Strategy for olive mill wastewater treatment and reuse with a sewage plant in an arid region.

This study was conducted to evaluate the treatability of OMW (olive mill wastewater) with sewage and sewage sludge, which could supplement nutrients and microbes required for OMW treatment and reduce its possible toxicity. The amount of OMW added to an aeration tank was based on the loading difference between the designed and actual COD loads, while the amount added to anaerobic digestion for energy recovery was determined by CH4 production. The COD removal efficiencies were 70-85% for both systems. Compost of OMW with dried sewage sludge also showed a similar temperature profile without OMW addition. This strongly suggested that OMW can be treated at a sewage plant without pretreatment and the treated effluent can be reused in irrigation for an arid region.     

Influence of sewage from different water treatment plants in the Cracow Region (Poland) on early developmental stages of water snails

The cocoons of the great pond snail, Lymnaea stagnalis (L.), and the great ramshorn, Planorbarius corneus (L.) were exposed to mechanically and biologically treated sewage from different water treatment plants in the region of Cracow (southern Poland). The control group consisted of snails from the same cocoon as the experimental snails. Mineral water and pond water from Zabierzów Bochenski (near Cracow) were used for the control groups. We found that mechanically treated sewage from the Plaszów sewage treatment plant was highly toxic (100% embryo lethality). The toxicity was reduced after mixing sewage with the control water (25% solution). However, in this group, the development of embryos was slower than in the control. No toxicity was observed in the biologically treated sewage from the same plant. The sewage from the Myslenice plant (mechanical treatment) was also very toxic (100% lethality), but this toxicity disappeared after keeping the sample at room temperature for 1 year. Water from the Vistula River was not toxic.     

Municipal wastewater treatment with pond-constructed wetland system: a case study.

The performance of a pond-constructed wetland system in the treatment of municipal wastewater in Kiaochow city was studied; and comparison with oxidation ponds system was conducted. In the post-constructed wetland, the removal of COD, TN and TP is 24%, 58.5% and 24.8% respectively. The treated effluent from the constructed wetland can meet the Chinese National Agricultural and Irrigation Standard. The comparison between pond-constructed wetland system and oxidation pond system shows that total nitrogen removal in a constructed wetland is better than that in an oxidation pond and the TP removal is inferior. A possible reason is the low dissolved oxygen concentration in the wetland. Constructed wetlands can restrain the growth of algae effectively, and can produce obvious ecological and economical benefits.     

苏州市东山镇池塘养蟹面源污染现状及控制

结合全国污染源普查活动,以苏州市养殖老区东山镇养殖池塘为典型,调查其现行养殖模式、经济效益、养殖污染状况。调查结果显示,东山镇现有养殖面积为2 253.33 hm2,主养品种为河蟹。1个养殖周期中,养殖池塘通过沟渠排入外界的TN、TP含量分别平均为21.25 kg/hm2、2.34 kg/hm2;密度为9 000只/hm2的低密度养殖池外排的TN含量为16.79 kg/hm2,而无TP排出。分析苏州地区池塘养殖产生水环境污染的主要原因,从池塘管理体制改革、科学生态养殖技术及养殖尾水处理等方面探讨池塘养殖污水零排放技术,为苏州市养殖业面源污染的控制提供对策和措施。     

适用于河流治理的地面廊道污水处理系统的设计

地面廊道污水处理系统类似于人工湿地技术，其优点在于该系统应用于污染河流的治理时，对河流地形适应性非常强；另外系统四周不透水的墙体结构使整个廊道起着氧化塘的作用，并且沿坡降由好氧塘逐渐过渡到厌氧塘。本文重点介绍该处理系统的设计，主要包括廊道的选址．水生植物的选择．廊道最佳长度及运行参数的确定。     

Reducing Water Use for Animal Production through Aquaculture

Animals fed formulated diets indirectly consume large quantities of water. Globally, about 1.2 m³ of water is needed to produce 1 kg of grain used in animal feeds. Cattle in feedlots consume about 7 kg of feed concentrate to gain 1 kg in weight. For pigs this is close to 4 kg and for poultry slightly more than 2 kg of concentrate. Fish or crustaceans require less than 2 kg of grain concentrate for each kg produced, making them the most efficiently producing animals in terms of feed-associated water use. Non-feed-associated water use can also be considerable, and a comparison was made in total water use between aquatic and terrestrial animals. On-farm water use for terrestrial animals, including drinking, but excluding water for cooling animals or cleaning their sheds is only 1% of feed-associated water use. However, on-farm water use in aquaculture can be very high, attaining values of up to 45 m³ per kg produced in ponds. Intensification of aquaculture reduces on-farm water use per kg product, and only intensive aquaculture production systems are equally water-efficient as terrestrial animal farming systems. Within existing aquaculture pond systems reductions in water use can be achieved through (1) selection of feed ingredients that need little water to be produced; (2) enhancement of within-system feed production through periphyton-based technology; and (3) integration of aquaculture with agriculture. Still, these approaches will not make pond aquaculture more water-efficient than terrestrial animal production systems. That can only be attained in recirculating aquaculture systems and systems producing fish as a by-product of wastewater treatment. Currently, the most promising approach is to concentrate on further development of brackish and marine aquaculture, as such systems use small or negligible amounts of non-feed-associated fresh water.     

Energy and nutrient recovery from sewage sludge via pyrolysis.

Energy recovery and nutrient reuse from sewage sludge has traditionally been achieved via anaerobic digestion/power generation with land application of the biosolids. By contrast, thermal processes such as pyrolysis have typically been used only for energy recovery. One such technology has demonstrated at commercial scale that all of the energy in sludge can be beneficially recovered and reused. No attempt was however made to recover and reuse sludge nutrients. There are many potential benefits of using pyrolysis for both energy and nutrient recovery. Firstly, unlike digestion, the principal energy product is oil, which can readily be stored and used when required, ensuring that energy recovery is maximised. Secondly is that the sludge nutrients are recovered in the pyrolysis char. Laboratory soil incubation studies using char from the Subiaco demonstration plant were conducted over an eight-week period to confirm nutrient availability. Results from this study showed that the phosphorus in the char is plant available although the nitrogen was insoluble. Based on these results it appears that there is potential to use pyrolysis as an effective means to recover and reuse both the energy and the very valuable phosphorus present in sewage sludges.     

基于层次分析法的水源地上游农村生活污水处理技术综合性能评价

通过分析影响农村生活污水处理技术综合性能的相关因素,应用层次分析法(AHP)建立了包含1个目标层、3个准则层和12项指标的水源地上游农村生活污水处理技术综合性能评价指标体系,并确定了各指标权重。对水源地上游8类农村生活污水处理技术性能进行综合评价的结果表明,采用组合工艺的处理技术综合性能优于采用单项工艺的技术;小型一体化污水处理装置、土地处理系统、小型人工湿地的综合性能优于生物接触氧化池、净化沼气池和稳定塘。生物+生态组合工艺处理技术比较适合于水源地上游农村生活污水处理应用。针对特定地区,可参考基于层次分析法的技术综合性能评价结果,并综合考虑当地自然、经济和社会条件等因素,因地制宜选择先进适用的农村生活污水处理技术。     

Feasibility of a constructed wetland and wastewater stabilisation pond system as a sewage reclamation system for agricultural reuse in a decentralised rural area.

The performance of a constructed wetland (CW) and wastewater stabilisation pond (WSP) system for sewage reclamation and paddy rice irrigation in a decentralised rural area was examined using a feasibility study. The CW was satisfactory for sewage treatment, with good removal efficiency even in the winter period, but the effluent concentration was relatively high in the winter period owing to the high influent concentration. The CW effluent was further treated in a WSP and the WSP effluent was considered safe for crop irrigation with respect to sewage-borne pathogens. Reclaimed water irrigation did not adversely affect the yield of rice; on the contrary, it resulted in an approximately 50% greater yield than in controls. The chemical characteristics of the soil did not change significantly during the experimental period of irrigation with reclaimed water. In the winter, CW effluent could be stored and treated in a WSP until the spring; the water could then be discharged or reused for supplemental irrigation during the typical Korean spring drought. Overall, sewage treatment and agronomic reuse using a CW-WSP system could be a practical integrated sewage management measure for protecting receiving water bodies and overcoming water shortages in decentralised rural areas.     

基于EFDC模型的尾水回用于城市景观水体优化计算

以昆山市内蓬朗污水处理厂深度处理后的尾水回用于城市景观水体夏驾河为例,以环境流体动力学模型(environmental fluid dynamic code,EFDC)构建的夏驾河三维非稳态水量模型为基础,考虑经济、社会、环境等多方面的效益,构建目标函数,研究6种设计情景下尾水回用的综合效益,确定污水处理厂尾水回用的最佳运行方案。结果表明,从经济、社会、环境效益最大化的角度出发,昆山市夏架河尾水回用最优方案为:出水口选为距太仓塘4.5 km处,排水方向为吴淞江,回用流量为3.4万m3/d。尾水回用于景观水体可以有效改善水体交换,蓬朗污水处理厂尾水入河位置及回用量流量直接影响夏驾河换水周期以及夏驾河水质的好坏。     

蘑菇湖水库水环境现状及保护对策

对蘑菇湖水库主要污染源和水库水质现状进行调查评价,分析表明蘑菇湖水库污染严重,已失去养殖功能。为减少水库纳污量,控制水体进一步受到污染,提出治理措施和建议:石河子造纸厂是水库的主要点污染源,应修建氧化塘,废水处理后,达标排放;石河子市尽快建立污水处理场,对排污管网的污水进行处理,达到污水一级排放标准后,合理调度,减少水库纳污量。     

生物-生态修复技术在景观污染水体治理中的应用

采用生物治理与生态修复技术对昆山市环城北路景观池塘水体因富营养化、流动性差等引起的黑臭现象进行治理。治理后TN、TP的去除率均超过85%,水质达国家地表水Ⅲ类水标准,水体透明度达1.28 m,生物多样性增加,景观效果显著改善。结果表明,生物-生态修复技术对没有或仅有少量污水排入的受污染景观水体较为适宜。     

用氧化塘—浮石床湿地系统处理暖寒季低污染河水

在滇池流域构建氧化塘-浮石床湿地复合系统对暖季与寒季的城市低污染河水开展了净化效能研究。结果表明:该系统可通过小幅调节流量来有效净化暖季与寒季低污染河水。塘与湿地的水力负荷分别为0.22、0.37m3/(m2.d)时系统对暖季低污染河水具有较高的处理效率,各污染物的平均去除率分别为CODCr75%、TP 93%、TN 64%、NH4+-N 87%。塘与湿地的水力负荷分别为0.17、0.29 m3/(m2.d)时系统对寒季低污染河水具有较优的处理效果:各污染物的平均去除率分别为CODCr72%、TP 89%、TN 53%、NH4+-N 73%。系统出水均符合GB18918-2002的一级A排放标准。系统在暖季对低污染河水中污染物的去除速率明显高于寒季。     

不同填料强化生态浮床对淡水养殖水体的净化效果

人工填料强化生态浮床是近年来发展起来的一种新兴生态工程修复技术。选取3种不同类型的人工填料与挺水植物组合,分析其对高磷浓度养殖水体和上海市养殖池塘水体的净化效果。结果表明,在高磷浓度(2.36~3.42 mg/L)养殖水体中,人工填料强化生态浮床对TN、TP、COD的平均去除率分别为34.9%,12.2%,26.1%,且3组系统之间差异不明显。在上海市养殖水体平均浓度条件下,3组系统对TN和TP的去除能力为:立体弹性填料强化生态浮床＞组合填料强化生态浮床＞生物绳填料强化生态浮床,立体弹性填料强化生态浮床对TN和TP的去除率分别为83.9%和69.3%;3组系统对COD和NH₄⁺-N的去除率均在70%以上。因此,立体弹性填料强化生态浮床可以考虑应用于上海市淡水养殖池塘水体的生态修复工程。     

太湖流域某养殖池塘水平衡分析和水生态模拟

为解决传统池塘养殖产生的环境污染问题，应用水生态模型对养殖池塘水生态环境进行模拟。以太湖流域 某养殖池塘为例，通过水量平衡分析得到具体补排水时间序列，输入 AQUATOX 水生态模型软件进行建模，经过 率定验证后进行控制模拟，针对投饵率对水质与养殖品之间的相互影响规律进行探讨。结果表明：基于降雨-水位 的补排水识别方法能弥补具体补排水量的测量空白；饵料对研究池塘水质影响较大，在 1%~7% 的投饵率梯度中， 随着投饵率的增加，TP、TN 和氨氮质量浓度整体上大幅增加；以养殖品安全质量浓度为界，在 1%~7% 的投饵率 梯度内养殖品产量随氨氮质量浓度的增加呈现先增后减的趋势。该研究建立的水生态系统模型模拟效果较好， 综合考虑保持良好的水生态环境与经济成本，该池塘养殖中的建议投饵率为 2.5%~3.0%。     

基于两相流的氧化沟推流器分布特性研究

针对氧化沟污水处理技术中可能存在的能耗大、污泥淤积的问题,将活性污泥的黏度和沉降速率通过用户自定义函数导入Fluent软件,对某污水处理厂的标准氧化沟进行水-活性污泥两相流数值计算,得到氧化沟中推流器功率、速度分布情况及污泥分布情况,并对其进行分析比较,选出最优电机功率及推流器分布。对氧化沟内流场特性进行深入分析,将数值模拟及试验测得断面流速进行比较,结果表明各测点数据吻合程度较好,因此认为数值模拟能够较好地预测出真实流场中各点的流速,且速度死区率大的区域污泥质量浓度一般较高。     

Aerobic granular sludge technology: an alternative to activated sludge?

Laboratory experiments have shown that it is possible to cultivate aerobic granular sludge in sequencing batch reactors. In order to direct future research needs and the critical points for successful implementation at large scale, a full detailed design of a potential application was made. The design was based on the laboratory results, and two variants of a full-scale sewage treatment plant based on Granular sludge Sequencing Batch Reactors (GSBRs) were evaluated. As a reference a conventional treatment plant based on activated sludge technology was designed for the same case. Based on total annual costs both GSBR variants proved to be more attractive than the reference alternative (7-17% lower costs). From a sensitivity analysis it appeared that the GSBR technology was less sensitive to the land price and more sensitive to a rain weather flow (RWF). This means that the GSBR technology becomes more attractive at lower permissible RWF/DWF ratios and higher land prices. The footprint of the GSBR variants was only 25% compared to the reference. However, the GSBR with primary treatment only cannot meet the present effluent standards for municipal wastewater in The Netherlands, mainly because of a too high suspended solids concentration in the effluent. A growing number of sewage treatment plants in the Netherlands are going to be faced with more stringent effluent standards. In general, activated sludge plants will have to be extended with a post treatment step (e.g. sand filtration) or be transformed into Membrane Bioreactors. In this case a GSBR variant with primary treatment as well as post treatment can be an attractive alternative.     

污泥堆肥土地利用对土壤环境及高羊茅特性的影响

结合北京市污泥堆肥土地利用现状．研究了污泥堆肥对土壤环境及高羊茅（Festuca arundinace。）的影响。旨在为北京市污泥堆肥用于高羊茅园林生产提供理论依据,促进资源再利用。研究结果表明．施用污泥堆肥增加了高羊茅栽植小区土壤养分含量,特别是土壤中有机质含量增加明显,与空白对照相比增加了43．9％～73．2％,对土壤养分状况具有一定的改良效果;施用污泥堆肥后,高羊茅栽植小区土壤中重金属含量虽有不同程度的增加。但均远低于相关标准限值．且土壤重金属污染综合指数小于土壤安全限值0．7．表明种植小区土壤未受到重金属污染：施用污泥堆肥对高羊茅生长具有一定的促进作用．与空白对照相比．高羊茅总生物量增长率为16．7％～50．0％。综合分析试验结果,确定污泥堆肥用于高羊茅的适宜施用量为2kg／m^2。     

Integrated modelling of nitrate loads to coastal waters and land rent applied to catchment-scale water management.

The EU Water Framework Directive (WFD) requires an integrated approach to river basin management in order to meet environmental and ecological objectives. This paper presents concepts and full-scale application of an integrated modelling framework. The Ringkoebing Fjord basin is characterized by intensive agricultural production and leakage of nitrate constitute a major pollution problem with respect groundwater aquifers (drinking water), fresh surface water systems (water quality of lakes) and coastal receiving waters (eutrophication). The case study presented illustrates an advanced modelling approach applied in river basin management. Point sources (e.g. sewage treatment plant discharges) and distributed diffuse sources (nitrate leakage) are included to provide a modelling tool capable of simulating pollution transport from source to recipient to analyse the effects of specific, localized basin water management plans. The paper also includes a land rent modelling approach which can be used to choose the most cost-effective measures and the location of these measures. As a forerunner to the use of basin-scale models in WFD basin water management plans this project demonstrates the potential and limitations of comprehensive, integrated modelling tools.     

北京市农村污水处理方法及效果

为研究农村污水特点,针对性选择处理工艺,对北京市通州、房山、昌平、怀柔、密云等5个区县的4种类型村庄的污水结构、用水量、污水排放量、污染物浓度进行调查研究,同时对6种污水处理工艺进行污染物去除率、建设运行费用、占地面积进行调查研究。结果显示:京郊农村污水主要由厨房污水、生活洗涤污水、冲厕污水、养殖污水组成;污水排放规律为夏季大、冬季小,污水污染物种类多,城乡结合部村水质最差,山区村水质最好。综合分析表明,MBR、MBR+土地渗滤、A/O+土地处理系统工艺适宜在平原地区经济条件较好的村庄及城乡结合部村庄使用;人工湿地工艺适宜在面积大、经济条件较差、对出水水质要求不高的平原区村庄使用;山区村庄可考虑采用厌氧生物滤池处理技术;民俗旅游村等经济条件较好、出水水质要求较高的村镇地区可考虑采用MBR工艺及一些高效组合工艺。