The effect of active charcoal filter on viability of bacteria isolated from the tap water in Sarajevo

Clean water is essential to our existence and problems might arise when it becomes contaminated with different pathogens, which might pose a threat to human health. Tap water is generally considered drinkable since it passes different forms of disinfection during processing. Some households have additional disinfection procedures, the most common one being the usage of charcoal filters, in order to further clean the tap water from both undesirable solvents and microorganisms. In the first independent study of this kind, we have tested tap water for bacteria from five different locations in Sarajevo, and we have tested the efficiency of charcoal filter in trapping of bacteria. According to regulations in Bosnia and Herzegovina, there should be 1 colony forming unit (CFU) per 50ul of water sample, which was satisfied in only one location from Sarajevo, while one had significantly higher levels (6.7, p val. 0.0148). Overall, the charcoal filter has decreased the number of bacteria in the water, with the exception of one sample.

Penurunan Bakteri Coli pada Air Sungai Martapura Menggunakan Saringan Arang Sekam Padi

The Decrease in the Number of Coli Bacteria in Water of Martapura River Using The Husk Charcoal Filter. The habits of the people along the Martapura river, defecates into the river, causing the river water polluted by Coli bacteria that be able to cause disease. Water treatment is required to improve the water quality of the Martapura river, one of them is using "the husk charcoal filter " to obtain clean water that meets health requirements. This study aimed to analyze the effectiveness of the husk charcoal filter, and determine the thickness of the filter were most effective to decrease the number of coli bacteria in water of Martapura river. In this design, was performed the initial measurements (pretest), performed the treatment and performed the second measurement (posttest), so it could be seen the effectiveness of the treatment. The "husk charcoal filter" was effective to Decrease the Number of Coli Bacteria in the water of Martapura river as much as 69,2% - 99,3%. However, a decrease in the number of coli bacteria still above the standards required by the Water Quality Standard class B, after filtration. Because it still found much bacteria after filtering, it is advisable to boil water to boiling before consumption, because heating is the most effective way to kill microbial pathogens that be able to cause disease. Keywords: Water of Martapura River; coli bacteria; the husk charcoal filter.

The Effect of Cigarette Design on the Content of Phenols in Mainstream Tobacco Smoke

The influence of cigarette design on the content of phenols in mainstream tobacco smoke was studied. The most abundant phenols - catechol, hydroquinone, phenol, o-, m-, and p-cresol, and resorcinol - were determined by HPLC with fluorescence detection. Hydroquinone and catechol made the most significant contribution to the total content of phenols with maximum values of 135.0 µg/cig and 95.7 µg/cig, respectively. The highest total content of phenols (330.9 µg/cig) was measured in the smoke of a Virginia tobacco cigarette. The total content of phenols (µg/cig) in cigarette mainstream smoke decreased linearly with increased filter ventilation, R2 = 0.9536. The results obtained indicate that filtration and ventilation can strongly influence the mainstream tobacco smoke content of phenol and its less polar derivatives, o-, m-, and p-cresol, which were reduced by up to 85%. Hydroquinone and catechol are less affected and only cigarettes with the special “recessed charcoal filter system” and cigarettes with filter ventilation over 50% showed significant reductions. On a per mg ‘tar’ basis the largest contributor to phenols in cigarette mainstream smoke was the selection of the tobacco type. The use of any standard commercial filter on an unfiltered cigarette can substantially reduce the yield of phenols in cigarette mainstream smoke. The use of special filters (e.g., the “recessed charcoal filter system”) or high levels of cigarette ventilation does not reduce the amount of phenols in tobacco smoke considerably when normalized on a per mg ‘tar’ basis.