Assessment of the use of red mud as a catalyst for photodegradation of bisphenol A in wastewater treatment

2016 ◽  
Vol 74 (6) ◽  
pp. 1283-1295 ◽  
Author(s):  
Raquel Vieira Busto ◽  
Maraisa Gonçalves ◽  
Lúcia Helena Gomes Coelho
Keyword(s):  
Wastewater Treatment ◽  
Bisphenol A ◽  
Red Mud ◽  
Vibrio Fischeri ◽  
Degradation Kinetics ◽  
Chemical Reduction ◽  
Aluminum Production ◽  
Synthetic Sample ◽  
Effluent Sample ◽  
Degradation Rates

This study aimed to investigate the use of red mud (RM) – a byproduct of aluminum production, as a photocatalyst, which was characterized physical-chemically and used in the photodegradation of the target compound bisphenol A (BPA). Chemical processing was performed in the RM (acid treatment, chemical reduction and calcination) to verify the most active catalyst. From the results obtained, a complete degradation kinetics of BPA was carried out using a synthetic matrix (BPA in deionized water) and a real matrix (BPA in wastewater) using natural RM/calcined and TiO2 for comparison. The results indicated the potential use of the RM/calcined, which was able to degrade between 88 and 100% of the pollutant in a synthetic sample. Tests on a real effluent sample resulted in degradation rates that ranged from 59 to 100% with chemical oxygen demand reductions of up to 23% using natural RM/calcined in comparison to TiO2. The blank system (irradiation of the solution without the use of a photocatalyst) and the natural RM/calcined one, resulted in reductions of the toxicity in the effluent sample (measured by EC20 using the marine bacteria Vibrio fischeri) of about 12 times, whereas the same treatment using TiO2 resulted in a toxicity reduction of only seven times. Within these results, the RM/calcined showed potential to be used in wastewater treatment in polishing processes.

Semiconductor-mediated photocatalysed degradation of two selected pesticide derivatives, terbacil and 2,4,5-tribromoimidazole, in aqueous suspension

2001 ◽  
Vol 44 (5) ◽  
pp. 331-337 ◽  
Author(s):  
M. Muneer ◽  
D. Bahnemann
Keyword(s):  
Hplc Analysis ◽  
Model Compound ◽  
Vibrio Fischeri ◽  
Degradation Kinetics ◽  
Irradiation Time ◽  
Aqueous Suspension ◽  
Toxicity Tests ◽  
Tio2 Photocatalyst ◽  
Degradation Rates ◽  
Ph Stat

The photocatalysed degradation of two selected pesticide derivatives, namely 3-tert-butyl-5-chloro-6-methyluracil (terbacil) and 2,4,5-tribromoimidazole (TBI) has been investigated in aqueous suspensions of titanium dioxide (TiO2) under a variety of conditions employing a pH-stat technique. The degradation was studied by monitoring the change in substrate concentration of the model compound employing HPLC analysis, and the decrease in total organic carbon (TOC) content, respectively, as a function of irradiation time. The degradation kinetics were studied under different conditions such as reaction pH, substrate and photocatalyst concentration, type of TiO2 photocatalyst and the presence of alternative additives such as H2O2, KBrO3 and (NH4)2S2O8 besides molecular oxygen. The degradation rates and the photonic efficiencies were found to be strongly influenced by the above parameters. Toxicity tests for the irradiated samples of the pesticide derivatives measuring the luminescence of bacteria Vibrio fischeri after 30 minutes of incubation were also performed.

Semiconductor-Mediated Photocatalysed Degradation of Various Pesticide Derivatives and Other Priority Organic Pollutants in Aqueous Suspensions

2005 ◽  
Vol 486-487 ◽  
pp. 61-64
Author(s):  
Detlef W. Bahnemann ◽  
M. Muneer ◽  
M. Qamar ◽  
M.A. Rahman ◽  
H.K. Singh
Keyword(s):  
Titanium Dioxide ◽  
Organic Carbon ◽  
Organic Pollutants ◽  
Spectroscopic Analysis ◽  
Vibrio Fischeri ◽  
Degradation Kinetics ◽  
Irradiation Time ◽  
Aqueous Suspensions ◽  
Degradation Rates ◽  
Hplc Technique

The photocatalysed degradation of various selected pesticide derivatives, namely N,NDimethyl- a-phenyl benzene acetamide (Diphenamid) [1], 1,2-diethyl phthalate (DEP) [2], 5-bromo- 3-sec.butyl-6-methyl uracil (Bromacil) [3], 3-tert-butyl-5-chloro-6-methyluracil (Terbacil), 2,4,5- tribromoimidazole (TBI) [4], Methoxychlor, Chlorothalonil and Disulfoton [5] as well as that of two selected priority organic pollutants, namely benzidine and 1,2-diphenyhydrazine (DPH) [6], has been investigated in aqueous suspensions of titanium dioxide (TiO2) under a variety of conditions. The degradation was studied by monitoring the change in substrate concentration employing UV spectroscopic analysis or HPLC technique and the decrease in total organic carbon (TOC) content, respectively, as a function of irradiation time. The degradation kinetics was studied under different conditions such as reaction pH, substrate and photocatalyst concentration, type of photocatalysts and the presence of alternative additives such as H2O2, KBrO3 and (NH4)2S2O8 besides molecular oxygen. The degradation rates and the photonic efficiencies were found to be strongly influenced by the above parameters. A toxicity test was performed for irradiated samples of few selected systems measuring the luminescence of bacteria Vibrio fischeri after 30 minutes of incubation.

Biotreatability test of bleach wastewaters from pulp and paper mills

1997 ◽  
Vol 35 (2-3) ◽  
pp. 101-108
Author(s):  
X. Wang ◽  
T. H. Mize ◽  
F. M. Saunders ◽  
S. A. Baker
Keyword(s):  
Wastewater Treatment ◽  
Pulp And Paper ◽  
Reductive Dehalogenation ◽  
Continuous Reactor ◽  
Batch Reactors ◽  
Aerobic Treatment ◽  
Pulp And Paper Mills ◽  
Paper Mills ◽  
Degradation Rates ◽  
Adsorbable Organic Halide

Research is focused on an integrated way to simultaneously optimize the bleaching operations and subsequent wastewater treatment for pulp and paper mills. Bleach wastewaters from ClO2-bleached pulping studies at Institute of Paper Science and Technology (IPST) were used as the feed for batch reactors to test and rank the treatability and kinetics. The key aspect of the system is the use of sequential anaerobic/aerobic phases to enhance reductive dehalogenation of chloro-organic materials. Two continuous reactor systems, one operated in an anaerobic-aerobic mode and a second in an aerobic-aerobic mode, received bleaching wastewater obtained from a full-scale plant. Acclimated cultures from both continuous reactors were used to quantify the AOX (Adsorbable Organic Halide) and COD removal from various bleaching wastewaters. In general, the sequential anaerobic/aerobic treatment of bleach wastewater can improve both biotreatability and degradation rates.

Chemical characteristics and in situ ruminal parameters of barley for cattle: Comparison of the malting cultivar AC Metcalfe and five feed cultivars

2008 ◽  
Vol 88 (4) ◽  
pp. 711-719 ◽  
Author(s):  
Kenton J Hart ◽  
Brian G Rossnagel ◽  
Peiqiang Yu
Keyword(s):  
Nutritive Value ◽  
Degradation Kinetics ◽  
Starch Degradation ◽  
Barley Cultivars ◽  
Degradation Rates ◽  
Key Words Barley ◽  
In Situ Degradation ◽  
The Mean ◽  
Pass Through

The objective of this study was to compare the most widely grown barley cultivar in Canada, AC Metcalfe, a malting type barley, with five feed cultivars. Barley cultivars were grown at one location during 3 consecutive years and barley samples were milled to pass through a 1-mm screen and analysed to determine nutritive value. Additional samples were passed through a roller mill with a gap set at 1.12 mm and incubated ruminally for 0, 2, 4, 8, 12, 24, and 48 h in 3 dry Holstein cows fitted with rumen cannulae. The rate and extent of rumen digestion were estimated. AC Metcalfe had a higher (P < 0.001) concentration of NDF, and lower (P < 0.05) concentrations of non structural carbohydrates, starch, ADF, total digestible nutrients, and fermentable cell wall carbohydrates compared with the mean of the feed cultivars. The malting cultivar had a higher (P < 0.001) soluble DM fraction, lower (P < 0.05) CP and starch degradation rates, and a lower (P < 0.001) ruminally degradable starch concentration compared with the mean of the five feed cultivars. The results demonstrate that there are only small differences in terms of chemical composition and in situ degradation kinetics between the malting cultivar AC Metcalfe and the five feed cultivars of barley reported here. Key words: Barley, energy, protein, ruminants

Deactivation of Red Mud by Primary Aluminum Production Wastes

2021 ◽  
Vol 1040 ◽  
pp. 109-116
Author(s):  
V.Yu. Piirainen ◽  
A.A. Barinkova ◽  
V.N. Starovoytov ◽  
V.M. Barinkov
Keyword(s):  
Carbon Dioxide ◽  
Red Mud ◽  
Negative Impact ◽  
Waste Product ◽  
Primary Aluminum ◽  
Raw Material ◽  
Aluminum Production ◽  
Environmentally Safe ◽  
Primary Aluminum Production ◽  
Knowledge Intensive

Current global environmental challenges and, above all, global warming associated with a change in the carbon balance in the atmosphere has led to the need for urgent and rapid search for ways to reduce greenhouse gas emissions into the atmosphere, which primarily include carbon dioxide as a by-product of human activity and technological progress. One of these ways is the creation of industries with a complete cycle of turnover of carbon dioxide. Aluminum is the most sought-after nonferrous metal in the world, but its production is not environmentally safe, so it constantly requires the development of knowledge-intensive technologies to improve the technological process of cleaning and disposal of production waste, primarily harmful emissions into the atmosphere. Another environmental problem related to aluminum production is the formation and accumulation in mud lagoon of huge amounts of so-called highly alkaline "red mud," which is a waste product of natural bauxite raw material processing into alumina - the feedstock for aluminum production. Commonly known resources and technological methods of neutralizing red mud and working with it as ore materials for further extraction of useful components are still not used because of their low productivity and cost-effectiveness. This article describes the negative impact of waste in the form of "red" mud and carbon dioxide of primary aluminum production on the environment. The results showed that thanks to carbonization of red mud using carbon dioxide, it is possible to achieve rapid curing and its compact formation for safer transportation and storage until further use. Strength tests of concrete samples filled with deactivated red mud were also carried out, which showed the prospects of using concrete with magnesia binder.

Modeling Bioaugmentation Potential for Enhanced Bisphenol A Removal During Wastewater Treatment

2014 ◽  
Vol 2014 (16) ◽  
pp. 6819-6833
Author(s):  
Nicolette A. Zhou ◽  
John F. Ferguson ◽  
Heidi L. Gough
Keyword(s):  
Wastewater Treatment ◽  
Bisphenol A

Stress–response relationships related to ageing and death of orthodox seeds: a study comparing viability and RNA integrity in soya bean (Glycine max) cv. Williams 82

2020 ◽  
Vol 30 (2) ◽  
pp. 161-172
Author(s):  
Christina Walters ◽  
Margaret B. Fleming ◽  
Lisa M. Hill ◽  
Emma J. Dorr ◽  
Christopher M. Richards
Keyword(s):  
Degradation Kinetics ◽  
Rna Degradation ◽  
Soya Bean ◽  
Rna Integrity ◽  
Viability Loss ◽  
Rna Integrity Number ◽  
Oxidative Stresses ◽  
Degradation Rates ◽  
Highly Correlated ◽  
Kinetics Of

AbstractCharacterizing non-lethal damage within dry seeds may allow us to detect early signs of ageing and accurately predict longevity. We compared RNA degradation and viability loss in seeds exposed to stressful conditions to quantify relationships between degradation rates and stress intensity or duration. We subjected recently harvested (‘fresh’) ‘Williams 82’ soya bean seeds to moisture, temperature and oxidative stresses, and measured time to 50% viability (P50) and rate of RNA degradation, the former using standard germination assays and the latter using RNA Integrity Number (RIN). RIN values from fresh seeds were also compared with those from accessions of the same cultivar harvested in the 1980s and 1990s and stored in the refrigerator (5°C), freezer (−18°C) or in vapour above liquid nitrogen (−176°C). Rates of viability loss (P50−1) and RNA degradation (RIN⋅d−1) were highly correlated in soya bean seeds that were exposed to a broad range of temperatures [holding relative humidity (RH) constant at about 30%]. However, the correlation weakened when fresh seeds were maintained at high RH (holding temperature constant at 35°C) or exposed to oxidizing agents. Both P50−1 and RIN⋅d−1 parameters exhibited breaks in Arrhenius behaviour near 50°C, suggesting that constrained molecular mobility regulates degradation kinetics of dry systems. We conclude that the kinetics of ageing reactions at RH near 30% can be simulated by temperatures up to 50°C and that RNA degradation can indicate ageing prior to and independent of seed death.

scholarly journals Reductive Smelting of Neutralized Red Mud for Iron Recovery and Produced Pig Iron for Heat-Resistant Castings

Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 32 ◽  
Author(s):  
Dmitry Valeev ◽  
Dmitry Zinoveev ◽  
Alex Kondratiev ◽  
Dmitry Lubyanoi ◽  
Denis Pankratov
Keyword(s):  
Red Mud ◽  
Slag Phase ◽  
Maximum Efficiency ◽  
Aluminum Production ◽  
Pig Iron ◽  
Iron Recovery ◽  
Furnace Temperature ◽  
Iron Phase ◽  
Low Sulfur Content ◽  
Low Sulfur

The chemical and mineral composition of the red mud from the Ural Aluminum Plant were studied by XRF, XRD, and Mössbauer spectroscopy. Experiments on reductive smelting of red mud were carried out in a range of temperatures (1650–1750 °C) to recover iron from the aluminum production waste with maximum efficiency. It was found that it is possible to obtain pig iron with a high content of titanium, phosphorus, and vanadium, and low sulfur content. The efficiency of iron recovery at 1750 °C was found to be around 98%. Thermodynamic calculations were carried out to assist in finding the optimal conditions for the process (e.g., carbon content, furnace temperature, slag liquidus temperature). It was also found that the pig iron phase obtained at 1650 to 1700 °C is not separated from the slag phase into ingot compared with the sample obtained at 1750 °C. Pig iron obtained at 1750 °C can be used to produce molds for the steel-casting equipment.

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