Proceedings of the 8th International conference on Research in Engineering, Science and Technology
Investigating Pretreatment of Seawater using Precipitation agents to reduce Scale formation in distillers
Khedidja Dahmani, Mohamed Belloul and Djamal Eddine Kherroub
The aim of this study is to treat the scale formation in multi stage flash distillers. The scale results from the precipitation of insoluble species notably calcium sulfate as well as calcium carbonate and hydroxide magnesium. The proposed solution involves a pretreatment of seawater before it is introduced into distillers. The pretreatment is based on the removal of the calcium and magnesium cations from seawater, using precipitating agents as: soda ash, potassium hydroxide, and mixture of soda ash with potassium hydroxide at different temperature of 25, 35, 50, and 100 °C. Pretreatment achieved by a mixture of potassium hydroxide and soda ash of seawater gave the best results. In addition, the results showed that by mixing soda ash (10g/L) and potassium hydroxide (3g/L) at temperature of 100 °C favor the precipitation of calcium and magnesium ions. The calcium and magnesium concentrations in seawater were completely reduced.
Keywords: desalination, scale, temperature, soda ash, potassium hydroxide.