Removal of recalcitrant organic substances in livestock wastewater using ozonation and an electrochemical process

2018 ◽  
Vol 135 ◽  
pp. 399-407
Author(s):  
Yeojoon Yoon ◽  
Moonki Park ◽  
Minhwan Kwon ◽  
Youmi Jung ◽  
Tae-Mun Hwang ◽  
...  
Author(s):  
E. V. Komarova ◽  
◽  
A. V. Slabunova ◽  
S. E. Haritonov ◽  
◽  
...  

Purpose: to analyze the advantages of cavitation disinfection of wastewater of various origins, including animal husbandry wastewater. Discussion. The problem of purification and utilization of livestock wastewater in Russia is quite acute, as well as the search for an alternative source of water for irrigating crops, one of the ways of solving these problems is the use of wastewater in irrigation. However, such a solution, in its turn, has its own difficulties associated with sanitary and hygienic requirements, large capital investments are needed to prepare wastewater for irrigation, the conventional treatment systems are large and complex. This arouses particular interest to the study of water disinfection by cavitation treatment. The analysis showed that the cavitation method has established itself as a reagent-free, economically and energetically beneficial water disinfection, which is used in many areas of activity. Conclusions: the cavitation method of purification and disinfection of various types of wastewater has clear advantages over existing methods. However, it requires further deeper and more detailed study of the disinfection process of wastewater from animal husbandry with the possibility of obtaining a purified and disinfected liquid, rich in organic substances, having a fertilizing value during irrigating crops.


2020 ◽  
Vol 17 (34) ◽  
pp. 62-66
Author(s):  
Claudemir BATALINI ◽  
Wagner Ferraresi DE GIOVANI

Various organic functions can undergo oxidation reactions, and the chemical industry increasingly seeks to develop processes based on the Green Chemistry approach in the search for more sustainable practices. Electrochemical electron transfer processes using metal complexes thus appear as an important alternative in these oxidative processes since they exploit numerous reactions in aqueous media and use catalytic amounts of the complex. The purpose of this work was to test the electrocatalytic ability of a new ruthenium (II) diarsenic aqua complex, [Ru(L)(totpy)(OH2)](ClO4)2 (L=Ph2AsCH2CH2AsPh2); (totpy=4´-(4-tolyl)-2,2´:6´,2´´-terpyridine), in electrooxidation experiments of organic substances with different functions. The experiments were conducted at a constant potential of +1.00 V (vs ECS) in a solution of 7:3 phosphate buffer: t-butanol, pH 8.1, with a ratio of 1.00 mmol.L-1 of the aqua complex [Ru(L)(totpy)(OH2)](ClO4)2 to 50.00 mmol.L-1 of each organic substrate. The oxidized organic starting materials and the respective products obtained therefrom were benzyl alcohol (benzaldehyde), benzaldehyde (benzoic acid), benzyl butyl ether (benzaldehyde and benzoic acid) and 1-phenylethanol (acetophenone). Selective reactions with good yields for the products were observed. The electrochemical process used here revealed some benefits over other classic oxidative methods, such as biological advantages and inorganic oxidants, emphasizing the speed, the possibility of using aqueous media in the reactions, selectivity in the formation of products, and the possibility of using small amounts of catalyst.


Author(s):  
Rebecca W. Keller ◽  
Carlos Bustamante ◽  
David Bear

Under ideal conditions, the Scanning Tunneling Microscope (STM) can create atomic resolution images of different kinds of samples. The STM can also be operated in a variety of non-vacuum environments. Because of its potentially high resolution and flexibility of operation, it is now being applied to image biological systems. Several groups have communicated the imaging of double and single stranded DNA.However, reproducibility is still the main problem with most STM results on biological samples. One source of irreproducibility is unreliable sample preparation techniques. Traditional deposition methods used in electron microscopy, such as glow discharge and spreading techniques, do not appear to work with STM. It seems that these techniques do not fix the biological sample strongly enough to the substrate surface. There is now evidence that there are strong forces between the STM tip and the sample and, unless the sample is strongly bound to the surface, it can be swept aside by the tip.


1884 ◽  
Vol 18 (445supp) ◽  
pp. 7103-7104
Author(s):  
Otto Schnurrer
Keyword(s):  

2004 ◽  
Vol 35 (5-6) ◽  
pp. 387-392
Author(s):  
V. A. Borodulya ◽  
L. M. Vinogradov ◽  
S. A. Zhdanok ◽  
A. V. Krauklis

2016 ◽  
pp. 3287-3297
Author(s):  
Tarek El Ashram ◽  
Ana P. Carapeto ◽  
Ana M. Botelho do Rego

Tin-bismuth alloy ribbons were produced using melt-spinning technique. The two main surfaces (in contact with the rotating wheel and exposed to the air) were characterized with Optical Microscopy and AFM, revealing that the surface exposed to the air is duller (due to a long-range heterogeneity) than the opposite surface. Also the XPS chemical composition revealed many differences between them both on the corrosion extension and on the total relative amounts of tin and bismuth. For instance, for the specific case of an alloy with a composition Bi-4 wt % Sn, the XPS atomic ratios Sn/Bi are 1.1 and 3.7 for the surface in contact with the rotating wheel and for the one exposed to air, respectively, showing, additionally, that a large segregation of tin at the surface exists (nominal ratio should be 0.073). This segregation was interpreted as the result of the electrochemical process yielding the corrosion products.


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