Classification and quantification of excavated soil and construction sludge: A case study in Wenzhou,China

With rapid urbanization in China, a large amount of excavated soil and construction sludge is being generated from geotechnical and underground engineering. For sustainable management of these construction wastes, it is essential to quantify their production first. The present study has attempted to classify the excavated soil and construction sludge according to their composition and geotechnical properties (particle size, water content, plasticity index). Based on these classifications, a new approach was proposed to quantify the production. The said approach was based on multi-source information, such as the urban topographic map, geological survey reports, urban master plan, and remote sensing images. A case study in Wenzhou city of China was also pursued to illustrate the validity of the newly developed approach. The research showed that in 2021–2025, the total excavated soils and construction sludge production in Wenzhou would reach 107.5 × 10⁶ and 81.7 × 10⁶ m³, respectively. Furthermore, the excavated soil was classified into the miscellaneous fill, crust clay, muddy clay and mud with silty sand. Likewise, the construction sludge was classified as liquid sludge and paste-like sludge. The classification and quantification can serve as guidance for disposal and recycling, thereby leading to high-level management of waste disposal.     

我国污泥处理、处置技术政策探讨

为了对我国污泥处理、处置提出合理规划，控制污泥污染，对污泥产量的估算进行了初步探讨，从多个角度阐述了在污泥问题日益严重的情况下制定污泥处理、处置技术政策的必要性，并提出了相关建议。     

上海部分企业工业废水污泥的处理、处置现状

在实地调查上海部分企业工业废水污泥产生量、污泥性质、处理及处置现状的基础上，分析了目前上海工业废水污泥处理、处置所存在的问题，提出我国必须尽快制定一套完善的技术标准和措施法规，使污泥的产生、处理、处置和环境保护之间达到一个良好的平衡。     

Physical characterisation of the sludge produced in a sequencing batch biofilter granular reactor

Sequencing batch biofilter granular reactor (SBBGR) is a recently developed biological wastewater treatment technology characterised by a very low sludge production, among other numerous advantages. Even if costs for sludge treatment and disposal are mainly dependent on the amount of sludge produced, sludge properties, especially those linked to solid-liquid separation, play a key role as well. In fact, such properties deeply influence the type of treatments sludge has to undergo before disposal and the final achievable solids concentration, strongly affecting treatment and disposal costs. As sludge from SBBGR is a special mixture of biofilm and aerobic granules, no information is available so far on its treatability. This study addresses the characterisation of the sludge produced from SBBGR in terms of some physical properties (settling properties, dewaterability, rheology). The results show that such sludge is characterised by good settling and dewatering properties, adding a new advantage for the full-scale application of SBBGR technology.     

浙江省城市污水处理厂产泥现状与处置对策

目前浙江省污水处理厂的污泥产量为100×104t/a,污泥处置问题日益突出。笔者通过调查和统计,分析了浙江省污水处理厂污泥的产生情况、特点和处置状况,并对未来的污泥处置提出了对策和建议。     

Sewage Sludge Production, Treatment and Disposal in the European Union

Sludge production and disposal are entering a period of dramatic change, driven mainly by EC legislation. The urban waste water treatment Directive will result in at least 50% more sludge being produced by the end of 2005 and, during the next decade, sludge disposal to all the established outlets could become increasingly difficult or, in the case of sea disposal, will become illegal. The challenge facing the members of the European Union is how to (a) maintain cost-effective and secure methods of sludge disposal and (b) engender public confidence in all disposal and recycling options. What is required is not so much innovative technology, although this may be essential, but more innovative attitudes and approaches to promotion and defending existing outlets.
This paper describes the likely pattern of sludge production, treatment and disposal which will emerge during the implementation of recent EC directives and other national policies in Europe, and focuses on the areas and issues which require innovative approaches.     

固定化生物催化剂用于污水厂污泥减量的研究

目前,剩余污泥的处理与处置已成为困扰污水厂的难题之一.采用固定化生物催化剂(IBC)在某城市污水处理厂进行污泥减量试验,结果表明:投加IBC的CASS池污泥减量效果明显,投药1个月后,外排剩余污泥量及产泥量均大幅减少,第3,4个月没有外排剩余污泥,且MLSS维持在1500 mg/L左右,有效地从源头实现了污泥减量.同时,投加IBC对出水水质无负面影响,且能够提高水质净化效果,投药池对COD、NH3-N、TP的平均去除率分别为84.18%、94.39%、63.17%,较对照池的79.88%、92.80%、49.61%均有所提高,出水水质优于对照池.     

Cairo Sludge Disposal Study

This paper describes the establishment of the Cairo sludge disposal study which is being funded within the Mediterranean Environmental Technical Assistance Programme through the European Investment Bank and promoted by the Cairo Wastewater Organization. The study is a demonstration programme to show how the problems of sludge disposal from large, rapidly developing cities, such as Cairo, can be solved through the establishment of a practical system for the safe re-use of sewage sludge in agriculture. It is being carried out principally through a series of demonstration field trials and the development of ettensive information. This study is of relevance to Egypt and other countries with similar agricultural and environmental conditions, where (a) sludge production is increasing, (b) water protection is essential, and (c) appropriate environmentally acceptable solutions are urgently required.     

城市污泥无害化建材技术发展研究

污泥污水厂建设规模的不断扩大导致城市污泥生成量持续增高。污泥处置的方法有污泥无害化和资源化处理,污泥作为建材利用是污泥处置方式的一个方向,将污泥作为建材的原材料可以更好的缓解污泥危害生态环境,也更好的体现了污泥的资源化和减量化。本文简要介绍污泥作为建材利用的几种主要形式,包括污泥制砖、污泥制陶粒、污泥制水泥和其他方面,以期为污泥建材利用的实际运用提供一定的参考依据。     

The Impact of EU and UK Environmental Pressures on the Future of Sludge Treatment and Disposal

Current and future production of sludge in the UK is estimated, and it is predicted that recycling to agricultural land and incineration (with energy recovery) will be the major disposal options for sludge in the future. Environmental pressures on sludge recycling to land may lead to restrictions on applications in terms of nitrogen content and more stringent limits for metals in soils. Attention to sludge quality and the development of quality management practices in utilization or disposal operations will help to minimize environmental concerns and facilitate sludge disposal to all outlets. Focal points for quality assurance in sludge recycling operations are listed, and environmental pressures on sludge use in agriculture are discussed in detail. Use in agriculture involves recycling a secondary resource, and calling the resource 'biosolids' is part of promoting this excellent example of good environmental management.     

Progress and perspectives of sludge ozonation as a powerful pretreatment method for minimization of excess sludge production

The treatment and disposal of excess sludge represents a bottleneck in wastewater treatment plants (WWTP) worldwide, due to environmental, economic, social and legal factors. The ideal solution to the problem of sludge disposal is to combine sludge reduction with the removal of pollution at the source. This paper presents an overview of the potential of ozonation in sludge reduction. The full-scale application of ozonation in excess sludge reduction is presented. Improvements in the biodegradability of the ozonated sludge were confirmed. The introduction of ozonation into activated sludge did not significantly influence effluent quality but improved the settling properties of the sludge. An operation with a suitable sludge wasting ratio seems to be necessary to prevent accumulation of inorganic and inert particles for long-term operation. Sludge ozonation to reduce excess sludge production may be economical in WWTP which have high sludge disposal costs and operational problems such as sludge foaming and bulking. The recommended ozone dose ranges from 0.03 to 0.05 g O₃/g TSS, which is appropriate to achieve a balance between sludge reduction efficiency and cost. An effort to design and optimize an economic sludge reduction process is necessary.     

城市污水处理厂污泥处理处置规划编制的探讨

针对城市污水厂污泥处理处置带来的一系列问题,近年来不少城市开始对城市污水规划进行补充或编制污泥处理处置相关规划。本文就编制城市污泥规划中的污泥量预测问题、污泥工艺路线问题、污泥处理处置设施布局、厂址等问题进行了探讨,以期对编制城市污泥处理处置规划提供一定的参考。     

剩余活性污泥处理的清洁生产方向

概述了活性污泥法污水处理过程中剩余污泥处理及处置的清洁生产方式,指出对于剩余污泥的处理而言减量化、资源化、无害化的顺序是其清洁生产应该遵循的主要顺序,并针对这三方面目前国内外的发展现状进行了论述.     

上海市污泥处理处置专项规划简介

城市污泥处理处置技术随着城市化进程的加快越来越受到重视.结合上海制定城市污泥处理处置专项规划的经验,认为在进行技术方案研究的同时,应充分了解整个服务范围内的污泥数量、污泥性质,并对污泥处置的潜在出路进行研究,继而确定处理处置场所的规划,提出实施处理处置的准入条件和法规政策.     

Mesophilic and thermophilic anaerobic digestion of primary and secondary sludge. Effect of pre-treatment at elevated temperature

Anaerobic digestion is an appropriate technique for the treatment of sludge before final disposal and it is employed worldwide as the oldest and most important process for sludge stabilization. In general, mesophilic anaerobic digestion of sewage sludge is more widely used compared to thermophilic digestion. Furthermore, thermal pre-treatment is suitable for the improvement of stabilization, enhancement of dewatering of the sludge, reduction of the numbers of pathogens and could be realized at relatively low cost especially at low temperatures. The present study investigates (a) the differences between mesophilic and thermophilic anaerobic digestion of sludge and (b) the effect of the pre-treatment at 70 degrees C on mesophilic and thermophilic anaerobic digestion of primary and secondary sludge. The pre-treatment step showed very positive effect on the methane potential and production rate upon subsequent thermophilic digestion of primary sludge. The methane production rate was mostly influenced by the pre-treatment of secondary sludge followed by mesophilic and thermophilic digestion whereas the methane potential only was positively influenced when mesophilic digestion followed. Our results suggest that the selection of the pre-treatment duration as well as the temperature of the subsequent anaerobic step for sludge stabilization should depend on the ratio of primary to secondary sludge.     

考虑淤泥处置场荷载特点的软土地基处理方法

淤泥处置场占地面积较大,对深厚的软土地基,若采用常规的复合地基处理方式无疑将大规模增加工程投资。本文考虑淤泥处置场的荷栽特点,将淤泥的处置过程当作分级加载的过程,分析地基在处置场运行期间地基承载力的提高,通过控制作业程序,使淤泥堆填的速度和荷载与地基承载力随时间的增长相适应,同时设置加筋砂石垫层,为软土地基提供排水层,减小库区的不均匀沉降,提高地基承载力,。最后结合某淤泥处置场工程,分析了该地基处理思路的可行性,对淤泥处置场的方案提出了优化建议。本文的计算方法和地基处理方式可为软土地区污泥处置和垃圾填埋等工程提供有益的参考,     

污泥脱水、输送及储存系统的设计探讨与总结

污泥脱水、输送及储存系统是污泥处理处置工程的重要组成部分,以南宁某项目为例,介绍了污泥脱水工艺、进泥设备、加药系统及泥水分离阀的设计及优化建议;介绍了污泥输送螺旋、缓存料斗及料位检测的工程应用特点,提出一体化破拱装置,详述污泥输送泵及其故障处理方式;介绍了污泥储存系统的管道、入料口的设计要点,滑架破拱装置的设计优化及其液压系统热平衡分析等。该项目投入运营后,脱水污泥含水率降至80%,污泥的日输送量达到66.85 m³/d,污泥储存系统储存量达到200 m³,实现了污泥的减量化生产。最后对该工程进行技术经济分析,为同类项目提供参考。     

A review of secondary sludge reduction technologies for the pulp and paper industry

The broader application of the activated sludge process in pulp and paper mills, together with increased production, have amplified sludge management problems. With sludge management costs as high as 60% of the total wastewater treatment plant operating costs, and increasingly stringent environmental regulations, it is economically advantageous for pulp and paper mills to reduce their biosolids production. In order to provide a state-of-the-art review of secondary sludge reduction technologies, we have considered the scenarios of lower sludge production through process modifications, and waste-activated sludge reduction through post-treatment. A critical evaluation of all candidate reduction technologies indicates that sludge reduction through treatment process changes appears more appealing than post-treatment alternatives. The former approach offers a clear advantage over the latter in that the treatment process changes reduce sludge production in the first place, thus decreasing sludge management cost. Although it is technically feasible to eliminate the need for sludge disposal, it is unlikely to be economically feasible at this time.     

The Development of a Sludge Disposal Strategy for the Hong Kong Territories

Sludge arisings in the Hong Kong Territories are predicted to increase from the current level of 44 300 tDS/annum to 314000 tDS/annum. This has led to a need to examine the treatment and disposal facilities required for the future. Disposal facilities were found to be restricted, with virtually no suitable land for a liquid disposal route and a sea route limited to the present quantities. Only landfill remained as the major disposal outlet, but this is also limited by the moisture absorbence capacity of the emplaced material and limiting metal concentrations.
In order to match the sludge production to the disposal outlet capacity, a series of process options was considered. Transportation studies using pumping, road and sea networks were undertaken and the environmental impact assessment of introducing thermal technologies was reviewed. Finally the various options were evaluated using a modified version of the Water Research Centre's WISDOM model.     

镇江市新区第二污水处理厂污泥处置方式选择

污泥处置的目的是以减量化、资源化、无害化为原则的。目前在世界各国,填埋、农用、干化和焚烧是污泥处置的几种主要方法。近年来,污泥焚烧技术成为处理污泥的主流。通过对镇江市新区第二污水处理厂的污泥进行鉴定分析,并对污泥焚烧方式和污泥焚烧的基本条件加以分析,可知该厂污泥不属于危险固废,混合焚烧是该厂污泥合理的处置途径。