复合生物技术在城市河流污染修复中的应用

在南方某污染河流强制污染修复试验中,采用人工曝气与投加复合生物酶相结合的技术进行底泥消减,再使用梅花式菌剂接种法将菌剂与生物促生剂接种至水体及底泥中。接种后2 d内因接种操作扰动及生物促生剂含大量氮、磷元素使各水质指标呈上升趋势,接种第3 d起COD、TP、NH_3-N浓度迅速下降,水质得到改善;第8 d左右COD、TP、NH3-N去除率达到最高,投菌后10 d内DO平均浓度上升50%,COD、TP、NH3-N平均去除率分别在45%、40%、40%以上。结果表明:采用复合生物技术治理城市污染河流,可以初步消除河流黑臭、改善河流水质、恢复河流自净能力。     

生物滤沟处理景观水体试验研究

提出将传统的砂石过滤与湿地塘床相结合的组合处理工艺———生物滤沟 ,并对其在常温下处理受污染城市景观水体的性能进行试验研究。试验结果表明 ,生物滤沟采用多级跌水曝气方式能有效地控制出水的嗅味、氨氮值和提高有机物的去除效果     

锁磷剂微生物菌剂复合技术用于富营养水体治理的研究

北方特大缺水城市景观河道由于水资源短缺,河道用水置换次数少,河道水体自净能力低等原因,水体富营养化现象严重。采用新型除磷药剂——锁磷剂和微生物菌剂复合技术对河道水体进行水质净化试验。通过考察复合菌剂脱氮和降低COD的效果,来确定适宜的微生物投加浓度和验证复合技术的使用方式。     

锁磷剂-微生物菌剂复合技术应用于富营养水体治理的研究

北方特大缺水城市景观河道由于水资源短缺,河道用水置换次数少,河道水体自净能力低等原因,水体富营养化现象严重.采用新型除磷药剂--锁磷剂和微生物菌剂复合技术对河道水体进行水质净化试验.通过考察复合茵剂脱氮和降低COD的效果,来确定适宜的微生物投加浓度和验证复合技术的使用方式.     

有效微生物菌剂处理淀粉糖废水的试验研究

本试验以有效微生物菌剂为试验材料,以淀粉糖废水为供试样品,通过有效微生物菌剂作用测定淀粉糖废水好氧和厌氧条件下的pH、悬浮物含量(SS)、臭阈值、氨氮含量、化学需氧量(COD)等指标参数,确定该微生物菌剂废水处理最佳菌浓度及处理时间等条件。结果表明:好氧条件下,处理时间为5天,有效微生物菌剂接种量V菌剂/V废水为1/2 500时,废水中的COD由1074mg/L降至165mg/L、氨氮含量由9.30mg/L降至1.63mg/L。对COD、氨氮的最高去除率分别为84%、85.3%。     

景观水体富营养化与藻类过度生长控制技术的应用研究

针对景观河道水体自净能力差、富营养化现象严重、藻类过度生长等现状,课题组通过新型微生物复合菌剂、增强型锁磷剂的研制,对微生物、化学、水生植物复合净化技术进行集成,开展了水质净化及控制的原位修复技术研究,分为小试试验、生产性试验和示范工程三个阶段,实现了Ⅴ类水体的控制目标,复合技术通过兼顾三种技术的空间和时间效果,取长补短,实现水体整体生态系统的恢复,为景观湖泊、河道的治理提供了新的途径。     

曝气复氧对华南农村重污染河道底泥氮磷的作用机制研究

以华南农村的重污染河道水体底泥为试验对象,利用实验室模拟方法研究不同曝气复氧方式对水体氮磷素迁移与转化的影响。结果表明:1环境溶解氧水平的变化对底泥氮磷的输出和转化途径产生较大的影响;2静置低溶解氧/厌氧条件下,氨氮、总氮的释放质量浓度呈逐渐线型上升的趋势,总磷的释放质量浓度保持相对稳定不断释放;3相对静置实验组,曝气复氧条件使底泥氨氮输出最大质量浓度经一定时间下降到相对稳定的较低质量浓度释放状态,输出氨氮的转化周期缩短,总氮保持相对稳定的较高质量浓度释放趋势,总磷保持相对稳定的较低质量浓度释放状态;4对底泥曝气有助于水体溶解氧的恢复,可明显提高除氮磷效果,并能有效抑制底泥氮磷的再次释放。因此,合理地利用曝气复氧技术有助于河流环境的修复。     

除氮菌剂强化碳纤维的挂膜与脱氮效果

碳纤维作为生物膜载体具有一定脱氮能力,但存在自然挂膜周期较长、挂膜初期水质净化能力较差等问题.为提高碳纤维的挂膜与脱氮效果,采用除氮菌剂人工强化碳纤维挂膜,探究除氮菌剂对碳纤维固载微生物膜的强化作用,并查明挂膜成熟后碳纤维的脱氮性能.结果表明,除氮菌剂可显著强化碳纤维的挂膜效果,强化挂膜组碳纤维上的微生物量和微生物碳源...     

微生态菌剂直投技术原位修复微污染水源水的试验研究

应用微生态菌剂直投技术处理城市微污染水源水体是控制季节性水质污染和水体富营养化的重要方法。采用实验室模拟的方法,研究了筛选制备的生态菌剂在自然条件下不同投加量对水质净化效果的影响。试验进行了32d,结果表明,微生态菌剂原位直投技术用于水源水质的原位改善是可行有效的,对水中主要污染物指标及其去除率分别可达到:氨氮100%、硝态氮76.2%、总氮80.9%、总磷90%、TOC 67.6%和CODMn40.6%;微生态菌剂可与水体的土著菌种叠加形成稳定的生态位,充分发挥了同步硝化反硝化作用。     

给水生物处理工艺微生物特性研究

通过分析曝气生物滤池、生物活性炭滤池内微生物优势菌种、生物膜结构、生物膜量等特性,结合不同滤池微生物生长特点探讨不同类型生物滤池的挂膜特性以及对氨氮、亚硝酸盐氮和有机物的去除效果表现差异的原因;此外,通过进行生物活性炭滤池出水微生物菌种鉴定,分析经常规氯消毒后水质微生物安全性.试验结果表明,对炭滤出水采用次氯酸钠消毒,杀菌率达99.98%以上,但残留菌中检出有条件致病菌,需进一步研究其影响和对策.     

复合酶制剂处理城市景观水体的试验研究

采用新型复合酶制剂(BZ剂)处理城市受污染景观水体。研究结果表明:该制剂的使用对COD、NH3-N、TP等有明显的净化效果。在本试验条件下,BZ剂投加量为0.4 mg/(L.d)时,CODCr、NH3-N、TP的最终去除效果最好,分别达到25.0%7、7.6%2、6.1%;相同投加量条件下,水质净化效果不曝气优于曝气状况。     

曝气对富营养化景观水体藻类群落结构的影响

采用微宇宙培养法,模拟研究了不同曝气方式(底泥曝气、水曝气)对富营养化景观水体中浮游藻类群落结构的影响及影响因子。结果表明:水曝气使得水体溶解氧(DO)急剧增加,从而促进了水体藻类的生长,优势藻种由绿藻门急剧迁移到黄藻门的黄丝藻属;由于泥曝气对底泥中P释放的抑制作用,及浊度增加导致占藻类主要成分的蓝藻门藻类的不断消亡,而明显的抑制了藻类的生长,优势藻种也由绿藻门迁移到硅藻门。因此,在景观水处理技术中加入人工曝气时,应采用泥曝气的方式。     

碳素纤维生态草协同微生物菌剂净化黑臭水体研究

为解决黑臭水体治理投加菌剂易随水流飘散的问题，本文利用碳素纤维生态草对微生物菌剂固定挂膜，并通过原位围隔试验，探究微生物菌剂联合碳素纤维生态草处理黑臭水体的效果。试验结果表明:协同处理组的COD、浊度、TN、NH+4-N、TP的削减率分别为85.8%、75.2%、86.3%、90.8%、53%，DO从0.15mg/L恢复至5.8mg/L，水质状况显著改善。与单挂生态草试验组相比，协同处理组的成膜时间缩短3～5d，膜增重显著，生物膜形态较好;协同处理组水体环境微生物多样性增加，乳酸杆菌(Lactobacillus)、丝状菌(Filamentousbacteria)等益生菌在水体中出现，霍乱弧菌(Vibriocholerae)、幽门螺杆菌(Helicobacterpylori)等致病菌大量减少。试验证明，生态草协同微生物菌剂可加速黑臭水体净化，促进水生态稳定。     

Sources and scales of near-bottom turbulent mixing in large meromictic Lake Iseo

Mixing dynamics in the bottom boundary layer (BBL) of lakes is of primary importance for mediating mass and heat fluxes across the upper sediment. In lakes with depth of several hundred meters, the BBL mixing is often suggested to be low; however, quantitative information from these depths is extremely rare. We assessed the mixing conditions in the BBL of Lake Iseo, a 256 m deep, meromictic Italian lake, where anoxia and accumulation of phosphorus is a major issue. High-resolution temperature and currents measurements demonstrated regular development of turbulence at 220 m depth, with dissipation rates of the turbulent kinetic energy up to 10⁻⁷ W kg⁻¹, characteristic of a shear boundary layer. Analysis of temperature and oxygen dynamics revealed a direct link between the turbulence intensification in the BBL and the passage of a 90-h period basin-scale internal wave. This slow oscillatory motion was attributed to lake-wide internal waves of second vertical mode, whose effect in the upper part of the water column was much less profound. The wave passages were able to increase hypolimnetic velocities above 1 cm s⁻¹, to produce thermal instability across the BBL and to significantly enhance turbulent mixing in the deepest waters. During periods of high velocity bursts, the chemical stratification in the BBL was effectively eroded while direct sediment resuspension was unlikely. The new results reveal the turbulent character of the bottom boundary mixing in deep lakes, highlighting the direct link to wind-driven motions and important effects on the water–sediment exchange of solutes.     

Enhancement of oxygen transfer and nitrogen removal in a membrane separation bioreactor for domestic wastewater treatment.

Biological nitrogen removal in a membrane separation bioreactor developed for on-site domestic wastewater treatment was investigated. The bioreactor employed hollow fiber membrane modules for solid-liquid separation so that the biomass could be completely retained within the system. Intermittent aeration was supplied with 90 minutes on and off cycle to achieve nitrification and denitrification reaction for nitrogen removal. High COD and nitrogen removal of more than 90% were achieved under a moderate temperature of 25 degrees C. As the temperature was stepwise decreased from 25 to 5 degrees C, COD removal in the system could be constantly maintained while nitrogen removal was deteriorated. Nevertheless, increasing aeration supply could enhance nitrification at low temperature with benefit from complete retention of nitrifying bacteria within the system by membrane separation. At low operating temperature range of 5 degrees C, nitrogen removal could be recovered to more than 85%. A mathematical model considering diffusion resistance of limiting substrate into the bio-particle is applied to describe nitrogen removal in a membrane separation bioreactor. The simulation suggested that limitation of the oxygen supply was the major cause of inhibition of nitrification during temperature decrease. Nevertheless, increasing aeration could promote oxygen diffusion into the bio-particle. Sufficient oxygen was supplied to the nitrifying bacteria and the nitrification could proceed. In the membrane separation bioreactor, biomass concentration under low temperature operation was allowed to increase by 2-3 times of that of moderate temperature to compensate for the loss of bacterial activities so that the temperature effect was masked.     

藻华聚积及污水入流对太湖上下层水体营养盐含量的影响

通过采集太湖水体鲜藻和入湖区混合常见污水,应用再悬浮发生装置,室内模拟有底泥参与的不同藻类聚积和不同CODCr含量污水进入条件下,太湖西北竺山湖区水质上下层水体中SS,NH3-N及PO43-质量浓度的变化过程。分析结果表明:在7 d的常见风浪模拟环境中,无论加入藻类还是加入污水,太湖上下层水体中SS质量浓度均呈下降趋势,表明颗粒物有向水底沉降的可能;水体中的NH3-N和PO43-质量浓度并未因藻量增加而上升,反映出鲜藻此时对水体中的N和P呈吸收作用;污水添加量的增大则使试验水柱中NH3-N和PO43-质量浓度上升,并大致随时间的增加呈逐步上升的趋势。     

小浪底水库下游浮游生物及细菌群落对水沙调控的响应规律

浮游动物、浮游植物和细菌群落广泛分布于河流生态系统,发挥着初级生产者、初级消费者和分解者的重要作用,对于环境条件的波动较为敏感。本文于2018—2019年黄河小浪底水库调水调沙前、中、后期对下游河流进行了调查采样,得出水环境因子、浮游生物与细菌群落的定量结果,以明确在不同调水调沙阶段下游河流水环境因子,浮游生物和细菌群落的演变规律及相互作用。通过结构方程模型(SEM)和基于距离的冗余分析(dbRDA)、分别明确了调水调沙影响下浮游生物以及细菌群落对水环境因子的响应规律。结果表明,调水调沙不同阶段下,浮游植物、浮游动物和细菌对于环境因子的响应方式具有较大的差异,溶解氧(在调水调沙前影响系数最大,为0.86)、温度(在调水调沙期间影响系数最大,为0.76),以及电导率(调水调沙后影响系数最大,为0.82)等环境因子对浮游生物的生物量影响最明显,而溶解氧(在调水调沙前)和叶绿素a(调水调沙期间至调水调沙后)对于细菌群落的影响最大。此外,调水调沙过程改变了浮游生物群落内部关系,削弱了浮游动物对浮游植物的捕食,同时也使得悬浮和沉积状态的细菌群落在样点之间的差异性增大。本研究明确了浮游生物及细菌群落在水沙调控不同阶段下对水环境因子的响应规律,对下游河流生态修复具有一定的理论意义。     

A mechanistic model for estimating bacteria levels in stormwater ponds

This paper presents a three-dimensional CFD based hydro-environmental model that simulates fate and transport of bacteria in water bodies. The model numerically solves unsteady incompressible Reynolds-Averaged Navier-Stokes equations on a structured grid. Free-floating and particle-attached bacteria were modelled separately regarding both fate and transport. Therefore, a sediment transport model was integrated into the main model in order to model particle-attached bacteria transport. In addition, Volume of Fluid approach was implemented to capture the water surface movements. Wind effect was also considered in the modelling using shear stress on the water surface. Since stormwater reuse is the source of some public health concerns, a stormwater pond was chosen as the test case for the model. The model was applied to simulate the distribution of bacterial indicator organisms in the Inverness Stormwater Pond in Calgary, Alberta, which is a large T-shaped pond with several inlets and outlets. The bacteria distribution in the pond was simulated for three rain events that occurred in the area. In six locations of the pond the modelled bacteria distribution was compared to collected data using non-dimensional bacteria concentrations. The comparison showed good agreement and indicated that the middle of the pond, close to the surface had the lowest levels of bacteria and thus, was considered the optimal location for withdrawal for reusing pond water. Furthermore, planting a tree barrier on the north bank of the West wing of the pond was shown to mitigate bacteria transport away from the inlets into the pond body and substantially decrease the risk of contamination at the optimal water withdrawal location.     

里运河底泥COD和NH3-N空间分布及对水质的影响

通过对里运河底泥中污染物质的含量分析,阐述了不同深度底泥中COD和NH3-N的空间分布特征,结果发现城区段底泥中COD和NH3-N的含量约为非城区段的2倍,表层(0~30 cm)和次表层(30~60 cm)底泥污染较深层(150~210 cm)污染严重,0~60 cm底泥中的COD和NH3-N平均含量分别是深层底泥COD和NH3-N的2.5和2.1倍。同时通过对表层底泥和对应断面水质的比较分析,得出了表层底泥中COD和NH3-N的含量与水质有较好的相关性(R=0.76,n=12),说明底泥中污染物质的释放在一定程度上已经影响了里运河的水质。