Comparison between Methods of Biological Crust Removal on Granite

2013 ◽  
Vol 548 ◽  
pp. 317-325 ◽  
Author(s):  
Santiago Pozo ◽  
Cristina Montojo ◽  
Teresa Rivas ◽  
Ana Jesús López-Díaz ◽  
Maria Paula Fiorucci ◽  
...  
Keyword(s):  
Benzalkonium Chloride ◽  
Aqueous Media ◽  
Infrared Spectrometry ◽  
Nw Spain ◽  
Cleaning Method ◽  
Additional Information ◽  
Biological Crust ◽  
Cleaning Procedures ◽  
Ftir Technique ◽  
Cleaning Methods

This paper presents the evaluation of the efficacy of the removal of biological crust from ornamental granites. The removal was made applying different procedures and the efficiency was evaluated by means of optic and scanning electron microscopy (SEM), Fourier Transformed Infrared spectrometry (FTIR) and colour measures (CIE-L*a*b* colour spaces). Among the cleaning procedures, an abrasive cleaning method, several chemicals-based methods applied by brush in aqueous media (using acids, bleach, benzalkonium chloride, ethanol and others) and laser (Nd:YVO4 at 355 nm) were used. This last method was previously found very efficient in removing graffiti and biological crusts in other granites. The present study was conducted on a granite of great commercial value from Galicia (NW Spain) and traditionally used on construction of historical buildings in this region and abroad. Slabs of this granite with an intense biological crust were used. Before the cleaning procedures, the biological crust was characterized by the same techniques to establish the comparison between Pre and Post cleaning. The efficacy in the crust removal was evaluated with optic and electronic microscopy; the best cleaning methods were the acid-based methods and laser. In both cases, no biological remains were found on the cleaning surfaces. Hydrogommage (the abrasive cleaning method) obtained intermediate results, and benzalkonium chloride cleaning showed the worst effectiveness. FTIR technique helped to identify the presence of organic signals of biological crust; and also, it provided useful information on the contaminant remains on the stone after cleaning and on mineral damages. Colour differences after cleaning gave additional information about the efficiency of the cleaning.

scholarly journals Comparison of cleaning methods on debris, surface roughness and static friction of retrieved stainless steel archwires

2018 ◽  
Vol 32 (3) ◽  
pp. 131
Author(s):  
Fabiano Dalla Lana Mattiello ◽  
Paulo Ricardo Baccarin Matje ◽  
Kim Beom Kim ◽  
Eduardo Gonçalves Mota ◽  
Eustáquio Afonso Araújo ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Statistical Difference ◽  
Testing Machine ◽  
Static Friction ◽  
Steel Wool ◽  
Sem Images ◽  
Cleaning Method ◽  
Cleaning Methods ◽  
Reduced Surface

OBJECTIVE: To evaluate the amount of debris, surface roughness and static friction in retrieved stainless steel (SS) archwires after four weeks of intraoral exposure and afterwards compare the effects of different cleaning methods.METHODS: The sample gathered seventeen as-received and eighty-five retrieved SS archwire segments, which were allocated in cleaning method groups (N=17): retrieved (RT); sodiumbicarbonate jet (SB-jet); ultrasonic cleaner (U-sonic); alcohol soaked gauze (A-gauze); and steel wool sponge (S-wool). Debris (SEM images), surface roughness (rugosimeter) and static friction(universal testing machine) were compared between as-received and retrieved SS wires and between cleaning method groups.RESULTS: Debris and surface roughness were statistically higher in RT wires than in as-received (p<0.001), whereas static friction showed no statistical difference (p>0.05). Debris were significantly lower in groups A-gauze and S-wool than in groups RT, SB-jet and U-sonic (p<0.001). Surface roughness was statistically lower in group S-wool compared to other groups (p<0.001). Static friction showed no statistical difference between cleaning methods (p>0.05).CONCLUSION: Retrieved SS archwires showed higher debris and surface roughness than asreceived, after four-weeks intraorally. A-gauze and S-wool were effective cleaning methods to control debris, but only S-wool has reduced surface roughness.

Efficacy of Home Washing Methods in Controlling Surface Microbial Contamination on Fresh Produce

2006 ◽  
Vol 69 (2) ◽  
pp. 330-334 ◽  
Author(s):  
AGNES KILONZO-NTHENGE ◽  
FUR-CHI CHEN ◽  
SANDRIA L. GODWIN
Keyword(s):  
Bacterial Contamination ◽  
Microbial Contamination ◽  
Tap Water ◽  
Fresh Produce ◽  
Listeria Innocua ◽  
Home Setting ◽  
Paper Towel ◽  
Cleaning Procedures ◽  
Cleaning Methods ◽  
Water Rinse

Much effort has been focused on sanitation of fresh produce at the commercial level; however, few options are available to the consumer. The purpose of this study was to determine the efficacy of different cleaning methods in reducing bacterial contamination on fresh produce in a home setting. Lettuce, broccoli, apples, and tomatoes were inoculated with Listeria innocua and then subjected to combinations of the following cleaning procedures: (i) soak for 2 min in tap water, Veggie Wash solution, 5% vinegar solution, or 13% lemon solution and (ii) rinse under running tap water, rinse and rub under running tap water, brush under running tap water, or wipe with wet/dry paper towel. Presoaking in water before rinsing significantly reduced bacteria in apples, tomatoes, and lettuce, but not in broccoli. Wiping apples and tomatoes with wet or dry paper towel showed lower bacterial reductions compared with soaking and rinsing procedures. Blossom ends of apples were more contaminated than the surface after soaking and rinsing; similar results were observed between flower section and stem of broccoli. Reductions of L. innocua in both tomatoes and apples (2.01 to 2.89 log CFU/g) were more than in lettuce and broccoli (1.41 to 1.88 log CFU/g) when subjected to same washing procedures. Reductions of surface contamination of lettuce after soaking in lemon or vinegar solutions were not significantly different (P &gt; 0.05) from lettuce soaking in cold tap water. Therefore, educators and extension workers might consider it appropriate to instruct consumers to rub or brush fresh produce under cold running tap water before consumption.

Susceptibility of Starved Planktonic and Biofilm Listeria monocytogenes to Quaternary Ammonium Sanitizer as Determined by Direct Viable and Agar Plate Counts

1993 ◽  
Vol 56 (7) ◽  
pp. 573-576 ◽  
Author(s):  
TYH-JENQ REN ◽  
JOSEPH F. FRANK
Keyword(s):  
Listeria Monocytogenes ◽  
Quaternary Ammonium ◽  
Phosphate Buffer ◽  
Benzalkonium Chloride ◽  
Agar Plate ◽  
Viable Count ◽  
Plate Count ◽  
Planktonic Cells ◽  
Plate Counts ◽  
Cleaning Procedures

Effective food plant cleaning procedures remove microbial nutrients from surfaces, which could result in contaminating bacteria being subject to a starvation microenvironment. This research investigated the effect of starvation on the susceptibility of Listeria monocytogenes to benzalkonium chloride (BAC). Cells were starved in phosphate buffer at 21°C for 4 d. Biofilm and planktonic listeriae reacted differently to starvation. When cells were grown in tryptic soy broth (TSB), starvation reduced the susceptibility of planktonic cells to BAC by 2.3- to 4.7-fold but had no effect on the susceptibility of biofilm cells. Planktonic cells grown in diluted TSB were 390 times more resistant than normal TSB-grown cells, but when these cells were starved, they lost their increased resistance. This phenomenon was not observed with biofilm cells. Increased resistance of listeriae grown in diluted TSB was associated with dilution of the salt/buffer components of the medium. Sanitizer-treated cells were enumerated by using tryptic soy agar-yeast extract pour plates and by a direct viable count method. Results indicate that some cells exposed to BAC were not detected by the plate count procedure but were still viable.

Influence of Usage History, Instrument Complexity, and Different Cleaning Procedures on the Cleanliness of Blood-Contaminated Dental Surgical Instruments

2009 ◽  
Vol 30 (7) ◽  
pp. 702-704 ◽  
Author(s):  
Gang Wu ◽  
Xuefen Yu
Keyword(s):  
Clinical Setting ◽  
Surgical Instruments ◽  
Cleaning Procedures ◽  
Cleaning Methods

Our study assessed the factors that influence the resistance of blood residues on dental surgical instruments to washer-disinfector-based cleaning procedures in a clinical setting. The use of 2 additional cleaning methods—presoaking and scrubbing by hand—and the use of newer and/or less structurally complex instruments significantly increased the efficacy of washer-disinfector cleaning.

Allergen Removal and Transfer with Wiping and Cleaning Methods Used in Retail and Food Service Establishments

2020 ◽  
Vol 83 (7) ◽  
pp. 1248-1260
Author(s):  
BINAIFER BEDFORD ◽  
GIRVIN LIGGANS ◽  
LAURIE WILLIAMS ◽  
LAUREN JACKSON
Keyword(s):  
Food Service ◽  
Food Environments ◽  
Food Contact ◽  
Food Contact Surfaces ◽  
Cleaning Procedures ◽  
Contact Surfaces ◽  
Cleaning Methods ◽  
Quaternary Ammonium Chloride ◽  
Flow Devices ◽  
Retail Food

ABSTRACT Preventing the transfer of allergens from one food to another via food contact surfaces in retail food environments is an important aspect of retail food safety. Existing recommendations for wiping and cleaning food contact surfaces is mainly focused on preventing microorganisms, such as bacteria and viruses, from contaminating foods. The effectiveness of these wiping and cleaning recommendations for preventing the transfer of food allergens in retail and food service establishments remains unclear. This project investigated (i) allergen removal from surfaces by wiping with paper wipes, terry cloth, and alcohol quaternary ammonium chloride (quat) sanitizing wipes; (ii) cleaning of allergen-contaminated surfaces by using a wash–rinse–sanitize–air dry procedure; and (iii) allergen transfer from contaminated wipes to multiple surfaces. Food contact surfaces (stainless steel, textured plastic, and maple wood) were contaminated with peanut-, milk- and egg-containing foods and subjected to various wiping and cleaning procedures. For transfer experiments, dry paper wipes or wet cloths contaminated with allergenic foods were wiped on four surfaces of the same composition. Allergen-specific lateral flow devices were used to detect the presence of allergen residues on wiped or cleaned surfaces. Although dry wipes and cloths were not effective for removing allergenic foods, terry cloth presoaked in water or sanitizer solution, use of multiple quat wipes, and the wash–rinse–sanitize–air dry procedure were effective in allergen removal from surfaces. Allergens present on dry wipes were transferred to wiped surfaces. In contrast, minimal or no allergen transfer to surfaces was found when allergen-contaminated terry cloth was submerged in sanitizer solution prior to wiping surfaces. The full cleaning method (wash–rinse–sanitize–air dry) and soaking the terry cloth in sanitizer solution prior to wiping were effective at allergen removal and minimizing allergen transfer. HIGHLIGHTS

Photocatalytic degradation of persistent organic pollutants under visible irradiation by TiO2 catalysts sensitized with Zn(II) and Co(II) tetracarboxy-phthalocyanines

2016 ◽  
Vol 20 (08n11) ◽  
pp. 1190-1199 ◽  
Author(s):  
Yaghub Mahmiani ◽  
Altuğ Mert Sevim ◽  
Ahmet Gül
Keyword(s):  
Photocatalytic Degradation ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Diffuse Reflectance Spectroscopy ◽  
Aqueous Media ◽  
Visible Region ◽  
Gas Chromatography Mass Spectrometry ◽  
Infrared Spectrometry ◽  
Visible Irradiation ◽  
The Difference

Photo-excitation under visible light has been an important step to acquire solar-driven TiO2 photocatalysts and dye sensitization has been used frequently to extend the optical response of TiO2 into the visible region. In the present work, new heterogeneous photocatalysts were prepared by anchoring carboxylic acid substituted Zn(II) and Co(II) phthalocyanines onto polycrystalline TiO2 surface and their photocatalytic activities were investigated. Due to covalent bonding of carboxy-terminated molecules onto TiO[Formula: see text]semiconductors, we synthesized symmetric 4-hydroxybenzoic acid-bearing metallophthalocyanines as dye sensitizer molecules. Heterogeneous composites having titanium dioxide and metallophthalocyanines anchored via CO–O–TiO2 bonds were characterized by using X-ray diffraction (XRD), Fourier-transform infrared spectrometry (FT-IR), and ultraviolet-visible diffuse reflectance spectroscopy. The optimum loading value of the dyes on TiO2 were 0.98 [Formula: see text]mol/g TiO2 for CoPc and 0.86 [Formula: see text]mol/g TiO2 for ZnPc, nearly independent of the amount of TiO2 used. These newly obtained heterogeneous photocatalysts were employed in the photocatalytic degradation of 4-chlorophenol(4-CP), chlorobenzene(CB) and 1,2,4-trichlorobenzen(TCB) in aqueous media under visible irradiation. Gas chromatography-mass spectrometry (GC-MS) was used for quantitation. The new photocatalysts showed excellent activities with visible-region irradiation in the photocatalytic degradation of persistent organic pollutants (POPs) as compared to the control experiments used with untreated TiO2 and the difference was attributed to the cooperation of the two elements, namely TiO2 and MPc. Experiments show that in two hours nearly complete degradation of POPs were observed.

Rapid Biomimetic Coating of Biocompatible Calcium Phosphate on Titanium: Influence of Pretreated NaOH Concentration and Cleaning Method

2015 ◽  
Vol 1119 ◽  
pp. 444-448 ◽  
Author(s):  
Faungchat Thammarakcharoen ◽  
Nattapat Hobang ◽  
Jintamai Suwanprateeb
Keyword(s):  
Calcium Phosphate ◽  
Sodium Hydroxide ◽  
Weight Change ◽  
Octacalcium Phosphate ◽  
Coating Process ◽  
Cleaning Method ◽  
Gel Layer ◽  
Biomimetic Coating ◽  
Coating Formation ◽  
Cleaning Methods

In this study, the influence of employing three different sodium hydroxide (NaOH) pretreatment concentration (1, 3 and 5M) and two cleaning methods (Ultrasonic or Rinse) used in rapid biomimetic coating process on phase composition, function groups, thickness, amount and microstructure of the resulted coating was carried out. Regardless of process parameters, x-ray diffraction and Fourier transform infrared spectroscopy revealed that the all coating mainly comprised octacalcium phosphate and hydroxyapatite as main phases while the microstructure similarly consisted of sharp and interconnected plate-like calcium phosphate (CaP) crystals vertically grown on the surface of titanium. However, the change in sodium hydroxide concentration in pretreatment step and cleaning method influenced the weight change after pretreatment, coating continuity and uniformity, but not the weight change after coating. This could be related to amount of the amorphous alkali gel layer formed during pretreatment step which influenced the rate of coating formation in rapid biomimetic coating process.

scholarly journals Cleaning Methods for Ceramic Ultrafiltration Membranes Affected by Organic Fouling

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 131
Author(s):  
Kamila Gruskevica ◽  
Linda Mezule
Keyword(s):  
Ceramic Membranes ◽  
Organic Liquids ◽  
Membrane Cleaning ◽  
Physical Methods ◽  
Operational Conditions ◽  
Organic Fouling ◽  
Cleaning Procedures ◽  
Cleaning Methods ◽  
Industrial Level ◽  
Selection Of

The use of ceramic membranes in the treatment and processing of various liquids, including those of organic origin, has increased tremendously at the industrial level. Apart from the selection of the most appropriate membrane materials and operational conditions, suitable membrane cleaning procedures are a must to minimize fouling and increase membrane lifespan. The review summarizes currently available and practiced non-reagent and cleaning-in-place methods for ceramic membranes that are used in the treatment of organic liquids, thus causing organic fouling. Backflushing, backwashing, and ultrasound represent the most often used physical methods for reversible fouling treatment. At the same time, the use of alkalis, e.g, sodium hydroxide, acids, or strong oxidants are recommended for cleaning of irreversible fouling treatment.

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