LIFE Project

REHABILITATION OF A HEAVY METAL CONTAMINATED RIVERBED BY PHYTOEXTRACTION TECHNIQUE. 

The riverbed of the Guadalentin River in Lorca are contaminated with heavy metals, this is mainly from industries, farms and agriculture. The Guadalentin Valley between Lorca and Murcia is characterised by intensive crop and pig production, and an extensive agroalimentary and tannery industry. These anthropogenic sources have released salts and metals into Guadalentin River, increasing the natural concentrations caused by physical and chemical weathering of rocks in the catchment area of the river. These economical activities are physically located in the whole valley, including the margins of the Guadalentin riverbanks. Traditionally the employed techniques to recover contaminated sediments in rivers have focused on physical and chemical ex-situ techniques, as solidification, soil washing, etc. In the last decades in Europe initiatives and plans in relation to contaminated soils have been carried out, although the use of phytoextraction to reclaim contaminated rivers has been scarcely used.
In this sense, in Murcia Province there are not available studies or experiences on rehabilitation of contaminated river sediments. Phytoremediation is an emerging technology that uses plants to clean up pollutants (i.e. metals, salts and organics) from the environment. Within this field of phytoremediation, the utilization of plants to transport and concentrate metals from the soil into the harvestable parts of roots and above-ground shoots is usually called phytoextraction. Most traditional remediation methods do not provide acceptable solutions for the removal of metals from soils. By contrast, phytoextraction of metals is a cost-effective approach that uses metalaccumulating plants to clean up these soils. Plants can accumulate heavy metals essential for growth and development such as Fe, Mn, Zn, Cu, Mg, Mo, and Ni. In addition, some of them have the capacity to accumulate heavy metals with no known biological functions, such as Cd, Cr, Pb, Co, Ag, Se and Hg. Subsequently, the harvestable parts, rich in accumulated metals, can be easily and safely processed by drying, ashing or composting. Some extracted metals can also be reclaimed from the ash, generating recycling revenues. Phytoextraction appears a very promising technology for the removal of metal pollutants from the environment and may be, at present, approaching comercialization.
The LIFE Riverphy project consists in the rehabilitation of heavy metal contaminated riverbed, in the Guadalentin river at the city of Lorca, by phytoextraction technique. This project, funded by the European Union through the LIFE + program, has as its beneficiaries the Subdirección General de Calidad Ambiental (Coordinator), belonging to the Consejería de Presidencia of the Comunidad Autónoma de la Región de Murcia, and the Subdirección General de Medio Natural of the same Department, Universidad Politécnica de Cartagena, the Ayuntamiento de Lorca and the Confederación Hidrográfica del Segura. The project duration is from October 1, 2012 to March 31, 2018. The total budget is € 1,714,651.00, being the EU contribution of € 835,622.00.

OBJECTIVES

The main objective of this project is to evaluate, demonstrate and disseminate a sustainable alternative for the environmental and landscape rehabilitation of a stretch of the contaminated river Guadalentín after its flow along the industrial area and urban  nucleus of Lorca. Riverbed and banks soils are contaminated, and vegetation cover is degraded owing to former direct waste spills coming from industries (mainly tanneries), farms (swine) and agriculture (excess of fertilization with swine slurries). The project will achieve this objective by using the technique of phytoextraction, which contributes to transfer heavy metals and excess of nutrients from soils to plants (which will be removed from the system periodically), and the recovery of native vegetation cover to restore the natural communities of flora and fauna, mitigating soil erosion as well. With the decrease of heavy metals and salts in soil, and restoration of riparian vegetation we will achieve the reestablishment of a stable ecological equilibrium that is coordinated with its surroundings in order to attain ecological holism, taking always into account the role of local population  and traditional activities for their integration in the landscape restoration. In order to achieve the main objective “implementing methods for rehabilitation of a stretch of the contaminated river Guadalentin by means of phytoextraction”, the detailed objectives can be summarized as follows:

1. To reclaim contaminated soils from riverbed and banks using the technique of phytoextraction. With this, several selected accumulator native plant species will be used to uptake metals and ions from the sediments. Plants will be periodically removed for metals final disposal, and new plants will be planted to replace the removed ones.
2. To protect slopes, by means of techniques of bioengineering and landscape integration, and restore native vegetation cover in riversides and slopes, to mitigate the erosion process and recuperate the ecological equilibrium of the ecosystem.
3. Energetic management of the residual contaminated biomass generated in phytoextraction actions and recovery of the extracted metals to be incorporated in the manufacturing of other product,  such  as concrete.
4. To monitor the evolution of soil properties (mainly metals and ions), as well as vegetation in the restored area.
5. To rehabilitate landscape based on ecological planning and design.
6. To disseminate and transfer the experience and knowledge generated at provincial, national and European level by means of public information and manual technique adapted to different stakeholders.

EXPECTED RESULTS

The main result of this project is the decontamination of a contaminated riverbed by former wastes spills and dumps and the riparian vegetation recuperation by means of the phytoextraction technique. The project will improve soil physical, chemical and biological conditions, reducing the contents in heavy metals and salts, which guarantee the development of microbial communities and plant colonization, essential to soil functioning. In the whole, we will achieve a landscape restoration based on ecological and aesthetic criteria. The main final objective of the Project is the ecological rehabilitation of the riverbed and banks, extracting the heavy metals and eliminating the current bound risks for environment and population, permitting the final development of vegetation and the restoration of the ecosystem. Monitoring of soil and vegetation properties and plant colonization will be carried out until total ecological stabilisation of plant species and soil fertility is increased enough to maintain the vegetation, even if this stabilization is gotten post project. In addition, the maintenance of the rehabilitated area will be carried out indefinitely. This will be possible because the local administration will fund the activities of monitoring and maintenance to reduce the environmental risk of the river stretch and increase the population welfare. The plant producers will support these activities in order to find new contaminated areas to apply phytoextraction, which increase the potential use of vegetation for this purpose.

BENEFICIARIES

Coordinator

• Dirección General de Medio Ambiente. Consejería de Presidencia de la Región de Murcia (CARM). C/ Catedrático Eugenio Úbeda, 3, 4º planta. 30071 Murcia

Associated

• Grupo de Gestión, Aprovechamiento y Recuperación de Suelos y Aguas (GARSA) Universidad Politécnica de Cartagena Plaza Cronista Isidro Valverde. Edificio “La Milagrosa”. 30202 Cartagena (Murcia)
• Ayuntamiento de Lorca.  Plaza de España, 1. 30800 Lorca (Murcia)
• Confederación Hidrográfica del Segura.  Plaza Fontes, 1. 30001 Murcia

ACTIONS

• Preparatory actions  (A)

Acción A1. Preliminary activities

• Implementation actions  (B)

Action B1. Initial characterization of soils and vegetation

Action B2. Phytoextraction in sediments

Action B3. Slopes protection and revegetation

Action B4. Energetic use of residual contaminated biomass

Action B5. Evolution of soils and vegetation

Action B6. Environmental recovery and landscape design

• Monitoring the impacts of the project actions  (C)

Action C1. Monitoring the effectiveness of true soil rehabilitation

Action C2. Monitoring the socioeconomic impact

• Communication and Dissemination actions  (D)

Action D1. Dissemination and Communication Plan

Action D2. Public website

Action D3. Notice boards

Action D4. Publication of information/publicity material

Action D5. Technical visits

Action D6. Training course

Action D7. Workshops and seminars

Action D8. Assistance to fairs and conferences

• Project management and monitoring of the  project progress  (E)

Action E1. Project  Management

Action E2. Networking with other projects

Action E3. Audit

Action E4. After LIFE Communication Plan.

GLOSARIO

Biomass Organic matter originated in a spontaneous or induced biological process that can be usable for as a potential energy source.

Decontaminate To make something safe by removing, neutralizing, or destroying any harmful substance.

Phytoextraction Absorption of contaminant metals by plant roots and their accumulation in stems and leaves.

Phytoremediation  Soil decontamination, wastewater treatment or indoor air cleaning, using vascular plants, algae (phytorremediation) or fungi (mycoremediation), and ecosystem containing these plants.

Heavy metals Group of chemical elements that have a relatively high density and some toxicity to humans. Some may represent a serious environmental problem. The best known are mercury, lead, cadmium and thallium. It also usually includes a semimetal as arsenic and, in some cases, some non-metal such as selenium.

Restoration Degraded, damaged or destroyed ecosystem reestablishment. The objective of ecological restoration is the conservation and replenishment of natural capital, as well as restitution of ecosystem services for the society use and enjoyment.