Parathion degradation and toxicity reduction in solar photocatalysis and photolysis

2006 ◽  
Vol 53 (3) ◽  
pp. 1-8 ◽  
Author(s):  
K.-D. Zoh ◽  
T.-S. Kim ◽  
J.-G. Kim ◽  
K. Choi ◽  
S.-M. Yi
Keyword(s):  
Acute Toxicity ◽  
Photocatalytic Degradation ◽  
Toxicity Test ◽  
Methyl Parathion ◽  
Vibrio Fischeri ◽  
Acute Toxicity Test ◽  
Solar Photocatalysis ◽  
Toxicity Reduction ◽  
Solar Photolysis ◽  
Microtox Test

The solar photocatalytic degradation of methyl parathion was investigated using a circulating TiO2/solar light reactor. Under solar photocatalysis condition, parathion was more effectively degraded than solar photolysis and TiO2-only conditions. With solar photocatalysis, 20 mg/L of parathion was completely degraded within 60 min with a TOC decrease of 63% after 150 min. The main ionic byproducts during photocatalysis recovered from parathion degradation were mainly as NO3−, NO2− and NH4+, 80% of the sulphur as SO42−, and 5% of phosphorus as PO43−. The organic intermediates 4-nitrophenol and methyl paraoxon were also identified, and these were further degraded in solar photocatalytic condition. Two different bioassays (Vibrio fischeri and Daphnia magna) were used to test the acute toxicity of solutions treated by solar photocatalysis and photolysis. The Microtox test using V. fischeri showed that the toxicity expressed as EC50 (%) value increased from 5.5% to >82% in solar photocatalysis, indicating that the treated solution is non-toxic, but only increased from 4.9 to 20.5% after 150 min in solar photolysis. The acute toxicity test using D. magna showed that EC50 (%) increased from 0.05 to 1.08% under solar photocatalysis, but only increased to 0.12% after 150 min with solar photolysis, indicating the solution is still toxic. The pattern of toxicity reduction parallels the decrease in TOC and the parathion concentrations.

Degradation of parathion and the reduction of acute toxicity in TiO2 photocatalysis

2005 ◽  
Vol 52 (8) ◽  
pp. 45-52 ◽  
Author(s):  
K.D. Zoh ◽  
T.S. Kim ◽  
J.G. Kim ◽  
K.H. Choi
Keyword(s):  
Solar System ◽  
Acute Toxicity ◽  
Photocatalytic Degradation ◽  
Methyl Parathion ◽  
Vibrio Fischeri ◽  
Experimental Results ◽  
Nitrogen Recovery ◽  
Contaminated Water ◽  
Tio2 Photocatalysis ◽  
Solar Reactor

Photocatalytic degradation of methyl parathion was done using a circulating TiO2/UV and TiO2/solar reactor. Indoor experimental results showed that, under the photocatalysis conditions, parathion was more effectively degraded than under the photolysis and TiO2 only conditions. Parathion (38μM) was completely degraded under photocatalysis within 90min, and more than 80% TOC decrease after 150 minutes. The main ionic byproducts during the photocatalysis were measured, and almost complete nitrogen recovery was achieved as mainly NO3− NO2−, and NH4+, and 80% of sulfur as recovered as SO42−. Organic intermediates such as nitrophenol and methyl paraoxon were also identified during the photocatalysis of parathion, and these were further degraded after 90 minutes. Microtox bioassay using Vibrio fischeri was used in evaluating the toxicity of solutions treated by photocatalysis and photolysis of parathion. The results showed that the acute toxicity expressed as EC50 almost reduced after 90min under the photocatalysis condition whereas only 40% reduction of toxicity as EC50 was achieved in photolysis condition. The outdoor results using a TiO2/solar system were similar to the TiO2 indoor system, indicating the possibility of applying TiO2/solar system for the treatment of parathion-contaminated water.

scholarly journals Mixture toxicity of zinc oxide nanoparticle and chemicals with different mode of action upon Vibrio fischeri

2020 ◽  
Author(s):  
xiaoming zou ◽  
Ligui Wu ◽  
Fen Chen ◽  
Xiaoyu Xiao ◽  
Lingling Rong ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Acute Toxicity ◽  
Mode Of Action ◽  
Toxicity Test ◽  
Vibrio Fischeri ◽  
Mixture Toxicity ◽  
Acute Toxicity Test ◽  
Zinc Oxide Nanoparticle ◽  
Oxide Nanoparticle ◽  
The Difference

Abstract Background: Zinc oxide nanoparticle (nZnO) and chemicals with different mode of action (MOA, i.e., narcotic and reactive) were frequently detected in the Yangtze River. Organisms are typically exposed to mixtures of nZnO and other chemicals rather than individual nZnO. Toxicity of nZnO is caused by the dissolution of Zn2+, which has been proved in the field of single toxicity. However, it is still unclear whether the released Zn2+ plays a critical role in the nZnO toxicity of nZnO-chemicals mixtures. In the present study, the binary mixture toxicity of nZnO/Zn2+ and chemicals with different MOA was investigated in acute (15 min) and chronic (12 h) toxicity test upon Vibrio fischeri (V. fischeri). The joint effects of nZnO and tested chemicals were explored. Moreover, two classic models, concentration addition (CA) and independent action (IA) were applied to predict the toxicity of mixtures. Results: The difference of toxicity unit (TU) values between the mixtures of Zn2+-chemicals with those of nZnO-chemicals was not significant (P> 0.05), not only in acute toxicity test but also in chronic toxicity test. The antagonistic or additive effects for nZnO-chemicals can be observed in most mixtures, with the TU values ranging from 0.75-1.77 and 0.47-2.45 in acute toxicity test and chronic test, respectively. We also observed that the prediction accuracy of CA and IA models was not very well in the mixtures where the difference between the toxicity ratios of the components was small (less than about 10), with the mean absolute percentage error (MAPE) values ranging from 0.14-0.67 for CA model and 0.17-0.51 for IA model, respectively.Conclusion: We found that the dissolved Zn2+ mainly accounted for the nZnO toxicity in the mixtures of nZnO-chemicals, and the joint effects of these mixtures were mostly antagonism and additivity. CA and IA models were unsuitable for predicting the mixture toxicity of nZnO-chemicals at their equitoxic ratios.

scholarly journals Mixture toxicity of zinc oxide nanoparticle and chemicals with different mode of action upon Vibrio fischeri

2020 ◽  
Author(s):  
Fen Chen ◽  
Ligui Wu ◽  
Xiaoyu Xiao ◽  
Lingling Rong ◽  
Mi Li ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Acute Toxicity ◽  
Mode Of Action ◽  
Toxicity Test ◽  
Vibrio Fischeri ◽  
Mixture Toxicity ◽  
Acute Toxicity Test ◽  
Zinc Oxide Nanoparticle ◽  
Oxide Nanoparticle ◽  
The Difference

Abstract Background: Zinc oxide nanoparticle ( n ZnO) and chemicals with different mode of action (MOA, i.e., narcotic and reactive) were frequently detected in the Yangtze River. Organisms are typically exposed to mixtures of n ZnO and other chemicals rather than individual n ZnO. Toxicity of n ZnO is caused by the dissolution of Zn 2+ , which has been proved in the field of single toxicity. However, it is still unclear whether the released Zn 2+ plays a critical role in the n ZnO toxicity of n ZnO-chemicals mixtures. In the present study, the binary mixture toxicity of n ZnO/Zn 2+ and chemicals with different MOA was investigated in acute (15 min) and chronic (12 h) toxicity test upon Vibrio fischeri ( V. fischeri ). The joint effects of n ZnO and tested chemicals were explored. Moreover, two classic models, concentration addition (CA) and independent action (IA) were applied to predict the toxicity of mixtures. Results: The difference of toxicity unit (TU) values between the mixtures of Zn 2+ -chemicals with those of n ZnO-chemicals was not significant ( P > 0.05), not only in acute toxicity test but also in chronic toxicity test. The antagonistic or additive effects for n ZnO-chemicals can be observed in most mixtures, with the TU values ranging from 0.75-1.77 and 0.47-2.45 in acute toxicity test and chronic test, respectively. We also observed that the prediction accuracy of CA and IA models was not very well in the mixtures where the difference between the toxicity ratios of the components was small (less than about 10), with the mean absolute percentage error (MAPE) values ranging from 0.14-0.67 for CA model and 0.17-0.51 for IA model, respectively. Conclusion: We found that the dissolved Zn 2+ mainly accounted for the n ZnO toxicity in the mixtures of n ZnO-chemicals, and the joint effects of these mixtures were mostly antagonism and additivity. CA and IA models were unsuitable for predicting the mixture toxicity of n ZnO-chemicals at their equitoxic ratios.

Effects of atrazine and alachlor on self-purification processes in receiving streams

1996 ◽  
Vol 33 (6) ◽  
pp. 181-187 ◽  
Author(s):  
Jana Zagorc-Koncan
Keyword(s):  
Adverse Effect ◽  
Acute Toxicity ◽  
Toxicity Test ◽  
Chronic Toxicity ◽  
Acute Toxicity Test ◽  
Organic Substances ◽  
Inhibiting Effect ◽  
Scenedesmus Subspicatus ◽  
Net Assimilation ◽  
Chlorophyll A Content

In recent years many waterways in Slovenia have been subjected to an increased loading with pesticides due to intensification of agriculture. The most widely used herbicides are atrazine and alachlor and they were detected in some rivers and even in ground water. Therefore the effects of atrazine and alachlor on selfpurification processes were investigated. The basic selfpurification processes studied were biodegradation of organic substances and photosynthesis and growth of algae. The inhibiting effect of pesticides on the process of biodegradation of organic pollutants was evaluated by the use of laboratory river model and mathematical modelling. The harmful impacts of pesticides on aquatic autotrophic organisms were assessed by measurement of net assimilation inhibition (24-h acute toxicity test) as well as growth inhibition - chlorophyll- a content (72-h chronic toxicity test) of algae Scenedesmus subspicatus. The results obtained demonstrate that atrazine and alachlor in concentrations found in our rivers have practically no effect on biodegrading heterotrophic organisms, while their adverse effect on algae is quite considerable.

scholarly journals Dying for change: A roadmap to refine the fish acute toxicity test after 40 years of applying a lethal endpoint

2021 ◽  
Vol 223 ◽  
pp. 112585
Author(s):  
Ioanna Katsiadaki ◽  
Tim Ellis ◽  
Linda Andersen ◽  
Philipp Antczak ◽  
Ellen Blaker ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Toxicity Test ◽  
Acute Toxicity Test

Ceriofast™: An acute toxicity test based onCeriodaphnia dubiafeeding behavior

1996 ◽  
Vol 15 (2) ◽  
pp. 123-125
Author(s):  
Gabriel Bitton ◽  
Kimberly Rhodes ◽  
Ben Koopman
Keyword(s):  
Acute Toxicity ◽  
Toxicity Test ◽  
Acute Toxicity Test

Study on the Safety of Mineral and Synthetic Oil Added Commonly Used Extreme Pressure Additives

2012 ◽  
Vol 430-432 ◽  
pp. 1386-1389
Author(s):  
Zhuo Jun Chen ◽  
Long Long Feng ◽  
Bao Liang Li ◽  
Jin Jin Yue ◽  
Ying Liang Wu ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Toxicity Test ◽  
Mineral Oil ◽  
Stimulation Test ◽  
Toxicity Tests ◽  
Acute Toxicity Test ◽  
Base Oil ◽  
Synthetic Oil ◽  
Four Levels ◽  
Oral Acute Toxicity

This article use the Sulphide Isobutene (T321), Five Sufides Dialkyl(RC2540) and Star of Phosphorus(P110) as the additives,Neopentyl Polyol Ester(NPE) and mineral oil N32 as base oil. Compound above additives and base oil for the four levels. A sample: adding 4% T321 additive in NPE. B sample: adding 4% T321 additive in N32. C sample: adding 4% RC2540 additive in NPE. D sample: adding RC2540, T321 and P110 additives in NPE (all is mass fraction). The oral acute toxicity test, eye mucous stimulation test, skin hypersensitive test, soaking tail toxicity tests were conducted in above samples. The test results show that. The mineral oil, it’s not only toxic then synthetic oil but also has a poor lubricating ability compare with the same percent additive in synthetic oil. In oral acute toxicity test, eye mucous stimulation test, skin hypersensitive test, soaking tail toxicity tests, Toxic reaction of mineral N32+4%wt Sulphide Isobutene (T321) obviously from other oil samples.

Acute toxicity test for the ethanolic extract of the white oyster mushroom

2020 ◽  
pp. 41-43
Author(s):  
S.B. Rahimah ◽  
Y. Kharisma ◽  
M.K. Dewi ◽  
J. Hartati ◽  
W. Maharani
Keyword(s):  
Acute Toxicity ◽  
Toxicity Test ◽  
Ethanolic Extract ◽  
Oyster Mushroom ◽  
Acute Toxicity Test

scholarly journals Evaluation on Toxicity Level of Terminalia catappa Leaves Extract on Selected Cyprinids under Different Bath Concentrations

2020 ◽  
Vol 43 (4) ◽  
Author(s):  
Emi Fazlina Hashim ◽  
Irence John ◽  
Intan Faraha A Ghani ◽  
Mohammad Noor Amal Azmai
Keyword(s):  
Acute Toxicity ◽  
Toxicity Test ◽  
Safety Margin ◽  
Probit Analysis ◽  
Time Interval ◽  
Acute Toxicity Test ◽  
High Concentration ◽  
Terminalia Catappa ◽  
Cyprinid Species ◽  
Goldfish Carassius Auratus

This study aimed to determine the lethal concentration (LC50) of Terminalia catappa leaves extract on three cyprinid species; carp (Cyprinus carpio), goldfish (Carassius auratus) and tiger barb (Puntigrus tetrazona) through the acute toxicity test. The leaves of T. catappa were extracted with methanol and prepared in various immersion concentrations (40, 80, 100, 150, 200, 250, 300, and 350 mg/L). These extracts were immersed in the aquarium and left for 24 h before performing the acute toxicity test. The water quality was also analyzed before and after adding the extract immersions into the aquarium. The acute toxicity test conducted for 96 h with 10 fishes of each cyprinid species (4.0-6.0 cm length) in 30 L water capacity aquarium. The mortality of each cyprinid species was recorded at 24 h time interval and LC50 of the extracts throughout 96 hours was determined through the probit analysis application. Specifically, the LC50 of T. catappa leaves extract were 349.89, 338.65 and 318.48 mg/L exhibited for carp, goldfish and tiger barb, respectively. A high concentration range of any plant-based extract has the potential to become toxic to particular fishes. Thus, it is an effort from this study to identify the safety margin of T. catappa leaves extract before its therapeutic values can be further manipulated and elucidated in aquaculture research.

Acute Toxicity Investigation of Landfill Leachates Treated with Fine Bubbles

2021 ◽  
Vol 41 ◽  
pp. 55-65
Author(s):  
Hikmat Kasmara ◽  
Desti Pratiwi ◽  
Sundoro Yoga Azhary ◽  
Eko Sulistyo ◽  
Camellia Panatarani ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Acute Toxicity ◽  
Toxicity Test ◽  
Waste Treatment ◽  
Probit Analysis ◽  
Acute Toxicity Test ◽  
Landfill Leachates ◽  
Leachate Treatment ◽  
Fine Bubble ◽  
Before And After

Landfill Leachates is one of the pollutants containing high organic matter and heavy metal which can cause toxic pollution to water due to less than optimal leachate processing. This study aims to introduce fine bubbles treatment to the leachate processing technology at the waste treatment facility at Sarimukti, West Java Indonesia. The toxicity test was conducted in the acute toxicity test and test for D. magna. The acute toxicity test was carried out using a static biological test according to APHA standards (1995). The LC50-48 hours ware calculates using the Finney Probit Analysis Software. The results showed that the effectiveness of Sarimukti TPA leachate treatment was 97.5% DO, 71% BOD, 86% TDS, and 74.8% turbidity. The XRF spectra on the leachate after fine bubble found a recovery of heavy metal elements such as Cr, Mn, Fe, Zn, Cu, Pb, As, and Sn. Based on the Minister of Environment and Forestry Regulation, the effectiveness of leachate processing has reached the safe standard limit for pH, mercury, cadmium parameters. The acute toxicity of leachate before and after treatment fine bubble was 14.516 ppm and 11.178 ppm. The acute toxicity of leachate is considered almost non-toxic.

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