炼油废水处理设施的工艺改进

针对炼油废水处理设施运行过程中存在的问题，采取了相应的改进措施；在气浮池中，取消多孔集水管，增设导水集泥斜板，将隔墙斜置，改顺水流刮渣为逆水流刮渣；在曝气沉淀池中，改池底中央进水为沿回流缝多点进水，改周边集水槽出水为径向集水槽出水；将活性炭回转再生炉改造为立式移动床。运行表明，改造取得了满意的效果。并从设计，运行控制参数的改进以及流体力学的基础理论等方面进行了论述。     

污水生物脱氮除磷中关键水质参数相关性分析

目前,大部分进行提标改造的污水处理厂都存在着忽略进水水质构成及变化的问题,导致后期工艺运行调整难、运行能耗高,影响出水稳定达标。运用SPSS软件包,分析了辽宁省某污水处理厂进水水质与出水TN、TP的相关性。结果表明,进水BOD_5/TN与出水TN中度负相关;进水BOD_5/TP与出水TP低度负相关;进水SS/BOD_5与出水TN基本不相关;进水BOD_5/COD与出水TP相关程度弱。这对现有污水处理厂的提标改造有一定的借鉴作用。     

SBR工艺处理糠醛废水研究

将糠醛厂塔底废水与其他生产废水混合,利用SBR工艺进行处理,研究了运行工况、污泥负荷和进水pH等对处理效果的影响.结果表明,反应操作灵活;适宜运行参数为pH 6～8,进水10 min,搅拌100 min,曝气120 min,沉淀120 min,出水10min;当进水COD≤950 mg/L,日污泥负荷MCOD/MMLSS=0.346时,出水COD＜100 mg/L.     

间歇式运行对人工湿地处理富营养化湖水的影响

针对五里湖富营养化水体,进行了中试规模人工湿地间歇式运行与连续式运行处理效果的比较研究,现场试验采用0.8 m3/m2·d的水力负荷.研究表明,采用间歇进水方式增强了人工湿地的复氧能力,出水溶解氧(DO)含量为2.6～4.5 mg/L,较连续进水方式平均提高了51.06%.间歇式进水对TN和NH4 -N的去除影响较大,与连续进水方式相比去除率分别提高了51.5%和30.5%;而对NO3-N、TP和CODMn的去除影响较小.采用间歇式运行TN的出水浓度较连续式运行稳定,受季节变化和进水浓度的影响较小,出水浓度＜2 mg/L;而间歇式运行对TP和CODMn出水浓度的稳定性影响不大.     

同步进出水SBR设备最佳进水方式流态模拟

借助流体计算软件Fluent对某同步进出水SBR设备4种不同进水位置以及3种进水孔排布分别进行流态模拟,根据模拟结果得到最佳的进水方式;同时在该进水方式下对进水流量为0.5、0.7、1.0、1.3和1.5 m3/h时反应器内的流态分布情况进行了数值模拟,最后通过示踪剂实验与模拟结果对比验证。对于实验用SBR(长×宽×高为2 m×2 m×1.2m),进水流量1.0 m3/h是最佳进水流量,此时反应器内流态稳定,进水区域主要分布于反应器中下部以及远离堰口的池壁附近,死水区面积较小,冲击负荷适中,进水对出水水质影响较小;当进水流量小于1.0 m3/h时,进水主要分布于反应器池底,对角线方向以及远离进水端池壁附近3个区域且彼此相对独立,池内死水区面积较大;当进水流量大于1.0 m3/h时,进水冲击负荷过大,迅速形成短流,影响出水水质。     

啤酒废水常温厌氧消化启动及运行实验

采用自行设计的复合式厌氧反应器在常温下对啤酒废水进行了厌氧发酵产沼气的实验研究,将进水COD控制在5 000 mg/L左右,采取逐步缩短HRT的方法来提高进水有机负荷,结果表明,启动运行41 d之后,产气量上升速度加快,反应器成功启动运行;在稳定运行过程中,随着负荷的升高,产气量呈阶梯式渐次上升,COD去除率保持在90%以上,出水pH值维持在7.0左右,TSS去除率达到60%以上,出水水质较好,说明该反应器具有较好的厌氧消化处理有机废水的能力。     

微氧条件下厌氧折流板反应器运行特性研究

对厌氧折流板反应器（anaerobic baffled reactor,ABR)在微氧条件下的运行特性进行试验研究,分析了ABR在微氧条件下高效运行的可行性。研究结果表明,适量氧的加入能使ABR的COD去除率提高,出水VFA浓度降低。进水COD为4 000 mg/L,HRT为12 h的相同条件下与厌氧相比,微氧ABR出水COD和VFA浓度的降幅分别为63.7%和66%;微氧ABR内氨氮的去除主要通过同步硝化反硝化和短程硝化反硝化作用;适量氧的加入可以提高微生物的产甲烷活性。     

氨氮对生物净化滤柱中铁锰氨氮去除效果的影响

采用培养成熟并稳定运行一段时间的生物除铁除锰除氨氮滤柱,考察进水氨氮浓度变化对铁锰氨氮去除效果的影响。结果表明:进水氨氮从约1.2 mg·L~(-1)逐步提高到约2.0 mg·L~(-1)的过程中,铁、锰和氨氮的去除效果没有受到影响。当进水氨氮超过2 mg·L~(-1)时,进水溶解氧不足,铁的去除效果不受影响;生物除锰受到氨氮升高过程中产生的亚硝氮的抑制,并且与氨氮竞争溶解氧,导致出水锰升高,然而锰氧化菌能够在低溶解氧条件下将锰氧化,出水锰数天后又降到0.05 mg·L~(-1)以下;出水氨氮随进水氨氮的升高而升高。沿程分析发现,进水溶解氧充足时,氨氮和锰的氧化速率没有受到影响;但进水溶解氧不足时,氨氮和锰的氧化速率明显降低;铁的去除速率不受溶解氧的限制。生物净化滤柱可以在较低的溶解氧条件下运行,从而降低能耗。     

新型分段进水脱氮反应器的去污性能研究

基于多段进水工艺原理,结合污泥自回流好氧生物脱氮反应器结构特征开发的新型分段进水脱氮反应器无需硝化液和污泥回流系统,大大简化了系统配置和操作难度。通过调整进水C/N和进水投配比初步研究了该反应器的去污性能。结果表明,新型分段进水脱氮反应器启动完成(21d)后,在进水COD质量浓度为155~455mg/L的条件下,平均出水COD为(39.6±7.3)mg/L,低于《城镇污水处理厂污染物排放标准》(GB 18918—2002)的一级A标准,且出水COD的变异系数为0.18,出水水质较为稳定;TN的去除主要受进水C/N的影响,NH+4-N的去除主要与最后一级的进水投配比有关。本实验的5种运行工况是以出水NH+4-N达标的前提下尽量去除TN为原则进行进水投配比设计的,在5种运行工况下,TN和NH+4-N去除性能良好,最高分别可达76%和89%。采用新型分段进水脱氮反应器处理浙江省实际生活污水(碱度与总凯氏氮平均比值为7.70)时基本无需调节碱度。     

水力停留时间对厌氧折流式反应器处理印染废水运行效果影响的研究

采用厌氧折流式反应器(ABR)处理印染废水。结果表明,在水力停留时间(HRT)为14～32h时,ABR各格室出水COD逐渐降低,HRT越长,COD去除率越高;进水色度为300～500倍,ABR对色度去除效果显著,在HRT为32h时,色度去除率高达75.0%;ABR各格室出水NH3-N均比进水高,第1格室的NH3-N较进水增幅最大;ABR各格室pH呈上升趋势;氧化还原电位(ORP)随ABR格室依次下降;在HRT为14～32h时,BOD5/COD由进水的0.23分别提高到出水的0.31、0.36、0.42、0.40。从运行管理的经济性和提高出水的可生化性考虑,处理印染废水的HRT选择24h为佳。     

Deltas,freshwater discharge,and waves along the Young Sound,NE Greenland

A wide range of delta morphologies occurs along the fringes of the Young Sound in Northeast Greenland due to spatial heterogeneity of delta regimes. In general, the delta regime is related to catchment and basin characteristics (geology, topography, drainage pattern, sediment availability, and bathymetry), fluvial discharges and associated sediment load, and processes by waves and currents. Main factors steering the Arctic fluvial discharges into the Young Sound are the snow and ice melt and precipitation in the catchment, and extreme events like glacier lake outburst floods (GLOFs). Waves are subordinate and only rework fringes of the delta plain forming sandy bars if the exposure and fetch are optimal. Spatial gradients and variability in driving forces (snow and precipitation) and catchment characteristics (amount of glacier coverage, sediment characteristics) as well as the strong and local influence of GLOFs in a specific catchment impede a simple upscaling of sediment fluxes from individual catchments toward a total sediment flux into the Young Sound.     

Predicting diffuse-source transfers of surfactants to surface waters using SWAT

Chemicals present in domestic wastewater can adsorb to solid phase materials during sewage treatment. If biosolids (or sewage sludge) are applied to land, these chemicals can be transferred to soil. Under some circumstances they can also be transferred to surface waters during storm events either in solution or attached to sediment. In this paper we describe the utility of the SWAT 2000 model to estimate diffuse-source surface water exposure to "down-the-drain" chemicals. The model was applied hypothetically to predict the behaviour of linear alkylbenzene sulphonate (LAS), an anionic surfactant commonly used in household detergents, in a small catchment in Bedfordshire, UK, where it has previously been successfully validated for stream flow, sediments and pesticides. LAS transfers were estimated for two scenarios: (1) realistic and (2) reasonable worst case, based on assumptions on sludge application rates and the concentration of LAS in sludge. In addition, the sensitivity of the model output to the proportion of the catchment to which sludge is applied was established. Soil wetness and the total quantity of biosolids applied were the biggest determinants of chemical transport from the catchment. The potential of SWAT as a higher-tier tool in environmental risk assessments is discussed.     

侧入式搅拌槽中多相流流场特性的数值模拟

运用计算流体力学(CFD)技术对不同安装偏角的侧入式搅拌反应器中单相及多相流场进行了数值模拟。模拟结果表明,典型安装偏角下,搅拌槽内流场是由内部围绕搅拌槽中心的高速环形上升流和外部沿搅拌槽壁面的低速下降流组成的大循环流。水平偏角既增加了整个搅拌槽流场的平均速度,有利于固体颗粒在整个搅拌槽内的悬浮性能,又增大了槽底高速流体区域的面积,因而改善了槽底固相沉积状况。竖直偏角增大了槽底高速流体区域的面积,并对槽底施加一定的冲刷作用,从而进一步降低了槽底固相沉积的可能性。无安装偏角时槽底固含率最多的地方主要积聚在搅拌器下方区域。搅拌器在水平偏角θ=10°,竖直偏角φ=5°时槽底大部分区域的固含率分布较均匀,仅在槽底搅拌器右侧的壁面区域存在小面积的固含率较高区域,在该安装偏角下整个搅拌槽的固液悬浮性能及防止底部固相沉积性能达到最佳。     

Quantifying sediment-associated metal dispersal using Pb isotopes: Application of binary and multivariate mixing models at the catchment-scale

In this study Pb isotope signatures were used to identify the provenance of contaminant metals and establish patterns of downstream sediment dispersal within the River Maritsa catchment, which is impacted by the mining of polymetallic ores. A two-fold modelling approach was undertaken to quantify sediment-associated metal delivery to the Maritsa catchment; employing binary mixing models in tributary systems and a composite fingerprinting and mixing model approach in the wider Maritsa catchment. Composite fingerprints were determined using Pb isotopic and multi-element geochemical data to characterize sediments delivered from tributary catchments. Application of a mixing model allowed a quantification of the percentage contribution of tributary catchments to the sediment load of the River Maritsa. Sediment delivery from tributaries directly affected by mining activity contributes 42-63% to the sediment load of the River Maritsa, with best-fit regression relationships indicating that sediments originating from mining-affected tributaries are being dispersed over 200 km downstream.     

生物质碳源组合型生态浮床系统脱氮效果研究

利用农业废弃物和水生植物,结合水下空间与水面景观,构建集成脱氮技术的新型立体组合式生态浮床系统用以地表水体中氮的脱除以净化水质。立体生态浮床运行2个月之后的结果显示,NH3-N、TN和CODMn的去除率可分别达到96.77%、95.51%和77.75%,本浮床具有较高脱氮能力,水体净化效果明显;同时,整个生态浮床系统的生物多样性较为丰富,原水分别为Ⅴ类和劣Ⅴ类的池2和池5中分别鉴定出6种和8种主要氨氧化菌谱带,位于系统中部的玉米芯和稻草表面微生物多样性丰富程度较高;稻草和底泥中氨氧化菌的谱带种类最多。与池2相比,池5中除了存在共有谱带外,还存在特有谱带h和j带,表明可能有特殊氨氧化菌群的存在。本组合型生态浮床具有同步硝化与反硝化作用,利于沉水植物生长,并能促进水生态系统构建。     

Quantifying the importance of diffuse minewater pollution in a historically heavily coal mined catchment

There has been considerable progress in developing treatment systems for point sources of minewater pollution in recent years; however, there remains a knowledge gap in the characterisation and remediation of diffuse minewater sources. Data are presented from the River Gaunless catchment, a historically heavily coal mined catchment in the northeast of England. Instream iron (Fe) loadings were monitored alongside loadings arising from point minewater discharges over a 12-month period to assess the dynamic importance of diffuse sources of minewater pollution. In low flow, diffuse sources account for around 50% of instream loading, a proportion which increases to 98% in high flow conditions. The low flow sources appear to be dominated by direct discharge of contaminated groundwater to surface waters in lower reaches of the catchment. In high flow, resuspended Fe-rich sediments, which are both naturally occurring and derived from historic mining, become the dominant diffuse source of Fe in the water column.     

Assessing the effect of natural controls and land use change on sediment yield in a major Andean River: the Magdalena drainage basin, Colombia

The Magdalena River, a major fluvial system draining most of the Colombian Andes, is a world-class river, in the top 10 in terms of sediment load (approximately 150 MT/yr). In this study, we explore the major natural factors and anthropogenic influences behind the patterns in sediment yield on the Magdalena basin and reconstruct the spatial and temporal pattern of deforestation and agricultural intensification across the basin to test the relationships between land use change and trends in sediment yield. Our results show that sediment yield for the whole Magdalena catchment can be explained by natural variables, including runoff and maximum water discharge. These two estimators explain 58% of variance in sediment yield. Temporal analyses of sediment discharges and land use show that the extent of erosion within the catchment has increased over the last 10 to 20 years. Many anthropogenic influences, including a forest decrease by 40% in a 20-year period, an agriculture and pasture increase by 65%, poor soil conservation and mining practices, and increasing rates of urbanization, may have accounted for the overall increasing trends in sediment yield on a regional scale.     

Characterising the hydrological regime of an ungauged temporary river system: a case study

Temporary streams are characterised by specific hydrological regimes, which influence ecosystem processes, groundwater and surface water interactions, sediment regime, nutrient delivery, water quality and ecological status. This paper presents a methodology to characterise and classify the regime of a temporary river in Southern Italy based on hydrological indicators (HIs) computed with long-term daily flow records. By using a principal component analysis (PCA), a set of non-redundant indices were identified describing the main characteristics of the hydrological regime in the study area. The indicators identified were the annual maximum 30- and 90-day mean (DH4 and DH5), the number of zero flow days (DL6), flow permanence (MF) and the 6-month seasonal predictability of dry periods (SD6). A methodology was also tested to estimate selected HIs in ungauged river reaches. Watershed characteristics such as catchment area, gauging station elevation, mean watershed slope, mean annual rainfall, land use, soil hydraulic conductivity and available water content were derived for each site. Selected indicators were then linked to the catchment characteristics using a regression analysis. Finally, MF and SD6 were used to classify the river reaches on the basis of their degree of intermittency. The methodology presented in this paper constitutes a useful tool for ecologists and water resource managers in the Water Framework Directive implementation process, which requires a characterisation of the hydrological regime and a ‘river type’ classification for all water bodies.     

Release of PCBs from Silvretta glacier (Switzerland) investigated in lake sediments and meltwater

This study is part of our investigations about the release of persistent organic pollutants from melting Alpine glaciers and the relevance of the glaciers as secondary sources of legacy pollutants. Here, we studied the melt-related release of polychlorinated biphenyls (PCBs) in proglacial lakes and glacier streams of the catchment of the Silvretta glacier, located in the Swiss Alps. To explore a spatial and temporal distribution of chemicals in glacier melt, we combined two approaches: (1) analysing a sediment record as an archive of past remobilization and (2) passive water sampling to capture the current release of PCBs during melt period. In addition, we determined PCBs in a non-glacier-fed stream as a reference for the background pollutant level in the area. The PCBs in the sediment core from the Silvretta lake generally complied with trends of PCB emissions into the environment. Elevated concentrations during the most recent ten years, comparable in level with times of the highest atmospheric input, were attributed to accelerated melting of the glacier. This interpretation is supported by the detected PCB fractionation pattern towards heavier, less volatile congeners, and by increased activity concentrations of the radioactive tracer ¹³⁷Cs in this part of the sediment core. In contrast, PCB concentrations were not elevated in the stream water, since no significant difference between pollutant concentrations in the glacier-fed and the non-glacier-fed streams was detected. In stream water, no current decrease of the PCBs with distance from the glacier was observed. Thus, according to our data, an influence of PCBs release due to accelerated glacier melt was only detected in the proglacial lake, but not in the other compartments of the Silvretta catchment.     

The Pb pollution fingerprint at Lochnagar: the historical record and current status of Pb isotopes

Ratios of 206Pb/207Pb in a Lochnagar sediment core slowly decline from c. 1.32 at 140 cm to c. 1.23 at 9 cm, and then rapidly decline to c. 1.15 at the surface. Ninety percent of the Pb in the surface sediments can be attributed to anthropogenic sources. The 206Pb/207Pb ratio data imply that catchment peat surface contains a higher fraction of anthropogenic Pb than the sediment surface. The 206Pb/207Pb ratios in the surface of the sediment core are consistent with ratios in trapped sediments collected annually between 1998 and 2003. However, there is no significant decline in these recent samples suggesting that the reduction in atmospheric Pb emissions has not yet been recorded by the sediments due to Pb inputs from the catchment. As catchment peats store about 840 kg previously deposited anthropogenic Pb since 1860, it is likely that catchment inputs will continue to affect future 206Pb/207Pb ratios.