Zinc removal from synthetic waters using magnetite/graphene oxide composites

The removal of heavy metals from wastewater has become a global challenge, which demands the continuous study of efficient and low-cost treatment alternatives such as adsorption. In this research, the removal of zinc was evaluated using batch adsorption processes with nonconventional materials such as graphene oxide (GO), magnetite (MG), and their composites (GO:MG), formulated with three weight ratios (2:1, 1:1, and 1:2). Graphene was synthesized by the modified Marcano method, using pencil lead graphite as a precursor. MG and the composites were synthesized by chemical coprecipitation of ferrous sulfate and ferric chloride. The materials were characterized by Raman and Fourier transform infrared spectroscopies, scanning electron microscopy, X-ray diffraction, and the Brunauer–Emmett–Teller method to determine the functional groups, microstructural and morphological characteristics, and specific surface area. Batch adsorption tests were carried out to optimize the adsorbent dose and contact time with zinc solutions of 10 ppm. Zinc adsorption reached equilibrium at 2 h, with an optimal dose between 0.25 and 1.0 g/L. The maximum zinc removal efficiencies/adsorption capacities were 98.6%/165.6, 83.4%/47.6, 83.5%/21.9, 72.8%/19.9, and 82.2%/9.25 mg/g using GO, 2GO:1MG, 1GO:1MG, 1GO:2MG, and MG, respectively. Furthermore, the analysis of the isotherm and adsorption kinetics models determined that the adsorption processes using MG and the composites fit the Sips and pseudo-second-order models.     

Analysis of emergency situations at municipal solid waste landfills

Journal of Material Cycles and Waste Management - This work focuses on the issue of emergency prevention in the operation of municipal solid waste landfills. In this work, an emergency is...     

Production of new concrete with leather tannery waste used as partial replacement of the natural sand

Journal of Material Cycles and Waste Management - Leather production is a technology that boosts the economy because of its versatility and durability. However, the wastes generated throughout the...     

Construction and demolition waste management in Kosovo: a survey of challenges and opportunities on the road to circular economy

Managing Construction and demolition waste (CDW) is a severe and growing urban challenge, particularly in post-conflict countries. Though Kosovo has significantly rebuilt and developed after the Liberation War, these initiatives have accompanied suboptimal waste management. This research evaluates CDW management in Kosovo by assessing current practices and operations vis-a-vis the legal framework and EU requirements. It identifies instruments and policies capable of ameliorating gaps and proposes a more sustainable and circular CDW management system for Kosovo. Information was primarily collected during on-site visits to Pristina and the surroundings by a cohort of Urban Management Students from the Technische Universität Berlin, students from Kosovo, and the local office of the Gesellschaft für Internationale Zusammenarbeit, GIZ. The analysis identified gaps in Kosovo's CDW management and its observance and enforcement of existing CDW legislation, including an ambiguous licensing system impeding sustainable demolition, storage, and transport; the absence of approved CDW storage options leading to uncontrolled disposal; and an underdeveloped market for recycling and reuse, deterring stakeholders from further pursuit of circular practices. These gaps were compounded by poor recordkeeping, obscuring precise information on CDW streams. Possible instruments and incentives to support Kosovo's transition to a more sustainable CDW management system were then identified.

     

喀斯特地区非物质文化遗产空间格局及影响因素——以贵州省为例

厘清喀斯特地区非遗分布的空间格局有利于盘点资源现状,客观了解区域文化产生过程,以提高非遗的管理、保护与开发水平.基于地理学空间视角,利用GIS空间分析方法,探讨贵州9个地州市1023项非物质文化遗产类型结构、空间格局及影响因素,研究发现:(1)贵州省非物质文化遗产项目类型结构层次分明,民俗类数量最多,曲艺、传统医药与传统美术类相对稀缺;(2)贵州省非物质文化遗产空间分布不均衡,以贵阳市和黔东南州为双核心,中部和东部集聚明显,西部地区分布较少;(3)贵州省近90％的非物质文化遗产集中分布在海拔1400 m以下的喀斯特低山、中低山区域,曲艺类占比最高,传统体育、游艺与杂技和传统技艺两类分布与主要河流流域拟合较好,民间文学类与明清时期主要交通干线空间分布关联较高;(4)地形地貌、水系、文化、交通、经济等自然和人文因素对喀斯特地区非物质文化遗产空间格局产生重要影响.     

基于复合治理理论的基层应急管理模式优化*

为弥补传统基层应急管理模式的短板,解决信息壁垒、协调困难、公众参与不足等问题。从复合性视角出发,阐述复合治理理论内涵,探讨复合治理与应急管理在主体、思维、过程、空间、目标上的契合性,并进一步分析基层应急管理的现实背景和困境,进而构建基于复合治理理论的基层应急管理模式,阐明模式基本结构和工作流程,最终提出理念树立、平台搭建、机制保障、队伍建设、制度安排、文化营造、技术支撑方面的优化路径。结果表明:复合治理理论的应用可以加强基层应急管理能力,促进多元主体协同共治。     

汽车前风挡玻璃油雾现象分析及管控建议

本文采用FTIR/GCMS/PY-GCMS联合分析手段对某车型前风挡玻璃内侧油雾成分进行了分析,结果表明油雾的主要成分为邻苯二甲酸酯类物质。基于油雾产生的实际工况及油雾产生的基本原理推断,油雾产生的原因为车内环境内SVOC物质挥发并在前风挡玻璃内侧冷凝所致。针对邻苯二甲酸酯类SVOC物质的管控,本文通过对比分析行业内主流的重量法及光泽度法的优缺点,基于车内环保属性及实际应用场景风险管控角度,提出了雾化指标应同时管控重量法及光泽度法的技术建议。     

Rainfall Interception Based on Indirect Methods: A Case Study in Temperate Forests in Oaxaca,Mexico

Rainfall interception represents the amount of water trapped in natural cover that is not drained directly to the ground. Intercepted rainfall may evaporate after a rain event, making it one of the main drivers of water balance and hydrologic regionalization. This process can be affected by factors such as climate, altitude, vegetation type, and topography. Here is a simple method of calculating rainfall interception in temperate forests using in Santa Maria Yavesia, Oaxaca, and Mexico as an illustrative study area. We used two rain gauges to measure net precipitation (N_p) under the canopy at each study site and one gauge outside the canopy to obtain gross precipitation (G_p). Throughfall (T_h) was indirectly measured using hemispherical photographs. Rainfall interception was obtained through a combination T_h and G_p and N_p. The mean rainfall interception was 50.6% in the Abies forests, 23%–40% in the coniferous‐mixed forests, and 27.4% in the broad‐leaved forests. We classified rainfall events by intensity to determine the effect of canopy structure and precipitation and found that 75% of the events were weak events, 24% were moderate events, and 1% were strong events. In addition, we found that rainfall interception was lower when the intensity of precipitation was higher. Our method can be replicated in different ecosystems worldwide as a tool for assessing the influence of rainfall interception in terms of ecological services.     

山东省农田土壤中拟除虫菊酯类农药污染特征与风险评价

在山东省范围内采集农田表层土壤样品91个,采用气相色谱法分析了7种拟除虫菊酯类农药(SPs)的含量和组成,分析了其分布特征,比较了大田土壤和大棚土壤中该类农药含量的差异,并评价了其生态风险.结果表明,7种拟除虫菊酯类农药总含量(∑_7SPs)范围在0.01—88.51μg·kg~(-1)之间,均值为5.65μg·kg~(-1).与国内其他地区农田土壤相比,山东省农田土壤中拟除虫菊酯含量处于中等偏低水平.山东省各地区的拟除虫菊酯含量存在差异,但组成相近,均是高效氯氟氰菊酯、联苯菊酯和氯氰菊酯的比例较高.部分地区大棚土壤中的含量高于大田土壤.风险评价结果表明,山东省农田土壤个别采样点中甲氰菊酯和高效氯氟氰菊酯具有生态风险,三分之一的采样点存在潜在生态风险,其余采样点不存在生态风险.