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

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.

分类收集对我国城市生活垃圾处理处置的影响探析

城市生活垃圾分类收集是实现生活垃圾高效资源化和无害化处理的必然途径。垃圾分类制度的正式实行,使城市生活垃圾收运模式得到了优化,节约了填埋场库容,降低了填埋场失稳风险和焚烧烟气中的重金属含量。我国于2019年在全国范围内实施生活垃圾分类制度,全面推进了城市生活垃圾分类收集工作。分类收集对我国城市生活垃圾处理处置所产生的影响引起了业界广泛关注。通过文献调研,总结和分析了我国城市生活垃圾分类收集的现状及分类收集对生活垃圾不同处理处置方式的影响研究现状及进展,以期为我国更好地规划和管理生活垃圾处理处置及相关研究提供参考。

关于生活垃圾分类的市场化研究

生活垃圾分类是改善生态环境,提升居民文明素养的有效平台,开展生活垃圾分类具有深远意义。对生活垃圾分类收集市场产业化运作模式进行了分析,以问题为导向,建立统筹谋划,靶向失策,系统改革的工作思路,对城市开展生活垃圾分类收集市场化发展提供了理论依据。

规制背景下垃圾分类行为的影响因素研究

规制背景下个体的垃圾分类行为是城市垃圾分类效果的微观基础,因此垃圾分类行为的影响因素为人们所关注.依照计划行为理论,对垃圾分类的行为态度、主观规范、感知行为控制会影响垃圾分类行为.针对广州市高校学生的1155份有效调查问卷,利用结构方程模型对其数据进行分析,研究发现行为态度对垃圾分类行为无显著影响;主观规范对行为影响最大,其次是感知行为控制.个体的垃圾分类行为受室友的影响大于受家人的影响,而学校对垃圾分类行为设有奖惩制度对垃圾分类行为的预测作用最大.依据实证分析结果,可从以下方面来促进垃圾分类:首先,环境教育从认知教育转为垃圾分类引导、情景教育;其次,对城市生活垃圾分类可实施“奖惩”并提高规制强度;最后,利用群体对个体的垃圾分类行为规范的影响,可实施以小区、楼栋为单元的垃圾分类管理.

生活垃圾分类中神经网络样本不平衡研究

针对生活垃圾分类中存在的样本不平衡问题,本文基于实例分割模型Mask R-CNN神经网络展开研究,通过调整神经网络的损失函数和扩充数据集中的难分正样本来提升神经网络的检测精度。实验结果表明,该方法降低了数据不平衡对网络性能的影响,使生活垃圾的回收率得到了提升。

Characteristics of the stabilized/solidified municipal solid wastes incineration fly ash and the leaching behavior of Cr and Pb

Fly ash is a hazardous byproduct of municipal solid wastes incineration （MSWI）. An alkali activated blast fumace slag-based cementifious material was used to stabilize/solidify the fly ash at experimental level. The characteristics of the stabilized/solidified fly ash, including metal leachability, mineralogical characteristics and the distributions of metals in matrices, were tested by toxic characteristic leaching procedure （TCLP）, X-ray diffrac- tion （XRD） and scanning electron microscopy-energy dispersive spectrometer （SEM-EDS） respectively. Contin- uous acid extraction was utilized to extract metal ions and characterize their leaching behavior. The stabilization/ solidification procedure for MSWI fly ash demonstrates a strong fixing capacity for the metals by the formation of C- S-H phase, hydrated calcium aluminosilicate and ettringite. The stabilized/solidified fly ash shows a dense and homogeneous microstructure. Cr is mainly solidified in hydrated calcium aluminosilicate, C-S-H and ettringite phase through physical encapsulation, precipitation, adsorption or substitution mechanisms, and Pb is mainly solidified in C-S-H phase and absorbed in the Si-O structure.

Environment and economic feasibility of municipal solid waste central sorting strategy： a case study in Beijing

Although Beijing has carried out municipal solid waste （MSW） source separation since 1996, it has largely been ineffective. In 2012, a ＂Green House＂ program was established as a new attempt for central sorting. In this study, the authors used material flow analysis （MFA） and cost benefit analysis （CBA） methods to investigate Green House＇s environment and economic feasibility. Results showed that the program did have significant environmental benefits on waste reduction, which reduced the amount of waste by 34%. If the Green House program is implemented in a residential community with wet waste ratio of 66%, the proportion of waste reduction can reach 37%. However, the Green House is now running with a monthly loss of 1982 CNY. This is mainly because most of its benefits come from waste reduction （i.e., 5878 CNY per month）, which does not turn a monetary benefit, but is instead distributed to the whole of society as positive environmental externalities. Lack of government involvement, small program scale, and technical/managerial deficiency are three main barriers of the Green House. We, thus, make three recommendations： involve government authority and financial support, expand the program scale to separate 91.4 tons of waste every month, and use more professional equipment/technologies. If the Green House program can successfully adopt these suggestions, 33.8 tons of waste can be reduced monthly, and it would be able to flip the loss into a profit worth 35034 CNY.

Building momentum for sustainable behaviors in developing regions using Locally Managed Decentralized Circular Economy principles

Despite the current threat from climate change,plastic collecting in the world's oceans,and the steady loss of biodiversity,the world continually fails to take action with regard to our rapidly changing ecosystem.Unfortunately,waiting on governments to act is no longer a viable option.Rapid change is needed and the pace of diplomacy is simply too slow.Democratic governments are reactionary and taking action to solve future problems is not a priority,even as the threat of potential ecological catastrophe draws ever closer.Change is in the hands of individuals,and it is our decisions and behaviors that will influence the future of our planet and our ability to inhabit it.Therefore,building momentum for sustainable behavior must begin with individuals.The neoliberal approach to environmental protection posits that individuals are motivated by rational self-interest,and that economic incentives are necessary to achieve environmental goals.However,recent research suggests that monetary gain alone actually negatively impacts behavior,and often neglects the rural poor.As a result,models for projects designed to benefit the environment need more than just a monetary incentive,they must incorporate all three pillars of sustainability:environment,economy and society.One approach for building momentum for sustainable behavior with regard to municipal solid waste management,particularly in the developing world,is by implementing Locally Managed Decentralized Circular Economy(LMDCE)principles.This contribution will describe the role behavioral economics plays in the choices made by producers and consumers.The results of a case study on applying LMDCE principles in Uganda to manage waste plastic accumulation by conversion to fuel oil will be presented.

Modeling and motion control simulation of tendon based parallel manipulator translation mechanism for sensor based high value waste processing

A novel sorting system based on one degree of freedom (DOF) tendon based parallel manipulator (TBPM) for high value waste processing was presented and designed. In order to control the motion of loads, nonlinear state feed forward control algorithm in the tendon length coordinate was used. Considering the system redundancy and actuation behavior, algorithms of optimal tension distribution and forward kinematics were designed. Then, the simulation experiments of motion control were implemented. The results demonstrate that the proposed TBPM translation system performs robust capacities. It can transfer the loads 1 m away within 1.5 s. With further optimization, the translation duration can be further reduced to be about 1 s and the optimized translation is followed with 43.59 m/s2 maximum acceleration. The translation errors at the aim position remain below 0.4 mm.

考虑应力路径影响的垃圾土应力-应变特性

填埋场内垃圾土体存在多种应力状态(如压缩、拉伸、加载和卸载等),常规三轴试验和直剪试验难以全面进行模拟。为此,利用GDS三轴仪针对垃圾土重塑样开展9种不同应力路径下的三轴试验,深入研究分析应力路径对垃圾土应力-应变特性和屈服特性的影响,提出描述垃圾土应力-应变关系统一的数学模型,并得到p-q应力空间上垃圾土的屈服轨迹。通过与砂土进行比较,揭示应力路径对垃圾土中纤维材料加筋作用的影响规律。结果表明:对于σ_(3)≥0的压缩路径,垃圾土的应力关系曲线上翘,没有任何出现峰值或趋于渐近值的迹象,纤维材料起到的加筋作用最显著;对于σ_(3)<0的压缩路径,垃圾土的偏应力随轴向应变增加而增大,并逐渐趋于某定值,纤维材料起到的加筋作用较弱;对于Δ_(q)<0的伸长路径,垃圾土与砂土的应力-应变关系曲线近乎一致,纤维材料几乎不产生加筋作用。垃圾土中纤维材料的加筋作用与应力路径密切相关,研究成果为全面深入理解垃圾土的力学特性提供了依据。

生活垃圾中废旧塑料的机械分选技术研究进展

为了更加全面地了解生活垃圾中废旧塑料机械分选技术的研究进展,利用CiteSpace对生活垃圾中废旧塑料分选的相关文献进行关键词共现和聚类,同时结合相关专利文献从整体上呈现各分选技术研究应用的联系和发展,并基于塑料的物化特性介绍了国内外塑料机械分选技术的原理和特点,指出目前塑料分选存在准确率低、环境污染以及忽略成本效率等问题,展望了未来的研究方向。通过采用合适的分选技术可以实现废旧塑料的回收和后续资源化利用的目标,不仅可以带来经济效益,而且有显著的社会和环境效益。

基于固体回收燃料技术的城市固体废物特性分析

城市固体废物来源广泛,各种固体废物物理组成和化学成分差异较大。准确的废物产生源调查分析,为固废处理的规划、收运和综合利用提供基础的依据。固体回收燃料可真正实现固体废物的减量化和循环利用。本文以代表性城市固体废物为例,结合目前蓬勃发展的国内外固体回收燃料技术,调查不同源头固废,深入分析其总量、组分、含水率和热值等特性,进而为固废分类和制取固体回收燃料产品提供原始的分析。

Effect of the MgO/SiO_(2) ratio on MgO–silica binders solidifying MSWI fly ash

To improve the effect of MgO–SiO_(2) binders solidifying municipal solid waste incineration fly ash(MSWI FA),MSWI FA solidified bodies with five MgO/SiO_(2) ratios(0.41~3.77)were investigated.The leaching behavior of solidified bodies was evaluated by leaching toxicity tests and pH-dependent experiments.In addition,hydration products in solidified bodies were analyzed by thermodynamic modeling and microstructure characterizations.The results showed that the variation in the MgO/SiO_(2) ratio had a significant effect on the leaching toxicity of the solidified bodies,because it affected the leachate pH and the composition of the hydration products of the solidified bodies.The acid and alkali resistance of the MSWI FA was enhanced through solidification with MgO–SiO_(2) binders.MgO can improve the alkalinity of the solidified bodies and facilitate the chemical precipitation of heavy metals.Moreover,silica fume,an industrial waste,can serve as a cost-effective measure.Overall,MgO–SiO_(2) binders demonstrated great potential as promising candidates for encapsulating MSWI FA.

国内大中城市生活垃圾分类收集实施方案

作为"社会公害"之一的城市生活垃圾,是一种丰富的可再生资源,而实现城市垃圾资源化的关键是实施生活垃圾分类收集。详细分析了实施分类收集的6个前提条件。此外,还研究了我国城市生活垃圾分类收集的方法和实施程序。

上海市生活垃圾分选模式研究

采用孔径为120mm，40mm和mm的三种手动筛，对生活垃圾筛分，并对筛分后生活垃圾分类，通过对其质量和含量的测定，得出如下结论：粒径大于120mm范围内的生活垃圾中，有资源化潜力的组分为塑料、有机物、纸类、包装物及玻璃；粒径为40～120mm范围内生活垃圾中，有资源化潜力的组分为有机物、塑料、玻璃、金属和包装物；粒径为8～40mm范围内的生活垃圾，只要将玻璃分离开来，可以直接生物处理；而粒径小于8mm的生活垃圾，可以直接生物处理．根据这个实验结果，为上海市生活垃圾制定了一条机械分选流程．

北京市生活垃圾管理现状分析研究

综合分析了国外垃圾的管理经验,综述了北京市生活垃圾管理现状,指出了垃圾管理中存在的问题,提出了北京市生活垃圾管理上的改进建议。

城市生活垃圾风力分选效率研究

为了探索城市生活垃圾循环利用和处置,应用流体力学的基本原理,提出了城市生活垃圾风力分选流场的数学模型,并采用流体力学分析软件FLUENT进行数值模拟,发现影响风力分选效果的最主要的因素是城市生活垃圾各组分的密度和气流的流动速度。

城市生活垃圾筛分性质的研究

城市生活垃圾资源化已成为研究生活垃圾处理的热点问题，而从技术和经济方面考虑，并不是所有可资源化的生活垃圾都能够进行资源化利用。本实验运用120mm、40mm和8mm孔径的手动筛对城市生活垃圾进行筛分，然后进行称重和分类，研究粒径在大于120mm、40～120mm、8～40mm及小于8mm范围内生活垃圾的种类，对资源化利用价值较大的物质种类作出分析和判断，并依据此结果给出了城市生活垃圾机械分选的流程，从而为进一步研究经济、实用、合理的机械分选、了解城市生活垃圾中有资源化潜力的物质打下基础。

城市生活垃圾综合处理前分选系统设计

本文以江油市城市生活垃圾处理厂为工程实例 ,介绍了垃圾前分选系统中的垃圾储料车间、行车与抓斗、垃圾上料机构、双层振动筛以及人工分选平台的工艺设计参数及设计依据 ,并在此基础上提出了该系统的改进建议。

基于源头提质制RDF中垃圾机械分选效率研究

城市生活垃圾的产量与日俱增,对现已产生的生活垃圾,最好的办法是回收其中的物质和能源,即垃圾资源化,实现垃圾资源化的首要问题就是垃圾的源头分类或提质。但是由于我国人口众多、居民的环境意识差、垃圾处于混合收集等原因,造成了我国源头分类难的问题。文章提出了垃圾按质分为干湿两类,然后再把干湿两类分别处理,其中干组分经过人工分选和机械分选后,进行破碎成型,制备RDF燃料;针对这种源头提质制备RDF环节中机械分选的效率进行研究,分析了滚筛、滚筒、风机等机械设备对分选效率的影响,最后得出最佳的机械分选参数,极大地优化了机械分选过程,起到了在制备RDF前处理过程中源头提质的作用。