Iranian Journal of

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Backgrounds and Objectives: Determination of arsenic(As) in drinking water has received increasing interest due to its detrimental effects on health. The aim of this research is to investigate effect of coating coral limestone using aluminum sulfate as an adsorbent on the arsenic(V) removal efficiency from aqueous solution. Materials and Methods: In this laboratory scale study, we prepared coral lime granules using mesh 30 during several stages. Then, we investigated the arsenate removal efficiency under different conditions and changing main factors including pH, contact time and amount of no coated and aluminum sulfate-coated adsorbent. Moreover, we fitted our results with Langmuir and Freundlich models and kinetic data with pseudo- first order, pseudo- second order and modified pseudo- first order models. Results: We found that increasing pH from 3 to 10 at arsenate concentration of 500 ppb and 5 g/l adsorbent and 120 min contact time, removal efficiency for no coated and coated adsorbent was reduced from 100 to 86.2% and from 100 to 92.2% respectively. Increasing concentration of both adsorbents from 1 to 5 g/l at contact time 120 min increased the removal efficiency from 76 to 99.2% and from 66.3 to 91.1% respectively. Arsenate removal efficiency was directly proportional with the amount of adsorbent and contact time and reversely proportional with the initial concentration of arsenate and pH. The removal efficiency of the coated adsorbent was more than uncoated adsorbent. Langmuir was the best sorption isotherm model for arsenate in these two processes and absorption kinetic was well described with second order models. Conclusion: Excellent removal efficiency, cost-effectiveness process, and lack of environmentally harmful substances make application of the Persian Gulf offshore corals a reasonable adsorbent to remove environmental contaminants such as arsenate.

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Background and Objective: Collection and disposal of waste has an important role in public health. Isolation and separation procedures at the origin is considered as one of the most important and least costly methods of isolation and separation of waste. This study was aimed to culture and educate those involved in recycling and waste reduction in the Kalaeh City using two educational methods. .

Materials and Methods:  This semi-experimental study was conducted in Kalaleh City. In the social and cultural context,   Kalaleh was divided into six regions. Using cluster sampling, regions were selected randomly. In each area, 120 samples were used. The first group was face-to-face trained and the second group received training through the training package. Waste collection period was 60 days. After this time, the questionnaires were again filled up  and the impact of teaching methods were investigated.

Results: Face-to-face training resulted in increasing waste separation from 70.8 (before training) to 95%. Whereas, this figure in the group receiving training package increased from 57.5 (before training) to 86.7%. Waste recycling rate was between 0.6 to 1 Kg per person per week. These wastes included paper, glass, plastic, and metal containers. On average, the waste recycled in face-to-face training group and training package group was  91 and 83 Kg per week.

Conclusion: Knowledge, attitude and cooperation in waste separation increased after training in both groups. However, in the face-to-face training group, the knowledge and participation in waste separation was more compared with training package group. Continuous training and organizing waste separators could be helpful to re-use waste. It causes less pollution of the environment, reduce the transmission of diseases associated with non-systematic disposal of solid waste, reduce costs and increase awareness about the problems and issues of solid waste, and reduce the solid waste volume.