disinfection process
Recently Published Documents


TOTAL DOCUMENTS

190
(FIVE YEARS 72)

H-INDEX

15
(FIVE YEARS 3)

Author(s):  
Yingzi Lin ◽  
Mingliang Zhou ◽  
Gaoqi Wang ◽  
Hao Li ◽  
Yuhang Wei ◽  
...  

Author(s):  
George Antonio Belmino da Silva ◽  
Whelton Brito dos Santos ◽  
Thiago Santos de Almeida Lopes ◽  
Weruska Brasileiro Ferreira ◽  
Andréa Carla Lima Rodrigues

Abstract Disinfection process is used in the treatment of water for human supply to promote sanitary safety and provide users with drinking water that meets potability standards. Thus, it is necessary to sustain a minimal concentration of free residual chlorine (FRC) throughout the entire distribution system. The present study investigated the decay process of FRC concentration in water destined for human supply. The decay was evaluated in bench-scale testing, using sodium hypochlorite, calcium hypochlorite, sodium dichloroisocyanurate (organic chlorine) as disinfectant agents, and also an alternative disinfectant solution (ADS) produced in loco, with oxidizing and disinfectant properties, which is being used in Brazilian sanitation industry. To evaluate the decay, four models were fitted: first-order, nth-order, limited first-order and parallel first-order, hence determining the corresponding parameters which describe the decay speed of the FRC concentration in water. Achieved results demonstrated that all models were statistically significant and predictive. However, parallel first-order model produced the best fit. Regarding the evaluated disinfectants, it was noted the preeminence of ADS solution when compared to the others, since it imparted a higher FRC over time, a behavior indicated by lower values for reaction rate constant in all models and when compared to other disinfectants used in this study.


2021 ◽  
Author(s):  
Ehsan Sohrabi ◽  
Somayeh Sohrabi ◽  
Davood Iranshahi ◽  
Majid Sarmadi ◽  
Mostafa Keshavarz Moraveji

Abstract Since the operating conditions of the cooling tower units provide such a suitable environment for the growth of bacteria and algae, taking measures for the disinfection process is strongly recommended. The cooling tower unit is proceeded by RO and the disinfection strategy is sodium hypochlorite, combined with this new formulation. The sampling result revealed that bacteria counts from the effluent of the cooling tower are 2600 CFU/ml while the microbial load of the water in the pond is 220 CFU/ml. Herein, two type formulations are introduced for cooling tower output stream while the pond water comes along with a NaOCl injection. The dosage of A: Glucose Oxidase, B: ammonium persulfate, and C: Amoxicillin, and D: the order of use are chosen as the four independent variables whose effects and their binary interactions on microbial load and disinfection efficiency were investigated via Box–Behnken design (BBD) combined with response surface methodology (RSM). The ANOVA results show that the most significant variable is amoxicillin in the presence of bleach. Meanwhile, high values for R2 > 0.99 and the model F-value 45.64 in addition to diagnostic tests confirmed the reliability of the model. Several solutions have been introduced as optimum formulations. The pre-scale up and economic considerations have been included.


2021 ◽  
Author(s):  
Paloma Ohana Sousa Abreu ◽  
Julio Lenin Diaz Guzman ◽  
Camila P da Silveira Martins da Mata ◽  
Ana Carolina Morais Apolônio ◽  
Uener Ribeiro dos Santos ◽  
...  

Abstract Background: Healthcare-associated infections (HAIs) represent one of the main causes for the morbidity and mortality in the intensive care unit (ICU). In this study, we aimed to verify the presence, type, and antimicrobial susceptibility of bacteria in ICU settings, before and after disinfection procedures, and analyze the risk of contamination related to these bacteria in each area of the ICU.Methods: The study was conducted in the ICU of a medium-sized hospital in Brazil from February 2019 to February 2020. Samples were obtained from the surfaces of beds, bathrooms, pantries, sinks, pharmacies, administrative areas, and floors, before and after the disinfection process, with 1% benzalkonium chloride and biguanide mixture (BCB). The samples were processed and inoculated in different culture media for the selective isolation of strains of clinical interest. In addition, phenotypic identification and antimicrobial susceptibility tests were performed using the VITEK® 2 system. We grouped different environmental, temporal, and microbial factors and characteristics to calculate the risk of contamination before disinfection (Rbd) and after disinfection (Rad), as well as the total risk (Rtt) and real risk observed (Foldrisk) in the ICU.Results: Gram-positive cocci and rods, gram-negative rods of the Enterobacteriaceae family, and non-fermenting gram-negative rods were recovered after disinfection and were found to be widely distributed. Higher bacterial diversity and frequency of resistance were observed, mainly the resistance of gram-positive bacteria to cephalosporin (p < 0.05) and lincosamides (p < 0.0001), and gram-negative bacteria to quinolones (p < 0.0001) and aminoglycosides (p < 0.05). The pantry, pharmacy, and beds showed major risks of contamination after disinfection (Rad), ranging from intermediate to very high-risk levels. Foldrisk for the pantry and beds presented a significant increase in two and three risk levels, respectively, after the disinfection process.Conclusions: Our results demonstrate the presence of bacterial pathogens with multidrug-resistant profiles after disinfection with a higher risk of contamination, indicating that challenges still exist in the deployed disinfection protocols in the ICU settings, which are associated with the increased critical risk of HAIs after the disinfection procedure.


2021 ◽  
Vol 1 (1) ◽  
pp. e004
Author(s):  
Juan A. Vega Farje ◽  
Ana Gonzalez ◽  
Fanny L. Casado

Surgical sutures are the simplest yet most used medical devices in modern healthcare,  they are the preferred type because of its biocompatibility and ability to be resorbed. Bovine intestinal fibers are converted into catgut that serves as the starting material of absorbable surgical suture threads. The mechanical and control subsystems of industrial equipment were designed to automate disinfection of bovine intestinal fibers to increase efficiency during the wet process stage of disinfection without altering its fiber quality. A turbulent regime of the water and disinfectant mix was designed, implemented and validated, this automatic aeration system in the disinfection thank          increased the process efficiency by reducing the time used to handle a load of fibers by 50%, and the working time of the personnel involved in the process was reduced from 220 to 20 minutes. Tests on the final product showed that LAL levels comply with what is established by the American Pharmacopoeia: USP <85> Bacterial Endotoxin Test and USP <161> Medical Devices - Bacterial and Pyrogen Endotoxin Test. These results indicate that the disinfected catgut using the proposed automated system complies with all mechanical quality control tests.


2021 ◽  
Vol 25 (5) ◽  
Author(s):  
Tim Sandle

This paper assesses the transfer disinfection process, the available technologies and critical bio-decontamination aspects, focusing on the important criteria for device assessment and operation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Angila Ataei-Pirkooh ◽  
Ali Alavi ◽  
Mehran Kianirad ◽  
Kowsar Bagherzadeh ◽  
Alireza Ghasempour ◽  
...  

AbstractIn this pandemic SARS-CoV-2 crisis, any attempt to contain and eliminate the virus will also stop its spread and consequently decrease the risk of severe illness and death. While ozone treatment has been suggested as an effective disinfection process, no precise mechanism of action has been previously reported. This study aimed to further investigate the effect of ozone treatment on SARS-CoV-2. Therefore, virus collected from nasopharyngeal and oropharyngeal swab and sputum samples from symptomatic patients was exposed to ozone for different exposure times. The virus morphology and structure were monitored and analyzed through Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Atomic Absorption Spectroscopy (AAS), and ATR-FTIR. The obtained results showed that ozone treatment not only unsettles the virus morphology but also alters the virus proteins’ structure and conformation through amino acid disturbance and Zn ion release from the virus non-structural proteins. These results could provide a clearer pathway for virus elimination and therapeutics preparation.


Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2559
Author(s):  
Cuimin Feng ◽  
Tong Wei ◽  
Shan Qing ◽  
Fang Han ◽  
Xingcheng Tao

To reduce the risk of by-products from traditional disinfection technology and to ensure safe water quality, tea polyphenols (TP) were used as disinfectants after the ultrafiltration (UF) process. The disinfectant effect of TP was tested on the total number of bacteria and changes in bacterial community structure, and pathogen virulence factors were detected by Illumina’s high-throughput sequencing technology. The results showed that the recommended dosage of TP for water treatment after UF was 5 mg/L, which can effectively inhibit bacterial growth and maintain the disinfectant effect for up to 48 h later. In the disinfection process, the degradation of the tea polyphenols concentration was fitted to the equation of the second order reaction kinetics. The lower the initial concentration and the higher the reaction temperature, the faster the TP decay. The metagenomic analysis of the microorganisms indicated that disinfection with tea polyphenols reduced the diversity of microorganisms in the water and altered the structure of the bacterial community. The existence of tea polyphenols also significantly inhibited the growth of potential common Gram-negative pathogens, especially Mycobacterium. TP disinfectant can also reduce the diversity and abundance of pathogenic bacterial virulence factors and improve biological safety in drinking water.


Sign in / Sign up

Export Citation Format

Share Document