title: Response of removal rates to various organic carbon and ammonium loads in laboratory-scale constructed wetlands treating artificial wastewater.
abstract: High levels (92 and 91%) of organic carbon were successfully removed from artificial wastewater by a laboratory-scale constructed wetland under inflow loads of 670 mg/m2 x d (100 mg/d) and 1600 mg/m2d (240 mg/d), respectively. Acidification to pH 3.0 was observed at the low organic carbon load, which further inhibited the denitrification process. An increase in carbon load, however, was associated with a significant elevation of pH to 6.0. In general, sulfate and nitrate reduction were relatively high, with mean levels of 87 and 90%, respectively. However, inhibition of nitrification was initiated with an increase in carbon loads. This effect was probably a result of competition for oxygen by heterotrophic bacteria and an inhibitory effect of sulfide (S2) toxicity (concentration approximately 3 mg/L). In addition, numbers of healthy stalks of Juncus effusus (common rush) decreased from 14 000 to 10 000/m2 with an increase of sulfide concentration, indicating the negative effect of sulfide toxicity on the wetland plants.
authors: College of Engineering, China Agricultural University, 100083 Beijing, China. wushubiao@gmail.com
authors: Shubiao
authors: S
authors: Wu
authors: Peter
authors: P
authors: Kuschk
authors: Arndt
authors: A
authors: Wiessner
authors: Matthias
authors: M
authors: Kästner
authors: Changle
authors: C
authors: Pang
authors: Renjie
authors: R
authors: Dong
mesh_terms: D002244:Carbon / Q000302:isolation & purification*; D052918:Environmental Restoration and Remediation; D009930:Organic Chemicals / Q000302:isolation & purification*; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification*; D062065:Wastewater; D053833:Wetlands
chemical_list: D002244:Carbon; D009930:Organic Chemicals; D000644:Quaternary Ammonium Compounds; D062065:Wastewater