scholarly journals The Recycling of Acid Wastewater with High Concentrations of Organic Matter: Recovery of H2SO4 and Preparation of Activated Carbon

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 183
Author(s):  
Xingyun Hu ◽  
Linghao Kong ◽  
Feng Zhu ◽  
Xianjia Peng

Little work has been focused on the recycling of hazardous acid waste with high concentrations of organic matter from petroleum refining. This study developed an innovative, effective, and simple method for the recycling of acid waste that can successfully resolve this significant problem in industry. After parameter optimization, the optimal process is as follows. (1) Through heat treatment at 170 °C, liquid acid waste was transformed into solid; (2) by washing the solids, 70% by weight of sulfuric acid was recycled; and (3) the solid residue after washing was activated by alkali (NaOH or KOH) at an alkali and organic carbon ratio of 2:1, at a temperature of 650 °C for 60 min, producing superior-grade activated carbon with a specific surface area of 1378 m2/g, a pore volume of 0.5107 cm2/g, an iodine number of 1800 mg/g, and a methylene blue adsorption capacity of 240 mg/g. Thus, in this way, both waste sulfuric acid and organic impurities are turned into valuable resources, and no hazardous waste gypsum residues are generated. This method both reduces carbon emissions and recycles valuable resources, which is of important environmental and economic significance.

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1731
Author(s):  
Chih-Chung Lai ◽  
Feng-Hao Hsu ◽  
Su-Yang Hsu ◽  
Ming-Jay Deng ◽  
Kueih-Tzu Lu ◽  
...  

The specific energy of an aqueous carbon supercapacitor is generally small, resulting mainly from a narrow potential window of aqueous electrolytes. Here, we introduced agarose, an ecologically compatible polymer, as a novel binder to fabricate an activated carbon supercapacitor, enabling a wider potential window attributed to a high overpotential of the hydrogen-evolution reaction (HER) of agarose-bound activated carbons in sulfuric acid. Assembled symmetric aqueous cells can be galvanostatically cycled up to 1.8 V, attaining an enhanced energy density of 13.5 W h/kg (9.5 µW h/cm2) at 450 W/kg (315 µW/cm2). Furthermore, a great cycling behavior was obtained, with a 94.2% retention of capacitance after 10,000 cycles at 2 A/g. This work might guide the design of an alternative material for high-energy aqueous supercapacitors.


2006 ◽  
Vol 53 (11) ◽  
pp. 205-212 ◽  
Author(s):  
M. Le Noir ◽  
B. Guieysse ◽  
B. Mattiasson

This work was conducted to study the potential of molecularly imprinted polymers (MIPs) for the removal of oestradiol at trace concentrations (1 ppm–1 ppb). An MIP synthesised with 17β-oestradiol as template was compared to non-imprinted polymers (NIP) synthesised under the same conditions but without template, a commercial C18 extraction phase and granulated activated carbon. At 1 ppb oestradiol was recovered by 98±2% when using the MIP, compared to 90±1, 79±1, and 84±2% when using the NIP, a C18 phase, or granulated activated carbon, respectively. According to these levels, the MIP was capable of producing an effluent with a quality 5–10 times higher than the other materials. The same levels of oestradiol recovery were achieved with the MIP when supplying 17β-oestradiol at 0.1 ppm. Phenolic compounds added as interferences bound less to the MIP than to the NIP, confirming the selectivity of the MIP. Oestradiol biodegradation was also demonstrated at high concentrations (50 ppm), showing the pollutants can be safely destructed after being enriched by molecular extraction. This study demonstrates the potential of molecular imprinted polymers as a highly efficient specific adsorbent for the removal of trace contaminants.


2012 ◽  
Vol 46 (14) ◽  
pp. 7905-7912 ◽  
Author(s):  
Eric A. Morris ◽  
Donald W. Kirk ◽  
Charles Q. Jia ◽  
Kazuki Morita

2013 ◽  
Vol 316-317 ◽  
pp. 323-326
Author(s):  
Chao Jie Zhang ◽  
Si Bo Li ◽  
Qian Chen ◽  
Qi Zhou

Dissolved organic matter (DOM) may do harms to human beings. After disinfected by chlorine (amine), DOM can form disinfection by-products (DBPs) which can be mutagenic, teratogenic and carcinogenic. Characterization and source of trihalomethane precursors in the secondary effluent by sequencing batch reactors were investigated. CHCl3 was the primary DBPs. The results showed that the precursors of CHCl3 were mainly strongly hydrophobic DOM, while CHCl2Br and CHClBr2 were mainly formed from hydrophilic DOM. The effects of different powder media (activated carbon, zeolite) on removal of DOM were compared. The results showed that the dosing of powder media can promote the removal of DOM and the DBPs precursors.


2006 ◽  
Vol 86 (1) ◽  
pp. 57-60 ◽  
Author(s):  
T. E. Redding ◽  
K. J. Devito

Particle density is a fundamental soil physical property, yet values of soil and organic matter particle density (ρs and ρo) vary widely in the literature. We measured particle density of organic soils from five wetland types, and from exposed sediments of drying ponds, in northern Alberta, Canada. Our measured values of organic soil and pond sediment ρs varied widely (1.43–2.39 Mg m-3); however, calculated values of ρo (1.34–1.52 Mg m-3) were relatively constant. The measured and calculated ρs and ρo values were similar to those obtained in published studies using similar methods, but were higher than the values provided in many reference texts. Given the relatively small variability in ρo, the use of mean values of ρo, combined with measurements of organic matter loss-on-ignition, shows promise as a simple method for obtaining reliable estimates of ρs across a range of wetland types. Key words: Particle density, peat, organic matter, wetland soil, loss-on-ignition


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