poster - International Conference of Agricultural Engineering

NUTRIENT RETENTION IN WETLANDS USING ORNAMENTAL
PLANTS¹
ROJANE KLETECKE²*; MICHELE PICCOLI² and JOSE TEIXEIRA FILHO ²
¹Part of the thesis of first author;
² College of Agricultural Engineering, Av. Candido Rondon, 501, Campinas, SP, CEP 13083-
875, Brasil. *Corresponding author E-mail: rojane.kletecke@yahoo.com.br
Abstract
The treatment of sewage is of fundamental importance for the improvement and
maintenance of the quality from water resources. The objective of this paper is to evaluate
the retention capacity of nutrients Nitrogen (N) and Phosphorus (P) in constructed wetlands
with ornamental plants, to treat domestic effluents after passing through compartmented
anaerobic reactors (CAR). The ornamental plants used were Heliconia psittacorum (CW1)
and Cyperus alternifolius (CW2). The water quality monitoring was made in an hourly scale
and the evaluation was done in two periods: before pruning (BP) and after pruning (AP). The
evaluation of retention capacity from the variables analyzed Ammonia nitrogen (NH³ + ),
Nitrate (NO -3 ) and Total phosphorus (TP), was performed based on non-parametric statistics
using the Mann-Whitney test at 5% significance. Statistical differences were registered only
for the period BP, for the concentration and load of NO -3 , where CW1 was more efficient for
the retention, with an average of 29.8% and 31.0% respectively. The ornamental plants
contributed to the local landscape composition, reducing the rejection of persons to the
sewage treatment, transforming this place in a flooded garden, appreciated for
contemplation.
Keywords: Constructed Wetlands; Water quality; Nutrients; Domestic effluents; Flooded
garden.
1.Introduction
Water resources are being every time more degraded. Among the different factors which
contribute for this degradation are the domestic effluents. Most effluents are disposed in
natura in rivers, without any type of treatment. According to TUCCI et al. (2001), most rivers
crossing Brazilian cities are deteriorated, which is considered one of the biggest
environmental problems of the country. Within this frame, systems of constructed wetlands
(CW) are a good option for sewage treatment in small communities, horizontal
condominiums, small industries and agro-industries among others. It presents low
implantation and operational costs, minimum mechanization indices (CHERNICHARO,
2003). CWs are sustainable systems, indicated for tropical countries like Brazil. CWs are
considered biological filters where aerobic and anaerobic microorganisms, which are fixed in
the substrate and in the plants roots, are responsible for water purification reactions (WOOD,
1995). The nutrients, mainly Nitrogen (N) and Phosphorus (P), available in domestic
effluents, contribute to the eutrophication of water and CWs with ornamental plants improve
the retention of these pollutants.
2. Material and Methods
The experiment was conducted at the Experimental Field of the Agricultural Engineering
Faculty from University of Campinas (FEAGRI/UNICAMP). The geographical coordinates are
S 22º48’57” and WGr 47º03’33”, average height is 640 m. The climate, according to the
classification of Köppen, is a transition between types Cwa and Cfa, indicating that the
climate is tropical in altitude with dry winter and humid summer. The temperature of the
hottest month is above 22°C and below 18°C at the c oldest month (June). The average