Total iron is one of the problematic contaminants existing in the landfill leachate, which may lead to both ground and surface water pollution. This study was conducted to find out the potential of a ...low-cost composite adsorbent (COM) to treat total iron in landfill leachate using batch sorption experiments. The COM was composed mainly of brick-and-mortar waste and biochar with small amounts of granular activated carbon (GAC) and natural zeolite. Both kinetic and adsorption isotherm experiments were conducted for the COM as well as for its ingredients individually, to optimize the contact time and mass of the adsorbent, respectively. The removal efficiency of the COM was 95.0%, whereas that of high-cost zeolite and GAC were 89.7% and 93.0%, respectively. The initial total iron concentration, stirring speed, temperature, and initial pH were optimized for the COM. The total iron removal efficiency increased with the increment of the initial total iron concentration, stirring speed and temperature, and the reduction of the initial pH of the influent. Finally, a verification test was conducted with the COM at the optimum conditions. Four replicates were tested. All the replicates gave an average removal efficiency of 99.2 %. The average adsorption capacity was 1.3 mg/g, and the measurements were fitted the best with a Langmuir isotherm model with
R
2
equal to 1. Hence, the COM has the potential to be applied as a reactive/packing medium in any treatment process of landfill leachate or wastewater of the similar characteristics as landfill leachate.
The present investigation was aimed at assessing the efficacy of N1-(2-chloro-4-pyridyl)-N3-phenylurea (CPPU) and salicylic acid on fruit retention, yield, and quality of mango cv. Dusehri. The ...research was carried out at the Department of Fruit Science, Punjab Agricultural University, Ludhiana, India. The experiment was conducted simultaneously at two different locations for two cropping seasons during 2019-20 and 2020-21. Fruit retention enhancing treatments of 2,4-Dichlorophenoxyacetic acid (2,4-D) (@20 ppm), CPPU (@5, 10, and 15 ppm), and salicylic acid (@100, 200, and 300 ppm) were applied at pea stage of fruit growth. Experimental plants were observed for various reproductive, yield, and fruit quality parameters. The results indicated that foliar application of CPPU (T6-CPPU @10 ppm) significantly enhanced fruit retention during marble and harvest stages at both locations in both seasons. The novel growth hormone also improved fruit yield, fruit weight, and fruit quality in mango cv. Dusehri. Foliar applied salicylic acid recorded intermediate values for observed parameters. Therefore, foliar application of CPPU can be considered as a better alternative to 2,4-D for fruit drop management of mango.
Utilizing internally available functional groups, a simple protocol for the efficient synthesis of phosphorus-based indenes, indenones, benzofurans, and isochromenes via intramolecular cyclization of ...allene intermediates/precursors is generated; the latter intermediates/precursors are conveniently obtained through aldehyde-, alkylidene-, and hydroxyl-functionalized propargyl alcohols and P(III)-Cl precursors. The structures of key products have been unequivocally confirmed by X-ray crystallography.
Dopamine (DA) is one of the chief neurotransmitters present in the central nervous system of mammals. Therefore detection of DA in presence of various analytes like paracetamol has great importance. ...In the current work, we are proposing that Triton X-100 (TX-100) pretreated carbon paste electrode (CPE) can be useful to detect the DA selectively in presence of PA. After the pretreatment CPE can detect DA in presence of PA effectively. Cyclic voltammetry was employed to observe the amplified electron transfer reaction between the modified CPE and DA. To understand electron transfer regioselectivity at the TX-100 pretreated CPE, a dual descriptor was used. The prepared electrode showed satisfactory stability when kept under ambient conditions. The proposed approach also showed excellent analytical applicability to identify DA and PA in commercial formulations. The scope of the work is limited to detecting DA in presence of PA. We will consider the other interferes for future works.
Our aim was to describe the numbers and distribution of patients with different types of thalassemia and to assess the standards of care in all thalassemia treatment centers throughout Sri Lanka and ...the success of the ongoing prevention programme.
This cross-sectional island-wide survey was conducted by two trained medical graduates, who visited each thalassemia center to collect data from every patient, using a standardized form. Data was collected through review of patient registers and clinical records.
We collected data on 1774 patients from 23 centers. 1219 patients (68.7%) had homozygous β-thalassemia, 360 patients (20.3%) had hemoglobin E β-thalassemia, and 50 patients (2%) had sickle β-thalassemia. There were unacceptably high serum ferritin levels in almost all centers. The annual number of births of patients with β-thalassaemia varied between 45-55, with little evidence of reduction over 19 years.
Central coordination of the treatment and ultimately prevention of thalassemia is urgently needed in Sri Lanka. Development of expert centers with designated staff with sufficient resources will improve the quality of care and is preferred to managing patients in multiple small units.
It is challenging to create an electrocatalyst for water electrolysis that is long-lasting, highly efficient, and inexpensive for both the hydrogen evolution reaction (HER) and oxygen evolution ...reaction (OER). In this work, we have synthesized an ordered NiFe-layered double hydroxide (LDH)/RuSe2 heterostructure for electrochemical water splitting reaction. The synthesized heterostructure electrode NiFeLDH/RuSe2 exhibits exceptional HER and OER performance as it produces a current density of 10 mA cm–2 at 60 and 268 mV overpotential, respectively. Very low Tafel slope values of 70 and 69 mV dec–1 for the HER and OER, respectively, imply a fast charge transfer process. Additionally, for the HER and OER processes, even after 40 h, the synthesized NiFeLDH/RuSe2 heterostructure electrodes demonstrate long-term endurance. Insights into interfacial electron transfer are provided by Mott–Schottky experiments, which signifies the creation of the p–n junction in NiFeLDH/RuSe2, which helps in the transition of electrons from n-type NiFeLDH to p-type RuSe2. The formation of the heterojunction enhances the active sites to adsorb H+ and OH– ions, and hence better OER and HER processes are achieved. Transmission electron microscopy clearly depicts the formation of different interfaces at multiple points that was assigned to the interplanar distance of NiFeLDH and RuSe2.
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In this paper, we introduce the notion of (ω-F)-contraction and presented fixed point results for such contractions. Thereafter, by using the technique of fixed point method, we ...propose a simple solution for a nonlinear integral equation. The effectiveness of this fixed point approach is illustrated by numerical example.
The ability of a composite adsorbent composed primarily of various waste materials to adsorb heavy metals, NH
-N, and chemical oxygen demand (COD) from landfill leachate was investigated through ...batch sorption experiments. The study determined the optimal contact time and adsorbent dosage for the removal of Pb, Zn, Cu, Fe, NH
-N, and COD to be 15, 90, 30, 180, 30, and 30 min, respectively. The corresponding optimum adsorbent dosages were determined to be 5, 30, 5, 15, 5, and 30 g, respectively. The composite adsorbent exhibited high removal efficiencies, achieving the following maximum values: 96.4% for Pb, 92.7% for Zn, 60.3% for Cu, 87.1% for Fe, 75.0% for NH
-N, and 67.5% for COD. Pb and Fe showed the best fit with a Langmuir isotherm model, with corresponding adsorption capacities of 0.0165 and 1.14 mg/g, respectively. For Zn, Cu, NH
-N, and COD, the equilibrium data demonstrated the best fit with an Elovich isotherm model, with adsorption capacities of 0.004, 0.005, 0.016, and 4.29 mg/g, respectively. The kinetic data followed the pseudo-second-order kinetic model. It presented a potential solution for the disposal of the waste from which it was derived.
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•Synthesis of PANI doped with Fe3O4 and GO hydrogels (H-PANI/Fe-GO) for selective and sensitive detection of heavy metal ions (HMIs) in aqueous solution.•The limit of detection (LOD) ...for the H-PANI/Fe-GO sensor was calculated by using the 3σ formula and was found to be 5.15 nM for Pb+2.•The selectivity of H-PANI/Fe-GO/GCE was examined in the presence of 1 μM of Pb+2 with 1 μM concentration of Cr+3, Fe+2, Ni+2 and K+ ions.•The reproducibility is an important parameter that was evaluated by using four different H-PANI/Fe-GO/GCE electrodes and its relative standard deviation (RSD) was found to be 4.194 % for Pb+2 detection, which is a clear indication that the electrode holds decent reproducibility.•The stability of the H-PANI/Fe-GO/GCE was verified by self-storing, the sensor displayed a stability retention of 97.23 % for Cd+2, 84.89 % for Pb+2, 92.00 % for Cu+2 and 96.96 % for Hg+2 over 14 days of stability.
Heavy metal ion (HMI) pollution is threat to human health and environment. Here, a sensor for the electrochemical detection (ECD) of Pb+2 along with simultaneous detection of Cd+2, Cu+2 and Hg+2 utilizing the synergic effect of dopants like graphene-oxide (GO) and iron oxide (Fe3O4) into hydrogels of polyaniline (H-PANI/Fe-GO) displays an excellent square wave anodic stripping voltammetry (SWASV) performance towards Pb+2, with an impressive limit of detection (LOD) of 5.15 nM. The oxidative peaks were observed for simultaneous detection at −0.7306, −0.4899, −0.0092 and 0.3417 V vs. Ag/AgCl for Cd+2, Pb+2, Cu+2 and Hg+2 with good sensitivity, reproducibility and stability. Additionally, H-PANI/Fe-GO sensor is effectively employed to detect Pb+2 in real water samples.
The solid transportation problem (STP) is a three-dimensional optimization problem concerned with minimizing total costs while meeting supply and demand limitations by utilizing a variety of ...transportation modes, referred to as conveyances. This study examines the application of the STP to a logistic problem related to the milk distribution problem. Here, the goal is to efficiently deliver milk from a production facility to multiple retail outlets, considering both the cost of transportation and time of delivery as the two primary objectives of the solid transportation problem. Hence, the bi-objective solid transportation problem (BOSTP) is solved, supposing its constraints are fuzzy due to various unpredictable factors during the transportation period. These uncertain values are initially de-fuzzified into the equivalent crisp values using the α-cut approach. Later, the STP is solved with single objectives at once using Vogel’s approximation method. This mathematical model is then formulated to optimize the total transportation cost and time and solved using the hierarchical order goal programming technique to determine the most cost-effective and time-efficient route. The results show that the hierarchical order goal programming technique minimizes the total transportation cost and time while improving the effectiveness of milk distribution.
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