Wetland construído de fluxo vertical empregado no tratamento de esgoto de um restaurante universitário

Abstract

Constructed wetlands are an attractive alternative for sewage treatment due to the potential in sewage decentralization and the lower costs of implementation and operation. This study shows the design, build, and operation of a vertical flow constructed wetland (VFCW) with 25cm of submersed parcel bed. Heliconia rostrata was the chosen macrophite for the university restaurant sewage treatment. The mean superficial loading for total suspended solids (TSS) was 0,027± 0,01 kg TSS m-2 d-1 with 1.092 m2 of superficial area. It operated for 29 days with two daily pulses of 25L over a period of one minute; once in the morning the other in the afternoon. The bed was compounded with sand (20cm, d60= ,36, d10=0,18 and U=2), gravel 0 (20cm), gravel 1 (20cm) and gravel 2 (10cm). The system demonstrated mean alkalinity (mgCaCO3 L-1) and pH affluent, 123,04 ± 67,76, 6,75 ± 1,48 and effluent, 114,88 ± 25,42, 8,84 ± 0,26 and mean reduction efficiencies of 96,48 ± 2,03 %, 92,50 ± 3,14 %, 87,75 ± 10,00 %, 72,26 ± 8,90 %, 25,72 ± 9,64 %, 92,89 ± 5,12 %, respectively for chemical oxygen demand (COD), total kjeldahl nitrogen (TKN), total nitrogen (TN), ammonium (NH4-N), total solids (TS), and TSS.