Exploring the potential of horse amendment for the remediation of HCHs-polluted soils.

This study assessed for the first time the bioremediation potential of an organic horse amendment in soils contaminated with solid wastes of the obsolete pesticide lindane (α-hexachlorocyclohexane (α-HCH) = 80 mg kg-1, ß-HCH = 40 mg kg-1, γ,δ,ε-HCH≈10 mg kg-1) searching for a self-sufficient bio-based economy. Four treatments were implemented: polluted (PS, ΣHCHs = 130 mg kg-1) and control (CS, ΣHCHs = 1.24 mg kg-1) soils and the respective amended soils (APS and ACS). A commercial amendment, coming from organic wastes, was used for soil biostimulation (5% dry weight), and the temporal evolution of the enzymatic activity (dehydrogenase, ß-glucosidase activity, phenoloxidase, arylamidase, phosphatase, and urease) and HCHs concentration of the soils was evaluated over 55 days under controlled humidity and temperature conditions. The horse amendment positively influenced the physicochemical properties of the soil by reducing pH (from 8.3 to 8) and increasing the organic matter (TOC from 0.5 to 3.3%) and nutrient content (P and NH4+ from 24.1 to 13.7 to 142.1 and 41.2 mg kg-1, respectively). Consequently, there was a notable enhancement in the soil biological activity, specifically in the enzymatic activity of dehydrogenase, phenol-oxidase, phosphatase, and urease and, therefore, in HCH degradation, which increased from <1 to 75% after the incubation period. According to the chlorine position on the cyclohexane ring, the following ranking has been found for HCHs degradation: ß-HCH (46%) < Îµ-HCH (57%) < α-HCH (91%) ≈ Î´-HCH (91%) < Î³-HCH (100%). Pentachlorocyclohexene (PCCH) and 1,2,4-trichlorobenzene (1,2,4-TCB) were identified as HCHs degradation metabolites and disappeared at the end of the incubation time. Although further research is required, these preliminary findings suggest that organic amendments represent a sustainable, harmless, and cost-effective biostimulation approach for remediating soils contaminated with recalcitrant HCHs, boosting the circular economy.

Estudio de los suelos de los alrededores del Balneario de Villavieja de Nules (Castellón de la Plana) / Study soil around the spa in Villavieja de Nules (Castellón de la Plana)

El suelo es la primera barrera natural que han de atravesar los compuestos depositados en la superficie terrestre para llegar a los acuíferos. Conocer las propiedades fisicoquímicas que intervienen en los procesos de infiltración, así como saber el tipo de suelo, son parámetros esenciales que nos permite analizar el riesgo de contaminación que afecta la composición del agua subterránea. En este trabajo se describen los factores ambientales de la zona, y se analizan algunas de las propiedades químicas, físicas y mineralógicas de cuatro suelos característicos de los alrededores del Balneario de Villavieja de Nules (Castellón de la Plana). Para ello se ha obtenido el contenido en: C, N, pH, CE, CIC y CO3 2‐ , así como se ha determinado: textura, densidad aparente, densidad real, porosidad, parámetros hidráulicos y la mineralogía de la fracción arcilla. De los resultados se desprende que las características ambientales de la zona, junto a los tipos de suelos analizados ralentizan los procesos de flujos descendentes (AU)

Soil i s the first natural barrier that has to be crossed by the compounds deposited on the Earth's surface to reach aquifers. Knowing about the physicochemical properties involved in the infiltration processes, as well as the soil type, are essential parameters which allows us to analyze the risk of contamination affecting the composition of groundwater. In this work, the environmental factors of the area around the Balneario de Villavieja Nules (Castellón de la Plana) are described, and some of the chemical, physical, and mineralogical characteristics of four soils are analyzed. Most particularly C, N, pH, CE, CIC y CO3 2‐ , as well as texture, bulk density, particle density, porosity, hydraulic parameters and clay fraction mineralogy were determined. The results showed that the environmental characteristics of the area, together with the types of soil analyzed slow down the water flow processes (AU)

Suelos del entorno del balneario / Soils in the thermal environment of "Villa de Olmedo" (Valladolid)

El conocimiento del suelo es imprescindible para comprender el riesgo de la posible afectación de las aguas subterráneas, especialmente en áreas sometidas a una fuerte presión de actividad agrícola. Se presenta el estudio de tres suelos localizados en los alrededores del Balneario "Villa de Olmedo", provincia de Valladolid. Se han desarrollado a partir de arcosas, situados en topografía llana, con una altitud entorno a los 750 m y bajo clima Mediterráneo templado. Se analizaron las propiedades morfológicas, físicas, químicas y mineralógicas de los suelos. En general, son suelos poco evolucionados, con textura gruesa, pH próximos a la neutralidad y horizontes superficiales con características ántricas

Soil characteristics are decisive in groundwater quality. The impact of human activities, especially in areas subject to agricultural pressure, involves potential risks which may be critical to the viability of the water resource. This work gathers together the study of three representative soils located in the thermal environment of "Villa Olmedo", Valladolid. All of them have developed from arkoses and found around 750 m elevation in a zone of flat topography. Morphological, physical, chemical and mineralogical properties of these soils were analyzed. They are poorly developed, coarse textured, with pH close to neutrality and antric features in the surface horizons

Estudio de los suelos del entorno del Balneario de San Nicolás (Almería) / Study soil in the thermal environment of San Nicolás (Almería)

Las propiedades fisico‐químicas de los suelos que se encuentran en la parte superficial de las capas freáticas, juegan un papel muy importante en las características hidroquímicas de las aguas subyacentes, pues fenómenos como disolución, hidrolisis y procesos de oxido‐reducción de fracciones minerales y orgánicas de los suelos influyen de forma significativa en la composición de las mismas. Además, textura, estructura y materia orgánica del suelo son factores claves en la regulación del régimen hidrodinámico. En este trabajo analizamos las características edáficas de cuatro suelos muy significativos de los alrededores del Balneario de San Nicolás, ubicado en Alhama de Almería, Alpujarra Almeriense, situada a 450 msnm en la ladera norte de la Sierra de Gádor. Son suelos con escaso desarrollo, tipo AC, formados a partir de materiales sedimentarios constituidos por margas arenosas, calcarenitas, dolomías y yeso, los situados en las proximidades del Valle del Andarax, y por materiales de derrubios de ladera y pie de monte, con predominio de cuarcita, dolomías, calizas y calizas margosas, los situados en la Sierra de Gádor. Los suelos son carbonatados y están saturados, siendo el calcio el catión mayoritario. Presentan pHs básicos, bajo contenido en materia orgánica y texturas gruesas. Cuarzo, calcita, dolomita y yeso son los minerales más abundantes entre los no laminares, y son las micas los filosilicatos presentes en mayor proporción. El predominio de texturas gruesas y la perdida de estructura en los horizontes profundos son determinantes en el grado de infiltración. Se han incluido en las unidades Regosoles y Calcisoles (AU)

The physico‐chemical properties of soils adjacent to aquifers play an essential role in the hydrochemical characteristics of the underlying waters. Thus, phenomena such as dissolution, hydrolysis and oxide‐reduction processes of the mineral and organic fractions of soils may have a significant influence on the composition of these waters. Furthermore, soil texture, structure and organic matter are key factors regulating the hydrodynamic regime. In this work, the edaphic characteristics of four highly representative soils located in the thermal environment of San Nicolas in the Alhama de Almería municipality of the Alpujarra Almeriense region were analyzed. The area is part of the northern side of the Sierra de Gádor at an altitude of 450 masl. They are poorly developed soils, mainly AC profiles. Soils in the vicinity of the Andarax Valley are formed on sedimentary materials constituted by sandy marls, calcarenites, dolomites and gypsum, and those in the Sierra de Gádor developed on debris material from hillside and piedmont and mainly integrated by quartzite, dolomites, limestones and marly limestones. Soils are carbonated and saturated, with calcium being the major cation. They have basic pH values, low organic matter content and coarse textures. Quartz, calcite, dolomite and gypsum are the prominent minerals among the non‐laminar ones, and micas among the phyllosilicates. The predominance of coarse textures and the loss of structure in the deep horizons are decisive in their infiltration capacity. They were classified as Regosols and Calcisols (AU)