الفهرس | Only 14 pages are availabe for public view |
Abstract In hot climatic countries which used oxidation ponds. the temperature is very high. and this lead to loss much amount of pond water by evaporation. The amount of evaporation in some cases may exceeds the influent to the pond. So. the concentration of salts increase to a higher values. The increase of salts concentration effect the growth of algae and bacteria in the pond. Algae produce oxygen. which consumed by bacteria. and this bacteria oxidize the organic matter to a stable matter. and thereby make it non-putricible - and so effect on the efficiency of oxidation ponds. This discusses the effect of salts concentration on oxidation ponds efficiency. Sodium chloride and magnesium sulphate are used with different concentrations. The effluent BOO. algae suspended solids. and pH were determined. The results of this study showed that: 1. The maximum efficiency was obtained when the oxidation and pond works naturally under water temperature ranges fr orn 25 to 35°C during summer period. And the maximum efficiency was 84 %. and this was acceptable. 2. In hod cl imatic countries where the temperature was very high. and the amount of evaporation was very much. and may be exceeded the influent flow. Salts concentration increased as a result of high temperature and effected the growth of algae and bacteria in the medium. 3. For sodium chloride concentrations less than or equal to 3250 mg/L the BOO removal ratio was range from 84% to 68%. For sodium chloride concentrations above 4250 mg/L the BOO removal ratio was about 20 80 when sodium chloride concentrations exceeds 3250 mg/L. the pond must be washout or add fresh water to dilute it. But this is not practical and not economic. 80 it is recommended that use other method for treatment when sodium chloride concentration exceeds 3250 mg/L. because oxidation ponds are not suitable in this case. But if inexpensive land and a source of fresh water are available to dilute the oxidation ponds. the oxidation ponds will be suitable to treat sewage in that case. It. In case of sewage containing high concentration of magnesium sulphate. the’ efficiency of oxidation ponds are not suitable for that. And it was recommended to use another method for sewage treatment. 5. The previous salts can be used by suitable doses to I imit the number of algae and bacteria in the effluent from oxidation ponds and to obtain the special effluent. |