Sonja Šostar-Turk

Good quality printing with reactive dyes using guar gum and biodegradable additives

In printing with reactive dyes sodium alginates or synthetic thickeners are typically used as thickening agents to prevent unacceptable fabric handle. A new reactive printing process for reactive dyes on cellulosic textiles has been developed using natural thickening agents and environmental-friendly additives. Printing trials with guar gums have shown that the use of different additives can prevent fabric stiffness. These additives have no significant influence on rheology and colour strength but contributed to soft fabric handle even when guar gums were used as thickening agent. The use of additives and guar gum provide good quality prints with reduced wastewater pollution.

Efficiency of four sampling methods used to detect two common nosocomial pathogens on textiles

Detecting microorganisms on textiles is useful for many purposes, for example to determine the bioburden before laundering, assess the reduction in bacterial counts in connection with various laundry processes, or trace transfer routes in infection control investigations. Therefore a validated, reproducible and rational method is needed. For sampling microorganisms on textile surfaces the most commonly used method is the contact plate method using RODAC plates, first described by Hall and Hartnett followed by the swab sampling technique. Both methods can only capture microorganisms on the surface of the textiles while microorganisms that have penetrated into the deeper structure of the material will not be detected. In our research the contact plate method and the swabbing technique were compared with two wash-off methods. For the first wash-off method the destructive elution method was used, where microorganisms were eluted from the fabrics by shaking the fabrics for a certain time in an elution medium. For the fourth sampling method a nondestructive method that included a compact test device called Morapex® was used, which is based on forced desorption by pressing the microorganisms through the fabric without destroying the fabric. In our research, two types of microorganisms were included (Klebsiella pneumoniae and Staphylococcus aureus) that cause common nosocomial infections. The aim of this study was to compare the efficiency of the four sampling methods for detecting microorganisms on textiles and to determine the lowest concentration, which can still be detected. The percentage of microorganisms that were detected by both elution methods was substantially higher than by sampling of fabrics with the contact plate method or swabbing. It can be concluded that a nondestructive method using a modified Morapex® device can be applied for quick determination of the hygienic condition of textiles.

Determining the disinfection of textiles in compressed carbon dioxide using various indicator microbes

Aims:  This paper presents a research on the disinfection efficiency of inoculated textile swatches by compressed carbon dioxide, an environmental friendly way to disinfect textiles as opposed to the conventional laundering procedures using water. The disinfection efficiency was determined by using the following microbes inoculated on cotton test fabrics: Enterococcus faecium, Enterobacter aerogenes and Candida albicans.

Environmental Risk Factors in Connection with Hospital Laundry Effluent

This chapter presents research findings on how to optimize a washing process to reduce the effluent burden of hospitals thus achieving a more sustainable laundering procedure. Water is used in large quantities in laundries and currently they are producing relatively high quantities of wastewater. Effluent control is especially important in hospitals where potentially pathogenic microorganisms are present. A program for hospital bed linen was investigated and the first steps of optimization were performed. The disinfection effect of the laundering procedure was determined using standard bioindicators Enterococcus faecium and Staphylococcus aureus. The washing quality was also determined by measuring the parameters of the RAL-GZ 992 criteria for hospital textiles and the effluent quality was determined by measuring the parameters in the waste water according to the Slovenian regulations for concentration limits of emission into water or waste water treatment plants for waste water from laundries and dry-cleaners, published in Slovenian Official Gazette in 2007 (Uredba o emisiji snovi pri odvajanju odpadne vode iz naprav za pranje in kemicno ciscenje tekstilij 2007). The disinfection effect and washing quality were both attained in the optimized program. However due to higher concentrations of laundering agents the quality of the waste water was reduced after optimization of the program. Therefore the effluent waste water treatment for water reuse remained necessary.