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Antioxidants, Stabilizers, and Fire Retardants
Published in Nicholas P. Cheremisinoff, Hazardous Chemicals in the Polymer Industry, 2017
Waste Disposal Method: Incinerate in chemical incinerator equipped with an afterburner and scrubber. Follow all federal, state, and local regulations. Effluent Data-Bod: Aerobic sewage OECD coupled units test No. 303A: Average elimination measured by specific analysis was 45.2% of the initially measured concentration. Effluent Data-Cod: 2.38 G COD/G Irganox 1010. Sewage Bacterial Toxicity: Inhibitory concentration on respiration of aerobic waste water bacteria: IC20, IC50, IC80 > 100 ppm. Fish toxicity: Zebra Fish, LC50 96 H: > 100 ppm. Invertebrate Toxicity: Daphnia Magna, EC50 24 H: > 86 ppm.
Comparative Assessment of the Toxic Effects from Pulp Mill Effluents to Marine and Brackish Water Organisms
Published in Mark R. Servos, Kelly R. Munkittrick, John H. Carey, Glen J. Van Der Kraak, and PAPER MILL EFFLUENTS, 2020
B. Eklund, M. Linde, M. Tarkpea
According to the Microtox 15 min and the Nitocra acute tests, no toxicity could be detected after biological treatment of the effluents from the TCF process (Table 2). However, after the 30 min Microtox test a 20% reduction of the luminescence was noticed at 78.7% effluent. In the acute test with N. spinipes 10% of the animals died at 42.7% TCF effluent. The reproduction test with C. strictum was the most sensitive test for TCF effluent. A 50% effect on reproduction was already observed at 14.9%, before biological treatment. After treatment, toxicity was reduced to almost half and the EC50 value was 26.2%.
Abiotic Removal with Adsorption and Photocatalytic Reaction
Published in Jayant K. Singh, Nishith Verma, Aqueous Phase Adsorption, 2018
Robert Chang-Tang Chang, Bor-Yann Chen, Ke-Fu Zhou, Qiao-Jie Yu, Xiao-Dan Xie, Mridula P. Menon, Arun Kumar Subramani
As indicated in dose response curves, the half effect concentration (EC50) was calculated for the comparative assessment. The corresponding pseudo-half effect concentration of the photolysis and photocatalysis solution was denoted as EC50-UV and EC50-T/M. As revealed in Figure 8.14, three fitting curves for each TCs solution are almost overlapped. For the three antibiotics, the ranking of biotoxicity potency was EC50 < EC50-UV < EC50-T/M. Many studies reported a slight increase in the toxicity of TCs solution after degradation because of the higher toxicity of intermediate than other pollutants [53–56]. Therefore, EC50-UV value should be less than EC50 if the toxicity significantly augmented after the degradation, while the result of this study seemed to be opposite. That is to say, there was no intermediate with higher toxicity potency detected after treatment. The inconsistent result with previous studies was likely because of the different methods of testing toxicity. The experimental time of luminous bacteria used in previous studies might be short. Therefore, this toxicity potency should be measured in terms of acute toxicity rather than chronic toxicity prone to short-term inhibition increase toxicity, while long-term inspection of bacterial culture may show no inhibition [57]. The results indicate that sufficient defense mechanism to overcome inhibitory characteristics of such toxic intermediates could be effectively induced for resistance of long-term toxicity. At present, conventional treatment techniques, membrane treatment, oxidation, and adsorption have their own disadvantages. T/M catalysts exhibited a certain potential in the treatment of antibiotic bearing wastewater due to its excellent adsorption and photocatalytic performance. To have conclusive data for economic feasibility, more detailed exploration of treatment mechanism should be implemented prior to further scale-up for industrial applications. Tetracycline antibiotics was just as a typical example for the comparative assessments. Further studies on a myriad of antibiotics should be carried out with consideration of practicability for not only environmental friendliness, but also for ecological viability.
Advanced oxidation processes for waste water treatment: from laboratory-scale model water to on-site real waste water
Published in Environmental Technology, 2021
Julien G. Mahy, Cédric Wolfs, Christelle Vreuls, Stéphane Drot, Sophia Dircks, Andrea Boergers, Jochen Tuerk, Sophie Hermans, Stéphanie D. Lambert
In the case of laboratory-made water, the pollutant concentrations were evaluated with GC-MS and LC-MS/MS. As for the two types of industrial waste water, only the toxicity before and after treatment was evaluated. The toxicity test is based on the ISO 6341 standard [23]. During this experiment, Daphnia magna microcrustaceans were incubated for 24 h in the toxic water at different concentrations [5]. After 24 h of contact, the number of immobile microcrustaceans was counted [5]. This number was plotted against the concentration of the toxic water. From this, the relative concentration EC50, at which half of the microcrustaceans died, was found [5]. EC50 is expressed in the per cent of the initial concentration of the toxic water. The toxicity unit (TU) of the water is defined as TU = 100%/EC50. The water was considered toxic if 1 < TU < 10, and very toxic if TU > 10 [5].
Ni bioavailability in oat (Avena sativa) grown in naturally aged, Ni refinery-impacted agricultural soils
Published in Human and Ecological Risk Assessment: An International Journal, 2019
Yamini Gopalapillai, Tereza Dan, Beverley Hale
The present study was undertaken to understand Ni bioavailability in decades aged Ni in agricultural soils as a result of anthropogenic deposition, rather than as a result of experimental amendment. Most available toxicity models are based on the latter dataset. Such clarifications can provide essential information at the end of a tiered risk assessment approach, where the earlier conservative methods (e.g., CCME guidelines, PNEC calculator, etc.) may leave unanswered questions about the true risk of the soil in question. Accordingly, the present study aims to validate the different bioavailability measures (presented as different Ni dose metrics), for their ability to predict higher plant toxicity in naturally aged contaminated soils. For this comparison, the various toxicity thresholds (EC50 [Ni]Tiss, EC50 {Ni2+}Pore) were backcalculated to [Ni]Tot based on MLR relationships of soil chemistry. Some of these relationships were described in Methods and Materials section. For TRA, the relationship to [Ni]Tot was derived using chemistry of the test soils (n = 23):where [Ni]Tot and [Ni]Tiss and OM are all in mg/kg. See Table S2 in the online Supplementary Information (SI) for the input data used for the above MLR, and the corresponding standard errors of each coefficient. The R2 value was 0.97.
Acute copper overload induces vascular dysfunction in aortic rings due to endothelial oxidative stress and increased nitric oxide production
Published in Journal of Toxicology and Environmental Health, Part A, 2018
Karolini Zuqui Nunes, Mirian Fioresi, Vinicius Bermond Marques, Dalton Valentim Vassallo
All values were expressed as mean ± SEM. Contractile responses were expressed as % maximal response induced by 75 mM KCl. The vasodilator responses are expressed as % previous contraction. For each concentration–response curve, the maximal effect (Rmax) and agonist concentration that produced 50% of the maximal response (log EC50) were calculated using nonlinear regression analysis (GraphPad Prism, GraphPad Software, Inc., San Diego, CA, USA). Agonist sensitivities were expressed as pD2 (-log EC50). To compare the effect of drugs on aortic ring response to PHE, some results were expressed as differences of the area under the concentration–response curves (dAUC) in control and experimental situations. AUCs were calculated from individual concentration–response curve plots; differences were expressed as % control AUC (without intervention). Differences were analyzed using Student’s t-test. p < .05 was considered statistically significant.