Profiles and removal efficiency of polycyclic aromatic hydrocarbons by two different types of sewage treatment plants in Hong Kong

Sewage discharge could be a major source of polycyclic aromatic hydrocarbons(PAHs) in the coastal waters. Stonecutters Island and Shatin Sewage Treatment Works(SCISTW and STSTW)in Hong Kong, adopted chemically enhanced primary treatment and biological treatment,respectively. This study aimed at(1) determining the removal efficiencies of PAHs,(2) comparing the capabilities in removing PAHs, and(3) characterizing the profile of each individual PAHs, in the two sewage treatment plants(STPs). Quantification of 16 PAHs was conducted by a Gas Chromatography. The concentrations of total PAHs decreased gradually along the treatment processes(from 301 ± 255 and 307 ± 217 ng/L to 14.9 ± 12.1 and 63.3 ± 54.1 ng/L in STSTW and SCISTW, respectively). It was noted that STSTW was more capable in removing total PAHs than SCISTW with average total removal efficiency 94.4% ± 4.12% vs. 79.2% ± 7.48%(p 0.05). The removal of PAHs was probably due to sorption in particular matter, confirmed by the higher distribution coefficient of individual and total PAHs in solid samples(dewatered sludge contained92.5% and 74.7% of total PAHs in SCISTW and STSTW, respectively) than liquid samples(final effluent-total contained 7.53% and 25.3% of total PAHs in STSTW and SCISTW, respectively).Despite the impressive capability of STSTW and SCISTW in removing PAHs, there was still a considerable amount of total PAHs(1.85 and 39.3 kg/year, respectively for the two STPs) being discharged into Hong Kong coastal waters, which would be an environmental concern.     

Fetal methylmercury exposure as measured by cord blood mercury concentrations in a mother-infant cohort in Hong Kong

This study was designed to examine newborn infants in Hong Kong prenatally exposed to levels of methylmercury considered to increase risk of neurotoxic effects and to examine subject characteristics that modify the degree of prenatal mercury exposure. Mercury concentrations in 1057 sets of maternal and cord blood samples and 96 randomly selected maternal hair samples were measured. Subject characteristics were measured or collected by questionnaire. Of the 1057 cord blood samples collected only 21.6% had mercury concentrations less than 29 nmol/L (5.8 micro g/L). Median maternal hair mercury concentration was 1.7 ppm. The geometric mean cord to maternal blood mercury ratio was 1.79 to 1. Increasing maternal fish consumption and maternal age were found to be associated with increased cord blood mercury concentrations. Marine fish consumption increased cord blood mercury concentrations more than freshwater fish (5.09%/kg vs 2.86%/kg). Female babies, maternal alcohol consumption and increasing maternal height were associated with decreased cord blood mercury concentrations. Pregnant women in Hong Kong consume large amounts of fish and as a result, most of their offspring have been prenatally exposed to moderately high levels of mercury. In this population, pregnant women should choose freshwater over marine fish and limit fish consumption.     

Building disaster‐resilient micro enterprises in the developing world

Family‐owned micro enterprises operating within the informal sector of most developing countries provide millions of citizens with a livelihood and are the economic backbone of many communities. Yet, the turbulence that emanates up or down respective supply chains following a disaster can cause these entities to fail. This study develops a model that recognises the relative weakness of micro enterprises to such disaster‐related shocks. The model proposes that micro enterprises can moderate the effect of such shocks by creating resilience through cognitive preparation, continuous learning, and the generation of various forms of social capital (cognitive, relational, and structural). The propositions for the model are established through an extensive literature review, coupled with examples drawn from the documents of humanitarian agencies performing disaster relief work in India. This model also serves as a preliminary basis with which to derive metrics to set benchmarks or to assess the viability of a micro enterprise's ability to survive disaster‐related shocks.     

Modeling ice cover effect on river channel bank stability

Environmental Fluid Mechanics - This paper presents a numerical model study on the ice cover effect on bank stability in non-cohesive alluvial channels. The model consists of a coupled...     

The outbreak of COVID-19 in Taiwan in late spring 2021: combinations of specific weather conditions and related factors

Environmental Science and Pollution Research - This study aimed to investigate the impact of weather conditions on the daily incidence of the COVID-19 pandemic in late spring 2021 in Taiwan, which...     

Quantile relationship between globalization,financial development,economic growth,and carbon emissions: evidence from Vietnam

Environmental Science and Pollution Research - Environmental quality and economic activity have a strong relationship. Carbon emissions remain one of the world’s most dangerous environmental...     

Characterization of Cu2+ adsorption for eco-hydroxyapatite derived from limestone sludge via hydrothermal synthesis

Journal of Material Cycles and Waste Management - This study developed a novel approach to the hydrothermal synthesis of eco-hydroxyapatite (eco-HPA) from recycled limestone sludge for the removal...     

Sustainable ternary cement blends with high-volume ground granulated blast furnace slag–fly ash

Environment, Development and Sustainability - Coal fly ash and granulated ground blast furnace slag (GGBS) are more widely used as supplementary cementitious materials in cement production. This...