活性污泥吸附预处理重油裂化制气废水

利用剩余活性污泥对含有高浓度芳香族化合物的重油裂化制气废水进行预处理的研究并提出了合适的吸附条件。结果表明，活性污泥吸附预处理对COD和悬浮物有明显的去除效果，而且可以提高废水BOD5／COD的比值，另外还有降解芳香族化合物的作用，使进入生物处理系统的废水的可生物降解性有明显的改善。这一方法为利用普通废水生物处理系统中产生的剩余活性污泥来预处理难降解的工业废水提供了一条有效的途径。     

城市垃圾处理方式——垃圾焚烧炉与WtE型炉排

对于以垃圾为燃料的能量回收电厂,炉排必须保证垃圾在其上有足够长的停留时间,以使燃烧充分并符合环保排放标准.以瑞士为主的ABB集团所属WtE环保设备公司,开发的水平布置、以双向运动推力炉排为特征的垃圾焚烧炉,已被成功地证明具备上述性能要求.该炉排应用于世界各地许多垃圾焚烧站,每天焚烧垃圾总量约为15000吨.垃圾能量回收电厂包括一套复杂的设备,从垃圾的进料并在炉排上燃烬,到热量回收,烟气清洗一整套过程.监视这一全过程就是电厂综合管理的内容.由于所有设备应看成一个整体,从设计到施工有必要由同一公司完成.这一手段将保证电厂有最大的运行可靠性,并符合环保规程的排放要求.     

芦苇制浆废水的生态工程处理

本文主要讨论了生态工程处理芦苇制浆中段废水的工艺流程及其主要组成部分稳定塘和苇田的设计参。通过对工程预期处理效果和生态经济效益分析，认为在可供利用的大片苇田，运用生态工程处理纸浆废水，不仅可以达到控制污染的目的，而且可以取得较好的生态经济效益。     

利用矿化垃圾层预防和控制渗滤液导排系统堵塞

在卫生填埋场中,垃圾渗滤液导排系统堵塞普遍存在,悬浮固体形成的物理堵塞、有机物降解和金属离子沉淀导致的生物-化学堵塞是引起导排系统堵塞的关键因素.本文构建了"矿化垃圾+砾石层导排"的渗滤液下渗装置,通过矿化垃圾预处理渗滤液中悬浮固体和有机物以控制导排系统发生的物理和生物-化学堵塞.结果表明,在矿化垃圾层,渗滤液中化学需氧量(COD)和悬浮固体(SS)去除较多,去除率分别达到了85%和87%,并且Ca²⁺浓度也出现了波动较大的现象;然而,渗滤液在砾石层下渗过程中,其COD、SS和Ca²⁺浓度保持稳定.并且,砾石层可排水孔隙率在长期运行的过程中没有明显变化,表明渗滤液在砾石导排层没有形成明显的沉淀.与此同时,在没有添加矿化垃圾的对照组发现,砾石层可排水孔隙率减少最多的区段是渗滤液的进水点位(可排水孔隙率减少达到了53%),即渗滤液有机负荷最大处的饱和砾石层堵塞最为严重,其无机堵塞物主要是碳酸钙等.因此,在渗滤液流入砾石层前,采用矿化垃圾层部分饱和的方式对渗滤液中有机物和悬浮固体进行预处理,可以预防和控制渗滤液在砾石层形成沉淀堵塞.研究为填埋场的运行管理渗滤液导排系统堵塞提供了新的思路和方法.     

Fenton氧化处理垃圾膜滤浓缩液

本文以混凝预处理后的上海老港垃圾填埋场渗滤液纳滤浓缩液为研究对象,采用混凝预处理、Fenton氧化法和生化法相结合的工艺对其进行处理,将其出水COD从2930 mg·L~(-1)降至100 mg·L~(-1)以下.采用响应曲面法研究了Fenton氧化法处理经过混凝预处理纳滤浓缩液过程中,各个影响因素之间的相互作用关系,并确定了最佳实验条件,即FeSO_4·7H_2O投加量为62.5 mmol·L~(-1)、H_2O_2投加量为121.8 mmol·L~(-1)、初始pH 3.0.在此条件下,Fenton氧化法可使混凝预处理出水的COD降低39.0%.进一步研究表明,Fenton氧化后纳滤浓缩液中芳香环类污染物减少、腐殖化程度降低.经过3 h的Fenton氧化法处理后,BOD5/COD从纳滤浓缩液原液的0.02上升到0.29.将垃圾渗滤液纳滤浓缩液Fenton氧化法处理后出水与垃圾填埋场渗滤液的纳滤出水1∶1混合,进行序批式活性反应器(SBR)处理,在水力停留时间为2 d时,出水COD可降低至96.0 mg·L~(-1).     

脱氮-混凝气浮-UASB-接触氧化法处理垃圾填埋渗滤液

设计了一套“脱氮-混凝气浮-UASB-接触氧化”工艺，对南京某垃圾场的垃圾渗滤液进行处理，经过半年的稳定运行实践，使处理后出水的各项指标完全达到国家《污水综合排放标准》(GB8978-96)二级标准。对废水处理系统的工艺作了简单介绍，并对系统的调试、运行过程进行了技术总结。由于运行稳定、处理成本较低、易于管理，故该工艺是处理高氨氮、高浊度垃圾渗滤液的有效方法。     

城市生活垃圾渗滤液土地处理的模拟研究

通过静态与动态试验以及小试,从5种土壤中筛选出适合重庆地区垃圾渗滤液土地处理的基质土壤,确定了土地渗滤和芦苇湿地等两组土地处理系统净化城市垃圾渗滤液的有关参数,模拟处理结果表明垃圾渗滤液经两级土地处理后,春氨氮和CODcr的去除率均达到90%以上,出水水质达到国家一级排放标准。     

垃圾渗滤液的Fenton氧化预处理研究

采用Fenton氧化法对垃圾渗滤液进行预处理,考察了渗滤液初始pH值、H2O2和FeSO4.7H2O投加量、H2O2/Fe2＋投加的物质的量比及氧化反应时间等对Fenton氧化处理效果的影响,获得Fenton氧化处理垃圾渗滤液的最佳工艺条件：初始pH=3.0,H2O2投加量为5.0 mL.L-1,FeSO4.7H2O投加量为3.48 g.L-1,H2O2/Fe2＋物质的量比为4-1,反应时间为1.5 h。最佳条件下处理后垃圾渗滤液COD为5 220 mg.L-1,COD去除率达57.8%。凝胶渗透色谱和三维荧光光谱分析结果表明,垃圾渗滤液中主要含有腐殖酸类大分子物质,经Fenton氧化后降解变成小分子化合物。     

城市生活垃圾处理技术现状与管理对策

近年来,我国城市生活垃圾产生量每年以约10%的速度迅猛增长,而城市生活垃圾处理能力发展相对滞后。客观评述城市生活垃圾常用的填埋、焚烧、堆肥3种处理技术的优缺点和在国内的应用现状,并针对城市生活垃圾在收运、处理以及管理等环节中存在的突出问题,提出了明确的建议与措施：首先,完善相关法规政策,实施分类收集,加强源头控制;其次,创新管理体制,推行市场化运作机制,政府加强政策引导和监督;再次,按照＂谁污染,谁付费＂的原则,建立健全垃圾收费体系;最后,充分利用各种媒介,加大宣传力度,提高公众环保意识。同时,还探讨了城市生活垃圾处理技术发展的趋势。焚烧处理将是今后一段时期我国最有发展潜力的技术,气化熔融焚烧技术是一种高效资源化、污染物接近零排放的新型焚烧技术;生物反应器填埋技术可减少渗滤液处理量、降低垃圾处理成本,具有广阔的发展前景;堆肥技术可作为焚烧或填埋之前的预处理手段;城市生活垃圾综合处理集多种处理技术的优点于一体,在节约处理成本,提高经济效益的同时,实现了垃圾的减量化、资源化、无害化,是未来我国生活垃圾处理的优先发展方向。     

《工业和城镇污水土地处理系统手册》简介

美国Sherwood C.Reed和Ronald W.Crites两位学者所著时《工业和城镇污水土地处理系统手册》(Handbookof Land Treatment Systems for Industrial and Muni-cipal Wastes)一书,全面阐明了工业废水和城镇污水土地处理系统的整套设计步骤和标准。自七十年代以来,大量的研究不仅证实了污水土地处理系统的有效性和可靠性,而且还证实这种处理手段所需的建设投资、运转费用和能源需求量都大大低于常规的污水处理手段。但是,直至今日在许多标准的工程设计书中只是将污水土地处理问题一带而过,或者干脆不提。这本书的宗旨正是为了弥补这一不足。     

Effectiveness of aerobic pretreatment of municipal solid waste for accelerating biogas generation during simulated landfilling

Effect of aerobic pretreatment of MSW on landfill gas generation was investigated. Volatile solid (VS) loss of MSW is an effective and comparable indicator. Chinese MSW requires at least a reduction of VS about 27% (w/w) prior to disposal. Aerobic pretreatment of MSW reduced lag phase more than 90% before methanogenesis. Aerobic pretreatment degree influences quantity of gas generation. This study evaluates the effectiveness of aerobic pretreatment of municipal solid waste (MSW) on reducing lag phase and accelerating biogas generation. Aerobic pretreatment degree (APD) was determined on the basis of reduction in volatile solids (VS) on a wet weight basis. In this study, intermittent aeration (IA) was applied to three reactors as a main aeration mode; since a single reactor was operated under continuous aeration mode. However, the purpose of the experiment was to reduce VS content of waste, irrespective of the comparison between aeration modes. Fresh MSW was first pretreated aerobically with different aeration rates (10, 40, 60 and 85 L/min/m³) for the period of 30–50 days, resulting in VS-loss equivalent to 20%, 27%, 38% and 53% on w/w basis for the wastes A1, A2, A3 and A4, respectively. The cumulative biogas production, calculated based on the modified Gompertz model were 384, 195, 353, 215, and 114 L/kg VS for the wastes A0, A1, A2, A3 and A4, respectively. Untreated waste (A0) showed a long lag phase; whereas the lag phases of pretreated MSW were reduced by more than 90%. Aerobically pretreated wastes reached stable methanogenic phase within 41 days compared to 418 days for untreated waste. The waste mass decreased by about 8% to 27% compared to untreated MSW, indicative that even more MSW could be placed in the same landfill. The study confirmed the effectiveness of aerobic pretreatment of MSW prior to landfilling on reducing lag phase and accelerating biogas generation.     

Carbon discharge through municipal solid waste in Haikou,China

With rapid urban development, municipal solid waste (MSW) has become a pressing issue. Estimation of carbon discharge through municipal solid waste provides a way to assess environmental load of solid waste from the viewpoint of the carbon cycle. With few studies on carbon research and provides insights into human impacts on the carbon cycle. Based on a comprehensive fieldwork investigation of a typical Chinese tourist city – Haikou City, Hainan Island – the characteristics of MSW carbon discharge and human activities that influenced it were analysed. The results indicated that, in 2001, the total carbon discharge from 261.9 Gg of MSW was 105.1 GgC per year, and 174.6 kgC per capita per annum. Carbon is discharged in the form of food scraps (24%), plastics (20%), wood (17%), fabrics (14%), paper (13%), and dust and stone (12%). If landfill received all the waste, 4.7% of MSW carbon would be transformed into methane, with a value of 4.9 GgC. Between 1991 and 1999, Haikou's per capita MSW carbon discharge increased by 59.9%, and total MSW carbon discharge increased by 124.9%. MSW carbon discharge in Haikou is significantly affected by the growth of residential expenditure and urbanisation. Local characteristics of tourism also influence Haikou's MSW carbon discharge, not only in terms of its yearly variation, but also its monthly variation. Integrating data on carbon discharge with carbon consumption will provide a systematic view of the carbon metabolism in urban ecosystems, and further insights into the generation of urban environmental pollution.     

Toward separation at source: Evolution of Municipal Solid Waste management in China

Municipal Solid Waste (MSW) management in China has been transitioning from a mixed collection and treatment system to a separated collection and treatment system. The continuous rise of MSW treatment capacity and the optimization of technology structure provided basic facility support for China to promote MSW separation at source. China preferred a four-type separation system. Regulated recycling should be enhanced to improve the efficiency and sustainability of recycling industry. As food waste is the main composition of MSW in China, 20%–30% of the food waste diversion and land application could maximize the comprehensive environmental performance. Incineration is to be the pillar technology in MSW separated treatment system in China.     

Assessment of key parameters in municipal solid waste management: a prerequisite for sustainability

Municipal solid waste management was studied for 1 year in a representative urban area of Lahore city for environmental sustainability. The effects of financial status of the household and the seasonal variations on generation rate and compositions of municipal solid waste (MSW) were determined. MSW generation rate and the economic status of the households were positively correlated (p < 0.05). Seasonal variations observed were significant only for organics (p = 0.001), plastics (p = 0.008) and food waste fractions (p = 0.009) in MSW. Response surface regression model developed and analysed by Minitab-15® showed that the interaction of season and different economic zones of the town on the MSW generation rate was non-significant (p = 0.334). Elemental and heating value analyses of the mixed organic fractions in kitchen waste had carbon 47.93%, hydrogen 6.20%, nitrogen 2.24%, sulphur 0.23%, oxygen 39.01%, and C and N ratio 27.78. Findings concluded that food waste was 56% of total MSW with 71.03% moisture content and a modest heating value of 5566 J/g. Existing temporary storage capacity of MSW is 51% of the total MSW generated considering the weighted MSW generation rate of 0.57 kg/person/day calculated in this study. Composting could be a possible final disposal option due to high moisture and organic content and can be studied in future research. Development of a transfer station, introduction of home composting programmes and awareness towards proper segregation and reduction of waste at the household level is suggested to attain sustainability in the MSW management system.     

Research on low emission MSW gasification and melting system

In order to eliminate secondary pollution caused by municipal solid waste (MSW) incineration, a MSW gasification and melting process is proposed. The process is expected to reduce the emission of pollutants, especially heavy-metals and dioxins. In this paper, the combustible components of MSW and simulated MSW were gasified in a lab-scale fluidized bed at 400°C–700°C when the excess air ratio (ER) was between 0.2 and 0.8. The experimental results indicated that the MSW could be gasified effectively in a fluidized bed at approximately 600°C–700°C when excess air ratio was 0.2–0.4. The melting characteristics of two typical fly ash samples from MSW incinerators were investigated. The results indicated that fly ash of pure MSW incineration could be melted at approximately 1,300°C and that of MSW and coal co-combustion could be melted at approximately 1,400°C. When temperature was over 1,100°C, more than 99.9% of the dioxins could be decomposed and most of the heavy-metals could be solidified in the slag. Based on the above experiments, two feasible MSW gasification and melting processes were proposed for low calorific value MSW: (1) sieved MSW gasification and melting system, which was based on an idea of multi-recycle; (2) gasification and melting scheme of MSW adding coal as assistant fuel.     

Development of machine learning multi-city model for municipal solid waste generation prediction

● A database of municipal solid waste (MSW) generation in China was established. ● An accurate MSW generation prediction model (WGMod) was constructed. ● Key factors affecting MSW generation were identified. ● MSW trends generation in Beijing and Shenzhen in the near future are projected. Integrated management of municipal solid waste (MSW) is a major environmental challenge encountered by many countries. To support waste treatment/management and national macroeconomic policy development, it is essential to develop a prediction model. With this motivation, a database of MSW generation and feature variables covering 130 cities across China is constructed. Based on the database, advanced machine learning (gradient boost regression tree) algorithm is adopted to build the waste generation prediction model, i.e., WGMod. In the model development process, the main influencing factors on MSW generation are identified by weight analysis. The selected key influencing factors are annual precipitation, population density and annual mean temperature with the weights of 13%, 11% and 10%, respectively. The WGMod shows good performance with R² = 0.939. Model prediction on MSW generation in Beijing and Shenzhen indicates that waste generation in Beijing would increase gradually in the next 3–5 years, while that in Shenzhen would grow rapidly in the next 3 years. The difference between the two is predominately driven by the different trends of population growth.     

Development and prospects of municipal solid waste (MSW) incineration in China

With the lack of space for new landfills, municipal solid waste (MSW) incineration is playing an increasingly important role in municipal solid waste management in China. The literatures on certain aspects of incineration plants in China are reviewed in this paper, including the development and status of the application of MSW incineration technologies, the treatment of leachate from stored MSW, air pollution control technologies, and the status of the fly-ash control method. Energy policy and its promotion of MSW-to-energy conversion are also elucidated.     

衡阳市城市垃圾处理现状及改进建议

城市垃圾数量大、成分复杂,如果不好好处理会对环境和人体健康造成很大危害.就城市垃圾的危害及垃圾处理现状进行了分析,并对衡阳市垃圾处理提出改进建议.参6.     

MSWNet: A visual deep machine learning method adopting transfer learning based upon ResNet 50 for municipal solid waste sorting

● MSWNet was proposed to classify municipal solid waste. ● Transfer learning could promote the performance of MSWNet. ● Cyclical learning rate was adopted to quickly tune hyperparameters. An intelligent and efficient methodology is needed owning to the continuous increase of global municipal solid waste (MSW). This is because the common methods of manual and semi-mechanical screenings not only consume large amount of manpower and material resources but also accelerate virus community transmission. As the categories of MSW are diverse considering their compositions, chemical reactions, and processing procedures, etc., resulting in low efficiencies in MSW sorting using the traditional methods. Deep machine learning can help MSW sorting becoming into a smarter and more efficient mode. This study for the first time applied MSWNet in MSW sorting, a ResNet-50 with transfer learning. The method of cyclical learning rate was taken to avoid blind finding, and tests were repeated until accidentally encountering a good value. Measures of visualization were also considered to make the MSWNet model more transparent and accountable. Results showed transfer learning enhanced the efficiency of training time (from 741 s to 598.5 s), and improved the accuracy of recognition performance (from 88.50% to 93.50%); MSWNet showed a better performance in MSW classsification in terms of sensitivity (93.50%), precision (93.40%), F1-score (93.40%), accuracy (93.50%) and AUC (92.00%). The findings of this study can be taken as a reference for building the model MSW classification by deep learning, quantifying a suitable learning rate, and changing the data from high dimensions to two dimensions.     

21世纪城市生活垃圾生态化处理展望

我国目前由于管理,经济,技术以及公众环境意识的薄弱,城市生活垃圾已成为污染环境的一大公富,大致使大量有用资源浪费,就生态城市建设中垃圾生态化处理的重要性和对策进行了探讨,以期推动我国城市生活垃圾生态化处理和生态城市建设工作的开展。