Septage treatment in a vertical flow reed bed system

Abstract

The septage disposal and treatment in the Gaza Strip has top priority. About 60% of the urban and rural areas in Gaza Strip are not connected with sewerage system. On-site treatment systems such as septic tanks and cesspools are used to treat human excreta. On a world-wide level, the current technologies for septage and sludge treatment are connected with intensive energy consumption. The application of constructed wetlands for sludge or septage treatment is relatively new. A vertical-flow system, which used for sludge and septage dewatering and treatment in a pilot scale in this work at Rafah–Palestine, investigated the efficiency of utilizing reed bed as low cost technology for the area. The septage collected from Rafah City, was applied to two beds at a regular frequency. One bed is planted with Phragmites australis and one left unplanted. The percolated water (leachate) is measured for each bed. The pollutant removal for each bed has also been assessed. From the 20-month study, the total solids (TS) and hydraulic loading rates were between 110 to 160 Kg/m2. yr and 7 to 17.4 m3/m2. yr respectively. The average evapo-transpiration effectiveness in planted and unplanted beds was 27.7 and 13.2 l/m2. d. In planted bed, the removal percentage of COD and BOS5 were 95.77% and 96.79% where the values for unplanted bed were 91.35% and 91.03% respectively. By high loading, the accumulation of sludge in beds was higher, however; the results presented relatively better performance of planted bed of TS removal. The removals percentage of TKN and TP in planted bed was 98.1 and 99.31% where the removals in unplanted bed …