Studies on the influence of pharmaceutical and surfactant wastewaters on the physicochemical and geotechnical characteristics of fine grained soils

Abstract

Rapid industrialization has resulted in enormous generation of liquid and solid wastes and such wastes have been dumped on land either intentionally / unintentionally. Such actions in the past have resulted in the contamination of soil and / or ground water posing environmental problems and challenges to Civil Engineers, which calls for better understanding of the behaviour of such soil(s), so that they could be used for Civil Engineering / construction activities. It is well understood and established that inorganic and organic pollutants, in general, affect the various geotechnical characteristics of fine-grained soils. Comprehensive review of literature reveals that much work has not been carried out on the effect of industrial wastewaters on different types of fine-grained soils. However, such studies are important for understanding the interaction of pollutants in industrial wastewaters with soils and to take up appropriate action from a Geotechnical Engineering perspective. In view of the above, attempts have been made in this study to comprehensively investigate the effect of two wastewaters, namely, pharmaceutical wastewater (WW1) antibiotic based and containing organic suspended solids, in the form of mycelium fibres and a surfactant wastewater (WW2) in two types of locally available soils S1 (very high silt content and a very low clay content) and S2 (medium silt and clay content). Experimental investigations were carried out on a battery of single soilcolumnsfabricated using Perspex. Experiments were carried out under two modes of operation namely : (i) batch mode and (ii) continuous mode and at various hydraulic retention times (HRTs) and concentrations (8 h and 16 h ; 25% and 50%). Soils samples and wastewaters after passing through the soil-column were collected periodically and various parameters (pH, chloride, sulphate, COD etc.)