Intended process water management concept for the mechanical biological treatment of municipal solid waste

Accumulating operational experience in both aerobic and anaerobic mechanical biological waste treatment （MBT） makes it increasingly obvious that controlled water management would substantially reduce the cost of MBT and also enhance resource recovery of the organic and inorganic fraction. The MBT plant at Gescher, Germany, is used as an example in order to determine the quantity and composition of process water and leachates from intensive and subsequent rotting, pressing water from anaerobic digestion and scrubber water from acid exhaust air treatment, and hence prepare an MBT water balance. The potential of, requirements for and limits to internal process water reuse as well as the possibilities of resource recovery from scrubber water are also examined. Finally, an assimilated process water management concept with the purpose of an extensive reduction of wastewater quantity and freshwater demand is presented.

Emergy Evaluation of Treatment Methods for Solid Medical Waste in Bujumbura-Burundi

Introduction: Treatment of solid medical waste (SMW) is a complex task requiring the proper practices with specific treatment methods corresponding to each type of SMW during pretreatment and final treatment. This study targeted three treatment methods identified as the main used by the majority of health care facilities (HCFs) and treating a large amount of SMW. It aimed: 1) to evaluate the current practices by calculating the emergy investment and emergy costs that are required to treat one ton of SMW through the three treatment methods and 2) to evaluate and compare better technologies and provide policy suggestions for the final treatment of SMW in Burundi. Materials and Methods: This study used the emergy methodology to evaluate the relative efficiencies of three treatment methods used for to treat SMW in twelve HCFs in Bujumbura. Results and Conclusion: The total emergy input was 1.36E+20 seJ/yr, 3.54E+17 seJ/yr, and 1.681E+18 seJ/yr for low temperature incinerator, landfill and organic pit, respectively. Conclusion: Rapid improvement of organic pit by ensuring its maintenance, the gradual replacement of low temperature incinerator by high temperature incinerator with air control pollution and landfill by sanitary landfill are highly recommended by respecting its maintenance (fence, roof and monitoring evaluation) for reducing the risk.

Research achievements and application in anaerobic treatment of organic solid wastes—A review

Anaerobic digestion is a good method, which possesses the optimal combination of volume reduction, probability of success and potential for resource and energy recovery. However, relatively little research has been done on the anaerobic digestion of organic solid wastes (OSW), especially in China. However, different substrates, start-up conditions, micro-organisms, processing technologies, pre-treatment methods could influence the result of anaerobic digestion. Anaerobic treatment of municipal OSW is less than that of wastewaters because some problems and obstructions need to be solved. Meanwhile, the application of anaerobic digestion of OSW is also discussed in the present paper.

Oyster Shell Recycling and Bone Waste Treatment Using Plasma Pyrolysis

Investigations on the recycling plasma pyrolysis technique are presented in 25 kW was employed for the experiments. of oyster shells and bone waste treatment using the this paper. A arc based plasma torch operated at Fresh oyster shells were recycled using the plasma torch to convert them to a useful product such as CaO. Bone waste was treated to remove the infectious organic part and to vitrify the inorganic part. The time required for treatment in both cases was significantly short. Significant reduction in the weight of the samples was observed in both cases.

Microstructures and thermal properties of municipal solid waste incineration fly ash

To analyze the feasibility of utilization of thermal technology in fly ash treatment,thermal properties and microstructures of municipal solid waste incineration(MSWI) fly ash were studied by measuring the chemical element composition,specific surface area,pore sizes,functional groups,TEM image,mineralogy and DSC-TG curves of raw and sintered fly ash specimens.The results show that MSWI fly ash particles mostly have irregular shapes and non-typical pore structure,and the supersonic treatment improves the pore structure;MSWI fly ash consists of such crystals as SiO2,CaSO4 and silica-aluminates,and some soluble salts like KCl and NaCl.During the sintering process,mineralogy changes largely and novel solid solutions are produced gradually with the rise of temperature.Therefore,the utilization of a proper thermal technology not only destructs those persistent organic toxicants but also stabilizes hazardous heavy metals in MSWI fly ash.

Treatment of Bone Waste Using Thermal Plasma Technology

Daily meat consumption produces a lot of bone waste, and dumped bone waste without treatment would result in environmental hazards. Conventional treatment methods of waste bones have some disadvantages. Herein, an investigation of bone waste treated using thermal plasma technology is presented. A high-temperature plasma torch operated at 25.2 kW was used to treat bone waste for seven minutes. The bone waste was finally changed into vitric matter and lost 2/3 of its weight after the treatment. The process was highly efficient, economical, convenient, and fuel-free. This method could be used as an alternative for disposal of bone waste, small infectious animals, hazardous hospital waste, etc.

Modeling Municipal Solid Waste Management in Africa: Case Study of Matadi, the Democratic Republic of Congo

The purpose of this article is to present the key elements for best performance and profitability of Municipal Solid Waste (MSW) management in a low-income city. The research provides an overview of methods and models for integrated planning of a two-phase program: MSW collection and transportation, and MSW treatment. We present the case study of Matadi (the Democratic Republic of Congo) that has a low level of the MSW management compared to other African cities. We develop a spreadsheet model for collection and transportation of MSW which is relevant for low-income cities and enables determining the waste collection fee. A CDM decay model is used to predict the GHG emissions in disposal site. The MSW treatment plant in case of Matadi is evaluated. For the anaerobic digestion technology selected as appropriate for this plant, the key factors that ensure profitability of the plant are as follows: tipping fee from the municipality (19% of total revenue), amount of carbon credits which can sum up to 16% of the total revenue, expansion of waste collection range from 25 to 50 km. The methods of this study can be used for solving waste problem in other low-income cities where the budget for municipal services is scanty, particularly when starting from a very low level of MSW management.

Metagenomic insights into microorganisms and antibiotic resistance genes of waste antibiotic fermentation residues along production,storage and treatment processes

Antibiotic fermentation residue(AFR)is nutrient-rich solid waste generated from fermentative antibiotic production process.It is demonstrated that AFR contains high-concentration of remaining antibiotics,and thus may promote antibiotic resistance development in receiving environment or feeding farmed animals.However,the dominate microorganisms and antibiotic resistance genes(ARGs)in AFRs have not been adequately explored,hampering understanding on the potential antibiotic resistance risk development caused by AFRs.Herein,seven kinds of representative AFRs along their production,storage,and treatment processes were collected,and multiple methods including amplicon sequencing,metagenomic sequencing,and bioinformatic approaches were adopted to explore the biological characteristics of AFRs.As expected,antibiotic fermentation producer was found as the predominant species in raw AFRs,which were collected at the outlet of fermentation tanks.However,except for producer species,more environment-derived species persisted in stored AFRs,which were temporarily stored at a semi-open space.Lactobacillus genus,classified as Firmicutes phylum and Bacilli class,became predominant bacterial taxa in stored AFRs,which might attribute to its tolerance to high concentration of antibiotics.Results from metagenomic sequencing together with assembly and binning approaches showed that these newly-colonizing species(e.g.,Lactobacillus genus)tended to carry ARGs conferring resistance to the remaining antibiotic.However,after thermal treatment,remaining antibiotic could be efficiently removed from AFRs,and microorganisms together with DNA could be strongly destroyed.In sum,the main risk from the AFRs was the remaining antibiotic,while environment-derived bacteria which tolerate extreme environment,survived in ARFs with high content antibiotics,and may carry ARGs.Thus,hydrothermal or other harmless treatment technologies are recommended to remove antibiotic content and inactivate bacteria before recycling of AFRs in pharmaceutical industry.

A Sustainable Strategy for Spent Cathode Carbon Blocks Hazardous Waste Recycling Using Binary Molten Salt Thermal Treatment

Waste-to-Energy treatment is a promising path to environment and energy management in the future.This work detailed a binary molten salt thermal treatment methodology for the detoxification of spent cathode carbon block(SCCB)waste and the recycling of carbonaceous materials.The thermal behavior of SCCB and SCCB blended with molten salts was investigated.It was found that the NaCl-Na_(2)CO_(3)binary molten salts significantly contributed to reducing pyrolysis onset temperature by 334.3 K compared to that of SCCB itself(i.e.,activation energy of pyrolysis reaction was reduced from 4.24×10^(5)to 2.30×10^(5)J/mol),thus helping to lower thermal treatment energy consumption.With the addition of binary molten salts,the residue after thermal treatment in a horizontal tube furnace experiment was separated into two layers.The bottom-layer residue was mainly composed of molten salts.The fluorine content in the form of NaF and CaF_(2)of top-layer residue was reduced significantly while the carbon content remained unchanged.Specifically,the leaching concentration of fluoride ion was decreased from 4620 mg/L to 856 mg/L.It is noted that the NaF and CaF_(2)can be removed through water-leaching and hydrothermal acid-leaching methods and thus the carbonaceous materials with a calorific value of 17.5 MJ/kg were obtained.

Comparative Study on Distributed Waste Pyrolysis Cold Emission Energy Station and Incineration Power Generation

The proper terminal disposal of organic solid waste such as domestic waste is a worldwide issue.Landfill covers a large area,with limited capacity,and a single landfill will be filled one day;incineration is costly to build and operate.These methods all need to transfer and centralized treatment,and secondary pollution is difficult to control,against the purification law of the nature."NIMBY effect"is very serious,and the social cost of treatment is increasing,becoming a heavy financial burden."The Distributed Waste Pyrolysis Cold Emission Energy Station"developed by Hunan Zhongzhou Energy-Saving Technology Co.,Ltd.overcomes these disadvantages and constructs a more appropriate environmental economic industrial chain for the treatment of organic solid waste such as urban and rural household waste.Based on its technical characteristics,this paper compares it with waste incineration power generation project in the aspects of secondary pollution control,treatment effect,energy utilization,investment and operation economy,etc.

一流课程建设背景下固体废物处理改革与探索

固体废物处理是环境工程专业的核心课程。为了贯彻落实教育部一流本科课程建设计划以及创新型人才培养的要求,天津大学固体废物处理课程教学团队一直致力于该课程质量的持续提升。针对该课程教学中的难点,在教学理念与方法、教学资源建设、课程考核方式、教学团队建设等方面进行了一系列改革探索和实践,并取得了良好的成效,加强了科研、产业与本科教学的深度融合,提升了本科生的实践创新能力,有利于培养具有“家国情怀”的固废处理领域复合型人才。

城市固体废弃物资源化共生网络脆弱性研究——基于某市无废城市建设的案例分析

城市固体废弃物资源化共生网络是实现无废城市的最佳途径,城市固体废弃物共生网络容易受多种因素的影响,包括再生资源需求萎缩或标准的变更,突破性技术的出现以及由于市场、技术、政策中存在的信息不对称引发的利益冲突等。资源化共生网络系统的动荡或非正常运行,制约了无废城市的建设和发展。基于此,研究梳理了中国无废城市的建设背景及发展过程,以国内某城市为例,介绍了该市无废城市建设的基本情况和成果,构建了固体废弃物资源化共生网络,并运用MATLAB程序进行了仿真实验。研究表明:该市的城市固体废弃物共生网络尚未形成嵌套模式,不同产业链的共生模式存在差异,并从推进信息化建设、关注核心企业运行和开展技术创新3个方面对城市固体废弃物资源化共生网络的脆弱性进行了治理。

《固废法》背景下皮革行业危险废弃物处理现状研究

分析了《固废法》中关于制革危废的基本内容及豁免条件,并结合含铬危废的特点,对企业委托处置和自行资源化利用等方式进行了横向比较,阐述了制革危废资源化利用技术的新发展方向,为企业更好地了解制革行业环保政策和技术路径进行前期铺垫。

固体废物资源化技术的研究与应用

本文旨在探讨固体废物资源化技术的研究与应用,重点关注了皮革制造业中的环保科技创新。通过对废弃皮革和废皮革工业废物的处理和再利用,本研究展示了如何将废物转化为宝贵的资源,并减少对自然资源的依赖。本文还介绍了一系列废物资源化技术,包括废皮革的化学处理、物理分离和生物降解等方法,考察了这些技术在实际生产中的应用,以及对环境保护和可持续发展的潜在影响。本文的研究结果将有助于推动皮革制造业的绿色转型,从而减少废物排放,降低生产成本,提高资源利用效率。

异型仿生艺术建筑数字化绿色建造技术研究与实践

随着中国经济的快速发展和建筑业的转型升级,“双碳”战略的落地促使各行业加快产业转型。由新西兰建筑设计师Fred先生设计、位于深圳的玛丝菲尔总部一期工程、二期工程,其结构体系利用大自然经过亿万年进化的仿生学原理,运用生物力学的智慧实现薄壳、大跨结构的最优解。同时项目在建筑材料的选用上进行了创造性的尝试,回收建筑废弃物作为装修用材,在建筑固废处理方面提供了新思路。仿生艺术建筑独特结构和装饰的设计表达及结构验算迫切需要采用数字建造技术来实现,真正实现BIM正向设计。我司通过采用数字建造技术结合工程实际解决测量定位、产品加工、现场施工等一系列困难,打造了一座集仿生、绿色为一体的办公综合体。

不同管理阶段生活垃圾处理处置碳减排潜力研究——以厦门市为例

我国快速城市化带来了大量的城市生活垃圾。为了破解“垃圾围城”的普遍性难题,我国不断完善生活垃圾管理体系,经历了以填埋为主的无害化、以焚烧为主的无害化和减量化、垃圾强制分类在全国主要城市的全面推广、分类垃圾综合处理处置等不同发展阶段。以厦门市为例,分析不同生活垃圾管理阶段的碳排放特征。结果表明:厦门市2000—2009年(无害化阶段)的碳排放总量由25.49万t直线上升至76.38万t,年均增长13.19%;2010—2016年(无害化和减量化阶段)由于填埋气收集效率提升和持续推进垃圾焚烧减量,吨垃圾碳排放强度逐年下降,但排放总量仍然从27.95万t增长至49.30万t;2017年至今全市推行垃圾四分类并开展餐厨垃圾分类和低值可回收物试点,碳排放强度从324.74 kg/t下降至178.11 kg/t,其中每分出1 t厨余垃圾、可回收物、餐厨垃圾和低值可回收物,碳排放分别减少5.69、302.58~328.75、83.19、884.66 kg。未来,随着低值可回收物分类和再生资源中心建设的推广,生活垃圾碳排放总量和强度将进一步降低,推动城市绿色低碳发展。

城市生活垃圾固体替代燃料的制备技术及应用

针对城市生活垃圾等固废产生量日益增多、组分复杂,处置时易产生温室气体,对其有效管理和碳减排成为当前关注的热点。介绍了城市生活垃圾处理现状及国内外固体替代燃料标准,叙述机械生物处理技术中包含的生物干化、机械分选技术等工序,分析了固体替代燃料燃烧过程中存在的潜在问题,结合城市生活垃圾常规处理和机械生物处理工艺效果,获得机械生物处理后的固体替代燃料热值达到10536 kJ/kg,比原生垃圾热值提升了3倍,且不需要添加辅助燃料进行燃烧。固体替代燃料在水泥、电力等行业应用能提高资源有效再利用,减少化石燃料的使用,对节约成本、保护环境以及推进我国垃圾分类和碳中和进程具有重要意义。

废弃软质聚氨酯泡沫塑料的碱性水热降解

利用连续水热处理装置,开展了废弃软质聚氨酯泡沫塑料的水热降解研究。比较了碳酸钠、氢氧化钠和氢氧化钾3种碱性助剂对水热处理效果的影响。实验结果表明:3种碱性助剂对废弃软质聚氨酯泡沫塑料的水热降解均表现出一定程度的促进作用,其中氢氧化钾和氢氧化钠的促进作用较强,持续时间较长;增加氢氧化钠或氢氧化钾的用量、升高温度,均能够促进废弃软质聚氨酯泡沫塑料的水热降解;在用量相同的条件下,氢氧化钾的促进作用优于氢氧化钠;压力对废弃软质聚氨酯泡沫塑料的水热降解效果影响不明显;氢氧化钾、氢氧化钠可与废弃软质聚氨酯泡沫塑料降解过程中所产生的CO_(2)反应,使其转化为溶解性较好的碳酸盐而转移至水相,还能够促进废弃软质聚氨酯泡沫塑料中某些功能基团的解离,加快某些有机降解产物的进一步分解,从而加快了废弃软质聚氨酯泡沫塑料的降解过程。