Removal of Hazardous Oxyanion Pollutants by Lanthanum (Iii) Hydroxide and Lanthanum (III) - Loaded Ion Exchangers

La(III) loaded poly(hydroxamic acid) chelating resin (LaPHA), lanthanum hydroxideloaded poly(hydroxamic acid) chelating resin (LaOHPHA) and lanthanum hydroxide (La(OH)3) were prepared and evaluated as sorbents for removal of As(V), As(III) and Cr(VI) from aqueous solution. LaPHA was prepared by loading lanthanum(III) onto PHA resin which was prepared by the reaction of PMA with hydroxyl amine hydrochloride in alkaline medium. LaOHPHA was prepared by treating LaPHA with ammonia solution and La(OH)3 was prepared by neutralizing LaCl3 solution with ammonia solution. In order to understand the sorption characteristics of As(V), As(III) and Cr(VI) by the sorbents, batch and column studied were performed under various experimental conditions. The parameters studied were pH, contact time, isotherm study, iv temperature, sorbent dosage, presence of competitive anions, flow rate, sorptiondesorption study and industrial wastewater treatment. The results of batch study indicated that the sorption process was pH dependent and endothermic. Kinetic study showed that uptake of As(V) ion by all of the sorbents reached equilibrium after about 15 hours and about 10 hours for Cr(VI) by La(OH)3. The maximum sorption capacity of LaPHA for As(V) at room temperature determined from the Langmuir isotherm was 14.8 mg-As/g-sorbent compared to that of LaOHPHA for As(V) which was 17.7 mg-As/g-sorbent, while the maximum sorption capacity of La(OH)3 for As(V) was 133.3 mg-As/g-sorbent and for Cr(VI) was 33.1 mg-Cr/g-sorbent. The results also showed that the La(OH)3 in the PHA resin (LaOHPHA) was more stable in acidic medium compared to the La(OH)3. The uptake increased with increasing sorbent dosage and also increased by increasing in temperature. In the presence of competitive ions, metal uptake decreased and it was found that phosphate ion is the most effective one. In desorption study, As(V) could be removed almost quantitatively from LaPHA and LaOHPHA by eluting with 0.4M and 0.2M NaOH solutions, respectively. The column with LaPHA could be used for not more than 3 cycles and 2 cycles for LaOHPHA. Both LaPHA and LaOHPHA resins were found effective to remove arsenic from wastewater samples from wood treatment industry. The percentages of arsenic removal from wastewater by the sorbents were higher for lower v concentrations samples. More than 90% removal was obtained from the sample with the lowest arsenic concentration

The optimum condition for the synthesis of carbon nanofibers on activated carbon to remove lead from aqueous solution

Optimum process condition for the production of Carbon Nanofibers (CNFs) to remove lead ion (Pb) from aqueous solution is reported here. The CNFs were produced on the catalyst (Ni2+) impregnated palm oil-based cheap Powder Activated Carbon (PAC). Locally fabricated Chemical Vapour Deposition (CVD) system was used while acetylene (C2H2) was the carbon source. The porous nano-composite product is named “PAC-CNFs”, which was synthesized through a process using impregnated oil palm shell based PAC as a solid substrate. Design Expert 6.0.8 software was used to design the experimental plan and to determine the optimized process parameters for the growth of CNFs by using sorption capacity for Pb2+ by the PAC-CNFs adsorbent, as a response. The effect of different factors on the growth of CNFs including the temperature of CNFs growth (550 to 750 °C), time of growth (30 to 60 min), and the ratio of input C2H2/H2 gases (0.25 to 1.0) was evaluated. The predicted values for the sorption capacity of Pb2+ by the PAC-CNFs were in close agreement with the experimental data (R2 = 0.99). The optimal process condition: temperature for the growth of CNFs, time, and C2H2/H2 ratio was determined as 637 °C, 30 min, and 1.0, respectively. The CNFs grown under the optimized condition exhibited sorption capacity of 77 mg/g in removing Pb2+ from synthetic wastewater containing lead (Pb2+) ion

Correction to: Two years later: Is the SARS-CoV-2 pandemic still having an impact on emergency surgery? An international cross-sectional survey among WSES members

Background: The SARS-CoV-2 pandemic is still ongoing and a major challenge for health care services worldwide. In the first WSES COVID-19 emergency surgery survey, a strong negative impact on emergency surgery (ES) had been described already early in the pandemic situation. However, the knowledge is limited about current effects of the pandemic on patient flow through emergency rooms, daily routine and decision making in ES as well as their changes over time during the last two pandemic years. This second WSES COVID-19 emergency surgery survey investigates the impact of the SARS-CoV-2 pandemic on ES during the course of the pandemic. Methods: A web survey had been distributed to medical specialists in ES during a four-week period from January 2022, investigating the impact of the pandemic on patients and septic diseases both requiring ES, structural problems due to the pandemic and time-to-intervention in ES routine. Results: 367 collaborators from 59 countries responded to the survey. The majority indicated that the pandemic still significantly impacts on treatment and outcome of surgical emergency patients (83.1% and 78.5%, respectively). As reasons, the collaborators reported decreased case load in ES (44.7%), but patients presenting with more prolonged and severe diseases, especially concerning perforated appendicitis (62.1%) and diverticulitis (57.5%). Otherwise, approximately 50% of the participants still observe a delay in time-to-intervention in ES compared with the situation before the pandemic. Relevant causes leading to enlarged time-to-intervention in ES during the pandemic are persistent problems with in-hospital logistics, lacks in medical staff as well as operating room and intensive care capacities during the pandemic. This leads not only to the need for triage or transferring of ES patients to other hospitals, reported by 64.0% and 48.8% of the collaborators, respectively, but also to paradigm shifts in treatment modalities to non-operative approaches reported by 67.3% of the participants, especially in uncomplicated appendicitis, cholecystitis and multiple-recurrent diverticulitis. Conclusions: The SARS-CoV-2 pandemic still significantly impacts on care and outcome of patients in ES. Well-known problems with in-hospital logistics are not sufficiently resolved by now; however, medical staff shortages and reduced capacities have been dramatically aggravated over last two pandemic years

Extraction of Solar Module Parameters using a Novel Optimization Technique

The parameters of a Photovoltaic (PV) model are pivotal in gauging its efficiency under varying sunlight irradiances, temperatures, and different load scenarios. Determining these PV model parameters poses a complex non-linear optimization challenge. This study is based on a new metaheuristic optimization algorithm called the Pelican Optimization Algorithm (POA) to discern the unknown parameters of the PV model. The suggested POA algorithm underwent testing using a monocrystalline panel, encompassing its single-diode configuration. The objective function is designed to minimize the root of the mean squared errors between the predicted and actual current values, adhering to specific parameter constraints. Various statistical error metrics were utilized to emphasize the performance of the proposed algorithm. A comparative analysis with other well-established algorithms was conducted, indicating that POA stands out as highly competitive since it showcases superior efficiency in parameter identification compared to its counterparts

The Thripidae subfamily Sericothripinae (Thysanoptera) from Saudi Arabia with a new species of Hydatothrips Karny

Rasool, Iftekhar, Soliman, Ahmed M., Alattal, Yehya Zaki, Al Dhafer, Hathal M. (2021): The Thripidae subfamily Sericothripinae (Thysanoptera) from Saudi Arabia with a new species of Hydatothrips Karny. Zootaxa 4908 (1): 29-40, DOI: https://doi.org/10.11646/zootaxa.4908.1.

Metal removal from industrial wastewater by a novel carbon nanomaterial.

Recent application of nanomaterials as adsorbent for heavy metals removal has shown remarkable results which is largely due their mechanical and physical properties. In this work, feasibility of using novel carbon nanomaterials as adsorbent for the removal of copper, nickel and lead ions from an industrial wastewater by the adsorption process was investigated. The adsorbent used was a composite carbon nanomaterials (CNMs) grown on substrate granular activated carbon (GAC) made from Palm Kernel shell (PKS) of mesh size 8x12.Characterization of the adsorbent was carried out using FESEM, TEM. The effect of pH and adsorbent dosage on metals uptake from solution was investigated. The results showed successful growth of CNMs on the GAC, the adsorption of lead, copper and nickel metals ions was best at pH 5, while maximum capacity was recorded at 1 g/L dosage of adsorbent for lead and copper while nickel was at 2 g/L. The order of affinity for the metals ions by the adsorbent was Pb> Cu >Ni

Adsorption of copper, nickel and lead ions from synthetic semiconductor industrial wastewater by palm shell activated carbon

Granular activated carbon produced from palm kernel shell was used as adsorbent to remove copper, nickel and lead ions from a synthesized industrial wastewater.Laboratory experimental investigation was carried out to identify the effect of pH and contact time on adsorption of lead, copper and nickel from the mixed metals solution. Equilibrium adsorption experiments at ambient room temperature were carried out and fitted to Langmuir and Freundlich models. Results showed that pH 5 was the most suitable, while the maximum adsorbent capacity was at a dosage of 1 g/L, recording a sorption capacity of 1.337 mg/g for lead, 1.581 mg/g for copper and 0.130 mg/g for nickel. The percentage metal removal approached equilibrium within 30 min for lead, 75 min for copper and nickel, with lead recording 100 %, copper 97 % and nickel 55 % removal, having a trend of Pb2+ > Cu2+ > Ni2+ . Langmuir model had higher R2 values of 0.977, 0.817 and 0.978 for copper, nickel and lead respectively, which fitted the equilibrium adsorption process more than Freundlich model for the three metal

Growth of carbon nanomaterial on granular activated carbon

Since the discovery of carbon nanotubes (CNT) and subsequent Carbon Nanomaterials (CNMs), there has been an ever increased academic and industrial interest on there various fields of application due to their exceptional mechanical and electrical properties. In this work, granular activated carbon (GAC) made from palm Kernel shell (PKS) of mesh size 8x12 was impregnated with nickel as substrate catalyst for the growth of Carbon Nanomaterials (CNMs) in a chemical decomposition (CVD) reactor. Various percentage by weight of the nickel (1%, 3%, 5% and 7%) were impregnated on the GAC surface for CNM growth. The CNM growth took place at a fixed reaction temperature and gas flow rates for both the hydrogen gas and carbon source. Characterization of the novel composite material was carried out by using SEM, FESEM and TEM. The results show that growth was successful as at 1% nickel impregnation, while a denser network distribution and rougher surface of CNM was observed at 7% nickel. The growth of CNMs on a larger substrate GAC should make handling of the CNMs easier and it is expected to also open new doors of application in water treatment and oil refining

Efficient lead sorption from wastewater by carbon nanofibers

Wastewater from many industries contains toxic metal ions, which should be removed before water is released into the environment. Many adsorbents have been developed to remove metals, but their efficiency should be improved by, e.g., increasing surface area. Here, we tested the use of carbon nanofibers synthesized on the surface of activated carbon, to remove lead ions (Pb2?). We studied the effect of carbon nanofiber dose, pH, contact time and agitation speed on the sorption capacity. The best conditions were with nanofiber dose of 0.25 g/L, pH of 5.5, contact time of 60 min and agitation speed of 200 rpm. The nanocomposite product was also used for the removal of lead from industrial wastewater. We also found a successful removal of 67 % of lead ions from semiconductor wastewater sample

Modification of powdered activated carbon for the production of Carbon Nanofibers (CNFs)

In the present work, powdered activated carbon (PAC) was modified and used for the production of carbon nanofibers (CNFs). The modification of PAC was done by the impregnation of nickel on the surface of the activated carbon using the wet impregnation method. Variable weight percentage ratios of the catalyst (nickel) ratio were used. The nanofibers were synthesized on the surface of modified PAC by using the Chemical Vapor Deposition (CVD) method at a Temp. of ~ 680º C for one hour in the presence of acetylene as a carbon source. FESEM, TEM, and TGA were used for the characterization of the produ