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Treatment Wetlands
Get PDFOverview of Treatment Wetlands; Fundamentals of Treatment Wetlands; Horizontal Flow Wetlands; Vertical Flow Wetlands; French Vertical Flow Wetlands; Intensified and Modified Wetlands; Free Water Surface Wetlands; Other Applications; Additional Aspects.
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Wetland Technology : Practical Information on the Design and Application of Treatment Wetlands
Get PDFWater quality standards across the world are being re-written to promote healthier ecosystems, ensure safe potable water sources, increased biodiversity, and enhanced ecological functions. Treatment wetlands are used for treating a variety of pollutant waters, including municipal wastewater, agricultural and urban runoff, industrial effluents, and combined sewer overflows, among others. Treatment wetlands are particularly well-suited for sustainable water management because they can cope with variable influent loads, can be constructed of local materials, have low operations and maintenance requirements compared to other treatment technologies, and they can provide additional ecosystem services. The technology has been successfully implemented in both developed and developing countries. The first IWA Scientific and Technical Report (STR) on Wetland Technology was published in 2000. With the exponential development of the technology since then, the generation of a new STR was facilitated by the IWA Task Group on Mainstreaming Wetland Technology. This STR was conceptualized and written by leading experts in the field. The new report presents the latest technology applications within an innovative planning framework of multi-purpose wetland design. It also includes practical design information collected from over twenty years of experience from practitioners and academics, covering experiments at laboratory and pilot-scale up to full-scale applications. Scientific and Technical Report No.2
Wetland Technology
Get PDFWater quality standards across the world are being re-written to promote healthier ecosystems, ensure safe potable water sources, increased biodiversity, and enhanced ecological functions. Treatment wetlands are used for treating a variety of pollutant waters, including municipal wastewater, agricultural and urban runoff, industrial effluents, and combined sewer overflows, among others. Treatment wetlands are particularly well-suited for sustainable water management because they can cope with variable influent loads, can be constructed of local materials, have low operations and maintenance requirements compared to other treatment technologies, and they can provide additional ecosystem services. The technology has been successfully implemented in both developed and developing countries.
The first IWA Scientific and Technical Report (STR) on Wetland Technology was published in 2000. With the exponential development of the technology since then, the generation of a new STR was facilitated by the IWA Task Group on Mainstreaming Wetland Technology. This STR was conceptualized and written by leading experts in the field. The new report presents the latest technology applications within an innovative planning framework of multi-purpose wetland design. It also includes practical design information collected from over twenty years of experience from practitioners and academics, covering experiments at laboratory and pilot-scale up to full-scale applications.
Scientific and Technical Report No.2
Performance of lagoon and constructed wetland systems for tertiary wastewater treatment and potential of reclaimed water in agricultural irrigation
Get PDFClimate change poses challenges to agricultural water resources, both in terms of quantity and quality. As an adaptation measure, the new European Regulation (EU) 2020/741 establishes different water quality classes for the use of reclaimed water in agricultural irrigation. Italy is also working on the definition of a new regulation on reclaimed water reuse for agricultural irrigation (in substitution of the current one) that will also include the specific requirements imposed by the European one. Nature-based Solutions (NBS) can be a cost-effective and environmentally friendly way to facilitate water reclamation and reuse. The present study reports the outcomes of a long-term monitoring campaign of two NBS (e.g., a constructed wetland (CW) and a lagoon system (LS)) comparing influent and effluent concentrations of different contaminants (e.g., E. coli, BOD5, TSS, TN and TP) with the threshold values imposed by the new regulations. The results showed that in both the case studies, E. coli (about 100 CFU 100 mL-1) and BOD5 (lower than 25 mg L-1) mean effluent concentration need to be further reduced in reclaimed water to be suitable for unlimited reuse. As a negative aspect, in both the monitored NBS, an increase in TSS mean concentration in the effluent was observed, up to 40 mg L-1 in the case of the LS, making reclaimed water unsuitable for agricultural reuse. The CW has proven to be more effective in nitrogen removal (the effluent mean concentration was 3.4 mg L-1), whereas the LS was better at phosphorus removal (with an effluent mean concentration of 0.4 mg L-1). Based on the results, recommendations were made to further improve the performance of both systems in order to have adequate water quality, even for class A. Furthermore, the capacity of reclaimed water to meet crop water and nutrient needs was analyzed, and total nitrogen removal rate coefficients were calculated for the design of future LSs
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Simulating vertical flow wetlands using filter media with different grain sizes with the HYDRUS Wetland Module
No full textIn this study, the simulation results of four vertical flow wetland systems using the HYDRUS Wetland Module are presented. The four wetland systems comprise three single-stage pilot scale systems and one full-scale two-stage system. The main difference between these systems is the filter media used, referred to as fine media, i.e., sand with a grain size distribution 0.063–4 mm, or coarse media, i.e., sand with grain size distributions between 1–4 mm, respectively. The water-flow simulation of each system is carried out using the single porosity van Genuchten-Mualem model. A good match between measured and simulated volumetric effluent flow rates could be achieved for all wetland systems. For reactive transport simulations, the CW2D biokinetic model was applied. First, simulations were run using the standard CW2D parameter set. For some systems, adjustments of the parameter set were needed in order to avoid unlimited bacteria growth. To better fit measured COD, NH4-N, and NO3-N effluent concentrations, adjustments of few parameters of the standard parameter set were required. The results show that for the VF wetlands with fine sand, no adjustments of the CW2D standard parameter set were needed, while for systems with coarser filter media as the main layer, the standard parameter set had to be adjusted to match simulated and measured effluent concentrations
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