Purpose

Degraded soils are unable to perform key functions and, thus, it is very important to develop effective reclamation methods. To restore utility or natural values to degraded ecosystems, various compounds are applied. In this study, the impacts of additives of various origin and composition on Polish (Eutric Cambisol) and Bulgarian (Epicalcic Chernozem) soils were compared. The main goal of the study was to make a comprehensive assessment of the validity of using popular soil additives in a real context.

Materials and methods

Physicochemical and hydrophysical parameters including pH, variable surface charge, porosity, specific surface area, wettability, sorption capacity relative to trace metals, and water retention of soils were taken into account. Surface charge and porosity of soils were determined using potentiometric titration and nitrogen adsorption/desorption method, respectively. Wettability was measured by sessile-drop method, whereas water retention, using different matric potentials (pF curves). Sorption study on trace metals included isotherm and kinetics determination as well as experimental data modeling.

Results and discussion

The most positive effect on soil surface charge, porosity, wettability, and cadmium (Cd) sorption was observed for synthetic zeolite, zeolite-carbon composite, and vermicompost. This effect was noted only for Polish soil characterized by poor porosity, low content of organic carbon, and moderately acidic reaction. For eroded Bulgarian soil, the condition of which was definitely better, the impact of modifiers was not spectacular. Among tested amendments, only divergan increased water retention properties of both examined soils significantly.

Conclusions

Zeolite, zeolite-carbon composite, and vermicompost can be apply for degraded soils of low organic carbon content, poor porosity, and moderately acidic pH to improve their physicochemical parameters and sorption ability toward trace metals. Divergan should be used to improve water retention of degraded soils during their reclamation.

中文翻译：

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退化土壤的复垦：有机/无机改性后选定参数的分析

目的

退化的土壤无法发挥关键功能，因此开发有效的复垦方法非常重要。为了恢复退化生态系统的效用或自然价值，使用了各种化合物。在这项研究中，比较了不同来源和成分的添加剂对波兰（Eutric Cambisol）和保加利亚（Epicalcic Chernozem）土壤的影响。该研究的主要目标是对在真实环境中使用流行土壤添加剂的有效性进行全面评估。

材料和方法

考虑了物理化学和水物理参数，包括pH值、可变表面电荷、孔隙率、比表面积、润湿性、相对于痕量金属的吸附能力以及土壤的保水性。分别采用电位滴定法和氮吸附/解吸法测定土壤的表面电荷和孔隙率。润湿性通过座滴法测量，而保水性则使用不同的基质电势（pF 曲线）测量。痕量金属的吸附研究包括等温线和动力学测定以及实验数据建模。

结果与讨论

合成沸石、沸石-碳复合材料和蚯蚓堆肥对土壤表面电荷、孔隙率、润湿性和镉 (Cd) 吸附具有最积极的影响。这种效应仅在波兰土壤中出现，其特征是孔隙率差、有机碳含量低、呈中等酸性反应。对于受到侵蚀的保加利亚土壤来说，其状况肯定更好，改良剂的影响并不引人注目。在测试的改良剂中，只有 divergan 显着提高了两种测试土壤的保水性能。

结论

沸石、沸石碳复合材料和蚯蚓堆肥可用于有机碳含量低、孔隙度差、pH值中等酸性的退化土壤，以改善其理化参数和对微量金属的吸附能力。Divergan 应用于改善退化土壤在复垦过程中的保水性。