International Journal of Environmental Science and Toxicology Research

152-159

Authors: Abooalfazl Azhdarpoor*1, Payam Mohammadi2, Mansoureh Dehghani1

Phosphorous is the main and key nutrient in freshwater systems which is stimulative to algae, aquatic plants and photosynthetic microorganisms’ growth and should be removed to prevent eutrophication phenomenon. In this study efficiency of removal of the COD (Chemical Oxygen Demand) and the TP (Total phosphate) was investigated using a new anaerobic-aerobic/anoxic modified SBR reactor. An anaerobic-aerobic/anoxic modified SBR reactor was used in 4 different operating phases in time range of 3 to 8 hours in order to reach the best COD and TP removal conditions. The input phosphate concentration and input COD were varied from 4 mg/L to 60 mg/L and from 250 mg/L to 1500 mg/L respectively. The phases 3 and 4 were chosen as the best phases with 91.9% and 84.4% in phase 3 for COD and TP removal efficiencies respectively and also 92.7% and 86.9% for COD and TP removal efficiencies in phase 4. The retention time of phase 4 was included alternatively 225 minutes aeration, 165 minutes mixing and 90 minutes sedimentation. This new reactor has several advantages including high efficiency in removal of organic materials and phosphate, continuity in input flow, the low space and volume occupation. Keywords: Modified SBR reactor, phosphate, Anaerobic, Aerobic.

168-179

Authors: M.H. Amara1 and S.A.Saad2*

This study was carried out in year 2012 to identify the seasonal variation of water quality of Hafirs in North Kordofan State. The study covered four Hafirs, in Shaken Locality (Abu Haraz administrative unit) of 2500 M3 designing capacity and all used as traditional Hafirs without any treatment facilities: Almamsouca village Hafir, Alayaira village Hafir, Algalabai1 village Hafir and Algalabai2 village Hafir. Qualitative characteristics of Hafirs` water were measured in four periods: March, June, September and December, using onsite membrane filtration technique for biological analysis (E-coli and total coliform) and standard laboratory techniques for chemical and physical tests. Also data were collected from the nearest central healthcare facility in the study area to investigate the predominance of water related diseases. Biological quality of all studied hafirs was found to be very poor with very high levels of E-coli and Fecal coliform counts in most seasons with peaks in June and minimum in December and this can be simply correlated to intensive run-off from faecally polluted dry soils to Hafirs positions. Investigation of water related diseases in nearby healthcare facility for last three years shows a very high cases of all water related infections with noticeable incidents of deaths and increasing numbers of bilharzia cases were recorded suggesting a direct reflection of poor biological water quality. Little seasonal variation in all physico-chemical properties of water samples can be noticed but most values comply with the standards of the World Health Organization and Sudanese Meteorology Organization except iron in Alayara and Algalabia Hafirs and turbidity in all hafirs throughout the seasons with peaks in rainy time (June - September). It is recommended that all hafirs must be fitted with slow sand filters and chlorination tanks and surrounding protection fences to improve bacterial and physico-chemical properties of water. Householders should be made more aware on hazards arises from using polluted water and trained to use traditional methods to enhance their drinking water quality. Keywords: Hafirs; North Kordofan; Water quality; Membrane Filtration.