acid waste
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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.


2021 ◽  
Vol 8 ◽  
Author(s):  
Todd P. Silverstein

The proton is the smallest atomic particle, and in aqueous solution it is the smallest hydrated ion, having only two waters in its first hydration shell. In this article we survey key aspects of the proton in chemistry and biochemistry, starting with the definitions of pH and pKa and their application inside biological cells. This includes an exploration of pH in nanoscale spaces, distinguishing between bulk and interfacial phases. We survey the Eigen and Zundel models of the structure of the hydrated proton, and how these can be used to explain: a) the behavior of protons at the water-hydrophobic interface, and b) the extraordinarily high mobility of protons in bulk water via Grotthuss hopping, and inside proteins via proton wires. Lastly, we survey key aspects of the effect of proton concentration and proton transfer on biochemical reactions including ligand binding and enzyme catalysis, as well as pH effects on biochemical thermodynamics, including the Chemiosmotic Theory. We find, for example, that the spontaneity of ATP hydrolysis at pH ≥ 7 is not due to any inherent property of ATP (or ADP or phosphate), but rather to the low concentration of H+. Additionally, we show that acidification due to fermentation does not derive from the organic acid waste products, but rather from the proton produced by ATP hydrolysis.


2021 ◽  
Author(s):  
Emanuel Nkotya ◽  
Mojtaba Rostamiparsa ◽  
Csaba Szabó ◽  
Zsuzsanna Szabó-Krausz ◽  
Péter Völgyesi

<p>Recently, boric acid enriched in B-10 has received attention over natural boric acid in nuclear industry, because the elevated content of B-10 is a prospective neutron absorber. Advantages connected to the use of B-10 enriched boric acid are the increased controllability of reactor core which results in use of reduced amount of boric acid and, subsequently, the reduction in the amount of the radioactive boric acid waste produced during reactor operation. In the other hand, consequent radioactive boric acid waste requires an adequate stabilization technology as it contains fission products of health concerns, importantly C<sub>s</sub>-137. Cementation is one of the proven, commercially viable, durable, widely used, simple and flexible technology for immobilization of low-level radioactive wastes (Hyatt and Ojovan, 2019). General integrity and durability of the cementitious waste form containing boric acid is B-leachability dependent (Rostamiparsa et al, 2020). The B-10 enriched boric acid leaching is expected to control also the C<sub>s</sub>-leaching. However, no study is found in which this is proven and the different geochemical behavior and phase distribution of the B and C<sub>s</sub> might cause deviations. This calls for the investigation of the connection between B- and C<sub>s</sub>-leaching behaviors in cementitious materials, in this case, especially focusing on B-10 enriched boric acid waste form. In this ongoing experimental work the B- and C<sub>s</sub>-leaching behavior of cementitious materials are studied, which are made of Portland cement, boric acid enriched in B-10 isotope and C<sub>s</sub>Cl. Boron- and Cs-leachability from the cementitious matrix are investigated in parallel by a standardized reference leaching test (ASTM, 2017). The tests are carried out by immersing the 28 days cured cement paste samples in deionized water in a glass bottle. Leachant renewal and solution sampling are done on a daily basis for the whole leaching test period of 11 days. Analysis of leached fractions are quantitatively measured by ICP-OES. Characterization of solid samples are conducted by XRD, SEM-EDX and Raman micro-spectroscopy methods. This is the first study to shed light on the connection between B-leaching and C<sub>s</sub>-leaching in cementitious materials containing B-10 enriched boric acid.</p> <p>Acknowledgements</p> <p>Our special thanks goes to Környezettudományi Centrum, Eötvös Loránd University and the Prémium_2017-13 research grant.</p> <p>References</p> <p>ASTM (2017). Standard Test Method for Accelerated Leach Test for Diffusive Releases From        Solidified Waste and a Computer Program to Model Diffusive, Fractional Leaching from Cylindrical Waste Forms. ASTM Standard C1308-08(2017), West Conshohocken, PA.</p> <p>Hyatt, N.C & Ojovan, M.I. (2019). Special Issue: Materials for Nuclear Waste Immobilization. Materials, 12(21), 3611.</p> <p>Rostamiparsa, M., Szabó-Krausz, Z., Fábián, M., Falus, G., Szabó, C., & Völgyesi, P. (2020). Experimental assessment of interaction between boric acid enriched in boron-10 and cementitious matrix. In EGU General Assembly Conference Abstracts (p. 19441).</p>


Ionics ◽  
2021 ◽  
Author(s):  
Zhicong Ni ◽  
Xiaoyuan Zeng ◽  
Xue Li ◽  
Guanghui Xia ◽  
Shanxiong Luo ◽  
...  

2021 ◽  
Vol 677 (5) ◽  
pp. 052049
Author(s):  
O A Medennikov ◽  
N P Shabelskaya ◽  
Yu A Gaidukova ◽  
M N Astakhova ◽  
G M Chernysheva

2021 ◽  
Vol 264 ◽  
pp. 04079
Author(s):  
Sanzharbek Shamuratov ◽  
Umid Baltaev ◽  
Umarbek Alimov ◽  
Namazov Shafoat ◽  
Sherzod Kurambaev ◽  
...  

In the study, the process neutralization acid waster water from soapstock processing by high calcareous phosphorite of Central Kyzylkum at temperature 60 ºC by drainless technology was investigated. As a result, digested forms of P2O5 by citric acid and Trilon B in final products were ranged 30.28-50.43 and 25.58-39.93%, respectively. Those types of products can be used under autumn chill.


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