Wastewater Treatment by Constructed Wetland Eco-Technology: Influence of Mineral and Plastic Materials as Filter Media and Tropical Ornamental Plants

Abstract

Constructed wetlands (CWs) are sustainable technologies where the channels are filled with porous material and plants, which collectively remove pollutants, depending on the type of substrate and vegetation. This study evaluated CWs and their functionality by comparing three ornamental plants (Canna indica, Cyperus papyrus, and Hedychium coronarium) as a phytoremediation process of wastewater, in CWs filled with layers of porous stone–tepezil–plastic residues–soil (S-A), or in microcosms with layers of porous stone–tepezil–soil without the presence of plastic (S-B). The findings during 180 days showed that the removals of pollutants (chemical oxygen demand (COD), total solids suspended (TSS), nitrogen as ammonium (N-NH4), as nitrate (N-NO3), and phosphate (P-PO4) were 20%–60% higher in microcosms with plants than in the absence of plants. Statistical differences were not observed when comparing removal effects among S-A and S-B, indicating that plastic residues as filter material in CWs did not affect the pollutant removal, growth, flowering, and shoots of plants. The use of plastic residues as filter may represent a less costly alternative in CW establishments. Dependence on N-NH4 and TSS removal was observed according to plant species. The three species used are suitable for using in CWs as wastewater treatment. In addition, the ornamental plants could generate interest for a commercial option.

Knowledge Atlas on the Relationship between Water Management and Constructed Wetlands—A Bibliometric Analysis Based on CiteSpace

“…For example, the purification efficiencies of CWs designed with ornamental plants is 93.8% for TN, 80.0% for dissolved organic carbon (DOC), 84.0% for the biochemical oxygen demand (BOD 5 ), 77.0% for the chemical oxygen demand (COD), and 99.7% for the turbidity, which not only effectively remove nutrients and improve the wastewater quality, but the cannas also bring certain landscape benefits [155]. In addition, Sergio Zamora et al used three ornamental plants (Canna indica, Cyperus papyrus, and Hedychium coronarium) as a phytoremediation process for wastewater, and they found that all three plants were able to remove more pollutants than the experimental setup without plants, which confirms that ornamental vegetation can be used in CW systems [156]. Immediately after, LC Sandoval-Herazo et al investigated the ability of ornamental plants to remove pollutants at different densities, and they showed that high-density planting facilitated the removal of 10% to 20% of the pollutants [157].…”

Are the Water Quality Improvement Measures of China’s South-to-North Water Diversion Project Effective? A Case Study of Xuzhou Section in the East Route

“…In addition to reducing emissions of pollutants at the source, it is also necessary to intercept pollutants in the transmission pathway and carry out ecological restoration of agricultural ecosystem [ 55 , 56 ]. Some ecological engineering techniques like ecological ditches, constructed wetlands, and vegetated filter strips should be applied in Xuzhou section [ 57 , 58 ]. Secondly, measures are needed to control the release of phosphorus from sediments to water.…”

Wastewater Treatment and Reuse: a Review of its Applications and Health Implications

“…They observed in their experiments about 70% of reduction in total suspended solids (TSS) and biochemical oxygen demand (BOD), 50% to 60% of reduction in nitrogen, ammonia, and phosphate levels, and a significant reduction in feacal coliform populations. Whereas, Zamora et al (2019) found the removal efficiency of chemical oxygen demand (COD), total solids suspended (TSS), nitrogen as ammonium (N-NH 4 ) and nitrate (N-NO 3 ), and phosphate (P-PO 4 ) up to…”