Antibiotic and antiparasitic residues in surface water of urban rivers in the Red River Delta (Hanoi,Vietnam): concentrations,profiles, source estimation,and risk assessment

Environmental Science and Pollution Research - Antibiotic residues and antimicrobial resistance in surface water are issues of global concern, especially in developing countries. In this study, the...     

Kinetics of the adsorption and desorption of radionuclides of Co, Mn, Cs, Fe, Ag and Cd in freshwater systems: experimental and modelling approaches

The sorption and release kinetics of 54Mn, 58Co, 59Fe, 109Cd, 110mAg and 134Cs by freshwater suspended particles were investigated to better identify the biogeochemical processes involved and to obtain suitable data for improving models describing radionuclide migration in freshwater streams. In order to observe any seasonal variability in the interaction of radionuclides with natural particles, experiments were performed both in winter and in summer during a phytoplanktonic bloom. Two kinetic models are compared in this paper: the "one-step reversible" model, based on the hypothesis that the transfer of radionuclides between water and suspended solids is governed by a reversible reaction, and the "two-successive-step reversible" model, which assumes two distinct types of sites or reactions on the solid phase. The "one-step reversible" model is generally unable to describe properly the exchange kinetics; this result shows that at least two processes are generally involved in radionuclide exchange between water and suspended particles. On the contrary, a model involving the existence of two successive reversible reactions properly simultes both the sorption and release kinetics. The determination of the kinetic coefficients allows quantitative assessment of the relative importance and kinetics of the processes. In particular, it has been shown that, except for Cs and Cd, major fractions of the radionuclides are associated at equilibrium with particulate sites involving strong interactions. The kinetics to reach this equilibrium depend on seasonal conditions, especially for Co and Mn: the transfer of Co and Mn to particulate sites involving strong interactions is much slower in winter. The distribution of the radionuclides between water and particulate sites involving weak interactions also shows seasonal variations for Co, Mn, Fe and Ag: the capacity to associate radionuclides is much higher in summer for Co and Mn, while the inverse tendency is observed for Fe and Ag. For Cs and Cd, no significant seasonal differences were observed.     

Persistent organochlorine residues in human breast milk from Hanoi and Hochiminh City, Vietnam: contamination, accumulation kinetics and risk assessment for infants

Despite the ban on persistent organochlorines (OCs) in most of the developed nations, their usage continued until recently in many Asian developing countries including Vietnam, for agricultural purposes and vector-borne disease eradication programs. In this study, we collected human breast milk samples from the two big cities in Vietnam: Hanoi (n=42) and Hochiminh (n=44) and determined the concentrations of persistent OCs such as PCBs, DDT and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), chlordane compounds (CHLs) and tris-4-chlorophenyl-methane (TCPMe). The contamination pattern of OCs was in the order of DDTs > PCBs > HCHs > CHLs approximately HCB approximately TCPMe. Compilation of available data indicated that DDT residue levels in human breast milk from Vietnam were among the highest values reported for Asian developing countries as well as developed nations. This result suggests recent usage of DDTs in both north and south Vietnam. Interestingly, in both cities, the p,p'-DDT portion was higher in multiparas than those in primiparas. Considering the fact that the interval between the first and the second child of a mother in Vietnam is usually short, this result probably indicates continuous intake of DDTs in the population. Analysis of infant exposure to DDTs via breast milk suggested that the daily intake rates for number of individuals are close to or above the threshold for adverse effects which may raise concern on children health.     

Multicomponent photocatalysts for synergic removal of antibiotics in aqueous media: a review

Environmental Chemistry Letters - Pollution of waste and natural waters by antibiotics is a major health issue that induces the development of resistant pathogens. Pollutant may be removed by...     

The forest frontier in the Global South: Climate change policies and the promise of development and equity

Halting forest loss and achieving sustainable development in an equitable manner require state, non-state actors, and entire societies in the Global North and South to tackle deeply established patterns of inequality and power relations embedded in forest frontiers. Forest and climate governance in the Global South can provide an avenue for the transformational change needed—yet, does it? We analyse the politics and power in four cases of mitigation, adaptation, and development arenas. We use a political economy lens to explore the transformations taking place when climate policy meets specific forest frontiers in the Global South, where international, national and local institutions, interests, ideas, and information are at play. We argue that lasting and equitable outcomes will require a strong discursive shift within dominant institutions and among policy actors to redress policies that place responsibilities and burdens on local people in the Global South, while benefits from deforestation and maladaptation are taken elsewhere. What is missing is a shared transformational objective and priority to keep forests standing among all those involved from afar in the major forest frontiers in the tropics.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01602-1.     

Self-build packed-bed bioreactor for rapid and effective BOD estimation

This work demonstrated a simple, low-cost, rapid, and effective biochemical oxygen demand (BOD) estimation system based on a packed-bed bioreactor that can be easily self-built on-site at a particular wastewater treatment plant for continuous monitoring of the influent and effluent. The use of natural microbial consortium that were collected from the target wastewater and immobilized on a cheap porous carrier simply by adhesion resulted in an acceptable accuracy of over 95%. The newly developed semi-continuous operating mode with peak-type signals was shown to be able to continuously estimate BOD at a high flow rate to overcome the flow dependence of the oxygen electrode, limit clogging issues, enhance the response time, and lower the limit of detection. The resulting packed-bed bioreactors could work continuously for 22 h with a coefficient of variance (CoV) of only 1.8% or for 13 h a day for several days with a maximum CoV of 1.4% and their response was observed to be stable over 80 consecutive measurements. They exhibited stable responses at a wide pH range of 6.5–8.5, which is also the recommended range for aerobic wastewater treatment, emphasizing the greater ease of use of natural microorganisms for BOD estimation.

     

Temporal changes of 7Be, 137Cs and 210Pb activity concentrations in surface air at Monaco and their correlation with meteorological parameters

Results of analysis of ⁷Be, ¹³⁷Cs and ²¹⁰Pb on aerosol filters carried out from 1998 to 2010 in Monaco show that a weak correlation between activity concentrations of these radionuclides in the atmosphere and meteorological parameters has been found for ⁷Be and temperature (r = 0.50), ²¹⁰Pb and temperature and humidity (r = 0.43 and 0.41, respectively), and ¹³⁷Cs and precipitation (r = 0.51). The minimum and maximum ⁷Be activity concentrations were observed during 2000 and 2009, corresponding with the maximum and minimum solar activity, respectively. The maximum ¹³⁷Cs activity concentration found in May-June 1998 was due to the accident at Algeciras in Spain. The deposition velocities of ⁷Be, ¹³⁷Cs and ²¹⁰Pb depended on the precipitation rate, and attained maximum values during dry seasons. The investigated radionuclides may be used as atmospheric tracers, especially in long-term periods.     

Sustainability indicators for clean development mechanism projects in Vietnam

The Clean Development Mechanism (CDM) is one of the flexible instruments of the Kyoto Protocol designed to combat climate change so as to bring advantages to developing countries and developed countries alike. Indeed, CDM projects have a two-fold objective: to offset greenhouse gas emissions and to contribute to sustainable development in the host country. However in many cases, the latter objective appears to be marginalized. This is at least partly due to the difficulties surrounding the definition and the measurement of sustainability, in particular in a developing country context. To assess CDM projects’ contribution to sustainable development in the host country, scholars and practitioners need adapted indicator sets. A set of indicators were developed by way of an iterative Delphi approach amongst selected Vietnamese experts. The Delphi approach allowed a systematic collection of the experts’ judgements on the sustainability indicators through a set of sequentially applied questionnaires, interspersed with feedback from earlier responses. This exercise resulted in the selection of a set of 36 indicators, which emphasise economic efficiency, public health and pollution issues. The exercise yielded a locally supported and context-specific set of sustainability indicators that will allow Vietnamese decision-makers to enhance the sustainability of the approved CDM projects. In the future this set should be continually improved through real-life application and further participation from local stakeholders. This study is a first step in a long-term process towards developing an adapted toolkit for sustainability assessment of CDM projects in Vietnam.     

Measuring the association of environmental,corporate, financial,and social CSR: evidence from fuzzy TOPSIS nexus in emerging economies

Environmental Science and Pollution Research - The purpose of this research is to measure the combing impact of corporate social responsibility on company performance and to conduct a comparative...