Effects of environmental factors on the seasonally change of phytoplankton populations in a closed freshwater pond.

The effect of environmental factors affecting the population dynamic of phytoplankton population was studied seasonally in a closed freshwater pond with the natural water of Lake Kasumigaura, Japan. The predominant phytoplankton species in the pond were classified as Oscillatoria tenuis, Synedra ulna, Chlamydomonas cingulata and Cyclotella kutzingiana, with dominant species of Melosira italica, Synechococcus sp. and Cryptomonas ovata. The most important limiting factor for filament length and cell size of most of the phytoplankton community was temperature. Availability of most nutrients had profound effects on the phytoplankton growth as nonlimiting factors. Based on our results, it is suggested that cell cycle progression was also temporally regulated by a multiplicity of external factors such as temperature, nutrients, dissolved oxygen (DO) and pH. At high pH and high temperature, consistent increase of cell division of some phytoplanketers such as Synedra, Cyclotella, Chlamydomonas and Melosira occurs, and there also may be species-specific responses for other species of phytoplankters. In addition, the cell divisions of phytoplankters are differentially regulated in different phytoplankton species.     

A critical review of the emerging research on the detection and assessment of microplastics pollution in the coastal,marine, and urban Bangladesh

● Coastal and marine regions are the most studied for microplastic pollution. ● Tourism is a major cause of microplastic pollution in coastal regions. ● Sediments contain larger microplastics while fish ingest smaller microplastics. ● Inland lakes, rivers, and freshwater fish are impacted by microplastic pollution. ● Microplastics are found in edible salts, however, presence is less in refined salt. The research on the extent and effects of microplastics pollution in the Global South is only getting started. Bangladesh is a South Asian country with one of the fastest growing economies in the world, however, such exponential economic growth has also increased the pollution threats to its natural and urban environment. In this paper, we reviewed the recent primary research on the assessment of the extent of microplastics pollution in Bangladesh. From the online databases, we developed a compilation of emerging research articles that detected and quantified microplastics in different coastal, marine, and urban environments in Bangladesh. Most of the studies focused on the coastal environment (e.g., beach sediment) and marine fish, while limited data were available for the urban environment. We also discussed the relationship of the type of anthropogenic activities with the observed microplastic pollution. The Cox’s Bazar sea beach in south-east Bangladesh experienced microplastics pollution due to tourism activities, while fishing and other anthropogenic activities led to microplastics pollution in the Bay of Bengal. While microplastics larger than 1 mm were prevalent in the beach sediments, smaller microplastics with size below 0.5 mm were prevalent in marine fish samples. Moreover, the differences in microplastic abundance, size, shape, color, and polymer type found were depended on the sampling sites and relevant anthropogenic activities. It is imperative to identify major sources of microplastics pollution in both natural and urban environment, determine potential environmental and human health effects, and develop mitigating and prevention strategies for reducing microplastics pollution.     

Effect of chromium on growth attributes in sunflower (Helianthus annuus L.)

Heavy metal soil pollution takes place when the metal concentration of soil exceeds natural background level and causes ecological destruction and deterioration of the environment.In the present study,a pot experiment was conducted to evaluate the effect of chromium-contaminated soil in sunflower(Helianthus annuus L.)growth attributes.Three different levels of chromium(Cr)i.e.,20, 40,and 60 mg/kg were applied to three varieties of sunflower(G-3,G-9,and G-59).The results of morphological,chemical,and yield p...     

Surfactant enhanced pyrene degradation in the rhizosphere of tall fescue (Festuca arundinacea)

Environmental Science and Pollution Research - The present study was conducted to evaluate the effect of two non ionic surfactants (Tween 80 and Triton X-100), a biosurfactant (Lecithin), and...     

Development of Anticorrosive Poly(Ether-Urethane) Amide Coatings from Linseed Oil: A Sustainable Resource

Polyetheramide(PEtA) resin was synthesized by the condensation polymerization of N,N-bis(2-hydroxy ethyl) linseed oil fatty amide diol (HELA) with resorcinol. It was further treated with different percentage of toluylene 2-4-diisocyanate (TDI) to obtain the urethane modified polyetheramide resins (UPEtA). The structural elucidation of PEtA and urethane modified polyetheramide(UPEtA) were carried out by FT-IR, ¹H-NMR and ¹³C-NMR spectroscopic techniques. These analyses confirm the formation of PEtA and UPEtA. Physico-chemical and physico-mechanical analysis were performed by standard laboratory methods. The resin composition UPEtA-24 showed best physico-mechanical properties with scratch hardness 2.0 kg, impact resistance 150 lb/in. and good bending ability. The thermal stability and curing behavior of polymers were respectively studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal analysis shows that these coatings can be used safely upto 190 °C. The coatings of UPEtA resins were prepared on mild steel strips. The anticorrosive behavior of UPEtA coatings were investigated in acid, alkali, water and xylene. All the coatings exhibit good chemical resistance performance in acid, alkali, saline and organic solvents, while the resin UPEtA-24 shows the best performance.     

Optimisation of rainwater tank design from large roofs: A case study in Melbourne, Australia

Rainwater tanks for larger roof areas need optimisation of tank size, which is often not carried out before installation of these tanks. This paper presents a case study of rainwater tank evaluation and design for large roof areas, located in Melbourne, Australia, based on observed daily rainfall data representing three different climatic regimes (i.e. dry average, and wet years). With the aim of developing a comprehensive Decision Support Tool for the performance analysis and design of rainwater tanks, a simple spreadsheet based daily water balance model is developed using daily rainfall data, contributing roof area, rainfall loss factor, available storage volume, tank overflow and irrigation water demand. In this case study, two (185 m³ and 110 m³) underground rainwater tanks are considered. Using the developed model, effectiveness of each tank under different climatic scenarios are assessed. The analysis shows that both the tanks are quite effective in wet and average years, however less effective in dry years. A payback period analysis of the tanks is preformed which reveals that the total construction cost of the tanks can be recovered within 15-21 years time depending on tank size, climatic conditions and future water price increase rates. For the tanks, a relationship between water price increase rates and payback periods is developed. The study highlights the need for detailed optimisation and financial analysis for large rainwater tanks to maximise the benefits.     

The diagnostic accuracy of intraoperative frozen section biopsy for diagnosis of sentinel lymph node metastasis in breast cancer patients: a meta-analysis

Environmental Science and Pollution Research - Sentinel lymph node (SLN) sampling is important for evaluating the nodal stage of breast cancer when the axillary nodes are clinically free of...     

The environmental Kuznets curve hypothesis for Bangladesh: the importance of natural gas,liquefied petroleum gas,and hydropower consumption

Environmental Science and Pollution Research - Mitigating environmental pollution has become a global agenda keeping the sustainability of socioeconomic and environmental development into...     

Synergistic Effects of Multiple Metal Contaminants on Electrokinetic Remediation of Soils

This article presents a bench‐scale study performed to investigate the removal of heavy metals when they exist individually and in combination in soils. Electrokinetic experiments were conducted using two types of clayey soils, kaolin and glacial till. These soils were contaminated with Cr(VI) only, with Ni(II) only, and with Cr(VI), Ni(II), and Cd(II) combined. It was found that in kaolin, a significant pH variation occurred due to electric potential application, affecting the adsorption‐desorption and dissolution‐precipitation, as well as the extent of migration of the contaminants. In glacial till, however, pH changes were not affected significantly. In both kaolin and glacial till, the migration of Cr(VI) and Ni(II) was higher when they were present individually compared to when they existed together with Cd(II). Cr(VI) migration as single or combined contaminant was lower in kaolin as compared to that in glacial till. This result was due to the low pH conditions created near the anode region in kaolin that led to high Cr(VI) adsorption to the clay surfaces. In glacial till, however, nickel precipitated with or without the presence of co‐contaminants due to high pH conditions in the soil. Overall, this study demonstrates that adsorption, precipitation, and reduction are the significant hindering mechanisms for the removal of heavy metals using electrokinetic remediation. The direction of the contaminant migration and overall removal efficiency depend on the polarity of the contaminant, the presence of co‐contaminants, and the type of soil. © 2001 John Wiley & Sons.