Journal of

Background & Objectives: Nitrate and nitrite compounds pollution of groundwater resources in recent years which recently their mean concentration due to enhancement of different kind of municipal, industrial and agriculture waste water, were increased. The most common source of nitrates entering the water include chemical fertilizers and animal manure in agriculture, septic tank effluent, wastewater, wastewater treatment plants, animal and plant residue analysis on the ground of non-sanitary disposal of solid waste and the use of absorbing wells for sewage disposal.

Materials and methods: This experimental study is applied to the nitrate removal using chitosan in laboratory scale at ambient temperature and the design of the system was Batch. Effects of parameters such as pH, contact time, initial concentration and adsorbent concentration of nitrate on nitrate removal from aqueous solution was studied.

Results: Function of chitosan in synthetic aqueous solution and drinking water according to the slurry system results, the optimum condition was obtained at pH=4, 20 min contact time and increasing the initial concentration of nitrate enhance the adsorption capacity of chitosan. Also optimum dosage of adsorbent was obtained at 0.5 g/l. The data obtained from the experiments of adsorbent isotherm were analyzed using Langmuir and Freundlich isotherm models. The Langmuir equation was found to be the best fitness with the experimental data (R²>0.93).

Conclusion: Although efficiency of Nitrate removal in synthetic aqueous solution was better than drinking water, adsorption process using chitosan as an option for the design and selection nitrate removal should be considered in order to achieve environmental standards.

Background and Objectives: The objective of the study is survey on microbial quality of Maravehtapeh village in during September and October 1391, and its quality compared with national standards and WHO.

Material and Methods: In this cross- sectional study, the water microbial quality in 90 villages have piped city-wide network based on two criteria were assessed total and fecal coliform. 3 samples from each village were sampled during three months. Samples were survey A nine-tube fermentation test s for coliform group. For chlorine residual of diethyl – p- phenylene diamine (DPD) colorimetric method was used.

Results: In this paper, the results of date from 3 round of sampling and testing are presented. The results show that 83.64, 71.43 and 78.89% village with coverage and no coverage of Rural Waste Water Company and all maravehtapeh villages, respective, using safe water in terms of FC and 54.3, 36.37 and 43.34% village with coverage and no coverage of Rural Waste Water Company and all maravehtapeh villages, respective, using safe water in terms of TC.

Conclusion: The results of this study express that the fecal contamination condition in under coverage village is good. But there is a bad condition in villages with no coverage of KRWWC. And the general microbial quality of drinking water in all Maravehtapeh villages of the World Health Organization and country Microbial Index is low.

Backgrounds and Aims: Human health depends more than anything else to clean water and sanitation, thus safety of drinking water is one of the most important community health aspects. The objective of this study was determining microbial quality trend of drinking water in rural area of Kermanshah during 2004-2013.

Material and Methods: This was a descriptive–analytical study. Ten years references laboratory data from Kermanshah Health Center were obtained.  Total coliform, termotolerant coliform and residual chlorine of drinking water samples have been analyzed statistically using SPSS Ver.16.and Excel software.

Results: Base on water quality assessment of Kermanshah, the microbial contamination percent of villages covered by ABFAR decreased from 44% in 2004 to 20% in 2013, whereas in noncovered villages decreased from 70% to 47% during the same time. Contamination rate was lower than the summer time during the winter time. Free chlorine residual testing of drinking water among all studied area improved from 33% to 75% during ten years period.

Conclusion: During last ten years, microbial contamination has been decreased more rapidly in covered villages than non-covered. However, there is still a long distance from the ideal situation. Based on the WHO recommendations on evaluation of microbial safety of drinking water, the average desirable of the bacteriological quality of drinking water in the villages covered by ABFAR in the ten-year period was determined well in winter and bad in summer. These conditions for non-covered villages, was determined moderate in winter and bad in summer. According to chlorination role in water safety, restrict supervision is necessary to provide public health.

Background and Objectives: Population growth and limited access to fresh water and need to use bottled water for drinking, chemical and biological quality of the water exacerbates the need for review. The aim of this study was to evaluate chemical and microbial quality in multi-brand bottled water was consumed in the country.
 
Materials and Methods: A descriptive cross-sectional study carried out in stages, the first brand of bottled water available 6 recognized and sampling was conducted.  The chemical and bacteriological quality of water parameters include cL-, nitrate,Mg+2, Ca+2, hardness, Na+,No2-, pH , TDS, EC, F-, total coliforms and fecal coliforms in the samples were tested. The average value of each property, with standard and were compared with the amounts listed on the label. Data analysis using the software SPSS, descriptive statistics and analysis of variance (p <0.05) were performed.

Results:The results showed that the number of total coliform and fecal coliform bacteria group does not exist in any of the samples and MPN /100cc, respectively. The average concentration of chemical parameters such as pH, TDS, calcium, nitrate and nitrite in all bottled waters, were on the standard ranges. As well as in a number of instances, significant differences between the measured values ​​with the values ​​printed on the label of bottled water there.

Conclusion: According to the results obtained, chemical and biological quality of bottled water is examined in terms of acceptable drinking water standards.

Background &Objective: the advantage of choosing Household water treatment over tap water for drinking is based on the human health assurance of health risks with these devices. The Hazard Analysis Critical Control Points system (HACCP) is a framework that identifies and manages significant hazards at the source to point of use in the process of producing drinking water. This study can be aimed at introducing of HACCP systems as a model to identify the most important potential hazards and control these risks in the flow diagram of RO-based Household Water Treatment in Tehran.
Methods: The possible hazards identified at each step of water production by household water treatment. According to the principle of Seven HACCP, Critical Control Point (CCP) is selected and determined critical limits, monitoring, and corrective action. Sampling water is taken from each critical control point. Physicochemical and microbiological parameters were measured by standard methods.
Results: Results of CCP Risk assessment have confirmed that the parameters of pH, nitrate, total organic carbon, and total coliform and fecal coliform were in the critical limits for defined CCPs. While, the total hardness, fluoride, and HPC were in the critical limit only at the CCP1.
Conclusion: The results showed that the HACCP system can be used to reduce the risks, increase the safety of the output water of the household water treatment. To this end, regular monitoring must be carried out in the specified period by the appropriate operator.

Background and Aim: The presence of various impurities including suspended solids, chemical compounds, bacteria, viruses and other pathogens can reduce the water quality and it has been increased the use of household water treatment plants. Therefore, this study aimed to investigate the effect of household water treatment plants on the microbial and chemical characteristics of drinking water in Ilam city.
Materials & Methods: In this cross - sectional study, 50 household water treatment plants were randomly selected in all the regions of the Ilam city. The parameters of turbidity, pH, free residual chlorine, total dissolved solids (TDS), electrical conductivity (EC), heterotrophic bacteria count (HPC) and fecal and total coliforms were measured in the inlet and outlet water samples of the household water treatment plants.
Findings: The results showed that the removal efficiencies of free residual chlorine, total dissolved solids, electrical conductivity, and turbidity by the household water treatment plants were 100, 70.44, 70.31 and 61.05%, respectively. The removal efficiency for total coliform was 21.61%. The finding also showed that the household water treatment plants had negative effects on the removal of heterotrophic bacteria and fecal coliforms, so that the number of these organisms in the outlet water samples was higher than of inlet.
Conclusion: The results indicated that the household water treatment plants had not acceptable efficiency on the removal of microbial contamination and in many cases even increased the microbial contamination. The water treatment plants also eliminate all the free residual chlorine contents in the water that can be result in the secondary microbial contamination of the treated water.

Nowadays, the increase in population growth rate and followed by anthropogenic activities such as urbanization, industrialization, mining and agriculture practices continuously increase the amount of heavy metals in the environment especially groundwater resources. Therefore, qualitative assessment of groundwater resources is of great importance for maintaining public health and for this reason, this study was conducted to qualitative assessment of groundwater resources of Asadabad Plain using WQI, C_d, HPI, HEI, PoS and MI indices in 2018.
Materials & Methods: In this descriptive cross-sectional study, 120 groundwater samples were collected from 20 stations in the spring and the summer seasons and their temperature, pH and EC values were measured on-site. In the laboratory, the values of physicochemical parameters were determined according to the standard methods. Also, the content of heavy metals was determined using inductively coupled plasma-optical emission spectrometry (ICP-OES). All statistical analyses were performed using SPSS software.
Results: The results showed that the average concentrations of Na, PO₄^-, Cl^-, Ca, Mg and NO₃^- (mg/L) in samples of the spring season were 21.8, 0.230, 0.170, 69.0, 21.1 and 19.3, respectively; and in the summer season were 8.14, 0.190, 0.160, 75.3, 15.6 and 19.8, respectively. Also, the average concentrations of As, Fe, Zn, Pb, Cd, Cr, Cu, Mn and Ni (μg/L) in samples of the spring season were 5.10, 1.61, 0.970, 7.82, 0.230, 1.25, 3.58, 0.360, and 1.30; and in the summer season were 21.4, 1.62, 1.24, 7.63, 0.200, 1.00, 6.73, 0.430, and 1.01, respectively, and except for As in samples of the summer season, the average concentrations of all elements in groundwater samples of both seasons were lower than the maximum permissible concentration (MPC) established by WHO for drinking water. In addition, water quality index (WQI), pollution index (C_d), heavy metal pollution index (HPI), heavy metal evaluation index (HEI), quality index (PoS) and heavy metal index (MI) of samples of the spring season with values of 18.2, -7.53, 9.86, 1.64, 298 and 1.64, respectively, indicate the quality of groundwater were categorized in "excellent and very good", "low pollution", "low pollution", "low pollution", "low pollution" and " slightly affected" classes and in the summer season with values ​​of 17.9, -5.94, 9.86, 3.05, 602, 3.05, respectively, were categorized in "excellent and very good", "low pollution", "low pollution", "low pollution", "high pollution" and "moderately affected" classes.
Conclusion: Although only the average values of As in groundwater samples of the summer season were higher than the MPC, management of the use of agricultural inputs such as pesticides, chemical and organic fertilizers and municipal wastewater for irrigation to maintain the quality of groundwater resources of the study area is recommended.

Monitoring and supervising public water systems correctly by health workers in rural areas can reduce the prevalence of waterborne diseases. Through educational interventions in Shahreza city, we are aiming to improve health workers' knowledge and increase their ability to apply what they have learned about monitoring and supervising rural water supply systems.
Materials and methods:
As a training course and as an intervention, Shahreza's health workers took part in this study.
We used a checklist of water supply systems completed by health workers to collect information about their level of knowledge, their pre-test results, and other relevant information about the current situation. After identifying the lack of knowledge of health workers, the topics the training course should cover were compiled. Following the training course, a post-test was administered to health workers, and checklists completed by the workers before and after the intervention were compared. Using SPSS22 software and paired t-tests and Wilcoxon tests, the data were analyzed, and the effects of the educational intervention measured.
Results: Before and after the educational intervention, the mean scores were 46.2±8.6 and 88.4±8.2, respectively, which indicated a significant difference (P value<0.001). The average risk percentage of all water supply systems decreased from 35.4±5.2 to 19.27±7.6% after the educational intervention, which indicates that the average risk percentage was significantly lower after the intervention than before the intervention (P value<0.001).
Conclusion: This study found that the educational interventions improved both the performance and knowledge of health workers, as well as reducing the risk associated with water supply systems in the rural area.