Tested Water Samples Research Articles

The quality of groundwater in rural areas and its impact on the functioning of local water intakes

The main purpose of this paper is to indicate the impact of changes in the quality of groundwater intakes on the functioning of rural water supply systems. In particular, the important factors for the groundwater quality in rural areas have been presented. Results of research on the quality parameters of groundwater, obtained in 2012 ÷ 2016 for selected small water intakes in north-western Poland, were presented. The quality of groundwater in the subsequent analyzed years was deteriorating. There was an increase in the content of iron and manganese compounds, ammonium ions, as well as the presence of bacteriological contaminants in test water samples. For these reasons, problems with providing the receivers with water of appropriate quality parameters have been reported in described rural intakes. The paper is an attempt to show the relationship between the type and magnitude of changes in the quality of groundwater and the efficiency of the treatment plant. In addition, pro-quality activities undertaken by local water companies were emphasized.

Effectiveness of Groundwater Treatment for Drinking Use and Dairy and Food Processing

Groundwater supplies should undergo comprehensive water quality testing to ensure suitability for drinking water and dairy production purposes Evaluation of chemical characteristics and microbiological quality as well as treatment processes applied for the removal of contaminants from ground water extracted from Al-Sag aquifer in Buraydah, Qassim region were investigated. The tested water samples from both well sources and effluents were found to have total dissolved solids, electrical conductivity and turbidity values within the acceptable limits of Saudi standards and WHO guidelines. Of course, the reduction percentages were the same for EC and TDS (58.6-93.6%) while it scored 0.0-100% for turbidity due to the adopted treatment processes. Chemical characteristics such as total alkalinity, chloride, nitrate and hardness were also found to be within the permissible levels of both Saudi standards and WHO guidelines. The effectiveness of the adopted treatment processes led to decrease such chemical parameters percent in the treated groundwater by about 54-82.9, 56.9-82.6, 29.0-95.8 and 7.9-98.2%, respectively. Moreover, mineral contents such as iron and cadmium in both raw and treated groundwater were below the detection limit. Groundwater contained fluorine at low levels than permissible limits set by local and international standards; therefore, fluoridation process must be taken into consideration for drinking use. Zinc content of the treated water was within the allowed concentration required by the Saudi standards and the WHO guidelines. While, nickel and lead contents in three groundwater sources were found to be higher than those postulated and recommended by the Saudi standards and WHO guidelines. However, water treatment at all studied stations was fair enough to remove these hazards and secure water. In regards to microbiological quality, the treated groundwater was found to be totally free from coliform organisms with almost undetectable level of viable count rendering them quite safe for drinking use and dairy-food processing.

Monitoring of heavy metals in selected Water Supply Systems in Poland, in relation to current regulations

The study presents an analysis of water quality monitoring in terms of the content of heavy metals, which is conducted in three independent water supply systems in Poland. The analysis showed that the monitoring of heavy metals isn't reliable - both the quantity of tested water samples and the location of the monitoring points are the problem. The analysis of changes in water quality from raw water to tap water was possible only for one of the analysed systems and indicate a gradual deterioration of water quality, although still within acceptable limits of legal regulations.

Fast, sensitive and reliable multi-residue method for routine determination of 34 pesticides from various chemical groups in water samples by using dispersive liquid\u2013liquid microextraction coupled with gas chromatography\u2013mass spectrometry

A simple and efficient dispersive liquid-liquid microextraction technique (DLLME) was developed by using a mixture of two solvents: 40 μL of tetrachlorethylene (extraction solvent) and 1.0 mL of methanol (disperser solvent), which was rapidly injected with a syringe into 10 mL of water sample. Some important parameters affecting the extraction efficiency, such as type and volume of solvents, water sample volume, extraction time, temperature, pH adjustment and salt addition effect were investigated. Simultaneous determination of 34 commonly used pesticides was performed by using gas chromatography coupled with mass spectrometry (GC-MS). The procedure has been validated in order to obtain the highest efficiency at the lowest concentration levels of analytes to fulfill the requirements of regulations on maximum residue limits. Under the optimum conditions, the linearity range was within 0.0096–100 μg L−1. The limits of detection (LODs) of the developed DLLME-GC-MS methodology for all investigated pesticides were in the range of 0.0032 (endrin)–0.0174 (diazinon) μg L−1 and limits of quantification (LOQs) from 0.0096 to 0.052 μg L−1. At lower concentration of 1 μg L−1 for each pesticide, recoveries ranged between 84% (tebufenpyrad) and 108% (deltamethrin) with relative standard deviations (RSDs) (n = 7) from 1.1% (metconazole) to 11% (parathion-mehtyl). This methodology was successfully applied to check contamination of environmental samples. The procedure has proved to be selective, sensitive and precise for the simultaneous determination of various pesticides. The optimized analytical method is very simple and rapid (less than 5 min).Graphical abstractAnalytical procedure for testing water samples consists of dispersive liquid-liquid microextraction (DLLME) and gas chromatography coupled with mass spectrometry (GC-MS).

Assessment of Irrigation Quality of Disposal Water of Ashuganj-Polash Agro-Irrigation Project, Brahmanbaria Bangladesh

The study was conducted at Ashuganj-Polash agro-irrigation project (APAIP), Brahmanbaria,aim to determine the chemical properties of power plant disposal water and to assess its suitability for irrigation. Initial soil samples (before irrigating crop field) and final soil samples (after crop harvesting) were collected. During irrigation ten water samples (six from crop field and four from irrigation canals) were collected for analysis. All soil samples were analyzed in Humboldt soil testing laboratory and water samples in bio-chemistry laboratory of Bangladesh Agricultural University and compared to FAO irrigation standard. Results show thatthe sodium absorption ratio (SAR) (0.53 to 0.88), residual sodium bi-carbonate (0.8 to 1.3meq L-1), Kelly’s ratio (0.31 to 0.6) and total hardness (85 to 150) found in normal range and largely suitable for irrigation. Soluble sodium percentage values found in satisfactory (20.26 to 41.1) level and magnesium absorption (57.1 to 76.4) found unsuitable for irrigation. Statistically similar value of pH, EC, total nitrogen, organic carbon, calcium, magnesium and phosphorus in initial and final soil sample were observed. But potassium and sulfur value reduced in final soil sample from initial soil. The water samples fall within the permissible limit and found suitable for crop production

A prolonged, community-wide cholera outbreak associated with drinking water contaminated by sewage in Kasese District, western Uganda

BackgroundIn May 2015, a cholera outbreak that had lasted 3 months and infected over 100 people was reported in Kasese District, Uganda, where multiple cholera outbreaks had occurred previously. We conducted an investigation to identify the mode of transmission to guide control measures.MethodsWe defined a suspected case as onset of acute watery diarrhoea from 1 February 2015 onwards in a Kasese resident. A confirmed case was a suspected case with Vibrio cholerae O1 El Tor, serotype Inaba cultured from a stool sample. We reviewed medical records to find cases. We conducted a case-control study to compare exposures among confirmed case-persons and asymptomatic controls, matched by village and age-group. We conducted environmental assessments. We tested water samples from the most affected area for total coliforms using the Most Probable Number (MPN) method.ResultsWe identified 183 suspected cases including 61 confirmed cases of Vibrio cholerae 01; serotype Inaba, with onset between February and July 2015. 2 case-persons died of cholera. The outbreak occurred in 80 villages and affected all age groups; the highest attack rate occurred in the 5–14 year age group (4.1/10,000). The outbreak started in Bwera Sub-County bordering the Democratic Republic of Congo and spread eastward through sustained community transmission. The first case-persons were involved in cross-border trading. The case-control study, which involved 49 confirmed cases and 201 controls, showed that 94% (46/49) of case-persons compared with 79% (160/201) of control-persons drank water without boiling or treatment (ORM-H=4.8, 95% CI: 1.3–18). Water collected from the two main sources, i.e., public pipes (consumed by 39% of case-persons and 38% of control-persons) or streams (consumed by 29% of case-persons and 24% control-persons) had high coliform counts, a marker of faecal contamination. Environmental assessment revealed evidence of open defecation along the streams. No food items were significantly associated with illness.ConclusionsThis prolonged, community-wide cholera outbreak was associated with drinking water contaminated by faecal matter and cross-border trading. We recommended rigorous disposal of patients’ faeces, chlorination of piped water, and boiling or treatment of drinking water. The outbreak stopped 6 weeks after these recommendations were implemented.

PHYSICO-CHEMICAL AND BACTERIOLOGICAL COMPOSITION IN A METROPOLITAN DRINKING WATER DISTRIBUTION SYSTEM IN KATHMANDU

The study was concentrated on water quality appraisal in metropolitan drinking water distribution system in Kathmandu during 2011 to 2015 AD. The study covers 24 research areas from surface water sources, treatment plants, processing and water supply networks of public, private and community drinking water suppliers in the main city of Kathmandu valley. Water quality was analyzed under six physical, seventeen chemical and two bacteriological parameters. All tests were conducted in accordance with the procedures laid down in the Standard Methods. Total 320 samples collected during two years of periods. The physico-chemical parameters of tested water samples from sources, reservoirs and taps were found to be within the range of National Drinking Water Quality Standard (NDWQS). The turbidity and pH values for most of the tested water samples from sources, reservoirs and taps except for a few source and tap samples were found to be within the NDWQS guideline values. The chemical parameters values of majority of tested source water samples were below the maximum level. The values of iron, manganese, sodium and chloride content of some source samples were found higher than the maximum permissible level recommended by NDWQS and WHO guideline. Bacteriologically, larger proportion of water samples (sources, reservoirs and taps) were found to be unacceptable. The present study disclosed fecal contamination to be the major problem in drinking water from source to the distribution for city water supply systems in selected metropolitan areas. The physico-chemical qualities of water in most cases were within acceptable limit.Journal of Institute of Science and TechnologyVolume 22, Issue 1, July 2017, page: 159-164

Effects of chlorine and hydrogen peroxide sanitation in low bacterial content water on biofilm formation model of poultry brooding house waterlines

An in vitro experiment was performed to determine if biofilm would develop when polyvinylchloride (PVC) test coupons (material used for poultry waterlines) were exposed to low bacterial content warm water (≤1000 cfu/mL, test water) and also to determine if biofilm development would be influenced by adding a sanitizer. PVC sections 2.54 cm long and internal diameter of 1. 90 cm were used as test coupons to grow biofilm. Two coupons were immersed in 600 mL test water in a beaker. Nine beakers were utilized similarly with a total of 18 coupons. Three beakers (T1) were treated with a chlorine (Cl) based product (targeted to produce 2 to 4 ppm residual) and the other 3 (T2) with hydrogen peroxide a (HP) based product (targeted to produce 25 to 50 ppm residual). Three untreated beakers served as controls (T3). All beakers and coupons were placed into a water bath shaker under warm and moving water conditions mimicking poultry brooding conditions. Coupons and test water were sampled for treatments for aerobic plate count (APC). Trial 1 used test water with zero cfu bacteria/mL initial APC, whereas the Trial 2 test water initial APC was 3 log10 cfu/mL. Test water samples and coupons had no bacterial growth for all treatments on sampling occasions for Trial 1. In Trial 2, T3 (control) and T2 (HP treated) had APC growth in both test water (2.5 to 3.0 log10 cfu/mL) and on coupons (2 to 2.5 log10 cfu/cm2) on sampling d with no difference (P > 0.05) between these treatments. Whereas, T1 (Cl treated) eliminated bacteria (zero cfu/mL) in test water and inhibited biofilm growth on test coupons (≤0.2 log10 cfu/cm2) during sampling d (P < 0.05). This experiment showed that biofilm can develop in minimally contaminated water even in the presence of sanitizers, yet chlorine was more effective than hydrogen peroxide in limiting this development.

МЕТОДИКА ОЦЕНКИ КАЧЕСТВА ВОДЫ С ПОМОЩЬЮ ПОВЕДЕНЧЕСКИХ РЕАКЦИЙ РЫБ

The proposed technique of water quality assessment is intended for monitoring and measuring the behavioral responses of fishes in minimally structured environment, and further evaluating the reactivity of the fish nervous system. Tests were conducted in the period from 11 May to 7 June, 2016 at the sea coast station of the Southern Scientific Center of the Russian Academy of Sciences (Kagalnik village, the Rostov region). As test-objects (bioindicators), there were selected three species of gobies: round goby ( Neogobius melanostomus ), monkey goby ( Neogobius fluviatilis ) and goby Shearman ( Neogobius syrman ). Fish behavior was assessed by response to external stimuli, which is manifested by increased or decreased locomotor activity. Expected and phone activity has been defined. As the test stimuli there were used: a low-frequency sonic boom, a sinusoidal audio signal, a high-frequency sonic boom, an electrical stimulus. Testing water samples were taken from three stations in the water area of the Gulf of Taganrog (estuary of the Don, middle section of the bay and section of the river close to the coastal base). The results showed that the developed method is sensitive to changes of natural water pollutants and can be used in the monitoring system, as a component for coastal stations on the test areas of the Azov Sea in terms of bioindication data matching techniques to identify natural and anthropogenic sources of pollution.

Development of Water Quality Map for Ogbomoso Metropolis

The quality of water is usually strongly considered as criteria for its suitability for a purpose. Important physical, chemical and bacteriological properties form the basis to judge the quality of water. To determine whether a particular water sample is of acceptable quality for drinking, it is necessary to compare its properties with the regulatory limits of certain well known and accepted standards set by organizations like World Health Organization, US Environmental Protection Agency, Nigeria International Standards etc. The focus of this project is to investigate the extent of contaminants in the available water sources and the causative agents in Ogbomoso North and South Metropolis. 100 water samples were collected through an evenly spread sample point positioning system across the study area, to give an averagely accurate analysis of the result. The Physical properties like Temperature, Turbidity, Total Dissolved Solids; Chemical parameters like Heavy metal concentration and Bacteriological parameters like E-Coli and T-Coli coliform count were analysed and the results were compared with regulatory limits. From the results derived, the physical parameters of tested water samples fall within the WHO standard limits. However, water samples in Ogbomoso North and South Local Government Area contain E-Coli and T-Coli concentration that exceeds the WHO standard of 0 MPN/ 100ml. Wards like Ilogbo (Papa Abede) and Ilogbo/ Arada were found to contain high concentration of Iron that exceeds the acceptable 1 mg/l limit due to the presence of a number of dumpsites and light industries. Phosphate concentration in all water samples tested exceeded the WHO and NIS standard of 5 mg/l, which is as a result of uncontrolled septic waste and fertilizer run-off. The concentration of Manganese in all water samples across the study area also exceeded the 0.2 mg/l WHO and NIS standard for potable water as a result of the unchecked Industrial activities and vehicle emission in the area. Other areas with significant pollution cases especially Sulphate concentration that exceeds the WHO regulatory limit of 250 mg/l in water samples include Osupa and Jagun, this can be attributed to the number of the dumping sites present and action of leachates in the areas. The resulting health implication of these findings was discussed. A water quality map was developed to show the varying concentration of water properties across Ogbomoso North and South Local Government Area. The study suggests waste control activities be adopted in the study area and public enlightenment schemes to protect water sources in the area, as the task of reducing the extent of contaminants in water sources in Ogbomoso North and South LGA requires the effort of the residents, government and relative organizations.

Major factors influencing boron adsorption in sediments—a case study of modern sediments in Qinghai Lake

Because the boron (B) concentration in water has an apparent positive correlation with salinity, the B content adsorbed in sediments is often regarded as an important indicator to reconstruct the water salinity in a sedimentary environment. The premise of the quantitative reconstruction of paleosalinity is that the B uptake in sediments is proportional to the B concentration in water; however, the study showed that there is no direct relationship. The B absorption in sediments can be affected by both the content of the clay minerals and the total organic carbon content. The data from testing modern sediments and water samples in the Qinghai Lake show that a higher content in clay minerals is beneficial for B adsorption. Furthermore, the organic carbon from halophiles has a strong effect on the enrichment of B. Therefore, the organic carbon content in sediments should be considered when the paleosalinity of water is reconstructed using its B content. It is also thought that the Adams and Couch formulas are not suitable for reconstructing the salinity of water with a high organic carbon content in sediments because they consider only the effect of clay minerals on the adsorbed B without the contribution of organic carbon.

Potential health risk assessment due to the presence of toxic metals in drinking water from individual wells in the village of Dubravica in the Branicevo district

In order to verify the content of macro- and microelements in drinking water in the village of Dubravica in the Branicevo district, which has no centralized water supply system, an analysis of the water sampled from two individual wells was conducted using the indirect method recommended by Rajkovic and associates. Tests on the RDA and AAS showed that: Al, Fe, Cr, Pb and U were in concentrations higher than the values allowed by Regulations on the hygienic quality of drinking water. To determine the risk of the presence of toxic metals in the elevated concentrations, the assessment of short-term and long-term potential carcinogenic risks was conducted. Based on the results obtained in the tested water samples, it is noticed that the value of the coefficient of risk (CR) was less than 1 for all potentially toxic metals that were determined in drinking water, which implies that there is no short-term carcinogenic potential risk to human health. Based on the results of the long-term potential risk for the occurrence and development of cancer, the risk of getting cancer of Cr was identified in the inhabitants of the village that used potable water of the first sample. In case of Pb, a risk of developing cancer, concerning the first sample of drinking water, may occur in 44 out of 1000 people and regarding the second sample, in 183 out of 1000 people. Based on the calculated estimates of the long-term health risk related to the presence of U in drinking water, it can be seen that there is a health risk related to the use of both water samples. On the basis of the calculated estimates of the long-term health risk related to the presence of uranium in drinking water, it can be noticed that the use of both water samples may lead to the potential risk of developing cancer: in 24.5 inhabitants regarding the first water sample and in 10.3 out of 1000 inhabitants in the case of the second water sample.

Bacteriological analysis of water samples and the impact of seasonal variation on microbial load

Water plays a significant role in the very existence of life in this universe. Globally, water related diseases present a major concern, to a large set of population. It thus becomes vital to check the quality of water that is being used either in domestic set up or for industrial purpose. In the present study, microbiological analysis of water sample collected from different locations such as River, Lake, Well and direct Rain water in and around Manipal, Karnataka were studied. The impact of seasonal variation on microbial load of these samples was also studied. The experimental design was carried out to estimate the number of microorganisms present and to characterise what type of organisms they are and the influence of varying seasons such as wet (monsoon) season and dry (summer) season on microbial load. Number of colonies was determined by total plate count method and growth characters and pattern were observed and noted down. Examination of motility of bacteria, Gram’s staining and different biochemical tests (IMViC) for bacteria were performed for different bacterial cultures and also the fungal staining was performed for the different fungal isolates obtained from the water samples. To check the quality of water for domestic and industrial use and to check for presence of faecal matter in water samples, the test for coliform bacteria through presumptive, confirmed and complete tests were performed. The results showed that all the water samples were safe for use as coliform organisms were not detected in the tested water samples, both in wet as well as well as dry season. The impact of seasonal variation that is the effect of dry and wet season on microbial load was also noted down. The various parameters that were examined to check for microbial load in varying seasons included difference in the number of colonies of microorganisms, their growth pattern and growth characters. From the tests conducted it was found that diverse and greater microbial load was observed in wet season compared to dry season.

FACTORS AFFECTING GROUNDWATER QUALITY IN THE CONTEXT OF THE EXPLOITATION OF SMALL DRINKING WATER INTAKES

Abstract In this work, attention has been paid to the problem of quality of groundwater, which is the main source of supply of drinking water for rural inhabitants. In particular, the important factors for the groundwater quality in rural areas have been presented. This paper also shows the impact of the quality and quantity of available water resources on the exploitation of chosen small water intakes. Results of research on the quality parameters of groundwater, obtained in 2012÷2016 for selected rural intakes in north-western Poland, were presented. There was an increase in the content of iron and manganese compounds, ammonium ions, as well as the presence of bacteriological contaminants in test water samples. For these reasons, problems with providing the receivers with water of appropriate quality parameters have been reported in described rural intakes. The paper is an attempt to show the relationship between the type and magnitude of changes in the groundwater quality and the efficiency of the water treatment. In addition, pro-quality activities undertaken by local water companies were emphasized.

Essential Skills in Postgraduate Medical Curriculum of Community Medicine

Introduction: Community-based education has been considered a suitable approach for health promotion and for requisite skill development regarding primary health care. In the current perspective, public health training and research, being two important aspects require immediate attention. Objective: To assess the skills of Postgraduate Students in the Department of Community Medicine in four Medical Colleges of Delhi. Materials and Methods: It was a cross-sectional study conducted among 70 Postgraduate Medical Students of 4 Medical Colleges in Delhi. The data were collected through a self administered, pretested questionnaire containing items assessing socio-demographic profile and skills essential for Postgraduate Students of Community Medicine. Results: There were 58.6% male and 29% female students. A large proportion of participants were having age range between 25-29 years. Ability 'to resolve conflict among the nurse at Primary Health Centre (PHC)', 'generate community participation', 'making thick and thin smear in case of fever', 'making a chart showing month-wise distribution of CuT', and 'calculating Chi-square of data', were found to significantly higher in 2nd and 3rd year PG students than first year PG students (p&lt;0.01). Only 27.1% of students felt that they could test water sample for microbiological aspects while only 47.1% said that they could examine an industrial worker for pre-placement examination. Conclusions: PG students assessed themselves to possess necessary skills on communication, counselling and health education. However, many students lacked skills pertaining to occupational health and epidemiology.

Internet of things enabled real time water quality monitoring system

AbstractSmart solutions for water quality monitoring are gaining importance with advancement in communication technology. This paper presents a detailed overview of recent works carried out in the field of smart water quality monitoring. Also, a power efficient, simpler solution for in-pipe water quality monitoring based on Internet of Things technology is presented. The model developed is used for testing water samples and the data uploaded over the Internet are analyzed. The system also provides an alert to a remote user, when there is a deviation of water quality parameters from the pre-defined set of standard values.

Identification and quantification of pesticide residues in water samples of Dhamrai Upazila, Bangladesh

Being agricultural country, different types of pesticides are widely used in Bangladesh to prevent the crop losses due to pest attack which are ultimately drain to the water bodies. The present study was conducted to identify and quantify the organochlorine (DDT, DDE and DDD), organophosphorus (malathion, diazinon and chloropyrifos) and carbamate (carbaryl) residues in water samples of different sources from Dhamrai upazila of Bangladesh using high performance liquid chromatography (HPLC) equipped with ultra violate (UV) detector. Thirty water samples from fish pond, cultivated land and tube-well were collected in winter season to analyze the pesticide residues. Among the organophosphorus pesticides, malathion was present in seven water samples ranging from 42.58 to 922.8 μg/L, whereas diazinon was detected in water sample-8 (WS-8) and the concentration was 31.5 μg/L. None of the tested water samples was found to be contaminated with chlorpyrifos, carbaryl or DDT and its metabolites (DDE and DDD). Except for a tube-well water sample, concentrations of the detected residues are above the acceptable limit for human body as assigned by different organizations. To avoid the possible health hazards, the indiscriminate application of pesticides should be restricted and various substitute products like bio-pesticide should be introduced in a broad scale as soon as possible.

Evaluation of the properties of potassium ferrate used for water purification by luminescence bioassay

Characteristics of four natural water samples from urban and rural areas and the efficiency of a new purifying agent, potassium ferrate K2FeO4, were studied by bacterial luminescence bioassay for 30 minutes. It was revealed that two samples of water from the urban areas are toxic, while the other two samples (one from urban and one from rural environment) are nontoxic. Numerous data obtained on the increase in toxicity index with time allow reasonable conclusions to be made about the chemical nature of substances present in the test water samples. Toxic natural water samples were likely to contain heavy metals and were well purified using potassium ferrate, including via their adsorption. In nontoxic natural water samples, toxic complexes with organic compounds present in water could form at the addition of potassium ferrate. The obtained data call for further studying the properties of potassium ferrate complexes with organic compounds. Bacterial luminescence bioassay is a promising method for the rapid assessment of properties of various water sources (their integral toxicity and presumable chemical composition) and new reagents for their purification (effective concentrations, bactericidal properties, and mechanisms of interacting with heavy metals and organic substances in water).

Investigating Arsenic Contents in Surface and Drinking Water by Voltammetry and the Method of Standard Additions

Testing water samples for arsenic contamination has become an important water quality issue worldwide. Arsenic usually occurs in very small concentrations, and a sensitive analytical method is needed. We present here a 1-day laboratory module developed to introduce Earth Sciences and/or Chemistry student undergraduates to key aspects of this topical issue. In this practical session, students were first introduced to the worldwide problems of arsenic contamination in groundwaters as a motivation of the experimental work. The latter consisted of quantification of arsenic levels in surface and drinking water at trace levels (nM, ppb) using the electroanalytical technique of anodic stripping voltammetry and the method of standard addition. Results were discussed with respect to water quality guidelines and geology. The complexity of data interpretation in this exercise can be tailored to a range of abilities and subject areas suited to the students and the course.

Preparation and Testing of Impedance-based Fluidic Biochips with RTgill-W1 Cells for Rapid Evaluation of Drinking Water Samples for Toxicity

This manuscript describes how to prepare fluidic biochips with Rainbow trout gill epithelial (RTgill-W1) cells for use in a field portable water toxicity sensor. A monolayer of RTgill-W1 cells forms on the sensing electrodes enclosed within the biochips. The biochips are then used for testing in a field portable electric cell-substrate impedance sensing (ECIS) device designed for rapid toxicity testing of drinking water. The manuscript further describes how to run a toxicity test using the prepared biochips. A control water sample and the test water sample are mixed with pre-measured powdered media and injected into separate channels of the biochip. Impedance readings from the sensing electrodes in each of the biochip channels are measured and compared by an automated statistical software program. The screen on the ECIS instrument will indicate either "Contamination Detected" or "No Contamination Detected" within an hour of sample injection. Advantages are ease of use and rapid response to a broad spectrum of inorganic and organic chemicals at concentrations that are relevant to human health concerns, as well as the long-term stability of stored biochips in a ready state for testing. Limitations are the requirement for cold storage of the biochips and limited sensitivity to cholinesterase-inhibiting pesticides. Applications for this toxicity detector are for rapid field-portable testing of drinking water supplies by Army Preventative Medicine personnel or for use at municipal water treatment facilities.