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1.
污水处理量的增加产生了更多的剩余污泥,导致污泥处理处置费占污水厂运行费的比例在不断增加[1].污泥减量化是该领域近年的研究重点[2],国内外采用臭氧对污泥进行减量的研究较成熟[3-4].但是污泥破解液中碳、氮和磷的释放是否会对污水厂的出水产生影响,将关系到臭氧减量化技术能否应用在污水厂的实际运行中.  相似文献   

2.
污泥间接干化产生的恶臭及挥发性有机物特征   总被引:1,自引:0,他引:1  
正随着城市发展,污水处理量大幅提高,城市污水处理厂污泥产量也急剧增加,使污泥的处理处置成为亟待解决的问题.利用水泥厂煅烧设备处理污水处理厂污泥,可实现污泥处置的无害化、减量化以及资源化[1].在焚烧处置之前,须先将污泥进行干化处理,使其含水率达到焚烧要求.湿污泥干化过程中,由于部分有机物的转化与挥发,干化尾气中存在恶臭及挥发性有机污染物.北京水泥厂有限责任公司的处置污水处理厂污泥工程是我国首个利用水泥窑余热干化处置污水  相似文献   

3.
不同干燥处理对城市污泥物理性质和农业利用的影响   总被引:2,自引:0,他引:2  
城市污泥农用正在成为世界各国处置污泥的主要方式之一,但干燥后的污泥通常结块程度高,硬度大,较难粉碎,对污泥的后续利用产生影响.试验设置了露天、棚内浇水和棚内不浇水等三个不同的污泥干燥处理,试验结果表明,露天状态处理干燥后的污泥要明显松散,结块程度较低;露天状态处理干燥后,粒径在5~10 mm和小于5 mm的污泥颗粒含量要显著高于棚内浇水和棚内不浇水处理,且露天处理干燥后污泥中水稳性团聚体所占比例最大,小于0.001 mm的粒级(粘粒)所占比例最小,不易造成土壤板结.因此,露天处理干燥后的城市污泥对农用较为有利.  相似文献   

4.
污泥处理热干燥工艺的研究进展   总被引:3,自引:0,他引:3  
介绍了国外污泥热干燥工艺的现状和干燥设备的类型,阐述了热干燥方法,包括对撞流干燥、过热蒸汽干燥、燃气红外辐射干燥、间壁式热干燥和流化干燥等,及其在污泥干燥中的应用原理和发展。并分析了污泥干燥处理技术综合利用的几种途径和发展趋势,认为污泥热干燥技术拓展了污泥的处置手段,为污泥的安全、可靠利用与处理提供了保障。  相似文献   

5.
城市污泥植物处理系统与污泥中转处理场建设   总被引:4,自引:0,他引:4  
目前城市污水处理厂污泥处理利用的主要障碍是污泥中过多的水分和重金属,增加运输、处理成本,造成二次污染问题.文章首先回顾了城市污泥的主要处理处置方法及其特点;接着介绍了污泥农用的作用和限制;主要阐述了用污泥干化床同时种植重金属超富集植物、低累积作物或钾高累积植物,通过植物提取降低城市污泥重金属含量,同时生产植物产品,并使污泥干化和稳定化的城市污泥特种植物处理系统;最后,针对一种处理方法难以消化一个大城市全部污泥的现状,提出城市污泥中转处理场的设想,把植物处理系统、堆肥、太阳能干燥、有机肥和复合肥生产、建材制造等多项技术集成,建立城市污泥专用处理和集散基地,解决日益增多的城市污泥的处置问题.其成本应低于目前采用的填埋、焚烧、制砖等处理方法,具有显著的社会、经济和环境效益.  相似文献   

6.
化学解偶联剂和OSA联合工艺对剩余污泥的减量化作用   总被引:2,自引:0,他引:2  
比较研究了添加化学解偶联剂3,3′,4′,5-四氯水杨酰苯胺(TCS)的活性污泥工艺、好氧-沉淀-缺氧(OSA)工艺、添加TCS的OSA联合工艺所引起的解偶联代谢对剩余污泥的减量化效果。结果表明,3种工艺的剩余污泥量分别比对照工艺下降33.99%、25.94%和46.90%。和对照相比,COD去除率没有明显影响,总氮去除率下降。TCS影响了污泥的沉降性能,但OSA可使污泥的SVI值下降。污泥中的微生物种群结构在180 d运行后发生了变化。以上结果表明,添加TCS的OSA联合工艺将是一条适宜的污泥减量化技术途径。  相似文献   

7.
城市污水处理厂污泥处理处置的政策分析   总被引:8,自引:0,他引:8  
岑超平  张德见  韩琪 《生态环境》2005,14(5):803-806
简要介绍了城市污水处理厂污泥处理处置技术,提出污泥产业发展政策的建议,指出土地利用是符合我国国情的污泥处置的方向之一:污泥处理技术主要有减量化、浓缩、脱水、消化、堆肥等;污泥处置技术主要有焚烧、填埋、土地利用、建材利用等。污泥处理处置应按照减量化、稳定化、无害化原则,鼓励污泥资源化综合利用。合理确定污水处理厂污泥处理处置设施的布局和设计规模;鼓励对污泥处理处置给与税、费优惠政策,明确将污泥处理处置的运营费用列入污水排污收费范围,建立科学的价格补偿机制;政府在污泥产业发展中起着较为重要的作用,主要体现为服务与监督,包括承诺、保障和协调三个方面。  相似文献   

8.
污泥堆肥过程中主要性质及氮素转变   总被引:7,自引:0,他引:7  
徐灵  王成端  姚岚 《生态环境》2008,17(2):602-605
目前堆肥过程中氮素损失比较严重,通常达到50%左右.针对这一问题,文章以污泥和秸秆为原料,进行了不同配比条件下高温好氧堆肥试验,研究了堆肥过程中各主要性质及各种形态氮素的转化规律.结果表明,堆肥有效实现了污泥无害化、减量化和资源化.在pH值和温度较高条件下的氨气大量挥发是堆肥过程氮素损失的重要途径,且不同的物料配比会对氮素损失造成影响,C/N比低的配比氮素损失较大.适当降低堆料温度、添加酸性物质以降低pH值等措施均可减少氮素损失.  相似文献   

9.
以北京市为例,估算不同电价及运输距离下填埋、焚烧及堆肥等方式的城市污泥处理处置成本,在此基础上讨论各种处理处置方案的前景,展望北京市污泥处理处置出路。污泥填埋在一定时期内还将是主要处理处置方式,但所占比例将逐渐下降;堆肥是经济上较为可行的处理处置方式,适合大力推广;随着经济实力与技术水平提高,焚烧法可以适用于个别特殊地点。同时,分析了政府补贴对污泥处理处置效益的影响。  相似文献   

10.
部分城市污泥中氯苯类化合物的初步研究   总被引:12,自引:0,他引:12  
应用GC/MS对我国 1 1个城市污泥中的 5种氯苯化合物 (CBs)进行了研究 .结果表明 ,各城市污泥中CBs的总含量 (ΣCBs)在 0 0 1 0— 6 91 7mg·kg- 1之间 ,绝大部分低于 1 0mg·kg- 1,依次是兰州 >北京 >香港大埔 >无锡 >香港元朗 >广州 >佛山>香港沙田 >西安 >珠海 >深圳 .各城市污泥的CBs都是以个别或少数化合物为主 ,显示出不同的分布特征 ,主要是 1 2 4 三氯苯和六氯苯 ,其它化合物含量普遍较低 .各种CBs化合物的最高含量主要分布于兰州污泥和无锡污泥中 .城市污泥中CBs的含量与污水来源、污水处理方式、污泥类型和CBs化合物的理化性质有关 .  相似文献   

11.
In China, over 1.43×107 tons of dewatered sewage sludge, with 80% water content, were generated from wastewater treatment plants in 2007. About 60% of the COD removed during the wastewater treatment process becomes concentrated as sludge. Traditional disposal methods used by municipal solid waste treatment facilities, such as landfills, composting, or incineration, are unsuitable for sludge disposal because of its high water content. Disposal of sludge has therefore become a major focus of current environmental protection policies. The present status of sludge treatment and disposal methodology is introduced in this paper. Decreasing the energy consumption of sludge dewatering from 80% to 50% has been a key issue for safe and economic sludge disposal. In an analysis of sludge water distribution, thermal drying and hydrothermal conditioning processes are compared. Although thermal drying could result in an almost dry sludge, the energy consumption needed for this process is extremely high. In comparison, hydrothermal technology could achieve dewatered sewage sludge with a 50%–60% water content, which is suitable for composting, incineration, or landfill. The energy consumption of hydrothermal technology is lower than that required for thermal drying.  相似文献   

12.

The huge amounts of sewage sludge produced by municipal wastewater treatment plants induce major environmental and economical issues, calling for advanced disposal methods. Traditional methods for sewage sludge disposal increase greenhouse gas emissions and pollution. Moreover, biochar created from sewage sludge often cannot be used directly in soil applications due to elevated levels of heavy metals and other toxic compounds, which alter soil biota and earthworms. This has limited the application of sewage sludge-derived biochar as a fertilizer. Here, we review biomass and sewage sludge co-pyrolysis with a focus on the stabilization of heavy metals and toxicity reduction of the sludge-derived biochar. We observed that co-pyrolyzing sewage sludge with biomass materials reduced heavy metal concentrations and decreased the environmental risk of sludge-derived biochar by up to 93%. Biochar produced from sewage sludge and biomass co-pyrolysis could enhance the reproduction stimulation of soil biota by 20‒98%. Heavy metals immobilization and transformation are controlled by the co-feed material mixing ratio, pyrolysis temperature, and pyrolysis atmosphere.

  相似文献   

13.

Goal and Scope

At all times animal as well as human excrements have been used as organic fertilizers. Disposing of municipal sewage sludge on arable farmland means saving mineral fertilizer to conserve the exhaustible resource phosphorus; one can consider this kind of recycling management as a contribution to a sustainable regional development. However, the use of sludge implies a significant release of pollutants. Hence, in Germany as well as internationally, this is a controversial issue and therefore it needs to be re-evaluated under consideration of regional circumstances.

Methods

A material flow management framework is used to first analyse toxic, fertilizing and legal aspects of the ‘sludge metabolism’ in Schleswig-Holstein, including involved participants. Then, the treatment of waste water as well as potential and actual recycling of domestic sewage sludge are regionally compared. The study is based on a survey of the municipal waste water treatment plants which serve more than 10.000 people including population equivalence; these plants cover about 94% of the sewage sludge in Schleswig-Holstein.

Results and Conclusions

After taking the phosphorus of manure into account, the modelled potentials of recycling on the scale of districts do not correspond with the actual use of sludge in agriculture. The disposal firms recycle the sludge where they can get the highest profit. By minimizing transaction costs, lager recycling distances can be compensated. The potential of phosphorus recycling is limited. The calculated state-wide amount is not more than 10% of the total phosphorus demand of the arable land, so the benefit is less important for the national economy. On the other hand, there is a significant discharge of pollutants mainly into the soil, where apart from copper and cadmium, the charge through sewage sludge is higher than through mineral fertilizer and manure. In addition, the risk of pollutants with endocrine disrupters is difficult to estimate.

Outlook

In respect of the net ecological effects, thermal utilization of sewage sludge, e.g. in clinker works, coal-fired power stations or waste incineration plants, combined with previous or additional phosphorus recovery from cinder, meets the criteria of sustainable material flows more than its use on arable land. Even though these disposal options are still more expensive, law induced adjustment of the waste market and more strict land application regulations will reduce their price differences. This will make a middle-term change from the agricultural use to a thermal recycling of sewage sludge possible to avoid soil impacts and fulfil the requirements of a sustainable development.  相似文献   

14.
Background, aim and scope The application of nanosilver is increasing. Knowledge on the fate and behavior of nanosilver in wastewater and wastewater treatment plants is scarce. Studies under real world conditions are completely lacking. We studied (1) the impact of nanosilver on the nitrification of sewage sludge, (2) quantified the mass flow of nanosilver in a pilot-plant, and (3) verified the mass balance in a full-scale municipal wastewater treatment plant where nanosilver is introduced to the municipal plant by an indirect discharger. Materials and Methods The addition of four different nanosilver additives on ammonia oxidation in activated sludge has been studied in batch-reactors at two concentrations (1, 100?mg/L Ag) with two exposure times (2?h, 6?days). The pilot-plant treating 70 population equivalents of domestic wastewater is operated with a 12?day sludge age. Nanosilver was applied to the activated sludge tank within two sludge ages. The silver concentrations were measured in sludge and effluent samples during dosing and the following two sludge ages. The adsorption and speciation of silver particles has been analyzed using scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX). Influent, effluent and sludge were sampled on a full-scale plant (60?000 equivalent inhabitants) and analyzed for silver. Results Silver nitrate, metallic nanosilver, nano-scaled silver chloride and microcomposite silver did not show any effect on ammonia oxidation after the addition of 1?mg/L Ag to the activated sludge (corresponding to 250?mg Ag per kg solids). In contrast, 100?mg/L Ag inhibited the nitrification process by 100?% after the addition of silver nitrate and 20–30?% after addition of colloidal polymer-coated nanosilver. A complete mass balance of the pilot-plant, a steady-state system with known fluxes, demonstrates significant enrichment of silver in the sewage sludge (96?%) after the addition of silver chloride to the plant and small losses of silver into the secondary effluent (4?%). The mass fluxes are similar to metallic colloidal nanosilver investigated under the same conditions. The mass balance has been consistently confirmed by the full-scale study in a municipal wastewater treatment plant. The silver fluxes correspond to the fluxes of the suspended solids in sludge and effluent. Overall, it is estimated that from public wastewater treatment plants about 4–40?mg/a Ag per inhabitant equivalent are discharged annually to the receiving water. The analysis by SEM-EDX demonstrates adsorption and incorporation of nanosilver on biological flocs. This method yields first insight into complex building and transformation of silver associated with sulfide after adding metallic nanosilver and silver chloride to wastewater. Discussion Silver ions released from nanosilver react immediately with large amounts of chloride present in wastewater to form silver chloride. Silver ions may react with organic ligands or sulfide groups additionally. Consequently, even silver nitrate added with 1?mg/L Ag (250?mg Ag/kg TS) to activated sludge did not inhibit nitrification activity. Very high amounts of nanosilver, i.?e. 100?mg/L Ag, overburdened the system and equilibrium condition between silver ion release and ligands was not reached. The mass balance reflects the excellent attachment of nanosilver to activated sludge and biological flocs. Therefore, the main elimination process of nanosilver is attachment to the activated sludge. The elimination of nanosilver is high compared to organic and inorganic micro pollutants omnipresent in wastewater. Any further reduction of suspended solids in the effluent water will reduce the silver load. Conclusions Generally, in wastewater nanosilver occurs bonded to activated sludge flocs and therefore the elimination of nanosilver is efficient under operation conditions typical for wastewater treatment plants. The major fraction of nanosilver is removed from the system by the excess sludge withdrawal. Nonetheless, the efficiency may be further improved by a tertiary filtration step. All analyses of influent, effluent and sludge confirmed that silver exists as silver sulfide. Due to a negligible water solubility of this silver species, silver ions are not subsequently released. Recommendations and perspectives Nanosilver research should be driven to the identification of transformation processes in real environmental matrices and the influence of coatings on the adsorption behavior. There is no need for action to take special measures for nanosilver removal in the area of municipal wastewater treatment plants compared to ubiquitous hazardous organic pollutants may present in wastewater. Nevertheless, source control measures following the precautionary principle should be performed.  相似文献   

15.
长江三角洲地区城市污泥的综合生物毒性研究   总被引:9,自引:2,他引:9  
运用发光细菌法对我国长江三角洲地区16个城市中54个污泥样品的综合急性生物毒性进行了测定,并以毒性较为稳定的HgCl2作为参比毒物,以发光细菌抑光率、相当标准毒物HgCl2质量浓度及百分数等级比较法毒性划分标准评价城市污泥的毒性。结果表明,供试的不需稀释测定毒性的城市污泥中,有13个是剧毒的,占样品总数30.95%;需稀释测定毒性的城市污泥中,毒性等级为Ⅰ级的8个,占样品总数66.67%。长江三角洲地区城市污泥大部分有较高的综合急性生物毒性,这与含多种高量的有毒重金属有关。城市污泥对发光细菌毒性的大小与城市污泥来源、污水处理工艺及污泥类型等因素有关。上海地区的污泥毒性大于江苏和浙江地区;42个毒性较小的污泥中,大部分氧化沟处理的城市污泥的毒性要大于A^2/O(厌氧-缺氧/好氧)处理的,12个毒性较大的污泥中处理工艺多为活性污泥处理与A^2/O处理;大部分以生活污水和混流污水为主的城市污泥毒性要高于以工业污水为主的城市污泥。  相似文献   

16.
城市污泥中铜锌的化学形态及其去除   总被引:1,自引:0,他引:1  
利用连续提取法研究了城市污泥中铜和锌的化学形态,结果表明:污泥中铜和锌都以稳定性较好的硫化物及有机结合物、残渣态形式存在,生物毒性较小,通过适当处理后可以安全加以利用;在此基础上,研究了利用乙酸和双氧水去除污泥中铜和锌的适宜工艺条件,结果表明:在室温条件下,在pH值为4的环境中,利用添加H_2O_2的浓度为2mol/L的乙酸溶液,反应时间为4h,就可以将污泥中超过95%以上的铜和锌淋滤去除。  相似文献   

17.
This paper analyzes dewatered sludge drying using the multifractal theory. The drying rates of cylindrical sludge with equal masses but different cross-sectional diameters was studied, from which multifractal parameters such as partition function and quality exponent were obtained. The parameters acquired were used to calculate the multifractal singularity spectrum and indicate the presence of multifractal characteristics. The smaller cross-sectional diameters of the sludge were found to be non-homogeneous, and required quantitative methods to analyze.  相似文献   

18.
In Nuremberg (Germany), each year about 25,000 tons (dry matter) of sewage sludge are obtained as by-product of waste water treatment. The digested sludge consists of 96% water. Until 1992 it was thermally stabilized using the Porteous procedure: the sludge was heated in an autoclave up to a temperature of 180–200 °C at a pressure of 28 bar. After pressure reduction and moving to a thickener, a substantial part of the liquid could be removed. After running through a chamber filter, the sludge contained only about 50% dry matter. This treatment does not only remove water; organic matter is also degraded or evaporated. Between November 1991 and May 1992, the sludge was analyzed four times before and after the drying process and examined for heavy metals (Pb, Cd, Cr, Cu, Ni, Hg, Zn), polychlorinated biphenyls (PCB) and PCDD/F. The concentration of heavy metals and PCB (related to dry matter) increased by a faktor of 1.3 after the drying process. This effect may be explained by the decrease of organic matter during drying. In the case of PCDD/F, the ITQ increased by a factor of 3.2, for some congeners even by a factor of 8. The only explanation can be that during thermal conditioning PCDD/F is formed by precursors as chlorophenols. This formation is probably catalyzed by metals as copper or nickel and sped up by the higher temperatures.  相似文献   

19.
● The performance and costs of 20 municipal WWTPs were analyzed. ● Effluent COD and NH4+-N effluent exceed the limits more frequently in winter. ● Nitrification and refractory pollutant removal are limited at low temperatures. ● To meet the national standards, electricity cost must increase by > 42% in winter. ● Anammox, granular sludge, and aerobic denitrification are promising technologies. Climate affects the natural landscape, the economic productivity of societies, and the lifestyles of its inhabitants. It also influences municipal wastewater treatment. Biological processes are widely employed in municipal wastewater treatment plants (WWTPs), and the prolonged cold conditions brought by the winter months each year pose obstacles to meeting the national standards in relatively cold regions. Therefore, both a systematic analysis of existing technical bottlenecks as well as promising novel technologies are urgently needed for these cold regions. Taking North-east China as a case, this review studied and analyzed the main challenges affecting 20 municipal WWTPs. Moreover, we outlined the currently employed strategies and research issues pertaining to low temperature conditions. Low temperatures have been found to reduce the metabolism of microbes by 58% or more, thereby leading to chemical oxygen demand (COD) and NH4+-N levels that have frequently exceeded the national standard during the winter months. Furthermore, the extracellular matrix tends to lead to activated sludge bulking issues. Widely employed strategies to combat these issues include increasing the aeration intensity, reflux volume, and flocculant addition; however, these strategies increase electricity consumption by > 42% in the winter months. Internationally, the processes of anaerobic ammonium oxidation (anammox), granular sludge, and aerobic denitrification have become the focus of research for overcoming low temperature. These have inspired us to review and propose directions for the further development of novel technologies suitable for cold regions, thereby overcoming the issues inherent in traditional processes that have failed to meet the presently reformed WWTP requirements.  相似文献   

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