Performance of an On-Site Wastewater Treatment System Using Reactive Filter Media and a Sequencing Batch Constructed Wetland

Abstract

Many on-site wastewater treatment systems, such as soil treatment systems, are not sustainable in terms of purification efficiency, nutrient recycling potential, and economics. In this case study, a sequencing batch constructed wetland (SBCW) was designed and added after a package treatment plant (PTP) using reactive filter media for phosphorus (P) removal and recycling. The treatment performance of the entire system in the start-up phase and its possible applicability in rural areas were investigated. Raw and treated effluents were sampled during a period of 25 weeks and analyzed for nitrogen, phosphorus, BOD 7 , and bacteria. Field measurements were made of wastewater flow, electrical conductivity, oxygen, and temperature. The entire system removed total-P and total inorganic nitrogen (TIN) by 83% and 22%, respectively. High salt concentration and very low wastewater temperature were possible reasons for these unexpectedly low P and TIN removal efficiencies. In contrast, removal rates of bacteria (Escherichia coli, enterococci) and organic matter (as BOD) were high, due to filtration in the alkaline medium Polonite ® (Ecofiltration Nordic AB, Stockholm, Sweden) and the fine sand used as SBCW substrate. High pH in effluent from the PTP was efficiently reduced to below pH 9 in the SBCW, meeting recommendations by environmental authorities in Sweden. We concluded that treating cold on-site wastewater can impair treatment performance and that technical measures are needed to improve SBCW performance.

Integrated Methods for Household Greywater Treatment: Modified Biofiltration and Phytoremediation

“…This finding is in agreement with the results reported by Haddis et al [ 70 ] and Selemani and Njau [ 71 ]. On the other hand, the lowest mean temperature (21.87 ± 0.4°C) recorded at the HSSFCW effluent could be attributed to the long HRT in the HSSFCW as well as shading effect of the vetiver grass surrounding the wetland [ 72 , 73 ]. This low temperature result at the planted CW effluent is consistent with the results reported by Ling et al [ 74 ].…”

Assessment of the Efficiency, Environmental and Economic Effects of Compact Type On-Site Wastewater Treatment Plants—Results from Random Testing

“…Biological treatment plants can be of two types: the natural based type (e.g., constructed wetland or sand filter) or the container type. Natural based systems are very effective in BOD 5 and suspended solids removal and with some modifications can also remove nutrients efficiently [36,43,44]. However, they usually have high land requirements and as since the treatment process is not controlled there, they cannot be certified.…”

“…The septic system's effect on the environment can be difficult to measure. Sustainable on-site treatment solutions must be developed to replace many of the older types that are still in use and are having undesired effects on water bodies and groundwater [36]. For the protection of the environment, the construction of new septic systems should be prohibited, and the old septic systems should be replaced by biological treatment plants.…”

Phosphate adsorption from water and wastewater using non-devulcanised and devulcanised tyre rubber

“…The removal of phosphorus from wastewater is crucial because excess phosphorus causes the eutrophication of natural water bodies. In addition to insufficiently treated wastewater, phosphates can enter the environment [ 24 , 25 ]; therefore, methods to reduce the concentration of phosphates in water from wastewater treatment plants are being devised [ 26 ]. Urban wastewater treatment plants use activated sludge.…”