International Journal of Sustainable Built Environment最新文献

The temperatures of sewage water were too low in cold climatic regions of Baltic Sea, which resulted in inefficiency of denitrification in sewage treatment process (STP). This is not prescribed to meet the effluent nitrogen levels (<10 mg/l) as per Urban Wastewater Treatment Directive 98/15/EC. In order to improve the denitrification efficiency and the subsequent removal of nitrogen from the municipal wastewater as per the above European Commission guidelines, modified process was formulated with pre-anaerobic and post-aerobic activated sewage treatment processes. The modified process includes the rise in ambient temperature up to 20 ± 2 °C by using heat exchangers in Increased Technology and Efficiency in Sewage Treatment (ITEST) pilot plant at the Swedish Environmental Research Institute (IVL) laboratory. The experiments were conducted with the modified process of sewage water in one line (treatment line (TL)) and the existing process in another line (reference line (RL)) of the pilot plant. The physical (such as Temperature, Suspended solids and Sludge volume) and chemical (ammonium-nitrate (NH₄⁺-N), nitrate-nitrogen (NO₃⁻-N) and total-nitrogen (TN)) parameters were analyzed. The results concluded that the NH₄⁺-N, NO₃⁻-N and TN concentrations of treated waste water were satisfactory with a concentration of <10 mg/l as per the European Directives 98/15/EEC at treatment line as compared to influent and reference lines. The average nitrogenous-compounds’ removal efficiencies were 84% and 76% of NH₄⁺, 80% and 65% of NO₃⁻, 78% and 62% of TN for TL and RL, respectively.

High temperatures in urban areas affect the health and wellbeing of urban dwellers. Malacca City has undergone a tremendous growth during the last decades, particularly after its designation as a UNESCO World Heritage Site in 2008. As a result of urban development, two dominant urban configurations were formed in Malacca: the heritage site and contemporary urban areas. This study examines the effects of aspect ratio (H/W) on air temperature in two urban configurations in Malacca. The three-dimensional microclimatic modelling system ENVI-met (version 3.1) was used to simulate the summer time air temperature variation in the typical urban setting of a heritage site and contemporary urban area. Aspect ratio was found to have a considerable influence on the air temperature distribution in both areas. The daytime air temperatures decreased with increasing aspect ratio. The simulation results showed that during the daytime, the heritage site (aspect ratio of 2.6) was warmer than the contemporary urban area (average value of H/W = 1.6), and that cooling occurred more quickly in the latter. The results of this study provide useful information for planning, building and modifying urban structures.

This paper presents the effect of silica fume (SF) on early-age and long-term mechanical properties of recycled aggregate concrete containing slag. In this study six series of mixes are considered. The first series is control concrete containing 100% ordinary Portland cement (OPC) and 100% natural aggregates. The second series is similar to the first series in every aspect except the natural coarse aggregate (NCA) which was partially replaced by 50% (by wt.) recycled coarse aggregate (RCA). The third series is also similar to the second series except the OPC which is partially replaced by 50% slag. The effects of 5, 10 and 15% (by wt.) SF on mechanical properties of concrete is evaluated in fourth, fifth and sixth series, respectively. Compressive strength, indirect tensile strength and modulus of elasticity of above concretes are measured at 3, 7, 28, 56 and 91 days. Results show that the addition of 50% slag significantly reduced the above mechanical properties of concrete containing 50% RCA at early age. Among three SF contents, the 10% SF improved the above mechanical properties of recycled aggregate concrete containing slag at early ages (3 and 7 days) as well as at 28 days. The addition of 10% SF also improved the 56 and 91 days compressive and tensile strengths of recycled aggregate concrete containing slag. It is also found that the long-term (56 and 91 days) compressive and tensile strengths of recycled aggregate concrete containing slag and 10% SF are even higher than the OPC concrete containing 50% RCA and control concrete, respectively. It is also observed that the slow pozzolanic reaction of slag contributed to the long-term compressive and tensile strengths of recycled aggregate concrete containing slag and 10% SF. Strong correlations of measured compressive strength with indirect tensile strength and elastic modulus of above environmentally friendly concretes are also established.

This study explores the sense of place in the small coastal Algerian town of Tipaza. The town is famous for its world archaeological sites, but its inhabitants and the local community in general seem to appreciate more its exceptional landscape than the universal archaeological values conferred to it by UNESCO. The particular townscape clearly delimited by the Mediterranean Sea and the Chenoua Mountain seems to have strongly influenced people’s mental images and attachments to their town. Based on the concepts of environmental representation and place attachment, local-community’s sense of place is investigated at three territorial scales: the town centre, the town as a whole and the region. Since the sense of place is defined as a multidimensional attitude including cognitive, conative and affective aspects, the proposed paper examines the socio-cognitive dimension through the structural approach of social representations where shared socio-cognitive meanings are assumed to constitute the central core of environmental representations. On the other hand, the conative component has been investigated through the analysis of expected activities in favourite places. Moreover, place attachment, an affective bond between people and environmental setting, is explored through two sub-concepts: place identity which refers to the cognitive level and place dependence which refers to the conative level. By exploring shared local community’s meanings and their impact on place preferences and appropriation, the research aims at showing the value of townscapes and particularly coastal ones in urban development projects. Natural features such as the sea are powerful landmarks and have strong impact on people’s perceptions of environmental settings.

Evidence continues to emerge that green-labelled buildings achieve a higher financial return than conventional buildings, both in terms of rent and sale price (referred to as the green premium in the literature). Consequently, the green premium is considered as a potential driver of investment in labelled buildings. However, it is not clear to what extent investors’ expectation of a green premium can help to stimulate the development of green buildings in the developing countries. This study, therefore, assesses the available evidence, as well as trends of property development in the UK and US, as countries with significant concentrations of green-labelled office buildings. The study raises issues that should be considered in adopting the existing empirical findings and presents recommendations for the development of a viable green property market in developing countries.

This study specifically looked at total water supply in China, water withdrawal from various sources and various usage of water. From the analysis, it was realized that water supply from the underground source contributes greatly to the total water supply in China, a cubic unit withdrawal in underground water results in about 45% increase in the total water supply. Water from other sources also contributes to the total water supply in China. Water from other sources includes supplies from wastewater treatment, rain collection, seawater desalinization and other water projects. The result shows that a cubic unit increase in withdrawals from other sources results in about 3% change in gross water supply in China. A cubic unit withdrawal of water for industrial use results in about 29% increase in water use in China. For the agriculture sector, the result shows that a cubic unit increase in agriculture usage leads to approximately 67% increase in total water use in China. Water for household consumption, saw a 15% increase in total water usage in China for every cubic unit withdrawal.