Water Purification Stations Research Articles

Bacteriological and Physicochemical Studies on Tigris River Near the Water Purification Stations within Baghdad Province

We studied the physical, chemical, and microbiological factors that influence drinking water quality processed from River Tigris, and of the three main drinking water purification stations located at different parts of Tigris River, along with evaluation of drinking water of Al-Shula region in Baghdad city. Water samples were taken monthly from December 2009 to September 2010. Physical and chemical analyses of water included determination of temperature, pH, turbidity, electrical conductivity, total dissolved solids, salinity, dissolved oxygen, and biological oxygen demand. The results of water before and after purification indicated values within the international allowable levels. Microbial analyses included estimation of the number of total viable microbial counts, total coliform, total fecal E. coli and Pseudomonas aeruginosa, and other pathogenic bacteria that might be present in the water of the three stations and of the Tigris River, and also the tap water from Al-Shula houses. The results indicated that the types and proportions of various bacterial species isolated from different water sources were almost similar. This indicates inefficient purification procedures in all the stations studied, which exceeded the internationally allowable level of pathogens in potable water. Also, this explains the high incidence rate of children diarrheal reported in Al-Shula region.

Fatal hydrogen sulphide poisoning in unconfined spaces

Fatal hydrogen sulphide poisoning usually occurs in confined spaces. We report two fatal accidents in unconfined spaces. The first accident caused the death of three workers who entered an unconfined room in a silo of sludge at the same time that a truck dumped several tons of sludge from water purification stations. The hydrogen sulphide that had accumulated inside the silo spilled out into the interior of the room due to a 'splashing effect' caused by the impact of the dumped sludge. The second accident occurred when the foreman of a wastewater treatment plant entered one of the substations to perform routine checks and suddenly lost consciousness. Although he was rapidly transferred to an intensive care unit, death occurred a few hours later. Hydrogen sulphide production was, in this case, due to an 'embolism effect' produced by the displacement of wastewater when the substation pumps were activated. We suggest ways in which accidents such as these caused by sudden release of hydrogen sulphide can be prevented.

Measuring resistant forms of two pathogenic protozoa (Giardia spp and Cryptosporidium spp) in two aquatic biotopes in Yaoundé (Cameroon)

Organisms of the genera Cryptosporidium and Giardia are enteric parasites that are responsible for cryptosporidiosis and giardiasis respectively. They are characterised by profuse diarrhoea, abdominal pain and cramping. The symptoms can be fatal for immunodepressed subjects and children because these are opportunistic pathogens. These pathogenic infections are rampant in developing countries due to the unhygienic and improper disposal of wastewater and the use of surface water as the major sources of potable water. Little information is available about the resistant forms of these microorganisms in the hydrosystems of Cameroon in particular and other sub-Saharan ecosystems in general. The aim of this research was to isolate, identify, and measure these forms of these emerging protozoa in the waste and surface waters of Yaoundé, Cameroon. Giardia spp cysts were identified by Lugol iodine staining, and the Cryptosporidium spp oocysts by the Ziehl-Neelsen technique. The cysts were oval in structure and varied in length from 7 um to 12.0 um. Axostyles were visible along the median line and nuclei were present. The oocysts were round in structure and varied in diameter from 4 um to 6 um. A double cell wall was seen in the apicomplexa. The highest concentrations of Giardia spp cysts were 560 cysts/L in the surface water and 650 cysts/L in the residual effluent, while the corresponding figures for Cryptosporidium spp were 1,110 oocysts/L in the stream and 1,500 oocysts/L in the effluent. The cyst and oocyst counts were higher in the direct effluent because they are released directly into the wastewater by feces, while they are diluted in the surface water, reducing their abundance. Turbidity has a significant effect (p<0.05) on the population dynamics of these microorganisms, thereby indicating the importance of suspended or colloidal particles in the dissemination of these pathogens in aquatic media. The suspended particles in the wastewater adsorb the oocysts and cysts, probably because of the interactions between the electric charges carried by suspended particles and those present at the surface of the parasites. The positive correlation observed between these parasites and ammonia may account for some of the die-off of these resistant forms, because ammonium ions in water are known to inactivate trophozoites and sporozoites present in cysts and oocysts. This may be due to the permeability of the protozoan membrane to the ammonium ion and other alkaline earth metals present in aqueous form in the biotope. These parasite forms in these media represent a considerable health risk to the inhabitants of the study zone who depend on this surface water for drinking. The small size of these parasitic forms, the nonfunctional water purification stations and ineffective water treatment systems expose the community to outbreaks of giardiasis and cryptosporidiosis.

Norovirus foodborne outbreaks associated with the consumption of oysters from the Etang de Thau, France, December 2002.

In January 2003, the Institut de Veille Sanitaire received notification of clusters of gastroenteritis (GE) thought to be associated with consumption of oysters harvested from Etang de Thau in the south of France. At the same time Italy reported an outbreak (200+ cases) associated with oysters from the Etang de Thau. An investigation was carried out to determine the source and vehicle of the outbreaks. Descriptive analysis of reported clusters in France, microbiological analysis of stool and oyster samples, genotyping of noroviruses and an environmental investigation of the Etang de Thau were carried out. A retrospective cohort study was also undertaken among those attending a number of family meals in Paris. Thirteen family clusters in four districts of France (69 cases) could be attributed to the consumption of Thau oysters based on descriptive evidence. Oysters distributed at an office in Paris and consumed at fourteen family meals between 19 and 24 December led to a further outbreak. In this outbreak the attack rate was 21/36 (58%) for Thau oyster consumers and 0/22 for non-consumers (p=0.00002). Noroviruses (genogroups I and II) were found in stool samples from four clusters and oysters from three clusters (including Paris). Environmental investigations revealed heavy rainfall, an overflow of a water purification station and faecal contamination of the Etang de Thau in December. Oysters from the Etang de Thau were responsible for a number of clusters of norovirus GE in winter 2002 in France and also in Italy. High Escherichia Coli levels in Thau water and shellfish led to an official request, mid-December, for oyster purification before distribution. This was not possible, due to lack of purification facilities. This investigation has contributed to a change in the way that shellfish harvesting areas are classified in France.

Investigation of possibility of semiconductor sensor usage for controlling air state of biological water purification station

The sensors based on SnO 2 doped by Sb have been produced and investigated in this project in order to determine CH 4 and H 2S concentrations in the air environment of biological purification stations. The sensor sensitivity to methane has been increased via platinum added into the sensor. H 2S interference while measuring CH 4 has been excluded with the sample's drawing through a substance absorbing H 2S. While modeling the process of waste water anaerobic bio-purification, it was estimated that CH 4 concentration has not been hazardous while H 2S has exceeded the ultimate level of the working zone. The work depicts the necessity of water bio-purification stations air control and the possibility of performing it via the sensors.

Chemometrical analysis and quality control of pot water and its sources from Athens, Greece

The present study describes a chemometrical interpretation of a large data set from pot water quality control results. Sixteen chemical and physicochemical parameters constantly checked throughout the year were involved in the classification procedure. The data originate from seventeen sampling stations (pot water sources and pot water purification stations) and were collected in the period January ‐December 1993. Mean values for two months periods were introduced to the chemometrical procedure, so finally a data set 101x16 was formed. Additionally, quality control requirements of the European Union for pot water were added to the set to form an information input matrix of 103x16 elements. Hierarchical and non‐hierarchical clustering procedures were applied in order to reveal the internal structure of the data set. Some interesting conclusions like special water quality of lake Mornos, possibility of quality monitoring with lesser number of components etc., concerning the quality and stability of the pot ...

Une impulsion à la planification territoriale concertée : le plan du Delta du Llobregat

The Llobregat Delta, in the immediate proximity of the greater Barcelona city area, consitutes a strategic enclave for metropolitan development. This flat, not overly-developed area is situated at the meeting point of two natural axes of activity, the coast and the Llobregat River basin. The Barcelona airport is located here, along with the site of the future extension of the port and also a large number of the basic networks of various means of transportation. In this article is described the planning process which has been followed in this zone, under the stimulus of the Ministry of Public Works, Transport and Environment, which holds title to most of the infrastructures here. With the object in mind of transforming the Delta into a logistic platform on a European level, planning has taken into account the roles to be played by each of the territorial Bureaus: the Généralité of Catalonia, as the entity responsible for town and country development; and the Mayors and the Regional Council, which have historically been opposed to isolated sector-based activities and destruction of the environment. The Infrastructure Plan for the Llobregat Delta, which is both concerted and global, is organizing the development of the Port along with the consolidation of a zone of logistic activities, the detour of the river into its final segment, the future extension of the airport, new highway and train access routes into the area, the development of the coastal areas, conservation of natural resources, a water purification station, an incinerating plant, and so on. This project is being concretized into a proposition for a contract among several government offices, and will include programming over time the various actions to be taken and the financial compromises necessary.

Seasonal changes of bacterial counts and bacterial species in Nile River water at two water purification stations in Cairo.

Seasonal estimations of viable bacterial counts (VBC) were performed for Nile River water at two water purification stations during the year 1981-1982 using 5 different enumeration media at 30 or 55°C. In general, the counts varied with the depth, season, locality, enumeration medium and temperature of incubation. Identification of 146 bacterial strains isolated from the different enumeration plates revealed the presence of 14 genera covering 21 species. Suggestions were made to protect the Nile River water from the pollution caused by human waste and sewage.