Sustainable and Safe Treatment of Wastewater of Paint Industry Using Azadarachta indica Leaf Extract Combined with Silver Nitrate Solution

Abstract

This study was conducted to assess the effectiveness of a combined green and synthetic solution for the sustainable treatment of wastewater from the paint industry. Effluent was treated with a natural plant extract (Azadarachta indica) and a silver nitrate solution (AgNO3). Three composite samples of wastewater were collected from the paint industry, transferred to the laboratory for analysis, and three case studies were applied for treatment. The parameters of the treated water were compared with the Punjab Environmental Quality Standards (PEQS). Case 1 was a control treatment in which discharged industrial effluent was collected and analyzed for various pollutants (pH, COD, TDS, TSS, and BOD). All the target parameters were higher than the limits in the PEQS. In Case 2, the wastewater was treated by reaction with an A. indica solution for a 4 to 72 h retention time. Some pollutants were remediated as a result of the reaction, while the majority of pollutants required a longer retention time and a higher concentration of A. indica extract, making this case applicable for the treatment of wastewater. In Case 3, the discharged industrial effluent was reacted with A. indica solution combined with AgNO3 solution for wastewater treatment with a 4 to 72 h retention time; after reaction, all the pollutants were remediated at high pH of 12 at a retention time of 24 h. However, a longer retention time and a better solution are required for the treatment of priority pollutants. However, Case 3 treated more pollutants, so was far superior to Cases 1 and 2. As a result, this instance is suitable for the treatment of wastewater from the paint industry.