氨氮复合污染含铁、锰地下水生物净化工程的启动运行

近年来,氨氮复合污染含铁、锰地下水的净化成为研究热点,铁、锰、氨氮各自的氧化特性造成功能微生物在滤层中争夺溶解氧(DO)和生存空间,给除锰生物滤层的培养与运行造成较大影响。工程采用无阀滤池基于双层滤料成功实现了铁、锰、氨氮的一级生物净化。文中介绍了工程概况、生物滤层的培养过程以及铁、锰、氨氮的去除过程,并追踪了生物滤层中磷酸盐的去除情况。研究结果表明:不到两周净化滤层达到了进水中Fe²⁺的深度去除,出水总铁含量稳定在0.2 mg/L以下;不到两个月氨氮和锰实现稳定去除,出水Mn²⁺含量小于0.1 mg/L,氨氮含量在0.2 mg/L左右;进水中的磷酸盐在滤层中由于铁氧化物的吸附得到深度净化,出水含量低于10μg/L。     

温度对生物净化滤柱中氨氮、铁、锰去除效果的影响

温度是生物净化滤柱运行的一个重要参数,采用生物净化滤柱处理模拟含氨氮、铁、锰地下水,考察水温从约25℃降到约6℃过程中氨氮、铁、锰的去除效果。结果表明,出水氨氮、总铁、锰的浓度分别低于0.15mg/L、0.1mg/L、0.05mg/L,均低于国家标准。出水总铁、锰均未受到水温下降的影响,但是出水氨氮浓度逐渐从约0.02mg/L升高到约0.12mg/L。进一步分析发现,铁主要在滤层的0~0.4m段去除,去除效果没有受到水温变化的影响。氨氮、锰主要在滤层的0~0.8m段去除,其沿程浓度均随水温降低而明显升高。氨氮、锰的生物去除符合一级动力学反应,水温为24.6℃、15.3℃、6.7℃时,两者的动力学常数k分别为0.154min^-1、0.186min^-1,0.143min^-1、0.175min^-1,0.103min^-1、0.163min^-1;半反应时间t_1/2分别为4.51min、3.72min,4.83min、3.96min,6.72min、4.24min。随着试验水温的降低,氨氮、锰的去除效果明显受到影响。     

生物接触氧化法处理复合型微污染地下水沿程变化规律

为研究不同滤层下处理复合型微污染地下水的效果,采用锰砂-陶粒-锰砂为滤料的三级曝气-生物接触氧化法,研究了全跌水曝气方式和全机械曝气方式的滤速分别为2、3、4、5、6 m/h时,滤层沿程出水水质情况。结果为全机械曝气滤柱在各滤速下,出水铁（Fe）、锰（Mn）、氨氮和高锰酸盐4项指数均能达标。全跌水曝气滤速为2 m/h时,出水4项指标均能达标;滤速为3、4 m/h时,仅出水Fe达标,Mn和氨氮不能达标。表明水中Fe在经过1500 mm滤层以后均能达标,增加曝气装置,不仅能够提升水中Mn、氨氮和有机物的去除空间,还能提高水中Mn、氨氮和有机物的去除率。     

Fe~(2+)对成熟滤柱除锰效果的影响

以哈尔滨呼兰区某地含高浓度铁锰地下水为处理对象,模拟实际情况中突发性Fe~(2+)污染对成熟滤柱除锰效果的影响。分别进行了曝气失效,Fe~(2+)浓度增大,滤速增大实验。实验结果表明:曝气失效的滤柱受Fe~(2+)污染后,出水锰增加,恢复曝气,6d后滤柱恢复除锰能力,出水锰达标(锰含量小于0.1mg/L);Fe~(2+)浓度从0.58mg/L逐步增加至2.09mg/L时,滤柱出现出水锰不达标情况,恢复至上一浓度1.56mg/L时,经过4d,出水锰达标;滤速从1m/h逐渐增大到5m/h,出水锰不达标,恢复至上一速度4m/h,经过7d,出水锰达标。     

滤层曝气对炭砂双层滤池去除氨氮的影响

通过现场中试试验,考察了不同气水比和曝气深度下滤层曝气对炭砂生物滤池氨氮去除效果的影响。试验结果表明滤池对氨氮去除量随着气水比和曝气深度的增加呈现出先增加后不变的趋势,炭砂双层滤池对NH3-N的去除限为2．8～3．0mg／L。在滤池某一深度进行曝气,当气水比小于0．1时,增加气水比,增大的是滤池0～0．5m滤段滤料对氨氮的去除;当气水比为0．1～0．25时,增加气水比,增加的是0．5～0．9m滤段滤料对氨氮的去除。充足的气水比条件下,在0．4m深度以上曝气,提高的是0～0．5m滤段的氨氮去除效果,在0．4～0．8m深度曝气,提高的是0．5～0．9m的氨氮去除效果,0．9m滤段以下滤料对氨氮基本没有去除作用。为保证出水浊度,建议在滤池0．6m深度对滤池进行曝气。     

铁对生物滤柱中锰、氨氮去除效果的影响研究

由于不同地区的地下水中总铁浓度差别很大,考察了进水总铁升高对生物滤柱中锰、氨氮去除效果的影响。研究结果表明:当进水总铁约1 mg/L,锰、氨氮分别约2、1.3 mg/L时,铁、锰、氨氮均有很好的去除效果,出水总铁、锰、氨氮分别为0.077、0.041、0.032 mg/L;当进水总铁升高到约5、10 mg/L时,锰、氨氮的去除效果受到明显影响,但在稳定阶段,锰、氨氮又降到了国家标准以下。沿程分析发现,铁、氨氮均从滤层顶部开始去除,当二价铁全部氧化后锰开始去除;随着进水总铁的升高,锰、氨氮的去除区域均明显向下延伸。     

两种典型滤料厌氧氨氧化效果与工艺运行优化

为促进厌氧氨氧化在城市污水处理中的应用, 针对陶粒和火山岩两种典型滤料滤池的厌氧氨氧化脱氮效果和关键性工艺参数进行了研究。试验结果表明, 接种挂膜启动生物滤池, 10 d可实现稳定的厌氧氨氧化生物膜, 火山岩滤池生物膜量和EPS均高于陶粒。滤料和反冲洗对厌氧氨氧化滤池实现稳定脱氮具有重要影响, 低滤速条件下火山岩和陶粒滤池厌氧氨氧化效果基本相同, 火山岩滤池和陶粒滤池反冲洗周期均较长, 宜采用单独水冲方式;但高滤速条件下火山岩滤池比陶粒滤池更易堵塞, 滤层有效深度小, 反冲洗方式宜采用气水联合反冲方式, 并相应缩短反冲洗周期、延长反冲洗时间。火山岩和陶粒滤池滤速均不宜高于2 m·h^-1, 最高总氮负荷分别可达3.81 kg·m^-3·d^-1和3.56 kg·m^-3·d^-1。     

地下水生物除铁、锰的影响因素试验研究

目的：研究锰砂滤层去除铁、锰过程中滤速、温度、溶解氧3个因素对去除效果的影响,为生物法除铁、锰的实际运行提供了参考依据。方法：在其他运行条件相同的情况下,只改变其中一项,进行去除率试验对比。结论：（1）当处理只有铁超标的地下水时,滤速可以适当提高,锰超标时,出水中的含锰量是选择过滤速度的主要的控制指标;（2）DO在一定范围内的变化对生物除铁除锰效率的提高无显著影响。从经济性和微生物角度考虑原水DO维持在3mg／L左右既可满足运行要求;（3）当铁锰共存时,最适宜的处理环境温度为20℃。     

溶解氧对生物滤柱中氨氮、铁、锰去除效果的影响

为了研究溶解氧变化对生物滤柱中氨氮、铁、锰去除效果的影响,将进水溶解氧从约10.5mg/L逐步降到7mg/L,本文考察了氨氮、铁、锰的变化规律。结果表明：当溶解氧为约10.5mg/L时,出水氨氮、总铁、锰分别为0.050mg/L、0.065mg/L、0.022mg/L,氨氮、铁、锰分别主要在滤层的0～1.2m、0～0.4m、0～1.2m去除。当溶解氧降到约9mg/L、8mg/L、7mg/L时,出水总铁均低于0.1mg/L;出水锰先明显升高,后又降到了0.05mg/L以下;出水氨氮分别升高到0.17mg/L、0.41mg/L、0.61mg/L。溶解氧不足时,铁主要在溶解氧充足的上部滤层去除;锰氧化菌优先利用溶解氧氧化二价锰,并且锰的氧化速率没有明显降低;氨氮的氧化速率明显降低。生物滤柱可以在较低溶解氧条件下运行,从而降低运行成本。     

接触氧化法和生物法滤柱除铁锰对比实验研究

针对水中铁锰难以去除的问题,参照沈阳市某水厂的水质以人工配水进行接触氧化法和生物氧化法除铁锰工艺实验。结果表明,在相同实验条件下生物法除铁效果更好;当滤速由3 m/h提高到5 m/h时,对2种方法均有影响,对生物法的影响更大;铁的存在对于除锰滤柱是必要的,铁含量较高或者较低都不利于锰的去除,当Fe的质量浓度为3 mg/L时对锰的去除效果最好。出水水质达到GB 5749-2006标准。     

接触氧化除锰滤池的快速启动

以廉价河砂为填料,采用间歇臭氧曝气的方式,使原水中Mn2+迅速被氧化成不溶于水的化合物附着在河砂表面形成具有除锰能力的锰质活性滤膜.在实验室条件下,当间歇臭氧曝气量为50 ml·min-1,每天曝气4次,每次10 min时,仅用5 d即可形成成熟锰质活性滤膜,使出水持续稳定在0.1 mg·L-1以下,大大缩短了除锰滤池...     

螺旋迭错式空间全曲面生物填料流场模拟分析

引言 填料是生物膜法装置的核心组成部分,除了提供生物膜生长的环境,还能过滤水中悬浮物.本课题组于2009年开发出了一种具有螺旋迭错式空间全曲面结构的生物填料(专利号:200920256153.7.以下简称空间全曲面填料).其结构如图1所示,由波纹状的三维全曲面结构PVC薄片构成,具有近似圆锥状的孔隙,使水流紊乱,产生许多旋涡.旋涡使浮游物依密度分离,滞留在填料内部的不同位置,其中含有细菌、真菌、藻类、原生动物和后生动物等微生物,这些微生物与填料表面结合并大量繁殖,从而形成生物膜(挂膜).大颗粒悬浮物易于被波纹状的孔隙拦截,孔隙率高(根据填料大小在82%～92.4%之间),过滤阻力小,可高效、顺畅地进行过滤.     

地下水固锰除铁工程设计

地下水固锰除铁工艺中在跌水曝气后过氧化问题一直是该工艺的关键内容,将跌水曝气池、滤池、反冲洗水池合建形成一体化固锰除铁单元,可以根据水量控制曝气强度,防止过曝气,稳定过滤水头,而且可以节约占地,减少滤池面积,并方便运行管理。     

Ammonia, iron and manganese removal from potable water using trickling filters

Pilot scale trickling filters were constructed and tested in order to study biological removal of ammonia, iron and manganese from potable water. The effect of the size of the support material on nitrification performance was studied extensively. The mean size of the gravel and hence, the specific surface area was found to be critical for optimal nitrification operation. A steady-state model developed in previous work was used to predict filter's performance. The model was very accurate only for the gravel size for which maximum nitrification rates were observed. The effect of the operational conditions on the physico-chemical and combined physico-chemical and biological iron oxidation was also studied. It was found that the contribution of biological oxidation is significant, increasing filter's efficiency by about 6% and reducing the required filter depth by about 40%. Manganese biological removal was studied using gravel with small mean diameter, thus providing high specific surface area. Feed concentrations up to 4.0 mg/l were treated sufficiently. Finally, experiments were performed to investigate the simultaneous removal of ammonia, iron and manganese. Experimental results showed that the combined, as well as the simultaneous removal of the aforementioned pollutants, can be achieved by single-step filtration.     

Removal of manganese from water supplies intended for human consumption: a case study

In the Volcano Etna area (Sicily) a substantial part of groundwater, used for potable purpose, has concentrations of metals (vanadium, iron and manganese) higher than the maximum contaminant levels (MCLs) set by European and National regulations (European Directive 98/83 and D.Lgs. 31/2001). Specifically, high levels of manganese, up to 1810 μg/l, significantly exceeding the maximum contaminant level (MCL = 50 μg/l), were detected in groundwaters currently used as drinking water supply upwelled from the Etna Volcano aquifer. The paper presents the results of the manganese removal process by potassium permanganate oxidation followed by flocculation, settling and filtration. Batch tests were carried out varying pH, oxidant doses and polyelectrolytes. Two different filters (35 μm and 0.45 μm mesh) were tested as a final step of the treatment. Significant removal (up to 95%) was achieved by addition of polyelectrolytes at pH 8.5, with a 0.5 stoichiometric dose of oxidant and final filtration through 35 μm mesh filter.     

Treatment of iron and manganese in simulated groundwater via ozone technology

This paper deals with experimental investigations related to removal of iron and manganese from simulated contaminated groundwater via ozone technology. Ozone as a powerful oxidizing agent, which was used in this study to oxidize iron and manganese converting ferrous ions (Fe²⁺) iron to ferric state (Fe³⁺) and (Mn²⁺) to (Mn⁴⁺) state, the oxidized salts will precipitate as ferric hydroxide and manganese oxide, that to reach the concentrations of these pollutants under their limit values in drinking water. The initial concentrations of (Fe²⁺) and (Mn²⁺) in synthetic water sample under study were 2.6 mg/l and 1 mg/l respectively. The effects of ozone dose concentration, operating temperature, and pH on the percentage removal of (Fe²⁺) and (Mn²⁺) have been discussed. For optimum removal of iron and manganese species the ozone dose has been noted as 3 mg/l at optimum temperature of 20 °C which improved removal of (Fe²⁺) and (Mn²⁺) to more than 96% and 83% respectively. The removal percentage of both metals was also affected by changing pH with the range of 5-12; where the maximum removal of iron and manganese was observed in pH (9-10). Experiments also studied the effects of coagulant type and bicarbonate concentration in raw water, as a result it was found that the optimum concentrations of coagulant was a mixture of 30 mg/l of aluminum sulfate with 10 mg/l of lime.     

Iron Behavior in the Ozonation and Filtration of Groundwater

In Finnish groundwater, the main substances that require treatment are iron and manganese. In addition to this, groundwaters are soft and acidic. Iron removal is usually relatively effective by oxidizing dissolved iron into an insoluble form, either by aeration or chemical oxidization and removing the formed precipitate by sand filtration. Sometimes, if the untreated water contains high amounts of organic matter, problems may arise for iron removal. In Finland, it is quite common that groundwater contains high levels of both iron and natural organic matter, mainly as humic substances. The groundwater of the Kukkala intake plant in Liminka has been found to be problematic, due to its high level of natural organic matter. This research studied the removal of iron from this water by means of oxidation with ozone and filtration. While the oxidation of iron by ozone was rapid, the precipitate particles formed were small, and thus could not be removed by sand and anthracite filtration, and the iron residue in the treated water was more than 2 mgL^?1. And while the filtration was able to remove iron well without the feed of ozone, the iron residue in the treated water was only 0.30 mgL^?1. In this case, iron was led to the filter in a bivalent dissolved form. So, the result of iron removal was the best when the sand/anthracite filter functioned largely as an adsorption filter.     

曝气生物滤池-超滤组合工艺处理高氨氮高有机物原水的效果

以重庆某水库水为对象,考察了曝气生物滤池-超滤组合工艺对高氨氮、高有机物原水中污染物的去除效果。结果表明:试验装置运行期间,进水COD_Mn平均值为7 mg/L,出水COD_Mn平均值为3.5 mg/L,COD_Mn平均去除率为50.0%;进水氨氮平均值为0.65 mg/L,出水氨氮平均值为0.12 mg/L,氨氮平均去除率为81.5%。组合工艺对COD_Mn和氨氮的平均去除率较曝气生物滤池分别提高了26.9%和11.4%,较常规絮凝-沉淀工艺分别提高了20.0%和58.5%,原水经曝气生物滤池-超滤组合工艺处理后,其氨氮、COD_Mn均满足《生活饮用水卫生标准》(GB 5749—2006)中的相关要求。