Silver-doped MIL-101(Cr) for rapid and effective capture of iodide in water environment: exploration on adsorption mechanism

2021 ◽  
Author(s):  
Jie Wan ◽  
Ye Li ◽  
Yumeng Jiang ◽  
Luyao Lin ◽  
Yixin Yin
Keyword(s):  
Adsorption Mechanism ◽  
Water Environment ◽  
Environment Exploration

Sorption of Tetracycline Antibiotics from Water

2013 ◽  
Vol 316-317 ◽  
pp. 641-644
Author(s):  
Hua Xiao ◽  
Man Yu ◽  
Wen Hao An ◽  
Yu Xin Xu ◽  
Xiao Yang Chen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Veterinary Medicine ◽  
Adsorption Mechanism ◽  
Surface Complexation ◽  
Water Environment ◽  
Model Fit ◽  
Exchange Cation ◽  
Tetracycline Antibiotics ◽  
Adsorption Mechanisms ◽  
Pseudo Second Order

Antibiotics are used in large amounts as human and veterinary medicine. Due to their use pattern, they possess a potential for reaching the water environment. In recent years great amount of evidence showed that tetracycline antibiotics were frequently detected in aquatic environment. In this paper, the literature on adsorption of tetracyclines (TCs) were reviewed and summarized. Adsorption kinetics, adsorption isotherm, and adsorption mechanism were discussed. The pseudo-second-order kinetics model fit the experimental data best in most cases of adsorption of TCs. Sorption of TCs followed Freundlich or Langmuir isotherm well in all cases. At last, main adsorption mechanisms such as cation exchange, cation bridging at surfaces, surface complexation, and hydrogen bonding could be suggested based on analysis by XRD, FTIR, NMR, HPLC, LC-MS, etc.

scholarly journals Simple Urea Immersion Enhanced Removal of Tetracycline from Water by Polystyrene Microspheres

2018 ◽  
Vol 15 (7) ◽  
pp. 1524
Author(s):  
Junjun Ma ◽  
Bing Li ◽  
Lincheng Zhou ◽  
Yin Zhu ◽  
Ji Li ◽  
...  
Keyword(s):  
Surface Modification ◽  
Adsorption Mechanism ◽  
Water Environment ◽  
Order Rate Constant ◽  
Maximum Adsorption Capacity ◽  
Polystyrene Microspheres ◽  
Multilayer Adsorption ◽  
First Order ◽  
Adsorption Capacities ◽  
Effective Removal

Antibiotics pose potential ecological risks in the water environment, necessitating their effective removal by reliable technologies. Adsorption is a conventional process to remove such chemicals from water without byproducts. However, finding cheap adsorbents with satisfactory performance is still a challenge. In this study, polystyrene microspheres (PSM) were enhanced to adsorb tetracycline by surface modification. Simple urea immersion was used to prepare urea-immersed PSM (UPSM), of which surface groups were characterized by instruments to confirm the effect of immersion. Tetracycline hydrochloride (TC) and doxycycline (DC) were used as typical adsorbates. The adsorptive isotherms were interpreted by Langmuir, Freundlich, and Tempkin models. After urea immersion, the maximum adsorption capacity of UPSM at 293 K and pH 6.8 increased about 30% and 60%, achieving 460 mg/g for TC and 430 mg/g for DC. The kinetic data were fitted by first-order and second-order kinetics and Weber–Morris models. The first-order rate constant for TC adsorption on UPSM was 0.41 /h, and for DC was 0.33 /h. The cyclic urea immersion enabled multilayer adsorption, which increased the adsorption capacities of TC on UPSM by two to three times. The adsorption mechanism was possibly determined by the molecular interaction including π–π forces, cation-π bonding, and hydrogen bonding. The simple surface modification was helpful in enhancing the removal of antibiotics from wastewater with similar structures.

Adsorption mechanism of Cu(II) in water environment using chitosan-nano zero valent iron-activated carbon composite beads

2019 ◽  
Vol 145 ◽  
pp. 202-210 ◽  
Author(s):  
Md. Tajuddin Sikder ◽  
Ryo Kubota ◽  
Mahmuda Akter ◽  
Md. Mostafizur Rahman ◽  
Kaniz Fatima Binte Hossain ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Mechanism ◽  
Water Environment ◽  
Carbon Composite ◽  
Zero Valent Iron ◽  
Composite Beads ◽  
Nano Zero Valent Iron

Establishing an empirical equation for the relationship between total suspended solids and total phosphorus concentrations in the downstream Red river water

2020 ◽  
Vol 20 (3) ◽  
pp. 325-332
Author(s):  
Le Nhu Da ◽  
Le Thi Phuong Quynh ◽  
Phung Thi Xuan Binh ◽  
Duong Thi Thuy ◽  
Trinh Hoai Thu ◽  
...  
Keyword(s):  
Total Phosphorus ◽  
Suspended Solids ◽  
Empirical Relationship ◽  
Water Environment ◽  
Total Suspended Solids ◽  
River System ◽  
Red River ◽  
Reservoir Impoundment ◽  
Downstream Section ◽  
Reasonable Prediction

Recently, the Asian rivers have faced the strong reduction of riverine total suspended solids (TSS) flux due to numerous dam/reservoir impoundment. The Red river system is a typical example of the Southeast Asian rivers that has been strongly impacted by reservoir impoundment in both China and Vietnam, especially in the recent period. It is known that the reduction in total suspended solids may lead to the decrease of some associated elements, including nutrients (N, P, Si) which may affect coastal ecosystems. In this paper, we establish the empirical relationship between total suspended solids and total phosphorus concentrations in water environment of the Red river in its downstream section from Hanoi city to the Ba Lat estuary based on the sampling campaigns conducted in the dry and wet seasons in 2017, 2018 and 2019. The results show a clear relationship with significant coefficient between total suspended solids and total phosphorus in the downstream Red river. It is expressed by a simple equation y = 0.0226x0.3867 where x and y stand for total suspended solids and total phosphorus concentrations (mg/l) respectively with the r2 value of 0.757. This equation enables a reasonable prediction of total phosphorus concentrations of the downstream Red river when the observed data of total suspended solids concentrations are available. Thus, this work opens up the way for further studies on the calculation of the total phosphorus over longer timescales using daily available total suspended solids values.

DEVELOPMENT OF INTEGRATED MONITORING NETWORK FOR MEASURING SALINITY OF SEA WATER

2018 ◽  
pp. 18-26
Author(s):  
Sima Ajdar qizi Askerova
Keyword(s):  
Surface Waters ◽  
Sea Water ◽  
Water Environment ◽  
Monitoring Network ◽  
Monitoring Networks ◽  
The Caspian Sea ◽  
Integrated Monitoring ◽  
Ecological Control ◽  
Different Depths ◽  
Optimal Construction

Monitoring of sea water condition is one of major requirements for carrying out the reliable ecological control of water environment. Monitoring networks contain such elements as sea buoys, beacons, etc. and are designated for measuringvarious hydrophysical parameters, including salinity of sea water. Development of specialized network and a separate buoy system for measuring thesea water salinity at different depths makes it possible to determine major regularities of processes of pollution and self-recovery of the sea waters. The article describes the scientific and methodological basics for development of this specialized network and questions of its optimal construction. It is well-known that at a depth of 30-45 m of the Caspian Sea salinity decreases and then at a depth of 45-60 m salinity is fully recovered. The mentioned changes of salinity at the relatively upper layer of sea waters is of special interest for studying the effect of ocean-going processes on the climate forming in the Caspian area. In terms of informativeness of measurements of surface waters salinity, the most informative is a layer ata 30-60 m depth, where inversion and recovery of salinity take place. It is shown that in most informative subrange of measurements, i. e. at a depth of 30-60 m optimization of regime of measurements complex should be carried out in order to increase the effectiveness of held researches. It is shown that at a depth of 35-50 m choice of the optimum regime of measurements makes it possible to obtain the maximum amount of information.

CORRELATION OF MICROCYSTINS AND WATER ENVIRONMENT FACTORS IN MIYUN RESERVOIR OF BEIJING, CHINA

2011 ◽  
Vol 10 (6) ◽  
pp. 849-853 ◽  
Author(s):  
Guisen Du ◽  
Huimin Li ◽  
Yumei Wu ◽  
Dianwei Wu ◽  
Jingshi Wang
Keyword(s):  
Water Environment ◽  
Miyun Reservoir ◽  
Environment Factors ◽  
Beijing China

PERBANDINGAN METODE HOMOMORPHIC FILTERING DAN METODE CONTRAST STRECHING UNTUK PERBAIKAN KUALITAS CITRA UNDERWATER

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Adi Mora Lubis ◽  
Nelly Astuti Hasibuan ◽  
Imam Saputra
Keyword(s):  
Digital Image ◽  
Water Environment ◽  
Repair Process ◽  
Image Process ◽  
Two Dimensional ◽  
Two Dimensional Image ◽  
Underwater Image ◽  
Homomorphic Filtering ◽  
Contrast Stretching

Digital imagery is a two-dimensional image process through a digital computer that is used to manipulate and modify images in various ways. Photos are examples of two-dimensional images that can be processed easily. Each photo in the form of a digital image can be processed through a specific software. In the water environment, the light factor greatly influences the results of the quality of the image obtained. With the deepening of underwater shooting, the results obtained will be the darker the quality of the underwater image. . uneven lighting and bluish tones. One of the factors that influence the recognition results in pattern recognition is the quality of the image that is inputted. The image acquired from the source does not always have good quality. The process of repairing digital images that experience interference in lighting. The lighting repair process uses homomorphic filtering and uses contrast striching and will compare the quality of both methods and test to prove the results of image quality between homomorphic filtering and contrast streching. Until later the results of both methods can be seen which is better. homomorphic filtering and contrast stretching can produce image improvements with pretty good performance.Keywords: Digital Image, Underwater Image, Homomorphic Filtering, Contrast Streching, Matlab R2010a

IMPLEMENTASI METODE RETINEX UNTUK MENINGKATKAN KUALITAS CITRA UNDERWATER

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Bainun Harahap
Keyword(s):  
Water Environment ◽  
Repair Process ◽  
Image Process ◽  
Two Dimensional ◽  
Two Dimensional Image ◽  
Underwater Image ◽  
Object Search ◽  
Image Improvement ◽  
Underwater Object

Digital imagery is a two-dimensional image process through a digital computer that is used to manipulate and modify images in various ways. Photos are examples of two-dimensional images that can be processed easily. Each photo in the form of a digital image can be processed through certain software devices. In the water environment, light factors greatly influence the results of image quality obtained. With the deepening of underwater shooting, the results obtained will be the darker the quality of the underwater image. Underwater imagery is widely used as an object in various activities such as underwater habitat mapping, underwater environment monitoring, underwater object search. Uneven lighting and colors that tend to be bluish and runny. One of the factors that influence the recognition results in pattern recognition is the quality of the image that is inputted. The image acquired from the source does not always have good quality. The process of improvement in digital images that experience interference in lighting and exposure to sunlight. The lighting repair process uses the retinex method and will compare the quality of the two methods later. Until later the results of both methods can be seen which is better. Retinex method can produce image improvement with high performance.Keywords: Digital Cintra, Underwater, Matlab Retinex Method

Environmental significance of atrazine in aqueous systems and its removal by biological processes: an overview

2013 ◽  
Vol 8 (2) ◽  
pp. 159-178 ◽  
Keyword(s):  
Drinking Water ◽  
Ground Water ◽  
Water Environment ◽  
Biological Processes ◽  
Biological Degradation ◽  
Environmental Significance ◽  
Carbon And Nitrogen ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Living Organisms

Atrazine, a chlorinated s-triazine group of herbicide is one of the most widely used pesticides in the World. Due to its extensive use, long half-life and various toxic properties, it has very high environmental significance. Up to 22 mg l-1 of atrazine was found in ground water whereas permissible limit of atrazine is in ppb level in drinking water. As per Indian standard there should not be any pesticide present in drinking water. Among many other treatment processes available, Incineration, adsorption, chemical treatment, phytoremediation and biodegradation are the most commonly used ones. Biological degradation of atrazine depends upon various factors like the operating environment, external carbon and nitrogen sources, carbon/ nitrogen ratio (C/N), water content and the bacterial strain. Although, general atrazine degradation pathways are available, the specific pathways in specific conditions are not yet clearly defined. In this paper extensive review has been made on the occurrence of atrazine in surface and ground water bodies, probable sources and causes of its occurrence in water environment, the toxicity of atrazine on various living organisms and its removal by biological processes.

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