Chemicals used for treatment of water intended for human consumption. Sodium hypochlorite

2000 ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 38-44
Author(s):  
J.G. Akinbomi ◽  
◽  
E.C. Ikhide

The need to find alternative water disinfectants without negative consequential health effects is imperative in view of the link that had been established between human consumption of chlorinated water and diseases such as cancer. Therefore, this study was set out to evaluate and compare the water disinfection potential of aloe vera and sodium hypochlorite (NaOCl) in order to determine the suitability of using aloe vera as sodium hypochlorite substitute. The coliform count of the faecal thermo-tolerant coliform (non-Ecoli) isolated from well water sample was 49 cfu/100ml. Disinfectant efficacies of the NaOCl and Aloe Vera, stored under various conditions, were evaluated and compared using disc diffusion method to determine disinfection susceptibility of the isolated coliform. The two disinfectants showed increase in level of zone of inhibition of the isolated coliforms with increase in disinfectants storage concentration and sun exposure period. As a disinfectant, aloe vera seemed to be more stable when compared with NaOCl at the storage temperatures of 0, 25 and 35oC. The p-values for using aloe vera and NaOCl as disinfectants under various conditions of concentration, temperature and sun exposure period ranged between 0.247 and 1.000 indicating non-significant difference when aloe vera was used as sodium hypochlorite substitute.


2002 ◽  
Vol 2 (3) ◽  
pp. 199-204 ◽  
Author(s):  
S. Monarca ◽  
D. Feretti ◽  
I. Zerbini ◽  
C. Zani ◽  
A. Alberti ◽  
...  

The aim of this research was to study at a pilot plant the influence of peracetic acid (PAA) on the formation of mutagenic compounds in river waters used for human consumption. The results obtained using PAA were compared to those for the most commonly used disinfectant, sodium hypochlorite (NaClO). Ames test and three genotoxicity plant tests, Allium tests and Tradescantia/micronuclei (TRAD/MCN) test, were used to evaluate the mutagenic activity of disinfected water samples. Chemical analysis, using gas chromatography/mass spectrometry (GC/MS), was also performed to identify disinfection by-products (DBPs). A slight bacterial mutagenicity was found in raw river water and similar activity was detected in disinfected water samples. Plant tests gave genotoxicity only for raw river water. DBPs identified in PAA-treated water included carboxylic acids, a few non-halogenated alcohols and carbonyl-containing compounds, whereas some potentially mutagenic halogenated by-products were found in NaClO-treated samples. Although PAA appears to be promising for water potabilization, these results must be confirmed with different source waters and with higher concentrations of PAA.


Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2294
Author(s):  
Giovanni Luongo ◽  
Lucio Previtera ◽  
Afef Ladhari ◽  
Giovanni Di Fabio ◽  
Armando Zarrelli

Numerous substances from different chemical sectors, from the pharmaceutical industry to the many consumer products available for everyday usage, can find their way into water intended for human consumption and wastewater, and can have adverse effects on the environment and human health. Thus, the disinfection process is an essential stage in water and wastewater treatment plants to destroy pathogenic microorganisms but it can form degradation byproducts. Sodium hypochlorite is the most common disinfectant, but the most important drawback associated with this kind of compound is the generation of toxic disinfection byproducts. Many studies have been carried out to identify alternative disinfectants, and in the last few years, peracetic acid has been highlighted as a feasible solution, particularly in wastewater treatment. This study compares the transformations of five emerging pollutants (caffeine, tramadol, irbesartan, diclofenac, trazodone) treated with peracetic acid, to evaluate their degradation and the possible formation of byproducts with those obtained with sodium hypochlorite. Although peracetic acid has many advantages, including a wide field of use against microorganisms and a low toxicity towards animal and plant organisms, it is not as effective in the degradation of the considered pollutants. These ones are recovered substantially and are unchanged quantitatively, producing a very low number of byproducts.


2020 ◽  
Vol 9 (6) ◽  
pp. e59963467
Author(s):  
Stéfane do Prado Vilarin ◽  
Taynara Martins Rocha Teixeira ◽  
Clara Mariana Gonçalves Lima ◽  
Jorge Pamplona Pagnossa ◽  
Roseane Mendonça de Figueiredo ◽  
...  

The aim of this study was to evaluate the effect of sanitization on minimally processed cabbage (Brassica oleracea L.). This is a quantitative, descriptive and laboratorial study where the samples were submitted to three different processes: washing only in running water; washing in running water followed by the use of sodium hypochlorite-based sanitizer and, finally, washing in running water followed by sanitization using chlorinated compounds based on sodium dichloroisocyanurate. Subsequently, microbiological analyses of total coliforms Escherichia coli and Salmonella ssp. were performed. The results showed that the sodium hypochlorite-based solution did not present a reduction in microbial population, while those based on sodium dichloroisocyanurate allowed the reduction to safe levels for human consumption. A greater control in sodium hypochlorite-based products is suggested, since possibly this result was due to the low concentration of free active chlorine.


Author(s):  
Russell L. Steere ◽  
Eric F. Erbe

Thin sheets of acrylamide and agar gels of different concentrations were prepared and washed in distilled water, cut into pieces of appropriate size to fit into complementary freeze-etch specimen holders (1) and rapidly frozen. Freeze-etching was accomplished in a modified Denton DFE-2 freeze-etch unit on a DV-503 vacuum evaporator.* All samples were etched for 10 min. at -98°C then re-cooled to -150°C for deposition of Pt-C shadow- and C replica-films. Acrylamide gels were dissolved in Chlorox (5.251 sodium hypochlorite) containing 101 sodium hydroxide, whereas agar gels dissolved rapidly in the commonly used chromic acid cleaning solutions. Replicas were picked up on grids with thin Foimvar support films and stereo electron micrographs were obtained with a JEM-100 B electron microscope equipped with a 60° goniometer stage.Characteristic differences between gels of different concentrations (Figs. 1 and 2) were sufficiently pronounced to convince us that the structures observed are real and not the result of freezing artifacts.


Author(s):  
Burton B. Silver

Tissue from a non-functional kidney affected with chronic membranous glomerulosclerosis was removed at time of trnasplantation. Recipient kidney tissue and donor kidney tissue were simultaneously fixed for electron microscopy. Primary fixation was in phosphate buffered gluteraldehyde followed by infiltration in 20 and then 40% glycerol. The tissues were frozen in liquid Freon and finally in liquid nitrogen. Fracturing and replication of the etched surface was carried out in a Denton freeze-etch device. The etched surface was coated with platinum followed by carbon. These replicas were cleaned in a 50% solution of sodium hypochlorite and mounted on 400 mesh copper grids. They were examined in an Siemens Elmiskop IA. The pictures suggested that the diseased kidney had heavy deposits of an unknown substance which might account for its inoperative state at the time of surgery. Such deposits were not as apparent in light microscopy or in the standard fixation methods used for EM. This might have been due to some extraction process which removed such granular material in the dehydration steps.


Author(s):  
M. G. Williams ◽  
C. Corn ◽  
R. F. Dodson ◽  
G. A. Hurst

During this century, interest in the particulate content of the organs and body fluids of those individuals affected by pneumoconiosis, cancer, or other diseases of unknown etiology developed and concern was further prompted with the increasing realization that various foreign particles were associated with or caused disease. Concurrently particularly in the past two decades, a number of methods were devised for isolating particulates from tissue. These methods were recently reviewed by Vallyathan et al. who concluded sodium hypochlorite digestion was both simple and superior to other digestion procedures.


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