scholarly journals Modification of Cu2+ in polyphenol oxidase extract from purple eggplant for phenol degradation in coal wastewater treatment

2021 ◽  
Vol 882 (1) ◽  
pp. 012071
Author(s):  
A Murniati ◽  
B Buchari ◽  
S Gandasasmita ◽  
Z Nurachman ◽  
VA Kusumaningtiyas ◽  
...  

Abstract Cracking coal-forming organic compounds during the gasification process produces liquid waste containing phenolic compounds that require special handling based on their toxicity. As one of the components, there is liquid waste resulting from the coal gasification process. The purpose of this research was to study the activity of polyphenol oxidase (PPO) on phenol after the addition of Cu2+ to purple eggplant (Solanum melongena L.) extract and its potential to work more effectively in phenol biodegradation for coal wastewater containing phenol. Enzyme activity and phenol determination were carried out spectrophotometrically. The results showed PPO activity of 25.90-38.10 U/mL; 4.0 mM phenol and the activity of PPO-Cu2+ was 21.58-46.32 U/mL; 2-10 mM CuSO4; 2.0-4.0 mM phenol. Based on Michaelis Menten’s graph, the initial rate of PPO-Cu2+ was 0.015 mM/min and the initial rate of PPO was 0.15 mM/min using 2 mM phenol as a substrate. Lineweaver-Burk’s graph shows the KM of PPO-Cu2+ = 6.92 mM, which is lower than KM of PPO = 13.05 mM. Its means that the phenol response has a higher affinity for PPO-Cu2+ than PPO. The application of PPO-Cu2+ in purple eggplant extract works effectively as much as 46.7% for artificial coal liquid waste containing phenol.

Author(s):  
Marian Wiatowski ◽  
Roksana Muzyka ◽  
Krzysztof Kapusta ◽  
Maciej Chrubasik

AbstractIn this study, the composition of tars collected during a six-day underground coal gasification (UCG) test at the experimental mine ‘Barbara’ in Poland in 2013 was examined. During the test, tar samples were taken every day from the liquid product separator and analysed by the methods used for testing properties of typical coke oven (coal) tar. The obtained results were compared with each other and with the data for coal tar. As gasification progressed, a decreasing trend in the water content and an increasing trend in the ash content were observed. The tars tested were characterized by large changes in the residue after coking and content of parts insoluble in toluene and by smaller fluctuations in the content of parts insoluble in quinoline. All tested samples were characterized by very high distillation losses, while for samples starting from the third day of gasification, a clear decrease in losses was visible. A chromatographic analysis showed that there were no major differences in composition between the tested tars and that none of the tar had a dominant component such as naphthalene in coal tar. The content of polycyclic aromatic hydrocarbons (PAHs) in UCG tars is several times lower than that in coal tar. No light monoaromatic hydrocarbons (benzene, toluene, ethylbenzene and xylenes—BTEX) were found in the analysed tars, which results from the fact that these compounds, due to their high volatility, did not separate from the process gas in the liquid product separator.


2012 ◽  
Vol 550-553 ◽  
pp. 2296-2300 ◽  
Author(s):  
Xiao Jun Meng ◽  
Yu Xiu Zhang ◽  
Rong Jia ◽  
Xia Li ◽  
Tuan Yao Chai ◽  
...  

A aerobic bacterium strain P2 isolated from coking wastewater, was able to utilize phenol, o-cresol and pyridine as its sole carbon and energy source. The morphological properties and the phylogenetic analysis based on 16S rDNA sequences showed strain P2 belonged to the genus Diaphorobacter sp.. The optimum biodegradation of phenol was 37°C, pH 7.0-9.0 and 0.25% NaCl , respectively. The growth arrearage period was prolonged with the phenol concentration. The growth of Diaphorobacter P2 and phenol-degradation were inhibited completely by 50 μmol/L metal ions, such as Cu2 +, Ni2+, Cd2+ or Cr6+. Orthogonal experiment indicated the order of metal toxicity to biodegradation of P2 was Zn2+>Mn2+>Pb2+ under various heavy-metal compounds. The phenol biodegradation in coking wastewater supplemented with 2/3 beef extract peptone medium was degraded fully in 3 days, indicating that nutrient solution was beneficial for P2 growth and phenol degradation in wastewater. Those results suggest that the Diaphorobacter P2 has potential for treatment of coking wastewater.


2021 ◽  
Author(s):  
Congbin Jiang ◽  
Dan Wang ◽  
Cuiping Gong ◽  
Gang Zhang ◽  
Wen Gu ◽  
...  

2020 ◽  
Author(s):  
Lijun Wang ◽  
Xiaocheng Du ◽  
Jiajun Sun ◽  
Shuping Duan ◽  
Xin Xie

Author(s):  
B. Cornils ◽  
J. Hibbel ◽  
P. Ruprecht ◽  
R. Dürrfeld ◽  
J. Langhoff

The Ruhrchemie/Ruhrkohle variant of the Texaco Coal Gasification Process (TCGP) has been on stream since 1978. As the first demonstration plant of the “second generation” it has confirmed the advantages of the simultaneous gasification of coal: at higher temperatures; under elevated pressures; using finely divided coal; feeding the coal as a slurry in water. The operating time so far totals 9000 hrs. More than 50,000 tons of coal have been converted to syn gas with a typical composition of 55 percent CO, 33 percent H2, 11 percent CO2 and 0.01 percent of methane. The advantages of the process — low environmental impact, additional high pressure steam production, gas generation at high pressure levels, steady state operation, relatively low investment costs, rapid and reliable turn-down and load-following characteristics — make such entrained-bed coal gasification processes highly suitable for power generation, especially as the first step of combined cycle power plants.


Author(s):  
Armin Silaen ◽  
Ting Wang

Numerical simulations of the coal gasification process inside a generic 2-stage entrained-flow gasifier fed with Indonesian coal at approximately 2000 metric ton/day are carried out. The 3D Navier–Stokes equations and eight species transport equations are solved with three heterogeneous global reactions, three homogeneous reactions, and two-step thermal cracking equation of volatiles. The chemical percolation devolatilization (CPD) model is used for the devolatilization process. This study is conducted to investigate the effects of different operation parameters on the gasification process including coal mixture (dry versus slurry), oxidant (oxygen-blown versus air-blown), and different coal distribution between two stages. In the two-stage coal-slurry feed operation, the dominant reactions are intense char combustion in the first stage and enhanced gasification reactions in the second stage. The gas temperature in the first stage for the dry-fed case is about 800 K higher than the slurry-fed case. This calls for attention of additional refractory maintenance in the dry-fed case. One-stage operation yields higher H2, CO and CH4 combined than if a two-stage operation is used, but with a lower syngas heating value. The higher heating value (HHV) of syngas for the one-stage operation is 7.68 MJ/kg, compared with 8.24 MJ/kg for two-stage operation with 75%–25% fuel distribution and 9.03 MJ/kg for two-stage operation with 50%–50% fuel distribution. Carbon conversion efficiency of the air-blown case is 77.3%, which is much lower than that of the oxygen-blown case (99.4%). The syngas heating value for the air-blown case is 4.40 MJ/kg, which is almost half of the heating value of the oxygen-blown case (8.24 MJ/kg).


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6533
Author(s):  
Magdalena Pankiewicz-Sperka ◽  
Krzysztof Kapusta ◽  
Wioleta Basa ◽  
Katarzyna Stolecka

One of the most important issues during UCG process is wastewater production and treatment. Condensed gasification wastewater is contaminated by many hazardous compounds. The composition of the generated UCG-derived wastewater may vary depending on the type of gasified coal and conditions of the gasification process. The main purpose of this study was a qualitative and quantitative characterization of the UCG wastewater produced during four different UCG experiments. Experiments were conducted using semi-anthracite and bituminous coal samples at two distinct pressures, i.e., 20 and 40 bar. The conducted studies revealed significant relationships between the physicochemical composition of the wastewater and the coal properties as well as the gasification pressure. The strongest impact is noticeable in the case of organic pollutants, especially phenols, BTEX and PAH’s. The most abundant group of pollutants were phenols. Conducted studies showed significantly higher concentration levels for bituminous coal: 29.25–49.5 mg/L whereas for semi-anthracite effluents these concentrations were in much lower range 2.1–29.7 mg/L. The opposite situation occurs for BTEX, higher concentrations were in wastewater from semi-anthracite gasification: 5483.1–1496.7 µg/L, while in samples from bituminous coal gasification average BTEX concentrations were: 2514.3–1354.4 µg/L. A similar relationship occurs for the PAH’s concentrations. The higher values were in case of wastewater from semi-anthracite coal experiments and were in range 362–1658 µg/L while from bituminous coal gasification PAH’s values are in lower ranges 407–1090 µg/L. The studies conducted have shown that concentrations of phenols, BTEX and PAH’s decrease with increasing pressure. Pearson’s correlation analysis was performed to enhance the interpretation of the obtained experimental data and showed a very strong relationship between three parameters: phenols, volatile phenols and CODcr.


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