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Ecological Engineering 37 (2011) 663–665

Contents lists available at ScienceDirect

Ecological Engineering

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The 3rd International Symposium on Dynamics and Controlf Pollutants in Wetlands (WETPOL 2009), co-organised by theepartment of Hydraulics, Maritime and Environmental Engi-eering at the Technical University of Catalonia (UPC, Barcelona,pain) and the Institute of Environmental Assessment and Wateresearch (IDAEA-CSIC, Barcelona, Spain), was held 20–24 Septem-er 2009 in Barcelona, Spain. The WETPOL 2009 Symposium wasfollow-up of the previous ones held in Ghent (Belgium, 2005)

nd Tartu (Estonia, 2007) that considered similar process-basedopics on pollutant dynamics in both natural and constructedetlands. Advances in scientific aspects related to pollutant

emoval processes and fate in natural wetlands and wetlands con-tructed for pollution control were the main objectives of thisymposium.

Specific Symposium topics were:

Spatial and temporal redox changes in wetlandsRole of wetlands in pollutant management at catchment scaleImpact of global changes in wetlandsTrace elements in wetlands: mobility and sequestrationBehavior of priority and emerging pollutants in wetlandsMolecular and microbial advances related to pollutant fate, dis-posal, and removal in wetlandsRole of wetland plants in pollution controlPollutant modelling in wetlandsTechnological developments in constructed wetlandsHydraulic behavior and hydrological processes in wetlandsAssessment of clogging processes in constructed wetlandsRole of substrate in pollutant removalWetlands and water reuseDewatering and stabilization of sludge in constructed wetlands

Over 250 participants from 38 countries attended WETPOL009, with a total of 5 plenary and 5 keynote lectures presented tohe full auditorium, as well as 100 oral and 115 poster presentationsffered in parallel sessions. The plenary lectures were presented

y Eloy Bécares (Spain), Yong Cai (USA), Peter Kuschk (Germany),atrick J. Megonigal (USA), and Carlos Vale (Portugal). Duringhe Symposium, a technical visit was made to the Aiguamolls de

� Based on selected papers presented at the 3rd International Symposium onynamics and Control of Pollutants in Wetlands (WETPOL 2009), 20–24 September009, Barcelona, Spain.

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’Empordà Natural Reserve, the wastewater treatment plant ofmpuriabrava, and the constructed wetlands of Empuriabrava (alln the province of Girona, Spain).

This special issue of the journal Ecological Engineering and onepecial issue of the International Journal of Environmental Analyticalhemistry include selected peer-reviewed papers presented at theymposium and will constitute a key output of the conference.

The main topics of this special issue of Ecological Engineer-ng concentrate on: (1) the role of microorganisms and plantselated to pollutant fate, disposal, and removal; (2) new techno-ogical developments and design in constructed wetlands usedor treatment of different types of wastewaters; (3) dewateringnd mineralization of sludge in constructed wetlands; and (4)he role of wetlands in pollutant management at river catchmentcale.

In natural wetlands as well as constructed wetlands, microor-anisms play a major role in ecosystem health and in theegradation of contaminants. However, the role and influence thathe microbiological regime has on specific aspects, especially inonstructed wetlands, have been given little attention. In this sense,he work of Weber and Legge (2011) explores the interactionsetween microbial communities, plants and hydrological dynamics

n constructed wetland mesocosms. Another more classical pro-edure for studying microorganisms in wetlands focuses on theirctivities. García-Lledó et al. (2011) developed a new type of incu-ation chamber to report on nitrate reduction activities, and theirelationship with plant coverage in a field-scale wetland. Measuredctivities in chambers were well above the removal efficiencies ofhe field-scale system. Zhou et al. (2011) developed an experimento test the effect of infiltration rate on nitrogen dynamics in a forageice paddy soil, with 15N as tracer element. The results showed thatigh infiltration rates enhanced nitrification and denitrificationrocesses, while low infiltration rates were beneficial to assimila-ion, adsorption, and immobilization of nitrogen. González-Alcarazt al. (2011) used an experimental approach to test under labora-ory conditions the effect of vegetation on denitrification reactionsaking place in different loam mine wastes with different pHnd heavy metal vegetation. Results suggested that revegetationf salt marshes polluted by acidic sandy mining wastes mightmprove the capacity of this type of environment to act as a green

lter.

The effect of plant species on removal efficiency in constructedetlands has been the subject of a good number of studies over

he past years. The paper presented by Taylor et al. (2011) evalu-

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64 Editorial / Ecological En

ted plant effects on seasonal patterns of organic carbon removalnd sulfate in replicated, batch-loaded greenhouse microcosms.ineteen plants species and unplanted controls were used forxperiments. Better performing species were largely in the fam-lies Cyperaceae and Juncaceae, while poorer performing species

ere largely in the Poaceae. Dan et al. (2011) evaluated theotential of using the plant Sebasnia sesban in multistage con-tructed wetland systems treating high-strength wastewaters. Theesults of these studies on plant effects suggest that novel speciesan be as good or better than those typically used in treat-ent wetlands. Borin et al. (2011) report on evapotranspiration

ates of Phragmites australis in constructed wetland mesocosmsocated in two distinct regions. A water balance approach wassed and crop coefficients are derived. The plants were foundo make a significant contribution to evapotranspiration losses,hich has to be taken in account for design purposes of treatmentetlands.

A broad range of wastewaters can be treated in constructed wet-ands. The most typical application is urban wastewater treatment,or which developments made over the last years have allowedhe construction of complex multistage systems. However, themplementation of these systems at field scale and their opera-ion and management are not always straightforward, as describedn the case study presented by Brix et al. (2011). A modifica-ion of the concept of the multistage constructed wetland has ledo the development of novel semi-intensive subsurface infiltra-ion systems with a low energy footprint and low surface areaeeds. This is the case of the system presented by Lloréns et al.2011) which is able to remove carbon as well as nitrogen upo 90%. Certain agro-industrial wastewaters, such as those pro-uced by wineries, constitute a serious environmental problem.ultistage constructed wetland systems can be used again for the

reatment of these wastewaters. However, as winery wastewa-ers are quite concentrated, a previous anaerobic step was usedn the work by Serrano et al. (2011) in order to prevent rapid clog-ing of the wetlands. The combination of anaerobic reactors andultistage constructed wetland systems seems to be a growing

lternative for treatment of a great variety of industrial efflu-nts. The problem of clogging has been intensively studied in veryecent years, and different methods for assessing the degree oflogging have appeared. In the study of Pedescoll et al. (2011),t is proved that the falling head method for hydraulic conduc-ivity measurement is a reliable technique for on-site cloggingvaluation, and that it is able to discriminate among hydrauliconductivities generally recorded for non-clogged and cloggedacilities.

Brovelli et al. (2011) developed a methodology for hori-ontal flow constructed wetland design that circumvents thessumptions of homogeneous porous medium and plug flow. Thisethodology can be used during the design phase as well as

o optimize existing systems. This type of work highlights theey role that will be played by numerical models in the nearuture in the design, operation, and maintenance of constructedetlands.

Sewage sludge is the main organic waste or by-product gener-ted in wastewater treatment plants (WWTPs). Its management isighly complex and accounts for 20% to 60% of the total operatingosts of treatment plants. For this reason, sludge management is aatter of concern in many countries, and the use of sludge treat-ent wetlands is a promising sustainable alternative. In this sense,

eruzzi et al. (2011) and Bianchi et al. (2011) explored the sludge

tabilization process in different sludge treatment systems usingonventional and nonconventional methods (such as dehydroge-ase activity and abundance of pyrolytic fragments). Heavy metalioavailabity is a very important property with respect to reuse of

Z

ing 37 (2011) 663–665

he sludge as final product, which was also studied by Peruzzi et al.2011).

Information concerning the consequences of the channeliza-ion of rivers is presented in the paper by Glinska-Lewczuk andurandt (2011). The authors studied the water quality in semi-loticnd lentic cut-offs, and proved that maintenance of the connec-ion between the downstream arm of the cut-off channel andhe river is highly recommended. Obolewski (2011) observed innobstructed oxbow lakes that the main components of benthicauna were Crustacea, while Ephemeroptera were found mostlyn the water body connected to the river via a drainage chan-el. The results indicated that hydrological connectivity was theain factor responsible for the structure of invertebrate popula-

ions, followed by the physical and chemical parameters of the localnvironment.

The articles published in this special issue of the journal Ecolog-cal Engineering highlight the essential and distinguishing feature

ETPOL Symposium, which brings together scientists and tech-icians working in natural and constructed wetlands. This allows

or exchange of information on methodologies, experiences andltimately knowledge that will allow to advance in the field ofcological Engineering.

Thanks very much to Ruthmarie Mitsch and the Elsevier staffnvolved in the editorial process of the present issue.

eferences

ianchi, V., Peruzzi, E., Masciandaro, G., Ceccanti, B., Ravelo, S.M., Iannelli, R., 2011.Efficiency assessment of a reed bed pilot plant (Phragmites australis) for sludgestabilisation in Tuscany (Italy). Ecol. Eng. 37, 779–785.

orin, M., Milani, M., Salvato, M., Toscano, A., 2011. Evaluation of Phragmites australis(Cav.) Trin. Evapotranspiration in Northern and Southern Italy. Ecol. Eng. 37,721–728.

rix, H., Koottatep, T., Fryd, O., Laugesen, C.H., 2011. The flower and the butterflyconstructed wetland system at Koh Phi Phi–System design and lessons learnedduring implementation and operation. Ecol. Eng. 37, 729–735.

rovelli, A., Carranza-Diaz, O., Rossi, L., Barry, D.A., 2011. Design methodologyaccounting for the effects of porous medium heterogeneity on hydraulic res-idence time and biodegradation in horizontal subsurface flow constructedwetlands. Ecol. Eng. 37, 758–770.

an, T.H., Quang, L.N., Chiem, N.H., Brix, H., 2011. Treatment of high-strengthwastewater in tropical constructed wetlands planted with Sesbasnia ses-ban: horizontal subsurface flow versus vertical downflow. Ecol. Eng. 37,711–720.

arcía-Lledó, A., Ruiz-Rueda, O., Vilar-Sanz, A., Sala, L., Baneras, J., 2011. Nitrogenremoval efficiencies in a free water surface constructed wetland in relation toplant coverage. Ecol. Eng. 37, 678–684.

linska-Lewczuk, K., Burandt, P., 2011. Effect of river straightening on the hydro-chemical properties of flood plain lakes: observations from the Łyna and DrwecaRivers, N Poland. Ecol. Eng. 37, 786–795.

onzález-Alcaraz, M.N., Egea, C., María-Cervantes, A., Jiménez-Carceles, F.J., Álvarez-Rogel, J., 2011. Effects of eutrophic water flooding on nitrate concentrations inmine wastes. Ecol. Eng. 37, 693–702.

loréns, M., Pérez-Marín, A.B., Aguilar, M.I., Sáez, J., Ortuno, J.F., Meseguer, V.F., 2011.Nitrogen transformation in two subsurface infiltration systems at pilot scale.Ecol. Eng. 37, 736–743.

bolewski, K., 2011. Macrozoobenthos patterns along environmental gradients andhydrological connectivity of oxbow lakes. Ecol. Eng. 37, 796–805.

edescoll, A., Samsó, R., Romero, E., Puigagut, J., García, J., 2011. Reliabil-ity, repeatability and accuracy of the falling head method for hydraulicconductivity measurements under laboratory conditions. Ecol. Eng. 37,754–757.

eruzzi, E., Masciandaro, G., Macci, C., Doni, S., Ravelo, S.G.M., Peruzzi, P., Ceccanti,B., 2011. Heavy metal fractionation and organic matter stabilization in sewagesludge treatment wetlands. Ecol. Eng. 37, 771–778.

errano, L., de la Varga, D., Ruíz, I., Soto, M., 2011. Winery wastewater treatment ina hybrid constructed wetland. Ecol. Eng. 37, 744–753.

aylor, C.R., Hook, P.B., Stein, O.R., Zabinsky, C.A., 2011. Seasonal effects of 19 plantspecies on COD removal in subsurface treatment wetland microcosms. Ecol. Eng.37, 703–710.

eber, K.P., Legge, R.L., 2011. Dynamics in the bacterial community-level physiolog-

ical profiles and hydrological characteristics of constructed wetland mesocosmsduring start-up. Ecol. Eng. 37, 666–677.

hou, S., Sugawara, S., Riya, S., Sagehasshi, M., Toyota, K., Terada, A., Hosomi, M.,2011. Effect of infiltration rate on nitrogen dynamics in paddy soil after high-load nitrogen application containing 15N tracer. Ecol. Eng. 37, 685–692.

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Editorial / Ecological En

Joan García ∗

Department of Hydraulics, Maritime andEnvironmental Engineering, Technical University of

Catalonia, c/Jordi Girona 1-3, Mòdul D-1, 08034Barcelona, Spain

ing 37 (2011) 663–665 665

∗ Tel.: +34 93 401 6464; fax: +34 93 401 7357.

E-mail address: joan.garcia@upc.edu

28 January 2011Available online 26 March 2011