Development of Improved Liming Process based on Automated pH Monitoring and Control System

The control of pH of a process plays an important role in many chemical or biological reactions. The monitoring and control of pH of processes like wastewater treatment, manufacturing food and leather making facilitate to reduce pollution and improve the quality of the final product. The focus of this study is to optimize the usage of lime and recycling of spent liquor through continuous monitoring system of pH to achieve near zero residue from liming operation. But the challenges are nonlinear behaviour of the system and frequent fouling of pH sensors. The system developed monitors the pH values and controls the cycling time and the addition of lime as per the user set profile. The real time data of pH values in the process is logged on to the PC for further analysis. The efficacy of the system developed was validated at lab level and can be easily scaled up for implementation in industries. The results showed that the effluent from leather making can be minimized by adopting automated pH monitoring and control systems.