Transformation of sulfaquinoxaline by chlorine and UV light in water: kinetics and by-product identification

Sulfaquinoxaline (SQX) is an antimicrobial of the sulfonamide class, frequently detected at low levels in drinking and surface water as organic micropollutant. The main goal of the present study is the evaluation of SQX reactivity during chlorination and UV irradiations which are two processes mainly used in water treatment plants. The SQX transformation by chlorination and UV lights (254 nm) was investigated in purified water at common conditions used for water disinfection (pH =?7.2, temperature =?25 °C, [chlorine] =?3 mg L^?1). The result shows a slow degradation of SQX during photolysis compared with chlorination process. Kinetic studies that fitted a fluence-based first-order kinetic model were used to determine the kinetic constants of SQX degradation; they were equal to 0.7?×?10^?4 and 0.7?×?10^?2 s^?1corresponding to the half time lives of 162 and 1.64 min during photolysis and chlorination, respectively. In the second step, seven by-products were generated during a chlorination and photo-transformation of SQX and identified using liquid chromatography with electrospray ionization and tandem mass spectrometry (MS-MS). SO₂ extrusion and direct decomposition were the common degradation pathway during photolysis and chlorination. Hydroxylation and isomerization were observed during photodegradation only while electrophilic substitution was observed during chlorination process.     

Spatio-temporal assessment and trend analysis of surface water salinity in the coastal region of Bangladesh

The study was designed to collect water samples over two seasons—wet-monsoon season (n = 96) (March–April) and dry-monsoon season (n = 44) (September–October)—to understand the seasonal variation in anion and cation hydrochemistry of the coastal rivers and estuaries contributing in the spatial trend in salinity. Hydrochemical examination of wet-monsoon season primarily revealed Ca–Mg–HCO₃ type (66%) and followed by Na–Cl type (17.70%) water. In the dry-monsoon season, the scenario reversed with primary water being Na–Cl type (52.27%) followed by Ca–Mg–HCO₃ type (31.81%). Analysis of Cl/Br molar ratio vs. Cl (mg/L) depicted sampling area affected by seawater intrusion (SWI). Spatial analysis by ordinary kriging method confirmed approximately 77% sample in the dry-monsoon, and 34% of the wet-monsoon season had shown SWI. The most saline-intruded areas in the wet-monsoon seasons were extreme south-west coastal zone of Bangladesh, lower Meghna River floodplain and Meghna estuarine floodplain and south-eastern part of Chittagong coastal plains containing the districts of Chittagong and Cox’s Bazar adjacent to Bay of Bengal. In addition, mid-south zone is also affected slightly in the dry-monsoon season. From the analyses of data, this study could further help to comprehend seasonal trends in the hydrochemistry and water quality of the coastal and estuarine rivers. In addition, it can help policy makers to obligate some important implications for the future initiatives taken for the management of land, water, fishery, agriculture and environment of coastal rivers and estuaries of Bangladesh.

     

Optimizing different adaptive strategies by using crop growth modeling under IPCC climate change scenarios for sustainable wheat production

Environment, Development and Sustainability - Crop production is highly sensitive to climate. It is affected by long-term trends in average rainfall and temperature, inter-annual climate...     

Optimal conditions to produce extracts of compost and vermicompost from oil palm and coffee pulp wastes

Journal of Material Cycles and Waste Management - Compost and vermicompost extracts represent an alternative to synthetic fertilizers and pesticides because of their beneficial effects on plants....     

Role of financial inclusion and export diversification in determining green growth: evidence from SAARC economies

This study quantifies the impact of financial inclusion and export diversification in attaining the target of green growth for SAARC economies during the period 2000 to 2019. For the analysis purpose, this study employed second-generation econometric techniques that deal with heterogeneity and cross-sectional dependence issues. To this end, CUP-FM and CUP-BC are used to investigate the long-run dynamic equilibrium relationship among the variables of interest. The outcomes show that financial inclusion and institutional quality are eco-friendly variables and play a vital role in attaining green growth. In contrast, export diversification and FDI are inversely related with green growth in SAARC economies. Furthermore, a unidirectional causality running from financial inclusion to green growth and financial inclusion to export diversification is observed. On the basis of investigated outcomes, this research suggests essential policy recommendations to attain green growth.

     

Occupational ocular health problems among marble workers at Shaq El Tho’ban industrial area in Egypt

Environmental Science and Pollution Research - Eye health of the working population is an essential condition for productivity. Marble industry is processed at large scale at Shaq El Tho’ban...     

The role of environmental transformational leadership in employees’ influencing organizational citizenship behavior for environment well-being: a survey data analysis

Environmental Science and Pollution Research - Many researchers and intellectuals focused on the topic of organizational citizenship behavior for the environment (OCBE); however, employees’...