scholarly journals Wpływ miąższości reaktywnej warstwy drenażowej na odpływ fosforanów z zielonego dachu

2017 ◽  
Vol 26 (4) ◽  
pp. 447-456
Author(s):  
Agnieszka Karczmarczyk ◽  
Agnieszka Kocik
Keyword(s):  
Green Roof ◽  
Optimal Solution ◽  
Column Experiment ◽  
Green Roofs ◽  
Reactive Material ◽  
Drainage Layer ◽  
Roof Material ◽  
Substrate Layer ◽  
Simulated Precipitation ◽  
Water Outflow

The green roof runoff may be contaminated with phosphorus. The source of P pollution can be a substrate layer. The research was carried out to determine an optimal ratio of P-reactive drainage layer (RM) to substrate layer (S) in a green roof construction. The main goal of conducted column experiment, was to examine P-removal efficiency of drainage layers in different thickness. The green roof material used in the experiment is a commercially available substrate for intensive roofs. It has been confirmed that the substrate can act as a source of phosphorus occurring in leachate from green roofs. It has been found that the P-reactive drainage layer of Polonite® in thickness of 2 and 5 cm reduces phosphate load in runoff. The load of phosphorus discharged from the columns amounted to 0.091; 0.032 and 0.02 mg P-PO4 for K1 (S:RM=10:1), K2 (S:RM=10:2) and K3 (S:RM=10:5). Layer of the substrate relative to reactive material layer of 10: 2 was considered as an optimal solution. In relation to the quality of water supplied an increase of pH and conductivity in runoff was observed. The P-reactive drainage layer and its thickness had no effect on these parameters. All the columns reduced water outflow by approximately 40% compared to the volume of simulated precipitation.

scholarly journals Heat Transfer Measurement within Green Roof with Incinerated Municipal Solid Waste Aggregates

2021 ◽  
Vol 13 (13) ◽  
pp. 7115
Author(s):  
Mostafa Kazemi ◽  
Luc Courard ◽  
Julien Hubert
Keyword(s):  
Heat Transfer ◽  
Heat Resistance ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Green Roof ◽  
Insulation Material ◽  
Drainage Layer ◽  
Roof System ◽  
Substrate Layer ◽  
Significant Difference

A green roof is composed of a substrate and drainage layers which are fixed on insulation material and roof structure. The global heat resistance (Rc) within a green roof is affected by the humidity content of the substrate layer in which the coarse recycled materials can be used. Moreover, the utilization of recycled coarse aggregates such as incinerated municipal solid waste aggregate (IMSWA) for the drainage layer would be a promising solution, increasing the recycling of secondary resources and saving natural resources. Therefore, this paper aims to investigate the heat transfer across green roof systems with a drainage layer of IMSWA and a substrate layer including recycled tiles and bricks in wet and dry states according to ISO-conversion method. Based on the results, water easily flows through the IMSWAs with a size of 7 mm. Meanwhile, the Rc-value of the green roof system with the dry substrate (1.26 m2 K/W) was 1.7 times more than that of the green roof system with the unsaturated substrate (0.735 m2 K/W). This means that the presence of air-spaces in the dry substrate provided more heat resistance, positively contributing to heat transfer decrease, which is also dependent on the drainage effect of IMSWA. In addition, the Rc-value of the dry substrate layer was about twice that of IMSWA as the drainage layer. No significant difference was observed between the Rc-values of the unsaturated substrate layer and the IMSWA layer.

scholarly journals Legislative requirements related to substrate depth as a barrier to the construction of green roofs in Bulgaria

2020 ◽  
Vol 21 (2) ◽  
pp. 99-104
Author(s):  
Mariam Bozhilova ◽  
Miglena Zhiyanski ◽  
Plamen Glogov
Keyword(s):  
Layer Thickness ◽  
Green Roof ◽  
Green Roofs ◽  
Future Research ◽  
National Legislation ◽  
Green Area ◽  
Substrate Layer ◽  
Green System ◽  
Substrate Depth ◽  
Existing Data

There are 265 municipalities in Bulgaria. According to the national legislation, each Municipal Coun-cil adopts an Ordinance for the construction and protection of the green system. Most of the mu-nicipalities have such ordinances, however, only 75 of them stipulate regulative requirements, under which a green roof can be considered a green area. These requirements refer to the substrate depth and are unreasonably high. While positive impacts are reported in green roofs with a substrate layer thickness of 4 – 5 cm, green roofs with substrate depth under 10 cm are not considered a green area in any of the reviewed ordinances. One municipality considers green roofs with substrate 10-30 cm as a green area, under specific conditions. This paper provides a review of the stipulations of the Bulgarian local legislation against the existing data for the effects of green roofs with different substrate depths and outlines the need for amendment of the legislation and future research. 

Modular Green Roofs and their Usage in the World

2020 ◽  
Vol 47 ◽  
pp. 103-108
Author(s):  
M. Hejl ◽  
Martin Mohapl ◽  
Lukáš Bříza
Keyword(s):  
Czech Republic ◽  
Green Roof ◽  
Optimal Solution ◽  
Green Roofs ◽  
Modular System ◽  
Layer System ◽  
Construction Time ◽  
The Czech Republic ◽  
The World ◽  
Roof Panel

This article wants to introduce modular green roof systems and their usage in the world as well as in the Czech Republic, because green roofs are now used more than they have been constructed in any era in the history. Their construction is almost same as it was in previous centuries, so the obvious solution for their improvement is in the construction of themselves. Especially in the improvement of their construction time which should be lower with usage of modular system than at classical layer system of the green roofs. This research also wants to speak about construction system for individual types of green roof. Where the purpose of this article is to set optimal solution for modular green roof panel which will be economical and environmentally friendly.

scholarly journals Performance analysis and experimental study on rainfall water purification with an extensive green roof matrix layer in Shanghai, China

2017 ◽  
Vol 77 (3) ◽  
pp. 670-681 ◽  
Author(s):  
Jiankang Guo ◽  
Yanting Zhang ◽  
Shengquan Che
Keyword(s):  
Orthogonal Design ◽  
Green Roof ◽  
Green Roofs ◽  
Ammonium Nitrogen ◽  
Sodium Polyacrylate ◽  
Event Mean Concentration ◽  
Extensive Green Roof ◽  
Artificial Rainfall ◽  
Substrate Layer ◽  
Roof Experiment

Abstract Current research has validated the purification of rainwater by a substrate layer of green roofs to some extent, though the effects of the substrate layer on rainwater purification have not been adequately quantified. The present study set up nine extensive green roof experiment combinations based on the current conditions of precipitation characteristics observed in Shanghai, China. Different rain with pollutants were simulated, and the orthogonal design L9 (33) test was conducted to measure purification performance. The purification influences of the extensive green roof substrate layer were quantitatively analyzed in Shanghai to optimize the thickness, proportion of substrate, and sodium polyacrylate content. The experimental outcomes resulted in ammonium nitrogen (NH4+-N), lead (Pb), and zinc (Zn) removal of up to 93.87%, 98.81%, and 94.55% in the artificial rainfall, respectively, and NH4+-N, Pb, and Zn event mean concentration (EMC) was depressed to 0.263 mg/L, 0.002 mg/L and 0.018 mg/L, respectively, which were all well below the pollutant concentrations of artificial rainfall. With reference to the rainfall chemical characteristics of Shanghai, a combination of a 200 mm thickness, proportions of 1:1:2 of Loam: Perlite: Cocopeat and 2 g/L sodium polyacrylate content was suggested for the design of an extensive green roof substrate to purify NH4+-N, Pb and Zn.

scholarly journals The GREENROOF module (v7.3) for modelling green roof hydrological and energetic performances within TEB

2013 ◽  
Vol 6 (6) ◽  
pp. 1941-1960 ◽  
Author(s):  
C. S. de Munck ◽  
A. Lemonsu ◽  
R. Bouzouidja ◽  
V. Masson ◽  
R. Claverie
Keyword(s):  
Water Content ◽  
Green Roof ◽  
Green Roofs ◽  
Model Interaction ◽  
Drainage Layer ◽  
Extensive Green Roof ◽  
Hydrological Characteristics ◽  
Drainage Layers ◽  
The Impact

Abstract. The need to prepare cities for climate change adaptation requests the urban modeller community to implement sustainable adaptation strategies within their models to be tested against specific city morphologies and scenarios. Greening city roofs is part of these strategies. In this context, the GREENROOF module for TEB (town energy balance) has been developed to model the interactions between buildings and green roof systems at the scale of the city. This module, which combines the ISBA model (Interaction between Soil Biosphere and Atmosphere) and TEB, allows for one to describe an extensive green roof composed of four functional layers (vegetation – grasses or sedums; substrate; retention/drainage layers; and artificial roof layers) and to model vegetation-atmosphere fluxes of heat, water and momentum, as well as the hydrological fluxes throughout the substrate and the drainage layers, and the thermal fluxes throughout the natural and artificial layers of the green roof. TEB-GREENROOF (SURFEX v7.3) should therefore be able to represent the impact of climate forcings on the functioning of green roof vegetation and, conversely, the influence of the green roof on the local climate. An evaluation of GREENROOF is performed for a case study located in Nancy (France) which consists of an instrumented extensive green roof with sedums and substrate and drainage layers that are typical of this kind of construction. After calibration of the drainage layer hydrological characteristics, model results show good dynamics for the substrate water content and the drainage at the green roof base, with nevertheless a tendency to underestimate the water content and overestimate the drainage. This does not impact too much the green roof temperatures, which present a good agreement with observations. Nonetheless GREENROOF tends to overestimate the soil temperatures and their amplitudes, but this effect is less important in the drainage layer. These results are encouraging with regard to modelling the impact of green roofs on thermal indoor comfort and energy consumption at the scale of cities, for which GREENROOF will be running with the building energy version of TEB – TEB-BEM. Moreover, with the green roof studied for GREENROOF evaluation being a type of extensive green roof widespread in cities, the type of hydrological characteristics highlighted for the case study will be used as the standard configuration to model extensive green roof impacts at the scale of cities.

scholarly journals Should You Put Your Energy Into Green Roofs to Reduce Energy Consumption in Your Building

2008 ◽  
Vol 3 (2) ◽  
pp. 26-40 ◽  
Author(s):  
Brad Bass
Keyword(s):  
Energy Consumption ◽  
Urban Areas ◽  
Green Roof ◽  
Green Roofs ◽  
Building Envelope ◽  
Root Penetration ◽  
Environmental Technology ◽  
Drainage Layer ◽  
Growing Medium ◽  
Reduce Energy Consumption

Green roofs are touted as an environmental technology for urban areas due to their many benefits (Lundholm et al. 2008). Although the design and the benefits have been reported in many reports and articles, they are reviewed here for those who are unfamiliar with this technology. Green roofs, or more formally, green roof infrastructure, is a technology that allows for the growth of vegetation on a roof while protecting the building envelope from leakage and root penetration. A green roof is more than a layer of soil piled on the roof, planted in the way that you might plant a garden. The technology consists of multiple layers that include the plants and growing medium or substrate, but also a drainage layer for storing water that was not used by the plants and a waterproof, root-repellent membrane (Figure 1).

A field study to evaluate the impact of different factors on the nutrient pollutant concentrations in green roof runoff

2013 ◽  
Vol 68 (12) ◽  
pp. 2691-2697 ◽  
Author(s):  
Xiaochen Wang ◽  
Xinhua Zhao ◽  
Chenrui Peng ◽  
Xinbo Zhang ◽  
Jianghai Wang
Keyword(s):  
Plant Density ◽  
Green Roof ◽  
Green Roofs ◽  
Roof Runoff ◽  
Substrate Layer ◽  
Pollutant Concentrations ◽  
Rain Events ◽  
First Flush Effect ◽  
The Impact ◽  
Dual Substrate

The objectives of this study are to investigate the impact of different factors on the nutrient pollutant concentrations in green roof runoff and to provide reference data for the engineering design of dual substrate layer green roofs. The data were collected from eight different trays under three kinds of artificial rains. The results showed that except for total phosphorus, dual substrate layer green roofs behaved as a sink for most of the nutrient pollutants (significant at p < 0.05), and the first-flush effect did not occur during the 27 simulated rain events. The results also revealed that the concentration of these nutrient pollutants in the runoff strongly depended on the features of the nutrient substrates used in the green roof and the depth of the adsorption substrates. Compared with the influence of the substrates, the influence of the plant density and drainage systems was small.

scholarly journals A two-stage storage routing model for green roof runoff detention

2013 ◽  
Vol 69 (6) ◽  
pp. 1191-1197 ◽  
Author(s):  
Gianni Vesuviano ◽  
Fred Sonnenwald ◽  
Virginia Stovin
Keyword(s):  
Green Roof ◽  
Volumetric Flow Rate ◽  
Green Roofs ◽  
Storm Event ◽  
Storm Events ◽  
Two Stage ◽  
Drainage Layer ◽  
Main Components ◽  
Almost All

Green roofs have been adopted in urban drainage systems to control the total quantity and volumetric flow rate of runoff. Modern green roof designs are multi-layered, their main components being vegetation, substrate and, in almost all cases, a separate drainage layer. Most current hydrological models of green roofs combine the modelling of the separate layers into a single process; these models have limited predictive capability for roofs not sharing the same design. An adaptable, generic, two-stage model for a system consisting of a granular substrate over a hard plastic ‘egg box’-style drainage layer and fibrous protection mat is presented. The substrate and drainage layer/protection mat are modelled separately by previously verified sub-models. Controlled storm events are applied to a green roof system in a rainfall simulator. The time-series modelled runoff is compared to the monitored runoff for each storm event. The modelled runoff profiles are accurate (mean Rt2 = 0.971), but further characterization of the substrate component is required for the model to be generically applicable to other roof configurations with different substrate.

scholarly journals Role of drainage layer on green roofs in limiting the runoff of rainwater from urbanized areas

2019 ◽  
Vol 41 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Anna M. Baryła
Keyword(s):  
Moisture Content ◽  
Green Roof ◽  
Initial Moisture Content ◽  
Green Roofs ◽  
Climatic Conditions ◽  
Column Studies ◽  
Initial State ◽  
Drainage Layer ◽  
Urbanized Areas ◽  
Substrate Moisture

Abstract Green roofs play a significant role in sustainable drainage systems. They form absorbent surfaces for rainwater, which they retain with the aid of profile and plants. Such roofs therefore take an active part in improving the climatic conditions of a city and, more broadly, the water balance of urbanized areas. One of the factors influencing the hydrological efficiency of green roofs is the drainage layer. In the article, column studies were carried out under field conditions involving the comparison of the retention abilities of two aggregates serving as the drainage layer of green roofs, i.e. Leca® and quartzite grit. The average retention of the substrate was 48%; for a 5 cm drainage layer of Leca® retention was 57%, for a 10 cm layer of Leca average retention was 61%. For a 5 cm layer of quartzite grit average retention was 50%, for 10 cm layer of quartzite grit 53%. The highest retention was obtained for the column with the substrate and 10-centimeter layer of Leca®. At the same time, it was shown that Leca® is a better retention material than quartzite grit. The initial state of substrate moisture content from a green roof appears to be a significant factor in reducing rainfall runoff from a green roof; the obtained values of initial moisture content made for a higher correlation than the antecedent dry weather period.

The use of reactive material for limiting P-leaching from green roof substrate

2016 ◽  
Vol 73 (12) ◽  
pp. 3027-3032 ◽  
Author(s):  
Agnieszka Bus ◽  
Agnieszka Karczmarczyk ◽  
Anna Baryła
Keyword(s):  
Water Quality ◽  
Urban Areas ◽  
Water Retention ◽  
Green Roof ◽  
Column Experiment ◽  
Phosphorus Concentration ◽  
Reactive Material ◽  
Average Value ◽  
Supporting Layer ◽  
P Leaching

Abstract The aim of the study is to assess the influence of drainage layer made of reactive material Polonite® on the water retention and P-PO4 concentration in runoff. A column experiment was performed for extensive substrate underlined by 2 cm of Polonite® layer (SP) and the same substrate without supporting layer as a reference (S). The leakage phosphorus concentration ranged from 0.001 to 0.082 mg P-PO4·L−1, with average value 0.025 P-PO4·L−1 of S experiment and 0.000–0.004 P-PO4·L−1 and 0.001 P-PO4·L−1 of SP experiment, respectively. The 2 cm layer of Polonite® was efficient in reducing P outflow from green roof substrate by 96%. The average effluent volumes from S and SP experiments amounted 61.1 mL (5.8–543.3 mL) and 46.4 mL (3.3–473.3 mL) with the average irrigation rate of 175.5 mL (6.3–758.0 mL). The substrate retention ability of S and SP experiments was 65% and 74%, respectively. Provided with reactive materials, green roof layers implemented in urban areas for rain water retention and delaying runoff also work for protection of water quality.

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