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Displaying publications 41 - 44 of 44 in total

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Ethylbenzene and toluene interactions with biochar from municipal solid waste in single and dual systems

Jayawardhana Y, Keerthanan S, Lam SS, Vithanage M

Environ Res, 2021 06;197:111102.
PMID: 33798520 DOI: 10.1016/j.envres.2021.111102

The present study investigated adsorptive removal of toluene and ethylbenzene from the aqueous media via using biochar derived from municipal solid waste (termed "MSW-BC") in a single and binary contaminant system at 25-45 °C. The adsorption was evaluated at different pH (3-10), experimental time (up to 24 h), and initial adsorbate concentrations (10-600 μg/L) in single and binary contaminant system. A fixed-bed column experiment was also conducted using MSW-BC (0.25%) and influent concentration of toluene and ethylbenzene (4 mg/L) at 2 mL/min of flow rate. The adsorption of toluene and ethylbenzene on the MSW-BC was mildly dependent on the pH, and the peak adsorption ability (44-47 μg/g) was recorded at a baseline pH of ~8 in mono and dual contaminant system. Langmuir and Hill are the models that match the isotherm results in a single contaminant environment for both toluene (R2 of 0.97 and 0.99, respectively) and ethylbenzene (R2 of 0.99 and 0.99, respectively) adsorption. In the binary system, the isotherm models matched in the order of Langmuir > Hill > Freundlich for toluene, whereas Hill > Freundlich > Langmuir for ethylbenzene. The adsorption in the batch experiment was likely to take place via cooperative and multilayer adsorption onto MSW-BC involving hydrophobic, π- π and n- π attractions, specific interaction such as hydrogen-π and cation-π interactions, and van der Waals interactions. The thermodynamic results indicate exothermic adsorption occurred by physical attractions between toluene and ethylbenzene, and MSW-BC. The breakthrough behavior of toluene and ethylbenzene was successfully described with Yoon-Nelson and Thomas models. The data demonstrate that the low-cost adsorbent derived from the municipal solid waste can be utilized to remove toluene and ethylbenzene in landfill leachate.

Matched MeSH terms: Toluene*
Toluene-induced leukodystrophy from glue sniffing

Lau YH, Mawardi AS, Zain NR, Viswanathan S

Pract Neurol, 2021 Oct;21(5):439-441.
PMID: 34039751 DOI: 10.1136/practneurol-2021-002942

A 33-year-old man with a history of chronic toluene abuse through glue sniffing, developed tremors, cerebellar signs and cognitive decline. MR scan of the brain showed global cerebral and cerebellar atrophy with symmetrical T2-weighted hypointensities in the basal ganglia, thalami and midbrain. After stopping glue sniffing, his tremors, ataxia of gait, speech and cognition partially improved. Early recognition and intervention of toluene-induced leukodystrophy could prevent ongoing morbidity and premature mortality.

Matched MeSH terms: Toluene/adverse effects
Fulltext A case study: Chemical health risk assessment in three footwear small industries in Bogor-Indonesia year 2019

Savira YM, Tejamaya M, Putri AA

Gac Sanit, 2021 12 22;35 Suppl 2:S374-S378.
PMID: 34929854 DOI: 10.1016/j.gaceta.2021.10.054

OBJECTIVE: This study aimed to analyse the health risks related to the use of chemicals among workers in small footwear factories.
METHODS: This was a descriptive case study conducted in three selected small footwear factories located in Ciomas, Bogor, Indonesia. The assessment was conducted using the chemical health risk assessment method by the Department of Safety and Health Malaysia Year 2018.
RESULTS: Results showed that the level of risk of chemicals through inhalation fell on the moderate and high-risk categories, indicating that high exposure could lead to carcinogenic effects. Dermal exposure was categorised as moderate risk, causing such health effects as skin and eye irritation.
CONCLUSION: Factory X, Y, and Z have been found to have a significant risk of hazardous chemical exposure (i.e., benzene and toluene), specifically at the glueing stations, either from inhalation or dermal contact.

Matched MeSH terms: Toluene/analysis
Fulltext Synergistic interaction of metal loaded multifactorial nanocatalysts over bifunctional transalkylation for environmental applications

Altındaş C, Sher F, Smječanin N, Lima EC, Rashid T, Hai IU, et al.

Environ Res, 2023 Jan 01;216(Pt 1):114479.
PMID: 36208784 DOI: 10.1016/j.envres.2022.114479

A feasible and cost-effective process for utilization of toluene and heavy reformate is the conversion of its streams by transalkylation reaction into highly valuable xylenes. The process is usually catalysed by zeolites and the challenges to overcome in transalkylation of heavy reformate with toluene over zeolites are their selectivity, activity, long-term stability, and coke formation. Current study aimed to investigate xylenes production by transalkylation reaction on the synthesized metal-doped zeolite catalysts and to characterize prepared catalysts by FTIR, SEM, EDS and BET analysis. Toluene/heavy reformate modelled mixture was utilized as a feed. For the first time Beta and ZSM-5 catalysts with 10% (w/w) cerium and 0.1% (w/w) palladium were synthesized by calcination and wet impregnation method. Catalytic tests were performed by continuous-flow gas/solid catalytic fixed bed reactor at atmospheric pressure, 2 h-1 and 5 h-1 and 250, 300, 350 and 400 °C. Experimental results revealed that the highest heavy reformate conversion (98.94%) and toluene conversion (9.82%) were obtained over H-ZSM-5, at 400 °C and 2 h-1 WHSV. The highest xylene selectivity (11.53) was achieved over H-ZSM-5, and the highest p-xylene percentage (62.40%), using Ce-ZSM-5 catalyst. ZSM-5 catalysts showed more resistance to coke deposition than Beta zeolites. The present study delivers novel approach and catalysts, which have immense potential for developing safer and inexpensive transalkylation process in industry.

Matched MeSH terms: Toluene