The knowledge on the performance enhancement of nitrogen and organic matter in the expanded constructed wetlands (CWs) with various new designs, configurations, and technology combinations are still not sufficiently summarized. A comprehensive review is accordingly necessary for better understanding of this state-of-the-art-technology for optimum design and new ideas. Considering that the prevailing redox conditions in CWs have a strong effect on removal mechanisms and highly depend on wetland designs and operations, this paper reviews different operation strategies (recirculation, aeration, tidal operation, flow direction reciprocation, and earthworm integration), innovative designs, and configurations (circular-flow corridor wetlands, towery hybrid CWs, baffled subsurface CWs) for the intensifications of the performance. Some new combinations of CWs with technologies in other field for wastewater treatment, such as microbial fuel cell, are also discussed. To improve biofilm development, the selection and utilization of some specific substrates are summarized. Finally, we review the advances in electron donor supply to enhance low C/N wastewater treatment and in thermal insulation against low temperature to maintain CWs running in the cold areas. This paper aims to provide and inspire some new ideas in the development of intensified CWs mainly for the removal of nitrogen and organic matter. The stability and sustainability of these technologies should be further qualified.

• Klíčová slova
• Constructed wetlands, Operation strategy, Performance enhancement, Wastewater treatment,
• MeSH
• dusík chemie   MeSH
• mokřady * MeSH
• odpad tekutý - odstraňování metody   MeSH
• odpadní voda analýza   MeSH
• organické látky chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• dusík MeSH
• odpadní voda MeSH
• organické látky MeSH

Sludge treatment wetlands (STWs) are widely used to treat surplus sludge in recent years. However, the effects of plant species and loading rates on sludge characteristics in earthworm assistant STWs remain unclear. In the current study, six STWs planted with two plant species (Phragmites australis, Typha angustifolia) were investigated under four loading rates (60, 80, 90 and 120 kg DS/m2/yr) regarding the influence on sludge characteristics. Furthermore, earthworms were added in three STWs to evaluate their role on sludge stabilization during resting period. Results showed that the best sludge dewatering (dry solids (DS) of 45.0%) and stabilization (volatile solids to total solids (VS/TS) of 40.5%) were determined in the P. australis STWs at the loading rate of 80 kg DS/m2/yr. Furthermore, VS/TS and Escherichia coli contents in earthworm STWs were 5.5-11.2% and 12-39% lower than that in the control without earthworm addition. Meanwhile, earthworm also decreased the nutrient contents in STWs. However, earthworms had insignificant effects on heavy metal contents in STWs. Nevertheless, the bioavailability of Cd and Cr in STWs were decreased by earthworm addition, with an acid-soluble fraction of Cd and Cr reduced by 11.2-18% and 2.5-7.5%, respectively. In conclusion, sludge characteristics can be improved by earthworm addition in P. australis STWs.

• Klíčová slova
• Earthworms, Loading rates, Plant species, Sludge treatment, Sludge treatment wetlands,
• MeSH
• lipnicovité MeSH
• mokřady MeSH
• odpadní vody * MeSH
• Oligochaeta * MeSH
• orobincovité MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• odpadní vody * MeSH

The present study aimed to develop a pilot-scale integrated system composed of anaerobic biofilter (AF), a floating treatment wetland (FTW) unit, and a vertical flow constructed wetland coupled with a microbial fuel cell (CW-MFC) and a reactive bed filter (RBF) for simultaneously decentralized urban wastewater treatment and bioelectricity generation. The first treatment stage (AF) had 1450 L and two compartments: a settler and a second one filled with plastic conduits. The two CWs (1000 L each) were vegetated with mixed plant species, the first supported in a buoyant expanded polyethylene foam and the second (CW-MFC) filled with pebbles and gravel, whereas the RBF unit was filled with P adsorbent material (light expanded clay aggregate, or LECA) and sand. In the CW-MFC units, 4 pairs of electrode chambers were placed in different spacing. First, both cathode and anode electrodes were composed of graphite sticks and monitored as open circuit. Later, the cathode electrodes were replaced by granular activated carbon (GAC) and monitored as open and closed circuits. The combined system efficiently reduced COD (> 64.65%), BOD5 (81.95%), N-NH3 (93.17%), TP (86.93%), turbidity (94.3%), and total coliforms (removal of three log units). Concerning bioenergy, highest voltage values were obtained with GAC electrodes, reaching up to 557 mV (open circuit) and considerably lower voltage outputs with closed circuit (23.1 mV). Maximum power densities were obtained with 20 cm (0.325 mW/m2) and 30 cm (0.251 mW/m2). Besides the electrode superficial areas, the HRT and the water level may have influenced the voltage values, impacting DO and COD concentrations in the wastewater.

• Klíčová slova
• Bioenergy, Floating treatment wetlands, Local reuse, Phytoremediation, Wastewater reclamation,
• MeSH
• čištění vody * MeSH
• elektřina MeSH
• elektrody MeSH
• mokřady MeSH
• odpadní voda MeSH
• zdroje bioelektrické energie * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• odpadní voda MeSH

The first experiments on the use of wetland plants to treat wastewaters were carried out in the early 1950s by Dr. Käthe Seidel in Germany and the first full-scale systems were put into operation during the late 1960s. Since then, the subsurface systems have been commonly used in Europe while free water surface systems have been more popular in North America and Australia. During the 1970s and 1980s, the information on constructed wetland technology spread slowly. But since the 1990 s the technology has become international, facilitated by exchange among scientists and researchers around the world. Because of the need for more effective removal of ammonia and total nitrogen, during the 1990 s and 2000s vertical and horizontal flow constructed wetlands were combined to complement each other to achieve higher treatment efficiency. Today, constructed wetlands are recognized as a reliable wastewater treatment technology and they represent a suitable solution for the treatment of many types of wastewater.

• MeSH
• biodegradace MeSH
• mokřady * MeSH
• odpad tekutý - odstraňování metody   MeSH
• pohyb vody MeSH
• regenerace a remediace životního prostředí metody   MeSH
• znečištění vody analýza   statistika a číselné údaje   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Rural communities in central and eastern Europe usually use constructed wetlands (CWs) to treat domestic wastewater. Effluents from these systems are regularly discharged to receiving water, resulting in a potential transfer of pharmaceuticals and personal care products (PPCPs) from sewage to the aquatic environment. In this study, the seasonal occurrence, removal and risk assessment of 32 multi-class PPCPs were investigated in three CWs from the village of south Bohemia, Czech Republic. Among the PPCPs considered, 25 compounds were detected in sewage influent, and ibuprofen, caffeine and paracetamol were the most commonly detected PPCPs. The removal efficiencies of PPCPs in the rural CWs exhibited large variability with 11-100% for anti-inflammatories, 37-99% for β-blockers and 18-95% for diuretics. The statistical results revealed significant correlations between removal efficiencies of six PPCPs and conventional water quality parameters. The ecotoxicological assessment study revealed that most of the PPCPs (except ibuprofen) in the effluent yielded low aquatic risk. This study suggested that constructed wetlands could be effective for removing PPCPs and reducing environmental risk of PPCPs discharged from rural communities into surface water systems.

• Klíčová slova
• Environmental risk, Pharmaceuticals and personal care products, Small community, Treatment wetlands,
• MeSH
• chemické látky znečišťující vodu analýza   MeSH
• hodnocení rizik MeSH
• léčivé přípravky analýza   MeSH
• mokřady MeSH
• monitorování životního prostředí MeSH
• odpad tekutý - odstraňování * MeSH
• odpadní voda analýza   MeSH
• venkovské obyvatelstvo MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• léčivé přípravky MeSH
• odpadní voda MeSH

Chloroform is one of the common disinfection byproducts, which is not susceptible to degradation and poses great health concern. In this study, the chloroform removal efficiencies and contributions of sorption, microbial degradation, plant uptake, and volatilization were evaluated in six model constructed wetlands (CWs). The highest chloroform removal efficiency was achieved in litter-added CWs (99%), followed by planted (46-54%) and unplanted CWs (39%). Mass balance study revealed that sorption (73.5-81.2%) and microbial degradation (17.6-26.2%) were the main chloroform removal processes in litter-added CWs, and that sorption (53.6-66.1%) and plant uptake (25.3-36.2%) were the primary contributors to chloroform removal in planted CWs. Around 60% of chloroform got accumulated in the roots after plant uptake, and both transpiration and gas-phase transport were expected to be the drivers for the plant uptake. Sulfate-reducing bacteria and methanogens were found to be the key microorganisms for chloroform biodegradation through cometabolic dechlorination, and positive correlations were observed between functional genes (dsrA, mcrA) and biodegradation rates. Overall, this study suggests that wetland is an efficient ecosystem for sustainable chloroform removal, and that plant and litter can enhance the removal performance through root uptake and microbial degradation stimulation, respectively.

• MeSH
• adsorpce MeSH
• Bacteria genetika   metabolismus   MeSH
• bakteriální geny MeSH
• biodegradace MeSH
• biotransformace MeSH
• chemické látky znečišťující vodu analýza   MeSH
• chloroform chemie   MeSH
• čištění vody * MeSH
• kinetika MeSH
• mokřady * MeSH
• poločas MeSH
• volatilizace MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• chloroform MeSH

Iron is present in all types of wastewater; however, besides acid mine drainage, where it is a major constituent of concern, it is usually neglected in other types of wastewaters. In all kinds of constructed wetlands, iron plays important role in removal of organics and phosphorus, and it has an impact on transformation of nitrogen, sulfur, and metals. The biogeochemistry of iron is well understood in natural wetlands, but knowledge about iron impact on microbiological and chemical transformations during wastewater treatment in constructed wetlands is very limited. So far, the sparse research in this area provides limited information on observed interactions with several varying parameters across the studies, making it difficult to draw fundamental and mechanistic conclusions. A critical review of the complex biogeochemical networking of iron in CWs is therefore necessary to fill the gap in knowledge on the role of iron and its biogeochemical multi-interactions in wastewater treatment processes of CWs. This review is the first with specific focus on iron, discussing its mitigation and retention in CWs with different configurations and operational strategies, and presenting both seasonal dynamics and the potential remobilization of Fe. It also comprehensively discusses the interactions of redox-controlled iron turnover with the biogeochemical processes of other elements, for example, carbon (C), nitrogen (N), phosphorus (P), sulfur (S), and heavy metals. The health response of wetland plants to both deficiency and toxicity of Fe in CWs designed with specific treatment targets has also been evaluated. Due to the complexity of various wastewater compositions and microredox gradients in the root rhizosphere in CWs, future research needs have also been identified.

• MeSH
• dusík MeSH
• mokřady * MeSH
• odpad tekutý - odstraňování MeSH
• odpadní voda * MeSH
• železo MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• dusík MeSH
• odpadní voda * MeSH
• železo MeSH

The hybrid systems were developed in the 1960s but their use increased only during the late 1990 s and in the 2000s mostly because of more stringent discharge limits for nitrogen and also more complex wastewaters treated in constructed wetlands (CWs). The early hybrid CWs consisted of several stages of vertical flow (VF) followed by several stages of horizontal flow (HF) beds. During the 1990 s, HF-VF and VF-HF hybrid systems were introduced. However, to achieve higher removal of total nitrogen or to treat more complex industrial and agricultural wastewaters other types of hybrid constructed wetlands including free water surface (FWS) CWs and multistage CWs have recently been used as well. The survey of 60 hybrid constructed wetlands from 24 countries reported after 2003 revealed that hybrid constructed wetlands are primarily used on Europe and in Asia while in other continents their use is limited. The most commonly used hybrid system is a VF-HF constructed wetland which has been used for treatment of both sewage and industrial wastewaters. On the other hand, the use of a HF-VF system has been reported only for treatment of municipal sewage. Out of 60 surveyed hybrid systems, 38 have been designed to treat municipal sewage while 22 hybrid systems were designed to treat various industrial and agricultural wastewaters. The more detailed analysis revealed that VF-HF hybrid constructed wetlands are slightly more efficient in ammonia removal than hybrid systems with FWS CWs, HF-VF systems or multistage VF and HF hybrid CWs. All types of hybrid CWs are comparable with single VF CWs in terms of NH4-N removal rates. On the other hand, CWs with FWS units remove substantially more total nitrogen as compared to other types of hybrid constructed wetlands. However, all types of hybrid constructed wetlands are more efficient in total nitrogen removal than single HF or VF constructed wetlands.

• Klíčová slova
• Horizontal flow, Hybrid constructed wetlands, Industrial wastewater, Nitrogen, Organics, Vertical flow,
• MeSH
• amoniak MeSH
• biodegradace MeSH
• design vybavení MeSH
• dusík MeSH
• mokřady * MeSH
• odpad tekutý - odstraňování metody   MeSH
• odpadní voda * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• amoniak MeSH
• dusík MeSH
• odpadní voda * MeSH

The processes that affect removal and retention of nitrogen during wastewater treatment in constructed wetlands (CWs) are manifold and include NH(3) volatilization, nitrification, denitrification, nitrogen fixation, plant and microbial uptake, mineralization (ammonification), nitrate reduction to ammonium (nitrate-ammonification), anaerobic ammonia oxidation (ANAMMOX), fragmentation, sorption, desorption, burial, and leaching. However, only few processes ultimately remove total nitrogen from the wastewater while most processes just convert nitrogen to its various forms. Removal of total nitrogen in studied types of constructed wetlands varied between 40 and 55% with removed load ranging between 250 and 630 g N m(-2) yr(-1) depending on CWs type and inflow loading. However, the processes responsible for the removal differ in magnitude among systems. Single-stage constructed wetlands cannot achieve high removal of total nitrogen due to their inability to provide both aerobic and anaerobic conditions at the same time. Vertical flow constructed wetlands remove successfully ammonia-N but very limited denitrification takes place in these systems. On the other hand, horizontal-flow constructed wetlands provide good conditions for denitrification but the ability of these system to nitrify ammonia is very limited. Therefore, various types of constructed wetlands may be combined with each other in order to exploit the specific advantages of the individual systems. The soil phosphorus cycle is fundamentally different from the N cycle. There are no valency changes during biotic assimilation of inorganic P or during decomposition of organic P by microorganisms. Phosphorus transformations during wastewater treatment in CWs include adsorption, desorption, precipitation, dissolution, plant and microbial uptake, fragmentation, leaching, mineralization, sedimentation (peat accretion) and burial. The major phosphorus removal processes are sorption, precipitation, plant uptake (with subsequent harvest) and peat/soil accretion. However, the first three processes are saturable and soil accretion occurs only in FWS CWs. Removal of phosphorus in all types of constructed wetlands is low unless special substrates with high sorption capacity are used. Removal of total phosphorus varied between 40 and 60% in all types of constructed wetlands with removed load ranging between 45 and 75 g N m(-2) yr(-1) depending on CWs type and inflow loading. Removal of both nitrogen and phosphorus via harvesting of aboveground biomass of emergent vegetation is low but it could be substantial for lightly loaded systems (cca 100-200 g N m(-2) yr(-1) and 10-20 g P m(-2) yr(-1)). Systems with free-floating plants may achieve higher removal of nitrogen via harvesting due to multiple harvesting schedule.

• MeSH
• biodegradace MeSH
• chemické látky znečišťující vodu analýza   metabolismus   MeSH
• čištění vody přístrojové vybavení   metody   MeSH
• mokřady * MeSH
• odpad tekutý - odstraňování přístrojové vybavení   metody   MeSH
• sloučeniny dusíku analýza   metabolismus   MeSH
• sloučeniny fosforu analýza   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• sloučeniny dusíku MeSH
• sloučeniny fosforu MeSH

Arsenic (As) is a toxic metalloid that poses a potential risk to the environment and human health. In this study, drinking water treatment residue (DWTR) and ceramsite-based vertical flow constructed wetlands (VFCWs) were built to purify As-containing wastewater. As a method of bioaugmentation, arbuscular mycorrhizal fungi (AMF) was inoculated to Pteris vittata roots to enhance the As removal of the VFCWs. The results showed that the As removal rates reached 87.82-94.29% (DWTR) and 33.28-58.66% (ceramsite). DWTR and P. vittata contributed 64.33-72.07% and 7.57-29% to the removal of As, while AMF inoculation intensified the As accumulation effect of P. vittata. Proteobacteria, the main As3+ oxidizing bacteria in the aquatic systems, dominated the microbial community, occupying 72.41 ± 7.76%. AMF inoculation increased As-related functional genes abundance in DWTR-based wetlands and provided a reliable means of arsenic resistance in wetlands. These findings indicated that the DWTR-based VFCWs with AMF inoculated P. vittata had a great purification effect on As-containing wastewater, providing a theoretical basis for the application of DWTR and AMF for As removal in constructed wetlands.

• Klíčová slova
• Arbuscular mycorrhizal fungi, Arsenic functional gene, Arsenic pollution, Drinking water treatment residue, Vertical flow constructed wetlands,
• MeSH
• arsen * MeSH
• kořeny rostlin mikrobiologie   MeSH
• lidé MeSH
• mokřady MeSH
• mykorhiza * MeSH
• odpadní voda MeSH
• pitná voda * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• arsen * MeSH
• odpadní voda MeSH
• pitná voda * MeSH