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The present study aimed to investigate the feasibility of blended amine absorbents in improving the CO2 alkanolamine-based absorption of multicycle integrated absorption–mineralization (multicycle IAM) under standard operating conditions (20–25 °C and 1 atm). Multicycle IAM is a promising approach that transforms CO2 emissions into valuable products such as carbonates using amine solvents and waste brine. Previously, the use of monoethanolamine (MEA) as an absorbent had limitations in terms of CO2 conversion and absorbent degradation, which led to the exploration of blended alkanolamine absorbents, such as diethanolamine, triethanolamine, and aminomethyl propanol (AMP) combined with MEA. The blended absorbent was evaluated in terms of the absorption performance and carbonate production in continuous cycles of absorption, precipitation/regeneration, and preparation. The results showed that the fourth cycle of the blend of 15 wt.% AMP and 5 wt.% MEA achieved high CO2 absorption and conversion efficiency, with approximately 87% of the absorbed CO2 being converted into precipitated carbonates in 43 min and a slight degradation efficiency of approximately 45%. This blended absorbent can improve the efficiency of capturing and converting CO2 when compared to the use of a single MEA, which is one of the alternative options for the development of CO2 capture and utilization in the future.

Anthropogenic emissions of greenhouse gases into the atmosphere is inducing global warming, ocean acidification, polar ice melting, rise in sea level, droughts and hurricanes, thus threatening human health and the global economy. Therefore, there is a need to develop cost-effective technologies for CO2 capture. For instance, solution absorption is promising due to a large processing capacity, high flexibility and reliability, and rich experience in engineering applications. Nonetheless, actual commercial solutions, solvents and processes for CO2 capture suffer from slow reaction kinetics, low absorption capacity, high-energy consumption, susceptibility to corrosion, toxicity, low stability and high costs. Therefore, current research focuses on developing more economical, effective, green and sustainable technologies. Here we review 2015–2020 findings on CO2 capture using liquid absorption methods. Methods are based on various solutions, solvents and processes such as carbonate solution, ammonia solution, amine-based solution, ionic liquid, amino acid salt, phase changing absorbent, microcapsulated and membrane absorption, nanofluids and phenoxide salt solution. We discuss absorption performance, absorption mechanism, enhancement pathways and challenges. Amine- and NH3-based absorbents are widely used, yet they are limited by high regeneration energy, corrosiveness and degradation, reagent loss and secondary pollution caused by NH3 escape. Phase changing absorbents are getting more attention due to their lower cost and lower energy penalty. The incorporation of membrane and microencapsulation technologies to absorbing solvents could enhance CO2 absorption performance by reducing corrosion and increasing selectivity. Adding nanoparticles to solvents could improve CO2 absorption performance and reduce energy requirement. Besides, solvent blends and promoter-improved solvents performed better than single and non-promoted solvents because they combine the benefits of individual solvents and promoters.

With an increasing population, world agriculture is facing many challenges, such as climate change, urbanization, the use of natural resources in a sustainable manner, runoff losses, and the accumulation of pesticides and fertilizers. The global water shortage is a crisis for agriculture, because drought is one of the natural disasters that affect the farmers as well as their country’s social, economic, and environmental status. The application of soil amendments is a strategy to mitigate the adverse impact of drought stress. The development of agronomic strategies enabling the reduction in drought stress in cultivated crops is, therefore, a crucial priority. Superabsorbent polymers (SAPs) can be used as an amendment for soil health improvement, ultimately improving water holding capacity and plant available water. These are eco-friendly and non-toxic materials, which have incredible water absorption ability and water holding capacity in the soil because of their unique biochemical and structural properties. Polymers can retain water more than their weight in water and achieve approximately 95% water release. SAP improve the soil like porosity (0.26–6.91%), water holding capacity (5.68–17.90%), and reduce nitrogen leaching losses from soil by up to 45%. This review focuses on the economic assessment of the adoption of superabsorbent polymers and brings out the discrepancies associated with the influence of SAPs application in the context of different textured soil, presence of drought, and their adoption by farmers.

This paper mainly focuses on the utilization of reversible carbonation reaction of CaO to capture $$\\text{CO}_{2}$$ from the flue gas. The operating analysis regarding the effects of superficial gas velocity, the particle diameter and the calcination/carbonation cycle number on the carbonation process has been performed and compared to experimental data. It is concluded that in order to optimize the carbonation process the superficial gas velocity can decrease gradually during the reaction and smaller-sized absorbent should be chosen. However, the limits of superficial gas velocity and absorbent size need to be taken into consideration as well to avoid entrainment.

The innovation of novel absorbing materials using composite materials and nanotechnology is of new trends for many researches. Here, the present study is concerning to enhance the distilled water productivity of a proposed solar still (PSS) using novel absorbing materials. The absorbing material is composed of chitosan (obtained from waste shrimp shells), ethylene diamine tetraacetic acid (EDTA), and Chrysopogon zizaniodes (Vetiver). The combination of these materials is coined as CHEDZ, and it acts as a super absorbent polymer that is coated on the stepped solar still. Evaporation rate increases due to this absorbent, which further increases the yield of the still. In this present study, the PSS is compared with the conventional solar still (CSS) for the use of assessing the yield of freshwater in the same atmospheric circumstance. The experimental setup was performed through the period from December to February 2020 in the Indian climatic condition. The freshwater productivity was improved to 3.05 L/day while the yield of the CSS is 2.47 L/day. The increase in efficiency obtained from a PSS is 39.71% more than the productivity attained from the CSS. The energy efficiency of the PSS is 18.34% and the exergy efficiency is 0.45%.

Due to water scarcity challenges, efficient management of irrigation water is becoming crucial. Water use efficiency (WUE) involves increasing crop productivity without increasing water consumption. This study was carried out to study the effect of hydrogel, deficit irrigation and soil type on WUE, soil hydro-physical properties and lettuce productivity. For this purpose, four irrigation treatments (100%, 85%, 70% and 60% of full irrigation requirements), four hydrogel concentrations (0, 0.1, 0.2 and 0.3% w/w) and three soil textural classes (clay, loamy sand, and sandy-clay soil) were conducted in pot experiment at open field during two consecutive seasons. The results revealed that crop growth parameters and soil hydro-physical properties were significantly affected by hydrogel application rates. Hydrogel addition significantly enhanced head fresh and dry weights, chlorophyll content, number of leaves and WUE. Application of hydrogel at 0.3% and 85% of irrigation requirements achieved the highest WUE without significant yield reductions. Changes in the studied hydro-physical properties of soil were more dependent on soil texture and hydrogel application rate than on the amount of irrigation water. The significant decrease in soil saturated hydraulic conductivity and bulk density confirms that super absorbent hydrogels could be recommended to improve soil water retention and enhance water use efficiency under deficit irrigation conditions.

Background Silicone-coated self-adhesive absorbent (SSA) and transparent films with absorbent (TFA) dressings are reportedly effective postoperative knee surgery dressings; however, there have been no direct comparative studies on these two innovative dressings over the hip areas. In this study, we aimed to compare user satisfaction and potential complications between TFA and SSA dressings for the hip area. Methods This prospective randomized controlled trial was conducted at a tertiary hospital. The hip side to receive the polyurethane film with SSA dressing (Mepilex ® Border Post-Op) was randomly allocated. The other side of the hip was covered with TFA (OPSITE Post-Op). Participants were scheduled for follow-ups 7 and 14 days after the initial application. Between-group outcomes were compared using a two-sample t-test or Wilcoxon signed-rank test for continuous variables and McNemar’s chi-square test for categorical variables. Results Thirty-two participants (30 − 60 years) without a history of hip surgery were included in the study. The participants were predominantly female, with a mean age of 42.8 years. Pain, difficulties in daily activities, and satisfaction scores were similar between the groups. However, moisture accumulation was significantly higher with the TFA dressing (37.9% vs. 13.8%, p  < 0.01), with more dressing failures (34.5% vs. 20.7%, p  = 0.016) and complications (37.9% vs. 17.2%, p  = 0.012) at the 14-day follow-up than with the SSA dressing. Conclusions SSA dressings are preferable for hip wound care because of better moisture management, fewer dressing changes required, and fewer complications if applied for > 7 days. Both dressings offered high user satisfaction, minimal pain, and minor difficulties in daily activities.

Hydrogels have attracted great attention as good adsorbents due to their extraordinary water retention capacity, unique hydrophilic nature, biocompatibility, and abundance in availability. In this work, a superabsorbent polymer (SAP) hydrogel and its composite were synthesized, with the introduction of activated charcoal (SAP-AC) for deep removal of the ecotoxic organic dye methylene blue (MB). The formation of the hydrogel was confirmed by FTIR analysis, and scanning electron microscopy (SEM) revealed the appearance of a porous microstructure due to the incorporation of AC. A continuous upflow column was set up, and the adsorption parameters were optimized using an experimental Doehlert uniform array design. The residual concentration of MB was analyzed by UV-Vis spectrophotometry at 665 nm (λmax). The experimental data were also discussed in terms of adsorption kinetics and adsorption isotherm models. Accordingly, MB adsorption followed pseudo second-order kinetics and better fits the Freundlich isotherm, suggesting a chemisorption mechanism and a multilayer MB adsorption system. The maximum adsorption capacity was 202.84 mg g−1 (96.96%) using the SAP and 213.2 mg g−1 (99.48%) using the SAP-AC. The present study proved that the synthesized composite hydrogel has good activity and selectivity for deep removal of the MB dye and can be effectively used in wastewater treatment.

The main focus of this study was on using radiation to make an ultra-absorbent hydrogel (UAH) from sodium alginate (SA) and gelatin (GL) biopolymers. This UAH can effectively handle water and nitrogen in wheat farming during drought stress. The hydrogel was synthesized by gamma irradiation-induced SA/GL/polyacrylamide crosslinking at 10–40 kGy. Varying SA/GL ratios affected swelling and the gel fraction of SA/GL/PAm hydrogels. The (SA/GL 17/83) hydrogel exhibited a 40.03 g/g swelling degree, while increasing SA content resulted in higher swelling, peaking at 75.5 g/g for (SA/GL 83/17). This indicated a synergistic interaction between SA and GL. The gel fraction also increased from 76.8 to 90.3%, with a higher GL content reflecting increased crosslinking. After multiple hydrolysis cycles, the hydrogel achieved 1293 (g/g) swelling and 36 days of water retention. When applied to wheat ( Triticuma estivum ) under drought stress, it significantly improved shoot length (18%), root length (43%), shoot fresh weight (49%), and shoot dry weight (51%) under extreme drought. The significant increases in protein and carbohydrate content in both shoots (up to 32% and 19%, respectively) and grains (up to 21% and 24%, respectively), along with the reduction in proline content (up to 38%), demonstrate that ultra-absorbent hydrogel (UAH) effectively enhances nitrogen content, photosynthesis, and overall plant health in wheat under varying drought stress levels. This novel SA/GL-based UAH holds promise for addressing water scarcity and agricultural challenges, offering a sustainable solution for water and nitrogen management under drought stress.

The world is facing a severe shortage of freshwater, and so we are in urge to fetch new technologies to resolve water scarcity. To desalinate saline water, the single-sloped solar still (SSSS) has proven to be a viable option with much affordability. This research work concentrates on the usage of nanomaterial on the absorbent layer to improve the thermal conductivity of the basin area and thus the distillate produced per hour. The micro-coated and nano-Fe 2 O 3 particles were employed and analyzed. The experiment proved that the implementation of this idea had a better productivity rate. The nanoparticles and microparticles were added at weight proportions of 10%. The experiment was conducted on two consecutive days. On the first day, the saline water was maintained at 0.5 cm depth, while on the next day, the saline water level was maintained at 1 cm. The cumulative yield for micro absorbent layer solar still (MALSS) was 3.23 kg/m 2 and nanoabsorbent layer solar still (NALSS) was 4.39 kg/m 2 .