A 3-stage treatment system for domestic wastewater: Part 1. Development

Abstract

This study presents the development of a micro-scaled 3-staged wastewater treatment system applicable to small volume domestic effluents. The primary components of the system include 1) Spiral-Framed Human Hair-Based Filter, 2) Plastic Medium Mixed Flow Biotower, and 3) Pistia Stratiotes- Based Free Surface Water Wetland System. The first stage Spiral-Framed Human Hair-Based Filter consists of an oil and grease removal apparatus filled with human hair blocks and operated in a spiral plane aimed at removing emulsified oils from wastewater. The process is followed by a second stage Plastic Medium Mixed Flow Biotower filled with perforated cylindrical plastic tubes in horizontal and vertical arrangements to provide alternate vertical and cross flows for removal of suspended solids, ammoniacal-nitrogen, and biochemical oxygen demand. The effluent would then be channelled to the free surface water wetland system (third stage) filled with Pistia Stratiotes (water lettuce) for removal of nutrients such as nitrogen, phosphorus, and potassium from wastewater. From this study, it was found that Human Hair-Based Filter could remove 73.54% emulsified oils from wastewater, while the combined removal efficiencies of Plastic Medium Mixed Flow Biotower and Free Surface Water wetland system operated in series recorded 59.2% biochemical oxygen demand, 87.9% ammoniacal-nitrogen, 90.6% nitrogen, 54.9% phosphorus, 68.5% potassium, and 59.0% turbidity.