V. Meseguer

Sewage Treatment with a Hybrid Constructed Soil Filter

Abstract The overall aim of this research was to apply a hybrid constructed soil filter for sewage treatment. A hybrid constructed soil filter is an ecological process used for decentralized sewage treatment in villages, small towns or scattered residential areas. Sewage is firstly treated by conventional physicochemical or biological treatment and then allowed to infiltrate through aerated unsaturated zone wherein it gets purified through processes such as filtration, adsorption, chemical reaction and biodegradation. This system has demonstrated a consistent capacity to remove organic matter and nitrogen. Experimental results have shown that under hydraulic load rates of 0.22 m3/m2 · h and organic load rates ranging from 47 to 156 g COD/m2 · h, mean removal efficiencies of 89% for COD, 99% for BOD5, 86% for suspended solids and 52% for total nitrogen can be achieved using an hybrid constructed soil filter. Compared to the conventional activated sludge process, this technology has many advantages, such as simple construction, low operation and maintenance costs, as well as a simple operation.