Vol.:(0123456789) 1 3 Innovative Infrastructure Solutions (2020) 5:95 https://doi.org/10.1007/s41062-020-00342-7 STATE-OF-THE-ART PAPER Possible efects and reactions between leachate and diferent clay material types I. A. Oyediran 1  · D. A. Olalusi 1  · M. T. Jimoh 2 Received: 18 April 2020 / Accepted: 14 July 2020 © Springer Nature Switzerland AG 2020 Abstract Interactions between landfll leachate and some clayey soils were investigated to elucidate their possible efects and reactions and the extent to which the chemical composition of landfll leachate infuences the chemical and mineralogical properties of the soils upon leachate contact. Physicochemical properties of landfll leachate was obtained while the clay mineralogy, major and minor oxides composition, pH, cation exchange capacity (CEC), carbonate content and total organic carbon of Shale (Sedimentary), Migmatite gneiss and Quartzite (Basement Complex)-derived clayey soils after three-weeks saturation with leachate were determined. Dark brown colour and malodorous smell of landfll leachate is linked to high concentration of dissolved organic substances in the leachate composition while high leachate pH indicates an old and stabilized leachate with its temperature impacting the bacterial growth and chemical reaction. Signifcant changes were observed in both chem- istry and mineralogy of the clays after leachate contact with observed appearance of Illite in the migmatite gneiss-derived clayey soil, an indication of mineralogical changes caused by ionic solutions. Enrichment of Ca, SiO 2 and Cl; in addition to increased CEC for all the soils is generally noticed. Furthermore, leachate contact resulted in modifcation of Basement Complex-derived soils from acidic to alkaline soils while the sedimentary terrain-derived soils retained its alkaline pH nature. Hence, alteration in mineralogical and chemical properties observed in the diferent derived clayey soils is a func- tion of the leachate composition, sorptive capacity of the soils, parent material and especially the inherent reactions upon leachate contact. Keywords Reactions · Landfll leachate · Alteration · Signifcant changes Introduction Landfll leachate formed from urban solid waste is com- monly contaminated and contains multifaceted wastewater [1, 2]. The generation of leachate is as a result of percola- tion of precipitation via open landfll coupled by means of any disposed liquid wastes, which results in the withdrawal of water soluble compounds and particulate material of the wastes [3]. The distinctiveness of leachate are greatly unpre- dictable depending on the waste composition, amount of pre- cipitation, site hydrology, waste compaction, cover design, sampling procedures and leachate—soil interaction, others are landfll design and operation [4, 5]. Clay soils have over the years become the preferred barrier and liner material commonly used in engineered waste disposal systems in order to curtail leachate movement and protect the underly- ing soils and aquifers. Rowe et al. [6] and Rowe [7] opined that these natural materials have become the veritable option for use particularly because of their availability, low cost for a relative thick lining, long life and attenuating ability. However, the reactions, which take place between these most preferred barrier option (clayey soils) and natural leachate as opposed to synthetic leachate (or in some cases water) have not been well documented. In addition, data on the responses of the diferent clay soils which possess diverse mineralogical composition and chemistry particularly as it relates to soil properties and associated reactions is scanty. More importantly, an examination of the compatibility of the clays with waste leachate is required since Shackelford and Jeferis [8] stipulated that one of the fundamental design * I. A. Oyediran oyediranibrahim2012@gmail.com; oyediranibrahim@yahoo.com 1 Department of Geology, Faculty of Science, University of Ibadan, Ibadan, Nigeria 2 Department of Earth Science, Ladoke Akintola University of Technology, Ogbomoso, Nigeria