Critical review for the quantification of leachate production: Evaluation example for the “Oum Azza” public landfill in Rabat city,Morocco

The estimation of leachate quantities produced in landfills is necessary to dimension the treatment plants allowing to reduce the polluting load of these effluents and consequently avoid their negative impacts on the environment. Different leachate quantification methods were used in this study to assess the leachate volume produced at the Oum Azza landfill. The water balance method give comparable estimations of leachate production to the Ouled Berjal landfill ratio. The first method showed average values between 487 and 495 m³/day for 2015, 2018, and 2019, and at the same time, the second method gave values between 470 and 477 m³/day for the same years. In contrast, the World Bank ratio showed high values that vary between 2260 and 2295 m³/day for 2015, 2018, and 2019. The on-site data and the statistical analysis showed us that the World Bank ratio is not adapted for the estimation of the leachates produced in Oum Azza landfill, while the water balance and the ratio of Ouled Berjal landfill allowed to give comparable results to reality.     

欧盟包装废物管理和总体产生特性分析

欧盟旱在1994年就颁布了包装和包装废物的指令,提出了包装废物管理的目标和管理内容,要求各成员国采取积极的经济和法律措施,建立自由流通的公平市场秩序。通过研究评估表明,包装和包装废物指令的实施产生了多方面的积极影响。统计数据表明,历年包装废物回收总量平稳增加,处置量平稳下降,单位GDP产值产生包装废物的系数基本保持稳定,但各国包装废物人均产生量存在较大差异。     

污水处理厂中全氟化合物的污染研究

为研究全氟化合物在污水厂中的去除效率和环境行为,对泰安市2座污水处理厂进出水中不同链长的全氟磺酸和全氟羧酸的存在与分布进行了采样调查,并分析了全氟辛烷磺酸(PFOS)和全氟辛烷羧酸(PFOA)在采用曝气-A2O工艺的污水处理厂各单位中的浓度变化情况.研究发现,上述污水厂进出水中全氟化合物的污染程度较轻,其中,PFOA、...     

大豆蛋白粉喷雾干燥塔尾气余热的回收与利用

针对大豆蛋白粉生产过程中喷雾干燥塔尾气温度较高,有回收利用价值的现实,也针对目前的节能需求,对现有的喷雾干燥塔的尾气排放部分进行改造,设计一个片状空气预热器,以利用高温的尾气与系统的进气做热交换,实现热量再利用,降耗和提高蛋白粉产率的目的,并对投资收益进行了分析。     

重庆含铜废物利用行业技术准入研究

因缺失含铜废物利用技术准入规范,从业企业良莠不齐,制约了该行业的良性发展.通过分析重庆市含铜废物利用现状、存在问题,从含铜废物利用项目选址用地、建设规模、产品质量、技术工艺、设施建设、准入许可及环境管理等方面提出准入门槛规定,以期为含铜废物利用行业良性发展提供参考.     

上海市危险废物处理处置及管理对策探讨

简要介绍了国外危险废物管理制度及法律法规体系;表述了我国危险废物的管理法规．制度及控制标准;阐述了上海市危险废物处理处置及管理现状;分析了存在的主要问题;从6个方面提出了上海市危险废物的管理对策。     

一起液氯泄漏事故的分析及预防对策

针对国内近年来氯气泄漏、爆炸事故频发的现状,选择其中具有典型性的江西某厂氯气泄漏事故,运用因果分析方法对其事故原因进行系统分析,根据分析结果,以降低事故发生概率和严重度为目标,从管理角度提出预防对策.     

生活垃圾焚烧厂贮坑沥滤液的负压蒸发预处理研究

采用负压蒸发法处理上海市某大型生活垃圾焚烧发电厂贮坑沥滤液,实验研究了沥滤液蒸发过程中冷凝液组分的变化特征.结果表明:生活垃圾焚烧厂贮坑沥滤液中含有高质量浓度的挥发性污染物,低碳醇和碳原子数不大于7的挥发性有机酸(VFA)约占沥滤液中有机碳质量浓度的50%;沥滤液直接蒸发可将原液转化为原液量的84%,不含氨氮,有机物质量浓度为原液的21%,且90%以上为VFA及低碳醇的冷凝液,以及有机物质量浓度浓缩了4.4倍,适于焚烧处理的浓缩液;通过蒸发处理,沥滤液的处理难度大大降低,蒸发用能可取自焚烧热能回收后的低温位热能,降低了蒸发处理的费用.      

Usage of polystyrene disposable food dishes in the lightweight concrete making

The increasing use and subsequent accumulation of polystyrene containers has triggered a substantial environmental problem. This study investigated using varied percentages of solid waste polystyrene disposable food dishes in the production of lightweight concrete samples with 350 kilograms per cubic meter (kg/m³) of cement and a density of 1,300 kg/m³. The polystyrene disposable dishes were ground into beads of 0–3 millimeters (mm) and 3–6 mm in size. First, the characteristics of Type II Portland cement, polystyrene, and aggregates were examined. The following characteristics of concrete using ASTM International and British Standards Institution standards were tested: slump, compressive strength, ability to resist chloride ion penetration, and resistance of concrete to rapid freezing and thawing cycles. Scanning electron microscopy (SEM) and energy dispersive X‐ray spectroscopy analytical techniques were also used. The slump of samples varied between 40 and 70 mm and was not dependent on either the polystyrene percentage or the size of the polystyrene beads in the concrete samples (p‐value > .05). The compressive strength of the concrete samples after 90 days of curing, and using different percentages of polystyrene, varied between 96 and 113 kilograms per square centimeter (kg/cm²). The resistance of the samples to the freezing and thawing cycle and chloride ion penetration were affected unfavorably by the presence of the polystyrene. The SEM technique indicated that concrete samples containing 15% and 25% polystyrene had denser crystals and less void than concrete samples with 40% and 55% polystyrene.     

Comparison of energy produced from waste by removing its different components: A case study of the waste landfill in Tehran

In developing and populated cities such as Tehran, a massive amount of municipal solid waste (MSW), both wet and dry, is transferred to landfills daily. Combustion is one of the most common methods of using mixed waste energy from the past to the present. The Dulong formula is widely used to calculate the energy released from MSW combustion. According to the constituent components of Tehran MSW, removing food waste leads to an increase in energy potential, which will be a suitable condition for energy production. In this work, the energy derived from the combustion of mixed and separated dry MSW generated in Tehran was calculated using the experimental Dulong formula and tables in Integrated Solid Waste Management (Tchobanoglous et al. 1993, McGraw‐Hill). The Dulong formula indicates that the use of Tehran mixed MSW (without separating materials for recycling) as a fuel source yields 8,966.40 KJ/kg while the use of Tchobanoglous et al. (1993) tables can generate 8,236 kJ/kg. By removing food waste and recyclable materials, the potential of energy production changes to 22,047 kJ/kg using the Dulong formula and 16,207 kJ/kg and the Tchobanoglous et al. (1993) tables. It indicates increase by 1.46 times and 46%, respectively. Regarding the 200‐ton capacity of the Tehran waste incinerator, the Dulong formula indicated generation of 4,409 MJ/day energy, and the Tchobanoglous et al. table presents 3,241 MJ/day. Therefore, considering that Tehran generates more than 4,000 tons of reject waste daily, it can easily be converted to energy rather than landfilled. This can alleviate the problem of buying land and construction of landfills and leachate generation.