Seawater intrusion vulnerability in the coastal aquifers of southern India—an appraisal of the GALDIT model, parameters’ sensitivity, and hydrochemical indicators

Abstract

An appraisal of seawater intrusion into the coastal aquifers is one of the major issues for groundwater resource management. The GALDIT model applies to the analysis of multiple parameters using systematic GIS techniques for mapping and assessment of seawater intrusion vulnerability. It demarcates the mapping of potential vulnerability that shows a higher vulnerability to seawater intrusion in various parts of the coast and the estimated vulnerability index value of 7.50 and 9.64. An area of 33.0 km² spread in the low-lying coastal area comprising estuaries, salt marshes, and saltpans shows the high vulnerability condition with an estimated vulnerability value of 6.42–7.50. An area of 73.20 km² spread over coastal and alluvial plains experiences moderate vulnerability (temporal salinity in the groundwater sources) with an estimated vulnerability index value of 5.46–6.42. Aquifers underlying coastal uplands (hard rock formations) and some parts of accretionary beaches (2.05 km²) are relatively protected fresh groundwater sources, wherein the estimated vulnerability index is 4.55–5.46. The vulnerability mapping of the GALDIT model using hydrochemical analysis of primary groundwater parameters such as TDS, Cl⁻, HCO₃, and Cl⁻/HCO₃ ratio is validated. Higher concentration of TDS (2637–4162 mg/l) and Cl⁻ (1268–2347 mg/l) is taken for the areas falling under higher vulnerability to seawater intrusion, especially in the placer mining sites and coastal areas facing erosion. Similarly, the groundwater sources of the low-lying areas including estuaries, salt marshes, saltpans, and backwater were noted to have higher values of Cl⁻/HCO₃ with a rationality of 9.87–12.18. Hydrological facies shows the highest concentration of NaCl in the groundwater sources within the proximity of eroded beaches, saltwater bodies, and sand mining areas. A hydrochemical facies evolution (HFE) diagram represents the hydrochemical facies of groundwater elements that shows an intrusion of seawater into the coastal aquifers underlying the very high vulnerable zones. Higher bicarbonate concentration (233–318 mg/l) is noticed in the upland areas and some parts of dunes and accreted beaches, sandy coasts, and uplands. Vulnerability analysis reveals that those areas near saltwater bodies and eroding coasts are prone to lateral and vertical diffusion of saltwater. The geodatabase developed through such modeling studies can help in planning and developing activities for sustainable groundwater resource management in coastal areas.

from Climate Change Skeptic Blogs via hj on Inoreader http://bit.ly/2DgLQnH

Green sol–gel synthesis of novel nanoporous copper aluminosilicate for the eradication of pathogenic microbes in drinking water and wastewater treatment

Abstract

We used a green sol–gel synthesis method to fabricate a novel nanoporous copper aluminosilicate (CAS) material. Nanoporous CAS was characterized using X-ray powder diffraction (XRD), field emission transmission and scanning electron microscopies (FE-TEM/FE-SEM), Fourier transform infrared (FTIR) spectroscopy, and optical analyses. The CAS was also evaluated for use as a promising disinfectant for the inactivation of waterborne pathogens. The antimicrobial action and minimum inhibitory concentration (MIC) of this CAS disinfectant were determined against eight microorganisms (Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Candida albicans, and Aspergillus niger). An antimicrobial susceptibility testing of CAS was measured. Results of disc diffusion method pointed out that the diameters of the zone using well diffusion were wider than disc diffusion methods, and the findings also showed that the MIC of the CAS disinfectant against E. coli, S. enterica, and P. aeruginosa was 100 mg/L within 20 min of contact time. Meanwhile, the MIC of the CAS disinfectant was 100 mg/L within 40 min of contact time for the other strains. The efficacy of antimicrobial action (100%) reached within 20 to 40 min against all tested microbes. Herein, the antimicrobial susceptibility testing of CAS disinfectant showed no toxicity for human and bacterial cells. It can be concluded that nanoporous CAS is a promising, economically, and worthy weapon for water disinfection.

from Climate Change Skeptic Blogs via hj on Inoreader http://bit.ly/2SedJHj

Contamination status and potential release of trace metals in a mangrove forest sediment in Ho Chi Minh City, Vietnam

Abstract

Can Gio district is located in the coastal area of Ho Chi Minh City, southern Vietnam. Discharge of wastewater from Ho Chi Minh City and neighboring provinces to the rivers of Can Gio has led to concerns about the accumulation of trace metals (As, Cu, Cr, Ni, Pb, and Zn) in the coastal sediments. The main objective of this study was to assess the distribution of As, Cu, Cr, Ni, Pb, and Zn in surface and core sediments and to evaluate the contamination status in relation to local background values, as well as the potential release of these selected trace metals from sediments to the water environment. Sediment characteristization, including determination of fine fraction, pH, organic matter, and major elements (Al, Fe, Ca, K, Mg, and S), was carried out to investigate which parameters affect the trace metal enrichment. Fine fraction and Al contents were found to be the controlling proxies affecting the distribution of trace metals while other sediment characteristics did not show any clear influence on trace metals' distribution. Although As concentrations in the sediments were much higher compared to its reference value in other areas, the enrichment factor based on local background values suggests minor contamination of this element as well as for Cr, Cu, and Pb. Risk assessment suggested a medium to very high risk of Mn, Zn, and Ni under acidification. Of importance is also that trace metals in sediments were not easily mobilized by organic complexation based on their low extractabilities by ammonium-EDTA extraction.

from Climate Change Skeptic Blogs via hj on Inoreader http://bit.ly/2HXKzrz

DOE Proposal Sets Hurdles for Efficiency Standards

from Climate Change Skeptic Blogs via hj on Inoreader https://on.nrdc.org/2GsCjNO

Enhancement in combustion, performance, and emission characteristics of a diesel engine fueled with diesel, biodiesel, and its blends by using nanoadditive

Abstract

This article presents the results of investigations carried out to evaluate the improvement in combustion, performance, and emission characteristics of a diesel engine fueled with neat petro-diesel (PD), soybean biodiesel (SB), and 50% SB blended PD (PD50SB) by using carbon nanotube (CNT) as an additive. The acid–alkaline-based transesterification process with sodium hydroxide (NaOH) as a catalyst was applied to derive the methyl ester of SB. A mass fraction of 100 ppm CNT nanoparticle was blended with base fuels by using an ultrasonicator and the physiochemical properties were measured based on EN standards. The measured physiochemical properties are in good agreement with standard limits. The experimental evaluations were carried out under varying brake mean effective pressure (BMEP) conditions in a single-cylinder, four-stroke, and natural aspirated research diesel engine at a constant speed of 1500 rpm. The results reveal that the SB and its blend promote shorter ignition delay period (IDP) that is resulting in lower in-cylinder pressure (ICP) and net heat release rate (NHR) compared to PD. The SB and its blend increase the brake specific fuel consumption (BSFC), and reduce the brake specific energy consumption (BSEC) and exhaust gas temperature (EGT), due to lower heating value, and efficient combustion, respectively. As far as the emission characteristics are concerned, the SB and its blend promote lower magnitude of hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO₂), and smoke emissions compared to PD except for oxides of nitrogen (NO_x) emission. The CNT nanoparticle inclusion with base fuels significantly improves the combustion, performance, and emissions level irrespective of engine load conditions.

from Climate Change Skeptic Blogs via hj on Inoreader http://bit.ly/2TB7JoS

2019: Already a vintage year for climate claptrap

From The Global Warming Policy Forum (GWPF)

It has been an encouraging start to the contest for the year's loopiest climate story.

First out of the blocks is a cracker from the geography department at University College London with the suggestion that Spanish colonisation in the Americas contributed to global cooling.

Early interest is also being shown in a paper that appeared in the Journal of the American Heart Association suggesting that a rise in temperatures stemming from climate change may increase the number of US infants born with congenital heart defects. This presumably opens up a whole new field of science – and funding – investigating the effect of latitude on vast numbers of ailments.

The global drop in temperatures started in 1300, long before the Spanish invaded the Americas. The UCL team suggested that reductions in population after the Spanish conquests and subsequent increases in tropical jungle led to more CO2 being used from the atmosphere.

The report seems to suggest that this amounted to around three parts per million in the atmosphere. If true, this would be a minute amount in an atmosphere that held at the time round 280ppm of CO2. Three ppm is well within any genuine scientific margin of error.

The 'mini ice age' was caused by many natural events and continued until around 1850. It was characterised by numerous variations in temperature across different time periods and regions in the northern hemisphere.

Needless to say the BBC led the media charge and was all over this story. Linking climate change with the genocidal activities of white colonists just ticks so many boxes, even for so-called science correspondents.

Continued here.

from Climate Change Skeptic Blogs via hj on Inoreader http://bit.ly/2WJhpj2

Global Temperature Report: January 2019 – up, due in part to Australia

The global average bulk-layer atmospheric temperature anomaly rose by +0.12 °C (0.22 °F) in January to +0.37°C Global climate trend since Dec. 1 1978: +0.13 C per decade January Temperatures (preliminary) Global composite temp.: +0.37 C (+0.67 °F) above seasonal average Northern Hemisphere.: +0.32 C (+0.58 °F) above seasonal average Southern Hemisphere.: +0.42 C (+0.76 °F)…

from Climate Change Skeptic Blogs via hj on Inoreader http://bit.ly/2TC7RnW

The planet is no longer warming

Guest Post By Javier         We define "warming" as a positive rate of temperature change over time. According to the main hypothesis, warming since 1951 has been due almost exclusively to the increase in GHGs (greenhouse gases), of which CO2 is the most important one. The IPCC does not find anything else…

from Climate Change Skeptic Blogs via hj on Inoreader http://bit.ly/2GteLbs

Here we go again! Media hypes alleged ‘Hottest year’ declarations as 2018 cools, slips to 4th ‘warmest’ – Book excerpt

Another year, another claim of "hottest" or "warmest years." So-called "Hottest year" claims are purely political statements designed to persuade the public that the government needs to take action on man-made climate change. Once again, the media and others are hyping temperature changes year-to-year so small as to be within the margin of error. Such temperature claims [...]

from Climate Change Skeptic Blogs via hj on Inoreader http://bit.ly/2DiWDxF

Rush Limbaugh: The President DID Talk About Climate Change – ‘Trump told them to go pound sand’

http://bit.ly/2td1Ja5 RUSH: You know what else the left is ticked off about today? What did Trump not mention last night in the State of the Union address? He didn't talk about climate change. He didn't talk about it one time, except that he did. They just don't know it. I've looked at a bunch of [...]

from Climate Change Skeptic Blogs via hj on Inoreader http://bit.ly/2HWwM4o

[ASAP] Core–Shell Structured Cyclodextrin Metal–Organic Frameworks with Hierarchical Dye Encapsulation for Tunable Light Emission

Chemistry of Materials

DOI: 10.1021/acs.chemmater.8b04126

from Journals via hj on Inoreader http://bit.ly/2GtlToi

[ASAP] Molecular Simulation of the Catalytic Regeneration of nBuLi through a Hydrometalation Route

Inorganic Chemistry

DOI: 10.1021/acs.inorgchem.8b02910

from Journals via hj on Inoreader http://bit.ly/2Dc5fGw

[ASAP] Preliminary Assignment of Protonated and Deprotonated Homocitrates in Extracted FeMo-Cofactors by Comparisons with Molybdenum(IV) Lactates and Oxidovanadium Glycolates

Inorganic Chemistry

DOI: 10.1021/acs.inorgchem.8b03108

from Journals via hj on Inoreader http://bit.ly/2DejhaA

[ASAP] Divalent Thulium Crown Ether Complexes with Field-Induced Slow Magnetic Relaxation

Inorganic Chemistry

DOI: 10.1021/acs.inorgchem.8b03551

from Journals via hj on Inoreader http://bit.ly/2DdxLaD

[ASAP] Robust Machine Learning Models for Predicting High CO2 Working Capacity and CO2/H2 Selectivity of Gas Adsorption in Metal Organic Frameworks for Precombustion Carbon Capture

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.8b10644

from Journals via hj on Inoreader http://bit.ly/2GuUX7B

[ASAP] Curved Polar Dibenzocoronene Esters and Imides versus Their Planar Centrosymmetric Homologs: Photophysical and Optoelectronic Analysis

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.8b10730

from Journals via hj on Inoreader http://bit.ly/2DWIPdR

[ASAP] Construction of a Novel Z-Scheme Heterojunction with Molecular Grafted Carbon Nitride Nanosheets and V2O5 for Highly Efficient Photocatalysis

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.8b11361

from Journals via hj on Inoreader http://bit.ly/2GtpJO7

[ASAP] Introducing Asymmetry Induced by Benzene Substitution in a Rigid Fused p Spacer of D-p–A-Type Solar Cells: A Computational Investigation

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.8b10963

from Journals via hj on Inoreader http://bit.ly/2GqhQck

[ASAP] Comprehensive Elucidation of Ion Transport and Its Relation to Hysteresis in Methylammonium Lead Iodide Perovskite Thin Films

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.8b11285

from Journals via hj on Inoreader http://bit.ly/2UJodeD

[ASAP] Ratiometric Tuning of Luminescence: Interplay between the Locally Excited and Interligand Charge-Transfer States in Pyrazolate-Based Boron Compounds

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.8b11100

from Journals via hj on Inoreader http://bit.ly/2tbdDBz