Metal speciation in sediment and bioaccumulation in <Emphasis Type="Italic">Meretrix lyrata</Emphasis> in the Tien Estuary in Vietnam

The concentrations of seven toxic metals (cadmium (Cd), nickel (Ni), chromium (Cr), arsenic (As), lead (Pb), copper (Cu), and zinc (Zn)) were determined in sediments and the soft tissues of a bivalve species (Meretrix lyrata) collected from the Tien Estuary in Tien Giang Province, South Vietnam. The total metal concentrations in sediments (mg/kg dry weight) increased as Cd (0.06) < Cu (5.0) < Pb (13.9) < As (16.3) < Ni (24) < Cr (50) < Zn (62). Speciation analysis revealed that these metals existed mainly in the residual fraction (43–94%), followed by the Fe-Mn oxide-bound (5–35%) and organic/sulfide-bound (0.6–9.2%) fractions. The metal concentrations in M. lyrata (mg/kg dry weight) were in the ranges of 1.3–1.9 (Cd), 1.5–2.8 (Ni), 1.8–3.4 (Cr), 11–16 (As), 0.3–0.6 (Pb), 6.9–8.7 (Cu), and 95–128 (Zn), which are safe for human consumption. The order of the mean biota-sediment accumulation factor (BSAF) of the metals in the non-residual fractions of the sediment for M. lyrata was Cd > Cu > As > Zn > Cr > Ni > Pb. The Risk Assessment Codes (RACs) suggest that the highest mobility of Cd (with RAC = 37%) poses greater environmental risk to aquatic biota. Correlation analysis results show that M. lyrata can be used as a biomonitor of Cd and Cu pollution in the exchangeable, acid-soluble, and non-residual sediment fractions.     

Sustainable livelihoods development by utilization of geomorphological resources in the Bai Tu Long Bay,Quang Ninh Province,Vietnam

Located in the humid tropical zone and endowed with carbonate sedimentary formations, Vietnam has unique karst landscapes where caves, limestone, and dolines are common. If well managed, these are valuable geomorphological resources for a sustainable socio-economic development. Although publications on sustainable livelihoods associated with conserving biodiversity and local culture are plentiful, there is still a lack of studies linking livelihood quality with the conservation of geomorphological resources, in particular in karst areas. This study assesses the geomorphological resources in Vietnam’s Bai Tu Long Bay and studies the relationship between livelihood and these resources. The current research area Bai Tu Long Bay is adjacent to the natural World Heritage site of Ha Long Bay in the Vietnamese part of the Gulf of Tonkin. Bai Tu Long is characterized by a karst landscape, which is at the same time similar but also different from Ha Long Bay. A field survey and interviews with 153 households allowed assessing people’s perception of the value of the geomorphological resources and their importance for local income. The results show that Bai Tu Long Bay has abundant, diverse, and unique geomorphological resources, which are valuable for tourism development. However, the local people are unaware of these values likely because they have no direct benefit from them. Further a sustainable development strategy for Bai Tu Long Bay is recommended. The outcome is a proposal for tourism initiatives aiming at realizing more sustainability in the area.     

Nanotechnology for improved production of algal biofuels: a review

Environmental Chemistry Letters - Fossil fuel depletion and carbon dioxide emissions are calling for carbon neutral energies such as algal biofuels, yet actual production of agal biofuels is...     

Spatial and temporal variations of PAHs in surface sediments of estuarine and coast of CanGio wetland,Vietnam

Surface sediments from estuarine and coast of CanGio wetland (CGW) of Hochiminh City, Vietnam, were investigated to identify the spatial and temporal variations of polycyclic aromatic hydrocarbons (PAHs). The total PAHs showed wide variation but similar to patterns observed (F?=?0.901, p?=?0.46) in LongTau (31?±?77 ng/g dry weight, n?=?13), SoaiRap (53?±?81, n?=?4), ThiVai (60?±?62, n?=?10) estuaries, and coastal areas (112?±?211, n?=?9). A decreasing trend in the wet season (F?=?8.8, p?=?0.01) reflected that inland sources such as wastewater discharged and atmospherically transported contaminants contributed to PAHs in sediments. The risk posed by the PAHs in the coastal and estuarine areas of CGW is still negligible. The present study provides baseline data, which can be used for regular monitoring and future strategy of environmental protection for the study area.

     

On-site rainwater harvesting and treatment for drinking water supply: assessment of cost and technical issues

Environmental Science and Pollution Research - This study assessed the performance of rainwater-harvesting systems installed for selected public utilities in the northern provinces of Vietnam where...     

Primary biosorption mechanism of lead (II) and cadmium (II) cations from aqueous solution by pomelo (Citrus maxima) fruit peels

Environmental Science and Pollution Research - The present work investigates the primary adsorption mechanisms of lead (II) and cadmium (II) cations onto pomelo fruit peel (PFP) from aqueous...     

Simulating the spatial distribution of pollutant loads from pig farming using an agent-based modeling approach

Environmental Science and Pollution Research - This research developed an agent-based model (ABM) for simulating pollutant loads from pig farming. The behavior of farmer agents was captured using...     

Decarbonization of Vietnam’s economy: decomposing the drivers for a low-carbon growth

Environmental Science and Pollution Research - Vietnam has witnessed a rapid increase in national-level CO2 emissions due to rising urbanization, economic expansion, export growth, and industrial...     

Particulate matter in the cultivation area may contaminate leafy vegetables with heavy metals above safe levels in Korea

Environmental Science and Pollution Research - Among air pollutants, particulate matter (PM) has been identified as a major cause of environmental pollutants due to the advancement of industrial...