STUDYING AND USING MACRO-INVERTEBRATES FOR ASSESSING THE QUALITY OF WATER ENVIRONMENT IN NHUE RIVER

Joint Research on Environmental Science and Technology for the Eart

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

Fish distribution in the Ba Che and Tien Yen rivers

The ichthyo-fauna in the Ba Che and Tien Yen rivers, northern Vietnam is highly diverse, with a total of 245 species determined. However, data on the distribution of fish species are not sufficiently provided for the whole area. This study was conducted from 2008 to 2011 at 27 stations from the Ba Che and Tien Yen river basins to determine the distribution of fish species according to different sections of the rivers, water bodies, seasons, and salinity levels. The results show that fish species are distributed mainly in the river (with 210 species), concentrated in the downstream area (with 213 species). Fishes are mainly collected in the dry season when the salinity level of river is high, due to seawater intrusion which also brings in 160 species of marine fish. This shows that fish distribution in the research areas is mainly dominated by the presence of marine species. While for freshwater fish, it is clearly affected by the mountainous features. Apart from the common characteristics sharing between the two river basins, but the number of both freshwater and marine fish species in the Tien Yen river are larger than those of Ba Che river, which is related to fresh water surface, river morphology, the width and location of the estuary to the sea. The downstream area is home to the fish species recorded in the Red Data Book of Vietnam and the complementary species for Vietnam, while the middle and upstream of the rivers may offer a high potential of biodiversity, with many possibly new species for science. These are important data for the conservation and sustainable development of fish resources in the Ba Che and Tien Yen river basins.

One-pot preparation of alumina-modified polysulfone-graphene oxide nanocomposite membrane for separation of emulsion-oil from wastewater

In recent years, polysulfone-based nanocomposite membranes have been widely used for contaminated water treatment because they comprise properties such as high thermal stability and chemical resistance. In this study, a polysulfone (PSf) nanocomposite membrane was fabricated using the wet-phase inversion method with the fusion of graphene oxide (GO) and alumina (Al2O3) nanoparticles. We also showed that GO-Al2O3 nanoparticles were synthesised successfully by using a one-pot hydrothermal method. The nanocomposite membranes were characterised by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherms, energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), and water contact angle. The loading of GO and Al2O3 was investigated to improve the hydrophilic and oil rejection of the matrix membrane. It was shown that by using 1.5 wt.% GO-Al2O3 loaded in polysulfone, ~74% volume of oil was separated from the oil/water emulsion at 0.87 bar and 30 min. This figure was higher than that of the process using the unmodified membrane (PSf/GO) at the same conditions, in which only ~60% volume of oil was separated. The pH, oil/water emulsion concentration, separation time, and irreversible fouling coefficient (FRw) were also investigated. The obtained results suggested that the GO-Al2O3 nanoparticles loaded in the polysulfone membrane might have potential use in oily wastewater treatment applications

Designing a novel heterostructure AgInS₂@MIL-101(Cr) photocatalyst from PET plastic waste for tetracycline degradation

Semiconductor-containing porous materials with a well-defined structure could be unique scaffolds for carrying out selective organic transformations driven by visible light. We herein introduce for the first time a heterostructure of silver indium sulfide (AgInS(2)) ternary chalcogenide and a highly porous MIL-101(Cr) metal–organic framework (MOF) synthesised from polyethylene terephthalate plastic waste. Our results demonstrate that AgInS(2) nanoparticles were uniformly attached to each lattice plane of the octahedral MIL-101(Cr) structure, resulting in a nanocomposite with a high distribution of semiconductors in a porous media. We also demonstrate that the nanocomposite with up to 40% of AgInS(2) doping exhibited excellent catalytic activity for tetracycline degradation under visible light irradiation (∼99% tetracycline degraded after 4 h) and predominantly maintained its performance after five cycles. These results could promote a new material circularity pathway to develop new semiconductors that can be used to protect water from further pollution

NOWJ1@ALQAC 2023: Enhancing Legal Task Performance with Classic Statistical Models and Pre-trained Language Models

This paper describes the NOWJ1 Team's approach for the Automated Legal Question Answering Competition (ALQAC) 2023, which focuses on enhancing legal task performance by integrating classical statistical models and Pre-trained Language Models (PLMs). For the document retrieval task, we implement a pre-processing step to overcome input limitations and apply learning-to-rank methods to consolidate features from various models. The question-answering task is split into two sub-tasks: sentence classification and answer extraction. We incorporate state-of-the-art models to develop distinct systems for each sub-task, utilizing both classic statistical models and pre-trained Language Models. Experimental results demonstrate the promising potential of our proposed methodology in the competition.Comment: ISAILD@KSE 202