VNUHCM Journal of Earth Science and Environment

Developing a set of appropriate criteria on production technology and environmental treatment for steel product manufacturing facilities with hot dip zinc plating process in Ba Ria - Vung Tau Province

Ho Minh Dung — 2025-06-18

Ba Ria - Vung Tau (BRVT) is a province with a lot of potential for industrial development and is prioritizing attracting investment in supporting industry development - an industry group that almost always needs the plating process to complete product improvement. However, in project investment approval, projects with production technology processes including the plating process will encounter barriers due to Decision No. 2214/QD-UBND dated August 16, 2016 of the People's Committee of BRVT province. Therefore, it is necessary to develop a set of appropriate criteria to evaluate production and waste treatment technology to have a basis for adjusting investment attraction criteria more appropriately for the above industry group. The study analyzed the current state of operations of steel product factories in the province, focusing on projects with galvanizing processes. Actual investigation and collection of detailed assessments of production technology and waste treatment technology at factories. Combined with the expert consultation method and Analytical Hierarchy Process method, the study has screened and proposed an appropriate set of criteria to evaluate production technology and environmental treatment at steel product manufacturing facilities. The hot-dip galvanizing process includes 04 groups of criteria with 11 specific criteria. Initially, the assessment was applied at 5 factories manufacturing and processing steel products. According to the evaluation results, the selected factories are all classified as having a fair and high level of suitability in production technology and waste treatment. This result shows that the factories pay great attention to production technology and environmental treatment. In addition, the study has proposed directions to adjust criteria for considering and attracting investment for industrial groups that use galvanizing in general and hot-dip galvanizing in particular in the province.

Application of quantum geographic information system (QGIS) changes water quality index (WQI) according to seasons of Thi Tinh River

Tuyet Thi Le — 2025-06-30

Research on the application of geographic information system (QGIS) to assess seasonal water quality (WQI) changes of Thi Tinh river to provide a database to contribute additional data sources to support the management of surface water resources of Binh Duong province. The results of calculating the WQI (Water Quality Index) from water quality monitoring locations of the Thi Tinh river in the rainy and dry seasons for many years, the study used Quantum Geographic Information Systems (QGIS) to interpolate the WQI results, create maps to compare and evaluate CLN over space and time. Average WQI of the area from bordering Binh Phuoc province, Cam Xe stream, Phu Binh bridge (WQI = 75-97); area from Phu Binh bridge, Cau Quan stream, bridge on Ring Road 4 from (WQI =73-88); area from bridge on Ring Road 4 to Ong Co bridge, location flowing to Saigon River (WQI = 77-92). Water quality on Thi Tinh River in the rainy season is better than water quality in the dry season. Thi Tinh river water quality in 2023 and 2024 is better than in 2022, and water quality in all seasons in 2023 and 2024 tends to be stable and less variable than the same period in 2022. Research to establish a map The surface water quality interpolation map on the Thi Tinh River contributes additional data sources to support the surface water source of Binh Duong province.

Performance comparison of conventional biological treatment process and membrane bioreactor treating common industrial effluent

Tran Cong Sac — 2025-06-30

Industrial effluent is challenging for wastewater treatment plants due to its complexity, toxicity and variable composition. This study aimed to evaluate the efficiency of industrial wastewater treatment between a lab-scale membrane bioreactor (MBR) and a full-scale anoxic/oxic (A/O) process. The wastewater used was after primary sedimentation tank, which involved lime or ferric coagulant. The results showed that the treated water quality from both systems was satisfied the national effluent standard for wastewater (column B of QCVN 40-MT:2011/BTNMT). The effluent from A/O process contained 74 ± 11 mg/L of COD, 8.3 ± 1.9 mg/L of TN, 1.6 ± 0.6 mg/L of TP, and 201± 38 Pt-Co of color. Meanwhile, the concentrations of COD, TN, TP, and color in the effluent of MBR system were 88 ± 21, 23.2 ± 4.6, 0.3 ± 0.2 mg/L, and 220 ± 98 Pt-Co, respectively. The removal rates of COD, TN, TP and color of anoxic/oxic process were 234 ± 119, 16 ± 3, 0.3 ± 0.2 mg/L.day, 213 ± 58 Pt-Co/L.day, respectively. The removal rates of COD, TN, TP, and color in MBR system were 1.6, 1.3, 10.3, and 2.1 times higher than those in the A/O process, respectively. Although the A/O process in industrial zones performed well, the MBR system demonstrated higher removal rates, particularly for nutrient removal. Besides, MBR systems offer several advantages, including reduced excess sludge production and less space requirements compared to A/O process. In general, MBR offers a promising solution for industrial wastewater treatment, with strong potential for application in industrial zones.

Evaluation of the surface water system using statistical method (PCA, FA AND ANOVA): a case study of Binh Thuan province, Vietnam

Thang Viet Le — 2025-06-30

This study aimed to assess the spatial and temporal variations in surface water quality in Binh Thuan Province and identify the underlying causes of pollution affecting regional water resources. The comprehensive assessment was based on surface water monitoring data systematically collected from 2016 to 2019, totaling 24 strategically positioned monitoring sites distributed across three distinct areas: 12 sites in upstream domestic water supply areas, 4 sites in downstream domestic water supply areas, and 8 sites in downstream non-domestic water supply areas. Water quality parameters were monitored quarterly throughout the study period, with sampling conducted twice during the rainy season and twice during the dry season to capture seasonal fluctuations. A total of 14 water quality parameters were collected at each monitoring event and rigorously compared against national water quality standards established by the Ministry of Natural Resources and Environment. The entire dataset was subjected to sophisticated statistical analysis employing multiple analytical approaches, including Principal Component Analysis and Factor Analysis (PCA/FA), two-way Analysis of Variance (ANOVA), and Water Quality Index (WQI) calculations. Statistical results from PCA/FA successfully identified five principal factors that significantly influence surface water quality conditions: domestic wastewater discharge, industrial activities, agricultural activities, saltwater intrusion, and meteorological conditions, collectively accounting for 54.52% of the total variance in the dataset. ANOVA analysis revealed that surface water quality in Binh Thuan Province exhibited distinct spatial and temporal variations throughout the monitoring period. WQI calculations demonstrated that water quality systematically declined from upstream to downstream areas and was consistently superior during the rainy season compared to the dry season. The comprehensive findings contribute significantly to elucidating the complex impacts and characteristics of socio-economic development activities on surface water quality in Binh Thuan Province, thereby providing valuable scientific evidence to assist provincial authorities in developing effective water resource protection strategies to support sustainable socio-economic development objectives.

Google Earth Engine application evaluates the relationship between storage changes and flow fluctuations in the Saigon-Dong Nai River basin

Hien Trong Dieu Le — 2025-06-30

This research utilized the Google Earth Engine (GEE) platform to estimate and analyze water storage dynamics within the Saigon-Dong Nai River basin in Vietnam, leveraging advanced remote sensing datasets related to evapotranspiration (ET) and precipitation (P). Specifically, two primary sources of input data were employed: evapotranspiration estimates derived from MODIS (Moderate Resolution Imaging Spectroradiometers) data, which provided comprehensive spatial coverage across the basin, and precipitation data obtained from the CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) satellite product. These datasets enabled a detailed examination of hydrological changes over the period from 2000 to 2019. The research further explored the correlation between fluctuations in stream-flow and changes in water storage during this timeframe. The results of the study revealed distinct seasonal patterns in water storage. Each year, from January to April, water storage exhibited a negative trend, primarily due to increased rates of evaporation coupled with reduced precipitation. Conversely, the period from May to October, which corresponds to the rainy season, saw a substantial increase in water storage variation. This positive change was attributed to higher precipitation, along with decreased solar radiation and lower temperatures, which collectively reduced evapotranspiration losses. Statistical analysis demonstrated a positive correlation between precipitation and evapotranspiration, as well as between water storage and stream-flow. The correlation coefficient between storage and stream-flow variability was found to be relatively low (R=0.38), yet it was statistically significant (p<0.05). The methodological approach adopted in this study can be readily applied to similar hydrological investigations in other river basins. Furthermore, the insights gained from these findings offer valuable support for water resource managers in developing and implementing more effective and sustainable water management policies.

Utilizing pineapple peel crosslinked chitosan as an eco-friendly biosorbent for heavy metal removal: A circular economy perspective

Nguyen My Linh — 2025-06-30

This study fabricated chitosan beads obtained from pineapple peels as sustainable biosorbents for hexavalent chromium (Cr (VI)) extraction from water, thus supporting circular economy initiatives. Heavy metal pollution in water systems is a crucial environmental issue that has serious consequences for human health, aquatic ecosystems, and the overall environment. Heavy metals such as lead (Pb), cadmium (Cd), chromium (Cr), zinc (Zn), and copper (Cu) are particularly problematic since they are non-biodegradable, tend to bioaccumulate in organisms, and have the ability to impair cellular function, posing long-term ecological and public health problems. Two biosorbents, PPA (glutaraldehyde crosslinked) and PPB (citric acid crosslinked), were synthesized and investigated using SEM and FTIR to investigate the structural and functional changes caused by the crosslinking agents. While PPB included more carboxyl groups due to citric acid crosslinking, FTIR analysis confirmed the presence of functional groups required for Cr (VI) binding. With optimal Cr (VI) removal at pH 3.0, testing results revealed maximal adsorption capacities of 18.87 mg/g for PPA and 21.01 mg/g for PPB. Increased availability of functional groups and adsorption surface stability improve PPB performance. Adsorption isotherm analysis revealed that both biosorbents followed the Freundlich model, indicating a heterogeneous adsorption mechanism. Kinetic investigations identified pseudo-first-order chemisorption as the major mechanism. Thermodynamic investigation revealed negative Gibbs free energy values (∆G), confirming the spontaneous nature of Cr (VI) adsorption. With PPB showing improved performance, this study demonstrates the efficacy of chitosan beads generated from pineapple peels as a sustainable and low cost biosorbent for heavy metal cleanup. The findings emphasize the importance of crosslinking agents in improving biosorbent performance, giving valuable information for the development of efficient and cost-effective wastewater treatment methods aligned with sustainability and circular economy concepts.