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TiO2_Pd prepared by the incipient wet impregnation (IWI) method was successfully used as a photocatalyst for the degradation of an emerging water pollutant, clofibric acid (CA). It exhibits an improved photoactivity in comparison with different commercial titania in the degradation of CA (25 ppm). The irradiation intensity, photocatalyst dose, CA concentration and influence of water quality and of some salts in the reaction medium were systematically examined to understand their effects on the process efficiency. A total pollutant decomposition and a high mineralization yield (78%) were achieved in 50 and 190 min, respectively, in the optimal conditions, which is very promising for practical applications. [ABSTRACT FROM AUTHOR]

The objective of this article is to develop a set of guidelines that allow to improve the planning of the demolition activities and to promote more sustainable practices in the construction site. The empirical research was carried out by the application of three case studies, developing a diagnosis of the operation of the activities of the companies practicing the selective demolition in small buildings, through interviews, monitoring the demolitions and the resale of the materials. Thus, it was possible to verify the existence of markets for recycled materials and components that promote local development. [ABSTRACT FROM AUTHOR]

This research lies within the framework of identifying and validating practical and cost-effective solutions that would contribute to reusing millions of tons of granular materials from abrasives spread every year in Québec to ensure transportation safety in winter. The behavior of abrasives shows degradation of their inherent properties, essentially due to a transformation of their grading range that shrinks, resulting mainly from compressive stresses between the passing of traffic and the pavement. Nonetheless, they keep their mechanical properties classifying them in category 1 fines in the NQ 2560-11/2002 standard of the 'Bureau de normalisation du Québec' in 2002. The results of physical characterization tests show a number of re-use possibilities in line with current laws, standards and regulations in Québec. An application in asphalt mixes is successfully tested. [ABSTRACT FROM AUTHOR]

In order to meet the ever-growing human needs, the development of new materials implies generation of byproducts or residues that might pollute the environment. This has been a fact not only in massive commercial production but also at pilot-plant and laboratory scale. In today’s world the issue of residues not only cannot be neglected anymore but should also constitute a key requirement for any new research or technology proposal. Consequently, sustainability, reutilisation and recycling aspects should be considered from the outset as equal factors. This can be achieved systematically and methodologically through ‘the modified central paradigm of materials science and engineering’, described previously by the authors as ‘processing → structure → property → performance → reutilisation/recyclability’ and presented here through a new graphical model. This modified central paradigm is equally valid during the extraction and production of a given material for the first time as well as during its reutilisation/recycling. [ABSTRACT FROM PUBLISHER]

Abstract: Circular economy (CE), with its basic principle of Reduce, Reuse, and Recycle, has been determined as the key strategy for the national development plan by the Chinese government. Given the economy-wide material flow analysis (EW-MFA) that leaves the inner flow of resource reutilisation unidentified, the reutilisation-extended EW-MFA is first introduced to evaluate and analyse the material input, solid waste generation, and reutilisation simultaneously. The total amount of comprehensive reutilisation (CR) is divided into three sub-flows, namely, reutilisation, recycle, and reuse. Thus, this model is used to investigate the resource CR in China from 2000 to 2010. China’s total amount of CR and its sub-flows, as well as the CR rate, remain to have a general upward trend. By the year 2010, about 60% of the overall solid waste generation had already been reutilised, and more than 20% of the total resource requirement was reutilised resource. Moreover, the growth patterns of the CR sub flows show different characteristics. Interpretations of resource reutilisation-related laws and regulations of CE and the corresponding policy suggestions are proposed based on the results. [Copyright &y& Elsevier]

Abstract: The aim of the present study was to produce biodiesel from mixtures of cooking oil and provide a possible environmental solution for the region of Campinas (state of São Paulo, Brazil) based on the theory of environmental cost accounting (ECA). Cooking oil collected from homes in Campinas was mixed with ethanol at a ratio of 7:1 and transesterified at 60 °C for one hour for the obtainment of biodiesel using NaOH as a catalyst. The results of the physicochemical analyses demonstrated that the biodiesel possessed characteristics close to those required by Brazilian standards. A recent survey carried out in the city of Campinas revealed that residents are not concerned with the increased of environmental impact and ecological costs in the region caused by the disposal of used cooking oil, which is discarded in sewers and soil. Urgent action is recommended, beginning with raising awareness among the population and the implementation of a policy to determine the storage, periodic collection and use of cooking oil for the production of biodiesel. This fuel could be used for buses, trucks and machines or sold to fuel distributors, offering a savings of US$ 0.8 to 4.5 millions. Campinas could then gain environmental credits and become a sustainable city. Moreover, used cooking oil constitutes low-cost biodiesel with no consumption of raw materials and will reduce worldwide criticism directed at Brazil regarding the use of oleaginous plants for biodiesel production. [Copyright &y& Elsevier]

Upgradability is often examined as a life-cycle characteristic that reflects the capability of a product for accommodating functional improvements to achieve a competitive reutilisation and service life extension. As with many life-cycle characteristics, the upgradability of a product is strongly influenced by the configurations of functional, physical, as well as structural features, which are determined at the design stage. In this paper, an optimisation approach is presented to facilitate the search for the optimal design solution for a product's upgradability. The implementation of such an approach is based on a Product Upgradability Index (PUI) model and aims to maximise the Upgradability Efficiency (UE) of a design within specified engineering, economic, and environmental constraints. Genetic algorithm (GA) techniques are used to enable the global search mechanism of the optimisation approach. By using GA, the approach is formulated with three major schemes, namely the fitness evaluation, solution encoding, and genetic operation schemes. [ABSTRACT FROM AUTHOR]

Since 2007, some supermarkets in Portugal have voluntarily abolished the free distribution of plastic bags, implementing a symbolic charge of €0.02 each at the same time that others still offer free plastic bags. This study assesses the influence of this voluntary measure on the reduction of plastic bags consumption, comparing clients from supermarkets that have adopted it with others who have free distribution. The reutilisation of bags reached 37% in supermarkets where customers pay a fee and was absent in supermarkets where plastic bags are free. Even the abstention of using bags, when clients buy only few products, is significantly higher in supermarkets where there are charges for plastic bags. The 2 cents charged has also induced a significant increase in optimal use of plastic bags since 52% of clients that pay for plastic bags use them so they are almost full, but only 17% do the same when they are free. Taken together, the different effects of charging for plastic bags represents a potential reduction of 64%. A mandatory tax on plastic bags is an important measure to reduce substantially the number of plastic bags consumed and to improve sustainability through the reduction of environmental, economic and social costs of pollution and waste management. [ABSTRACT FROM AUTHOR]

A low sludge discharge membrane bioreactor (LSDMBR) for greywater reclamation was developed and tested in this study. LSDMBR was designed by combining an aerobic activated sludge process with an immersed membrane filtration process. LSDMBR offers the following advantages over conventional activated sludge processes. Firstly, LSDMBR has a high biomass concentration attributed to membrane filtration of the effluent and low sludge wasting, which results in reduced disposal costs. Secondly, LSDMBR provides for a favorable environment for nitrifying bacteria and the promotion of their growth. Finally, LSDMBR provides for higher treatment efficiencies and produces higher-quality effluent for reuse over conventional processes. It was found from laboratory testing that the contaminant removal efficiencies achieved by LSDMBR within 2.5 h of hydraulic retention time (HRT) were as follows: 95% removal of anionic surfactants and 90% removal of 5-day biochemical oxygen demand (BOD5), respectively. It was also found that the effluent ammonia and total Kjeldahl nitrogen (TKN) concentrations were reduced to less than 1 mg/L and 6 mg/L, respectively. Results of the study suggested that LSDMBR is a small-scale and self-sustaining greywater reclamation system that requires low installation space and low sludge discharge. Un bioréacteur à membrane à faible décharge de boues (LSDMBR) pour le traitement des eaux grises a été développé et mis à l’épreuve lors de cette étude. Le LSDMBR a été conçu en combinant un procédé aérobie de boues activées et un procédé de filtration sur membrane submergée. Le LSDMBR offre les avantages suivants par rapport aux procédés conventionnels de boues activées. Premièrement, le LSDMBR possède une forte concentration de biomasse en raison de la filtration sur membrane de l’effluent et du faible gaspillage des boues, ce qui engendre des coûts moindres d’élimination. Deuxièmement, le LSDMBR offre un environnement favorable aux bactéries nitrifiantes et facilite leur croissance. Finalement, le LSDMBR fournit des efficacités de traitement supérieures et produit un effluent réutilisable de plus grande qualité que celle de l’effluent produit par les procédés conventionnels. Les essais en laboratoire ont montré que les efficacités d’élimination des contaminants atteintes par le LSDMBR en un temps de rétention hydraulique (HRT) de 2,5 heures étaient les suivantes : élimination de 95 % des surfactants anioniques, élimination de 90 % de la demande biochimique en oxygène en 5 jours (DBO5). L’étude a découvert également que les concentrations de l’effluent en ammoniaque et en azote total Kjeldahl (TKN) ont été réduites à moins de 1 mg/L et 6 mg/L respectivement. Selon les résultats de l’étude, le LSDMBR est un système de traitement des eaux grises à petite échelle et autosuffisant qui demande peu d’espace et décharge peu de boues. [ABSTRACT FROM AUTHOR]

Acid orange 7 (AO7) is a monoazo acid dye currently used in paper and textile industries. The modelling and optimisation of AO7 adsorption to spent brewery grains (SBG), a by-product of the brewing process, was performed using response surface methodology (RSM). SBG was used dried or previously acid hydrolysed. Five central composite rotatable designs (CCRD), as a function of two variables, each, were followed, namely: (1) amount of SBG and hydrolysis time of SBG; (2) hydrolysis and adsorption times; (3) amount of SBG and adsorption time (T); (4) T and pH medium and (5) T and AO7 concentration.Hydrolysis of SBG showed not significantly increase its adsorption capacity for AO7 dye. Tri-dimensional response surfaces were fitted to the experimental data concerning the removal of dye obtained in CCRD-3 to CCRD-5. From CCRD-3, the best adsorption conditions (96% removal) were estimated for 5.1% (m/v) of SBG after 36 min contact. From CCRD-4, removals above 90% were observed for lower pH values and adsorption times higher than 30 min. An increase in AO7 adsorbed per unit weight of SBG was observed with increasing initial AO7 concentration.Also, SBG was reused in 12 consecutive batches, under previously optimised conditions. SBG residual adsorption activity can be well described by a first-order decay model. A maximum amount of adsorbed AO7 of 29 mg/g SBG is predicted from the cumulative curve. [Copyright &y& Elsevier]