Treatment of Clinical Solid Waste Using a Steam Autoclave as a Possible Alternative Technology to Incineration

Abstract

A steam autoclave was used to sterilize bacteria in clinical solid waste in order to determine an alternative to incineration technology in clinical solid waste management. The influence of contact time (0, 5, 15, 30 and 60 min) and temperature (111 °C, 121 °C and 131 °C) at automated saturated steam pressure was investigated. Results showed that with increasing contact time and temperature, the number of surviving bacteria decreased. The optimum experimental conditions as measured by degree of inactivation of bacteria were 121 °C for 15 minutes (min) for Gram negative bacteria, 121 °C and 131 °C for 60 and 30 min for Gram positive bacteria, respectively. The re-growth of bacteria in sterilized waste was also evaluated in the present study. It was found that bacterial re-growth started two days after the inactivation. The present study recommends that the steam autoclave cannot be considered as an alternative technology to incineration in clinical solid waste management.

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“…[31] The entire test tube contains sterilized media before adding the sample, using an autoclave with a temperature of 121°C for 15 min. [32] After sterile, each medium is filled with samples. Then, the entire test tube is closed using cotton swabbed cloth.…”

“…The goal is that the supply of air, materials, equipment, and personnel can be controlled in such a way that microbial contamination remains at an acceptable level. [32] The reaction tube contains the media, and the sample is incubated with 37°C. Calculations were performed after bacteria were cultured for 48 h [ Calculations were performed after bacteria were cultured for 48 h. Coliform group bacteria showed positive results by generating bubbles of gas in Durham tube at 37°C, [33] while the fecal coliform bacteria would produce gas bubbles at 44°C [30] [ Table 2].…”

Stabilizate from Autoclaved Municipal Solid Waste as a Source of Valuable Humic Substances in a Waste Circular Economy

“…The constantly increasing amount of municipal solid waste and the implementation of directives regarding the reduction of the amount of waste that is landfilled has led to a search for new solutions that allow for maximal recovery and reuse of waste. One of the solutions may be autoclaving, which so far was applied mainly for medical waste [1][2][3][4]. In last decade a few autoclaving installations were established for municipal waste.…”

Utilização De Gás Ozônio Na Desinfecção De Resíduos De Serviços De Saúde

“…Diante dos riscos potenciais que o manejo inadequado dos resíduos de serviços de saúde representa a saúde humana e animal, assim como ao meio ambiente, existe um interesse crescente em identificar uma tecnologia confiável para o manuseio e descarte seguro destes resíduos, entretanto podem ser garantidos poucos métodos de tratamento que permitam eliminar todos os agentes infecciosos. Os processos de tratamento envolvem a destruição ou inativação irreversível de todos os patógenos presentes e a prevenção da recontaminação subsequente ou reinfecção com organismos patogênicos (ZHANG et al, 2007;ALAGÖZ, KOCASOY, 2008;OLIVEIRA et al, 2010;HOSSAIN et al, 2012;MARTINS et al, 2015;MARTINELLI et al, 2017).…”

“…O processo danifica termicamente a estrutura celular bacteriana, incluindo a membrana externa e citoplasmática, tornando a célula não mais viável (TORTORA et al, 2012). A inativação dos mecanismos vitais das células bacterianas depende da estrutura celular bacteriana, da temperatura e da duração da submissão ao calor a que estão expostos (HOSSAIN et al, 2012).…”