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.     

Spatial and Seasonal Response of Municipal Water Use to Weather across the Contiguous U.S.

Weather variability has the potential to influence municipal water use, particularly in dry regions such as the western United States (U.S.). Outdoor water use can account for more than half of annual household water use and may be particularly responsive to weather, but little is known about how the expected magnitude of these responses varies across the U.S. This nationwide study identified the response of municipal water use to monthly weather (i.e., temperature, precipitation, evapotranspiration [ET]) using monthly water deliveries for 229 cities in the contiguous U.S. Using city‐specific multiple regression and region‐specific models with city fixed effects, we investigated what portion of the variability in municipal water use was explained by weather across cities, and also estimated responses to weather across seasons and climate regions. Our findings indicated municipal water use was generally well‐explained by weather, with median adjusted R² ranging from 63% to 95% across climate regions. Weather was more predictive of water use in dry climates compared to wet, and temperature had more explanatory power than precipitation or ET. In response to a 1°C increase in monthly maximum temperature, municipal water use was shown to increase by 3.2% and 3.9% in dry cities in winter and summer, respectively, with smaller changes in wet cities. Quantifying these responses allows urban water managers to plan for weather‐driven variability in water use.     

电动技术去除城市污泥重金属的试验研究

采用直流电解污泥反应器,在20V稳定电压作用下进行试验,通过采用蒸馏水和添加电解质的蒸馏水为电极液的两套反应器进行对比试验,测定电动过程中污泥工作区pH值、电压降分布和重金属浓度变化情况,研究电动去除城市污泥中重金属过程中不同污泥工作区的污泥性质的变化及重金属去除效果,并确定了能有效去除污泥中高浓度重金属的有效电动工作区。     

上海城市生活垃圾处置现状及发展方向

分析上海生活垃圾的特点和处理处置现状,对处理处置现状存在的问题进行了分析说明。分类收集要实行日常化,无害化处理水平有待提高,焚烧造成了严重的二次污染,要加强对渗滤液的处置,并且末端处置技术中填埋处置比例过高。同时提出了生活垃圾处置的技术路线和发展方向,要以无害化、减量化、资源化为处理目标。要求巩固和完善生活垃圾卫生填埋技术,谨慎发展生活垃圾焚烧技术,充分重视生活垃圾生化处理技术,多元并举走可持续发展之路。     

生活垃圾焚烧厂沥滤液处理技术研究进展

生活垃圾焚烧厂沥滤液污染物浓度高,水质成分复杂,是我国污水处理领域的热点和难点之一。重点介绍了生物处理技术、膜技术、物化处理技术、蒸发处理技术及其组合工艺用于垃圾焚烧厂沥滤液处理的研究进展,对现存的问题进行了分析并提出了相应的建议。     

城市再生水景观利用水华识别和预警方法探讨

城市再生水景观回用的主要问题是水体富营养化导致水华的暴发。为了抑制藻类的大规模生长,需要提前采取预防措施,以便将有可能爆发水华的藻类及时杀死或除去。目前,人们已经对景观水体中常见藻类的生长规律做了深入的研究,发现水体中藻数量(藻密度)的多少与水体的pH值和DO值的变化有密切而相对稳定的关系。通过在线实时监控pH值和DO值,找到△pH、△DO与藻类生长之间的关系,并结合pH、DO、温度、正磷酸盐和总氮等指标,实现实时识别和预测水华爆发的目的。     

垃圾焚烧灰性质分析及控制方法

随着焚烧技术在垃圾处理方式中普遍采用,焚烧产生的灰渣数量也日益增加。灰渣与飞灰中有毒的重金属及有机物质会污染土壤与地下水,对人类健康造成极大的影响。本文对各类垃圾焚烧灰渣的物理化学性质及重金属浸出特性进行了详细的阐述,介绍了灰渣的毒性分析与控制方法。通过分析可知:为了避免灰渣二次污染应该重点控制铬、镉、铍、铅等重金属和二恶英、呋喃等有机物的污染;处置后的灰渣有害离子浸出能力降低,根据灰渣物理和工程性质,可以成为再生资源充当填充材料和混凝土与沥青路面骨料等。     

硫磺/石灰石自养反硝化系统脱氮除磷性能研究

为了考察硫磺/石灰石系统对于低C/N的城市污水进行同步脱氮除磷的性能,设计了体积比为1∶1的硫磺/石灰石柱式反应器,以人工配水为处理对象,采用厌氧生物滤池运行方式,研究了HRT、初始磷浓度、pH、温度等因素对其脱氮除磷性能的影响.结果表明,在进水NO 3^--N为30 mg/L左右,PO4^3--P为15 mg/L条件...     

分类收集蔬菜垃圾与植物废弃物混合堆肥工艺实例研究

以分类收集的生活垃圾(主要为蔬菜垃圾)和破碎树枝为原料,采用条垛式堆肥工艺,在中试规模条件下考察了原料初始含水率、通风频率、翻堆频率、接种比例4种因素对混合堆肥效果的影响.同时,在试验的9种工况下,对温度、氧浓度、有机碳降解率、有机碳氮比(C/N)、腐殖质含量等指标进行测定.结果表明,堆肥42d时各堆体均已达到稳定化要求.经过比较肥分保持、腐殖化程度和能量投入等指标,获得的最优堆肥控制条件为:初始含水率65%,通风频率15min/60min(开/关),翻堆频率为每3d1次,产物接种比例5%.最优控制方案下的主发酵通风率仅为0.03L.min-1.kg-1(以VS计),可实现堆肥过程的低能耗,适合于我国村镇区域的应用条件.     

组合人工湿地对城镇污水处理厂尾水中有机物的去除特征研究

采用物理分级和三维荧光光谱法,研究了组合人工湿地对城镇污水处理厂尾水中不同形态有机物的去除特征.结果表明,组合人工湿地对污水处理厂尾水具有较好的深度处理效果,出水水质基本可以达到国家地表水环境质量标准(GB38382-2002)Ⅲ或Ⅳ类水标准.组合人工湿地处理系统对尾水中CODCr和BOD5总体去除率分别达到35.2%和44.3%,对尾水中总有机碳(TOC)、溶解性有机碳(DOC)、颗粒有机碳(POC)的平均去除率分别为46.9%、45.9%、48.3%.组合人工湿地系统不同单元对尾水中有机物的去除贡献率存在差异,其中,潜流湿地单元对尾水中CODCr和BOD5及其不同组分有机碳的去除效率较高.试验期间,由于藻类滋生,表流湿地单元出水中有机物含量波动较大,去除效果明显降低,藻类被打捞后,出水水质明显改善.三维荧光光谱分析结果显示,各个处理单元取样点的水样三维荧光光谱均出现4个明显的荧光峰.人工湿地各单元出水溶解性有机质(DOM)中,类蛋白和类腐殖酸物质含量较高,类富里酸物质含量较低.人工湿地对类蛋白和类腐殖酸物质有较强的去除作用.