The Use of Constructed Wetland for Mitigating Nitrogen and Phosphorus from Agricultural Runoff: A Review

Abstract

The loss of nitrogen and phosphate fertilizers in agricultural runoff is a global environmental problem, attracting worldwide attention. In the last decades, the constructed wetland has been increasingly used for mitigating the loss of nitrogen and phosphate from agricultural runoff, while the substrate, plants, and wetland structure design remain far from clearly understood. In this paper, the optimum substrates and plant species were identified by reviewing their treatment capacity from the related studies. Specifically, the top three suitable substrates are gravel, zeolite, and slag. In terms of the plant species, emergent plants are the most widely used in the constructed wetlands. Eleocharis dulcis, Typha orientalis, and Scirpus validus are the top three optimum emergent plant species. Submerged plants (Hydrilla verticillata, Ceratophyllum demersum, and Vallisneria natans), free-floating plants (Eichhornia crassipes and Lemna minor), and floating-leaved plants (Nymphaea tetragona and Trapa bispinosa) are also promoted. Moreover, the site selection methods for constructed wetland were put forward. Because the existing research results have not reached an agreement on the controversial issue, more studies are still needed to draw a clear conclusion of effective structure design of constructed wetlands. This review has provided some recommendations for substrate, plant species, and site selections for the constructed wetlands to reduce nutrients from agricultural runoff.

Deciphering the source contribution of organic matter accumulation in an urban wetland ecosystem

“…The wetland sediments showed a high concentration of P and this may be related to the fertilizer runoff from the agricultural and horticultural fields. Additionally, the P loadings due to the ingress of sewage and effluents from STPs are the other sources of P in wetland sediments (Li et al, 2021). The fluctuations in P concentration along the sediment cores may be attributed to the retention ability of P regulated by various factors like adsorption with clay minerals, co-precipitation with manganese, iron, and calcium (Kruusement & Punning, 2000).…”

Wetland Restoration with Hydrophytes: A Review

“…Regarding flow-surface constructed wetlands [ 113 ], Ceratophyllum demersum , Hydrilla verticillata , Myriophyllum verticillatum , Vallisneria natans , and Potamogeton crispus are commonly used among the submerged plants. The commonly used free-floating hydrophytes in CWs include Lemna minor , Eichhornia crassipes , Salvinia natans , and Hyrocharis dubia .…”

Simultaneous adsorption of ammonia and phosphate using ferric sulfate modified carbon/zeolite composite from coal gasification slag

“…Water eutrophication not only impacts the aquatic ecological functions, but also affects drinking water safety and threatens human health in the world, particularly in many developing countries (Yang et al, 2012a;Yang et al, 2012b). Different methods have been developed to remove nitrogen and phosphorus, including adsorption, crystallization, ion exchange, precipitation, biological removal, and others (Li et al, 2021;Salimova et al, 2020). Among these technologies, adsorption is widely applied, because of its relatively low cost, small energy consumption, and easy implementation (Qu, 2008).…”