Comparative Filtration of Laundry Wastewater using River Sand & It’s Quality Enhancement through Multimedia Filtration

Abstract

Water is an essential component of our natural environment, often referred to as life. However, human activities have significantly contributed to the contamination of this precious resource. A worthy illustration of water pollution is the wastewater generated from laundry activities. This study aims to assess the quality of laundry wastewater by evaluating various quality parameters and to determine which one sand among two, sourced from the beds of the Turag and Padma Rivers, is more effective for filtration purposes. The reason behind utilizing riverbed sand lies in its composition, which includes silica, mica, and feldspar, all known for their efficacy in wastewater filtration. The study involved installing the more effective riverbed sand into a multimedia filter as a layer to observe enhancements in the removal rates of contaminants. Two separate single-layer sand filters, each using sand from the Turag and Padma riverbeds, demonstrated significant removal capabilities for total solids, total dissolved solids, and total suspended solids. After proper analysis, the results indicated that the filtration process produced quality effluents that met the Environmental Conservation Rules (ECR) 2023 guidelines for industrial effluent discharge into inland water bodies. When subjected to proper filtration through the multimedia filter, which included one layer of better river sand among Turag and Padma in terms of filtration capacity, commercial granular activated carbon, and coarse sand, the average removal rates for colour, turbidity, total solids, total dissolved solids, total suspended solids and chemical oxygen demand were about 95%, 98%, 84%, 84%, 80% and 68% respectively which can be considered as a remarkable example. Additionally, the average dissolved oxygen (DO) increase was 284.3%. These findings underscore the potential of riverbed sand, particularly when integrated into a multimedia filtration system, to significantly enhance the removal of pollutants from laundry wastewater. This study not only provides a viable solution for mitigating water pollution but also contributes to the sustainability of the environment.