Microplastics (MPs) have been identified as an emerging soil pollutant and a global environmental concern. Scientists have recently paid attention to the contamination of soil by MPs as their detrimental impacts on soil systems are largely unknown. MPs are considered to be vectors for other soil contaminants, such as potentially toxic elements (PTEs) and organic contaminants. PTEs are persistent contaminants and are often released into soils in large quantities. MPs adsorb PTEs, mainly via electrostatic attraction and surface complexation, and increase their mobility in soils. These complexes can be easily absorbed by plants; hence, the accumulation of PTEs in plants can be enhanced in both microplastic and PTE contaminated soils. Furthermore, there is a high risk of food chains contamination by PTEs due to crops grown in both microplastic and PTE-contaminated soils. Consequently, countermeasures including policy- and governance-based approaches that target circular economy as well as reduce, reuse, recycle (3R) applications are being discussed around the world to minimize the environmental contamination of MPs.
Waterborne diseases are a global problem that causes more than 2.2 million deaths annually. Therefore, the present study was focused on microbiological contamination of both ground and surface water by means of total coliform, Escherichia coli (E. coli), Salmonella spp., Shigella spp. and Campylobacter spp. Seventy two groundwater and 45 surface water sampling locations were selected to collect water from the head, transitional and meandering regions of the Kelani River Basin for a period of one year (both dry and wet seasons). The results of the study revealed that the entire Kelani River basin was contaminated with total coliform and E. coli bacteria and almost all the sampling locations exceed Sri Lanka Standards Institute (SLSI) guideline value given for drinking water (0 CFU/100 mL). Further, in groundwater, 17 locations were positive for Salmonella spp., whereas only 2 locations were positive for Campylobacter spp. In surface water, 26 and three sampling locations were positive for Salmonella spp. and Campylobacter spp., respectively. In this study, 23 different human pathogenic serovars were isolated and the Salmonella enterica serovar Kentucky was identified as the commonest type. Thus, the result of the study revealed that the consumption of raw water from the Kelani River Basin is unsafe and possible to cause gastrointestinal diseases.
In the Sri Lankan context, the lack of baseline studies to mitigate microplastic emissions through personal care and cosmetic products poses a huge problem. Hence this study serves as the first scientific investigation to analyze and characterize microplastics in selected personal care and cosmetic items available in the Sri Lankan markets. Fifteen brands representing five categories (face wash, facial scrubs, baby creams, shaving creams, and skin creams) of personal care and cosmetic items served as the basis for this investigation. Based on a questionnaire survey, from each category, three highly utilized brands were chosen and triplicates from each brand were used for the analysis. All samples were treated with the Fenton reagent to extract microplastics. Then through Nile red staining suspected microplastic were screened and characterized through FT-IR spectroscopy. The Nile Red analysis revealed seven brands of the fifteen to be stained with Nile Red and demonstrate luminance properties under UV light. However, FT-IR analysis proved only six brands contained actual microplastics. Low-density polyethylene and ethylene-propylene copolymer were the dominant types of microplastic. Most microplastics were irregularly shaped and white in color with sizes ranging from 238.55 ± 50.74 to 450.69 ± 174.9 μm. An emission estimation revealed that products FS-01 and FW-03 contain 3.36 ± 0.20 g and 0.2 ± 0.05 g of isolatable microplastics per product. While the present study provides scientific evidence for the availability of microplastics in products in Sri Lankan markets, it also provides a great opportunity to develop relevant policies and regulations to control them.
1 March 2019 in Journal of Water and Land Development
In Sri Lanka, among 2588 Salmonella positive cases, the highest incidences were recorded from Jaffna peninsula during 2005 to 2013. Therefore, the present study aimed to identify the microbiological and chemical contamination status of groundwater (40 well water) sources in Jaffna during November 2016. The total coliform, E. coli, Salmonella spp. and Shigella spp. along with some physico-chemical parameters of groundwater were studied. The results revealed that entire peninsula was contaminated with total coliform and E. coli bacteria and the parameters recorded were not within the WHO and SLS (Sri Lanka Standards) drinking water quality standards. 38% of sampling locations were positive for Salmonella spp. and among them six sampling locations were being used for drinking purposes. The results of the study correlates with the statistics of typhoid cases recorded in Jaffna. Results of the study also revealed that around 80% of wells were not within the values specified in guidelines of the SLS for drinking water quality on electrical conductivity. Further, 15% of wells recorded greater than 10 mgꞏdm–3 nitrate, which is still below the SLS drinking water standards (45 mgꞏdm–3). According to the water quality data, PCA analysis showed that Jaffna town, Nallur, Tellippalai and Kopay DS divisions has similar characteristics for water quality.
Synthetic fibers are widely used in daily life due to their durability, elasticity, low cost, and ease of use. The textile industry is the primary source of synthetic microfibers, as these materials are mostly used in production processes. Globally, plastic pollution has been identified as a major environmental threat in this era, since plastics are not degradable but break down into smaller particles such as mesoplastics, microplastics, and microfibers. Synthetic microfiber pollution is a significant issue in aquatic ecosystems, including oceans and rivers, with laundry wastewater being a major source. This problem is particularly pressing in cities like Galle, Sri Lanka, where numerous tourist hotels are located. Despite the urgency, there has been a lack of scientific and systematic analysis to fully understand the extent of the issue. This study addresses this gap by analyzing the generation of microfibers from laundry activities at a selected hotel and evaluating the efficiency of a laundry wastewater filtration system. This study focused on a fully automatic front-loading washing machine (23 kg capacity) with a load of 12 kg of polyester–cotton blend serviettes (black and red). Samples (1 L each) were taken from both treated and untreated wastewater during four wash cycles, with a total of 100 L of water used for the process. The samples were filtered through a 100 μm sieve and catalytic wet oxidation along with density separation were employed to extract the microfibers, which were then collected on a membrane filter paper (0.45 μm). Microfibers were observed and analyzed for shapes, colors and sizes under a stereo microscope. Results revealed that untreated laundry wastewater contained 10,028.7 ± 1420.8 microfibers per liter (n = 4), while treated wastewater samples recorded 191.5 ± 109.4 microfibers per liter (n = 4). Most of the microfibers observed were black and white/transparent colors. Further analysis revealed that 1 kg of polyester–cotton blend fabric can generate 336,833 microfibers per wash, which was reduced to 6367 microfibers after treatment. The filtration unit recorded an impressive efficiency of 98.09%, indicating a remarkably high capacity for removing microfibers from wastewater. These findings highlight the potential of such filtration techniques to significantly reduce microfiber emissions from laundry wastewater, presenting a promising approach to mitigating environmental pollution from microfibers.
1 September 2019 in Journal of Water and Land Development
Typhoid or enteric fever is a worldwide infection caused by the bacterium Salmonella enterica. In Sri Lanka, 12,823 Salmonella positive cases were recorded and 133 cases were recorded from Anuradhapura district during 2005 to 2014. Therefore, the study was carried out to identify the microbiological and chemical contamination status of forty-four water sources in Anuradhapura area during October 2016. The study was focused to determine total coliform, faecal coliform, Salmonella spp. and Shigella spp. contamination along with some physico-chemical parameters of both ground and surface water. Sampling, transportation, and analysis were performed following standard protocols. Results of the study revealed that almost all sampling locations were contaminated with both total and E. coli bacteria and the values were not within the World Health Organization and Sri Lanka Standards drinking water quality standards. Around 32% of sampling locations were positive for Salmonella spp. and among them, 2 spring sampling locations are being highly used to extract water for drinking. However, Shigella spp. was not recorded during the study period. Majority of the sampling points were not within the Sri Lanka drinking water standards for COD and 25% sampling locations were recorded greater than 750 μS∙cm−1 conductivity. Also, 55% of locations recorded very hard water where the highest values were recorded in Padaviya. The tested other water quality parameters: NO2-N, NH3-N, and total phosphate (TP) concentrations were found within the Sri Lanka drinking water standards. PCA analysis revealed that sampling locations were grouped into three groups such as; well water, tank water and springs.