A comparative analysis of defatted pumpkin seed extract and conventional coagulants for sustainable turbidity reduction in water and wastewater treatment

Utilizing novel coagulants as a pretreatment is essential before purification processes like RO membranes, as it helps reduce turbidity from clogging particles. There is an increasing demand for effective plant-based coagulants, and defatted pumpkin seed extract offers a cost-effective alternative to traditional synthetic coagulants. Coagulation experiments were conducted to assess the effectiveness of defatted pumpkin seed extract and identify optimal treatment conditions. Results from synthetic turbid water samples indicated optimal performance at a dosage of 5.5 v/v%, pH 7.38, and a slow mixing time of 10 min, achieving an impressive turbidity removal efficiency of 96.87 %. Conversely, the highest turbidity removal efficiency for industrial wastewater was observed at a dose of 1.5 v/v% and pH 6.05, achieving a removal efficiency of 79.4 %. All statistical estimators indicate that the developed models are statistically validated for simulating the coagulation process. Furthermore, a comparative analysis with Alum, PVA, and chitin was undertaken to assess the effectiveness of pumpkin seeds in reducing turbidity. The outcomes demonstrated that Alum achieved a removal percentage of 98.76 % at 4 v/v%, while combining it with pumpkin seed extract resulted in 98.68 % removal at 3 v/v%. Similarly, PVA showed 94.18 % removal at 1 v/v%, increasing to 97.44 % with pumpkin seeds at 6 v/v%. Additionally, Chitin removed 97.35 % of turbidity at 4 v/v%, with a slight increase to 97.66 % when combined with pumpkin seeds at the same dose. This study characterized the pumpkin seed, highlighting the active content responsible for coagulation. In addition, the estimated treatment cost suggests that pumpkin seed is cost-effective. These findings highlight the effectiveness of defatted pumpkin seed extract as a potential substitute for traditional coagulants in water treatment processes.