While numerous studies have examined pollution sources and seasonal effects on surface water quality independently, the complex interactions between these factors remain understudied. This research aimed to fractionate and quantify pollution sources and examine their interactive effects with seasonal variations on surface water quality in Khanh Hoa, Vietnam. The current study was based on 1080 surface water samples taken from three common water bodies - lakes, rivers, and canals across dry and rainy seasons and analyzed for 13 physiochemical properties. Findings revealed that surface water quality was influenced by four primary pollution sources: agricultural activities, residential areas, onsite erosion, and climatic factors. Agricultural sources dominated canal water quality (93.0-94.7%) but had less impact on lakes and rivers (12.8-23.8%). Residential sources significantly affected lakes and rivers (30.23-32.66%) but minimally influenced canals (2.6-5.6%). Onsite erosion sources had greater impacts on lakes and rivers typically during the rainy season and exhibited minimal impacts on canals. Lakes and rivers maintained consistent and higher water quality across seasons (water quality index (WQI) 9.1 to 9.3 out of 1.0 - excellent), while canals exhibited substantially lower quality in the dry season (WQI 0.75) compared to the rainy season (WQI 0.78). These interactive impacts were mitigated by self-purification, water residence time in lakes and rivers, dilution effects, and fast pollutant transport in canals. Our findings highlight the importance of effective management of these key pollution sources in interaction with seasonal variation for maintaining water quality and ensuring environmental sustainability.

Using tapes in drip irrigation is associated with environmental problems due to the accumulation of tapes in agricultural areas. Farmers either leave them on the fields or burn them or bury them. All three of these methods pose dangerous environmental hazards. To address this issue, it is recommended that these materials be produced from or with biodegradable materials. In this study, a biodegradable additive was used as a degradation accelerator in the production of tapes. After the production of these tapes, they were used under real conditions and during a growing season and in two treatments: below and on the soil surface, along with a canopy and without shade (beans and radishes). After 6 and 11 months, the tapes were sampled to investigate their degradation. The results showed that tapes made with oxo as an additive began to degrade more quickly than did conventional tapes. A reduction in properties such as weight (p 0.05), Young's modulus (p < 0.05) and toughness (p < 0.05) in tapes produced with oxo additives shows more and faster degradation than conventional tapes. Therefore, the use of oxo master batches in the production of tapes is possible and useful.

The Tibetan Plateau is the Asia Water Tower and is pivotal for Asia and the whole world. Groundwater is essential for sustainable development in its alpine regions, yet its chemical quality increasingly limits its usability. The present research examines the hydrochemical characteristics and origins of phreatic groundwater in alpine irrigation areas. The study probes the chemical signatures, quality, and regulatory mechanisms of phreatic groundwater in a representative alpine irrigation area of the Tibetan Plateau. The findings indicate that the phreatic groundwater maintains a slightly alkaline and fresh status, with pH values ranging from 7.07 to 8.06 and Total Dissolved Solids (TDS) between 300.25 and 638.38 mg/L. The hydrochemical composition of phreatic groundwater is mainly HCO3-Ca type, with a minority of HCO3-NaCa types, closely mirroring the profile of river water. Nitrogen contaminants, including NO3-, NO2-, and NH4+, exhibit considerable concentration fluctuations within the phreatic aquifer. Approximately 9.09% of the sampled groundwaters exceed the NO2- threshold of 0.02 mg/L, and 28.57% surpass the NH4+ limit of 0.2 mg/L for potable water standards. All sampled groundwaters are below the permissible limit of NO3- (50 mg/L). Phreatic groundwater exhibits relatively good potability, as assessed by the entropy-weighted water quality index (EWQI), with 95.24% of groundwaters having an EWQI value below 100. However, the potential health risks associated with elevated NO3- levels, rather than NO2- and NH4+, merit attention when such water is consumed by minors at certain sporadic sampling locations. Phreatic groundwater does not present sodium hazards or soil permeability damage, yet salinity hazards require attention. The hydrochemical makeup of phreatic groundwater is primarily dictated by rock-water interactions, such as silicate weathering and cation exchange reactions, with occasional influences from the dissolution of evaporites and carbonates, as well as reverse cation-exchange processes. While agricultural activities have not caused a notable rise in salinity, they are the main contributors to nitrogen pollution in the study area's phreatic groundwater. Agricultural-derived nitrogen pollutants require vigilant monitoring to avert extensive deterioration of groundwater quality and to ensure the sustainable management of groundwater resources in alpine areas.