| Abstract |
| In this study, we developed a program called CTL_BSK that could compute injection with to control corrosive waters using Langelier index(LI). The program composed of three modules, and each module incorporated parameters such as temperature, calcium hardness, alkalinity, pH, and conductivity or TDS. The LI of the raw water sampled for three days in G purification works was ranged from -1.62 to -1.06 that means the water is corrosive. To change corrosive waters to noncorrosive waters, lime injection with carbon dioxide was found using a developed model. When the target pH was step up to be 8.5 and calcium hardness was increased to 50, 60, 80, 100 mg/L as , through simulation we obtained the lime injection of 0.026, 0.044, 0.081, 0.118 L/min with carbon dioxide of 0.107, 0.227, 0.468, 0.709, respectively. As a result of adding lime with carbon dioxide, the LI was estimated to be -0.04, 0.12, 0.38, and 0.58 for pH 8.5. Judging from the LI, the water changes from corrosive to noncorrosive at critical concentration of calcium harness between 50 and 60 mg/L for pH 8.5, while the critical condition locates between 60 and 80 mg/L for pH 8.0. Optimum water quality condition was estimated to be calcium hardness 68 mg/L, and alkalinity 64 mg/L for pH 8.0, while calcium hardness 51 mg/L, and alkalinity 47 mg/L for pH 8.5. For various water conditions, the model provides appropriate amount or rate of dosage of corrosion inhibitor. In conclusion, the program could serve as a useful tool for the control of corrosive water. |
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| Key Words |
| program, lime injection, carbon dioxide, dosage, corrosive |
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