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Introduction. Objectives: Check water distribution system in the university and determine contaminated point in the system to be treated. Suggest appropriate treatment to eliminate the possible contamination. Introduction. Limitation of the Study:
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Introduction • Objectives: • Check water distribution system in the university and determine contaminated point in the system to be treated. • Suggest appropriate treatment to eliminate the possible contamination
Introduction • Limitation of the Study: • To investigate drinking water distribution system in Islamic University by detection of primary indicator pathogenic bacteria of 220 sample and perform three chemical tests including dissolved oxygen, nitrate and chloride on each sample and PH measurements as physical parameter
Introduction of water contaminations Microbial contamination • There are four main typesof micro organism that can contaminate drinking water: • Bacteria • Virus • Protozoa • Fungi
Bacterial Contamination • Water borne Disease can caused by different type of bacteria. • Most of bacterial pathogen may found in distribution system illustrate in this table.
Virus Contamination Water may also play a role in the transmission of virus with different mode of action such as: Hepatitis A and B virus, Rotavirus and others. • Others include: • Poliovirus : poliomyelitis • Enteric adenoviruses: gastroenteritis • Hepatitis E : liver inflammation
Protozoa Contamination: Giardia lamblia, cryptosporidium parvumandEntamoeba histolytica are the major intestinal protozoal pathogens that contaminate drinking water.
Primary Indication of Contamination Total coliform bacteria The organisms most commonly used as primary bacterial indicators of faecal pollution are the coliform group which . are: • Member of Family Enterobacteriace. • Non spore forming bacteria • Can ferment lactose at 35-37ºC
Total coliform bacteria • The total coliform bacteria group includes both faecal and environmental species which include: • Escherichia coli. • Citrobacter. • Klebsiella. • Enterobacter.
Bacterial fecal indicator should be: • Abundant in faeces and sewage. • Absent or at least very small in • number from all other sources. • Capable of isolation and identification easly.
Total coliform bacteria • These Organisms can survive and grow in water distribution system, they can be used as: • Indictor of treatment effectiveness. • To assess the cleanliness and integrity of distribution system and the potential presence of biofilms.
Faecal coliform • E. coli is the predominant coliform in faeces and the only member of the coliform group exclusively associated with faeces. • Other organisms can also be used as indicator of faecal pollution such as: • Faecal streptococci. • Clostridium perferingens.
Biofilm in Distribution System • Many different microbes have demonstrated the ability to survive in the distribution system with some possessing the ability to grow and produce biofilms. • Water distribution system biofilm is a complex mixture of microbes organic and inorganic material accumulated amidst a microbially produced organic polymer matrix attachedto the inner surface of the distribution system.
Steps of biofilm development: • Trace organic material deposits on water/solid interface forming conditioning layer which allow initial attachment of material cell. • Planktonic (free floating) bacteria approach the pipe wall and become entrained with in the boundary layer where flow velocity falls to zero result in reversible adsorption.
Some of reversibly adsorbed cells may permanently adhere the cell to the surface and become irreversibly adsorbed. • Biofilm bacteria excrete extra cellular polymeric substance (sticky polymers) which : • Hold the biofilm together. • Act as nutrients for bacterial growth. • Protect bacteria from biocides.
Chemical contaminationchemical contaminant of drinking water are often considered a lower priority than microbial contaminants. • Nitrate: • Excessive concentration of nitrate in drinking water can be hazardous of health, especially for infants. • Methmoglobinemia result from high concentration of nitrate. Major chemical contaminant:
Chloride • Chloride in drinking water is generally not harmful to human beings until high concentration are reached, although it may be harmful to some people suffering from heart or kidney disease • Other health effect chemical contaminants: • Fluoride • Sodium • Arsenic • Lead
Literature review Treatment of water contamination. Sanitization Method Of bacteria Oxidizing biocides Non oxidizing biocides - Chlorine - Chlorine dioxide - Ozone • Quaternay • ammonium compounds. • - Anionic and nonionic surface active agent. Physical Treatment --- Heat - Mechanical removal
Methodology This is microbiologically and chemically study to detect the quality of water distribution system.
Methodology Distribution of samples:
Methodology Sampling collection Collection of sample is vary depend on the type of the source of water . Sampling from Taps - Flaming the tap by 70% ethanol saturated cotton swab. - Water was allowed to run for at least 2-3 minutes in order to flush refrigerator for sample collection
Methodology Reservoirs Sample Collection - Sterilization of outer surface of bottle by 70% ethanol -Dipping of sterilized bottle inside reservoirsusing long forceps.
Methodology Well Sample Collection - Collection from well was performed after sterilization of nearest tap water before water passes into reservoirs. Central Filter Sample Collection - Sterilization of plastic tap filterwith 70% ethanol. - Water were allowed to run for 5 minutes before the sample was taken.
Methodology Microbiological analysis Media and Reagent - Nutrient Agar -Endo-media Total plate count analysis - 100µl of sample were spread on NA by L- shaped glass rod. - Incubation at 37C for 24 hr before counts was done. - Colonies were counted as CFU/100ml.
Methodology Total Coliform Membrane Filtration Method: • Filtration of 100 ml water sample on membrane filter. • Picked up filter paper on specified media. • - Incubation at 37C for for 24hr
Methodology - Pink colony counted as presumptive total coliform. - Green metallic colony counted as presumptive E.coli.
Methodology Chemical and Physical Analysis Nitrate Analysis Ultraviolet spectrophotometric method used for nitrate determination. Chloride Analysis Silver nitrate titration was performed to determine chloride concentration as mg/l. silver nitrate titration for chloride determination
Methodology PH Measurement Using pH meter Dissolved Oxygen Using DO meter
Microbiological analysisTotal plate count (TPC) • The range of TPC in tested samples varied from as low as 1000CFU/100ml to TNTC ,with the exception of 14 samples which did not show any growth. • TPC value increased were water flow from main sources to finished taps.
Total plate count (TPC) • Some pathogenic bacteria with distinctive appearance were isolated and defined from some samples, such as Serratia and Pseudomonas auroginosa Red colonies of Serratia were observed on NA in filter reservoir sample
Total plate count (TPC) Green colony of Pseudomonas auroginosa observed on NA in different samples
Total plate count (TPC) • It observed that highest levels of TPC correlated with the age of building; older building such as (teeba, admission, medical service, student and academic affairs buildings) showed higher levels than new building.
Total plate count (TPC) • During the study period, some reservoirs in these building were found open or their cover not completely secure which indicate that there is a shortage of inspection to prevent such contamination that may result from dust or other sources (e.g., animals, insects and birds).
Total coliform (TC) • Samples collected showed that approximately 76% were contaminated with total coliform with a range varying from one CFU/100ml to TNTC. The rest of the samples (24%) were negative for Total coliform.
Total coliform (TC) • 23% of all reservoirs sample were contaminated with TC • 100% of all filter reservoir samples were contaminated with TC • 33%of all municipality reservoir samples were contaminated with TC
Total coliform (TC) • Highest main sources contamination observed in well. The following table illustrate total coliform levels in the three main sources in the university during the study period.
Total coliform (TC) • 80% of refrigerator samples were contaminated with Total coliform, and only 20% of samples were negative for TC.
Chemical analysisChloride • It observed that: • 93% of municipality samples did not comply with WHO standard, it exceeded 250mg/l • The following table summarize the result for filter and mun samples
Chloride • Lowest percentage failure chloride were found in N and D building, while highest percentage failure were found in E and C building. • Central filter has the ability to decrease 70% of chloride concentration from the main sources
Nitrate analysis: • The efficiency of central filter to decease nitrate concentration is about 40%. 1: mean of reservoir before filtration. 2: central filter, 3: mean of reservoir after filtration, 4: filter out let (kitchen) D500 5:D400, 6:D300, 7:D200, 8:D100, 9:D000
Nitrate analysis: • Summarize of nitrate result for filter and municipality samples illustrate in this table:
PH • For all samples were tested for PH measurement, results were showed in normal range according to Palestinian standard (6.5-8.5). • Summary of pH result for filter and mun samples
Dissolved oxygen • Dissolved oxygen measurement results were showed significant change for all samples, and this variation may be due to change in temperature during study period. • Normal range for DO is (6-8ppm) • summary of DO result for filter and municipality samples
