The study aimed to appraise groundwater quality in the Mekong Delta using a groundwater quality index (GWQI) and estimate human health risks associated with groundwater consumption. Groundwater samples were collected at sixty wells distributed in An Giang, Kien Giang, Hau Giang and Dong Thap provinces. Twelve water quality parameters were measured, including pH, total dissolved solids (TDS), hardness, coliform, nitrate (NO3ˉ), nitrite (NO2ˉ), ammonium (NH4+), sulfate (SO42-), iron (Fe), manganese (Mn), arsenic (As) and cadmium (Cd). The results were compared with the national regulation on groundwater quality. The findings of this study indicated that groundwater in the Mekong Delta was contaminated with microorganisms and some heavy metals (Fe, Mn, and As). This was related to anthropogenic activities, such as improperly treated domestic wastewater and agricultural and industrial wastes. Based on the results of GWQI, 30% of the total groundwater samples in the Mekong Delta were classified as very good for drinking purposes. However, over 26% of all samples were unsuitable for drinking. In terms of risk assessment, children were rather susceptible to cancer risks and adverse health effects through drinking As-contaminated groundwater than adults. The cancer risks of consuming As-contaminated groundwater for children and adults were up to 4.28×10-3that is higher than the acceptable risk. The highest aggregate hazard quotient of heavy metal-contaminated groundwater for children and adults was 9.54, which means that they could suffer adverse health effects. Groundwater is an indispensable source of freshwater in the Mekong Delta; thus, home water treatments are recommended to protect public health, and an in-depth groundwater quality and health risk assessment should be conducted. Doi: 10.28991/CEJ-2023-09-03-09 Full Text: PDF

Reusing and recycling laptops has many positive benefits, both environmentally and economically. Therefore, this study was conducted with the objectives of assessing (1) the current state of ownership, (2) the current state of use and disposal, and (3) quantifying the potential reuse and recycling of laptops for students at Can Tho University, Vietnam. Based on data collected by document review and face-to-face interviews with students, with a usage rate of 1 laptop per student, it is estimated that the whole of Can Tho University has 42,918 laptops in use. The actual use lifespan of the laptop is 5.28 years, lower than the expected lifespan of 6.8 years. The results of the correlation analysis show that the actual usage life does not have any correlation with the consumption behavior of students. In addition, the study estimates that 96.67% of laptops will be disposed of before 2031. In which, the potential for direct reuse is 2.33%, reuse with support is 88.33%, and recycling is 9.33%. The results show that universities have great potential to implement safe e-waste collection and treatment activities. Doi: 10.28991/CEJ-2023-09-06-013 Full Text: PDF

The objective of this study was to evaluate seasonal fluctuations in groundwater quality, determine the effects of different stressors on this resource, and recognize the potential pollution sources in a coastal region of southern Vietnam. Eleven samples collected in Ben Tre province during the dry and wet seasons were then analyzed for sixteen parameters, including pH, total dissolved solids (TDS), salinity, total hardness (TH), ammonium (NH₄⁺-N), nitrite (NO₂ˉ-N), nitrate (NO₃ˉ-N), sulfate (SO₄²ˉ), chloride (Clˉ), iron (Fe), manganese (Mn), lead (Pb), mercury (Hg), arsenic (As), coliforms, and Escherichia coli (E. coli). Pearson correlation analysis, principal component analysis (PCA), and cluster analysis (CA) were employed. The results indicated that total dissolved solids, salinity, total hardness, Clˉ, E. coli and coliform were detected as contaminants in groundwater samples. The trend of fluctuations in the parameters was mostly higher in the dry season. Which Mn and coliform significantly fluctuated between the dry and wet seasons. Activities in industrial-craft areas, landfills and seawater-intruded areas negatively impacted groundwater quality, typically TDS in industrial-craft areas, coliform and E.coliat the landfill area. Six principal components obtained from PCA could explain 93.6% of the variance, and all parameters are responsible for variations in groundwater quality. Geology, discharged wastewater, landfill leachate, agricultural activities, and saltwater intrusion can be considered representative factors. CA grouped the collected samples into four clusters based on the similarity in water properties. The analysis results showed that the locations in each cluster have outstanding water quality characteristics, clusters I and III have high TDS characteristics, cluster II has coliforms, and cluster IV sets of locations with high salinity. This study is promised to partially fill the gap in comprehensive information on groundwater quality in the coastal province so that policymakers can develop sustainable water management strategies in the future. Doi: 10.28991/CEJ-2023-09-03-01 Full Text: PDF

The study aimed to assess the relationship between surface water quality and the diversity of planktonic communities in An Giang province, Vietnam. The national technical regulations on surface water quality, the water quality index (WQI), and the Shannon-Wiener diversity index (H') were applied to evaluate water quality. The considerable influence of water quality parameters on the dominant plankton was determined by canonical correspondence analysis (CCA) and similarity percentage analysis (SIMPER). The results showed that water quality was contaminated by organic matter, total suspended solids (TSS), and microorganisms. WQI values classified water quality as ranging from bad to good. The species composition of phytoplankton was dominated by two phyla, Chlorophyta and Bacillariophyta, and that of zooplankton was the Rotifera group. SIMPER analysis identified phytoplankton species with dominant density, including Melosira granulata, Pediastrum duplex, Anabaena sp., and Lyngbya circumcreta. Microcyclops varicans, Filinia longiseta, Trichocerca pusilla, Copepoda nauplius, Brachionus caudatus, and Polyarthra vulgarisdominated the density of zooplankton. Temperature, pH, TSS, ammonium, orthophosphate, and coliform considerably influence the dominant species composition of plankton. However, the indicators of diversity and composition of plankton were unable to completely reflect water quality. These findings could contribute to the indicator selection in developing the monitoring water quality programs. Doi: 10.28991/CEJ-2023-09-05-011 Full Text: PDF