Water quality has recently emerged as one of the utmost severe ecological problems being faced by the developing countries all over the world, and Bangladesh is no exception. Both surface and groundwater sources contain different contaminants, which lead to numerous deaths due to water-borne diseases, particularly among children. This study presents one of the most comprehensive reviews on the current status of water quality in Bangladesh with a special emphasis on both conventional pollutants and emerging contaminants. Data show that urban rivers in Bangladesh are in a critical condition, especially Korotoa, Teesta, Rupsha, Pashur, and Padma. The Buriganga River and few locations in the Turag, Balu, Sitalakhya, and Karnaphuli rivers have dissolvable oxygen (DO) levels of almost zero. Many waterways contain traces of NO3, NO2, and PO4-3 pollutants. The majority of the rivers in Bangladesh also have Zn, Cu, Fe, Pb, Cd, Ni, Mn, As, and Cr concentrations that exceed the WHO permissible limits for safe drinking water, while their metal concentrations exceed the safety threshold for irrigation. Mercury poses the greatest hazard with 90.91% of the samples falling into the highest risk category. Mercury is followed by zinc 57.53% and copper 29.16% in terms of the dangers they pose to public health and the ecosystem. Results show that a considerable percentage of the population is at risk, being exposed to contaminated water. Despite hundreds of cryptosporidiosis cases reported, fecal contamination, i.e., Cryptosporidium, is totally ignored and need serious considerations to be regularly monitored in source water.

Microbiological monitoring of river water quality is obligatory for use-related aspects such as drinking water production, irrigation and recreation. Assessment of the microbiological quality of water and sediment at the Velika Morava River was performed at five sites, during 2010 and 2011. By applying standard procedures for sanitary correctness and organic load assessment, total of 16 parameters were analyzed. Results of analysis indicated that microbiological water quality of the Velika Morava River is unsatisfactory.

Due to development in the science, especially in the area of biodegradation, it becomes clear that different species of aerobic and anaerobic bacteria are indigenous in the ground water. Due to changed condition in ground water, like infiltration of petroleum hydrocarbons, indigenous bacteria start to react and are involved in different processes of natural biodegradation. Also, great contribution of understanding how bacteria functionating in ground water is given from the field of well regeneration due to consequences of biofouling and biologically induced corrosion. In this article several natural processes related to bacteria are analyzed and its importance and distribution in ground water is shown.

This study aims to determine how vulnerable groundwater in Khartoum is to contamination. For this purpose, the DRASTIC Index idea was used. A descriptive cross-sectional analytical analysis is designed in this study. A total of 279 boreholes were sampled from a total of 1015 boreholes (27.5 percent). The following criteria were utilized to define the DRASTIC Index: depth, net recharge, aquifer media, soil texture, terrain, video media, and soil conductivity. Standard bacteriological test methodologies were used for groundwater. The biological data from the 279 boreholes revealed that total coliform, thermo-tolerant coliform, and E. coli were found in 34.4 percent, 18.6 percent, and 0.36 percent of the boreholes, respectively. Bacteriological contamination is common in Sharge Elnile, although only a few cases have been reported in Khartoum. According to the study, the bulk of boreholes in Khartoum State were built without any criteria. Many sources of contamination were discovered within a radius of less than 120 meters, which was deemed to violate Khartoum State’s Environmental Health Law of 2002. For this reason, bacteriological contamination is common in Sharge Elnile, although only a few cases have been reported in Khartoum.

Introduction of allochthonous species may have noticeable affects on populations communities of native species, ecosystem, but also could result in socio-economic consequences. Therefore, creating and applying risk assessment protocols of aquatic invasive species is a main step in supression of biological invasions. SBC index is used for estimation of biological contamination.

Biofilm naturally occurs in many water distributive systems. The aim of the paper is to determine biofilm forming potential of bacteria isolated from tap water from Novi Sad. A colometric crystal violet microtitre plate test was used to determine bacterial potential to form biofilm. The results show that some isolates have a great potential to form biofilm, especially when grow on higher temperature and in the reach nutritive media.

A survey of the incidence of Salmonella in samples collected from three treatment plants of sewage, food-poisoning, sporadic case with acute enteritis and healthy carrier in a local city, was performed from Aprile 1974 to December 1978. Salmonella were very frequently found in Influent sewage. The range of sewage source serovars found was wide and most aerovara were related with human source. A total of 954 strains and 62 serovars of Salmonella were found in sewage and human source. S. typhimurium, S.tennessee, S.thompson, S.infantis, S. senftenberg and S.oranienberg were the most frequent aerovars. It might be presumed that the environmental contamination of the area by the organisms is increasing gradually, since new aerovars of Salmonella, for example S.havana, S.agona, S.london, S. mission and S.cerro etc., which were never found in Nagano prefecture before, were isolated in the area. Effect of addition of the Aluminum sulfate and Polyacrylamide for Salmonella isolation from sewage, were studied. By use of the floe method. Salmonella were more frequently isolated from influent sewage.