Kaolin-Enhanced Superabsorbent Composites: Synthesis, Characterization and Swelling Behaviors

One type of low-cost and eco-friendly organic‒inorganic superabsorbent composite (SAPC) was synthesized by free radical polymerization of acrylic acid (AA), starch (ST), sodium alginate (SA) and kaolin (KL) in aqueous solution. The structure and morphology of the SAPC were characterized by Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The influence of different reaction conditions on water absorption of SAPC, i.e., SA and KL contents, AA neutralization degree (ND), potassium persulfate (KPS) and N, N′-methylenebisacrylamide (MBA) loading were systematically studied. Under the optimal synthesis conditions, very high water absorption of 1200 g/g was achieved. The swelling kinetic mechanism of SAPC was studied by pseudo-second order swelling kinetics model and Ritger‒Peppas model. The performances of SAPC under different environments were tested and results revealed that this new SAPC had excellent swelling capacity, high water retention, good salt tolerance in monovalent salt solution (NaCl solution) and good pH tolerance between 4 and 10.

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Poly(sodium methacrylate)/eggshell particles hydrogel composites as dye sorbent

Water Science & Technology ◽

10.2166/wst.2016.453 ◽

2016 ◽

Vol 74 (12) ◽

pp. 2807-2818 ◽

Cited By ~ 3

Author(s):

Atefeh Darvishi ◽

Hadi Bakhshi

Keyword(s):

Water Absorption ◽

Low Cost ◽

Dye Adsorption ◽

Cost Effective ◽

Absorption Capacity ◽

Rate Limiting Step ◽

Pseudo Second Order ◽

Hydrogel Composites ◽

Phosphate Buffered Saline ◽

Sodium Methacrylate

Eggshell (ES) particles as an available and low-cost waste material were utilized to prepare novel hydrogel composites for dye adsorbing application. For this purpose, solution polymerization of sodium methacrylate was carried out in the presence of ES particles with various size ranges. Results showed that incorporation of ES particles resulted in heterogeneous pores and cavities in the structure of the poly(sodium methacrylate) (PNaMA) matrix. Hydrogel composites with lower content (20 wt%) and smaller size (<75 μm) of ES particles presented higher water absorption capacity. The equilibrium water absorption values in distilled water were higher than phosphate buffered saline medium. ES particles showed low methylene blue (MB) and crystal violet (CV) adsorption capacities due to electrostatic repulsion of the positively charged species on the surface of ES particles and dye molecules. In contrast, hydrogel composites depicted fast and considerable dye adsorbability. The combination of 60 wt% ES particles within PNaMA provided a cost-effective adsorbent with similar CV adsorption capacity compared with the unfilled matrix, while MB removal was slightly decreased. The dye adsorption by either ES particles or hydrogel composites followed the pseudo-second-order kinetics, indicating that chemical sorption is the rate-limiting step for both of them.

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Silylated-montmorillonite as co-adsorbent of chitosan composites for methylene blue dye removal in aqueous solution

Communications in Science and Technology ◽

10.21924/cst.5.1.2020.182 ◽

2020 ◽

Vol 5 (1) ◽

pp. 45-52

Author(s):

Ozi Adi Saputra ◽

Kurnia ◽

Septi Pujiasih ◽

Vanani Nur Rizki ◽

Betty Nurhayati ◽

...

Keyword(s):

Methylene Blue ◽

Dye Removal ◽

Negative Impact ◽

Low Cost ◽

Kinetic Mechanism ◽

Precipitation Method ◽

Blue Dye ◽

Methylene Blue Dye ◽

Pseudo Second Order ◽

Mapping Techniques

Industrialization plays important role in the economy of developing countries, including increasing community welfare. However, the presence of poorly industries waste disposal system has negative impact to the environment. Therefore, it is necessary to overcome this problem with low-cost technology, called adsorption. In this research, silylated-montmorillonite (sMMt) has been successfully prepared as supporting material for adsorption of methylene blue by chitosan. The sMMt was characterized by FTIR, XRD, and elemental mapping techniques. The chitosan/sMMt composites were prepared through dissolution-precipitation method and produced rod-like morphology as observed by SEM. The adsorption process was carried out in a batch method by studying the pH and the adsorption contact time. The adsorption kinetic mechanism of the chitosan/sMMt nanocomposite followed pseudo-second order rather than Lagergren model indicating chemisorption predominant. The addition of silylated-montmorillonite into chitosan enhanced the methylene blue dye removal performance, which evidenced by improving Qe values by 10% compared to chitosan.

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Surface interaction of sweet potato peels (Ipomoea batata) with Cd(II) and Pb(II) ions in aqueous medium

10.31221/osf.io/gfdht ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Aqueous Medium ◽

Sweet Potato ◽

Adsorption Process ◽

Low Cost ◽

Correlation Coefficients ◽

Order Kinetic ◽

Thermodynamic Evaluation ◽

Dissociative Mechanism ◽

Pseudo Second Order ◽

Potato Peels

The removal of Cd(II) and Pb(II) ions from aqueous medium was studied using potato peels biomass. The adsorption process was evaluated using Atomic Absorption Spectrophotometer (AAS). The Vibrational band of the potato peels was studied using Fourier Transform Infrared Spectroscopy (FTIR). The adsorption process was carried out with respect to concentration, time, pH, particle size and the thermodynamic evaluation of the process was carried at temperatures of 30, 40, 50 and 60(0C), respectively. The FTIR studies revealed that the potato peels was composed of –OH, -NH, –C=N, –C=C and –C-O-C functional groups. The optimum removal was obtained at pH 8 and contact time of 20 min. The adsorption process followed Freundlich adsorption and pseudo second-order kinetic models with correlation coefficients (R2) greater than 0.900. The equilibrium adsorption capacity showed that Pb(II) ion was more adsorbed on the surface of the potato peels biomass versus Cd (II) ion (200.91 mg/g > 125.00 mg/g). The thermodynamic studies indicated endothermic, dissociative mechanism and spontaneous adsorption process. This study shows that sweet potato peels is useful as a low-cost adsorbent for the removal of Cd(II) and Pb(II) ions from aqueous medium.

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Competitive Biosorption of Pb(II) and Cu(II) by Functionalised Micropogonias undulates Scales

Recent Innovations in Chemical Engineering (Formerly Recent Patents on Chemical Engineering) ◽

10.2174/2405520413999200623174612 ◽

2020 ◽

Vol 13 ◽

Author(s):

Joshua O. Ighalo ◽

Ibrahim O. Tijani ◽

Oluwaseun J. Ajala ◽

Fisayo O. Ayandele ◽

Omodele A. Eletta ◽

...

Keyword(s):

Adsorption Capacity ◽

Low Cost ◽

Fish Scales ◽

Wet Impregnation ◽

Monolayer Adsorption ◽

Competitive Biosorption ◽

Langmuir Isotherm Model ◽

Pseudo Second Order ◽

Ft Ir ◽

Best Fit

Background: Modified bio-based adsorbents from plant sources can be used for pollution remediation by adsorption due to their low cost and availability in large quantities. Objective: In this study, the competitive biosorption of Pb(II) and Cu(II) by Micropogonias undulates functionalised fish scales (FFS) was conducted. The functionalisation was done by wet impregnation with Fe2+. Method: The biosorbent was characterised by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopy (SEM-EDS) and Branueur–Emmett–Teller (BET) analyses. Results: The major constituents in the FFS were calcium and phosphorus from the collagen and apatite on the scales. Optimum removal efficiency for both metals was >99% at 10 g/l dosage. It was observed that the Langmuir isotherm model and the pseudo second order kinetics model were the best fit for the experimental data. The monolayer adsorption capacity of FFS for Pb(II) and Cu(II) was observed to be 96.15 mg/g and 100 mg/g respectively. Conclusion: The study revealed that the competitive biosorption of heavy metals can be achieved (at a good adsorption capacity) using functionalised Micropogonias undulates fish scales.

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Treadle pump: A low cost irrigation option for marginal farmers

Journal of AgriSearch ◽

10.21921/jas.5.3.10 ◽

2018 ◽

Vol 5 (03) ◽

Author(s):

ATIQUR RAHMAN ◽

ASHUTOSH UPADHYAYA ◽

BP BHATT

Keyword(s):

Low Cost ◽

Water Productivity ◽

High Water ◽

Water Saving ◽

Age Group ◽

Male And Female ◽

Human Power ◽

Dry Spells ◽

Supplementary Irrigation ◽

Land Holdings

The population of marginal farmers in India is bound to increase due to continued division of farm holdings. Characteristically, marginal farmers are having more family labours but the production and productivity of their land holdings is low. The foremost reason behind this is the erratic rainfall and lack of assure supplementary irrigation during long dry spells. This paper presents the scope and applicability of a diaphragm based treadle pump in Bihar where groundwater is abundant and available at shallow depths round the year. Therefore, this pump could be very useful for marginal farmers in improving production and productivity of their tiny piece of land, as it uses human power and can be operated by male and female of age group 32- 45 years and lifts water from a depth ranging from 0- 30 feet. The water saving technologies such as bucket kit drum kit etc. could be used with this pump to irrigate the crops with high water productivity.

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Physical and mechanical properties of rubberwood (Hevea brasiliensis) dyed with Lasiodiplodia theobromae

Journal of Wood Science ◽

10.1186/s10086-019-1843-z ◽

2019 ◽

Vol 65 (1) ◽

Cited By ~ 2

Author(s):

Boshi Zhao ◽

Zhiming Yu ◽

Yang Zhang ◽

Chusheng Qi

Keyword(s):

Mass Loss ◽

Water Absorption ◽

Hevea Brasiliensis ◽

Ph Value ◽

Energy Dispersive Spectrometer ◽

Physical And Mechanical Properties ◽

Blue Staining ◽

Loss Ratio ◽

Lasiodiplodia Theobromae ◽

Infrared Spectrometer

AbstractBlue staining on rubberwood (Hevea brasiliensis) is a common kind of defect. There currently exists much research focused on the prevention and control of blue staining. However, little research has been concentrated on the utilization of blue staining for green dyeing. The research conveyed in this paper primarily used Lasiodiplodia theobromae to dye rubberwood, and used scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), X-ray diffraction (XRD), and fourier transform infrared spectrometer (FTIR) to analyze the commission internationale eclairage (CIE) L*a*b* value of color, the contact angle, the pH value, 24-h water absorption, mass loss ratio, and compressive strength in increments between 5 and 40 days. The results found that the color of rubberwood became darker and more uniform, and that the surface dyed with fungi can reach a super-hydrophobic state. With the increase of time, the pH value of rubberwood changed from acidic to alkaline. Furthermore, hyphae entered the wood mainly through vessels for their large pore diameter, and reduced water absorption. Mass loss ratio increased gradually between 5 and 40 days. The research in this paper concludes that the microorganism was an effective method of wood dyeing, and lays a foundation for further research.

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Kinetics and isotherm modeling of Pb(II) and Cd(II) sequestration from polluted water onto tropical ultisol obtained from Enugu Nigeria

Applied Water Science ◽

10.1007/s13201-021-01402-8 ◽

2021 ◽

Vol 11 (4) ◽

Author(s):

Theresa C. Umeh ◽

John K. Nduka ◽

Kovo G. Akpomie

Keyword(s):

Metal Ions ◽

Low Cost ◽

Water Environment ◽

Standard Technique ◽

Soil Surface ◽

Cost Effective ◽

Polluted Water ◽

Batch Adsorption ◽

Lead And Cadmium ◽

Pseudo Second Order

AbstractDeterioration in soil–water environment severely contributed by heavy metal bioavailability and mobility on soil surface and sub-surface due to irrational increase in wastewater discharge and agrochemical activities. Therefore, the feasibility of adsorption characteristics of the soil is paramount in curbing the problem of micropollutant contamination in the farming vicinity. Soil from a farming site in a populated area in Enugu, Nigeria was collected and tested to measure the lead and cadmium contents using atomic absorption spectrophotometer (AAS). The adsorption potency of the ultisol soil was estimated for identifiable physicochemical properties by standard technique. The mean activity concentration of Pb2+ and Cd2+ was 15.68 mg/kg and 3.01 mg/kg. The pH, temperature, metal concentration and contact time adsorptive effect on the Pb2+ and Cd2+ uptake was evaluated by batch adsorption technique. The Langmuir, Freundlich and Temkin models were fitted into equilibrium adsorption data and the calculated results depict a better and satisfactory correlation for Langmuir with higher linear regression coefficients (Pb2+, 0.935 and Cd2+, 0.971). On the basis of sorption capacity mechanism of the soil, pseudo-second-order model best described the kinetics of both metal ions retention process. The results of the present study indicated that the soil being a low cost-effective adsorbent can be utilized to minimize the environmental risk impact of these metal ions.

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Reinforcement of Recycled Aggregate by Microbial-Induced Mineralization and Deposition of Calcium Carbonate—Influencing Factors, Mechanism and Effect of Reinforcement

Crystals ◽

10.3390/cryst11080887 ◽

2021 ◽

Vol 11 (8) ◽

pp. 887

Author(s):

Chunhua Feng ◽

Buwen Cui ◽

Haidong Ge ◽

Yihong Huang ◽

Wenyan Zhang ◽

...

Keyword(s):

Calcium Carbonate ◽

Global Economy ◽

Low Cost ◽

High Water ◽

Strengthening Mechanism ◽

Recycled Aggregate ◽

Strengthening Effect ◽

Calcium Carbonate Precipitation ◽

Environmental Friendliness ◽

Advantages And Disadvantages

Recycled aggregate is aggregate prepared from construction waste. With the development of a global economy and people’s attention to sustainable development, recycled aggregate has shown advantages in replacing natural aggregate in the production of concrete due to its environmental friendliness, low energy consumption, and low cost. Recycled aggregate exhibits high water absorption and a multi-interface transition zone, which limits its application scope. Researchers have used various methods to improve the properties of recycled aggregate, such as microbially induced calcium carbonate precipitation (MICP) technology. In this paper, the results of recent studies on the reinforcement of recycled aggregate by MICP technology are synthesized, and the factors affecting the strengthening effect of recycled aggregate are reviewed. Moreover, the strengthening mechanism, advantages and disadvantages of MICP technology are summarized. After the modified treatment, the aggregate performance is significantly improved. Regardless of whether the aggregate was used in mortar or concrete, the mechanical properties of the specimens were clearly improved. However, there are some issues regarding the application of MICP technology, such as the use of an expensive culture medium, a long modification cycle, and untargeted mineralization deposition. These difficulties need to be overcome in the future for the industrialization of regenerated aggregate materials via MICP technology.

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Cellulose Nanofibrils/Xyloglucan Bio-Based Aerogels with Shape Recovery

Gels ◽

10.3390/gels7010005 ◽

2021 ◽

Vol 7 (1) ◽

pp. 5

Author(s):

Samuel Mandin ◽

Samuel Moreau ◽

Malika Talantikite ◽

Bruno Novalès ◽

Jean-Eudes Maigret ◽

...

Keyword(s):

Water Absorption ◽

Shape Recovery ◽

Cellulose Nanofibrils ◽

High Water ◽

Absorption Capacity ◽

Absorption Properties ◽

High Affinity ◽

High Water Absorption ◽

Freezing Procedure ◽

The Impact

Bio-based aerogels containing cellulose nanofibrils (CNFs) are promising materials due to the inherent physical properties of CNF. The high affinity of cellulose to plant hemicelluloses (xyloglucan, xylan, pectin) is also an opportunity to develop biomaterials with new properties. Here, we prepared aerogels from gelled dispersions of CNFs and xyloglucan (XG) at different ratios by using a freeze-casting procedure in unidirectional (UD) and non-directional (ND) manners. As showed by rheology analysis, CNF and CNF/XG dispersions behave as true gels. We investigated the impact of the freezing procedure and the gel’s composition on the microstructure and the water absorption properties. The introduction of XG greatly affects the microstructure of the aerogel from lamellar to cellular morphology. Bio-based aerogels showed high water absorption capacity with shape recovery after compression. The relation between morphology and aerogel compositions is discussed.

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Properties of Low-Cost WPCs Made from Alien Invasive Trees and rLDPE for Interior Use in Social Housing

Polymers ◽

10.3390/polym13152436 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2436

Author(s):

Abubakar Sadiq Mohammed ◽

Martina Meincken

Keyword(s):

Tensile Strength ◽

Water Absorption ◽

Social Housing ◽

Low Cost ◽

Production Costs ◽

Low Density Polyethylene ◽

Low Grade ◽

Low Density ◽

Invasive Trees ◽

Recycled Low Density Polyethylene

Low-cost wood–plastic composites (WPCs) were developed from invasive trees and recycled low-density polyethylene. The aim was to produce affordable building materials for low-cost social housing in South Africa. Both raw materials are regarded as waste materials, and the subsequent product development adds value to the resources, while simultaneously reducing the waste stream. The production costs were minimised by utilising the entire biomass of Acacia saligna salvaged from clearing operations without any prior processing, and low-grade recycled low-density polyethylene to make WPCs without any additives. Different biomass/plastic ratios, particle sizes, and press settings were evaluated to determine the optimum processing parameters to obtain WPCs with adequate properties. The water absorption, dimensional stability, modulus of rupture, modulus of elasticity, tensile strength, and tensile moduli were improved at longer press times and higher temperatures for all blending ratios. This has been attributed to the crystallisation of the lignocellulose and thermally induced cross-linking in the polyethylene. An increased biomass ratio and particle size were positively correlated with water absorption and thickness swelling and inversely related with MOR, tensile strength, and density due to an incomplete encapsulation of the biomass by the plastic matrix. This study demonstrates the feasibility of utilising low-grade recycled polyethylene and the whole-tree biomass of A. saligna, without the need for pre-processing and the addition of expensive modifiers, to produce WPCs with properties that satisfy the minimum requirements for interior cladding or ceiling material.

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