进水C/N对表面流—水平流人工湿地氮和COD去除效果的影响

通过模拟试验,研究在进水氮浓度不同条件下C/N对种植美人蕉的表面流—水平流人工湿地氮元素和COD去除能力的影响,并初步探讨其作用机理。结果表明:在营养生长期和开花期,低C/N有利于人工湿地系统中总氮和铵态氮的去除,C/N越高,硝态氮去除越彻底,而低C/N条件下,表面流—水平流人工湿地内的硝化作用限制了硝态氮的去除效果;对比2个生长期,各处理组总氮和硝态氮的去除能力相当,而开花期各处理组人工湿地铵态氮的去除能力高于营养生长期。C/N对人工湿地系统COD的去除效果的影响较少,2个生长期COD的去除效果相当,各处理组人工湿地系统COD的去除率约高于90%。随着停留时间的增加,人工湿地氮元素和COD的去除率均增加。对pH而言,湿地系统出水pH总体上先升高后趋于平稳,而氧化还原电位则先降低后升高最后趋于平稳,随C/N增加,出水pH降低,而氧化还原电位升高;营养生长期出水pH高于开花期,而氧化还原电位则呈相反表现。进水C/N和人工湿地系统共同影响着出水pH和氧化还原电位。     

亚铁对水平潜流人工湿地污染物去除能力的分层效应影响

通过模拟试验,考察并探讨不同浓度亚铁添加对水平潜流人工湿地中氮和COD去除能力的影响以及作用机理。结果表明:添加亚铁有利于水平潜流人工湿地各层中总氮、硝态氮和铵态氮的去除效果,而且添加亚铁浓度为50mg/L的人工湿地系统优于其他各处理组,但是过高的亚铁添加又限制了氮的去除效果,尤其是对下层铵态氮的去除能力有抑制作用,但是均高于对照组,而且亚铁添加影响了湿地系统这3种无机形态的氮分层效应。亚铁的添加促进试验初期人工湿地对COD的去除能力,在一定程度上影响了各层COD的去除效果。亚铁离子进入人工湿地后,系统中各层铁元素浓度迅速下降,但是由于铁元素的变价结构及其易水解特性,使得各处理系统出水pH先增加后趋于平稳,且下层pH低于上层和中层,同时也使得系统各层氧化还原电位(ORP)发生变化。亚铁添加促进了湿地系统中ORP的分层,却减缓了ORP的下降。     

不同碳氮比条件下4种可控因素对垂直流人工湿地总氮去除的影响

以模拟垂直流人工湿地为研究对象,采用正交试验法考查了在不同碳氮比（C/N）条件下,进水流量、水位高度、湿干比及运行周期4个可控因素对垂直流人工湿地脱氮的影响。结果表明,增加C/N可提高总氮去除效率,4个可控因子对污水总氮的去除有显著影响,进水量是总氮去除最重要的影响因素,干湿比的影响强度随着C/N的增大而增加,当C/N为1∶1和3∶1时,总氮的去除效果最优组合为：水位高度为50cm,湿干比为2∶1,周期为24h且进水流量为80cm·d-1;当C/N为5∶1时,总氮的去除效果最优组合为：水位高度为25cm,湿干比为1∶1,周期为24h且进水流量为80cm·d-1。     

退耕湿地典型植被群落土壤氮分布及储量特征

为阐明退耕湿地植被恢复对土壤氮素的影响,以黄河中游湿地河南武陟渠首段为研究对象,分析滩区耕地和退耕恢复区3种典型湿地植被群落土壤pH、有机质、总氮、硝态氮、铵态氮和氮储量的变化。研究结果表明,随着退耕恢复时间的增加,土壤pH呈下降趋势;土壤有机质、总氮总含量和氮储量呈逐渐增加趋势,分别由未恢复前的7.69~10.08g/kg,174.44~344.13mg/kg和0.07~0.09kg/m2增加到恢复1.5a后的15.83~29.53g/kg,739.13~1 076.99mg/kg和0.22~0.33kg/m2。恢复区土壤有机质、总氮总含量在空间上的变化表现为上层大于下层,土壤硝态氮含量均低于氨态氮含量。不同湿地植被土壤中总氮、有机质含量和氮储量存在显著差异(P0.05),其含量大小均依次为水蓼群落水烛群落芦苇群落。相关分析结果表明,研究区土壤中有机质含量与总氮之间存在极显著正相关关系(r=0.80;P0.01),铵态氮含量与有机质、总氮之间均存在极显著正相关关系(r=0.69,0.50;P0.01),硝态氮含量和有机质、总氮、铵态氮之间均存在一定正相关性,土壤pH与有机质和总氮之间均存在显著负相关关系(r=-0.49,-0.46;P0.05)。     

水稻土和菜田添加碳氮后的气态产物排放动态

【目的】动态连续监测添加碳氮底物后各气体产物—O2、 NO、 N2O、 CH4和N2的排放,对土壤碳氮转化过程和气体产生过程做更深入的理解,揭示不同土地利用方式典型红壤的温室气体产生机制。【方法】采集长江中游金井小流域不同土地利用方式稻田和菜地土壤为研究对象,利用全自动连续在线培养检测体系(Robot系统),通过两组试验分别研究土壤碳氮转化过程中各气体产物的动态变化。试验1采用菜地和稻田土壤进行好气培养,设置不施氮对照、 添加40 mg/kg铵态氮、 添加40 mg/kg铵态氮+1%硝化抑制剂、 添加40 mg/kg硝态氮、 添加40 mg/kg硝态氮+1%葡萄糖、 缺氧条件下添加40 mg/kg硝态氮+1%葡萄糖6个处理。试验2采用稻田土壤进行淹水培养,设不施氮对照、 添加40 mg/kg铵态氮、 添加40 mg/kg铵态氮+1%硝化抑制剂、 添加40 mg/kg铵态氮+1%秸秆、 缺氧条件下添加40 mg/kg铵态氮+1%的葡萄糖、 添加40 mg/kg硝态氮、 添加40 mg/kg硝态氮+1%葡萄糖、 缺氧条件下添加40 mg/kg硝态氮+1%葡萄糖8个处理。培养温度均为20℃,土壤水分含量为70% WFPS (土壤孔隙含水量),培养周期为15天。【结果】从菜地和稻田土壤不同碳氮添加处理气态产物及无机氮的动态变化可看出: 1)菜地土壤好气培养初期硝化作用产生了大量N2O; 受低碳和低含水量的限制,反硝化作用较弱。当提供充足碳源和厌氧条件,出现N2O和NO的大量排放。2)在好气稻田和淹水稻田培养过程中,反硝化作用是N2O产生的主要途径。3)稻田土壤中,提供充足碳源和厌氧条件,各气态产物出现的顺序依次是NO、 N2O和N2,与三种气体在反硝化链式反应过程中的生成顺序一致。淹水稻田加铵态氮和碳源处理N2为主要产物,添加硝态氮处理后,N2O成为主要气态产物。当土壤碳源充足时,反硝化过程进行彻底,反硝化产物以终产物(N2)为主。4)在稻田土壤出现厌氧或添加碳源条件下,均检测到大量CH4产生; 且在甲烷产生的同时,NO-3几乎消耗殆尽。【结论】金井小流域典型红壤菜地N2O主要来自于硝化作用,好气和淹水稻田N2O主要来源于反硝化作用; 当碳源充足和厌氧时,菜地及稻田反硝化作用增强; 反硝化产物组成、 产物累积量及出峰顺序与碳源和氧气浓度有关。     

外源氮对滨海围垦稻田土壤N2O还原速率的影响机制研究

滨海湿地位于海陆交错带,具有很高的生态价值;近百年来的人类活动深刻改变了湿地土壤的N2O排放通量。为探明外源氮对滨海围垦稻田土壤N2O还原潜力的影响,选取长江口崇明岛东滩芦苇湿地和围垦区不同围垦年限(19、27、51、86年)的稻田土壤为研究对象,添加不同形态外源氮后研究湿地土壤N2O还原速率的变化情况。结果表明,无氮添加条件下芦苇湿地土壤N2O还原速率最高,为36.6 μg·g-1·d-1,相比围垦19年稻田土壤提高了103%;添加硝态氮条件下围垦86年稻田土壤N2O还原速率最高,是围垦19年稻田土壤的3.9倍,添加铵态氮和硝态氮条件下稻田土壤N2O还原速率年增长率分别为0.37和0.69 μg·g-1·d-1·年-1,比无氮处理分别高出140%和343%。对于同一样地土壤而言,外源氮输入对其N2O还原速率的影响效应各异。其中,与无氮对照相比,添加铵态氮条件下芦苇湿地土壤的N2O还原速率降低了32%,而添加硝态氮条件下围垦86年稻田土壤的N2O还原速率增加了91%。相关性分析发现,稻田N2O还原速率与土壤有机碳、总氮呈显著正相关,而与电导率、SO42-呈显著负相关。因此,在围垦区水稻生产中,不同形态氮肥施用对稻田土壤的N2O还原过程产生重要的影响效应。     

寒冷地区多级垂直流人工湿地系统设计及氮磷去除效率

为了解决北方寒冷地区人工湿地冬季效率低、运行不稳定的问题,设计建设了两个多级垂直流人工湿地系统(multistage vertical-flow constructed wetlands,MVCWs),处理北京房山区居民生活污水,通过工程设计以及添加碳源强化系统脱氮效果,增加磷吸附基质等措施,提高系统稳定性和污染物的去除效率。研究结果表明,湿地系统Ⅰ化学需氧量(chemical oxygen demand,COD)的平均去除率为87.3%;总磷(total phosphorus,TP)的平均去除率为91.9%;总氮(total nitrogen,TN)的平均去除率为68.9%,能够全年稳定运行。湿地系统Ⅱ采取半间歇式运行方式,在0.5 m3/(m2·d)的水力负荷条件下,对COD、TN、TP的平均去除率分别为92.5%、53.8%、77.2%。湿地系统Ⅱ厌氧单元添加62 kg木块后,COD/TN从0.93上升到1.85,比添加31 kg木块单元对TN的去除率提高15.6%。木块作为厌氧阶段的外加碳源,有效促进了垂直流人工湿地系统对氮的去除。通过垂直流人工湿地多级合理的单元设计,在厌氧阶段添加碳源有利于反硝化脱氮以及添加吸附磷的基质,提高冬季没有植物参与时高效除氮、磷,有效地保证对各种污染物的去除效率。使该研究中的人工湿地系统能够全年稳定运行,该研究结果可为人工湿地在中国北方的推广应用提供参考。     

土壤辐照灭菌对土壤中铵态氮和硝态氮行为的影响

拟通过土壤辐照灭菌的方法,研究土壤微生物对硝态氮和铵态氮在土壤中的相互转化、固持及损失的影响,为提高作物氮肥利用率提供理论依据。采用土壤纯培养的方法,通过外源添加~(15)N标记铵态氮肥[(~(15)NH_4)_2SO_4]和硝态氮肥(Na~(15)NO_3),结合γ辐照灭菌的方法,培养30 d后,测定分析了灭菌和未灭菌土壤中总的、来自于肥料的和来自于土壤的铵态氮和硝态氮含量,并定量评价了肥料氮在土壤中的残留、固持和损失情况。结果表明:灭菌显著抑制铵态氮向硝态氮的转化,激发土壤铵态氮的释放,对铵态氮在土壤中的残留、固持和损失没有显著影响;灭菌对土壤硝态氮转化为铵态氮的过程没有影响,降低了硝态氮在土壤中的残留和固持,增加了硝态氮的损失;与外源添加硝态氮相比,外源添加铵态氮促进了土壤自身无机氮的释放,外源添加的铵态氮在土壤中残留低、固持高、损失高。因此,总体来看,灭菌有利于土壤铵态氮的积累,却降低土壤硝态氮的积累。虽然外源铵态氮较外源硝态氮更能激发土壤无机态氮的释放,并更易被土壤固持,但是铵态氮肥较硝态氮肥在土壤中残留少、损失多。     

人工湿地-电活性菌藻膜技术处理养猪废水中试试验

人工湿地由于具有运行成本低、维护简单等优点而被广泛应用于养殖废水处理。然而,人工湿地技术普遍存在污染物去除效率受温度影响大等问题。在该研究中,通过构建电活性菌藻生物膜来强化人工湿地系统,对养猪废水进行了自然温度下的处理效能与微生物群落研究,在室外开展了18个月试验,结果表明：电活性菌藻生物膜强化组在夏季化学需氧量、氨氮、硝态氮、总氮、总磷、亚硝态氮的去除率分别达到98.26%、97.96%、85.45%、95.07%、94.64%和85.45%。在冬季化学需氧量、氨氮、硝态氮、总氮、总磷、亚硝态氮的去除率分别达到96.10%、91.56%、75.29%、89.94%、92.12%和83.15%。具有良好低温适应性。强化组冬季化学需氧量、氨氮、硝态氮、总氮、总磷、亚硝态氮的出水浓度均满足《禽畜养殖业污染物排放标准》（GB18596—2001）。相比未构建电活性菌藻生物膜的对照组,以上污染物去除率均分别提高。电活性菌藻膜在冬夏季节的优势微生物均为Cyanobium、Shewanella、Azoarcus,群落结构稳定性高,有利于促进冬季污染物去除率,为提高系统污水处理可靠性提供了保障。     

降雨对不同土地利用类型土壤水氮变化特征的影响

以2018年6—10月降雨条件下园地、林地、荒草地、坡耕地和裸地的标准径流小区为研究对象,裸地为对照,通过研究降雨对园地、林地、荒草地、坡耕地和裸地的土壤含水率、总氮、硝态氮和铵态氮含量与土层深度和时间的变化特征,经野外试验数据统计分析,提出降雨对园地、林地、荒草地、坡耕地和裸地土壤含水率、总氮、硝态氮和铵态氮含量与土层深度和时间变化特征的影响。结果表明:降雨增加园地、林地、荒草地、坡耕地和裸地土壤含水率,加速土壤总氮、硝态氮和铵态氮水解转化硝化和反硝化速度,影响土壤含水率、总氮、硝态氮和铵态氮含量,降雨与土壤含水率、总氮、硝态氮、铵态氮呈显著相关性(P0.05)。降雨条件下园地、林地、荒草地、坡耕地和裸地的土壤含水率随土层深度增大而增大,土层深度100 cm处土壤含水率最大,分别为30.34%,27.67%,24.98%,24.03%和21.95%,总氮随土层深度增大呈先增大后减小,在土层深度为60 cm土壤总氮含量最大,分别为1.02,0.99,0.90,0.86,0.75 g/kg,硝态氮和铵态氮含量随土层深度增大而减小,在土层深度为100 cm硝态氮和铵态氮含量均最小,其中硝态氮含量分别为9.01,7.89,7.25,6.10,5.22 mg/kg,铵态氮含量分别为9.41,9.14,6.40,5.38,4.37 mg/kg。土壤含水率随时间的延长先减小后增大又减小,呈正余弦变化趋势,8月土壤含水率最大,分别为22.97%,22.01%,19.87%,19.03%和17.98%,总氮随时间的延长先增大后减小,8月总氮最大,分别为1.09,1.01,0.94,0.84,0.76 g/kg,硝态氮和铵态氮含量随时间的延长而逐渐减少,6月硝态氮和铵态氮含量均最大,其中硝态氮含量分别为13.40,12.37,11.20,10.39,8.67 mg/kg,铵态氮含量分别为18.89,17.02,14.54,12.02,8.36 mg/kg。不同土地利用类型土壤含水率、总氮、硝态氮和铵态氮平均值与土层深度和时间关系由大到小依次为园地、林地、荒草地、坡耕地和裸地,研究结果为农田土壤水肥流失控制和养分利用提供理论技术支持。     

不同氮肥种类和亏缺灌溉对切花百合品质的影响

【目的】 氮素营养和土壤水分是影响百合切花生长和品质的重要因素。本研究进行了不同氮肥配比和灌溉量对百合生长、切花期、切花观赏品质、瓶插寿命和瓶插期间叶片和花被片生理指标的影响,以期为百合切花生产的水氮管理提供科学依据。【方法】 以东方百合‘索邦’为材料,在施氮（N）量相同情况下,盆栽试验设5种氮素处理,即单施尿素,单施铵态氮肥,单施硝态氮肥,铵态氮:硝态氮（50%:50%）、尿素氮:硝态氮（50%:50%）;2个灌水水平,即正常灌溉（苗期土壤含水量保持在60%~70%θ_f和现蕾期后70%~80%θ_f,θ_f是田间持水量）和亏缺灌溉（苗期土壤含水量保持在50%~60%θ_f和现蕾期后60%~70%θ_f）。在百合停止生长后,测定了株高和茎粗、花朵数量、花径、瓶插寿命,开花第7天和第14天百合叶片和花被片中可溶性糖、可溶性蛋白和丙二醛含量。【结果】 铵态氮肥与硝态氮肥配施处理百合株高最高,花朵数量最多,切花瓶插寿命最长,开花第7天和第14天叶片和花被片中可溶性糖和可溶性蛋白含量较高,并缓解叶片和花被片中的丙二醛积累。与正常灌溉相比,亏缺灌溉对百合株高、花朵数量、花径、切花瓶插寿命以及开花后叶片和花被片中的丙二醛、可溶性糖和可溶性蛋含量的影响因不同氮肥处理而异。在两种灌水水平下,单施尿素、尿素和硝态氮肥配施以及铵态氮肥和硝态氮肥配施处理切花期分别为100 d、90 d和85~86 d。在正常灌溉条件下,单施铵态氮肥和单施硝态氮肥切花期差异不大,为85~86 d;而在亏缺灌溉条件下,单施硝态氮肥切花期为91 d,而单施铵态氮肥为87.5 d。【结论】 硝态氮肥和铵态氮肥配施可以提高百合株高和花朵数量,缩短百合切花期,延长切花瓶插寿命,从而提高百合切花品质。而亏缺灌溉对百合切花质量的影响因不同氮肥处理而异。     

Influences of past application rates of nitrogen and a catch crop on soil microbial communities between an intensive rotation

The aim of this study was to investigate influences of six-year past application rates of nitrogen and a catch crop, sweet corn (Zea mays L. ssp. Saccharata Sturt), on soil microbial community and diversity in a greenhouse-based intensive vegetable soil in eastern China. Soil electrical conductivity, pH, mineral nitrogen, phospholipid fatty acids (PLFA) profiles and carbon source utilization patterns under five annually past nitrogen rates (0, 348, 522, 696 and 870?kg?nitrogen?ha^?1) were evaluated after the establishment of sweet corn during 1–1.5-month fallow period over three-year tomato/cucumber/celery rotations. The past nitrogen application rates exerted significant effects on soil electrical conductivity, pH, nitrate-nitrogen, ammonium-nitrogen and carbon source utilization patterns, but not on PLFAs profiles. The sweet corn had a significant effect on soil chemical properties, total and actinobacterial PLFAs, but not on carbon source utilization patterns. Soil electrical conductivity, nitrate-nitrogen and the total PLFAs decreased whilst soil organic carbon, pH and the actinobacterial PLFAs increased after the establishment of sweet corn. Soil microbial functional diversity from carbon source utilization patterns and actinobacterial PLFAs were greatest after the establishment of sweet corn at a 60% of the conventional nitrogen rate (i.e. 522?kg?nitrogen?ha^?1). Soil electrical conductivity and ammonium-nitrogen were two key factors to determine carbon source utilization patterns, whilst soil pH was the key factor to determine PLFAs profiles. A combination of the catch crop sweet corn during summer fallow and a 60% of the conventional nitrogen rate is a sustainable pathway of utilizing greenhouse-based intensive vegetable soils in eastern China.     

菌剂挂膜3D-RBC联合BCO工艺处理养猪沼液废水

针对养猪沼液废水寡营养、高氨氮的水质特征,该研究采用耐高氨氮、适应贫营养生长的异养硝化-好氧反硝化（Heterotrophic Nitrification-Aerobic Denitrification,以下简称HN-AD）菌挂膜启动三维结构生物转盘+生物接触氧化反应器（3D-RBC+BCO）组合工艺对沼液进行处理。该文研究了3D-RBC+BCO组合工艺在真实沼液条件下的启动过程及污染物去除效果,重点考察了溶解氧（Dissolved Oxygen,DO）浓度和C/N比2个关键因素对组合工艺污染物去除效果的影响。同时,借助高通量测序技术对DO和C/N比优化过程中微生物群落结构的变化规律进行解析。结果表明：在真实沼液条件下,采用HN-AD菌剂挂膜启动方法,仅用12和18 d就分别完成3D-RBC和BCO反应器的挂膜启动,同时组合工艺对COD、NH4+-N和TN的去除率分别稳定在94.8%、95.7%和80.1%,出水优于城镇污水厂排放一级B标准。在对3D-RBC反应器DO和C/N比的优化过程中,增设底曝后COD、NH4+-N和TN等指标的去除率分别降低了25.4%、15.4%和15.5%。高通量测序结果显示,增加底曝后3D-RBC盘片生物膜中微生物菌属的数量小幅下降,但HN-AD优势菌属的种类与丰度显著降低,导致脱氮效率下降;贫营养型Acinetobacter、Pseudomonas菌属是3D-RBC可以对真实沼液高效脱氮的关键,提高C/N比会显著降低其丰度,进而影响脱氮效果。     

Nutrient Removal in Pilot-Scale Constructed Wetlands Treating Eutrophic River Water: Assessment of Plants, Intermittent Artificial Aeration and Polyhedron Hollow Polypropylene Balls

Seven experimental pilot-scale subsurface vertical-flow constructed wetlands were designed to assess the effect of plants [Typha latifolia L. (cattail)], intermittent artificial aeration and the use of polyhedron hollow polypropylene balls (PHPB) as part of the wetland substrate on nutrient removal from eutrophic Jinhe River water in Tianjin, China. During the entire running period, observations indicated that plants played a negligible role in chemical oxygen demand (COD) removal but significantly enhanced ammonia–nitrogen (NH₄–N), nitrate–nitrogen (NO₃–N) total nitrogen (TN), soluble reactive phosphorus (SRP) and total phosphorus (TP) removal. The introduction of intermittent artificial aeration and the presence of PHPB could both improve COD, NH₄–N, TN, SRP and TP removal. Furthermore, aerated wetlands containing PHPB performed best; the following improvements were noted: 10.38 g COD/m² day, 1.34 g NH₄–N/m² day, 1.04 g TN/m² day, 0.07 g SRP/m² day and 0.07 g TP/m² day removal, if compared to non-aerated wetlands without PHPB being presented.     

Effects of Vegetation, Season and Temperature on the Removal of Pollutants in Experimental Floating Treatment Wetlands

The research and interest towards the use of constructed floating wetlands for (waste)water treatment is emerging as more treatment opportunities are marked out, and the technique is applied more often. To evaluate the effect of a floating macrophyte mat and the influence of temperature and season on physico-chemical changes and removal, two constructed floating wetlands (CFWs), including a floating macrophyte mat, and a control, without emergent vegetation, were built. Raw domestic wastewater from a wastewater treatment plant was added on day 0. Removal of total nitrogen, NH₄–N, NO₃–N, P, chemical oxygen demand (COD), total organic carbon and heavy metals (Cu, Fe, Mn, Ni, Pb and Zn) was studied during 17 batch-fed testing periods with a retention time of 11 days (February–March 2007 and August 2007–September 2008). In general, the CFWs performed better than the control. Average removal efficiencies for NH₄–N, total nitrogen, P and COD were respectively 35%, 42%, 22% and 53% for the CFWs, and 3%, 15%, 6% and 33% for the control. The pH was significantly lower in the CFWs (7.08?±?0.21) than in the control (7.48?±?0.26) after 11 days. The removal efficiencies of NH₄–N, total nitrogen and COD were significantly higher in the CFWs as the presence of the floating macrophyte mat influenced positively their removal. Total nitrogen, NH₄–N and P removal was significantly influenced by temperature with the highest removal between 5°C and 15°C. At lower and higher temperatures, removal relapsed. In general, temperature seemed to be the steering factor rather than season. The presence of the floating macrophyte mat restrained the increase of the water temperature when air temperature was >15°C. Although the mat hampered oxygen diffusion from the air towards the water column, the redox potential measured in the rootmat was higher than the value obtained in the control at the same depth, indicating that the release of oxygen from the roots could stimulate oxygen consuming reactions within the root mat, and root oxygen release was higher than oxygen diffusion from the air.     

Attenuation of Bulk Organic Matter, Nutrients (N and P), and Pathogen Indicators During Soil Passage: Effect of Temperature and Redox Conditions in Simulated Soil Aquifer Treatment (SAT)

Soil aquifer treatment (SAT) is a cost-effective natural wastewater treatment and reuse technology. It is an environmentally friendly technology that does not require chemical usage and is applicable to both developing and developed countries. However, the presence of organic matter, nutrients, and pathogens poses a major health threat to the population exposed to partially treated wastewater or reclaimed water through SAT. Laboratory-based soil column and batch experiments simulating SAT were conducted to examine the influence of temperature variation and oxidation?Creduction (redox) conditions on removal of bulk organic matter, nutrients, and indicator microorganisms using primary effluent. While an average dissolved organic carbon (DOC) removal of 17.7?% was achieved in soil columns at 5?°C, removal at higher temperatures increased by 10?% increments with increase in temperature by 5?°C over the range of 15 to 25?°C. Furthermore, soil column and batch experiments conducted under different redox conditions revealed higher DOC removal in aerobic (oxic) experiments compared to anoxic experiments. Aerobic soil columns exhibited DOC removal 15?% higher than that achieved in the anoxic columns, while aerobic batch showed DOC removal 7.8?% higher than the corresponding anoxic batch experiments. Ammonium-nitrogen removal greater than 99?% was observed at 20 and 25?°C, while 89.7?% was removed at 15?°C, but the removal substantially decreased to 8.8?% at 5?°C. While ammonium-nitrogen was attenuated by 99.9?% in aerobic batch reactors carried out at room temperature, anoxic experiments under similar conditions revealed 12.1?% ammonium-nitrogen reduction, corresponding to increase in nitrate-nitrogen and decrease in sulfate concentration.     

反硝化脱氮除磷-侧流磷回收工艺效能

为了调查反硝化同步脱氮除磷-侧流磷回收新工艺的工艺效能,该试验在该工艺稳定运行条件下评价其污染物(化学需氧量、总氮、NH+4-N和PO3-4-P)去除能力和磷回收能力。结果表明:当进水中化学需氧量、总氮、NH+4-N和PO3-4-P的质量浓度为239.2~259.5、39.6~43.8、38.2~41.8和8.72~11.40 mg/L,出水中相应的质量浓度分别为15.2~21.6、8.5~9.6、3.6~4.7和0.31~0.49 mg/L,满足国家《城镇污水处理厂污染物排放标准》(GB18918-2002)一级A排放标准;COD主要在厌氧池被去除,NH+4-N主要在好氧硝化池中去除;污水中磷的去除主要由诱导结晶磷回收和生物除磷两部分组成;整个工艺中,磷去除效率为95.9%,其中诱导结晶磷去除率占总去除效率的71.5%,表明该工艺具有较大磷回收潜力。此外,后置曝气池可对出水中COD、NH+4-N和PO3-4-P浓度起着把关作用,有助于提高出水水质。     

Treatment Efiiciencies of Constructed Wetlands for Eutrophic Landscape River Water

The efficiencies of two types of constructed wetlands for the treatment of low-concentration polluted eutrophic landscape river water were studied in the western section of the Qingyuan River at the Minhang campus of Shanghai Jiaotong University. The first wetland was a single-stage system using gravel as a filtration medium, and the second was a three- stage system filled with combinations of gravel, zeolite, and fly ash. Results from parallel operations of the wetlands showed that the three-stage constructed wetland could remove organics, nitrogen, and phosphorus successfully. At the same time, it could also decrease ammoniacal odour in the effluent. Compared to the single-stage constructed wetland, it had better nutrient removal efficiencies with a higher removal of 19.37%-65.27% for total phosphorus （TP） and 21.56%- 62.94% for total nitrogen （TN）, respectively, during the operation period of 14 weeks. In terms of removal of chemical oxygen demand （COD）, turbidity, and blue-green algae, these two wetland systems had equivalent performances. It was also found that in the western section of the test river, in which the two constructed wetlands were located, the water quality was much better than that in the eastern and middle sections without constructed wetland because COD, TN, and TP were all in a relatively lower level and the eutrophication could be prevented completely in the western section.     

猪场废水厌氧消化液后处理技术研究及工程应用

猪场废水经过厌氧消化后，可生化性变差，BOD₅/COD仅为0.19，并且碳、氮倒置，比例严重失调，给后续好氧处理带来很大困难。采用序批式活性污泥法(SBR)工艺直接处理厌氧消化液，污染物的去除效果很差，COD仅去除8.31%，NH₃-N去除78.7％。通过改善厌氧消化液的可生化性和培养高效脱氮菌种等措施，COD、NH₃-N去除率改善显著，COD、BOD₅与SS的去除分别达到89.6%～93.4%、97.9%，95.6%，特别是对NH₃-N，达到了99%以上去除效率。将实验室结果应用于实际工程，也取得了好的效果，工程上SBR系统对猪场废水厌氧消化液的COD去除90%左右，出水COD基本上在300 mg/L以下。NH₃-N去除率大于99%，出水NH₃-N小于10 mg/L。BOD₅去除率大于98%，出水BOD₅小于20 mg/L。TN去除率大于90%。