Nitrogen removal from landfill leachate in constructed wetlands with reed and willow: Redox potential in the root zone

Abstract

a b s t r a c tThis study investigated the effects of reed and willow on bioremediation of landfill leachate in comparison with an unplanted control by measuring redox potential levels in the rhizosphere of microcosm systems in a greenhouse. Plants had a significant influence on redox potential relative to the plant-less system. Redox potential in the reed rhizosphere was anoxic (mean À102 AE 85 mV), but it was the least negative, being significantly higher than in the willow (mean À286 AE 118 mV), which had the lowest Eh. Redox potential fluctuated significantly in the willow rhizosphere during daylight hours, with large decreases in the morning. Levels of NH 4 þ decreased significantly in the first day of the experiment and remained at similar low levels in all three variants for the next four weeks of the experiment. Following this removal of ammonia significant peaks in NO 2 À occurred in the control and reed tanks on the 1st day, and again on 14th day in the control tank up to 13 mg/dm 3 . In the willow tank there was also one significant peak of NO 2 À in the first week, but only up to 0.5 mg/dm 3 . Significant accumulation, within 21 days of NO 3 À in all variants was observed, but in tanks with reed and willow the concentration of NO 3 À remained significantly lower (<4 mg/dm 3 ) than in the unplanted tank (w35 mg/dm 3 ). Final levels of total-nitrogen, nitrate and chemical oxygen demand were considerably lower in the reed and willow tank than in the unplanted tank.

Sustainable treatment of landfill leachate

“…They also claimed that organic loading and ammonia were the factors that affected the biodegradation. In another work, Białowiec et al (2012) compared reed and willow with an unplanted control by measuring redox potential levels in the rhizosphere of microcosm system for the leachate bioremediation. The results suggested that redox potential in the reed rhizosphere was anoxic (mean -102 ± 85 mV), but it was the least negative, being significantly higher than in the willow (mean -286 ± 118 mV), which had the lowest Eh.…”

Adsorption Studies of Leachate on Cockle Shells

“…To meet discharge standards, the conventional methods that generate residues are saddled with high initial and operational costs and low applicability to a wide variety of pollutants, among others [14][15][16][17][18][19][20][21]. In recent years, an increasing number of research looks into the potential application of other adsorbents (e.g., agricultural waste or natural polymers and by-products of industrial processes) to achieve appropriate leachate treatment or as an alternative approach to conventional media for the treatment of pollutants that exist wastewater.…”

Growth and efficiency of nutrient removal by Salix jiangsuensis J172 for phytoremediation of urban wastewater

“…Ultimately,75.39 and 84.90 % NO 3 − -N was removed, respectively. Previous studies reported that Salix could remove large amounts of N and P in constructed wetlands (Wu et al 2011;Białowiec et al 2012). In the present study, similar trends were observed.…”

“…The application of economic plants for wastewater phytoremediation includes constructed wetlands (Białowiec et al 2012;Leto et al 2013;Türker et al 2013), a hydroponic nutrient film technique system (Vaillant et al 2002(Vaillant et al , 2003Hu et al 2008), and a floating mat economic plant-based treatment system (Sooknah and Wilkie 2004;Sun et al 2009;Li et al 2014).…”

“…During the last two decades, many researchers in the field of wastewater renovation by wetland systems have focused on the use of short-rotation willows (Weih and Nordh 2002;Mant et al 2003;Dimitriou and Aronsson 2011;Dimitriou and Rosenqvist 2011;Nissim et al 2014). A variety of systems based on constructed wetlands planted with willows (Börjesson and Berndes 2006;Wu et al 2011;Białowiec et al 2012) have been established to treat wastewater. However, these systems take up large areas of land and only a small fraction of the total quantity of nutrients are removed from the wastewater (Amofah et al 2012).…”