A Study on Polymer-induced Flocculation in Industrial Wastewater Treatment Via a High-throughput Method

Abstract

The main purpose of specialized industrial wastewater treatment facilities is to treat incoming wastewater loads from various industries which do not have the capability of treating their wastewater on site. Accordingly, specialized industrial wastewater treatment facilities face a challenge in quickly identifying optimal treatment options for the varying incoming wastewater loads they receive. With the new discharge limits set by the federal Wastewater System Effluent Regulations (WSER) and a compliance deadline by 2020, it became crucial for such facilities to optimize their processes and ensure having a method to determine optimal treatment options and conditions to meet the new discharge limits. One such limit is the Chemical Oxygen Demand (COD), which is representative of the amount of organic matter present in a solution. Polymer flocculation is a common mechanism used for solid-­liquid separation in industrial wastewater treatment. While many previous research studies have been previously conducted on polymer flocculation and industrial wastewater treatment, there seems to be a lack in studies that focus on running experiments in a rapid high-­ throughput manner and using samples that vary in composition and come from different generators/sources. In this work, a high-­throughput method was implemented to investigate several aspects in the polymer flocculation area on various wastewater samples obtained from a specialized industrial wastewater treatment facility. Using this method, the optimum polymer flocculant type, dosage and concentration were successfully identified for several wastewater samples. In addition to that, scale-­up experiments were done in the v facility on various wastewater tanks to compare the performance of undiluted and diluted polymer flocculant. Diluted polymer flocculant was proven to successfully treat wastewater tanks to a level safe enough for discharge and just as good as undiluted polymer flocculant while using less “neat” polymer flocculant volumes. Moreover, possible cost savings and a better treated water quality were also achieved by implementing multi-­staged polymer flocculation concept for industrial wastewater on a small scale. This work also focused on testing the FBRM as an in-­line method for particle size distribution measurements in industrial wastewater. However, even after an optimization attempt, it did not work well on the samples tested. Another in-­line method that was also tested was UV spectroscopy. This method was proven to successfully work as a method to determine optimum polymer flocculant dose and could be a promising in-­line tool. Finally, bentonite was used as a flocculation aid along with polymer flocculants and design of experiments (DOE) methods were implemented to almost successfully reduce the COD, which as mentioned is an important water quality parameter, in automotive industrial wastewater samples with initial average COD of 77,000 ppm to the safe discharge limit (i.e. 600 ppm)