接触氧化法处理染色废水的设计与试运转

本文介绍了采用生物接触氧化法处理染色废水的设计与工程试运转.运行结果表明,当废水原水COD_(Cr)平均浓度为546mg/L、色度为448倍时,处理COD_(Cr)去除率68%,色度去除率86%,出水能达标排放.     

强化混凝去除微污染水源水中镉(Ⅱ)的研究

针对微污染水源水中的Cd(Ⅱ)污染去除,以聚硫酸铁(PFS)为混凝剂,采用强化混凝对水中微量Cd(Ⅱ)的去除进行了研究。考察了pH、PFS投加量、Cd(Ⅱ)初始浓度和原水浊度等因素对Cd(Ⅱ)去除的影响。结果表明,在pH≥9的条件下,当原水中Cd(Ⅱ)为0.1mg/L时,投加3.75mg/L的PFS(以Fe计),可使滤后水Cd(Ⅱ)剩余浓度降至0.005mg/L以下,满足《生活饮用水卫生标准》(GB5749—2006)要求;当水中Cd(Ⅱ)初始浓度较高时,适当增加PFS投加量即可使镉得到有效去除。强化混凝是去除微污染水源水中Cd(Ⅱ)污染的经济、有效方法之一。     

粉末活性炭处理抗生素污染原水试验研究

探讨了粉末活性炭对抗生素的去除效果.在对水体中30种常见抗生素污染调研的基础上,选取萘啶酸、土霉素、林可霉素3种代表性抗生素进一步分析所需粉末活性炭的投加量.研究结果表明:当污染物在1 mg/L时,粉末活性炭的投加量分别为115 mg/L(萘啶酸)、75 mg/L(土霉素)、25mg/L(林可霉素),去除率均在99％以上,并根据其他抗生素的吸附难易度,推导出在相同污染程度下粉末活性炭的投加量;当原水中出现小于1 μg/L的持续性污染时,粉末活性炭的投加量应保持在1～35 mg/L,以保证稳定高效的去除效果.     

基于分形理论的结构面迹长分布模式及连通率影响因素分析

对结构面迹长的描述与估计对计算结构面连通率至关重要。目前,描述基体裂隙迹长的方法通常偏重于平均迹长的估计,难以精确描述结构面迹长的空间发育状况。基于分形理论,利用分形维D描述了结构面迹长分布模式。如果结合结构面迹长区间、优势迹长区间及其内裂隙发育的相对数量I(%),即可详细描述基体裂隙迹长的空间发育状况。以西南某大型水电站工程坝区建基面的基岩裂隙为例,对分形维D和裂隙发育的相对数量I(%)进行分类和组合,总结出结构面迹长发育的3种模式:M1、M2和M3,并探讨了各种迹长发育模式下,连通率k的影响控制因素。结果发现,当裂隙迹长的发育模式为M1和M2时,结构面的空间分布状况对连通率k的影响较大;当裂隙迹长的发育模式为M3时,连通率k主要与裂隙迹长的平均值L0有关,相应裂隙空间分布对k的影响较小。     

P-Ⅲ型分布矩法估计量有偏改正的统计试验

引言在样本观测值的总体分布函数形式已知时,水文频率分析中,用以估计总体参数的方法主要有三种:矩法、极大似然法和适线法。在似然函数可解的条件下,理论和实践证明,在常用的估计方法中,极大似然估计量有效性最好。但由于似然函数有时无解(例如,P—Ⅲ型分布中C_S>2时):迭代计算,工作繁复;非简单样本(例如,洪水分析中加入历史调查洪水资料)求解假定欠     

SBR法处理食品废水的工艺设计及运行

介绍了采用间歇式活性污泥 (SBR)法处理食品生产废水的工艺和运行情况。当进水COD在 693～ 15 30mg/L时 ,经过SBR处理后的出水可达到国家《污水综合排放标准》(GB8978-96) ,主要污染物COD≤ 10 0mg/L。     

天津石化公司纯氧活性污泥法处理厂简介

天津石化公司纯氧活性污泥法处理厂的设计参数为:曝气池 MLSS=5g/L,F/M=0.4,泥龄6～10天;二沉池水力负荷0.47m~3/(m~2·h),固体负荷84kg/(m~2·d)。当进水 BOD_5=560mg/L,COD_(cr)=800mg/L 时,出水 BOD_5<25mg/L,COD_(cr)<90mg/L。与普通曝气池相比,其所需的动力总功率降低50%,基建用地节省三分之一。     

臭氧—活性炭—超滤组合工艺处理石油微污染水的试验研究

采用臭氧-活性炭-超滤(O3-GAC-UF)处理石油微污染水,研究该组合工艺对水中石油污染物的去除效果.结果表明,当原水油含量为4 mg/L左右时,在臭氧投加量约为4 mg/L、反应时间为12 min、活性炭停留时间为12 min条件下,超滤出水油含量为0.027 mg/L,对色度、浊度和CODMn的去除率均接近100%,UV254从0.117 cm-1降低为0.004 cm-1,并且随着处理水量的增加,系统运行稳定.臭氧-活性炭-超滤工艺可以作为处理石油微污染水的一种有效方法.     

基于测量不确定度的电力系统状态估计（三）算法比较

加权最小二乘估计准则在电力系统状态估计中应用广泛,但其结果易受不良测点影响。为解决这一问题,已经提出了加权最小绝对值准则、非二次准则等估计器。应用大量算例,对已有估计准则和文中所提出的以最大测点正常率为目标的状态估计方法进行了对比研究,进一步对残差污染情况进行了讨论。算例表明,在估计结果合理性方面,当测点中不含不良数据时,文中所提出的方法与加权最小二乘估计相当,优于其他方法;当测点中含有不良数据时,文中所提出的方法大幅度优于以往状态估计方法,说明所提出的方法可较好地解决残差污染问题。     

水文频率分析中修改双权函数法的研究与应用

修改的双权函数法（MDWF）是将两个负指数型函数之差所构成的函数类取作权函数。对于皮尔逊Ⅲ型分布,它能使σ和Cs的估计由原权函数法的二阶加权中心矩降低为一阶加权中心矩估计。采用Monte—Carlo模拟分析技术,以设计值估计的不偏性和有效性为评价标准,将MDWF法与近年来在水文频率分析中得到广泛研究和应用的线性矩法（L-M）进行比较。统计试验结果表明,两种方法的无偏性、有效性均相当。采用全国范围内26个站点的洪水极值资料对MDWF方法的实际应用效果进行了验证,拟合结果表明,与L—M法相比。MDWF的整体拟合效果略优。     

Robustness of an aerobic metabolically vinyl chloride degrading bacterial enrichment culture

Degradation of the lower chlorinated ethenes is crucial to the application of natural attenuation or in situ bioremediation on chlorinated ethene contaminated sites. Recently, within mixtures of several chloroethenes as they can occur in contaminated groundwater inhibiting effects on aerobic chloroethene degradation have been shown. The current study demonstrated that metabolic vinyl chloride (VC) degradation by an enrichment culture originating from groundwater was not affected by an equimolar concentration (50 μM) of cis-1,2-dichloroethene (cDCE). Only cDCE concentrations at a ratio of 2.4:1 (initial cDCE to VC concentration) caused minor inhibition of VC degradation. Furthermore, the degradation of VC was not affected by the presence of trans-1,2-dichloroethene (tDCE), 1,1-dichloroethene (1,1-DCE), trichloroethene (TCE), and tetrachloroethene (PCE) in equimolar concentrations (50 μM). Only cDCE and tDCE were cometabolically degraded in small amounts. The VC-degrading culture demonstrated a broad pH tolerance from 5 to 9 with an optimum between 6 and 7. Results also showed that the culture could degrade VC concentrations up to 1,800 μM (110 mg/L).     

Isolation of Free Living Amoebas as a Highly Sensitive Index of Water Contamination

Abstract

Safe drinking water is a rare commodity in India. Several water borne diseases are commonly reported from metropolitan cities of India, most likely due to unsatisfactory disinfection of municipal water. The analysis of the microbiological flora of the water supplied for drinking purposes shows that New Delhi water is biologically contaminated. Six hundred water samples obtained from New Delhi residential complexes included 96 from direct taps, 310 from overhead tanks used for storing the same water for urgent needs, and 194 were from water filter residues. The samples were repeatedly collected in every season for two consecutive years. Ninety percent of the water samples were found to be biologically contaminated. Most contaminated samples were from overhead water tanks (97.4 percent) and from filter residues (94.5 percent). Even direct tap water was found to be contaminated in more than 50 percent of the samples. The most common isolates were from the protozoan category, the free living amoeba (90.1 percent) and by aerobic bacteria (73.0 percent). Overhead tank water samples were co-contaminated with as many as 15 microorganisms. Isolation of free living amoebae was found to be the most sensitive tool of analyzing the water safety. It is proposed that after determining the microbiological contamination, the public health laboratories should modify the existing technique and must perform the cultures for free living amoebae on non-nutrient agar in addition to the standard coliform test.     

The application of surface engineered silica for the treatment of sugar containing wastewater

The removal of sucrose and fructose from water at various high concentrations by surface engineered silica (SES) was studied using dissolved sugar in pure water. The results indicate that sugar at concentrations of up to 800 g/L can be removed by SES at a relatively high dose of 250 to 300 g/L. Based on these results, process water from a soft drink filling station which was contaminated by sugar, flavour components, Escherichia coli, Pseudomonas aeruginosa bacteria and Candida pelliculosa yeast were treated to study the performance of SES using actual process water samples by analysing turbidity, biological oxygen demand (BOD), UV absorption, and various other standard parameters, and microbial tests. The study shows that at a dose of 100 g/L of SES bacterial contamination as well as turbidity, BOD and UV absorption can be significantly reduced. However, the study found the yeast species Candida pelliculosa could not be removed from the water samples.     

Plant algae method for arsenic removal from arsenic contaminated groundwater

Field studies were carried out in Urumqi River Basin in Northwest China. The study focused on experimentation on a plant algae method that was tested by taking various water chemistries into consideration. The results from a greenhouse experiment evaluated for four doses of P (0, 100, 200, and 300 μmol/L) using two ferns (30 and 60 day old) on 15 L of contaminated groundwater per plant revealed that the biomass of 30-day old ferns gained was higher than 60-day fern. As solution-P increased from 0 to 450 μmol/L, Phosphorus concentration in the fronds increased from 1.9 to 3.9 mg/kg and 1.95 to 4.0 mg/kg for 30-d and 60-d ferns respectively. This study showed that the plant algae method may be a good solution to maximize arsenic uptake in the short term under normal climatic conditions.     

Analysis of effect of nicotine on microbial community structure in sediment using PCR-DGGE fingerprinting

Solid or liquid waste containing a high concentration of nicotine can pollute sediment in rivers and lakes, and may destroy the ecological balance if it is directly discharged into the environment without any treatment. In this study, the polymerase chain reaction(PCR) and denaturing gradient gel electrophoresis(DGGE) method was used to analyze the variation of the microbial community structure in the control and nicotinecontaminated sediment samples with nicotine concentration and time of exposure. The results demonstrated that the growth of some bacterial species in the nicotine-contaminated sediment samples was inhibited during the exposure. Some bacteria decreased in species diversity and in quantity with the increase of nicotine concentration or time of exposure, while other bacteria were enriched under the effect of nicotine, and their DGGE bands changed from undertones to deep colors. The microbial community structure, however, showed a wide variation in the nicotinecontaminated sediment samples, especially in the sediment samples treated with high-concentration nicotine. The Jaccard index was only 35.1%between the initial sediment sample and the sediment sample with a nicotine concentration of 0.030 mg/g after 28 d of exposure. Diversity indices showed that the contaminated groups had a similar trend over time. The diversity indices of contaminated groups all decreased in the first7 d after exposure, then increased until day 42. It has been found that nicotine decreased the diversity of the microbial community in the sediment.     

Decontamination of wastewater contaminated by polychlorinated biphenyls (PCBs).

Wastewater contaminated by PCBs obtained from three different sources was treated at both laboratory and pilot plant scale conditions by ultraviolet oxidation of organics at the presence of hydrogen peroxide after partial adsorption of impurities and PCBs on activated carbon and/or activated bentonite. The procedure was conducted both with and without a Fe(II) catalyst and considerable reduction of PCB concentration was achieved in both cases. In pilot plant scale experiments, activated carbon polishing step followed UV oxidation. The following three types of contaminated waste water were examined: a) aqueous extracts originated in the course of clean-up of contaminated soil by extraction with aqueous solvents. Concentrations of PCBs in extracts were between 1 microg/L to 3,000 microg/L; b) wastewater condensates originated in the process of thermal desorption of PCB from soils. Concentrations of PCBs in condensates were between 300 microg/L and 5,000 microg/L. c) underground water contaminated by PCBs extracted from the sites of old contamination. The content of PCBs was up to 50,000 ng/L. Biodegradation of PCBs with a mixture of indigenous soil bacteria (selected strains of Pseudomonas and Acitenotobacter) was also tested. It was carried out in a reactor with volume of 1.5 m3 by application of the bacteria in a slurry of bentonite with adsorbed PCBs.     

From Mountain Ranges to Sweeping Plains,in Droughts and Flooding Rains; River Murray Water Quality over the Last Four Decades

The aim of this paper was to analyse the spatial and temporal patterns and drivers of water quality in a large arid/semi-arid river system (River Murray, Australia) using a long term (1978???2015) dataset collected from 24 monitoring sites. The water quality is highly variable, but on average electrical conductivity (EC), pH, turbidity, dissolved and total nutrient, colour and chlorophyll a levels increase with distance downstream from the headwaters to the lower reaches. This is a function of the natural accumulation of dissolved and particulate components and intermittent, mostly diffuse source, pollutant inputs. The Darling tributary inflow increases turbidity, total phosphorus and pH in the main River Murray channel. Based on long-term trend analysis at four representative sites, EC, nutrients and colour showed declining trends on average at most sites except in the headwaters. Increased flow increases concentrations of most quality parameters, although at very high flows decreases in pH, EC, turbidity and oxidized nitrogen were apparent at many sites. The extreme “Millennium” drought (2002???2009) period resulted in lowered concentrations of many water quality parameters, indicating retention in the landscape. In the post-drought flooding (2010???2012) period a large amount of organic material was mobilised, resulting in much higher peak colour concentrations than when mid-range flooding was more frequent. It is critical that this monitoring program is continued as a Basin-wide water management plan is implemented.

     

Determination of perfluorinated compounds (PFCs) in solid and liquid phase river water samples in Chao Phraya River, Thailand

Perfluorinated compounds (PFCs), especially perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are fully fluorinated organic compounds, which have been used in many industrial applications. These chemicals have contaminated surface water all over the world even in developing countries like Thailand. The previous study showed the contamination in Chao Phraya River in 2006 and 2007. The purposes of this field study were to determine the solid and liquid phase of PFCs contamination in Chao Phraya River and to compare the changes of PFC concentration in 2008. Surveys were conducted in the lower reach of Chao Phraya River in the industrialized area. A solid phase extraction (SPE) coupled with HPLC-ESI-MS/MS were used for the analysis for ten PFCs. Ten PFCs were analyzed to identify the contamination in both solid and liquid phases. PFCs were detected in both the solid and liquid phase in every sample. PFOA was the most dominant PFC while PFPA and PFOS were also highly detected in most samples. The average loadings of PFPA, PFOA and PFOS in Chao Phraya River were 94.3, 284.6 and 93.4 g/d, respectively. PFOS concentrations did not show differences between 2006 and 2008. However, PFOA concentrations were higher in 2008/5/26, while comparing other samplings. The ratio of solid:liquid PFPA (2.1:1.0) [(ng/g)/(ng/L)] was lower than PFOA (13.9:1.0) [(ng/g)/(ng/L)] and PFOS (17.6:1.0) [(ng/g)/(ng/L)]. The shorter chain (more hydrophilic) PFC was better to dissolve in water rather than adsorb onto suspended solids. PFOS also showed more potential to attach in the suspended solids than PFOA.     

Model Based Assessment of Nitrate Pollution of Water Resources on a Federal State Level for the Dimensioning of Agro-environmental Reduction Strategies

The main goal of the project was to assess nitrogen pollution of surface waters and groundwater in the Federal State of North Rhine Westphalia (NRW), Germany. For this purpose the hydro(geo-)logical models GROWA-DENUZ/WEKU were coupled to the agro-economic model RAUMIS in order to assess the diffuse nitrogen loads and to approaches to determine the nitrogen loads from point sources. In this way the complex socio-economic interrelations and hydrological/hydrogeological interdependencies were simultaneously. The model network was applied consistently across the whole territory of NRW. At first the actual N inputs into groundwater and surface waters resulting from diffuse sources and point sources were assessed. For the relevant diffuse input pathways (groundwater runoff, drainage runoff and natural interflow) this was done in a spatial resolution of 100 m???100 m. In the case of point source inputs information from municipal waste water treatment plants, industrial effluents, rainwater sewers and combined sewer overflows has been considered. For NRW an actual total N input into surface waters of ca. 117.000 t???a^?1?N has been quantified. As the inputs via natural interflow (ca. 30 %), groundwater runoff (ca. 26 %) and drainage systems (ca. 18 %) hold the largest portion, it is evident that measures to control nitrate pollution have to focus on the inputs from diffuse sources. For this purpose, initially the development of the agrarian sector according to the Common Agricultural Policy, CAP until 2015 including supplementary measures and other impact factors has been analysed. The impact of this so-called baseline scenario 2015 was predicted for both, the diffuse N surpluses and the N pollution of groundwater and surface waters. It could be shown that the baseline projections for the agricultural sector through 2015 may lead to decrease of the diffuse N inputs into groundwater by ca. 13.500 t???a^?1?N and an overall decrease of the diffuse N inputs into surface waters by ca. 25.000 kg???ha^?1???a^?1?N. Based on the baseline scenario 2015 the additional N reduction to guarantee nitrate concentrations in groundwater below the EU-threshold value of 50 mg???l^?1 NO₃ was determined by means of a backward model calculation. This was done using the predicted nitrate concentrations in the leachate 2015 for the individual 100 m???100 m grids as starting points. In this way for the whole territory of NRW an additional N reduction beyond the baseline scenario 2015 of ca. 12.000 t???a^?1?N has been assessed. Model results indicate that additional N reduction measures don’t have to be implemented area-covering in order to be efficient, but in certain subareas only. It is suggested that in these subareas the available financial resources for the implementation of N reduction measures shall be used for individual, i.e. regionally adapted nitrate reduction measures.     

Assessing Contamination in Great Lakes Sediments Using Benthic Invertebrate Communities and the Sediment Quality Triad Approach

Sediments in many Great Lakes harbors and tributary rivers are contaminated. As part of the USEPA's Assessment and Remediation of Contaminated Sediment (ARCS) program, a number of studies were conducted to determine the nature and extent of sediment contamination in Great Lakes Areas of Concern (AOC). This paper describes the composition of benthic invertebrate communities in contaminated sediments and is one in a series of papers describing studies conducted to evaluate sediment toxicity from three AOC's (Buffalo River, NY; Indiana Harbor, IN; Saginaw River, MI), as part of the ARCS Program. Oligochaeta (worms) and Chironomidae (midge) comprised over 90% of the benthic invertebrate numbers in samples collected from depositional areas. Worms and midge consisted of taxa identified as primarily contaminant tolerant organisms. Structural deformities of mouthparts in midge larvae were pronounced in many of the samples. Good concurrence was evident between measures of laboratory toxicity, sediment contaminant concentration, and benthic invertebrate community composition in extremely contaminated samples. However, in moderately contaminated samples, less concordance was observed between the benthos community composition and either laboratory toxicity test results or sediment contaminant concentration. Laboratory sediment toxicity tests may better identify chemical contamination in sediments than many commonly used measures of benthic invertebrate community composition. Benthic measures may also reflect other factors such as habitat alteration. Evaluation of non-contaminant factors are needed to better interpret the response of benthic invertebrates to sediment contamination.