Review of vadose zone soil solution sampling techniques

Abstract

Understanding the composition and fluxes of vadose zone soil water is extremely important to many environmental studies, and hence the monitoring of soil solution is of basic interest for different scientific and practical fields, including pedologic studies, water-use management, fate and transport of environmentally consequential pollutants, monitoring of disposal from mining and industries, nutrient management of agricultural and forest ecosystems, ecology, and environmental protection. Soil solution sampling techniques for effectively monitoring the quality and quantity of vadose zone soil pore water have been used to assess the persistence and transport of potential groundwater pollutants, assess the ecological and human health impact of such pollutants, and develope appropriate remediation strategies. However, there is still no consensus as to best techniques for soil solution collection at most field or laboratory soil conditions. The purpose of this review is to evaluate different laboratory and in-situ techniques of vadose zone soil solution sampling. This comprehensive review presents and discusses advantages and disadvantages of these techniques, problems and limitations of some of these techniques, proper installation, operation and pretreatment of samplers, interaction of pollutants with sampler materials, and proper selection of samplers under a wide range of potential pollutants measurements to provide a background and guidelines for the evaluation of recent developments.