Efficiency of a constructed wetland for wastewaters treatment

Abstract

Aim: The limnological characteristics of three different inlets water of the constructed wetland were compared in terms of concentration data and loading rate data and evaluated the removal efficiencies of nutrients, solids, BOD 5 , chlorophyll-a and thermotolerant coliforms (TC) by the treatment system; Methods: The constructed wetland, measuring 82.8 m 2 and with detention time of 1 hour and 58 minutes in the rainy season and 2 hours and 42 minutes in the dry one, was provided with four species, Cyperus giganteus Vahl, Typha domingensis Pers., Pontederia cordata L. e Eichhornia crassipes (Mart.) Solms. The sampling sites evaluated in the dry (D) and rainy (R) seasons were: inlet water from aquaculture farm = IA; inlet channel of rainwater runoff = IR; inlet from UASB wastewater = IB; outlet wetland = OUT. The conductivity, pH, temperature, dissolved oxygen, alkalinity, BOD 5 , total soluble and dissolved solids, nitrogen, phosphorus, chlorophyll-a and TC were analyzed. Multivariate analyses, such as Cluster and Principal Components Analysis (PCA), were carried out to group sampling sites with similar limnological characteristics; Results: In the PCA with the concentration data was retained 90.52% variability of data, correlating the inlet IB with high concentrations of conductivity, alkalinity, pH, TC, nutrients and solids. Regarding loading rate data, the PCA was retained 80.9% of the data's total variability and correlated the sampling sites IA D, IA R and OUT R with higher BOD 5 , chlorophyll-a, TDS, nitrate, nitrite, total-P, temperature, oxygen and water flow. The highest removal efficiencies rates occurred in the dry season, mainly in concentration, with 78% of ammonia, 95.5% of SRP, 94.9% of TSS and 99.9% of TC; Conclusions: The wetland was highly efficacious in the removal of nutrients, solids, BOD 5 , chlorophyll-a and TC, mainly during the dry season. The system restructuring to increase the detention time during the rainy season and a pre-treatment of UASB wastewater, can increase the retention of nutrients and solids by wetland.

Developing Horizontal Subsurface Flow Constructed Wetland using Pumice and Chrysopogon zizanioides for Tannery Wastewater Treatment

“…The result reported after 10 days of operational period, water hyacinth showed maximum removal of 55.6% on 6th day, 48.7% using water lettuce on 7th day and 39.6 % on 3rd day under Vetiver treatment system (Abinaya et al, 2018). Another study also was carried on constructed wetland to treat an aquaculture effluent using four species, Cyperus giganteus Vahl, Typha domingensis Pers., Pontederia cordata L. e Eichhornia crassipes in Brazil, in this study the constructed wetland perform 85.5% removal of total dissolved solid (Travaini and Sipauba, 2012).…”

Importance of Optimum Water Quality Indices in Successful Frog Culture Practices

“…The constructed wetlands are tools used for the treatment of waste in aquaculture whose physical, chemical, and biological processes together with the local climatic conditions can improve the effluent quality [57,68]. The importance of the implementation of these systems for the treatment of fish farming effluents in Brazil is due to the fact that many producers release water directly into natural streams and rivers [69], and the organic load exceeds its capacity of support and resilience [70].…”

“…According to Travaini-Lima and Sipaúba-Tavares [68], the removal of phosphate compounds is associated to the hydraulic flow of the system, retention time, and the macrophyte species used, and species such as Cyperus giganteus, Typha domingensis, and Eichhornia crassipes are resistant and highly effective plants for subtropical regions. Sipaúba-Tavares and Boyd [74] verified that the wetland installed in an aquaculture farm containing only the aquatic plant E. crassipes presented efficiency in the removal of nitrogenous and phosphate compounds, improving the water quality of the effluent and also confirming that the system of biofiltration can be applied in shallow water channels.…”

“…Due to the need to treat the effluent from aquaculture practices, the use of "wetlands" constructed in a growing way in the country has been studied to minimize the impacts produced by these aquatic organisms [63,66,68,69]. The aquatic plants extract or take out nutrients and other substances from the surrounding water which are necessary for their development, besides requiring low capital, low operating cost and versatility in the removal mechanism than conventional treatments.…”

Diagnóstico y remoción de contaminantes emergentes en aguas superficiales y cloacales

“…Sin embargo se determinó un p-valor de 0,001, comparando los valores de pH efluentes de los sistemas plantados y los no plantados, indicando una diferencia estadísticamente significativa. Se determinó que el pH en los sistemas plantados disminuye respecto del afluente y de los sistemas no plantados, debido posiblemente a la intervención de procesos biológicos extras para la descomposición del material vegetal, lo cual eleva la cantidad de CO 2 libre en la columna de agua (Travaini and Sipaúba, 2012). Es importante resaltar que los niveles promedio de pH de los sistemas plantados, como no plantados, se encontraron dentro de los limites aceptados (4-8) para un buen desarrollo de los microorganismos (Hijosa-Valsero et al, 2010).…”