Helsinge sludge reed bed system: reduction of pathogenic microorganisms.

Reduction of pathogenic bacteria: Salmonella, enterococci and Escherichia coli was investigated using the sludge reed bed system. The system at Helsinge was established in 1996 and has a capacity of 630 tonnes dry solids per year and consists of 10 basins. Since 2000 the individual basins have been subjected to an average area-specific loading rate of 46-56 kg dry solids/m2/year. The total sludge residue height in April 2006 was approximately 1.40 m. The sludge (approximately 0.5-0.8% dry solids), with which the individual basins were loaded, contained a large number of bacteria. Salmonella, enterococci and E. coli were found in the sludge in the following quantities: 10-300/100 g (wet weight), 7,000-25,000 CFU/g (wet weight) and 800,000-10,000,000 CFU/100 g (wet weight), respectively. The analysis of the reduction in pathogens in the sludge residue through a period of 3-4 months after the last loading indicated that the pathogen content was reduced down to < 2/100 g (Salmonella), < 10 CFU/g (enterococci) and < 200 number/100 g (E. coli). For enterococci and E. coli the reduction was approximately log 5 and log 6-7, respectively. In the same period the sludge residue achieved a dry solids content of approximately 20-35%.     

Mineralisation of hazardous organic compounds in a sludge reed bed and sludge storage.

Linear alkylbenzene sulphonates (LAS) and nonylphenolethoxylates (NPE) may be detrimental to the environment if spread in inappropriately large concentrations. Mineralisation of LAS and NPE in mesophilic digested sludge was observed during a 9-month monitoring programme where three separate treatment methods were investigated. Sludge was treated in a sludge reed bed under aerobic conditions, by storage in a container under anaerobic conditions, and by storage in a sludge pile turned over mechanically at intervals to improve the oxygen influx. Treatment in a sludge reed bed was shown to be effective. Mineralisation of 98% of LAS and 93% of NPE was observed. Only limited mineralisation occurred on the surface of the sludge stored in a container. A reduction of LAS and NPE of 90% and 43%, respectively, was observed in the sludge which was stored in a pile and frequently turned.     

Exceeding tertiary standards with a pond/reed bed system in Norway.

At Vidar?sen in Norway sewage from a community consisting of 160 people, including a dairy, a food processing workshop, a bakery and a laundry is treated using a pond/reed bed system. The system consists of sludge settlement, pre-treatment surface/vertical-flow constructed wetlands, a 5 m deep enhanced facultative pond, three stabilization ponds, a planted sand filter and finally two horizontal-flow constructed wetlands filled with lightweight aggregate (Filtralite-P). The enhanced facultative pond and the primary stabilization pond are equipped with Flowform-cascades, which provide year-round aeration, rhythmical treatment and mixing of wastewater in the ponds. Treatment performance during the first five years has been high and unaffected by harsh winter conditions. Average phosphorus discharge from the system is 0.25 mg/l with total nitrogen 4 mg/l, total organic carbon (TOC) 5 mg/l and thermo-tolerant coliforms < 100/100 ml. The system is ecologically diverse and supports abundant populations of higher aquatic life such as ducks, amphibians and carp.     

Dewatering sludge originating in water treatment works in reed bed systems

The dewatering process of the liquid water works sludge was examined in a trial with a series of six trial beds, each 20 m2. These were monitored from April 2008 to June 2010. It is possible to get the vegetation to grow in ferric sludge (approximately 300,000 mg Fe/kg dry solid, pH 7,7). It has not been necessary to use fertilizer. The influence of the loading programs (15-50 kg dry solid/m2/year) was tested with 1-5 days of loading and 35-55 days of rest. It is possible to drain and treat ferric sludge. Generally the dewatering profile is a peak with a maximum over 0.015-0.025 L/s/m2. The times for dewatering of 6-12 m3 are approximately 15 h and over 90% of the load is dewatered in that period. The dry solid (0.16-0.20%) in the sludge has been concentrated approximately 200 times. The dewatering phase results in ferric sludge with 30-40% dry solid which cracks up very quickly. The volume reduction is over 99%. The trend shows that the main volume of reject water has a turbidity level below 5 NTU even in the loading periods.     

Optimising the performance of a lab-scale tidal flow reed bed system treating agricultural wastewater.

A gravel-based tidal flow reed bed system was operated with three different strategies in order to investigate its optimal performance for the treatment of a high strength agricultural wastewater. According to the three strategies, individual reed beds were saturated and unsaturated with the wastewater for different periods while reasonably stable hydraulic and organic loadings were maintained. Experimental results demonstrated that the system produced the highest pollutant removal efficiencies with a relatively short saturated period and long unsaturated period, highlighting the importance of oxygen transfer into reed bed matrices during the treatment. Significant removals of some major organic and inorganic pollutants were achieved under all three operational conditions. Nitrification was not the major route of ammoniacal-nitrogen removal when the system was under high organic loading. Due to the filtration of suspended solids and the accumulation of biomass, gradual clogging of the reed bed matrices took place, which caused concerns over the long-term efficiency of the tidal flow system.     

Six years of operation of a fluidised bed reactor for denitrification.

At Himmerfj?rden wastewater treatment plant, a fluidised bed reactor for nitrogen removal has been operated since 1997. Despite its small footprint, the system enables a far-reaching nitrogen removal. The current nitrate reduction in the reactor is 95%. The reduction of total nitrogen at the wastewater treatment plant is 80-90% at normal operation. The concentration of nitrate in the effluent is easily controlled by changing the dose of carbon. As part of a series of full-scale experiments, the plant has, for the last two years, been operated without denitrification for a couple of months during spring/summer, in order to benefit a favourable N/P-ratio in the recipient and to counteract the growth of nitrogen fixing blue-green algae, When resuming the dosage of carbon, full denitrification was re-established in about two weeks. Important factors to take into consideration when operating the fluidised bed reactor are the abrasive characteristics of the carrier material (sand), the increased concentration of suspended solids in the effluent, and the importance of a suitable N/P-ratio in the influent, as lack of phosphorus might cause an uncontrolled microbiological growth.     

UNITANK系统不同运行方式下污泥膨胀的特点与控制

由于连续进水、连续出水的UNITANK系统在流态上接近完全混合,基质浓度梯度大大降低,这对于控制污泥膨胀是较为不利的。试验表明,UNITANK系统的单级好氧处理系统在较低或较高的有机负荷下易发生污泥膨胀,在中等负荷下若使得进水池溶解氧充足则可控制污泥膨胀的发生;脱氮除磷处理系统由于进行缺氧搅拌的边池可起到缺氧选择器的作用,其不发生污泥膨胀的有机负荷限值范围较单级好氧处理系统大;与SBR系统相比,UNITANK系统控制污泥膨胀的能力相对较弱。     

Aspects of design, structure, performance and operation of reed beds--eight years' experience in northeastern New South Wales, Australia.

Reed beds (horizontal subsurface flow constructed wetlands) have been employed as secondary treatment devices in on-site and decentralised wastewater management systems in the northeast of the Australian state of New South Wales (NSW) for over a decade. This paper summarises some of the practical and research findings that have come to light in that time. Experience with various aspects of reed bed structure is discussed. A study of the evaporative performance of four small beds planted with Phragmites australis yielded an annual crop factor of 2.6. A total of 28 studies on reed beds treating a variety of commonly encountered wastewater streams yielded the following mean pollutant removal efficiencies: total suspended solids (TSS) 83%, biochemical oxygen demand (BOD) 81%, total nitrogen (TN) 57%, total phosphorus (TP) 35% and faecal coliforms (FC) 1.9 logs. The reed bed is becoming the preferred on-site technology for removing TN and BOD and polishing TSS from primary settled domestic wastewater. Sizing beds for a residence time of approximately five days has become standard practice. A study of six reed beds found six different species of earthworm present, mainly Perionyx excavatus (Indian Blue). A mesocosm experiment subsequently showed that the worms were translocating clogging material from the substrate interstices to the surface of the bed thereby indicating a possible method for prolonging reed bed life.     

溶解性有机质对低影响开发设施运行影响的研究进展

低影响开发(LID)设施在治理城市内涝和径流污染中发挥重要作用,在我国海绵城市建设中应用广泛。溶解性有机质(DOM)是一类具有较强的吸附、络合作用的溶解态物质,其质量占比高达径流污染物的50%以上。为阐明DOM对LID设施运行的影响,结合国内外研究现状及进展,综述DOM自身性质及其对LID设施中重金属(HMs)、持久性有机物(POPs)的归趋以及对微生物环境的影响,指出DOM会通过吸附、络合与HMs、POPs作用,造成LID设施填料吸附位点饱和、填料堵塞、微生物相对丰度(RAs)改变等。本研究旨在为LID设施设计和运行优化提供参考。     

农村供水工程主要设施运行管理要点

"十三五"时期,农村饮水安全进入全面巩固提升阶段,聚焦脱贫攻坚,重点健全完善工程良性运行机制,以强化水质保障为核心,全面提升农村饮水安全保障水平。从工程运行的实际出发,提出工程各环节关键设施的运行管理要点,加强农村供水设施的运行管理,保证工程可持续运行,确保扶贫目标的实现,保障农村居民的饮水安全。     

水利设施防雷接地系统施工质量通病及其控制

确保水利工程大型设备的安全运行,尤其是在雷雨季节的正常运行,防雷接地的施工质量尤为重要.很多水利工程的临时性大型设备由于考虑时间及成本等因素,在安装时往往忽略防雷保护.在水利施工中,如果大型设备接地不良,不但影响工程设备的安全运行,而且会造成较大的经济损失,甚至会引起人身伤害事故.必须吸取防雷接地施工质量事故的深刻教训.浅析了设备安装前接地系统施工的质量通病及其控制.     

Intermittent vs continuous operation of upflow anaerobic sludge bed reactors for dairy wastewater and related microbial changes.

This work compares continuous vs intermittent UASB reactors inoculated with flocculent sludge for the treatment of dairy effluents. The effects of effluent recirculation on the performance of intermittent reactors were assessed as well as the differences in specific methanogenic activity (SMA) with different substrates for the biomass from continuous and intermittent UASB reactors. Compared to the continuous operation the intermittent operation resulted in higher methanization of the removed COD (64-78% and 65-88%, respectively) whilst the effluent recirculation presented beneficial effects when applied during the stabilization period and was clearly detrimental when applied during the feed period of the intermittent operation. The SMA tests showed that the intermittent operation causes a shift in the microbial populations towards a better adaptation for the degradation of complex substrates confirmed by the meaningfull contribution of methane production through a pathway other than acetoclastic methanogenesis observed in the biomass taken from intermittent UASB reactors.     

三门峡水库运用方式对潼关高程的影响

三门峡水库修建后，潼关处于水库库区，河床淤积抬高。抬高过程与三门峡水库的运用方式及泄流规模密切相关。本文从实测资料入手，主要分析了三门峡水库控制运用以来，潼关河床高程的变化。非汛期水库高水位运行时间长，潼关河床淤积抬高，汛期冲刷历时短，溯源冲刷发展不到潼关，潼关河床得不到有效冲刷，且不利于汛期输沙，都是潼关河床抬高的主要原因。     

清原县农田水利工程运行管理问题与对策

位于辽东山区的清原县水资源较丰富,农田水利工程建设的开始时间较早,运行时间较长,这些农田水利工程规模大小不等,数量众多,地理位置分散,结构形式多样,在日常运行管理中存在养护不到位、资金落实困难、灌溉水利用效率低等问题,只有解决了这些问题才能提高粮食产量,增加农民人均收入。     

湿法脱硫运行与维护中存在的问题

研究了某发电公司600MW超临界燃煤机组应用石灰石-石膏湿法烟气脱硫中遇到的几个实际问题,重点讨论分析了粉尘浓度、吸收塔溢流、工艺设计等对脱硫系统运行与维护所产生的影响,对脱硫系统运行中存在的问题提出了几项整改措施。     

分散式农村生活污水处理设施运营模式探讨

分散式农村生活污水处理设施点多面广,缺乏有效的管理模式,无法保障设施的正常运行和出水的稳定达标,成为农村水环境整治的难题。在分析我国农村生活污水水质及排放特征的基础上,针对分散式农村生活污水处理设施在运行管理中存在的问题,提出了第三方运营管理模式。结果表明,这种模式可以有效降低成本,提升管理效率,可以有效地解决设施长效管理问题;第三方运营管理模式是分散式农村生活污水处理设施运营管理深入发展的必然趋势。     

我国西部地区污水处理设施现状及问题探讨

对我国西部四川、陕西、云南等地区的若干代表城市(镇)污水处理现状及存在问题进行了调研,调研结果表明,先进的污水处理工艺在西部有一定的适用性.同时发现这些地区污水处理在管网建设、工艺选择、设计水质水量的确定、污水处理成本及收费、污泥处理、污水再生利用、臭气处理等方面存在一定的问题,并针对上述问题提出一些对策建议.     

Sludge production and management processes: case study in China.

In 2010, the sewage sludge production rate will be 178,500 t dried solids (ds) for Beijing and 294,000 t-ds for Shanghai, respectively. Beijing adopts a centralized system to stabilize 78% of her sludge in three rural Stabilization Centres. Aerated composting technique will be used. Shanghai on the contrary decentralizes the management plan to treat the sludge on site. Diverse treatment trains, such as aerobic/anaerobic digestion, drying, incineration, and composting will be applied. Production rate, treatment plan, and the associated costs, energy consumption, carbon dioxide emission, and risk assessment for heavy metals and pathogens on human health were evaluated in this report for sludges yielded in Beijing and Shanghai, China.     

北京村镇污水处理设施运行管理机制探讨

为了保护水资源,北京近年来大力开展农村地区的污水治理,建成了一批村镇污水处理设施.目前村镇污水处理设施的管理水平和运行状况存在参差不齐的现象,通过分析其中存在的问题,提出了具有可操作性的运行管理模式和对策.