Issues and challenges of Fischer-Tropsch synthesis catalysts.

Depletion of oil and gas resources is a major concern for researchers and the global community. Researchers are trying to develop a way to overcome these issues using the Fischer-Tropsch synthesis (FTS) process. The FTS reaction converts a mixture of hydrogen and carbon monoxide gases into a liquid fuel.

Advances in MXene-based technologies for the remediation of toxic phenols: A comprehensive review.

The pressing global issue of organic pollutants, particularly phenolic compounds derived primarily from industrial wastes, poses a significant threat to the environment. Although progress has been made in the development of low-cost materials for phenolic compound removal, their effectiveness remains limited. Thus, there is an urgent need for novel technologies to comprehensively address this issue.

Optimization of KCO exposure conditions using response surface methodology for CO capture with 2-methylpiperazine and monoethanolamine as promoters.

In this study, the optimization of potassium carbonate (KCO) exposure conditions for CO capture with the use of 2-methypiperazine (2MPz) and monoethanolamine (MEA) as promoters was investigated. The tested operating conditions for the CO capture process included the pH, temperature, KCO dose, gas flow rate, and pressure, and their effect on the CO absorption/desorption rate and CO absorption efficiency was assessed. Response surface methodology (RSM) was also employed to determine the equations for the optimal long-term operating conditions.

One-dimensional modeling of heterogeneous catalytic chemical looping steam methane reforming in an adiabatic packed bed reactor.

Hydrogen production via chemical looping steam methane reforming (CL-SMR) is among the most promising current technologies. This work presents the development in gPROMS Model Builder 4.1.

Evaluation of Organic and Inorganic Foulant Interaction Using Modified Fouling Models in Constant Flux Dead-End Operation with Microfiltration Membranes.

The goal of this study was to elucidate the interaction of complex feed solutions under modified membrane fouling models for constant flux operation. The polyvinylidene fluoride membrane (PVDF) was tested for three types of solutions containing inorganic foulants (Al, Mn, and Fe), organic foulants, and suspended solids at 0.5 mM Ca ionic strength.

Direct Growth of Nitrogen-Doped Carbon Quantum Dots on CoS Passivated on Cotton Fabric as an Efficient Photoelectrode for Water Treatment.

Heterogeneous growth of photocatalysts on different porous substrates is a solution to avoid secondary pollution caused by composite photocatalysts themselves. However, the heterogeneous growth of composite photocatalysts with nitrogen-doped carbon quantum dots (NCQDs) inclusions-introduced during synthesis-impedes the direct growth on the substrate. To overcome this problem, NCQDs were grown on a CoS (NCQDs-G@CoS) layer, decorated on cotton fabric.

Role of inorganic foulants in the aging and deterioration of low-pressure membranes during the chemical cleaning process in surface water treatment: A review.

Low-pressure membrane (LPM) filtration, including microfiltration (MF) and ultrafiltration (UF), is a promising technology for the treatment of surface water for drinking and other purposes. Various configurations and operational sequences have been developed to ensure the sustainable provision of clean water by overcoming fouling problems. In the literature, various periodic physical and/or chemical approaches to the cleaning of LPMs have been reported, but little data is available on the aging of MF/UF membranes that results from the interaction between the foulants and the cleaning agent.

Structural and performance variation of PES/PVDF membranes after exposure to the pretreated feed water of CECs.

In this study, the removal efficiency of chemicals of emerging concerns (CECs) was evaluated under exposure to various doses of UV/HO-based oxidation processes in combination with membrane filtration for three cleaning cycles. Polyethersulphone (PES) and polyvinylidene fluoride (PVDF) materials based membranes were used for this study. The chemical cleaning of the membranes was performed by immersion of the membranes into 1 N HCl followed by adding 3000 mg.

Use of ballasted flocculation (BF) sludge for the manufacturing of lightweight aggregates.

Ballasted flocculation (BF) is an efficient way to remove the turbidity from surface water. The objective of the present study is to optimize the ballast (magnetite), coagulant (poly aluminum chloride) concentration and pH for efficient turbidity removal from surface water. To do this, the sludge produced from an optimized dose of a BF treatment was utilized for the production of lightweight (LW) aggregates by combining it with hard clay and sewage sludge.

Degradation analysis of polymeric pipe materials used for water supply systems under various disinfectant conditions.

Addition of chlorine dioxide (ClO) or sodium hypochlorite (NaOCl) as a disinfectant in municipal water distribution systems is a common practice to deactivate micropollutants, but their impact on the pipe material with long-term exposure has not been discussed in detail. In this study, accelerated aging experiments were conducted for evaluating the oxidation of high-density polyethylene (HDPE), low-density polyethylene (LDPE), unplasticized polyvinylidene chloride (UPVC), and high-impact polyvinylidene chloride (Hi-PVC) pipes. The pipes were immersed in deionized (DI) water, ClO, and NaOCl (2 mg/L, 5 mg/L, and 10 mg/L doses) for 1200 h of aging at 40 °C.

Metal oxide and carbon nanomaterial based membranes for reverse osmosis and membrane distillation: A comparative review.

Commercial membranes typically suffer from fouling and wetting during membrane distillation (MD). In contrast, reverse osmosis (RO) can be subject to the fouling issue if applied for highly saline feed solutions containing foulants (e.g.

Optimization of preoxidation to reduce scaling during cleaning-in-place of membrane treatment.

This study investigated the potential for reducing scaling during chemical cleaning of polyvinylidene fluoride membranes by optimizing preoxidation dose and pH. Membranes were fouled by a solution containing inorganic foulants (aluminum, iron, and manganese), humic acid, and kaolin at a Ca strength of 0.5 mM and varying the preoxidation dose.

A comparison of variations in blocking mechanisms of membrane-fouling models for estimating flux during water treatment.

This study investigates five different fouling models and contributing factors in membrane-filtration blocking mechanisms in a constant-pressure mode. A polyvinylidene fluoride membrane was used to study the fouling effects of a complex mixture of foulants (a latex-bed suspension, soybean oil, and inorganics) on pristine and chemically cleaned membranes in the presence of humic acid. A significance ratio in linear regression results (p-value) was used to assess the contribution of fouling mechanism in each model.

Identification of scaling during clean-in-place (CIP) in membrane water treatment process.

The goal of this study was to identify the scaling from the chemical cleaning of a polyvinylidene fluoride (PVDF) membrane, fouled by treating a solution containing inorganic foulants (Al, Fe, and Mn) in the presence of kaolin and humic acid as a natural organic matter at Ca strength of 0.5 mMole. Chemical cleaning of the membrane was conducted using solutions prepared in deionized water and permeate water (PW), and the accumulation of insoluble salts on the membrane during cleaning were evaluated.

Optimization of membrane modification using SiO for robust anti-fouling performance with calcium-humic acid feed in membrane distillation.

The goal of this study was to prepare a robust anti-wetting and anti-fouling polyethersulfone (PES) membrane for the rejection of a highly saline (NaCl and CaCl·2HO) feed solution containing humic acid (HA) in direct contact membrane distillation (DCMD). Response surface methodology (RSM) was used to determine the optimum formulation of the used materials. The variable factors selected were polydimethyl siloxane (PDMS) and silica (SiO); liquid entry pressure (LEP) and contact angle (CA) were selected as responses.