Towards the complete dechlorination of chloroacetic acids in water by sonoelectrochemical methods: Effect of the cathode material on the degradation of trichloroacetic acid and its degradation by-products

2015 ◽  
Vol 166-167 ◽  
pp. 66-74 ◽  
Author(s):  
María Deseada Esclapez ◽  
Ignacio Tudela ◽  
María Isabel Díez-García ◽  
Verónica Sáez ◽  
Pedro Bonete
Keyword(s):  
Cathode Material ◽  
Trichloroacetic Acid ◽  
Chloroacetic Acids ◽  
By Products ◽  
Complete Dechlorination

Towards the complete dechlorination of chloroacetic acids in water by sonoelectrochemical methods: Effect of the anodic material on the degradation of trichloroacetic acid and its by-products

2012 ◽  
Vol 197 ◽  
pp. 231-241 ◽  
Author(s):  
María Deseada Esclapez ◽  
Ignacio Tudela ◽  
María Isabel Díez-García ◽  
Verónica Sáez ◽  
Astrid Rehorek ◽  
...  
Keyword(s):  
Trichloroacetic Acid ◽  
Chloroacetic Acids ◽  
By Products ◽  
Complete Dechlorination

Sintesis dan Karakterisasi Na-CMC dari A-Selulosa Serabut Kelapa Sawit

2021 ◽  
Vol 1 (9) ◽  
pp. 375-381
Author(s):  
Indriani Indriani ◽  
Abu Hasan ◽  
Anerasari Meydinariasty
Keyword(s):  
Palm Oil ◽  
Trichloroacetic Acid ◽  
Reaction Medium ◽  
Synthesis Process ◽  
Optimal Composition ◽  
Palm Fiber ◽  
Oil Processing ◽  
Reaction Media ◽  
By Products

Na-CMC adalah eter polimer selulosa linier yang digunakan sebagai bahan pengental, pengemulsi dan penstabil. Salah satu bahan dasar pembuatan Na-CMC yaitu serabut kelapa sawit. Serabut kelapa sawit merupakan salah satu hasil samping terbesar yang dihasilkan dalam proses pengolahan minyak kelapa sawit dan dapat dapat dijadikan sebagai sumber selulosa karena mengandung selulosa hingga 59,60%. Tujuan dari penelitian ini untuk mendaptakan komposisi optimal campuran media reaksi isopropanol-etanol dan konsentrasi asam trikloroasetat serta konsentrasi NaOH dengan memvariasikan komposisi media reaksi isopropanol-etanol menjadi 20:80; 40:60; 50:50; 60:40 dan 80:20, sedangkan untuk konsentrasi asam trikloroasetat yaitu 15%, 20% san 25% dan untuk konsentrasi NaOH adlah 15% dan 20%. Didapat bahwa  komposisi optimal media reaksi pada proses sintesis Na-CMC terdapat pada campuran isopropanol-etanol 80:20 dengan konsentrasi asam trikloroasetat 25% dan konsentrasi NaOH 20% menghasilkan nilai DS yang tertinggi yaitu sebesar 0,8124 dengan kemurnian dan pH berturut-turut sebesar 99,68% dan 7,9.   Na-CMC is a linear cellulose polymer ether used as a thickener, emulsifier and stabilizer. One of the basic ingredients for making Na-CMC is palm fiber. Palm fiber is one of the largest by-products produced in the palm oil processing process and can be used as a source of cellulose because it contains up to 59.60% cellulose. The purpose of this study was to obtain the optimal composition of the isopropanol-ethanol reaction media mixture and the concentration of trichloroacetic acid and NaOH concentration by varying the composition of the isopropanol-ethanol reaction medium to 20:80; 40:60; 50:50; 60:40 and 80:20, while the concentrations of trichloroacetic acid were 15%, 20% and 25% and the concentrations of NaOH were 15% and 20%, respectively. It was found that the optimal composition of the reaction medium in the Na-CMC synthesis process was found in a mixture of isopropanol-ethanol 80:20 with a concentration of 25% trichloroacetic acid and 20% NaOH concentration resulting in the highest DS value of 0.8124 with purity and pH respectively. 99.68% and 7.9.

scholarly journals Electro-Absorbers: A Comparison on Their Performance with Jet-Absorbers and Absorption Columns

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 653
Author(s):  
Monserrat Castañeda-Juárez ◽  
Martín Muñoz-Morales ◽  
Fernanda Lourdes Souza ◽  
Cristina Sáez ◽  
Pablo Cañizares ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Trichloroacetic Acid ◽  
Packed Column ◽  
Scale Up ◽  
Applied Current ◽  
Absorption Column ◽  
Applied Current Density ◽  
Current Densities ◽  
Surface Jet ◽  
By Products

This work focuses on the removal of perchloroethylene (PCE) from gaseous streams using absorbers connected with electrolyzers. Two types of absorption devices (jet absorber and absorption column) were compared. In addition, it has been evaluated the different by-products generated when a simultaneous electrolysis with diamond anodes is carried out. PCE was not mineralized, but it was transformed into phosgene that mainly derivates into carbon tetrachloride. Trichloroacetic acid was also formed, but in much lower amounts. Results showed a more efficient absorption of PCE in the packed column, which it is associated to the higher gas–liquid contact surface. Jet absorber seems to favor the production of carbon tetrachloride in gaseous phase, whereas the packed column promotes a higher concentration of trichloroacetic acid in liquid. It was also evaluated the scale up of the electrolytic stage of these electro-absorption devices by using a stack with five perforated electrode packages instead of a single cell. Clarification of the effect of the applied current density on the speciation attained after the electrolysis of the absorbent has been attempted. Experiments reveal similar results in terms of PCE removal and a reduced generation of gaseous intermediates at lower current densities.

Use of urinary trichloroacetic acid as an exposure biomarker of disinfection by-products in cancer studies

2014 ◽  
Vol 135 ◽  
pp. 276-284 ◽  
Author(s):  
Lucas A. Salas ◽  
Esther Gracia-Lavedan ◽  
Fernando Goñi ◽  
Victor Moreno ◽  
Cristina M. Villanueva
Keyword(s):  
Trichloroacetic Acid ◽  
Exposure Biomarker ◽  
By Products ◽  
Cancer Studies

scholarly journals Biodegradation of six haloacetic acids in drinking water

2007 ◽  
Vol 6 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Walt Bayless ◽  
Robert C. Andrews
Keyword(s):  
Drinking Water ◽  
Trichloroacetic Acid ◽  
Distribution Systems ◽  
Water Distribution ◽  
Haloacetic Acids ◽  
Health Concern ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution ◽  
Monobromoacetic Acid ◽  
By Products

Haloacetic acids (HAAs) are produced by the reaction of chlorine with natural organic matter and are regulated disinfection by-products of health concern. Biofilms in drinking water distribution systems and in filter beds have been associated with the removal of some HAAs, however the removal of all six routinely monitored species (HAA6) has not been previously reported. In this study, bench-scale glass bead columns were used to investigate the ability of a drinking water biofilm to degrade HAA6. Monochloroacetic acid (MCAA) and monobromoacetic acid (MBAA) were the most readily degraded of the halogenated acetic acids. Trichloroacetic acid (TCAA) was not removed biologically when examined at a 90% confidence level. In general, di-halogenated species were removed to a lesser extent than the mono-halogenated compounds. The order of biodegradability by the biofilm was found to be monobromo > monochloro > bromochloro > dichloro > dibromo > trichloroacetic acid.

scholarly journals Mechanism of Capacity Fading in the LiNi0.8Co0.1Mn0.1O2 Cathode Material for Lithium-Ion Batteries

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1638 ◽  
Author(s):  
Yong-keon Ahn ◽  
Yong Nam Jo ◽  
Woosuk Cho ◽  
Ji-Sang Yu ◽  
Ki Jae Kim
Keyword(s):  
Cathode Material ◽  
Lithium Ion Batteries ◽  
Particle Surface ◽  
Lithium Ion ◽  
High Energy ◽  
Capacity Fading ◽  
Factors Affecting ◽  
Primary Particles ◽  
Axis Length ◽  
By Products

Understanding the capacity fading mechanism of the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode materials is crucial for achieving long-lasting lithium-ion batteries with high energy densities. In this study, we investigated the factors affecting the capacity fading of NCM811 during repeated cycling at high temperatures. We found that the change in the c-axis length during charging and discharging is the main cause of the formation and propagation of microcracks in the primary particles of NCM811. In addition, the electrolyte is decomposed on the microcrack surfaces and, consequently, by-products are formed on the particle surface, increasing the impedance and resulting in poor electronic and ionic connectivity between the primary particles of NCM811. In addition, the transition metals in the NCM811 cathode material are dissolved in the electrolyte from the newly formed microcrack surface between primary particles. Therefore, the electrolyte decomposition and transition metal dissolution on the newly formed surface are the major deteriorative effects behind the capacity fading in NCM811.

Efficient photolytic degradation of disinfection by-products by using a high photon flux UV system: monochloroacetic acid, dichloroacetic acid and trichloroacetic acid

2018 ◽  
Vol 18 (6) ◽  
pp. 2063-2070 ◽  
Author(s):  
Ting Li ◽  
Qian Zhang ◽  
Chaolin Li ◽  
Weidang Ai ◽  
Liangchang Zhang
Keyword(s):  
Water Solubility ◽  
Organic Pollutant ◽  
Dichloroacetic Acid ◽  
Photon Flux ◽  
Minor Effect ◽  
Mixed Solution ◽  
Chloroacetic Acids ◽  
High Photon Flux ◽  
Photolytic Degradation ◽  
By Products

Abstract Photon UV irradiation is promising for organic pollutant decomposition, such as disinfection by-products (DBPs). However, due to the photostability and high water solubility, chloroacetic acids (CAAs) decomposition using routine UV photolysis is very slow. The present study employed a high photon flux UV (3.13 × 104 μmol m−2 s−1) system to investigate its feasibility and suitability for enhancing CAAs (MCAA, DCAA and TCAA) decomposition. The results showed that increasing UV photon flux accelerated the photolysis remarkably. Under the condition of high UV photon flux 3.13 × 104 μmol m−2 s−1, almost complete degradation of 20 mg L−1 MCAA, 20 mg L−1 DCAA, and 20 mg L−1 TCAA in a mixed solution can be achieved within 50, 30 and 25 min, respectively. To the best of our knowledge, efficient photolytic degradation of CAAs in such short time has not been reported. The pseudo-first-order rate constant (kobs) steadily increases with the increasing of UV intensity, indicating that the utilization of light energy is efficient. In addition, the variation of pH from 3.2 to 9.0 showed minor effect on CAAs decomposition in this present studied system. The outcome of this study would be helpful for future employment of high photon flux UV systems for those photolytic resistant pollutants' decomposition.

scholarly journals Validation of urinary trichloroacetic acid as a biomarker of exposure to drinking water disinfection by-products

2009 ◽  
Vol 7 (3) ◽  
pp. 359-371 ◽  
Author(s):  
Weiping Zhang ◽  
Stephan Gabos ◽  
Donald Schopflocher ◽  
Xing-Fang Li ◽  
Wendy P. Gati ◽  
...  
Keyword(s):  
Drinking Water ◽  
Trichloroacetic Acid ◽  
Tap Water ◽  
Water Disinfection ◽  
Public Health Issue ◽  
Experimental Exposure ◽  
Biomarker Of Exposure ◽  
Drinking Water Disinfection ◽  
Study Participants ◽  
By Products

Disinfection by-products (DBPs) in drinking water represent a public health issue and a challenge for epidemiology to provide evidence towards the causation of various hypothesized health effects. Validation of a biomarker of exposure to DBPs is a strategy to achieve progress which has been advocated. The objective of this study was to validate urinary trichloroacetic acid (TCAA) excretion as a biomarker of exposure to DBPs in an experimental exposure cohort. A total of 52 healthy women participated in the study. Participants consumed supplied tap water for 15 d and provided urine and blood samples for TCAA measurements. The findings revealed that (1) background levels of TCAA in urine and blood were readily detectable, (2) TCAA levels in blood and urine increased with increased amounts of TCAA ingested, (3) the correlations between measurements of TCAA ingestion and urinary excretion were modest (r=0.66, p<0.001) based on one days' sampling and high (r=0.77–0.83, p<0.001) based on two to four days' sampling, (4) the correlations between measurements of TCAA ingestion and blood TCAA concentration were high (r=0.80, p<0.001) and (5) multiple days' urinary TCAA measures improved the prediction of TCAA ingestion through urinary TCAA excretion. TCAA can be a valid biomarker of exposure for DBPs in drinking water.

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