Differences in the treatment efficiency of a cold-resistant floating bed plant receiving two types of low-pollution wastewater

Abstract

A floating bed system vegetated with Oenanthe javanica was adopted in this study to treat two types of low-pollution wastewater (LPW): polluted river water (PRW) and treated domestic wastewater (DW). The water was treated for 111 days during the low-temperature season. The results indicated that the total nitrogen (TN) removal rates were higher in the DW groups than in the PRW groups during the initial 30 days. This difference may stem from the different C/N ratio of the influent. As the water temperature rose above 15.5 °C after March 12, the purification capability of nitrogen in the DW groups was enhanced, and the removal rates of TN were 89.8 and 76.8 % in DW and the control 2 at 111 days. Conversely, the performance of total phosphorus (TP) removal was robust during the initial stage of the experiment, despite receiving domestic wastewater with a relatively high N/P ratio (16:1). The TP removal rates in DW were as high as 91.5 % compared to 78.9 % in PRW at 30 days. At the same time, the N/P ratios of plant tissue were higher in the DW groups compared to that in the PRW groups. Plant uptake played a significant role in nutrient removal in the PRW groups (52.5 % for TN, 68.2 % for TP), followed by sedimentation. In contrast, plant uptake only accounted for 25.3 % of TN removal and 24.1 % of TP removal in DW. The results provide engineering parameters for the future design of an ecological remediation technology for LPW purification.

The biomass accumulation and nutrient storage of five plant species in an in-situ phytoremediation experiment in the Ningxia irrigation area

“…The water conductivity and pH values indicated that soil salinization and alkalization may have resulted in saline and alkaline agricultural drainage water. The water conductivity and pH were lower than the values recorded in the simulation experiment 20 , suggesting that the presence of plants could be used to mitigate alkaline and saline conditions 29 .…”

“…Duan et al . 29 observed that the removal efficiency of TP reached 78.9% and the uptake by O . javanica accounted for 68.2% of the total removal when the TP concentration was 0.9 mg/L in the Tai Lake region.…”

“…In addition to Japan 1 , the United States 13,25 and Australia 28 , phytoremediation has also been reported to be widely applied in China 29,30 , and primarily in southern China because that the rice cultivation is mainly located in southern areas. For example, Kumwimba et al .…”

Nutrient removal of a floating plant system receiving low- pollution wastewater: Effects of plant species and influent concentration

“…After ultraviolet sterilizing, DW was diluted to high or low concentration by tap water before use (namely, H groups and L groups, respectively). The wastewater used in the experiment was a kind of lowpollution wastewater (LPW), which met the Chinese Farm Irrigation Water Standard [10]. The characteristics of the experimental water were exhibited in Table 1.…”

A New Green Model for the Bioremediation and Resource Utilization of Livestock Wastewater

“…Plant uptake may have played a major role in P removal in this study, as the sediments did not adsorb P from the LW, but instead released it. Duan et al showed that plant uptake by water dropwort was responsible for 68.81% of TP removal from polluted river water, which was much more than that of sedimentation (23.70%) [57]. Thus, the water dropwort-constructed wetland in this study had a strong tolerance to high nutrient conditions and a high P efficiency, although the TP concentrations of the LW remained stable.…”