High efficiency Phyto(co)remediation Technology as a Prompt Strategy Against Chemical Pollution of Water

Project leaders

Massimo Zacchini, Maritsa Kurashvili

Agreement

GEORGIA - SRNSF - Shota Rustaveli National Science Foundation

Call

CNR/SRNSF biennio 2018-2019 2018-2019

Department

Earth system science and environmental technologies

Thematic area

Earth system science and environmental technologies

Status of the project

New

Research proposal

Human activity is steadily connected with the production and application of different chemical compounds, whose release in the environment has resulted in the ecosystem contamination and risks for human health. The development of environmental sustainable methods for soil and water remediation from pollutants is a challenging problem. Pharmaceuticals and personal care products (PPCPs) are becoming an emerging problem due to their wide occurrence in both fresh and reclaimed waters. PPCPs are present at trace concentrations in surface waters, gaining the classification of micro-contaminants. Little information is available in the literature about the toxicological effects of these compounds, the effective concentrations and persistence in the environment, and toxicity of their metabolites. Organochlorine pesticides are very dangerous chemical pollutants being included in a list of 10 most dangerous compounds by the Agency for Toxic Substances and Disease Registry (USA). These compounds belong to Persistent Organic Pollutants (POPs) having high chemical stability and low biotic and abiotic transformation. They are easily accumulated in plants and animal tissues inducing the irreversible pathological changes as nerve tissues damage, cancer and endocrine diseases. Heavy metal (HM) release in the environment may occur from metalliferous soils or due to anthropogenic activities as the mine exploitation and chemical industry. HMs are highly toxic for biota altering the cell redox state and causing mutagenic and carcinogenic processes. The accumulation of such pollutants in the natural resources and along the food chain is considered a great concern for the ecosystem and human health. Therefore, a pressing demand for their decontamination and the mitigation of the related risks is exerted worldwide. Among available technologies, an increasing demand is posed for environmental sustainable ones (naturally-based) able to exploit the ability of biological organisms to grow and accumulate/degrade contaminants in polluted substrates (Phytoremediation, Phytorem). Phytorem includes different methodological approaches, depending on the purpose. The nature and concentration of toxicants, and the substrate type, are crucial factors in approaching the phytorem application. Major concerns are posed worldwide on the contamination of freshwater and wastewater. In fact, the increasing concentration of pollutants in water bodies represents a serious threat for the survival of the aquatic ecosystem and the maintenance of high quality water reservoir to satisfy the enhancing request for safe water. In this context, due to water shortage, the use of wastewater for non domestic use as crop irrigation is increasing, enhancing the request for wastewater treatment technologies reducing the risk of pollutant transfer to plants and to the food chain. Therefore, the use of phytorem can address the demand for a low cost, low energy requesting wastewater decontamination together with the biomass production for bioenergy or biopolymers. The present project proposal focused on two model species of the aquatic ecosystem such as the macrophyte Lemna spp. and the blue-green alga Spirulina. Based on the capability of such biological organisms to tolerate and accumulate/degrade contaminants, the proposal aims at studying the most suitable conditions for the application of both the phyto- and the phyco-remediation (phyto(co)remediation) technologies and give useful indications for their application in actual conditions.
Duckweed (Lemna spp.) are photosynthetic aquatic organisms, free-floating tiny macrophytes, naturally growing in wetlands, including highly contaminated water bodies. Lemna are commonly utilised in water quality biomonitoring, in standardised tests for environmental risk assessment, proposed as a biological tool for wastewater reclamation. Duckweed represent an important community of primary producers in freshwater, estuarine and wetland ecosystems. Monitoring the responses of such plants for pollutant tolerance and accumulation/degradation, and biotransformation product release, is crucial for understanding both the environmental risk posed by pollutants and the potential of Lemna for phytoremediation.
Blue-green alga Spirulina (Spirulina platensis) has interesting prospects for phytoremediation of polluted waters. Spirulina cultivation and biomass production are cost-effective and can be obtained also in extreme environmental conditions. Its particular protein and peptide content is very suited to bind HMs and conjugate organic pollutant metabolites. During aging, Spirulina cells are inflated with air and its colonies float onto the water surface, making easy their removal from water. Only few information is present on the use of Spirulina for HM removal. Thus, the evaluation of Spirulina's ecological potential, tolerance and detoxification ability for HMs and organics, represents a novelty in the xenobiochemistry. The definition of a high efficiency biotechnology, based on application of Spirulina, for remediation of polluted waters is a novel approach to water decontamination.
The goal of the proposal is to investigate on the effectiveness of the phyto(co)remediation for wastewater decontamination by monitoring the growth, the bioaccumulation and removal of targeted toxicants from water in Lemna and Spirulina, for proposing their joint application for HM removal and organic pollutant degradation, and the use of biosurfactants for improving the phyto(co)remediation.
Young researchers (grant holders, research fellows etc.) will be involved in the project to acquire and improve expertise in planning of experimental design, analytical techniques, plant and algae cultivation, microscope technique, physiological performance evaluation, biometric data acquisition.
The project will represent the first stage for future collaboration in scientific consortia with other EU partners for Horizon 2020 joint proposals.

Research goals

The proposal aims at developing protocols to efficiently cultivate the macrophyte Lemna and the alga Spirulina in presence of different pollutants of the aquatic ecosystem as PPCPs, pesticides, HMs in laboratory trials. The protocols will define the basic conditions to assay the capability of such organisms to efficiently remove pollutants from water. In particular, the optimal conditions for absorption and utilization of the ecotoxicants as safe compounds by such biological organisms will be determined. The final goal is to create the biotechnological basis and to describe the potential of phyto(co)remediation technology as a prompt strategy of cleaning polluted water based on Spirulina and Lemna. Highly qualified expertise of the two research groups in cultivating and exposing biological organisms to pollutants will be shared giving added value to the investigation. Complementary techniques available in the two groups will be used in separate and common experiments to better define the potential of such organisms for phyto(co)remediation. Results of the project will contain novelty in both basic and applied scientific standpoints. As for the latter, the project will develop practical recommendations for governmental and non-governmental organizations involved in the environmental protection. Potential demanders of the project results are organizations dealing with the environmental technologies. The results will be also valuable for Spirulina and Lemna producing companies.

Last update: 06/08/2025