http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/18689 2026-07-15T03:53:17Z 2026-07-15T03:53:17Z Yang, Xiaojing Nguyen, Van Bach Lei, Zhongfang Le, Xuan Sinh Bui, Thi Minh Hien http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21782 2026-07-15T03:25:26Z 2026-07-15T00:00:00Z

Title: Bioremediation and nutrients removal from wastewater by algal-bacterial granular sludge under two Cr(VI) exposure patterns Authors: Yang, Xiaojing; Nguyen, Van Bach; Lei, Zhongfang; Le, Xuan Sinh; Bui, Thi Minh Hien Abstract: Algal–bacterial granular sludge (ABGS) is promising for simultaneous heavy metal bioremediation and nutrients removal. However, its long-term stability and adaptive behavior under chronic low-level heavy metal stress and different exposure patterns remain poorly understood. In this study, the performance and stability of ABGS were systematically compared during 95-day intermittent and continuous exposure to 2 mg/L Cr(VI)-containing wastewater. Both exposure patterns resulted in decreased granular sludge settleability and chlorophyll a content, while granular structural integrity was well maintained, with integrity coefficient reaching a final value of 1.4 %. Nutrient removal was initially inhibited but rapidly recovered to approximately 80 % total phosphorus and 70 % total nitrogen by the end of test period. Notably, intermittent Cr(VI) exposure was more conducive to the recovery of microbial activity than continuous exposure, indicating a stronger adaptive resilience of ABGS under fluctuating stress conditions. The two exposure patterns showed only minor differences in Cr(VI) removal, and both exhibited enhanced extracellular polymeric substances secretion and Ca/Fe accumulation within granules, facilitating Cr immobilization. These findings highlight the long-term resilience and adaptive responses of ABGS under chronic low-level Cr(VI) stress in addition to the critical role of exposure patterns in shaping system stability and microbial activity. This study provides new insights into optimization of biological treatment strategies for long-term treatment of heavy metal-containing wastewater in practice.

2026-07-15T00:00:00Z Vu, Duy Vinh Ouillon, Sylvain Nguyen, Minh Hai http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21781 2026-07-15T03:14:21Z 2026-07-15T00:00:00Z

Title: Coastal water level trends and ENSO-related variability in the northeastern Mekong Delta (1979–2024) Authors: Vu, Duy Vinh; Ouillon, Sylvain; Nguyen, Minh Hai Abstract: Coastal water levels in the northeastern Mekong Delta exhibit pronounced long-term trends and interannual variability linked to large-scale climate forcing. Using tide-gauge observations at the Vam Kenh station (1979–2024) and CMEMS (Copernicus Marine Environment Monitoring Service) satellite altimetry (1993–2024), we assess long-term, seasonal, and ENSO-related water level variability. The results reveal a statistically significant and evidence of recent acceleration inferred from sub-period trends in mean relative water level, with rates exceeding approximately 6 mm yr⁻¹ over the last two decades (2005–2024), compared to about 5 mm yr⁻¹ over the full 46-year record. Seasonal variability shows modulation of the rise by the monsoon cycle, with faster increases during the northeast monsoon and slower rises during the southwest monsoon. Interannual variability is clearly modulated by the El Niño–Southern Oscillation, with strong La Niña events elevating water levels by up to about 5 cm in anomaly magnitude, while El Niño phases are generally associated with negative anomalies. Atmospheric pressure acts as a secondary control, contributing approximately 5–20 % of interannual variance through the inverse barometer effect. Tide-gauge and CMEMS data exhibit strong agreement (r = 0.95), supporting their combined use for coastal monitoring. Overall, the results highlight accelerating relative rise in a subsiding deltaic environment, with important implications for coastal vulnerability.

2026-07-15T00:00:00Z Jiang, Binbin Fan, Daidu Huang, Qinghui Li, Xueding Nguyen, Dac Ve Ren, Fahui Yu, Junyu Boss, Emmanuel http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21780 2026-07-15T02:52:45Z 2026-01-01T00:00:00Z

Title: Evaluation of Different Approaches for Assessing Water Quality Using Sentinel-2/MSI: A Case Study in Coastal Ningde Authors: Jiang, Binbin; Fan, Daidu; Huang, Qinghui; Li, Xueding; Nguyen, Dac Ve; Ren, Fahui; Yu, Junyu; Boss, Emmanuel Abstract: Water quality observations are vital for effectively managing coastal resources and influencing decisions from emergency beach closures to aquaculture leasing agreements. This study focuses on deriving two water quality parameters—Chlorophyll a (Chl-a) and suspended particulate matter (SPM)—through the high-resolution multispectral imager (MSI) onboard the Sentinel 2A&B satellites, specifically for the Ningde coastal region, which is a crucial aquaculture hub in China. Since more than 90% of the signals captured by satellites are affected by atmospheric interference, it is crucial to apply a process called “atmospheric correction” (AC) to isolate the water contribution, known as water leaving reflectance, from the radiance measured at the top of the atmosphere. Our research assesses five published AC models and various algorithms designed to accurately estimate Chl-a and SPM from water leaving reflectance. We determine the most effective combination by comparing these findings against in situ data gathered from eleven locations in the Ningde coastal region (POLYMER-SOLID with lowest metric RMSLE (0.29), and MAE (1.68) and POLYMERMDN with the lowest metric RMSLE (0.59), and MAE (0.56)). Our study underscores the importance of selecting locally validated AC models and algorithms for generating water quality products, as this enhances the utility of remote sensing data in monitoring water quality. Moreover, we conduct a spatiotemporal analysis of the water quality parameters from 2016 to 2021, revealing significant interannual variability that underlines the need for continuous monitoring and robust data analysis in coastal management efforts.

2026-01-01T00:00:00Z Nguyen, Van Thao Do, Cong Thung Sarti, Massimo Do, Thi Thu Huong Bavestrello, Giorgio Cerrano, Carlo Calcinai, Barbara Negri, Alessandra Sabbatini, Anna http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21779 2026-07-15T02:52:24Z 2026-01-01T00:00:00Z

Title: When Growth Meets Heritage: Rethinking Sustainability in a Vietnam’s Coastal Frontier Authors: Nguyen, Van Thao; Do, Cong Thung; Sarti, Massimo; Do, Thi Thu Huong; Bavestrello, Giorgio; Cerrano, Carlo; Calcinai, Barbara; Negri, Alessandra; Sabbatini, Anna Abstract: This paper re-examines and synthesizes environmental and biodiversity data collected between 1995 and 2004 to reconstruct a reference baseline for the Hai Phong–Quang Ninh coastal system prior to Vietnam’s most transformative phase of socio-economic development. This period—captured through extensive Vietnam–Italy scientific cooperation— documents one of the last scientifically recorded states of near-pristine environmental conditions in Ha Long Bay and its adjoining coastal waters, offering an indispensable benchmark for evaluating the magnitude and direction of change over the past twenty-five years. Over the past two decades, Vietnam’s coastline has undergone profound transformation driven by industrial expansion, port construction, aquaculture, and mass tourism. Yet it remains unclear whether this growth has been sustainably absorbed by ecosystems of global significance, including the UNESCO World Heritage seascape of Ha Long–Cat Ba. By reinterpreting early-2000s baseline datasets, this paper provides a reference against which current and future ecological trajectories can be assessed and proposes indicator frameworks to support integrated coastal zone management and World Heritage conservation. Ultimately, the analysis highlights the enduring tension between rapid development and heritage protection, and it questions whether sustainable development in such complex coastal systems remains an achievable outcome or an aspirational ideal.

2026-01-01T00:00:00Z Cao, Thi Thu Trang Pham, Thi Kha Tran, Anh Tu Dinh, Van Nhan Le, Van Nam Nguyen, Dac ve http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21778 2026-07-15T02:53:15Z 2026-01-01T00:00:00Z

Title: Assessment of pollution load from socio economic activities discharged into coastal areas: case study of Quang Tri province (Vietnam). Authors: Cao, Thi Thu Trang; Pham, Thi Kha; Tran, Anh Tu; Dinh, Van Nhan; Le, Van Nam; Nguyen, Dac ve Abstract: Quang Tri Province, located in the central region of Vietnam at the southern gateway to the Gulf of Tonkin, includes coastal areas and Con Co Island, which serve as important habitats and breeding grounds for high economic value marine species. Using rapid environmental assessment methods and direct measurements at discharge sources, the amount of waste discharged into coastal waters has been estimated. Each year, socio-economic development activities of Quang Tri province discharge approximately 23.5 thousand tons of COD, 8.5 thousand tons of N-T, over 650 tons of P–T and about 125 thousand tons of TSS into the coastal waters. The discharged amounts represent 13% to 78% of the total waste generated for each pollutant. Among the generated waste sources in the province, livestock and poultry activity contribute to the largest share, followed by domestic and industrial source. Meanwhile, the capacity to treat domestic wastewater in urban areas only reaches about 11%; the capacity to treat livestock and poultry waste reaches about 60%; and industrial waste treatment infrastructure is still inadequate and underfunded. To minimize the amount of waste discharged into the coastal waters, Quang Tri Province must increase investment in source-level waste treatment and strengthen environmental management measures.

2026-01-01T00:00:00Z