Sludge drying reed beds for septage treatment: Towards design and operation recommendations

Abstract

With decentralized treatment system development, a new concern emerges: the future of the septage. The aim of this paper is to assess the feasibility of septage treatment by SDRB, and to compare its efficiencies to those of activated sludge treatment in same conditions. The study took place on ten 2m² pilot-scales SDRB. Different designs and operation conditions have been tested on sludge treatment efficiency and will be presented as: (i) the top filtration layer (sand or compost), (ii) the load (from 30 to 50 kgSS/m -2 /y). After one year and half commissioning period, we focus on the results obtained at nominal loads presenting: sludge characteristic, filtration efficiency, percolate quality and sludge deposit behaviour. Although results show better filtration efficiency for activated sludge (98.4%) than for septage (87.5%), the feasibility of septage treatment with drying reed bed has been demonstrated. Sludge accumulation is about 7.9 cm/y, when fed at 50 kgSS/m -2 /y, and dry matter content of the sludge can reach 70% in summer period. The paper will present sludge characteristics, system efficiency, to finish on design and operation condition recommendations for SDRB treating septage.

Recommendation of optimal design and operation parameters for constructed wetland for sludge treatment based on the effect of hydraulic retention time, sludge loading rate and vegetation

“…Moreover, the concentration of TP cannot meet the level A of this regulation even after 14-day HRT with the highest SLR (64 kgTS/m2/yr). This is consistent with previous studies, most of the authentic experience for SLR choice was general 50 and maximum at 60 kgTS/m2/yr [6,10]. The SLR 64 kgTS/m2/yr in this study can be the limit SLR, because a load of 70 kgTS/m2/yr can block oxygen diffusion [11].…”

Treatment of Septic Tank Sludge in a Vertical Flow Constructed Wetland System

“…In this study, the granulometry of the top layer was even larger (2.4-12.5 mm), because gravel was used and not sand. Vincent et al (2011) commented that the substrate layer should guarantee a good filtering of the solids.…”

Developing an Integrated Sustainable Sanitation System for Urban Areas: Gaza Strip Case study

“…The random discharge of this material resulting in degradation of environment and serious public health risks [4,13] such as groundwater pollution and transmission of enteric related diseases [14]. Accumulated human excreta "septage" must be properly treated before disposal [4,15].…”

“…In such system, both dewatering and organic matter decomposition by aerobic biological activity achieved and helped in final formation of organic material in fertile black soil. Several factors influenced vertical flow constructed wetland efficiency such as sludge quality, climate, , loading rates, and feeding frequencies [14].…”