title: Polishing domestic wastewater on a subsurface flow constructed wetland: organic matter removal and microbial monitoring.
abstract: Microbial monitoring of constructed wetlands (CWs) treating domestic wastewater is generally scarce, despite the need of more knowledge about its biocenosis. The sanitation quality of a wastewater treated in a CW is a crucial aspect, mainly when the receiving water body is used as a swimming and/or recreation area. The present study was carried out in a horizontal subsurface flow CWplanted with Phragmites australis receiving pre-treated domestic wastewater (mean flow 50 m3 day(-1)), from a population of about 300 inhabitants. The monitoring programme undertaken during the first year operation, revealed removal efficiencies of 61% BOD5, 44% COD, and 65% TSS for inlet water with ca. 90 mg L(-1) BOD5, 157 mg L(-1) COD, and 17 mg L(-1) TSS. Total Coliform (TC) and Faecal Coliform (FC) bacteria were removed from wastewater (mean inlet values of 5 x 10(6) CFU 100 mL(-1) TC and of 9 x 10(5) CFU 100 mL(-1) FC), with efficiencies of 92 and 97%, respectively. The dynamics of microbial communities established in the system assessed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), had revealed a high bacterial diversity within the system, with no relevant differences in composition at the CW inlet and outlet but exhibiting temporal differences in bacterial communities.
authors.affiliation: CITAB/Departamento de Biologia-Escola de Ciêkncias, Universidade do Minho (DB-ECUM), Campus de Gualtar, Braga, Portugal. icapmina@bio.uminho.pt
authors.forename: I
authors.initials: I
authors.lastname: Aguiar-Pinto Mina
authors.forename: M
authors.initials: M
authors.lastname: Costa
authors.forename: A
authors.initials: A
authors.lastname: Matos
authors.forename: C
authors.initials: C
authors.lastname: Sousa Coutinho Calheiros
authors.forename: P M L
authors.initials: PM
authors.lastname: Castro
mesh_terms: D001419:Bacteria / Q000254:growth & development* / Q000302:isolation & purification; D001673:Biodegradation, Environmental; D058448:Biota; D016000:Cluster Analysis; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis; D058645:Denaturing Gradient Gel Electrophoresis; D004784:Environmental Monitoring; D007220:Industrial Waste / Q000032:analysis*; D006109:Poaceae / Q000254:growth & development / Q000378:metabolism*; D011174:Portugal; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013997:Time Factors; D014865:Waste Disposal, Fluid; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*; D053833:Wetlands
chemical_list: D004269:DNA, Bacterial; D007220:Industrial Waste; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S