Modification of natural zeolite by salt to treat ammonia pollution in groundwater

Treating ammonium pollution in ground water by natural zeolite after being modificated to the Naform (Z-Na) is the new way of research that scientists interested in. The experiment results showed that, at pH 6, the efficient of treating ammonium in ground water is the highest. The efficient of treating increase rapidly in the first 5 minutes and remain stable after that. Higher concentration of the Z-Na will increase the treating coefficient of the process. With a water sample that has CNNH4+= 27 mg/L at first, using CZ-Na=13g/L and after 5 minutes, the concentration of ammonium in water was declined to 1mg/L, passed the Vietnamese standard for ground water (QCVN 09:2015- MT/BTNMT). The treating coefficient is 96.30%, the adsorption capacity is 2.07 mg N-NH4 +/1g ZNa. The loaded Z-Na was regenerated using 2g/L NaOH solution, the ammonium recovery ratio exceeded 92%. This means the reuse of Z-Na for ammonium adsorption is very high. The results of the experiment with groundwater samples in Phu Xuyen district, Ha Noi have a concentration of 53 mg/L. In conclusion, Z-Na material is perfectly fit for purpose of treating ammonium in ground water because of it low price, safety, easily to imitate and high efficiency.Xử lí ô nhiễm amoni trong nước ngầm bằng vật liệu zeolite tự nhiên được biến tính bằng muối ăn (Z-Na) là một hướng nghiên cứu mới, được các nhà khoa học rất quan tâm. Kết quả thí nghiệm cho thấy, tại pH 6 thì hiệu quả xử lí amoni trong nước là tốt nhất. Hiệu quả xử lí amoni trong nước tăng rất nhanh trong 5 phút đầu tiên xử lý. Càng tăng nồng độ Z-Na thì hiệu quả xử lí amoni càng cao. Với dung dịch nước ban đầu có nồng độ amoni tính theo nitơ (N-NH4 +) nhỏ hơn 27 mg/L và nồng độ vật liệu Z-Na sử dụng là 13g/L thì nước sau xử lí có nồng độ nhỏ hơn 1mg N-NH4 +/L, đạt QCVN 09-MT:2015/BTNMT, hiệu suất xử lí đạt 96,30%, dung lượng hấp phụ cực đại đạt 2,07 mg NNH4 +/1g Z-Na. Vật liệu Z-Na sau khi xử lý được nghiên cứu giải hấp bằng dung dịch NaOH với nồng độ 2g/L cho thấy hiệu quả giải hấp đạt 92% lượng amoni được hấp phụ. Điều này chứng tỏ khả năng tái sử dụng của vật liệu Z-Na cho hấp phụ amoni là khá cao. Kết quả nghiên cứu đã được thử nghiệm xử lý với mẫu nước ngầm tại huyện Phú Xuyên, Hà Nội có nồng độ N-NH4 + là 53 mg/L. Vì vậy, vật liệu Z-Na hoàn toàn có thể ứng dụng vào thực tiễn để xử lý amoni trong nước ngầm rất an toàn, dễ thực hiện và hiệu quả cao

LAND USE CHANGE AND RELATED PROBLEMS UNDER URBANIZATION IN SUBURBAN AREA OF HANOI CITY (A CASE STUDY OF HOANG LIET COMMUNE, THANH TRI DISTRICT)

Joint Research on Environmental Science and Technology for the Eart

ẢNH HƯỞNG CỦA NƯỚC BIỂN DÂNG ĐẾN THỦY TRIỀU KHU VỰC BIỂN MIỀN TRUNG CỦA VIỆT NAM

The tide is one of the most important phenomena in the ocean. In the world as well as in Vietnam, the tide was studied very early and great achievements have been recorded. However, under the impact of climate change and sea level rise, the local - to - regional - scale changes will cause significant changes in the coastal system. This paper gives some results of research on the tidal changes in the central region of Vietnam by using the hydrodynamic model and data analysing model. The simulation results of the tide in the central coast of Vietnam show that the tide can change both in the amplitude and phase distribution of the tidal constituents as M2, S2, K1 and O1. Specifically, the results of the average values of M2 are 0.1 m and 10.20; for S2 are 0.12 m and 12.50; for K1 are 0.2 m and 17.20; for O1 are 0.21 m and 20.20. Some results of this study showed that the most important contribution to the change of the tide in the region is the change of topography and the submerged areas.Thủy triều là một trong những hiện tượng quan trọng nhất trong đại dương. Trên thế giới cũng như ở Việt Nam, thủy triều được nghiên cứu từ rất sớm và đã đạt được nhiều thành tựu to lớn. Tuy nhiên, dưới tác động của biến đổi khí hậu và nước biển dâng, các quá trình có quy mô khu vực mang tính chất địa phương sẽ gây ra những thay đổi quan trọng trong các hệ thống ven biển. Bài báo này đưa ra một số kết quả nghiên cứu sự biến đổi của thủy triều trong khu vực biển miền Trung của Việt Nam. Nghiên cứu sử dụng phương pháp mô hình và phân tích điều hòa. Các kết quả mô phỏng về thủy triều trong khu vực biển miền Trung của Việt Nam cho thấy rằng thủy triều có sự biến đổi cả về biên độ và pha của các phân triều chính như M2, S2, K1 và O1. Cụ thể, kết quả giá trị trung bình đối với M2 là 0,1 m và 10,20; đối với S2 là 0,12 m và 12,50; đối với K1 là 0,2 m và 17,20; đối với O1 là 0,21 m và 20,20. Một số kết quả nghiên cứu này đã cho thấy rằng những đóng góp quan trọng nhất vào sự thay đổi của thủy triều trong khu vực là sự thay đổi địa hình và diện tích của thủy vực

THE INFRASTRUCTURE AND ENVIRONMENT IN THE OLD TENEMENTS IN HANOI

Joint Research on Environmental Science and Technology for the Eart

LAKESCAPE UNDER URBAN DEVELOPMENT IN DONG DA DISTRICT, HANOI CITY

Joint Research on Environmental Science and Technology for the Eart

Study on the model to determine riverbed scour and the influence of bridge construction on riverbed deformation

River geomorphic features can dramatically change over time. It is undoubtedly the most dynamic geomorphic system that engineers have to manage in the design and maintenance of bridges. In the event of major floods, significant changes can take place within a short period of time. In contrast to rivers which are dynamic, bridges generally do not move except in accordance with planned structural deflections caused by anticipated static and dynamic loading. The stability and safety of bridges can be jeopardized in several ways as a result of riverbed channel changes, being the removal of bed material in the vicinity of bridge foundations (as a result of local scouring phenomenon) the most common cause of several bridge collapses worldwide. Due to the complex nature of the fluid flow, there are still many uncertainties that affect the design process of bridge piers. Therefore, different approaches have been used comprising empirical formulations, experimental studies, sophisticated numerical simulations, and, whenever possible, underwater survey activities as a manner of monitoring the scouring process at bridge piers founded in alluvial/movable riverbeds. Therefore, the present study analyses the local scour phenomenon around the bridge piers of an intervened Vietnam bridge – Doan Hung bridge, by using different monitoring inspection surveys over a period of time. Research results will clarify the influence of bridge piers’ design and construction on movable beds, indicate future predictions to monitor and control the severity of the scouring process, and propose management measures for the safety of bridge infrastructures.This work was supported by the Project PTDC-ECI-EGC-5177-2020 (POSEIDON project), funded by national funds through the FCT – Portuguese Foundation for Science and Technology. This work was partly financed by FCT / MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020 and Vingroup and supported by Innovation Foundation (VINIF) under project code VINIF.2021.DA00192. Tran Quang Minh was supported by the doctoral Grant reference PRT/BD/154268/2022 financed by Portuguese Foundation for Science and Technology (FCT), under MIT Portugal Program (2022 MPP2030-FCT). Hélder S. Sousa acknowledges the funding by FCT through the Scientific Employment Stimulus - 4th Edition

Structural assessment based on vibration measurement test combined with an artificial neural network for the steel truss bridge

Damage assessment is one of the most crucial issues for bridge engineers during the operational and maintenance phase, especially for existing steel bridges. Among several methodologies, the vibration measurement test is a typical approach, in which the natural frequency variation of the structure is monitored to detect the existence of damage. However, locating and quantifying the damage is still a big challenge for this method, due to the required human resources and logistics involved. In this regard, an artificial intelligence (AI)-based approach seems to be a potential way of overcoming such obstacles. This study deployed a comprehensive campaign to determine all the dynamic parameters of a predamaged steel truss bridge structure. Based on the results for mode shape, natural frequency, and damping ratio, a finite element model (FEM) was created and updated. The artificial intelligence network’s input data from the damage cases were then analysed and evaluated. The trained artificial neural network model was curated and evaluated to confirm the approach’s feasibility. During the actual operational stage of the steel truss bridge, this damage assessment system showed good performance, in terms of monitoring the structural behaviour of the bridge under some unexpected accidents.This research was funded by FCT/MCTES through national funds (PIDDAC) from the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under the reference UIDB/04029/2020, and from the Associate Laboratory Advanced Production and Intelligent Systems ARISE, under the reference LA/P/0112/2020, as well as financial support of the project research “B2022-GHA-03” from the Ministry of Education and Training. And The APC was funded by ANI (“Agência Nacional de Inovação”) through the financial support given to the R&D Project “GOA Bridge Management System—Bridge Intelligence”, with reference POCI-01-0247-FEDER069642, which was cofinanced by the European Regional Development Fund (FEDER) through the Operational Competitiveness and Internationalisation Program (POCI)