Indicators Fecal Coliform Research Articles

English

Water quality was assessed from 11 hand dug wells in the Adentan Municipality using Water Quality Index (WQI) and bacteriological load as indicators. The sampling was conducted during the months of July to September, 2019. A total of 33 samples were taken from 11 hand dug wells at monthly intervals. Weighted Average Water Quality Index (WAWQI) was used to compute parameters which include temperature, pH, conductivity, total dissolved solids, turbidity, total solids, biological oxygen demand, salinity and total alkalinity. Indicator fecal coliforms were also enumerated. All samples showed presence of E. coli and Salmonella in the dug wells with AD2 having the highest E. coli count of 1.32x103cfu/100 ml. AD11 had the least count of both E. coli and Salmonella (1.28x102 cfu/100 ml and 1.68x101 cfu/100 ml) respectively. The highest WQI value was recorded for AD7 and the lowest was recorded for AD9. 36.4% of the wells were graded as “A” whilst the remaining 63.6% were graded “B”. The combined results of WQI and bacteriological assessment shown that the water quality determined only by WQI (physico-chemical) parameters cannot reflect the true water quality status. Key words: Water quality index, bacteriology, weighted average water quality index, indicator.

Microbiological quality of packaged drinking water brands marketed in Minna metropolis, North Central Nigeria

The sale and consumption of packaged water is increasing by the day in Nigeria and this increase is attributed to the fact that there is inadequate supply of portable water in urban areas. This study investigated the bacteriological quality of packaged water at point-of-sale in Minna, North central Nigeria with emphasis on the incidence of pathogenic bacteria in samples tested. Twenty samples comprising 5 bottled and 15 sachet water brands purchased randomly all over Minna city were analyzed for presence of bacterial indicators of water quality. Standard microbiological procedures were used to investigate incidence of pathogenic bacteria such as Salmonella shigella and indicator faecal coliforms. Results showed that 60% of the sachet water samples examined were either untreated or produced under unhygienic conditions. However, all the bottled water analyzed tested negative to E coli, total coliform, Salmonella shigella and total bacteria count. Most of the sachet water brands fell below SON, NAFDAC and WHO drinking water standards and are therefore of doubtful quality. Efforts need being intensified in the monitoring of activities in this rapidly expanding industry with a view to raising standards of its purity for consumption.Nigerian Journal of Technological Research, vol 7(1) 2012

The Impact of Cattle Grazing in High Elevation Sierra Nevada Mountain Meadows over Widely Variable Annual Climatic Conditions

The impact of summer cattle grazing on water quality during three very different climatic years in the Sierra Nevada was investigated. Water year 2009 had near normal precipitation; 2010 had late precipitation and snowmelt; and 2011 had 150% above normal precipitation. Surface waters were tested for pathogenic bacteria indicators fecal coliform, E. coli, and total coliform before and after cattle were released onto summer grazing allotments. Water samples were collected from meadow stream sites up to 6 weeks before and up to 6 weeks after cattle grazing began. Streams passing through ungrazed meadow served as controls. Eight sample sites were between 1694 m and 2273 m in elevation; one site was lower at 1145 m in elevation. Samples were transported within 6 hours to a water analysis laboratory, where samples were analyzed following standardized laboratory methods. Results showed that individual site and total mean concentrations of E. coli in surface waters were within regulatory standards before cattle arrived during each of the 3 study years. After the beginning of grazing, mean E. coli counts increased as follows: 2009 from 8 to 240 CFU/100mL, 2010 from 7 to 561 CFU/10mL; 2011 from 7 to 657 CFU/100mL (p < 0.05 all years). Total coliform bacteria and fecal coliform concentrations showed the same pattern. This study shows that cattle grazing in the high elevation Sierra Nevada results in a significant increase in indicator bacteria. This impact on the watersheds occurs despite widely variable annual climatic conditions.

Removal of fecal indicator organisms and parasites (fecal coliforms and helminth eggs) from municipal biologic sludge by anaerobic mesophilic and thermophilic digestion

In this work, two egg-shaped, 5L-volume, anaerobic sludge digesters were used, one under mesophilic conditions (35 degrees C, M1), and the other under thermophilic conditions (55 degrees C, T1). Both digesters were fed with the purged sludge from an anaerobic treatment plant (start-up period) and from an activated sludge plant (stabilization period), treating municipal wastewaters. The purpose of the study was to establish the technical feasibility of the anaerobic thermophilic sludge treatment comparatively, during the stages of start-up and stabilization of the process, for removing pathogenic microorganisms and parasites efficiently. The results show that, in both stages, the anaerobic thermophilic digester presents higher efficiency on the removal of pathogens and parasites, than the mesophilic digester. Anaerobic thermophilic digestion is close to complying with the EPA (1998) limits for "Class A" type biosolids, referring to the number of parasitic helminth eggs (0.25 HELarval/gTS), and to the pathogen indicator fecal coliforms (< 1000 MPN/gTS). Therefore, the results show that thermophilic anaerobic digestion of biologic sludge may be considered as a suitable technology for the production of Class A biosolids, for further use in agriculture without restrictions.