groundwater

Environmental impact of a recent oil spill incident in Bonny terminal using soil media was studied using a risk-based modeling approach. The establishment of the presence of contaminants of concern (CoC), evaluation/assessment, modeling spilled volume and ascertaining potential health risk associated with the spill incident was carried out. The Contaminant of Concern (CoC) included Total Petroleum Hydrocarbons (TPH) and Polycyclic Aromatic Hydrocarbons (PAHs). Soils and groundwater were sampled in the vicinity of the spill incident and further away into the surrounding communities. Soils were sampled into the depths (0.1 m, 0.5 m,1.0 m, 1.5 m), and the results of sieve analysis revealed that the area is predominantly silty sand in composition. This study also revealed that TPH concentration at all locations and depths exceeded DPR target value of 50 mg/kg. The TPH model revealed that a total volume of 222,500m3 of the spill area exceeded DPR intervention value of 5000 mg/kg. The results of PAH showed that only BS-1, BS-6, BS-8, BS-9 and BS-10 exceeded DPR target value of 1.0 mg/kg at some depths. All other sample depths and locations were within the target limit. The 3-D grid generated for PAH showed that 563,000m3 of the study area exceeded the DPR target value. The 3-D block models generated for TPH and PAH, along with the cross-sections and extracted time slices all showed that the concentration of the Contaminant of Concern (CoC) generally decreased with depth, and the centre of the spill located at the south-eastern part of the survey area. Based on these models, three spill zones were identified; Zone 1-highly contaminated areas (BS-8, BS-9, BS-10); Zone 2 - moderately contaminated areas (BS-1, BS-2, BS-6, BS-7); and low contaminated areas (BS-3, BS-4, BS-5). The entire soil in the area were contaminated with TPH and 47% of the area contaminated with PAH. This study has shown the effectiveness of the use of a model-based approach in quantifying hydrocarbon contamination volumes in the area. There is therefore the need for continuous monitoring of hydrocarbon spills in the area.

The main focus of this study concentrates on evaluating the quality of groundwater in and around the zone of pattamadai where the production of the mat in this region is a landmark industry, which is using dyes in a larger volume. The primary work starts with the collection of water samples from 13 boreholes and 13 hand-dug wells in different time intervals in the month of March 2021, which is a dry season. As per standards the water quality parameters have been evaluated and observed to be within the range. All the physico-chemical parameters for the samples have been studied for boreholes and hand-dug wells as all the values are observed to be within the range and are highlighted in the results.

Compacted bentonite or sand-bentonite mixtures are considered buffer/backfill materials in the engineering barriers of deep geological repositories for high-level nuclear waste (HLW) disposal in many countries. The design and long-term functionality of nuclear repositories have critical importance for environmental safety and public health. The initially unsaturated buffer material could become re-saturated long after following the sealing of the repository. Although the saturation degree of the buffer might decrease due to high temperatures and evaporation, it tends to increase with groundwater intrusion. Therefore, the soil water characteristic curves (SWCCs) for these unsaturated soils are a key factor in geotechnical engineering. Yet, the determination of SWCCs can be time-consuming and prone to inaccuracies. The HYPROP (Hydraulic Property Analyzer) evaporation technique is a preferred method for accurately determining water retention curves of soils. This reliable method was applied to estimate the water retention curves for sand-bentonite mixtures in the presence of boron minerals. Known for their minimal thermal expansion and commonly used in various industries, boron minerals may improve the thermal stability of sand-bentonite mixtures. The findings revealed that the boron addition increased the water retention capacity of the 10% bentonite mixtures but had a negligible impact on the 20% bentonite mixtures.

Exposure to microplastics is unavoidable, and a vast amount of microplastics are traveling around the oceans. Microplastics are considered one of the major potential pollutants due to their exposure and interference with the health of humans, animals, aquatic species, agriculture, etc. Shockingly, the microplastic was also detected in the human placenta (fetal and amniochorial membranes), which could cause long-term effects on human health. The disposal of plastic into the oceans is the most happening process across the globe; thereby, microplastic pollution is evident, leading to a huge risk to marine species. Also, the accumulation of microplastics on soil or land leads to an increase in pH value, thereby affecting the surface water and soil-groundwater medium, eventually affecting plant and human health. At the same time, microplastics and their particles are found in milk, meat, and other edible items, which directly affects human health. The appearance of microplastic particles in insects, birds, animals, and even human blood indicates its adverse effect on the environment. This review has discussed the impact of microplastic on the health of humans, aquatic species, and agriculture.