Removal of Pollutants in the Wastewater Treatment of Industrial Park of Semnan City with the Help of Chemical and Natural Coagulants

Due to the expansion of industries and the increase in the volume of industrial wastewater, as well as the reduction of natural water resources and the water shortage crisis in human societies, adopting appropriate methods to remove pollutants and treat wastewater has become necessary. In this way, the high volume of industrial effluents can be optimized by recycling the water used to bring the pollutants to the standard level for various purposes such as washing factory equipment, watering green spaces and trees, etc. Among different methods such as membrane filtration, reverse osmosis, etc., the use of absorbents to remove pollutants can be effective in achieving the goal with optimal efficiency and low cost. Coagulants, both chemical and natural, are used to remove the blockage of the absorbent and reduce the need for their regeneration or replacement. This research aims to compare the performance of several different coagulants from different groups, along with zeolite adsorbent, to treat the central sewage effluent of Semnan Industrial Park. The role of this process in reducing COD, TSS and turbidity is also investigated. The obtained results show the optimal performance of polyammonium chloride with a reduction of 60% for COD, 85% for TSS and 85% for turbidity. Similarly, Moringa, as a natural absorbent, exhibits high removal efficiency, with a reduction of 70% for COD, 75% for TSS, and 80% for turbidity. The use of two chemical and natural methods will be very effective in reducing pollutants to the allowed amount depending on the type of wastewater.