『Abstract
his paper presents the results of using a pilot-scale-constructed
wetland as a tertiary system to simulate the treatment conditions
of wastewater effluents from the metal-mechanical industry, aiming
to achieve the Brazilian legal standards of phosphorus and nitrogen
emission. The macrophytes were placed in 1 m3 polyethylene
tanks, daily estimating the treatment of 2 m3 of effluents.
The effluents were circulated in a horizontal subsurface flow
through a porous matrix of thick sand and gravel, in which the
roots of the macrophytes of the species Reed (Scirpus sp.)
and Cattail (Typha sp.) were fixed. Monitoring of the pilot
plant was performed through a battery of physical-chemical and
biological analyses. Despite the load variations and operational
problems, the system presented a positive degree of pollutant
efficiency removal, especially for phosphorus (73％ medium), TK
(61％ medium), and NH4-N (56％ medium). Peak
results were achieved during the last 3 months of monitoring.
The chemical analysis of the support layer, plus the root system
and aerial portion of the plants, revealed that these wastes could
be used as fertilizer.
Keywords: Constructed wetland; Metal-mechanical industry; Tertiary
system; Phosphorus; Nitrogen』
1. Introduction
2. Material and methods
2.1. Project and operation
2.2. Samples and analyses
2.3. Characterization of aquatic plant wastes
2.4. Statistical analyses
3. Results and discussion
3.1. Operational problems and system maintenance
3.2. Removal of nitrogen and phosphorus
3.2.1. Effect of the temperature
3.2.2. Effect of the seasons
3.2.3. Destination of aquatic plant wastes
4. Conclusion
4.1. Recommendations
References