Archives of Hygiene Sciences
Volume:1 Issue: 1, Summer 2012

Aims of the Study: The aim of this study was to determine the amount of lignin degradation and biodegradation of organic matter and change of biomass under compost and vermicomposting of sewage sludge. Sawdust was added to sewage sludge at 1:3 weight bases to Carbon to Nitrogen ratio of 25:1 for composting or vermicomposting. Lignin and volatile solids were determined at different periods, of 0, 10, 30, 40 and 60 days of composting or vermicomposting period to determine the biodegradation of lignocellulose to lignin. Results were expressed as mean of two replicates and the comparisons among means were made using the least significant difference test calculated (p <0.05). After 60 days of experiment period, the initial lignin increased from 3.46% to 4.48% for compost and 3.46% to 5.27% for vermicompost. Biodegradation of lignocellulose was very slow in compost and vermicompost processes. Vermicomposting is a much faster process than compost to convert lignocellulose to lignin (p <0.05). The organic matter losses in sewage sludge composting and vermicomposting are due to the degradation of the lignin fractions. By increasing compost age, the amount of volatile solids will decrease.

Aims of the Study: This study was aimed to investigate the adsorption mechanism of the arsenic removal from water by using carbon nanotubes in continuous adsorption column. Independent variables including carbon nanotubes dosage, contact time and breakthrough point were carried out to determine the influence of these parameters on the adsorption capacity of the arsenic from water. Adsorption capacities of single wall and multiwall carbon nanotubes were about 148 mg/g and 95 mg/g respectively. The experimental data were analyzed using Langmuir and Freundlich isotherm models and equilibrium data indicate the best fit obtained with Langmuir isotherm model. Carbon nanotubes can be considered as a promising adsorbent for the removal of arsenic from large volume of aqueous solutions.

Aims of the Study: The objective of this study was to appraise wastewater management approaches in rural areas of Iran, restrictions, effects on environment and also definition of suitable management approaches in wastewater for future. This descriptive study was performed in 2010 in rural areas of Iran. A questionnaire was prepared with subjects such as available management approaches on wastewater, suggested approaches on collecting wastewater and its final disposal and was sent to rural area’s wastewater companies in each province. Study results of 4588 rural areas of Iran (with above 200 families) were collected. Results were analyzed using mean and percentage. The current available management systems were mainly based on absorption wells. The main problem in this system was high ground water levels, and low permeability of soil. The most important current problem of the absorbing wells was considerable damaging effects on surface and ground water. The current wastewater management in rural areas especially in the field of wastewater collection was improper and undesirable. To overcome the current problem, it is necessary to use collecting methods relative to that of region. Considerable attention is required for the application of reused wastewater in agriculture.

Aims of the Study: The physical, chemical and biological characteristics of Karaj River (near the city of Tehran, Iran), has been studied to evaluate the suitability of its water for domestic uses. Samples of water were collected from various localities before, in and after Karaj Dam Lake and were analyzed based on needs for Water Quality Index (WQI) calculation. In this study, WQI were calculated for the best and the poor condition for quality zoning determination of Karaj water quality. Comparison of water quality index in different sampling stations of Karaj River in different years showed that the water quality of this river was better in 2008 compared with years 2007 and 2009; however ANOVA analysis showed no significant difference between the data in these years (p <0.05). The range of water quality was different from medium to good (WQI=50-100), so this water can be used for domestic uses after suitable treatment.

Aims of the Study: This study was carried out to determine the effective factors in environmental health status of grocery stores in the city of Qom (located in the center of Iran). In this cross-sectional study, 283 grocery stores from 3 different regions were selected randomly using stratified sampling. Data were gathered through observation, interview, and questionnaire. The questionnaire consisted of two sections: section 1 dealt with some shop managers’ features including the age, educational level, job satisfaction, passing “food and occupational hygiene training courses”, store ownership, duration of employment, and features of stores including their location (Region) and environmental health condition. And section 2 dealt with the important aspects of regulations of Article 13. The data analyzed using statistical procedures such as Spearman Rank Correlation and Multivariate Regression Analysis. P-values less than 0.05 were considered as statistically significant. Among the investigated factors, the manager’s educational level had a greater impact on the environmental health conditions of grocery stores. The ownership status of grocery stores, Job satisfaction and passing “food and occupational hygiene training courses” were next in the ranking, respectively (p <0.001 for all measures, except for shop ownership, for which p-value was <0.02). Planning and implementation of effective operational and strategic programs addressing the above mentioned issues seems to be necessary. Such programs will improve the health status of the stores over time.