scholarly journals The toxicity of lead to the freshwater microalgae Scenedesmus and the water flea Daphnia carinata

2021 ◽  
Vol 18 (4) ◽  
pp. 755-761
Author(s):  
Dinh Hoang Dang Khoa ◽  
Pham Thi Thu Hang ◽  
Pham Thi Hoanh ◽  
Le Phi Nga
Keyword(s):  
Anthropogenic Activities ◽  
Chemical Characterization ◽  
High Sensitivity ◽  
Toxicity Tests ◽  
Freshwater Algae ◽  
Water Flea ◽  
Freshwater Microalgae ◽  
Daphnia Carinata ◽  
Living Organisms ◽  
Physical And Chemical

Sai Gon river is the important source for water supply in Ho Chi Minh City. However, its water quality is degrading gradually due to rapid population growth, increasing of urbanization and industrialization. The river is continuously loaded with xenobiotics released by anthropogenic activities. Among pollutants, heavy metals are considered as the most toxic elements to aquatic living organisms and human health. The aim of this study is to assess the sensibility of freshwater microalgae Scenedesmus and water flea Daphnia carinata, two fresh water species from Viet Nam to lead (Pb). After physical and chemical characterization, field water samples from the upstream of Sai Gon River was used as dilution water in toxicity tests. With water flea D. carinata, the EC50 value of 48h immobilization experiment was 121.64 µg/L for Pb. Growth inhibition of the algae cells was determined following exposure for 96 h, and EC50 values of Pb was 14,767.9 µg/L. The results showed that Pb was highly toxic to D. carinata, and harmful to freshwater algae Scenedesmus. Based on the observed high sensitivity with Pb, D. carinata is a potential bioindicator for the assessment of Pb pollution in Sai Gon river. While lead-tolerance algae Scenedesmus calls for further investigation on metal uptake capacity and utilization in Pb contaminated water treatment

scholarly journals Copper Toxicity to Tropical Water Flea Daphnia carinata and Freshwater Micro-algae Scenedesmus

2020 ◽  
Vol 9 (4) ◽  
pp. 1
Author(s):  
Khoa Dinh Hoang Dang ◽  
Thi Thu Hang Pham ◽  
Ngoc Tu Anh Pham ◽  
Hien Minh Tam Le ◽  
Tran Thi Yen Nhi ◽  
...  
Keyword(s):  
Fresh Water ◽  
Anthropogenic Activities ◽  
Copper Toxicity ◽  
Chemical Characterization ◽  
Toxicity Tests ◽  
Eastern Region ◽  
Freshwater Algae ◽  
Water Flea ◽  
Freshwater Microalgae ◽  
Daphnia Carinata

Sai Gon river is one most the most important river of South-eastern region of Vietnam by providing water resources and others vital natural services for millions of people in this area. In recent years, proportion with the sharply increasing of human activities in industry and agriculture, the river is continuously loaded with xenobiotics released by anthropogenic activities. Among pollutants, heavy metals are considered as the most toxic elements to aquatic living organisms and human health. The aim of this study is to assess the sensibility of freshwater microalgae Scenedesmus and water flea Daphnia carinata, two fresh water species from Vietnam to copper (Cu). After physical and chemical characterization, field water samples from upstream Sai Gon River was used as dilution water in toxicity tests. With water flea D. carinata, the EC50 value of 48h immobilization experiment was 1.90 µg/L. Growth inhibition of the Scenedesmus algae cells was determined following exposure for 72 h, and EC50 values was 78.2 µg/L. The results showed that Cu is highly toxic to both species, and water flea D. carinata was more sensitive than freshwater algae Scenedesmus. Based on the observed high sensitivity with Cu, both D. carinata and algae Scenedesmus are potential tools for the assessment of copper pollution in fresh water of Sai Gon river.

scholarly journals Synthesis and Characterization of Chitosan/Agar/SiO2 Nano Hydrogels For Removal of Amoxicillin and of Naproxen From Pharmaceutical Contaminants

2021 ◽  
Author(s):  
Omid Moradi ◽  
Samira Mhdavi ◽  
Sajjad Sedaghat
Keyword(s):  
Aqueous Media ◽  
Environmental Pollutants ◽  
Chemical Characterization ◽  
Solution Ph ◽  
Physical And Chemical Characterization ◽  
Pharmaceutical Contaminants ◽  
Living Organisms ◽  
Physical And Chemical

Abstract Today, environmental pollutants pose a threat to human societies and all living organisms, which is why they have attracted the attention of environmental researchers. In this study, in order to remove pharmaceutical contaminants Naproxen and Amoxicillin from aqueous media with SiO2 nanoparticles based on Agar and Chitosan was investigated. The study of structural properties, physical and chemical characterization of synthesized nanocomposite was investigated by FTIR, XRD, TEM, FE-SEM, DLS and EDX analyzes. In addition, the role of parameters affecting the removal of pharmaceutical contaminants such as solution pH, contact time, contaminant concentration and temperature were studied. Nanocomposites prepared from Agar and Chitosan showed good performance in absorbing naproxen and amoxicillin. According to the studies performed to remove naproxen, the max adsorption efficiency was obtained at a concentration of 20 mg/l with an absorbent dose of 0.05 g and a pH of 8 and at an optimum temperature of 25 °C and 99% in 15 min. Also, for amoxicillin with nanocomposite prepared with an initial concentration of 20 mg/l and an adsorbent dose of 0.05 g, a time of 10 min, a temperature of 25 °C and a pH of 8, the max removal efficiency of 91.15% was obtained.

scholarly journals Toxicity and Benefits of Urban Stabilized Sludge Intended for Agriculture Use

2020 ◽  
Vol 71 (7) ◽  
pp. 365-378
Author(s):  
Ion-Viorel Patroescu ◽  
Stefania Gheorghe ◽  
Ioana Alexandra Ionescu ◽  
Ionut Cristea ◽  
Irina Eugenia Lucaciu ◽  
...  
Keyword(s):  
Organic Fertilizer ◽  
Laboratory Data ◽  
Monitoring Program ◽  
Chemical Characterization ◽  
Inhibitory Effect ◽  
Lepidium Sativum ◽  
Sludge Disposal ◽  
Agriculture Soil ◽  
Living Organisms ◽  
Physical And Chemical

Sludge reuse is one of the main challenges of waste management and an action with environmentally consequences that must be kept under control. The progress of civilization leaded to the globally increase of sludge production. WWTPs treatment technologies, sludge disposal/recovery and also quality control and toxicological involvements became parts of strategical actions at international level. The main disposal strategies for sludge management include agriculture or landscaping purposes, or final disposal. The accepted international policy is sludge application as organic fertilizer in agriculture. In this context, the research paper presents laboratory data used in decisional actions for the sludge land disposal. The study covers physical and chemical characterization of sludge resulted from Focsani WWTP, agriculture soil collected from around of Focsani WWTP and their leachates in compliance with national norms. In addition, the toxic effects on soil organisms (plants) were evaluated. Generally, soil and sludge quality meet the normed criteria for minimizing the potential impact on the environment. The leachate experiments showed the non-hazardous character on the soil properties of groundwater, the predicted impact being insignificant for the tested sludge / soil chemical composition. Ecotoxicological assessment of stabilized sludge showed inhibitory effects in the range of 25% to 100% on seed germination and root growth of plants Sorghum sacharatum, Sinapis alba and Lepidium sativum. In the range of 1% or 5% no significant inhibitory effect of sludge on plants growth was observed. Sorghum sacharatum showed the best growth, but there were no relevant differences between species. A saftey dose of 5% sludge mixed with agriculture soil (250 tonnes per hectare) was established. A monitoring program of sludge / soil quality and also ecotoxic evaluation was recomanded for the saftey of crops growth and health of living organisms including humans.

Antibacterial and Anti-Biofilm Biosynthesised Silver and Gold Nanoparticles for Medical Applications: Mechanism of Action, Toxicity and Current Status

2020 ◽  
Vol 17 (2) ◽  
pp. 88-100 ◽  
Author(s):  
Sundos Suleman Ismail Abdalla ◽  
Haliza Katas ◽  
Fazren Azmi ◽  
Mohd Fauzi Mh Busra
Keyword(s):  
Gold Nanoparticles ◽  
Synthesis Method ◽  
Chemical Characterization ◽  
Current Status ◽  
Silver And Gold Nanoparticles ◽  
Physical And Chemical Characterization ◽  
Biosynthesized Agnps ◽  
Physical And Chemical ◽  
Insight Into ◽  
Bio Synthesis

Fast progress in nanoscience and nanotechnology has contributed to the way in which people diagnose, combat, and overcome various diseases differently from the conventional methods. Metal nanoparticles, mainly silver and gold nanoparticles (AgNPs and AuNPs, respectively), are currently developed for many applications in the medical and pharmaceutical area including as antibacterial, antibiofilm as well as anti-leshmanial agents, drug delivery systems, diagnostics tools, as well as being included in personal care products and cosmetics. In this review, the preparation of AgNPs and AuNPs using different methods is discussed, particularly the green or bio- synthesis method as well as common methods used for their physical and chemical characterization. In addition, the mechanisms of the antimicrobial and anti-biofilm activity of AgNPs and AuNPs are discussed, along with the toxicity of both nanoparticles. The review will provide insight into the potential of biosynthesized AgNPs and AuNPs as antimicrobial nanomaterial agents for future use.

scholarly journals Physical and Chemical Characterization of an Oyster Hemagglutinin

1969 ◽  
Vol 244 (15) ◽  
pp. 4128-4135
Author(s):  
R T Acton ◽  
J C Bennett ◽  
E E Evans ◽  
R E Schrohenloher
Keyword(s):  
Chemical Characterization ◽  
Physical And Chemical Characterization ◽  
Physical And Chemical

scholarly journals Striking forest revival at the end of the Roman Period in north-western Europe

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
C. Lambert ◽  
A. Penaud ◽  
M. Vidal ◽  
C. Gandini ◽  
L. Labeyrie ◽  
...  
Keyword(s):  
North Atlantic ◽  
Western Europe ◽  
Anthropogenic Activities ◽  
Sedimentary Environment ◽  
Pollen Grains ◽  
Roman Period ◽  
Freshwater Microalgae ◽  
Environmental Signals ◽  
The North ◽  
North Western

AbstractThe Holocene period (last 11,700 years BP) has been marked by significant climate variability over decadal to millennial timescales. The underlying mechanisms are still being debated, despite ocean–atmosphere–land connections put forward in many paleo-studies. Among the main drivers, involving a cluster of spectral signatures and shaping the climate of north-western Europe, are solar activity, the North Atlantic Oscillation (NAO) varying atmospheric regimes and North Atlantic oceanic gyre dynamics. Over the last 2500 years BP, paleo-environmental signals have been strongly affected by anthropogenic activities through deforestation and land use for crops, grazing, habitations, or access to resources. Palynological proxies (especially pollen grains and marine or freshwater microalgae) help to highlight such anthropogenic imprints over natural variability. Palynological analyses conducted in a macro-estuarine sedimentary environment of north-western France over the last 2500 years BP reveal a huge and atypical 300 year-long arboreal increase between 1700 and 1400 years BP (around 250 and 550 years AD) that we refer to as the ‘1.7–1.4 ka Arboreal Pollen rise event’ or ‘1.7–1.4 ka AP event’. Interestingly, the climatic 1700–1200 years BP interval coincides with evidence for the withdrawal of coastal societies in Brittany (NW France), in an unfavourable socio-economic context. We suggest that subpolar North Atlantic gyre strengthening and related increasing recurrence of storminess extremes may have affected long-term coastal anthropogenic trajectories resulting in a local collapse of coastal agrarian societies, partly forced by climatic degradation at the end of the Roman Period.

Miscible blend polyethersulfone/polyimide asymmetric membrane crosslinked with 1,3-diaminopropane for hydrogen separation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nur’ Adilah Abdul Nasir ◽  
Ameen Gabr Ahmed Alshaghdari ◽  
Mohd Usman Mohd Junaidi ◽  
Nur Awanis Hashim ◽  
Mohamad Fairus Rabuni ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Chemical Characterization ◽  
Gas Permeation ◽  
Separation Performance ◽  
Membrane Composition ◽  
Asymmetric Membrane ◽  
Wet Phase Inversion ◽  
Pair Performance ◽  
Improved Performance ◽  
Physical And Chemical

Abstract Efficient purification technology is crucial to fully utilize hydrogen (H2) as the next generation fuel source. Polyimide (PI) membranes have been intensively applied for H2 purification but its current separation performance of neat PI membranes is insufficient to fulfill industrial demand. This study employs blending and crosslinking modification simultaneously to enhance the separation efficiency of a membrane. Polyethersulfone (PES) and Co-PI (P84) blend asymmetric membranes have been prepared via dry–wet phase inversion with three different ratios. Pure H2 and carbon dioxide (CO2) gas permeation are conducted on the polymer blends to find the best formulation for membrane composition for effective H2 purification. Next, the membrane with the best blending ratio is chemically modified using 1,3-diaminopropane (PDA) with variable reaction time. Physical and chemical characterization of all membranes was evaluated using field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR). Upon 15 min modification, the polymer membrane achieved an improvement on H2/CO2 selectivity by 88.9%. Moreover, similar membrane has demonstrated the best performance as it has surpassed Robeson’s upper bound curve for H2/CO2 gas pair performance. Therefore, this finding is significant towards the development of H2-selective membranes with improved performance.

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