生物反应器填埋场系统渗滤液的脱氮性能探析

目前,较为常用的生活垃圾处理方法有填埋法、焚烧法以及堆肥法,其中填埋处理技术以其自身诸多的优点,被广泛应用于垃圾处理当中。但是由于我国对于该项技术的研究起步较晚,从而使得实际应用中存在一些问题。虽然COD、BOD等问题已经得到有效解决,但氨氮处理效果仍旧欠佳。借此,本文就生物反应器填埋场系统渗滤液的脱氮性能进行探析。     

城市生活垃圾的危害与处理方法浅析

随着城市生活垃圾产生量不断增长,其对环境的危害逐步扩大。城市生活垃圾在收集、运输、处置过程中垃圾所含有的和产生的有害成分会对大气、土壤、水体造成污染。解决垃圾问题的目标是使垃圾减容、减量、资源化、能源化和无害化。目前在我国乃至世界范围内广泛使用的城市生活垃圾处理方式主要有卫生填埋、焚烧和堆肥三种。     

厨余垃圾厌氧消化合成高附加值化学品的研究进展

厨余垃圾在生活垃圾中占比巨大,已对食品安全、自然资源可持续利用和环境造成了不利影响,故亟须实现厨余垃圾的有效处理及利用。目前处理厨余垃圾最常用的方式主要包括填埋与焚烧,但存在易产生二次污染、耗能大等问题,阻碍了其大规模应用。厨余垃圾具有有机质含量高的特性,通过生物炼制合成高附加值化学品(如有机酸等),不仅可实现产品的清洁生产,也可提高厨余垃圾的经济价值。本文首先概括了国内外厨余垃圾的处理现状及处理方法,其中厌氧消化法可清洁生产高附加值产品,展示出巨大的研究潜力。因此,对厌氧消化厨余垃圾合成化学品进展进行详细综述,最后对构建人工混菌培养体系和生物膜调控在厨余垃圾生物制造领域的应用提出了展望。     

基于混合生命周期评价的生活垃圾处理系统生态效率分析

基于混合生命周期评价(Hybrid life cycle assessment,HLCA)提出一种改进生态效率模型,系统评价卫生填埋、卫生填埋⁃填埋气利用、焚烧发电、堆肥+卫生填埋和堆肥+焚烧发电5种我国典型生活垃圾处理情景的生态效率,并探究可持续性包含的环境、经济和社会多维权衡关系。结果表明,具有最大生态效率的生活垃圾处理情景因可持续性维度选取不同而异,如考虑人体健康损害影响,焚烧发电情景具有最大经济生态效率,而卫生填埋⁃填埋气利用情景具有最大社会生态效率。生活垃圾处理系统的可持续性评价维度之间具有显著的权衡关系,忽略某些影响类型可能带来问题转移。5种生活垃圾处理情景的环境影响各异,非焚烧情景气候变化影响和焚烧情景人体毒性影响突出。机器设备和燃料使用对资源消耗影响贡献最大,而生活垃圾处理过程对经济效益和其他环境影响贡献最大。本文提出的改进生态效率模型可以定量评价生活垃圾管理系统生态效率及权衡关系,为有效制定生活垃圾管理政策提供全面的信息支持。     

生物干燥处理城市垃圾技术的研究进展

生物干燥是对城市垃圾的一种预处理技术。它是利用生物反应放热来干燥城市垃圾,以改善其燃烧特性。经常用于在机械生物处理工厂干燥城市垃圾。生物干燥技术与堆肥工艺不同,它旨在干燥和保留垃圾基质中的生物质含量。在生物干燥反应器中主要干燥机制为空气对流蒸发,而物料的物理特性对干燥效果也有一定影响。反应器通风系统的类型的选择也是生物干燥的一个重要的影响因素。本文主要介绍了影响生物干燥过程的各项因素和研究进展。     

填埋覆土甲烷氧化微生物及甲烷氧化作用机理研究进展

甲烷是一种长期存在于大气中的温室气体,它对温室效应的贡献率是二氧化碳的26倍.生活垃圾填埋场是大气甲烷的主要产生源之一,由其产生的甲烷约占全球甲烷排放总量的1.5%～15%.甲烷氧化微生物在调节全球甲烷平衡中起着重要作用.垃圾填埋场覆土具有相当强的甲烷氧化能力.填埋覆土甲烷氧化菌及其氧化作用机理的研究,已成为环境微生物学研究领域的热点之一.本文对生活垃圾填埋场填埋覆土中甲烷氧化微生物、甲烷氧化机理及动力学机制、甲烷与微量填埋气体的共氧化机制以及影响甲烷氧化的环境因子研究的最新进展进行综述,并对生活垃圾填埋场甲烷氧化微生物的研究进行展望.     

垃圾填埋场氧化亚氮排放控制研究进展

填埋是国内外城市生活垃圾处理的一种主要方式.垃圾填埋场是温室气体氧化亚氮(N2O)和甲烷(CH4)的重要排放源.作为一种高效痕量的温室气体,N2O具有极高的潜在增温效应,其每分子潜在的增温作用是二氧化碳(CO2)的296倍.而且N2O能在大气中长期稳定存在,对臭氧层具有较强的破坏作用.本文针对垃圾填埋场N2O排放的控制研究,概述了垃圾填埋处理过程中主要排放源的N2O排放及其影响因素,提出了现阶段适应我国垃圾填埋场N2O排放控制的一系列措施,并展望了垃圾填埋场温室气体N2O排放控制理论和技术的研究方向.     

填埋场甲烷生物氧化过程及甲烷氧化菌的研究进展

生活垃圾填埋场甲烷排放量约占全球甲烷排放总量的6%~12%,是大气甲烷的重要生物源之一。生活垃圾填埋场覆土中的甲烷氧化菌能氧化填埋气中的甲烷,是填埋场甲烷排放控制的重要途径。本文综述了填埋场覆盖层甲烷生物氧化的微生物机理、覆土甲烷生物氧化强化工艺和技术、填埋场环境中甲烷氧化微生物研究的最新进展。现有研究有效提高了填埋场覆盖层甲烷生物氧化的性能,但对占填埋场甲烷产生总量很大比重的封场前甲烷排放控制关注较少,因此,今后应加强封场前甲烷排放的研究,提高日覆盖和中间覆盖材料的甲烷氧化率并加快其甲烷氧化启动。     

餐厨垃圾协同剩余污泥发酵产酸的生物过程与影响因素研究进展

资源化利用是应对餐厨垃圾(Kitchen waste,KW)和剩余污泥(Excess sludge,ES)快速增加的有效方法,而厌氧发酵获得挥发性脂肪酸(Volatile fatty acids,VFAs)是其中的重要方式之一,但单一底物限制了VFAs的高效生产。近年来,不同底物厌氧共发酵产生VFAs被广泛研究与应用,文中分析了KW和ES单独和协同发酵产酸过程的特点,总结了厌氧发酵产酸过程及其生物代谢机制,阐述了环境因子及微生物群落结构对厌氧发酵产物类型及系统产物回收效率的影响。并进一步提出了针对区域饮食习惯、接种外源微生物构建稳定高效的定向产酸发酵体系以及KW和ES与原位污水间的耦联作用的研究方向。以期减少垃圾回收站及污水处理厂的运行成本,为实现城市有机固体垃圾处理与污水处理共赢提供参考。     

新书介绍

内容简介:环境保护是我国的基本国策,而城市垃圾处理是城市环境保护的重要内容,也是衡量城市文明程度和城市管理水平的重要标志之一。近几年来,我国的大部分城市都正在积极的进行城市生活垃圾处理工程的探索和实践,但由于国内无系统的垃圾处理理论和少有成功的实例,而从国外引进的卫生填埋、堆肥、焚烧发电三大处理方式均不合中国国情。     

Segmentation scale parameter influence on the accuracy of detecting illegal landfills on satellite imagery. A case study for Novo Sarajevo

Illegal waste dumping has been widely regarded as one of the biggest source of environmental damage. Illegal landfills are a prevailing problem existing in a large number of countries. To control and better manage illegal landfills, it is necessary to know the current locations and contents of illegal landfills. This could increase efficiency in illegal landfill management and preserve the biodiversity and ecological balance. Remote sensing methods have been proven extremely effective in detecting potential illegal landfill sites. This paper investigates the relationship between the segmentation scale parameter and the detection accuracy of illegal landfill sites in urban areas that are not covered by vegetation or buried in the ground. The research showed that there is an optimal scale parameter (SP = 20) value for the used satellite image Pléiades 1B and area of interest (Novo Sarajevo municipality). The scale parameter's stated value gives maximum Kappa values and Overall accuracy coefficients for detected illegal landfills on the satellite image.     

Sanitary Waste Landfill Effects on an Invasive Wild Pig Population

Being opportunistic omnivores, wild pigs (Sus scrofa) readily feed on edible garbage. Given the presence of substantial volumes of edible food waste, large multi-county and regional municipal sanitary waste landfills constitute attractive forage resources for pigs, providing a year-round anthropogenic source of potentially high-quality forage. Our objective was to assess the effects that a large regional landfill has on the local pigs foraging in that facility's waste disposal cells. The landfill, located on the United States Department of Energy's Savannah River Site (SRS) in South Carolina, USA, became operational in 1998 and pigs began foraging there in 2001. By 2009 >100 pigs/night were observed foraging in the landfill, suggesting landfill establishment may have important consequences for population dynamics, public safety, and disease transmission. We evaluated changes in body mass, fetal litter size, numbers of pigs removed, and wild pig-vehicle collisions (WPVCs) before (1980–2000) and after (2001–2019) pigs began foraging in the landfill on SRS. Body mass during the after period increased to a greater extent for pigs in the vicinity of the landfill compared to pigs on the rest of SRS. Fetal litter size increased for pigs in the vicinity of the landfill, whereas it remained unchanged on the rest of SRS. Our density surrogate (number of pigs harvested) increased around the landfill during the after period by 2.9 times, whereas on the rest of the site it only increased by 53%. No WPVCs occurred adjacent to the landfill before 2001, but WPVCs increased along the 2 major roads bordering the landfill after 2001. Effects of sanitary waste landfills on wild pig populations scavenging there can present unique challenges to population management, control, public safety, and disease transmission. Potential approaches to address these challenges could be exclusion fencing to prevent access to the landfill's waste disposal cells or enhanced placement of waste cell covers to reduce access. © 2021 The Wildlife Society.     

Comparative life cycle assessments of incineration and non-incineration treatments for medical waste

Background, aim, and scope  Management of the medical waste produced in hospitals or health care facilities has raised concerns relating to public health, occupational safety, and the environment. Life cycle assessment (LCA) is a decision-supporting tool in waste management practice; but relatively little research has been done on the evaluation of medical waste treatment from a life cycle perspective. Our study compares the environmental performances of two dominant technologies, hazardous waste incineration (HWI) as a type of incineration technology and steam autoclave sterilization with sanitary landfill (AL) as a type of non-incineration technology, for specific medical waste of average composition. The results of this study could support the medical waste hierarchy. Materials and methods  This study implemented the ISO 14040 standard. Data on steam autoclave sterilization were obtained from an on-site operations report, while inventory models were used for HWI, sanitary landfill, and residues landfill. Background data were from the ecoinvent database. The comparative LCA was carried out for five alternatives: HWI with energy recovery efficiencies of 0%, 15%, and 30% and AL with energy recovery efficiencies of 0% and 10%. Results  The assumptions on the time frame for landfill markedly affect the impact category scores; however, the orders of preference for both time frames are almost the same. HWI with 30% energy recovery efficiency has the lowest environmental impacts for all impact categories, except freshwater ecotoxicity. Incineration and sanitary landfill processes dominate global warming, freshwater aquatic ecotoxicity, and eutrophication of incineration and non-incineration alternatives, respectively. Dioxin emissions contribute about 10% to human toxicity in HWI without energy recovery alternatives, and a perturbation analysis yielded identical results. As regards eutrophication, non-incineration treatments have an approximately sevenfold higher impact than incineration treatments. Discussion  The differences between short-term and long-term time frame assumptions mainly are decided by heavy metals dissolved in the future leachate. The high heat value of medical waste due to high contents of biomass, plastic, and rubber materials and a lower content of ash, results in a preference for incineration treatments. The large eutrophication difference between incineration and non-incineration treatments is caused by different N element transformations. Dioxin emission from HWI is not the most relevant to human toxicity; however, large uncertainties could exist. Conclusions  From a life cycle perspective, the conventional waste hierarchy, implying incineration with energy recovery is better than landfill, also applies to the case of medical waste. The sanitary landfill process is the key issue in non-incineration treatments, and HWI and the subsequent residues landfill processes are key issues in incineration treatments. Recommendations and perspectives  Integrating the medical waste hierarchy and constructing a medical waste framework require broader technologies to be investigated further, based on a life cycle approach. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Bioreactor landfill technology in municipal solid waste treatment: An overview

In recent years, due to an advance in knowledge of landfill behaviour and decomposition processes of municipal solid waste, there has been a strong thrust to upgrade existing landfill technologies for optimizing these degradation processes and thereafter harness a maximum of the useful bioavailable matter in the form of higher landfill gas generation rates. Operating landfills as bioreactors for enhancing the stabilization of wastes is one such technology option that has been recently investigated and has already been in use in many countries. A few full-scale implementations of this novel technology are gaining momentum in landfill research and development activities. The publication of bioreactor landfill research has resulted in a wide pool of knowledge and useful engineering data. This review covers leachate recirculation and stabilization, nitrogen transformation and corresponding extensive laboratory- and pilot-scale research, the bioreactor landfill concept, the benefits to be derived from this bioreactor landfill technology, and the design and operational issues and research trends that form the basis of applied landfill research.     

Conventional and exergetic life cycle assessment of organic rankine cycle implementation to municipal waste management: the case study of Mae Hong Son (Thailand)

Purpose

The critical issue of waste management in Thailand has been rapidly increasing in almost all of the cities due to the economic growth and rising population that could double the amount of solid waste in landfill area. The alternative ways of waste treatment that have more efficiency and effectiveness in terms of energy, ecology, and resources become the key issue for each municipality to replace the old fashioned technology and be able to enhance the ability of solid waste problem management. Waste to energy is one of the favorable approaches to diminish the amount of waste to landfill and utilize waste for electricity. The aim of this study is to identify and quantify the life cycle impacts of the municipal solid waste (MSW) of Mae Hong Son municipality (MHSM), and the case study is the selected waste treatment technology of the Refuse-Derived Fuel (RDF) hybrid with 20 kW of Organic Rankine Cycle (ORC).

Methods

The functional unit is defined as 1 t of MSW. The energy, environment, and resource impacts were evaluated by using Life Cycle Assessment (LCA); ReCipe and Net Energy Consumption were referred to calculate the environmental impacts and the benefits of energy recovery of WtE technology. Exergetic LCA was used to analyze the resource consumption, especially land use change.

Results and discussion

The results indicated that the environmental impacts were comparatively high at the operation stage of RDF combustion. On the other hand, the production stage of RDF illustrated the highest energy consumption. The ORC power generation mainly consumed resources from material and energy used. The ORC system demonstrated better results in terms of energy and resource consumption when applied to waste management, especially the land required for landfill. Substitution of electricity production from ORC system was the contributor to the reduction of both energy and resource consumption. Installation of spray dry and fabric filter unit to RDF burner can reduce heavy metals and some pollutants leading to the reduction of most of the impacts such as climate change, human toxicity, and fossil depletion which are much lower than the conventional landfill.

Conclusions

LCA results revealed that the environmental impacts and energy consumption can be reduced by applying the RDF and ORC systems. The exergetic LCA is one of the appropriate tools used to evaluate the resource consumption of MSW. It is obviously proven that landfill contributed to higher impacts than WtE for waste management.

     

The impact of landfilling and composting on greenhouse gas emissions – A review

Municipal solid waste is a significant contributor to greenhouse gas emissions through decomposition and life-cycle activities processes. The majority of these emissions are a result of landfilling, which remains the primary waste disposal strategy internationally. As a result, countries have been incorporating alternative forms of waste management strategies such as energy recovery from landfill gas capture, aerobic landfilling (aerox landfills), pre-composting of waste prior to landfilling, landfill capping and composting of the organic fraction of municipal solid waste. As the changing global climate has been one of the major environmental challenges facing the world today, there is an increasing need to understand the impact of waste management on greenhouse gas emissions. This review paper serves to provide an overview on the impact of landfilling (and its various alternatives) and composting on greenhouse gas emissions taking into account streamlined life cycle activities and the decomposition process. The review suggests greenhouse gas emissions from waste decomposition are considerably higher for landfills than composting. However, mixed results were found for greenhouse gas emissions for landfill and composting operational activities. Nonetheless, in general, net greenhouse gas emissions for landfills tend to be higher than that for composting facilities.     

城市生活垃圾代谢的研究进展

城市代谢是导致城市发展、能量生产和废物排放的社会、经济和技术过程的总和。生活垃圾管理系统是一类典型的、具备社会、经济、自然要素的复杂系统,它不仅同管理体制、技术水平和居民素质有关,也贯穿生产、消费、流通、还原过程,更和水体、土壤、大气、生物、矿产等自然环境紧密联系。综述了近年来基于城市生态系统代谢思路,在生活垃圾碳、重金属、营养元素和能量的城市代谢等方面的研究进展,分析了未来该领域研究需重点关注的方向。生活垃圾在城市生态系统中的能量流动、物质循环、代谢效率等方面的研究,可为生活垃圾管理系统的评价、规划、工程、管理研究提供科学基础。     

Ecological design applied

Over the past three decades ecological design has been applied to an increasingly diverse range of technologies and innovative solutions for the management of resources. Ecological technologies have been created for the food sector, waste conversion industries, architecture and landscape design, and to the field of environmental protection and restoration. The five case studies presented here represent applications of ecological design in five areas: sewage treatment, the restoration of a polluted body of water, the treatment of high strength industrial waste in lagoons, the integration of ecological systems with architecture, and an agriculturally based Eco-Park. Case #1 is an Advanced Ecologically Engineered System (AEES) for the treatment of sewage in Vermont, a cold climate. The facility treated 300 m³ per day (79,250 gallons per day) of sewage to advanced or tertiary wastewater standards, including during the winter months. A number of commercial byproducts were developed as part of the treatment process. Case #2 involved the treatment of a pond contaminated with 295 m³ per day (77,930 gallons per day) of toxic leachate from an adjacent landfill. A floating Restorer was built to treat the polluted pond. The Restorer was powered by wind and solar based energy sources. Over the past decade the pond has improved. There has been a positive oxygen regime throughout the water column, bottom sediments have been digested and the quality of the sediment chemistry has improved.The biodiversity of the macrobenthos of the pond has increased as a result of the improved conditions. Case #3 involved the treatment of 37,850 m³ per day (1 million gallons per day) of high strength waste from a poultry processing plant utilizing a dozen AEES Restorers. The technology has resulted in a 74% drop in energy requirements for treatment and has dramatically reduced the need for sludge removal. Currently, sludge degradation is proceeding faster than sludge accumulation. Case #4 includes several examples of buildings that utilize ecologically engineered systems to treat, recycle and permit the reuse of wastewater. The new Lewis Center for Environmental Studies at Oberlin College is a recent example of this trend. Case #5 describes the work that is leading to the creation of an urban, agriculturally based, Eco-Park in Burlington, Vermont. Waste heat from a nearby power station will provide year round climate control in a structure developed for food processing businesses, including a brewery, and for the onsite growth of diverse foods in integrated systems. We also describe a project to amplify the value of waste organic materials through biological conversion to high value products such as fish, flowers, mushrooms, soils amendments, and livestock and fish feeds. An ecologically designed fish culture facility will be an integral part of the Eco-Park complex. The project is intended to demonstrate the economic viability of integrative design in an urban setting and to address the important issue of locally based food production.     

Comparing technologies for municipal solid waste management using life cycle assessment methodology: a Belgian case study

Purpose

The present study aims at identifying the best practice in residual municipal solid waste management using specific data from Liège, a highly industrialized and densely populated region of Belgium. We also illustrate the importance of assumptions relative to energy through sensitivity analyses and checking uncertainties regarding the results using a Monte Carlo analysis.

Methods

We consider four distinct household waste management scenarios. A life cycle assessment is made for each of them using the ReCiPe method. The first scenario is sanitary landfill, which is considered as the base case. In the second scenario, the refuse-derived fuel fraction is incinerated and a sanitary landfill is used for the remaining shredded organic and inert waste only. The third scenario consists in incinerating the whole fraction of municipal solid waste. In the fourth scenario, the biodegradable fraction is collected and the remaining waste is incinerated. The extracted biodegradable fraction is then treated in an anaerobic digestion plant.

Results and discussion

The present study shows that various scenarios have significantly different environmental impact. Compared to sanitary landfill, scenario 4 has a highly reduced environmental impact in terms of climate change and particulate matter formation. An environmental gain, equal to 10, 37, or 1.3 times the impact of scenario 1 is obtained for, respectively, human toxicity, mineral depletion, and fossil fuel depletion categories. These environmental gains are due to energetic valorization via the incineration and anaerobic digestion. Considering specific categories, greenhouse gas emissions are reduced by 17 % in scenario 2 and by 46 % in scenarios 3 and 4. For the particulate matter formation category, a 71 % reduction is achieved by scenario 3. The figures are slightly modified by the Monte Carlo analysis but the ranking of the scenarios is left unchanged.

Conclusions

The present study shows that replacing a sanitary landfill by efficient incineration significantly reduces both emissions of pollutants and energy depletion, thanks to electricity recovery.     

Transforming the Cement Industry into a Key Environmental Infrastructure for Urban Ecosystem: A Case Study of an Industrial City in China

Under the dual pressure of environmental constraints and increasingly thin profit margins, the cement industry in China is in a predicament. To alleviate the environmental and the economic pressure of the cement industry and to tackle the problem of delayed environmental infrastructure construction, this article introduced an urban ecosystem in which the cement industry was transformed into an effective complement to environmental infrastructure. The Xinfeng Cement Industrial Park in China, which has a production capacity of 5 million tonnes per annum (Mt/a) of clinker, was chosen as a case study. Our methodology involved proposing technologies to develop an efficient cement plant‐centered urban ecosystem; evaluating its environmental and economic performance; identifying barriers in its promotion; and proposing supportive policies. Results showed that the city's waste recycling ratio rose from about 50% to 70%, saving 0.6 Mt/a of coal equivalent and reducing about 3.0 Mt/a of resulting carbon dioxide (CO₂) emissions. The life span of the city's landfill site was extended by about 30 years. The total investment was 3.2 billion yuan (about US$480 million), 1 with an average payback period of 3 years. The Xinfeng Cement Industrial Park was transformed from an energy‐intensive consumer and a significant CO₂ emitter to a key industrial waste recycler, a crucial municipal waste co‐processor, an important new building material supplier, and a potential energy producer. Last, the “not‐in‐my‐back‐yard” (NIMBY) effect from constructing new environmental infrastructure was also avoided.