Non-apatite P was the dominant form of P under low-temperature drying and roasting, whereas apatite P was the major one under high-temperature drying and roasting. Results indicate that temperature affects the transformation of P.     

镍对活性污泥生物除磷的影响及其机理

以实际生活污水为研究对象,在序批式活性污泥反应器中探究了Ni2+对活性污泥形态及生物除磷性能的影响。实验结果表明,Ni2+能够抑制生物除磷,当Ni2+质量浓度由0 mg/L增加至10.0 mg/L时,PO43--P去除率由93%下降至12%。机理研究结果表明：Ni2+能抑制聚磷微生物的厌氧释磷和好氧吸磷,并能抑制内聚物聚羟基烷酸酯（PHA）的合成;当Ni2+质量浓度为10.0 mg/L时,PHA的最大含量仅为2.4 mmol/g （以单位质量挥发性悬浮物所含PHA中C的物质的量计）,远低于空白组中PHA的含量。此外,Ni2+还对微生物群落的组成产生影响,并促进活性污泥中聚糖微生物的增殖。     

Phosphorus recovery from sewage sludge ash through an electrodialytic process

The electrodialytic separation process (ED) was applied to sewage sludge ash (SSA) aiming at phosphorus (P) recovery. As the SSA may have high heavy metals contents, their removal was also assessed. Two SSA were sampled, one immediately after incineration (SA) and the other from an open deposit (SB). Both samples were ED treated as stirred suspensions in sulphuric acid for 3, 7 and 14 days. After 14 days, phosphorus was mainly mobilized towards the anode end (approx. 60% in the SA and 70% in the SB), whereas heavy metals mainly electromigrated towards the cathode end. The anolyte presented a composition of 98% of P, mainly as orthophosphate, and 2% of heavy metals. The highest heavy metal removal was achieved for Cu (ca. 80%) and the lowest for Pb and Fe (between 4% and 6%). The ED showed to be a viable method for phosphorus recovery from SSA, as it promotes the separation of P from the heavy metals.     

Experimental study of the bio-oil production from sewage sludge by supercritical conversion process

Environment-friendly treatment of sewage sludge has become tremendously important. Conversion of sewage sludge into energy products by environment-friendly conversion process, with its energy recovery and environmental benefits, is being paid significant attention. Direct liquefaction of sewage sludge into bio-oils with supercritical water (SCW) was therefore put forward in this study, as de-water usually requiring intensive energy input is not necessary in this direct liquefaction. Supercritical water may act as a strong solvent and also a reactant, as well as catalyst promoting reaction process. Experiments were carried out in a self designed high-pressure reaction system with varying operating conditions. Through orthogonal experiments, it was found that temperature and residence time dominated on bio-oil yield compared with other operating parameters. Temperature from 350 to 500 °C and reaction residence time of 0, 30, 60 min were accordingly investigated in details, respectively. Under supercritical conversion, the maximum bio-oil yield could achieve 39.73%, which was performed at 375 °C and 0 min reaction residence time. Meanwhile, function of supercritical water was concluded. Fuel property analysis showed the potential of bio-oil application as crude fuel.     

Gaseous emissions from ceramics manufactured with urban sewage sludge during firing processes

The re-use of sewage sludge without any treatment as primary material-mixed with clays-in order to obtain structural ceramics for buildings has been successfully improved. In the Ecobrick project, the firing of a mixture of specific percentages of three components (clays, sludges and forest debris) resulted in a lighter and more thermal and acoustic insulating brick, compared with conventional clay-bricks. Volatile organic compounds (VOC) emission from the manufacturing of ceramics is the most important aspect to control. In the Ecobrick project VOC emissions were monitored by using a bench-scale furnace. The study was conducted using an EPA recommended sampling train and portable sampling tubes that were thermally desorbed and analyzed by gas chromatography/mass spectrometry. Drying of raw sewage-sludge and firing processes were considered separately. In this paper, we present VOC emissions coming from the firing step of the Ecobrick production.