• Título:  REHABILITATION OF CONTAMINATED SOILS AND WATER USING "TAILOR-MADE" TECHNOSOLS
• Autor:  Cerveira Fernandes, Maria João
• Universidad:  Universidad de Santiago de Compostela
• Departamento:  Escuela de Doctorado Internacional (EDIUS)
• Fecha de Lectura:  18/09/2023
• Programa de doctorado:  Programa de Doctorado en Ingeniería Química y Ambiental por la Universidad de Santiago de Compostela
• Dirección: 
  • Macías Vázquez, Felipe (DIRECTOR)
  • Fernandes Delerue Alvim de Matos, Cristina Maria (CODIRECTOR)
  • Lema Rodicio, Juan Manuel (TUTOR/PONENTE)
• Tribunal: 
  • ARIAS ESTEVEZ, MANUEL (PRESIDENTE)
  • OTERO PÉREZ, XOSÉ LUÍS (SECRETARIO)
  • Ferreira da Silva, Eduardo Anselmo  (VOCAL)
• Descriptores: 
  • CIENCIAS TECNOLOGICAS
  • INGENIERIA DE LA CONTAMINACION
• Localización:  BIBLIOTECA XERAL USC
• 724899_1641318.pdf
• Resumen:
  Environmental pollution, the disturbance of natural environmental processes that affect both the physical and biological components of the earth/atmosphere system, represents a serious and current problem for modern society. The substantial population growth has led to remarkable alterations in consumption patterns, including food and health necessities and consequent overuse of substances such as pesticides (food production) and pharmaceuticals (human and animal health). Both pharmaceuticals and pesticides are increasingly acknowledged as chemicals of emerging concern, with known negative impacts on soil and aquatic species and respective ecosystems and potential effects on human health. Fluoxetine is an anti-depressant pharmaceutical widely used to treat depression. As with other pharmaceuticals, only a part of this compound is metabolized by the human body, while the rest, as well as its metabolites, are excreted, eventually reaching the wastewater systems and potentially the environment. Glyphosate and glufosinate, two broad-spectrum, non-selective, organophosphorus herbicides, and aminomethylphosphonic acid (AMPA), the primary metabolite of glyphosate, are also three compounds of concern. The exposure level of humans and animals and the harmful effects of these compounds is largely documented. As well as other emerging pollutants, environmental contamination by fluoxetine, glyphosate, glufosinate, and AMPA, require corrective measures, imposing the development of remediation techniques for the rehabilitation of the affected areas. Several remediation technologies have been studied and developed to treat environmental contaminations. One of these remediation technologies is adsorption, a method in which molecules or particles of a substance are retained on the surface of a solid or liquid material through various mechanisms, such as electrostatic attraction, van der Waals forces, or chemical bonding. It is commonly used in industrial processes to remove impurities from liquids or gases, as well as in soil remediation, wastewater treatment, and drinking water purification. Also, it is a process that spontaneously occurs in many natural systems, such as in soil, benefiting the uptake of nutrients by plants or the adsorption of gases in the atmosphere by soil particles. Adsorption significantly affects the transfer and availability of pesticides in soil, being one of the main processes of controlling pesticide leaching and reducing their migration and the potential to contaminate surface waters or groundwater. As it is extensively used in large-scale wastewater treatments, due to its simple layout, high efficiency, and the possibility of using low-cost and non-toxic adsorbents, it can be optimized and applied to pharmaceutical and pesticide removal. To study the adsorption of different types of substances such as fluoxetine, glyphosate, AMPA, and glufosinate, evaluating the use of a wide variety of adsorbent materials and their physical-chemical properties is essential. Their selection is of great concern, and characteristics such as low cost, sustainability, non-toxic, and high sorption capacity are significant attributes to be considered. Biochar is a solid and stable porous material with high carbon content manufactured through pyrolysis/carbonization of biomass under a limited or absent oxygen environment and moderate temperature conditions. It is an attractive material to be implemented as an adsorbent to retain and remove pollutants from aqueous environments. Its use presents itself as a tool for environmental management, acting in soil improvement, waste treatment, climate change mitigation, and energy production. Besides being economically attractive, biochars are largely used as adsorbents due to their high retention capacity for distinct contaminants associated with their high specific surface and porosity, ion exchange capacity, and pH. The feedstock selection can largely influence its properties, as well as the production process conditions, namely temperature range, heating rate, pressure, and residence time. Another innovative remediation technology is the use of tailor-made Technosols. Technosols are a reference soil group defined in the World reference base for soil resources (by the Food and Agriculture Organization of the United Nations and International Union of Soil Sciences) as a combination of soils "whose properties and pedogenesis are dominated by their technical origin". Significantly dominated or strongly influenced by human-made, strongly altered material (referred to as artifacts such as waste materials namely bricks, glass, household waste, mine waste, sludge, etc.) or extracted from greater depths, these soils are frequently found in urban and industrial areas. Tailor-made Technosols (TMTs) are engineered soils created by the combination of natural soil with anthropogenic materials derived from human activities with other additives to obtain the desired characteristics. They replicate functions of natural soil and can be used to provide several soil functions and ecosystem services, such as suitable conditions for plant growth/production (food and biomass), soil remediation, carbon sequestration, restoring water bodies and degraded or polluted areas, groundwater recharge, and ecosystem biodiversity. Biochar is one of the materials that can be incorporated into the production of tailor-made Technosols. Thus, as a first approach to the problems addressed in this work, monitoring antibiotics and anti-depressants in the waters and sediments along two rivers in northern Portugal was carried out. Sediment samples were collected from two layers, the top layer, within 0 and 2 cm depth, and bottom layer within 2 and 10 cm. The present study involved the characterization and analysis of samples for seventeen antibiotics and ten antidepressants. A comparison of pharmaceutical concentrations in samples from the Leça River and the Douro River revealed higher levels in the Leça River. Only carbamazepine and fluoxetine were detected in the Douro water samples, whereas the Leça water samples contained thirteen out of twenty-seven pharmaceuticals, including six antibiotics and seven psychiatric drugs. Notably, azithromycin was found at the highest concentration (2.82 µg/L) in the Leça River samples, particularly near a wastewater treatment plant effluent discharge point. Fluoxetine exhibited the highest detection frequency in water samples. The presence of carbamazepine and venlafaxine in Leça River water indicated potential risks to algae. In sediment samples, sulfamethoxypyridazine was found in Douro sediment, while azithromycin was detected in Leça sediment, both primarily in the top sediment layer. Psychiatric drugs were also detected, with four found in Douro sediment and six in Leça sediment. A comparison between the top and bottom sediment layers at each sampling point showed that venlafaxine, the only quantified pharmaceutical in the Douro River, exhibited a higher concentration in the bottom zone, potentially related to soil migration. In Leça sediments, higher concentrations were observed in the top layer, likely associated with recent pollution events in the area. A review of monitoring studies reported in the literature revealed a reduced inclusion of sediment analysis, with most studies focusing solely on water samples (especially for psychiatric drugs). Therefore, it was not possible to identify a consistent contamination pattern or establish a clear link between sediment contamination and the migration of contaminants from water, based on the obtained results and literature comparisons. However, higher concentrations of contaminants were consistently observed at sampling locations downstream of wastewater treatment plant discharges. Additionally, a literature review of glyphosate, AMPA, and glufosinate contamination of water and sediment worldwide was performed. The aim was to investigate the contamination and mobility of the referred substances in aquatic environments, with a specific focus on water and sediment samples. The research included a comprehensive literature search to analyze studies published within the last five years that monitored the concentrations of these compounds in water (both surface and groundwater) and sediments. The analysis of applicable legislation revealed significant variations in limit values for these pollutants across different countries. For instance, European Union set the lowest legal limit for glyphosate residues in water intended for human consumption, with a threshold of 0.1 µg/L, while Japan established the highest limit at 2 000 µg/L. The most commonly used detection methods in the analyzed studies were high-performance liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). However, it was found that only 40% of the reviewed studies reported detection limits below the European Union's maximum permissible value for individual pesticide water contamination (0.1 µg/L). The investigation of glyphosate monitoring in water and sediments revealed interesting trends. France emerged as the country with the highest samples/publication ratio, followed by Japan and Italy. Argentina, on the other hand, had a higher frequency of study publications but a lower samples/publication ratio. Notably, the European countries that conducted a higher number of glyphosate level analyses tended to correspond with an increased rate of glyphosate application. As for AMPA monitoring, Argentina had a higher frequency of studies, while France maintained its position as the country with the highest samples/publication ratio, followed by the USA, Sweden, and Italy. China stood out with a significantly larger number of samples monitored for glufosinate compared to other countries with publications on this compound. Maximum contaminant concentrations varied depending on the environmental matrix. In surface water, the highest concentrations were found for AMPA (6 872 µg/L), followed by glyphosate (5 750 µg/L) and glufosinate (13.15 µg/L). In groundwater, the maximum values were 8 700 µg/L for glyphosate, 233 µg/L for AMPA, and 0.03 µg/L for glufosinate. Sediments displayed the highest detected concentrations of glufosinate (14.9 µg/kg), while glyphosate and AMPA reached maximum concentrations of 1 882 µg/kg and 4 033 µg/kg, respectively. Contrary to expectations, the maximum glyphosate concentration was higher in groundwater than in surface water. However, the frequency of detection was significantly higher in surface water (70%) compared to groundwater (18%). As for AMPA and glufosinate, the detection frequency in surface water was 87% and 6%, respectively, while in groundwater, it was 16% and 0.7%. South American countries presented the highest values of maximum detected concentration for glyphosate and AMPA, while sediments were the environmental matrix with the highest concentration of glufosinate. France had the highest maximum concentrations of glyphosate in surface waters, followed by Italy and Germany. In groundwater, Sweden exhibited the highest glyphosate concentrations, followed by Italy. Germany and Croatia presented the maximum concentration levels in sediments. Several factors were identified as drivers for the dispersion of these compounds in surface water, sediments, and groundwater. These factors included overspray, spray drift, surface run-off, shallow water tables, low hydraulic conductivity in aquifers, low hydraulic gradient, very low flow velocity, soil type, and chemical constitution. The persistent and escalating application of these compounds in agricultural and domestic activities, improper use, and wastewater treatment plants were identified as potential sources of contamination. This review shed light on the contamination and mobility of glyphosate, AMPA, and glufosinate in water and sediments. The findings emphasized the need for ongoing monitoring efforts and for the development of remediation strategies to mitigate the environmental impact of these compounds. The results also highlighted the importance of harmonized legislation and unified limit values across countries to ensure effective protection of water resources. In light of the documented contamination associated with the compounds under investigation, it is crucial to identify remediation technologies that not only address contaminated sites but also reduce the mobility of these compounds. Such technologies can prevent water and soil contamination and minimize the associated health problems resulting from the ingestion of these compounds. Consequently, this research focused on studying the adsorption of fluoxetine, glyphosate, AMPA, and glufosinate onto various materials, with different characteristics, in order to understand and optimize their adsorption. To this end, adsorption studies, namely equilibria, kinetics, and pH influence assays, were developed to study the adsorption of the four compounds under analysis. Different adsorbents with distinct characteristics were tested to find the most suitable materials and characteristics to integrate the composition of a tailor-made Technosol. If applied to a tailor-made Technosol production, the results will allow the development of an innovative and integrated solution that contributes to improving the quality of natural resources, sustainability, reducing waste production, and restoring contaminated areas. The first phase of the study involved testing twelve biochars derived from different forest and agri-food wastes (pruning of Quercus ilex, Eucalyptus grandis, Pinus pinaster, Quercus suber, Malus pumila, Prunus spinosa, Cydonia oblonga, Eriobotrya japonica, Juglans regia, Actinidia deliciosa, Citrus sinensis and Vitis vinifera) as potential low-cost and renewable adsorbents for fluoxetine removal from water. Preliminary adsorption experiments allowed to select the most promising adsorbents, Quercus ilex (hollow tree), Cydonia oblonga (quince), Eucalyptus, Juglans regia (walnut tree) and Vitis vinifera (vine) pruning material. They were characterized by proximate, elemental and mineral analysis, thermogravimetric analysis, Fourier transform infrared spectroscopy, determination of specific surface area and pH at the point of zero charge (pHPZC). Batch and equilibrium studies were performed, and the influence of pH was evaluated. The adsorption capacities of the selected biochars were determined, with values ranging from 2.21 to 6.41 mg/g according to the Langmuir model. Among the biochars tested, eucalyptus biochar exhibited the highest adsorption capacity, followed by hollow tree, vine, walnut tree, and quince biochars. The adsorption kinetics were rapid, with complete adsorption occurring in less than 15 minutes. Column adsorption experiments conducted with eucalyptus biochar demonstrated its effectiveness in continuous mode, presenting a breakthrough for 50% removal at 90 minutes, suggesting its potential as a renewable alternative for fluoxetine removal. The following phase of the research focused on investigating the adsorption of glyphosate, AMPA, and glufosinate onto forty-one different materials, including biochars, soils, and tailor-made Technosols (TMTs). Tested biochars were produced from acacia (Acacia melanoxylon) trunk divided in sapwood (BAcSw-3) and heartwood (BAcHw-2), eucalyptus branches (BEu-2), pine sawdust (BSd-1), pine bark (BPb), olive pomace compost (BOpc), rice husk (BRh), corncob (BCc1 and BCc-2), and German crushed wood chips (BSdG). The eight tested soil samples were Aluminic Umbrisols (S4A, 11B, 13A), Ferrasols derived from amphibolites (S9B), Háplic Umbrisols (1Ah and 2Ah) and Andic and Ferralic Leptosols (referred as Andic and Ferralic). Relatively to TMT, the tested materials were classified as Arenic Calcic Technosol (TMT 1), Aluandic Technosol (TMT 2), Andic Eutric Technosol (TMT 3, G, I, J, K, L, M, Q, R and S), Reductic Eutric Technosol (TMT 4 and A), Dystric Technosol (TMT B and D), Calcic Technosol (TMT C), Andic Technosol (TMT E and F), Eutric Technosol (TMT H and O), Ferric Technosol (TMT N) and Reductic Andic Technosol (TMT P). These TMTs were produced from industrial and agro-industrial waste, namely mine sediment, sawdust biomass, sludge from wastewater treatment, organic compost, ash, and sand. The results indicated that the three compounds were poorly adsorbed by most of the biochar samples, with maximum removal rates of 25% for glyphosate, 12% for AMPA, and 4% for glufosinate. These results were primarily attributed to the production temperature of the biochars. In contrast, the tested soils exhibited high adsorption capacities for glyphosate and AMPA, with maximum removal rates of 94% and 91% in the preliminary assays, respectively. However, the adsorption of glufosinate was limited, with removal rates not exceeding 6%. The TMTs also showed significant adsorption capacities during preliminary assays, with maximum removal rates of 79% for glyphosate and 83% for AMPA. Once again, glufosinate exhibited low adsorption values, with a maximum removal rate of only 3%. Additionally, smaller grain sizes were found to enhance adsorption performance compared to soils or TMTs with larger grain sizes. The equilibrium time for adsorption varied, with total adsorption occurring in 14 hours for soils and 72 hours for TMTs, which is consistent with previous findings in the literature. The maximum adsorption capacities, according to the Langmuir model, were determined to be 10.84 mg/g for glyphosate (soil S9B) and 15.08 mg/g for AMPA (TMT 1). In terms of pH influence on the adsorption process, glyphosate and aminomethylphosphonic acid (AMPA) exhibit distinct charge behaviors. Analyzing de pH impact in the adsorption process with the tested adsorbents, which have a pHPZC of approximately 4.9, the adsorption of glyphosate and AMPA exhibited pH-dependent behavior. The adsorption increased between pH 1 and pH 3, corresponding to the protons loss associated with the carboxyl group of glyphosate (pKa2) and the phosphonic group of AMPA (pKa1) in the presence of a predominantly positively charged adsorbent surface. Subsequently, there was a gradual decrease in adsorption between pH 3 and pH 6, more pronounced for glyphosate than for AMPA. Between pH 6 and 10, the adsorption of glyphosate onto the tested adsorbents significantly decreased, except for TMT 1, which only exhibited reduced adsorption at pH higher than 10, approaching values close to zero. In the case of AMPA, the reduction in adsorption by TMTs occurred more prominently from pH values higher than 9, with relatively constant adsorption observed between pH 6 and 10 for the other adsorbents. For all adsorbents, there was a notable decrease in adsorption to values close to zero between pH 10 and 12, except for glyphosate adsorption onto soil S4A, which exhibited slightly higher adsorption at pH 12 compared to the other adsorbents. Overall, higher adsorption of glyphosate and AMPA onto soils and TMTs occurred within the pH range of 2 to 5, with the adsorbents surfaces predominantly positively charged, and although the main ionic form of AMPA within this pH range is neutral. These findings demonstrate that natural soils and TMTs can serve as effective, low-cost, and sustainable adsorbents for removing glyphosate and AMPA from aqueous solutions. Moreover, materials with relatively low pH and high aluminum and iron oxides, clay content, and organic matter should be selected for TMT production. The development of tailor-made Technosols offers an innovative and integrated solution that contributes to improving the quality of natural resources, promoting sustainability, reducing waste production, and restoring contaminated areas. Overall, the knowledge acquired leads to a better understanding of the current state of environmental contamination by pharmaceuticals and pesticides, showing that pollution not only reaches the watercourses but also sediments and groundwater are affected. This research provides valuable insights into the adsorption of fluoxetine, glyphosate, AMPA, and glufosinate onto different materials. The adsorption studies showed, among other results, that the tested biochar materials stood as excellent adsorbent materials of fluoxetine but, on the contrary, do not present a good retention capacity to compounds such as glyphosate, AMPA, and especially glufosinate. On the other hand, soils and Technosols have shown a high retention capacity for glyphosate and AMPA. Glufosinate did not tend to adsorb to any of the tested materials. The findings support the development of remediation technologies aimed at mitigating the environmental impact of these compounds, preventing contamination, and safeguarding public health. Additionally, propose the use of biochar as components of Technosols produced to retain fluoxetine. It also highlights some of the key characteristics required from the Technosol constituents for adequate adsorption of glyphosate and AMPA.