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1.
Reusing reclaimed wastewater from lakes has become one of the most effective measures to relieve the urban ecological crisis. However, reclaimed wastewater still contains large amounts of nutrient salts, trace organic pollutants, suspended solid particles and microorganisms, which may significantly affect the aquatic ecosystems. The health of aquatic ecosystems can be directly and effectively monitored by evaluating the biofilms in them, because the structures of biofilms are directly affected by multiple environmental factors. Therefore, it is important to study the structures of biofilms attached on multiple medium surfaces in river-lake systems that contain reclaimed wastewater. In this study, the paper applied scanning electron microscope (SEM) technology and fractal theory to quantitatively describe the structural characteristics of biofilms attached on the medium surfaces of aquatic plants and gravels in the Lianshi Lake of Beijing Yongding River and other two kinds of reclaimed water of the river-lakes, whose sewage treatment processes were the combined process of deposit and sand filtration and UF membrane filtration, plus anaerobic-anoxic-oxic process, respectively. The paper found that these two types of biofilms were typical porous media and their basic skeletons were mainly composed of inorganic particles, microorganisms, and algae. Furthermore, most areas between the particles were filled with extracellular polymers (EPS) secreted by bacteria. At the same time, these biofilms showed obvious fractal and multifractal characteristics, but the fractal dimensions alone failed to effectively describe the complexity of biofilm structures. The multifractal spectra were able to quantitatively characterize the biofilms’ heterogeneity. In addition, the number of microorganism species, the quantity and the heterogeneity of aquatic plants’ surface biofilms were all higher than those of gravel surface biofilms, most likely due to the effects of light. In addition, the heterogeneity of biofilms in reclaimed water treated by the combined process of deposit and sand filtration and UF membrane filtration plus anaerobic-anoxic-oxic process was higher than that of biofilms in reclaimed water treated by traditionally activated sludge process (Lianshi Lake’s water). Besides, the non-uniformity of biofilms in reclaimed water treated by combined process of deposit and sand filtration was higher than that of biofilms in reclaimed water treated by UF membrane filtration plus anaerobic-anoxic-oxic process.  相似文献   

2.
Biofouling, associated with membranes, is considered as a major operational challenge in membrane bioreactor (MBR) technology. Interrupting the process for the formation of biofilm by the action of interspecies quorum quenching (QQ) has received a significant attention since recent years. An antifouling bacterial consortium was identified to improve biofouling inhibition performance during MBR operation. For this purpose, various QQ bacteria were isolated from laboratory-scale MBR using enrichment culture method and identified via 16S rRNA. Potential quenching strains including Enterobacter cloaca, Delftia sp., and Pseudomonas sp. were utilized to control biofouling in the MBR operated in the continuous mode for 38 days. Three laboratory-scale MBRs, including two MBRs with different anti fouling consortium and a control, were operated in parallel under similar operating conditions. Biofouling control by QQ bacteria was compared based on the membrane permeability and EPS secretion from biofilm on the membrane. Both MBRs with antifouling consortium (AC-MBRs) experienced around three times less biofouling as compared to conventional MBR leading to significant decrease in acyl homoserine lactones (AHLs) concentration in the biocake. More than 90, 45, and 49% of COD, NH4–N, and PO4 3?–P removal efficiencies elucidate that QQ bacterial consortium could effectively reduce membrane biofouling without compromising the MBR efficiency. Comparatively lower concentration of bound EPS in AC-MBRs restricted the bacterial adhesion to membrane resulting in enhanced membrane permeability depicting that a broader range of signal molecules could be hydrolyzed using antifouling consortium than single or no QQ strain in the submerged MBR.  相似文献   

3.
沈丽娜 《地下水》2011,(6):193-194,212
针对目前许多城市将新型大学园区规划在城郊风景区域,远离城市市政管网,大学园区内污水处理和资源化这一个特殊问题,提出具有普遍应用性的解决方案。研究校区内生活、办公过程中产生的废水进行生物处理,使之达到中水水质标准,作为校区内的生活杂用水,用来冲厕、绿化、冲洗和水景用水,达到水资源的重复利用,节约资源的目的。  相似文献   

4.
Fenton氧化膜-生物反应器出水中丙烯腈的实验研究   总被引：4，自引：0，他引：4  
采用膜-生物反应器和Fenton氧化组合工艺对丙烯腈废水进行处理。从GC/MS测量结果来看,膜-生物反应器出水中主要物质为2,6双（二甲基-乙基）-4-酚、苯二甲酸和硝基苯二甲酸,均为生物难降解有机物,使出水不能达标。后续Fenton氧化工艺处理膜生物反应器出水,可以使COD含量等指标达到所要求的排放标准。经过膜-生物处理与Fenton法结合的优化工艺,COD去除率达到80%~88%,去除率达到98%,出水水质可达排放标准。Fenton氧化工艺的最佳工艺条件为：pH值为3.4,硫酸亚铁的投加量为700mg/L,双氧水的投加量为600mg/L。  相似文献   

5.
The properties of activated sludge are very important in a membrane bioreactor (MBR) in terms of membrane fouling. The most important parameters affecting the membrane fouling can be listed as mixed liquor suspended solid (MLSS) concentration, soluble microbial products (SMPs), extracellular polymeric substances (EPSs), floc size, aeration and viscosity of both supernatant and activated sludge. The COD/TKN ratio also affects the physical properties of sludge in MBR system. This study aimed to investigate the effect of chemical oxygen demand-to-total Kjeldahl nitrogen (COD/TKN) ratio of feed wastewater treated in an MBR on biological components of activated sludge. The activated sludge characteristics were determined by quantitative analyses such as MLSS, EPS, SMP, floc size distribution, zeta potential, relative hydrophobicity and capillary suction time in a submerged MBR treating simulated wastewater having different COD/TKN ratios (16, 56 and 107). The COD and TKN removal efficiencies were found to be almost equal in the sMBRs having different COD/TKN ratios. However, it was seen that the EPS content and SMP concentration in the supernatant increased with increasing COD/TKN ratio. The results indicated that the COD/TKN ratio of feed should be considered as an effective parameter on activated sludge properties in sMBR systems.  相似文献   

6.
膜生物反应器处理难降解废水的特性研究   总被引：3，自引：3，他引：0  
膜生物反应器与生物接触氧化法处理难降解废水的对比研究表明,在相同的运行条件下,膜生物反应器比生物接触氧化法具有更稳定的出水水质,其平均出水CODcr去除率达到88.41%,比接触氧化法提高了近30%;其平均色度去除率达到85.27%,相比接触氧化法,提高了近30%。通过出水分子量组成分析发现,膜出水以分子量介于3 000和10 000之间的物质为主,占总数的88.36%,接触氧化以分子量大于10 000的物质为主,占总物质的72.04%,介于3 000和10 000之间的仅占9.76%。  相似文献   

7.
采用一套新型生物组合工艺(CSTR产酸发酵反应罐-UASBAF复合厌氧反应池-NMBR新型多级环流膜生物反应器)处理玉米深加工企业生产废水。研究结果表明:经过50d的启动期后系统进入稳定运行阶段,在稳定运行的155d内,组合工艺对COD和BOD的去除率高达99.4%和99.8%。基于厌氧消化数学模型(ADM1)和活性污泥数学模型(ASM1)对本组合工艺进行数学模拟研究,结果表明,该模型对每个工艺的出水COD预测平均误差均在15%以内,表明该模型对这套新型工艺具有很好的预测效果。  相似文献   

8.
基于潮白河流域再生水的场地回灌,为提高抗生素甲氧苄氨嘧啶（TMP）的去除率,降低其进入地下水的风险,选用价格低廉对TMP有高效去除性能的黏土陶粒作为吸附剂,构建去除TMP的人工复合土柱。吸附实验研究结果显示黏土陶粒对TMP吸附容量达到151.824 μg/g,具有去除再生水中TMP能力;TMP在黏土陶粒解吸过程中存在解吸滞后性的现象。柱实验研究结果表明此人工复合土柱能够有效地去除再生水中TMP,去除率高于95%,其去除机制主要是吸附与生物降解协同作用。本研究建立的人工复合土层系统能有效地去除再生水中TMP,对实际场地回灌工程具有指导性作用。  相似文献   

9.
土壤阳离子交换容量(CEC)、总有机碳(TOC)、粘土矿物总量和粘粒含量是影响再生水入渗过程中污染物在包气带及地下水含水层介质中迁移转化的四项重要指标,是反映包气带对污染物吸附性及生物作用的主要参数。本文选取北京市潮白河顺义段再生水补给区包气带作为对象,对CEC、TOC、粘土矿物总量及粘粒含量4项指标进行了两两相关性分析及函数拟合。结果表明,上述四项指标的大小均与埋深无关,只与介质本身特性有关,且两两之间存在着显著的相关性,相关系数均大于0.8。  相似文献   

10.
This study aims to describe the application of water pinch technology in industrial water consumption management in aluminum anodizing industry. Water pinch analysis is a systematic technique for designing, optimization and retrofitting of energy, mass and water recovery networks. The selection of different operations existing in an industry has an important role in correctness of application of pinch technology. Water usages in anodizing industry are various, but researches have been shown that, it has the best efficiency on the selection of rinsing chambers to pinch technology. There are different methods in pinch technology mostly based on mass transfer of single or multiple contaminants. In this research, a new method is used to select effective contaminant to be applied to pinch analysis. This research is based on Mann and Liu’s method in single contaminant. But “the guide for classification of raw water, wastewater and recycled water for industrial and recreation” is chosen to use a complex of index contaminants as a single contaminant. This method is very simple and applicable for various industrial processes. By an index contaminant like total dissolved solids, the water usage reduced about 6.7 %. Using pinch technology and this new approach in three rinsing chambers, water usage reduced about 14.4 %.  相似文献   

11.
把城市污水净化处理为符合回灌标准的再生水并安全回灌补给地下水, 对于实现污水资源化、含水层恢复、缓解我国水资源供需矛盾和环境污染态势具有重要意义.针对再生水回灌地下水存在的水质安全问题, 通过理论分析、系列实验和技术集成形成了再生水地表回灌补给地下水的水质安全保障体系及关键技术.该安全保障体系包括场地选择与勘查、高效低成本的再生水处理技术、土壤—含水层系统数学模型和回灌方案设计技术、水质监控系统、安全评价技术以及回灌管理法规等.这些要素相互依赖、相互作用, 构成一个完整的体系.郑州郊区示范工程证实了该水质安全保障体系的可行性.2年示范工程表明, 处理的再生水水质达到《城市污水再生利用地下水回灌水质》(GB/T 19772-2005)标准, 优于场地背景地下水水质, 补给含水层后的地下水基本达到《地下水质量标准》(GB/T 14818-1993)Ⅲ类水标准.建议有关政府部门把再生水利用及回灌补给地下水, 纳入水资源开发利用及环境保护规划的整体框架中, 尽快制定或完善再生水回灌补给地下水的相关法律、法规和标准体系, 建立再生水回灌许可证制度, 有序推进再生水回灌工程.   相似文献   

12.
Reuse of reclaimed water for the eco-environmental water has become an effective measure to resolve the urban water crisis. However, it still contains large amounts of contaminants which may significantly affect the aquatic ecosystems. Biofilm attached on the surface of multiple matrixes in rivers and lakes is one of the indicators for describing the health of aquatic ecosystem. In this article, we chose eight rivers and lakes as the sampling locations, including three kinds of reclaimed water with different treatment processes and natural water. The morphology, structure and component characteristics of biofilms attached on the surface of aquatic plants and gravels in eight water bodies were evaluated. The results showed that the biofilm on the matrix surface were typical porous media with basic skeleton composed of inorganic particles, microorganisms and algae. The pores were filled with the viscous extracellular polymeric substances (EPS) secreted by microorganisms. The biofilms contained calcite, quartz, illite, alkali feldspar, dolomite, clinochlore, goethite and inorganic salt, and approximately 50 % of these compositions are calcite and quartz. The concentration of EPS was 20.78–500.44 μg/mL, and that of the gravel biofilms was less than that in aquatic plants by 18.1–75.3 %. In these three reclaimed waters, 4–7 kinds of PLFA (phospholipid fatty acid) were detected in aquatic plants biofilms, more than one or two kinds than in gravel biofilms. And the dominant PLFA were i15:0 and 18:0, the total contents of which were, respectively, 74.4, 62.9 and 85.9 % in the three kinds of reclaimed water. All biofilm samples contain major microorganisms such as Pseudomonas, Acinetobacter and Comamonas. This study is aimed to provide some support for assessing the health of river–lake ecosystem with biofilm indicator.  相似文献   

13.
Seleniferous agricultural drainage wastewater has become a new major source of pollution in the world. In the USA, large areas of farmland in 17 western states, generate contaminated salinized drainage with Se concentrations much higher than 5 μg/I, the US Environmental Protection Agency water-quality criterion for the protection of aquatic life; Se values locally reach 4200 wg/1 in western San Joaquin Valley, California. Wetland habitats receiving this drainage have generally shown Se toxicosis in aquatic birds causing high rates of embryonic deformity and mortality, or have indicated potential ecological damage.Results of our laboratory flow experiments indicate that nanofiltration, the latest membrane separation technology, can selectively remove > 95% of Se and other multivalent anions from > 90% of highly contaminated water from the San Joaquin Valley, California. Such membranes yield greater water output and require lower pressures and less pretreatment, and therefore, are more cost effective than traditional reverse osmosis membranes. Nanofiltration membranes offer a potential breakthrough for the management of Se contaminated wastes not only from agricultural drainage, but from other sources also.  相似文献   

14.
The dissolved ionic constitutents of groundwaters are,in part,a recored of the minerals and rocks in aquifers through which the water has flowed.The chemical composition and association of these major ions in groundwaters have been used to trace groundwater flow paths and sources,In general,the chemical compostion of water in carbonate-rock aquifers in dominated by calcium,magnesium,and bicarbonate,whereas sodium,chloride,and sulfate can be dominant ions in the water that comes from volcanic aquifers or clay minerals.Since the 1990‘s,we have dealt with the geochemistry of groundwaters from more than 100 springs and wells in southern Nevada and eastrn california ,USA for major solutes and trace elements.This paper compiles the hydrochemical data of major ions of these groundwaters.Based on major ion geochemistry,groundwaters from southern Nevada and eastern California can be classified as carbonate aquifer water,volcanic aquifer water,and mixing water (either mixing of cabonate and volcanic aquifer waters or mixing with local recharges),Piper and stiff diagrams of major ions have graphically shown the general chemical characteristics,classification,and mixing relationships of groundwaters from southern Nevada and eastern California.  相似文献   

15.
Current assessments of the role of atmospheric deposition in the declining health of aquatic ecosystems indicate that the atmosphere could account for as much as 30% to 40% of total external nitrogen loading to some coastal waters. All such assessments are uncertain and need to be refined. To focus attention on the problem as it affect eastern North American coastal waters, a series of interdisciplinary workshops has been conducted, bringing together scientists and regulators. The series started with a meeting at Mt. Washington, Maryland in 1994, with subsequent meetings at Warrenton, Virginia in 1995, and Raleigh, North Carolina in 1997. Although the workshops considered all nitrogen species, toxic chemicals, trace metals, precipitation chemistry, airborne aerosols, and supporting meteorological investigation, most of the discussion centered around the issue of nitrogen-species deposition. It was concluded that work is urgently needed to establish integrated monitoring stations to provide high quality deposition and watershed retention data within the catchment area to take spatial and temporal variability into account in atmospheric deposition models, to improve biogeochemical watershed models, especially from the perspective of biological utilization and cycling of deposited materials, to refine emissions inventories and projections on which scenario investigations are based, to enhance all ongoing data collection efforts, especially those related to specific process studies, and to improve spatial resolution by increasing the number of deposition measurement sites. An overall conclusion was that there must be a strong effort to include considerations of air pollution and atmospheric deposition in the water quality regulatory process. It was repeatedly emphasized that any new efforts should build on existing programs rather than risk new starts that compete with ongoing and already productive work.  相似文献   

16.
Sewage treatment station in oilfield needs a new process to meet the desired requirements. A new process was proposed to meet the discharge standards, which consisted of the following sub-processes: electrochemical treatment → coagulation treatment → integrated biochemical treatment of moving bed biofilm reactor and membrane bio-reactor → combined treatment process of macroporous adsorption resin. Electrochemical treatment included 5 electrolytic cells, total volume of which was 10 L. The PFS was chosen as the coagulants in the coagulation treatment, and the removal rate of COD could reach 66% when the dosage of PFS was 500 mg/L. The biochemical treatment consisted of anoxic tank, aerobic tank and membrane zone, and the removal rate of COD was about 55–70% when HRT was 12 h. SD300 resin was chosen as the best adsorbent in the treatment using macroporous adsorption resin. In addition, the effluent COD after coagulation treatment process becomes about 180 mg/L, the effluent COD after biological treatment becomes about 50 mg/L, and the last effluent COD with the macroporous adsorption resin becomes about 20 mg/L. The three-dimensional fluorescence spectrum was used to analyze the differences in types of organic matters in water samples between the raw water and the treated one. The results demonstrated that the new process meets the needs of wastewater treatment.  相似文献   

17.
A combined ABR–MBR process consisting of an anaerobic baffled reactor (ABR) combined with an aerobic membrane bioreactor (MBR) treating municipal wastewater was investigated at controlled pH range 6.5–8.5 and at constant temperature 25 ± 1 °C. Total nitrogen (TN), ammonia (NH4 +–N), total phosphorus (TP), and chemical oxygen demand (COD) removal performances were evaluated by analyzing the mechanism for efficient nutrient removal. The results showed that the average removal rates of COD, NH4 +–N, TN, and TP reached 93, 99, 79, and 92 %, respectively, corresponding with the COD, NH4 +–N, TN, and TP effluent of 24 (18–31), 0.4 (0–0.8), 10.6 (8.8–12.9), and 0.31 (0.1–0.5) mg/L under the operational condition of hydraulic retention time (HRT) 7.5 h, recycle ratio 200 %, and dissolved oxygen 3 mg/L. The MBR enhanced NH4 +–N, TN, and TP removal rates of 13, 10, and 18 %, respectively, and the membrane retention reduced TP 0.17 mg/L. The process was able to maintain a stable performance with high-quality effluent. Analysis of the results by fluorescence in situ hybridization showed that the abundance of ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, and phosphorus accumulating organisms as percentages of all bacteria in each compartment was stable. The enriched microorganisms in the system appear to be the main drivers of the process efficient for nutrient removal.  相似文献   

18.
新型SBR工艺处理生活废水的研究   总被引：2，自引：0，他引：2  
新型SBR工艺是在传统SBR反应器中加一隔板,将反应器从空间上分成上下两个区域,上面是好氧区,下面为缺氧厌氧区。实验通过水力停留时间和上下区域体积比对脱氮除磷效果影响的研究,确定该工艺的最佳运行工况和反应器内挡板位置;同时与传统SBR工艺进行对比实验研究。结果表明,进水60 m in,曝气240 m in,沉淀30 m in,排水15 m in,闲置15 m in;上下区域体积比为1∶1时脱氮除磷效果最佳,TN和TP去除率达到88.7%和78.4%,其效果均好于传统SBR工艺。  相似文献   

19.
宋刚  张伯友  王新明 《矿物岩石》2004,24(2):117-120
利用RAD7便携式测氡仪和NR-67A型连续测氡仪测量了广东省一些温泉宾馆室内外氡浓度。从无人入住的宾馆房间内氡浓度的变化来看，土壤氡的渗入是底层房间氡的主要来源。当在浴室内使用温泉水洗浴时，客房内平均氡浓度水平比没有用温泉水时高出10．9％～813％，浴室内氡浓度比没有用温泉水洗浴时高出13．8％～489％。宾馆室内使用温泉水有较高的氡转换系数。某些宾馆室内氡浓度超标。可能对宾馆工作人员造成潜在健康危害，应采取一些管理措施或技术手段降低其暴露水平。  相似文献   

20.
In recent years, reclaimed wastewater as a water source for urban artificial landscape rivers is being rapidly developed in some coastal cities with limited water resource available in China. However, eutrophication occurs more often in the landscape waterbody with reclaimed wastewater than in natural rivers and lakes. The study of restoration and reconstruction of macrophytes, especially the submerged aquatic vegetation, is essential to inhibit eutrophication of reclaimed wastewater. This study investigated the seasonal variation of biomass of Ruppia maritima in the artificial landscape river using reclaimed wastewater as the only water source in Tianjin, China. It was found that there were two seasonal growth peaks of Ruppia maritima each year in the coastal reclaimedwastewater. The contents of nitrogen and phosphorus of Ruppia maritima varied with the season.  相似文献   

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