Efficiency Analysis of Coagulant and Energy Consumption of Surabaya Water Treatment Plant using Data Envelopment Analysis Method

The high demand for clean water in Surabaya has driven the optimisation of the water treatment process at three water treatment plants (WTPs). The primary challenge is determining the optimal dosage for coagulation and flocculation, which play a crucial role. DEA was used to assess the optimum coagulant dosage. The DEA calculates the coagulant dosage efficiency score and energy consumption in every WTP unit, with a threshold score of 1. The DEAP 2.1 software performs the assessment simulation. When the WTP score is 1, it is considered efficient in saving coagulants, and an energy A score below 1 indicates inefficiency in conserving those resources. The inputs are energy requirements and coagulant doses between 2018 and 2022. The outputs are water quality parameters such as turbidity, total dissolved solids (TDS), and colour. The highest efficiency performance was obtained by WTP 2 (46%), followed by WTP 3 (43%) and WTP 1 (29%). Overall, the recommendations for energy efficiency and coagulant dosage efficiency vary. The energy efficiency improvement recommendations are pump monitoring, maintenance of the electromotor, and supervision of the main assets. On the other hand, maintaining optimal coagulant requirements, selecting the right coagulant, and administering flocculants effectively are key.