Behavior ofTypha angustifoliaL. in a free water surface constructed wetlands for the treatment of swine wastewater

Abstract

The objective of this study was to evaluate the behavior of Typha angustifolia L. in nitrogen retention in a Free Water Surface Constructed Wetland (FWS) for the swine wastewater treatment over a three-year operating period. Results show that the behavior of Typha angustifolia L. in a FWS for treatment of swine wastewater is affected by nitrogen concentration, seasonal variation and plant establishment in the system. Indeed, the application of Nitrogen Loading Rates (NLR) between 7.1-14.3 kg TN/ha·d removes 40% of Total Nitrogen (TN), where the maximum removal (20-40%) takes place in the spring-summer seasons. However, concentrations higher than 120.3 mg NH4 (+)-N/L significantly decrease (P = 0.004) diametrical growth by 55%. However, it was possible to estimate that NLR >14.3 kg TN/ha·d increased biomass production and plant uptake in Typha angustifolia L. during the period analyzed. Additionally, aboveground biomass values were between 1.509.6-2.874.0 g/m(2) and nitrogen uptake 27.4-40.8 g/m(2), where this last value represents 29% of the TN applied during the study. Finally, the TN accumulation in sediments represents less than 2% of the TN incorporated during this period. These results show that an increase of 50% of the TN in sediments increases plant abundance in 73%, which is related to the mineralization processes favored in the system during the last year of operation.

Effect of variations in the nitrogen loading rate and seasonality on the operation of a free water surface constructed wetland for treatment of swine wastewater

“…In this case, over 3 years of operation, the plant N:P:K Foliar biomass presents a value of 968.6 § 10.0 g m ¡2 . Similar to the discussion above about phytotoxic effects, these values are lower than those reported for FWS operation for loads in the range of 0.2 to 69.9 kg TN ha ¡1 ¢d ¡1 , with a value of 1,509.6 § 120.2 g m ¡2 , [8] and for loads in the range of 3.0 to 40.0 kg TN ha ¡1 ¢d ¡1 , with a value of 1,100 to 2,800 g m ¡2 . [4] Evolution of the FWS sediments Figure 6 shows the accumulation of nutrients in sediments in relation to the C/N ratio during the study period.…”

“…[8] Plaza de los Reyes et al [8] reported the existence of a relation between the N: P: K ratio and the operational time of the sytem (establishment of macrophyte species). In this case, over 3 years of operation, the plant N:P:K Foliar biomass presents a value of 968.6 § 10.0 g m ¡2 .…”

“…Plant diameter and height were measured each month to assess macrophyte evolution. [8] Relative abundance (plants m ¡2 ) was estimated monthly according to Mueller-Dombois and Ellenberg. [25] Aboveground biomass was estimated and proximate analyses were carried out at the end of autumn, according to the method of Mueller-Dombois and Ellenberg.…”

“…[2,[4][5][6][7] Hunt et al [4] found total nitrogen (TN) removal in a range of 70 to 95% with NLRs between 3.0-36.0 kg TN ha ¡1 ¢d ¡1 , with the highest efficiency levels (>75%) at NLRs below 25.0 kg TN ha ¡1 ¢d ¡1 in a FWS fed with swine wastewater from an anaerobic lagoon. Plaza de los Reyes et al [8] indicated that this type of configuration can only remove between 20.0-40.0% of the applied TN, with a NLR between 7.1-14.3 kg TN ha ¡1 ¢d ¡1 .…”

Nitrogen and phosphorus distribution in a constructed wetland fed with treated swine slurry from an anaerobic lagoon

“…[18,19] Meanwhile, to end 2011 and mid 2012, it had hydraulic loading rates between 1.7 and 9.1 mm d ¡1 from rainfall. [20] The wetland system in the last period (spring 2011 to fall 2012) had nutrient loads about 3,381 kg N ha ¡1 and 1,061 kg P ha ¡1 from taken up of swine slurries by the aboveground vegetal tissue none pruned, soil and remained loads from early 2011.…”