采用塔式反应器处理地面水中亚硝酸盐的研究

考察了塔式反应器中臭氧对地面水中亚硝酸盐氧化的工艺条件，得到了将亚硝酸盐氮含量为0.21mg／L的地面水处理到符合“地面水环境质量标准”Ⅰ、Ⅱ、Ⅲ类水的最佳工艺条件。研究表明，该工艺不受水温影响，有较好稳定性，且设备简单、处理费用低。     

应用离子选择电极测定水中硝酸盐

硝酸盐在细菌的作用下可被还原成亚硝酸盐。在适当条件下,亚硝酸盐和二级胺、三级胺合成N—亚硝基化合物。这种化合物对动物具有致癌作用。因此对饮用水、地面水、废水中硝酸盐的监测是很有     

亚硝酸盐水溶液稳定性研究

对于亚硝酸盐标准溶液,据各文献报导,高浓度的亚硝酸盐标准储备液应经常标定,低浓度的亚硝酸盐标准使用液应临时标定、配制。本文对标准亚硝酸盐高浓度的储备液与低浓度的使用液的稳定性进行了考察。实验结果表明:亚硝酸盐标准储备液与使用液均具有相对的稳定性。 地面水样中的亚硝酸盐是水体的污染物之一。亚硝酸盐极不稳定,可被氧化成硝酸盐,也易被还原成氨氮。根据国内外文     

短程硝化过程中NO-2-N高效富集的工艺条件实验研究

针对厌氧氨氧化工艺需要提供充足的亚硝酸盐氮为电子受体的问题,利用培养基对SBR中具有一定短程硝化功能的污泥进行富集培养,得到氨氧化菌和亚硝酸盐氧化菌的数量之比为104︰1,并研究了工艺条件对短程硝化的影响,结果表明,适合氨氧化菌生长的最佳温度为30℃、pH为7.5、nHCO^-₃/nNH⁺₄-N值为1。以适合氨氧化菌生长的最佳环境条件优化SBR,在进水氨氮浓度为250 mg/L时,氨氮的转化率达到90％以上,亚硝酸盐氮积累率维持在85％以上,反应器中氨氧化菌与亚硝酸盐氧化菌的数量之比为10³∶1,亚硝酸盐的高效积累为厌氧氨氧化工艺处理高氨废水的过程提供了稳定的电子受体。     

含亚硝酸盐废水的氧化处理

本文介绍用次氯酸钠氧化废水中亚硝酸盐的处理方法。该法工艺简单、操作方便、反应速度快、氧化效率高。随废水浓度的高低投加不同量的次氯酸钠,使出水中亚硝酸盐含量小于1毫克/升。根据废水量的大小,可连续处理和间歇处理,水可循环利用,日常处理费用低。     

有机磷农药的测定 气相色谱法 水中甲基对硫磷,对硫磷、乐果、马拉硫磷残留量的测定

简介本方法用溶剂萃取法处理水样,用二根不同的色谱柱火焰光度检测器,气相色谱法测定地面水中甲基对硫磷、对硫磷、乐果、马拉硫磷的残留量,不需净化处理,方法简单,快速,灵敏。地面水取样1升,检测下限为:甲基对硫磷0.2ppb;对硫磷为0.3ppb;乐果为0.2ppb;马拉硫磷为0.2ppb。     

实时荧光定量PCR对A2/O短程硝化系统内氨氧化菌的定量分析

通过控制好氧区低DO浓度以及缩短好氧实际水力停留时间(actual hydraulic retention time,AHRT),在处理低C/N比实际生活污水的A2/O工艺中,成功启动并维持了短程硝化反硝化;系统亚硝酸盐积累率稳定维持在90%左右,氨氮去除率在95%以上。通过提取富集氨氧化菌(ammonia oxidizing bacteria,AOB)的基因组DNA,经两次常规PCR扩增和琼脂糖凝胶电泳,以纯化回收的DNA扩增片段作为实时荧光定量PCR检测AOB数量的DNA标准品,建立了检测AOB数量的实时荧光定量PCR标准曲线。利用实时荧光定量PCR技术比较了A2/O系统在不同运行条件及亚硝酸盐积累率情况下AOB菌群数量。结果表明,随着系统亚硝酸盐积累率的上升,系统内AOB菌群数量也大幅上升。全程硝化和短程硝化时,系统内的AOB菌群数量分别为5.28×109cells/g MLVSS和3.95×1010cells/g MLVSS。此外,亚硝酸盐积累率的下降相对于AOB菌群数量的下降有一定的滞后性。     

硫化物抑制亚硝酸氧化菌推动短程硝化反硝化生物脱氮技术

利用硫化物对亚硝酸盐氧化菌的抑制作用,快速建立短程硝化。通过改变供氧条件,硫化物作为电子供体推动自养反硝化,实现同一序批反应器一体化脱氮。采用序批反应器SBR处理模拟市政污水,在DO浓度（1.5±0.5） mg·L-1,硫化物浓度50 mg·L-1,温度25 ℃,水力停留时间12 h的条件下,共运行90 d,控制反应器厌氧低氧时间,达到90%以上的总氮去除率。同时研究了硫化物对短程硝化的抑制作用、最适宜运行pH条件、污泥颗粒大小变化、污泥产生量等。硫化物抑制亚硝酸盐氧化菌推动短程硝化反硝化生物脱氮技术有着反应条件可控性高、短程硝化建立时间短、脱氮效果好等优点,适用于低碳氮比的市政污水处理。     

气水比对曝气生物活性炭处理原水的影响

针对从臭氧-活性炭工艺中开发出来的预臭氧-曝气生物活性炭,在不同气水比工况下进行实验,分析了不同气水比对曝气生物活性炭处理微污染原水的影响与作用。结果表明:在滤速为8～12 m/h,空床接触时间为11.5～15.4 min,装填密度为510 g/L条件下,不同气水比对去除氨氮的影响大于对CODMn的影响。气水比为0.3∶1时,对氨氮浓度为1.65～2.10 mg/L范围的进水平均去除率为81.9%,亚硝酸盐氮平均积累率为1.4%,CODMn去除率为70.6%。当气水比逐渐增加时,氨氮平均去除率有所提高,亚硝酸盐氮积累率则有所下降,对较低浓度的CODMn影响不大。     

固定化氧化还原介体加速亚硝酸盐生物反硝化作用

考察了利用循环伏安法所制备的固定化氧化还原介体(AQS/PPy/ACF)加速亚硝酸盐生物反硝化的特性,及其降解过程中pH和氧化还原电位(ORP)的变化特征。结果表明,AQS/PPy/ACF可显著地加速亚硝酸盐的生物降解;在不考虑各因子间交互作用的条件下,AQS/PPy/ACF加速亚硝酸盐降解的最佳条件为温度35℃,pH=8和碳氮比为6;AQS/PPy/ACF加速亚硝酸盐生物反硝化过程中pH的变化趋势与传统的亚硝酸盐生物反硝化过程中pH的变化趋势相似;AQS/PPy/ACF的加入可使亚硝酸盐生物反硝化过程中的ORP降低约45 mV;AQS/PPy/ACF具有较好的催化稳定性。本研究可为亚硝酸盐的生物降解提供新的技术途径,并为该技术的实际应用提供理论基础。     

集水花坛对农村区域初期地表径流的净化效果

针对农村集中居住区地表硬化,高氮磷浓度的初期地表径流直排进而污染附近河道的问题,设计了“集水花坛-拦截沟”组合工艺,研究了4个不同水力停留时间(HRT)下处理初期地表径流的净化效果。结果表明：“集水花坛-拦截沟”组合工艺利用植物吸收、微生物降解及基质层吸附拦截的综合作用,有效降低了农村初期地表径流中的污染物浓度;在4种HRT条件下,该组合工艺均可快速去除径流水体中的悬浮物SS,去除率达96%以上;当HRT为3 d时,该组合工艺能够显著降低径流水体中的TN、TP及COD值,去除率分别达到90%、90%和75%以上,且出水TN和COD达到《地表水环境质量标准》(GB 3838-2002)Ⅲ类水标准,TP浓度达到V类水标准。以上结果可为农村初期地表径流的处理提供技术参考和数据支撑。     

水厂常规工艺去除有机物和总磷

有机物、总磷是我国地表水源主要污染物,涉及范围广,污染浓度高,是影响水厂出水安全的重要因素。以某水厂净水系统为依托,分析水厂常规工艺对有机物和总磷的去除效果及影响因素。研究表明,地表水源水厂所采用的混凝+沉淀+过滤+消毒的传统工艺对有机物的去除率不高,在22.1%～61.3%之间,平均去除率为38.3%;其中,混凝沉淀是常规工艺中去除CODMn的关键环节,占总去除效果的43%～68%,过滤环节去除率约为10%;温度和混凝剂投加量是影响CODMn去除效果的主要因素。常规工艺对总磷的去除效果较好,去除率约为60%～90%,冬季略低,其他季节略高;混凝沉淀单元与过滤单元对总磷均有较好的去除效果,去除率分别为25%～77%和40%～76%。在当前水质条件下,水厂现行工艺可满足常规状况下有机物和总磷的去除需要。     

Drugs in the environment: emission of drugs, diagnostic aids and disinfectants into wastewater by hospitals in relation to other sources--a review.

After administration, pharmaceuticals are excreted by the patients into wastewater. Unused medications are sometimes disposed of in drains. The drugs enter the aquatic environment and eventually reach drinking water if they are not biodegraded or eliminated during sewage treatment. Additionally, antibiotics and disinfectants are supposed to disturb the wastewater treatment process and the microbial ecology in surface waters. Furthermore, resistant bacteria may be selected in the aeration tanks of STPs by the antibiotic substances present. Recently, pharmaceuticals have been detected in surface water, ground water and drinking water. However, only little is known about the significance of emissions from households and hospitals. A brief summary of input by different sources, occurrence, and elimination of different pharmaceutical groups such as antibiotics, anti-tumour drugs, anaesthetics and contrast media as well as AOX resulting from hospital effluent input into sewage water and surface water will be presented.     

宽叶香蒲表面流人工湿地脱氮除磷效果研究

以运行A/O工艺的生化反应器出水为处理对象,在中试规模上研究了宽叶香蒲表面流人工湿地的脱氮除磷效果及影响因素.结果表明,在工况Ⅰ条件下,COD去除率为43.2%,COD面积负荷去除率为4.79 g/(m2·d),COD面积负荷去除率常数为0.18 m/d,SS、NH4+-N和NO-3-N的去除率分别为41.2%、9.4%、3.4%,TN去除率为11.8%,TN面积负荷去除率为1.36g/(m2·d),TN面积负荷去除率常数为0.04 m/d,TP去除率为30.1%,TP面积负荷去除率为0.29 g/(m2·d),TP面积负荷去除率常数为0.13 m/d;在工况Ⅱ条件下,COD去除率为18.7%,COD面积负荷去除率为1.19 g/(m2·d),COD面积负荷去除率常数为0.06 m/d,SS、NH4+-N、NO2--N、NO3--N的去除率分别为31.6%、29.8%、65.0%,29.2%.TN去除率为31.4%,TN面积负荷去除率为2.33 g/(m2·d),TN面积负荷去除率常数为0.12 m/d,TP去除率为29.4%,TP面积负荷去除率为0.22 g/(m2·d),TP面积负荷去除率常数为0.11 m/d.在COD面积负荷去除率,TN面积负荷去除率、TP面积负荷去除率分别为4.90～9.80、2.76～8.83、0.57～1.39 g/(m2·d),水力停留时间(HRT)为0.4～1.1 d条件下,随HRT,水温、(NO2+-N+NO3--N)/TN的增加,表面流人工湿地的TN面积负荷去除率线性增加.     

Applicability of MIEX®DOC process for organics removal from NOM laden water

The aim of this study was to evaluate applicability of ion exchange process for organics removal from Douro River surface water at the intake of Lever water treatment plant using magnetized ion exchange resin MIEX®. Qualitative analysis of the natural organic matter present in the surface water and prediction of its amenability to removal in conventional coagulation process were assessed. Results obtained in MIEX®DOC process kinetic batch experiments allowed determination of ion exchange efficiency in dissolved organic carbon (DOC), UV absorbing organics, and true color removal. The data were compared with the efficiencies of the conventional unit processes for organics removal at Lever WTP. MIEX®DOC process revealed to be more efficient in DOC removal than conventional treatment achieving the efficiencies in the range of 61–91 %, lowering disinfection by-products formation potential of the water. DOC removal efficiency at Lever WTP depends largely on the raw water quality and ranges from 28 % for water of moderated quality to 89 % of significantly deteriorated quality. In this work, MIEX®DOC process was also used as a reference method for the determination of contribution of anionic fraction to dissolved organic matter and selectivity of the unit processes at Lever WTP for its removal.     

Investigation of the production of lipophilic volatile organohalogen materials during laboratory chlorination of some ground water samples from Yugoslavia

Water chlorination leads to the generation of various halogenated products of natural and waste water organic matter. In natural surface and ground water humic matter usually makes the greatest part of the total organic matter. However, in the water polluted with various organic wastes, other organic matter is also present in significant concentrations. The investigation of the relationship between the concentration of organic matter in the samples of ground water in Yugoslavia on one side, and the production of the lipophilic volatile organohalogen materials during the process of their chlorination on the other side is described. The production of the halomethanes and other ECD response materials during the chlorination of water samples in laboratory conditions is compared with the concentrations of organic materials in water samples. From the obtained linear correlation coefficients, possibilities of predicting amounts of organohalides during the chlorination process by using several very simple methods for the organic materials estimation in the investigated water samples are discussed and compared.     

Storm water runoff concentration matrix for urban areas

The infrastructure (roads, sidewalk, commercial and residential structures) added during the land development and urbanisation process is designed to collect precipitation and convey it out of the watershed, typically in existing surface water channels, such as streams and rivers. The quality of surface water, seepage water and ground water is influenced by pollutants that collect on impervious surfaces and that are carried by urban storm water runoff. Heavy metals, e.g. lead (Pb), zinc (Zn), copper (Cu), cadmium (Cd), polycyclic aromatic hydrocarbons (PAH), mineral oil hydrocarbons (MOH) and readily soluble salts in runoff, contribute to the degradation of water. An intensive literature search on the distribution and concentration of the surface-dependent runoff water has been compiled. Concentration variations of several pollutants derived from different surfaces have been averaged. More than 300 references providing about 1300 data for different pollutants culminate in a representative concentration matrix consisting of medians and extreme values. This matrix can be applied to long-term valuations and numerical modelling of storm water treatment facilities.     

A review on bisphenol A occurrences,health effects and treatment process via membrane technology for drinking water

Massive utilization of bisphenol A (BPA) in the industrial production of polycarbonate plastics has led to the occurrence of this compound (at μg/L to ng/L level) in the water treatment plant. Nowadays, the presence of BPA in drinking water sources is a major concern among society because BPA is one of the endocrine disruption compounds (EDCs) that can cause hazard to human health even at extremely low concentration level. Parallel to these issues, membrane technology has emerged as the most feasible treatment process to eliminate this recalcitrant contaminant via physical separation mechanism. This paper reviews the occurrences and effects of BPA toward living organisms as well as the application of membrane technology for their removal in water treatment plant. The potential applications of using polymeric membranes for BPA removal are also discussed. Literature revealed that modifying membrane surface using blending approach is the simple yet effective method to improve membrane properties with respect to BPA removal without compromising water permeability. The regeneration process helps in maintaining the performances of membrane at desired level. The application of large-scale membrane process in treatment plant shows the feasibility of the technology for removing BPA and possible future prospect in water treatment process.     

Comparison of the solution behaviour of a pyrite-calcite mixture in batch and unsaturated sand column

A successful application of reaction transport algorithms to calculate the chemical evolution of natural systems requires accurate methods to compute the rates of mineral/fluid surface reactions. Regarding the transport of radio-nuclides in mining dumps the dissolution of minerals is of special importance. Using a kinetic rate law of the mineral dissolution verified for unsaturated conditions will allow a realistic modelling of the mineral weathering in the environment. Dissolution rates of minerals in an aqueous solution are determined by several characteristics. These are surface reaction rates, morphology of the mineral's surface and, in case it is the unsaturated zone, the degree of the water saturation. For this process, the quantity of the particle surfaces which are in contact with percolating water is most decisive. In order to study the differences of mineral dissolution under saturated and unsaturated conditions batch and column experiments were carried out with a pyrite-calcite mixture. The experimental results were verified by calculations. Comparing the dissolution in batch with those in the column experiment, which was performed with a water flow velocity of 0.64 cm/day and was analyzed in the region of a water saturation of 0.11, one can conclude that only a small portion of about 5% of the grain surface is chemically reactive in this unsaturated flow.