ORCID Profile
0000-0002-1107-131X
Current Organisations
COMSATS University Islamabad
,
University of Agriculture Faisalabad Faculty of Agriculture
,
Nanyang Technological University
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Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6FD00047A
Abstract: Carbon capture and storage (CCS) offers a possible solution to curb the CO 2 emissions from stationary sources in the coming decades, considering the delays in shifting energy generation to carbon neutral sources such as wind, solar and biomass. The most mature technology for post-combustion capture uses a liquid sorbent, amine scrubbing. However, with the existing technology, a large amount of heat is required for the regeneration of the liquid sorbent, which introduces a substantial energy penalty. The use of alternative sorbents for CO 2 capture, such as the CaO–CaCO 3 system, has been investigated extensively in recent years. However there are significant problems associated with the use of CaO based sorbents, the most challenging one being the deactivation of the sorbent material. When sorbents such as natural limestone are used, the capture capacity of the solid sorbent can fall by as much as 90 mol% after the first 20 carbonation–regeneration cycles. In this study a variety of techniques were employed to understand better the cause of this deterioration from both a structural and morphological standpoint. X-ray and neutron PDF studies were employed to understand better the local surface and interfacial structures formed upon reaction, finding that after carbonation the surface roughness is decreased for CaO. In situ synchrotron X-ray diffraction studies showed that carbonation with added steam leads to a faster and more complete conversion of CaO than under conditions without steam, as evidenced by the phases seen at different depths within the s le. Finally, in situ X-ray tomography experiments were employed to track the morphological changes in the sorbents during carbonation, observing directly the reduction in porosity and increase in tortuosity of the pore network over multiple calcination reactions.
Publisher: Elsevier BV
Date: 05-2023
Publisher: Springer Science and Business Media LLC
Date: 02-2022
DOI: 10.1007/S10661-022-09799-8
Abstract: Potentially hazardous element (PHE) contamination of aquifers is an issue of global concern, as this not only affects soil and plants but also exerts a negative impact on livestock. The current study assessed the extent of PHE (cadmium, copper, nickel, and lead) contamination of groundwater, soil, and forage crops in Shorkot, Punjab, Pakistan. Low concentrations of PHEs, particularly Cd and Cu, were found in drinking water which remained below detection limits. The concentrations of Ni and Pb in water s les were 0.1 and 0.06 mg L
Publisher: Wiley
Date: 03-07-2021
Abstract: Strong metal–support interaction (SMSI) is a phenomenon commonly observed on heterogeneous catalysts. Here, direct evidence of SMSI between noble metal and 2D TiB 2 supports is reported. The temperature‐induced TiB 2 overlayers encapsulate the metal nanoparticles, resulting in core–shell nanostructures that are sintering‐resistant with metal loadings as high as 12.0 wt%. The TiO x ‐terminated TiB 2 surfaces are the active sites catalyzing the dehydrogenation of formic acid at room temperature. In contrast to the trade‐off between stability and activity in conventional SMSI, TiB 2 ‐based SMSI promotes catalytic activity and stability simultaneously. By optimizing the thickness and coverage of the overlayer, the Pt/TiB 2 catalyst displays an outstanding hydrogen productivity of 13.8 mmol g −1 cat h −1 in 10.0 m aqueous solution without any additive or pH adjustment, with .9% selectivity toward CO 2 and H 2 . Theoretical studies suggest that the TiB 2 overlayers are stabilized on different transition metals through an interplay between covalent and electrostatic interactions. Furthermore, the computationally determined trends in metal–TiB 2 interactions are fully consistent with the experimental observations regarding the extent of SMSI on different transition metals. The present research introduces a new means to create thermally stable and catalytically active metal/support interfaces for scalable chemical and energy applications.
Publisher: Elsevier
Date: 2016
Publisher: American Chemical Society (ACS)
Date: 21-04-2023
Publisher: American Chemical Society (ACS)
Date: 03-09-2021
Publisher: American Chemical Society (ACS)
Date: 20-09-2022
Publisher: Springer Science and Business Media LLC
Date: 13-01-2015
DOI: 10.1007/S11356-015-4073-Y
Abstract: Crop irrigation with heavy metal-contaminated effluents is increasingly common worldwide and necessitates management strategies for safe crop production on contaminated soils. This field study examined the phytoavailability of three metals (Cd, Cu, and Zn) in two cereal (wheat, maize) and legume (chickpea, mungbean) crops in response to the application of either phosphatic fertilizer or sewage-derived water irrigation over two successive years. Five fertilizer treatments, i.e. control, recommended nitrogen (N) applied alone and in combination of three levels of phosphorus (P), half, full and 1.5 times of recommended P designated as N0P0, N1P0, N1P0.5, N1P1.0, and N1P1.5, respectively. Tissue concentrations of Cd, Cu, Zn, and P were determined in various plant parts, i.e., root, straw, and grains. On the calcareous soils studied while maximum biomass production was obtained with application of P at half the recommended dose, the concentrations of metals in the crops generally decreased with increasing P levels. Tissue metal concentrations increased with the application of N alone. Translocation and accumulation of Zn and Cu were consistently higher than Cd. And the pattern of Cd accumulation differed among plant species more Cd being accumulated by dicots than monocots, especially in their grains. The order of Cd accumulation in grains was maize > chickpea > mungbean > wheat. Mungbean and chickpea straws also had higher tissue Cd concentration above permissible limits. The two legume species behaved similarly, while cereal species differed from each other in their Cd accumulation. Metal ion concentrations were markedly higher in roots followed by straw and grains. Increasing soil-applied P also increased the extractable metal and P concentrations in the post-harvest soil. Despite a considerable addition of metals by P fertilizer, all levels of applied P effectively decreased metal phytoavailability in sewage-irrigated soils, and applying half of the recommended dose of P fertilizer was the most feasible solution for curtailing plant metal uptake from soils. These findings may have wide applications for safer crop production of monocot species when irrigating crops with sewage effluent-derived waters.
Publisher: Informa UK Limited
Date: 04-01-2017
Publisher: Elsevier BV
Date: 07-2017
Publisher: Springer Science and Business Media LLC
Date: 03-05-2020
DOI: 10.1007/S10653-019-00306-6
Abstract: Arsenic (As) is a highly toxic and carcinogenic element. It has received considerable consideration worldwide in recent years due to its highest toxicity to human, and currently, high concentrations observed in the groundwater. Some recent media and research reports also highlighted possible As contamination of groundwater systems in Pakistan. However, there is a scarcity of data about As contents in groundwater in different areas/regions of the country. Consequently, the current study estimated the As concentration in the groundwater used for drinking purpose in 15 peri-urban sites of district Vehari, Pakistan. In total, 127 groundwater s les were collected and examined for As contents in addition to physicochemical characteristics such as temperature, electrical conductivity, pH, total soluble salts, chloride, carbonates, bicarbonates, sodium, potassium, lithium, calcium and barium. Results indicated that the groundwater s les were not fully fit for drinking purposes with several parameters, especially the alarming levels of As (mean As: 46.9 µg/L). It was found that 83% groundwater s les of peri-urban sites in district Vehari have As concentration greater than WHO lower permissible limit (10 µg/L). The risk assessment parameters (mean hazard quotient: 3.9 and mean cancer risk: 0.0018) also showed possible carcinogenic and non-carcinogenic risks associated with ingestion of As-contaminated groundwater at peri-urban sites. Based on the findings, it is anticipated that special monitoring and management of groundwater is necessary in the studied area in order to curtail the health risks associated with the use of As-contaminated drinking water. Moreover, appropriate remediation and removal of As from groundwater is also imperative for the study area before being used for drinking purpose to avoid As exposure and related risks to the local community.
Publisher: Springer Science and Business Media LLC
Date: 20-11-2021
Publisher: Wiley
Date: 03-06-2020
Location: Pakistan
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Wen Liu.