164 research outputs found
Nature-based solutions for urban agriculture in buildings: challenges and opportunities
Insight is given to food security being an actual issue of concern due to rapid growth of global population, availability of arable land and consequently increase demand of food. Some problems associated with climate change such as extreme weather and soil degradation will also affect the quality and quantity of crops. On the other hand, urban area with high population relies on rural area to supply food ingredients. The linear food system creates environmental problems such as carbon footprint for transportation and increase packaging materials waste. Current Covid-19 pandemic situation adds on pressure on developed cities with mere local agriculture such as Macao. Macao depends on mainland China for fresh fruits and vegetables supply since local production is not the main trend. Due to the above reasons, this study intents to provide a new insight on food production in urban context towards a more sustainable and healthier environment using nature-based solutions. Assessment of indoor farming feasibility in city will be carried out by literature review and business entities interviews. A survey will be developed about the public acceptance to produce food in buildings with nature-based solutions. The methodology will proceed with a state-of-the-art assessment followed by a systematic review focused on selected NBS. Statical analysis will be carried out for data assessment.info:eu-repo/semantics/publishedVersio
Resilience of green roofs to climate change
The successful management of cities growth rely in part on the maximization of the benefits delivered by the built environment while minimizing the environmental degradation. Circular and resourceful cites are the mainstream for climate change resilience. Green roofs, as a nature-based solution, contribute to climate change adaptation and mitigation through the provision of several ecosystem services. Value of green roofs can be achieved at the level of environmental (e.g., air quality enhancement, carbon sequestration, biodiversity promotion stormwater management, acoustic insulation, and noise reduction), social (e.g., esthetic integration, well-being and life quality, rooftop gardens), and economic (e.g., life span extension, energetic efficiency, energy production, real-state valorization, business development) spheres. Buildup green roof resilience maybe underpinned by the selection of efficient and sustainable components for its installation. This chapter aims at giving an overview on the role of green roofs resilience to climate change, highlighting the provision of services and the mitigation and adaption capacity.info:eu-repo/semantics/acceptedVersio
Treatment of industrial wastewater with two-stage constructed wetlands planted with typha latifolia and phragmites australis
Industrial wastewater treatment comprises several processes to fulfill the discharge permits or to enable the reuse of wastewater. For tannery wastewater, constructed wetlands (CWs) may be an interesting treatment option. Two-stage series of horizontal subsurface flow CWs with Phragmites australis (UP series)
and Typha latifolia (UT series) provided high removal of organics from tannery wastewater, up to 88% of biochemical oxygen demand (BOD5) (from an inlet of 420 to 1000 mg L-1) and 92% of chemical oxygen demand (COD) (from an inlet of 808 to 2449 mg L-1), and of other contaminants, such as nitrogen, operating at hydraulic retention times of 2, 5 and 7 days. No significant (P < 0.05) differences in performance
were found between both the series. Overall mass removals of up to 1294 kg COD ha-1 d-1 and 529 kg BOD5 h-1 d-1 were achieved for a loading ranging from 242 to 1925 kg COD ha-1 d-1 and from 126 to 900 kg BOD5 ha-1 d-1. Plants were resilient to the conditions imposed, however P. australis exceeded T. latifolia in terms of propagation.info:eu-repo/semantics/acceptedVersio
Constructed wetland systems vegetated with different plants applied to the treatment of tannery wastewater
Wastewaters from leather processing are very complex and lead to water pollution if
discharged untreated, especially due to its high organic loading. In this study the survival of different plant species in subsurface horizontal flow constructed wetlands receiving tannery wastewater was investigated. Five pilot units were vegetated with Canna indica, Typha latifolia, Phragmites australis, Stenotaphrum secundatum and Iris pseudacorus, and a sixth unit was left as an unvegetated control. The treatment performance of the systems under
two different hydraulic loading rates, 3 and 6 cmd1, was assessed. COD was reduced by
41–73% for an inlet organic loading varying between 332 and 1602 kg ha1 d1 and BOD5 was
reduced by 41–58% for an inlet organic loading varying between 218 and 780 kg ha 1 d1. Nutrient removal occurred to lower extents. Phragmites australis and Typha latifolia were the only plants that were able to establish successfully. Despite the high removal of organic content from the influent wastewater, during 17 months of operation, no significant differences in performance were observed between units
Treatment of tannery wastewater in a constructed wetlands operating in series with different plant species
The treatment of tannery wastewater has been a very important issue for pollution
control in leather producing countries due to its high pollutant content. Biological
processes offer a natural way of treating wastewaters, when compared to more
aggressive types of treatment. Constructed wetlands can be an alternative to more
conventional biological treatment systems. The species Phragmites australis, Typha spp,
Scirpus spp. and Phalaris arundinacea are some of the plants frequently used in
subsurface flow constructed wetlands.
The present study aimed at assessing the performance of constructed wetland systems
operating in series for the treatment of wastewater derived from a tannery plant. Pilot
units were operated with horizontal subsurface flow and planted with Typha latifolia and
Phragmites australis in an expanded clay matrix. They were subject to two different
hydraulic loadings: 180mm/d and 60 mm/d.
For an hydraulic loading of 180 mm/d, maximum removal efficiencies of 2100
KgCOD/had (48%) were achieved for unit 1 and 1500 KgCOD/had (33%) for unit 2. For
an hydraulic loading of 60 mm/d, maximum removal efficiencies of 360 KgCOD/had
(66%) were achieved for unit 1 and of 250 KgCOD/had (60%) for unit 2. No significant
differences in performance were found between units with different plant species
Long term application of a constructed wetland for phytoremediation of domestic wastewater: macrofauna biodiversity assessment
Constructed wetlands (CW) are engineered systems, phytoremediation based, that mimic several processes (physical, biological, and chemical) that occur in natural wetlands. They comprise several components, impermeabilization liners and substrate, and as the key elements the plants and their associated microorganisms. They were thought primarily for wastewater treatment but nowadays are considered a nature-based solution of excellence in terms of flexibility of their application and services provided. In the present study, the phytoremediation potential of a real scale constructed wetland to treat wastewater from a tourism unity is addressed. The CW was implemented in 2010 at Paço de Calheiros, a tourism house integrated in a rural area. The CW was designed to be placed after a previously installed septic tank that acted as the main treatment before the CW was established. It is a horizontal subsurface flow system planted with a polyculture of Agapanthus africanus, Canna flaccida, Zantedeschia aethiopica, Canna indica, and Watsonia borbonica. The aim of the study is to monitor the efficiency of a CW, after long term operation, based on phytoremediation processes, to treat the wastewater from the tourism unit. Wastewater quality will be assessed through the analysis of physic-chemical and microbiological parameters towards its reuse for irrigation purposes. The biodiversity of macrofauna communities associated to the rhizosphere of selected plants and substrate will be studied.info:eu-repo/semantics/publishedVersio
Toxicity abatement of wastewaters from tourism units by constructed wetlands
The present research intended to investigate the toxicity abatement of domestic wastewater after passing a biosystem composed of a constructed wetland (CW) followed by a pond. The wastewater was generated in a tourism house in a rural and mountainous context and passed through a septic tank before being diverted to a CW followed by a pond. A battery of ecotoxicological tests, comprising microalgae (Raphidocelis subcapitata), macrophytes (Lemna minor), cladocerans (Daphnia magna), and bacteria (Aliivibrio fischeri), was used to assess the toxicity of the wastewater collected before and after the CW and the water of the pond. Physicochemical parameters (pH, conductivity, chemical oxygen demand, biochemical oxygen demand, total suspended solids, phosphates, ammonium, and nitrate) were also determined. The CW was able to remove carbon and nutrients from the water with a concomitant reduction of its toxicity. This study, reinforced the added value of using toxicity tests as a complement to CW operational monitoring to validate the solution and to analyze possible readjustments that may be required to improve efficiency. This study lends further support to the claim that CWs can be a sustainable solution for treating small volumes of domestic wastewater in a rural context.info:eu-repo/semantics/publishedVersio
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