A novel species Spinonema gracilispiculum sp. n. (Nematoda: Desmodoridae) from the oxygen minimum zone of Eastern Arabian Sea margin

Jacob, Jini, Rayaroth, Anilkumar Padinjare, Useph, Abdul Jaleel Koovapurath, Philip, Rosamma, Damodaran, Rayaroth (2020): A novel species Spinonema gracilispiculum sp. n. (Nematoda: Desmodoridae) from the oxygen minimum zone of Eastern Arabian Sea margin. Zootaxa 4869 (4): 587-598, DOI: 10.11646/zootaxa.4869.4.

Mean and seasonal circulation of the south Indian ocean estimated by combining satellite altimetry and surface drifter observations

The mean velocity field of south Indian Ocean has been derived by combining high resolution maps of sea level anomalies and the surface drifter data from the Global Drifter program from 1993 to 2012 with a resolution of 1/3 × 1/3 degrees in latitude and longitude. The estimated mean velocity field exhibits strong western boundary currents, zonal currents and eastern boundary currents. The Agulhas Current shows a velocity of above 1.5 m s-1 at around 35°S. The distribution of energy associated with the fluctuating motion and the mean flow illustrates that mesoscale variability are particularly relevant in the Mozambique Channel, south of Java and around 40°S. Advection of mesoscale features along the western boundary is evident in the distribution of eddy fluxes. The long-term average monthly surface velocity field exhibits large variations in surface currents. The most change is observed in the South Equatorial Current which shows spatial and temporal variation

Degradation of bisphenol S – a contaminant of emerging concern - by synergistic ozone and percarbonate based AOP

Degradation of bisphenol S was studied using ozone activated by sodium percarbonate and the effectiveness of optimized process was compared with the peroxone process. The influence of several factors including sodium percarbonate concentration, ozone dose, pH, and water matrix were investigated. A synergetic coefficient of 3.84 was achieved for the combination of sodium percarbonate and ozone, confirming the effectiveness of this hybrid process. Scavenging tests revealed, that carbonate radicals, hydroxyl radicals, superoxide radicals, and singlet oxygen contributed to the degradation of bisphenol S. At the same operating condition, degradation effectiveness values of 99% and 81% were obtained by ozone combined with sodium percarbonate and hydrogen peroxide, respectively, demonstrating the superiority of sodium percarbonate over hydrogen peroxide in combination with ozone for the degradation of bisphenol S. Low concentration of inorganic anions had a negligible effect on the degradation, while carbonate ions increased the first-order degradation rate constant by 56%

Spatial and temporal variability of sea surface height of bay of bengal derived from satellite altimetry

The spatial and temporal variability of sea surface height anomaly of Bay of Bengal is derived from satellite altimeter observations for the period of 1993-2008. The data used are the weekly Maps of Sea Level Anomaly with 1/3 x 1/3 longitude and latitude resolution weekly files. Annual average of sea level anomaly field is estimated to understand the long term variability. Empirical Orthogonal Functional analysis has been carried out to derive the spatial structure and temporal amplitude of the variability. The first three modes of EOFs capture 80% of the total variance. The temporal amplitude clearly exhibits the influence of climate modes on the sea level of Bay of Bengal

Simultaneous removal of heavy metals and dyes in water using a MgO-coated Fe3O4 nanocomposite: Role of micro-mixing effect induced by bubble generation

© 2022This study focused on the development of a nano-adsorbent for contaminant removal without the use of any external energy. An eco-friendly Fe3O4@MgO core-shell nanocomposite was synthesized and tested for the removal of a heavy metal, lead (Pb2+) and a dye, rhodamine B (RhB). The addition of H2O2 into the system enabled the self-mixing of the aqueous solution containing Fe3O4@MgO through the generation of bubbles. This system showed an excellent removal efficiency of 99% in just 15 min for Pb2+ and 120 min for RhB, which is far better than the control experiment (without H2O2). The cation exchange mechanism dominated in the removal of heavy metals, while the adsorptive removal of dye proceeded through the H-bonding between Mg(OH)2 and dye molecules. The removal efficiency increased exponentially with the increase of H2O2 at the optimal concentration of 5% and it was effective over a wide pH range. Moreover, the performance of the Fe3O4@MgO–H2O2 system was verified for other heavy metals such as Cd, Ni, Zn, Co, and Cu, demonstrating that the Fe3O4@MgO–H2O2 system can be widely implemented in the treatment of real water matrices contaminated with heavy metals and organic dyes.11Nsciescopu

Advanced Oxidation Processes for Degradation of Water Pollutants—Ambivalent Impact of Carbonate Species: A Review

Advanced oxidation processes (AOPs) hold great promise in the removal of organic contaminants. Reactive oxygen species (ROS) produced in AOPs react with target pollutants to initially form several intermediate compounds that finally undergo complete mineralization. Such observations are reported, especially for laboratory-scale experiments performed in pure water. On the other hand, while considering real contaminated wastewater matrices, particularly industrial effluents, there are many co-existing ions. Carbonate ions are one of the major inorganic ions commonly existing in water resources. Hence, these ions have a significant impact on the respective water treatment processes. This review focused on the effect of carbonate ions on the degradation of pollutants in AOPs. In AOPs, carbonate radicals are formed by the scavenging reaction of the respective ions with ROS. The reactivity of these radicals towards the pollutant varies with respect to the structure and functionality. Therefore, depending on the functionalities of the contaminants, these ions show both positive and negative effects. Thus, this review aims to summarize the effects of carbonate species on the degradation of organic contaminants during AOPs and their environmental impacts. The carbonates enhanced the degradation of several emerging organic pollutants, including aniline, bisphenol A, rhodamine B, acid orange 7, naphthalene, and phenol derivatives. Carbonate presence was also revealed to have a positive contribution in cases of drug degradation, including sulfamethoxazole, propranolol, sulfamethazine, salbutamol, trimethoprim, azithromycin, naproxen, oxcarbazepine, and oxytetracycline

Northern south China sea surface circulation and its variability derived by combining satellite altimetry and surface drifter data

The present study analyses the mean and seasonal mesoscale surface circulation of the Northern South China Sea (NSCS) and determines the influence of El Niño/Southern Oscillation (ENSO). High resolution Eulerian velocity field is derived by combining the available satellite tracked surface drifter data with satellite altimetry during 1993 - 2012. The wind driven current is computed employing the weekly ocean surface mean wind fields derived from the scatterometers on board ERS 1/2, QuikSCAT and ASCAT. The derived mean velocity field exhibits strong boundary currents and broad zonal flow across NSCS. The anomalous field is quite strong in the southern part and the Seasonal circulation clearly depicts the monsoonal forcing. Eddy Kinetic Energy (EKE) distribution and its spatial and temporal structures are determined employing Empirical Orthogonal Function (EOF) analysis. The ENSO influence on NSCS surface circulation has been analyzed using monthly absolute geostrophic velocity fields during 1996 - 1999

Oxidative degradation of benzoic acid using Fe0- and sulfidized Fe0-activated persulfate: A comparative study

Implications of sulfidized Fe-0(nFe/FeS) for the abatement of pollutants of various categories are widely established. In this study, degradation of one of the major organic pollutants, benzoic acid (BA), has been performed using persulfate activated with nFe/FeS. Complete degradation of BA and its transformed product, hydroxybenzoic acid, was observed within 6 min. When the degradation was performed at alkaline pH, the degradation decreased to 8% in the case of Fe-0, but nFe/FeS still showed 100% degradation after 60 min. Iron dissolution and persulfate decomposition in the presence of scavengers showed that both sulfate and hydroxyl radicals were involved in the Fe-0-persulfate system and that the hydroxyl radicals were the major species in the nFe/FeS-persulfate system. The major degradation pathway of benzoic acid was hydroxylation followed by complete mineralization, as supported by the practical removal of total organic carbons (more than 75% within 15 min). The observed results are promising in using perstlfate activated by nFe/FeS for the remediation of various micro-pollutants from a multitude of water sources. (C) 2017 Elsevier B.V. All rights reserved.1195sciescopu