Prevailing construction and demolition waste management practices : a China study

The construction industry is regarded as one of the largest generators of solid waste in the world. These large amounts of construction and demolition waste generated by continuous construction activities have harmful effects on the environment. China is the largest producer of construction and demolition waste, with an annual generation of 2.4 billion tonnes. Moreover, with the continued development of their construction industry, the total volume of construction and demolition waste generated in China is forecasted to reach 3.96 billion tonnes by 2020. However, without proper management, a significant amount of construction and demolition waste has inevitably occupied land resources. In the current age of enhanced environmental awareness, transformation to sustainable management in the construction sector is needed. Despite the increasing awareness of recycling in industry, the average recovery rate of construction and demolition waste in China is only approximately 5%. Few developed countries have a sustainable society with an orderly, reasonable, and effective construction and demolition waste management system. However, as most of the waste in China is directly dumped or landfilled, it lags far behind these high-performance countries. The objectives of this study were to obtain information about the current status of construction and demolition waste management in China from comparative analyses and case studies, and to identify the obstacles to the promotion of recycling. Recovery rates of construction and demolition waste were collected from 35 countries, and the existing policies, standards, and official documents at a national level in China and seven selected countries with high performance (including Japan, South Korea, Germany, Austria, the Netherlands, Italy, and the United Kingdom) were reviewed. The comparative analysis revealed the reasons for China’s unsatisfactory performance. These reasons included the following: (1) inadequate guidance on recycling, (2) an underdeveloped recycling market, (3) incomplete knowledge of stakeholders’ responsibilities, (4) ineffective cooperation among governing bodies, (5) a lack of penalty for other stakeholders, and (6) an ineffective supervision system. Few studies have been performed to evaluate construction and demolition waste management performance of different Chinese cities, although case studies have been performed on specific cities. In the present study, site visits to 10 different Chinese cities were conducted: Shanghai (Direct-administered municipalities), Hangzhou (Zhejiang Province), Suzhou (Jiangsu Province), Chongqing (Direct-administered municipalities), Chengdu (Sichuan Province), Xi’an (Shaanxi Province), Changsha (Hunan Province), Shenzhen (Guangdong Province), Nanjing (Jiangsu Province), and Zhoukou (Henan Province). Construction and demolition waste management performance, as well as the obstacles for waste management, varies among these Chinese cities. These obstacles included the following: (1) a lack of sources of construction and demolition waste, (2) a lack of guidance on the application of building materials recycled from waste, (3) a lack of land use for fixed industries, (4) a lack of precise estimations of the waste amount and distribution, (5) a lack of guidance on the classification of construction and demolition waste, (6) unrestrictive landfilling, (7) inconsistent cooperation among different official governments, (8) inadequate research on the use of recycled products and waste separation, and (9) an incomplete waste traceability system. If these obstacles are more fully understood, recommendations can be provided to enhance construction and demolition waste management in China. Policymakers in China can consider the following suggestions: (1) ensuring the stability of construction and demolition waste sources; (2) precise estimation of waste generation and distribution; (3) an effective waste tracing system; (4) improvements in related technology; (5) expanding financial incentives; (6) prioritising the recycling of waste and promoting waste reduction; (7) completion of waste classification and relevant standards; (8) strict landfill bans; (9) consistent cooperation among governmental departments; and (10) expansion of the recycling market

Evaluation of workplace safety performance in the Chinese petroleum industry

Reform of the Chinese petroleum industry has entered its second phase since early 1999. The productivity of the petroleum industry has been greatly improved, while the safety performance and records are not satisfactory. This paper investigates the critical factors for improving safety performance in the Chinese petroleum industry. The data used for the analysis are from a questionnaire survey administered to 480 professionals in the petroleum industry in which 143 valid responses were received. Statistical analysis techniques are used to analyze the data collected. The findings revealed that the most significant source of the safety problem is due to the combination of several reasons, including (a) violation on operating procedures, (b) obsolete facilities and equipment failures, (c) insufficient safety management system, (d) improper commands, number of casualties, and (e) production performances and operating skills. The three most essential protective methods include safety training and increasing staff's safety consciousness, cultivating safety culture, and enhancing equipment management and detecting hazards in time

Review on green building rating tools worldwide : recommendations for Australia

Buildings could be led to adverse impacts on environment, such as generation of construction and demolition waste, and emission of greenhouse gases (GHG). Therefore, promotion on development of green buildings is in need. With the increasing awareness in sustainable development, various rating tools are promoted to evaluate the performance of green buildings. Nowadays, these tools function as a guideline for green building development. There are various green building rating tools developed worldwide, and various countries follow different rules, incentives and regulations. However, despite of promotion of green building rating tools, environmental issues from buildings are still significant in Australia. This research compared green building rating tools in Australia and other countries or regions around the world. This research found that rating tools in Australia lack of (1) mandatory criteria and (2) regulations and incentives. This paper recommended that governmental incentives should be promoted

Comparative analysis on international construction and demolition waste management policies and laws for policy makers in China

In the current age of enhanced environmental awareness, transformation to sustainable management in the construction sector is needed. China currently produces the largest amount of construction and demolition (C&D) waste around the world, but the average recovery rate of the waste was only about 5% in 2017. In order to investigate problems in current C&D waste management in China, a cross-national comparative analysis is conducted among China and seven selected countries (Japan, South Korea, Germany, Italy, Austria, the Netherlands and the United Kingdom), to compare legal texts of national policies and laws which relate to C&D waste management and are currently being used. Through the comparison, problems in management of C&D waste in China are investigated. The problems could be concluded to: (a) inadequate guidance on recycling, (b) lack of market incentives in utilising recycled materials, (c) incomplete knowledge of stakeholders’ responsibilities, (d) lack of penalty for other stakeholders, and (e) inefficient supervision system. By understanding these problems, this paper further provides recommendations to enhance the performance of C&D waste management in China

A Nickel-Containing Polyoxomolybdate as an Efficient Antibacterial Agent for Water Treatment

In view of the water pollution issues caused by pathogenic microorganisms and harmful organic contaminants, nontoxic, environmentally friendly, and efficient antimicrobial agents are urgently required. Herein, a nickel-based Keggin polyoxomolybdate [Ni(L)(HL)]2H[PMo12O40] 4H2O (1, HL = 2-acetylpyrazine thiosemicarbazone) was prepared via a facile hydrothermal method and successfully characterized. Compound 1 exhibited high stability in a wide range of pH values from 4 to 10. 1 demonstrated significant antibacterial activity, with minimum inhibitory concentration (MIC) values in the range of 0.0019–0.2400 µg/mL against four types of bacteria, including Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Escherichia coli (E. coli), and Agrobacterium tumefaciens (A. tumefaciens). Further time-kill studies indicated that 1 killed almost all (99.9%) of E. coli and S. aureus. Meanwhile, the possible antibacterial mechanism was explored, and the results indicate that the antibacterial properties of 1 originate from the synergistic effect between [Ni(L)(HL)]+ and [PMo12O40]3−. In addition, 1 presented effective adsorption of basic fuchsin (BF) dyes. The kinetic data fitted a pseudo-second-order kinetic model well, and the maximum adsorption efficiency for the BF dyes (29.81 mg/g) was determined by the data fit of the Freundlich isotherm model. The results show that BF adsorption was dominated by both chemical adsorption and multilayer adsorption. This work provides evidence that 1 has potential to effectively remove dyes and pathogenic bacteria from wastewater

Evaluation of workplace safety performance in the Chinese petroleum industry

Reform of the Chinese petroleum industry has entered its second phase since early 1999. The productivity of the petroleum industry has been greatly improved, while the safety performance and records are not satisfactory. This paper investigates the critical factors for improving safety performance in the Chinese petroleum industry. The data used for the analysis are from a questionnaire survey administered to 480 professionals in the petroleum industry in which 143 valid responses were received. Statistical analysis techniques are used to analyze the data collected. The findings revealed that the most significant source of the safety problem is due to the combination of several reasons, including (a) violation on operating procedures, (b) obsolete facilities and equipment failures, (c) insufficient safety management system, (d) improper commands, number of casualties, and (e) production performances and operating skills. The three most essential protective methods include safety training and increasing staff’s safety consciousness, cultivating safety culture, and enhancing equipment management and detecting hazards in time

[In Press] Risk assessment of retirement village public-private partnership homes

This study aims to identify and evaluate the potential risks associated with the development of retirement village through public-private partnership (PPP) approach. An international questionnaire survey was conducted with experienced practitioners. The findings show that five risk factors are very significant in the development of retirement village PPPs; these are “inexperience of private partner/developer,” “high operational and maintenance cost,” “inappropriate location of land for project,” “lack of highly skilled operational staff,” and “poor communication among stakeholders”. The results will inform developers and government agencies of the potential risk factors they should consider when engaging in future retirement village PPP arrangements

Critical success factors for developing construction and demolition waste management in China

In recent years, rapid urbanisation has caused a large volume of construction and demolition waste in China. Although China has introduced some documents and policies to manage the waste, these documents are not operable or detailed enough to guide the practice further. It is of great importance to analyse critical success factors (CSFs) that could contribute to the successful development of construction and demolition waste management in China. A survey questionnaire was delivered to 150 participants, with 121 responses returned. Eighteen CSFs were identified and evaluated. The results showed that five factors-namely, 'polluter-pays principle', 'subsidies for recycling activities', 'waste minimisation at the planning stage', 'value-added tax deduction' and 'penalties on violations'-were considered the most important factors. Additionally, differences among the perspectives of three groups of related stakeholders (researchers, industry practitioners and government officers) on the criticality of the 18 CSFs were investigated. 'City plan for land use' was considered to have significant disagreement among researchers and government officers. However, the perceptions of industry practitioners were significantly different from those of researchers and government officers. The disagreements might be caused by the different interests, needs and objectives of related stakeholders. The findings of this study will likely prompt the policymakers in China to consider relevant CSFs to enhance the performance of construction and demolition waste management

First-principles Investigations of Magnetic Semiconductors: An example of Transition Metal Decorated Two-dimensional SnS Monolayer

The absence of magnetic moments in pristine two-dimensional (2D) semiconducting materials has attracted many research interests. Transition-metal (TM) decoration has been found to be an effective strategy to introduce magnetic moments in non-magnetic 2D semiconductors. However, the stability of TM atoms modified 2D semiconductors has not been well explored. Here, taking 2D Tin (II) sulfide (SnS) monolayer as a prototype, we explored the stability of magnetic semiconductors through this method. In our studies, all possible configurations of TM decoration have been considered, namely, adsorption on the intact surface, S vacancy, and Sn vacancy. Based on the energy gain and electronic analysis, our results revealed that most of the TM atoms will form a cluster, and only several TM atoms can be effectively doped into the SnS monolayer. Furthermore, the band calculations showed that only Mn substitution will give rise to a magnetic semiconductor. Thus, the reported results here provide some hidden information for further realization of the magnetic semiconductors and serve as a paradigm to prepare 2D magnetic semiconductors

Effective strategies for developing retirement village public - private partnership

Purpose – The growth in ageing population globally has led to the increase in demand for retirement or aged care homes. Adopting public–private partnership (PPP) in the global retirement village market has become the new approach to address some of the emerging challenges. This paper aims to explore and analyse the critical success factors (CSFs) for the adoption of PPP in the global retirement village market. Design/methodology/approach – An empirical questionnaire survey was conducted with experienced practitioners in the global PPP and retirement village markets. Mean score analysis, normalization range method, Kendall’s coefficient of concordance and factor analysis were used for analysis. Findings – Results show that out of the 27 CSFs identified, the most significant ones in developing PPP retirement village projects are “the age-friendly design of villages”, “appropriate location of PPP retirement village”, “reliable and accessible health and physical facilities” and “effective social inclusion and integration in villages”. Further analysis shows that the 27 CSFs can be grouped into 7 major factor groupings, namely, “effective project monitoring”, “financial support”, “social integration”, “effective contractual arrangement between parties”, “government commitment and support”, “sustainable design of village” and “effective payment structure”. Originality/value – The outputs of this study will adequately inform retirement village developers, retirement village stakeholders and local government authorities of the best practices they should put in place to ensure the sustainable growth of the global retirement village market