Review of Chloride Ion Detection Technology in Water

The chloride ion (Cl−) is a type of anion which is commonly found in the environment and has important physiological functions and industrial uses. However, a high content of Cl− in water will do harm to the ecological environment, human health and industrial production. It is of great significance to strictly monitor the Cl− content in water. Following the recent development of society and industry, large amounts of domestic sewage and industrial sewage are discharged into the environment, which results in the water becoming seriously polluted by Cl−. The detection of Cl− has gradually become a research focus. This paper introduces the harm of Cl− pollution in the environment and summarizes various Cl− detection methods, including the volumetric method, spectrophotometry method, electrochemical method, ion chromatography, paper-based microfluidic technology, fluorescent molecular probe, and flow injection. The principle and application of each technology are described; their advantages, disadvantages, and applicability are discussed. To goal of this research is to find a more simple, rapid, environmental protection and strong anti-interference detection technology of Cl−.

Effect of High-Speed Railways on City Industrial Sewage Discharge

Industrial wastewaters threatening the sustainability of society have increasingly become a key social issue across the globe. Consequently, countermeasures have been suggested across a broad range of research fields and policy cycles in both industrialized and industrializing countries. Thus, identifying factors that drive reductions in industrial wastewater discharge is a key task in the water research and policymaking fields. In contrast to previous studies that have focused on reducing industrial wastewater discharge through techniques, policy, management, and other tools, the aim of this study was to investigate the effect of transport infrastructure development, particularly high-speed railways (HSR), on industrial sewage discharge. Given the rapid development of high-speed railways in China and the country’s severe water pollution, China was our research context, and our sample was 298 prefecture-level Chinese cities during the period 1999–2018. The empirical results show that cities with high-speed railways have greater reductions in industrial wastewaters, and that these effects are weakened in cities with a more developed economy and information environment. The results are consistent when using different methods to test their robustness, such as time-varying difference-in-difference (DID), instrumental variables, and placebo tests. These findings offer useful guidance for practitioners and policymakers in the management of water resources and the development of transport infrastructure in cities. These results contribute to the literature in the field of water management and to the assessment of the broader effect of high-speed railways.

A Review on the Performance of Concrete Containing Non-Potable Water

Construction industries consume huge amounts of potable water during activities such as washing of aggregates, stone crushing, manufacturing, and curing of concrete, mortars, grouts, and wetting of masonry bricks. It is also responsible for wastewater generated during the finishing and cleaning of buildings and construction equipment. Therefore, the water-footprint of construction industry cannot be ignored to reach the state-of-the art sustainability. This study reviewed the technical properties of construction materials made with non-potable water (NPW), i.e., domestic and industrial sewage. The study identified the positive and negative effects of non-potable water on the fresh- and hardened-state properties of concrete. This study also identified the gaps in the literature that can be analysed in order to produce reliable information related to the use of different types of NPW on the properties of concrete.

Identification of Industrial Sewage Sludge based on Heavy Metal Profiles: A Case Study of Printing and Dyeing Industry

The illegal disposal of industrial sewage sludge has caused serious environmental pollution. To develop identification techniques of industrial sewage sludge based on the characteristic fingerprints carried by sewage sludge itself is a promising method that is helpful to clarify the responsibility of illegal enterprises. In this study, heavy metal composition and speciation of sewage sludge from industries (including printing and dyeing industry and other industries) and municipal sewage treatment plant located in eastern China were determined and their performance of classification was evaluated by principal component analysis (PCA) and linear discrimination analysis (LDA). Results showed that heavy metal composition and speciation can be an effective tool for distinguishing sewage sludge between printing and dyeing industry and other industries, with an accuracy rate of 82.9% and 100%, respectively. Antimony (Sb) and zinc (Zn) are two characteristic heavy metals, which can be used to identity sewage sludge in printing and dyeing sub-industries with an accuracy rate of 90%. The combination of these three methods may be a precise and promising tool for identification of sewage sludge between industries and sub-industries. This study developed a potential method for tracing the industrial sources of sewage sludge and establishing the identification database of industrial sewage sludge, and provided technical support for the government to supervise the illegal dumping and disposal of industrial sewage sludge.