Ultrashort Hydraulic Retention Time of Aeration and Nonaeration Constructed Wetlands for a Large Volume of Primary-Treated Wastewater from a Medical Rubber Glove Factory

A substantial volume of primary-treated wastewater from a medical rubber glove factory caused public freshwater to become sewage. e ultrashort hydraulic retention time in constructed wetlands was urgently employed for wastewater remediation. Pilotscale, aeration, and nonaeration horizontal surface �ow constructed wetlands (HSFCWs) with emergent plants were designed, compared, and optimized. Activated carbon, coconut shells, and oyster shells were subsequently transferred into a plastic basket as a substrate layer, while Typha angustifolia L. was used as an emergent plant. e experiments were conducted at a hydraulic retention time of 2, 4, 6, and 8 hr. per euent recirculation. Sampling data were collected for each of the four euent recirculations. e removal eciencies of BOD, COD, FOG, TKN, TSS, TDS, EC, and salinity in the aeration HSFCWs were high—53.25, 67.28, 97.93, 78.93, 95.87, 87.52, 86.36, and 90.38%—at the ¢rst euent recirculation of sampling, respectively, while the removal eciencies in the nonaeration HSFCWs were also high—55.12, 57.38, 94.62, 83.10, 95.95, 88.09, 89.54, and 93.46%, respectively. Increasing the hydraulic retention time increased removal eciencies. e removal eciency of BOD in aerated HSFCWs was higher than in nonaerated HSFCWs in the second euent recirculation of sampling. is is because the oxygen supplied by aeration in the system increased the organic and inorganic pollutant removal eciencies. Other pollutants were removed more e¥ectively during the second euent recirculation. Excluding BOD and COD, Duncan’s multiple test revealed that the number of euent recirculations for removal eciencies of FOG, TKN, TSS, TDS, EC, and salinity was nonsigni¢cant at the p ≤ 0.001 level. ese ¢ndings led to optimization of the medical rubber glove wastewater treatment at an ultrashort hydraulic retention time of 2–4 hr. is process and the control of CWs may be the best industrial wastewater treatment practice and a longterm solution for the industrial sector.