Estimation of building-related construction and demolition waste in Shanghai

One methodology is proposed to estimate the quantification and composition of building-related construction and demolition (C&D) waste in a fast developing region like Shanghai, PR China. The varieties of structure types and building waste intensities due to the requirement of progressive building design and structure codes in different decades are considered in this regional C&D waste estimation study. It is concluded that approximately 13.71 million tons of C&D waste was generated in 2012 in Shanghai, of which more than 80% of this C&D waste was concrete, bricks and blocks. Analysis from this study can be applied to facilitate C&D waste governors and researchers the duty of formulating precise policies and specifications. As a matter of fact, at least a half of the enormous amount of C&D waste could be recycled if implementing proper recycling technologies and measures. The appropriate managements would be economically and environmentally beneficial to Shanghai where the per capita per year output of C&D waste has been as high as 842 kg in 2010.     

Analytical methods and environmental processes of nanoplastics

The degradation of plastic debris may result in the generation of nanoplastics (NPs). Their high specific surface area for the sorption of organic pollutions and toxic heavy metals and possible transfer between organisms at different nutrient levels make the study of NPs an urgent priority. However, there is very limited understanding on the occurrence, distribution, abundant, and fate of NPs in the environment, partially due to the lack of suitable techniques for the separation and identification of NPs from complex environmental matrices. In this review, we first overviewed the state-of-the-art methods for the extraction, separation, identification and quantification of NPs in the environment. Some of them have been successfully applied for the field determination of NPs, while some are borrowed from the detection of microplastics or engineered nanomaterials. Then the possible fate and transport of NPs in the environment are thoroughly described. Although great efforts have been made during the recent years, large knowledge gaps still exist, such as the relatively high detection limit of existing method failing to detect ultralow masses of NPs in the environment, and spherical polystyrene NP models failing to represent the various compositions of NPs with different irregular shapes, which needs further investigation.     

新疆D矿田金矿资源定量评价

本文在建立D矿田找矿信息层次模型基础上,确定矿田统计单元划分和地质变量提取的赋值原则,将该矿田划分出466个统计单元,提取25个地质变量并进行二态赋值,而后应用数量化理论Ⅲ。特征分析法及勃尔法等方法,建立了矿田金矿资源定量评价模型,定位预测了45个勘探靶区。     

南方涝渍地区退田还渔的一个实例分析

以江汉平原四湖涝渍地区的一个经围湖造田形成的典型农业微域为研究对象,在对其土壤和作物生长状况进行调查的基础上,探讨了退田还渔的必要性与具体方案。结果表明,对小型湖泊通过围湖造田所形成的农业微域,在人工排水和土地平整不充分的情况下,其地貌和土壤还残留有原有湖泊的影响,处于原湖泊低处的土壤表现出明显的沼泽化和严重潜育化的特征。在该地区种植水稻产量比正常地区减产达16%～26.8%。利用数量化理论Ⅰ确定了该地区适宜退田还渔的具体位置和面积。按照这一方案实施的结果,该地区从1997～2001年的5年中精养鱼塘面积增加9倍,养鱼的效益比种植水稻高5～10倍,还减轻了该地区夏季和冬季的排水压力。     

红外光谱法测定粉尘中游离二氧化硅综述

全面地回顾了国内外红外光谱法测定粉尘中游离二氧化硅的研究成果。系统而重点地介绍了溴化钾压片法、粉尘滤膜样品重沉积和采样滤膜直接测定技术,分析了样品粒度、标准石英物质和矿物干扰物对测定结果的影响及干扰消除方法;还介绍了国外对红外光谱法与Ｘ－射线衍射法进行比较性研究的结果和动态,并得出结论。文章所列参考文献对本领域研究人员和基层检测人员具有很高的参考价值。     

事故树定量分析与安全指标的数学模型的建立

阐述了在该课题研究过程中，提出的一些新概念、新定义和新方法     

Quantifying construction and demolition waste: An analytical review

Quantifying construction and demolition (C&D) waste generation is regarded as a prerequisite for the implementation of successful waste management. In literature, various methods have been employed to quantify the C&D waste generation at both regional and project levels. However, an integrated review that systemically describes and analyses all the existing methods has yet to be conducted. To bridge this research gap, an analytical review is conducted. Fifty-seven papers are retrieved based on a set of rigorous procedures. The characteristics of the selected papers are classified according to the following criteria - waste generation activity, estimation level and quantification methodology. Six categories of existing C&D waste quantification methodologies are identified, including site visit method, waste generation rate method, lifetime analysis method, classification system accumulation method, variables modelling method and other particular methods. A critical comparison of the identified methods is given according to their characteristics and implementation constraints. Moreover, a decision tree is proposed for aiding the selection of the most appropriate quantification method in different scenarios. Based on the analytical review, limitations of previous studies and recommendations of potential future research directions are further suggested.     

Production patterns of packaging waste categories generated at typical Mediterranean residential building worksites

The construction sector is responsible for around 28% of the total waste volume generated in Europe, which exceeds the amount of household waste. This has led to an increase of different research studies focusing on construction waste quantification. However, within the research studies made, packaging waste has been analyzed to a limited extent. This article focuses on the packaging waste stream generated in the construction sector. To this purpose current on-site waste packaging management has been assessed by monitoring ten Mediterranean residential building works. The findings of the experimental data collection revealed that the incentive measures implemented by the construction company to improve on-site waste sorting failed to achieve the intended purpose, showing low segregation ratios. Subsequently, through an analytical study the generation patterns for packaging waste are established, leading to the identification of the prevailing kinds of packaging and the products responsible for their generation. Results indicate that plastic waste generation maintains a constant trend throughout the whole construction process, while cardboard becomes predominant towards the end of the construction works with switches and sockets from the electricity stage. Understanding the production patterns of packaging waste will be beneficial for adapting waste management strategies to the identified patterns for the specific nature of packaging waste within the context of construction worksites.     

Water conservation due to greywater treatment and reuse in urban setting with specific context to developing countries

In India, the per capita water availability is reducing day by day due to rapid growth in population and increasing water demand. Greywater treatment and reuse is one of the feasible options in developing countries like India to overcome this problem. A greywater collection, treatment and reuse system was designed and implemented in an urban household having a water requirement of 165 liter per capita per day (lpcd) and a greywater generation rate of 80 lpcd. An upflow-downflow greywater treatment plant having a screening, sedimentation, filtration and disinfection as major treatment processes was constructed and treated greywater is used for toilet flushing and to irrigate the vegetables in the backyard of the household. Greywater characterisation indicates that COD and BOD are sufficiently reduced during the treatment and there is also substantially reduction in Escherichia coli count. The payback period of this greywater treatment and reuse system is estimated to be 1.6 year.