Fabrication of Eco-Friendly Superabsorbent Composites Based on Waste Semicoke

Wei

Polymers and Polymer Composites

et al. 2023

In this work, novel superabsorbent composites made of starch-grafted-polyacrylic acid/coal gangue were prepared via aqueous solution polymerization. The starch-g-polyacrylic acid/coal gangue (St-g-PAA/CG) composite with 10 wt.% CG showed the maximum water absorbency in distilled water (560 g·g−1) and a 0.9 wt.% NaCl solution (102 g·g−1). Moreover, this superabsorbent composite exhibited fine thermal stability and its swelling behavior was dependent on pH. In general, the swelling kinetics of the superabsorbent composites fitted with the Scott’s kinetic model. These composites not only showed excellent water absorption reversibility after five absorption/drying cycles, but also exhibited considerable environmental responsiveness after the swelling medium was changed from distilled water to the 0.9 wt.% NaCl solution. Based on these results, the prepared superabsorbent composites can be applied in several fields such as horticulture, agriculture, health care, and controlled drug delivery, while ensuring comprehensive utilization of solid wastes.

Section: Water Absorbency Studiesmentioning

confidence: 69%

Fabrication and swelling properties of a novel superabsorbent composite derived from waste coal gangue

Wei

Polymers and Polymer Composites

et al. 2023

“…The polymeric structure of the novel superabsorbent was investigated using FTIR analysis (Figure 1). As showed in Figure 1 line a, the characteristic peaks at 1038, 787, 684, 529, 2924 and 2848 cm −1 all derived from the organic carbon and kaolinite of in OSSC [24,25]. Especially, the FTIR stretching peak at 1605 cm −1 was due to the bending vibration of hydroxyl or phenolic groups in the organic carbon of OSSC.…”

Section: Ftir Analysismentioning

confidence: 88%

Slow Release and Water Retention Performance of Poly(acrylic acid-co-acrylamide)/Fulvic Acid/Oil Shale Semicoke Superabsorbent Composites

et al. 2022

Self Cite

In order to achieve the low cost and multifunction of superabsorbent composites, poly(acrylic acid-co-acrylamide)/fulvic acid/oil shale semicoke (PAMFS) were prepared by free radical copolymerization of fulvic acid (FA), oil shale semicoke (OSSC), acrylic acid (AA) and acrylamide (AM). The characterization results revealed that FA and OSSC were involved in the construction of a three-dimensional (3D) polymeric network via hydrogen bonding and covalent bonding. The water absorbency of PAMFS in distilled water and 0.9 wt% NaCl solution were 724 and 98 g/g, respectively. The FA slow release of PAMFS in distilled water and soil was achieved due to the interaction between FA and the functional groups of polymer matrix by hydrogen bonds and covalent bonds. Furthermore, the potted experiment indicated that the addition of PAMFS to soil can significantly promote plant growth compared with the pure soil, regardless of water stress. Therefore, this superabsorbent composite showed an excellent water absorption and salt resistance performance, as well as nice slow release performance. It has a broad application prospect.

“…The composite amendments can effectively adjust the water content of copper tailings, which in the experimental area is 15.57%-16.16% after repairing with ryegrass, vetiver grass and tall fescue. The main reason is that the water retaining agent in the conditioner can effectively inhibit water evaporation, improve the saturated water content of copper tailings, weaken the saturated water conductivity of copper tailings, slow down the speed of water release from copper tailings, and thus reduce the in ltration and loss of copper tailings water (Wang et al 2020). In addition, the root system of herbs can reduce water and soil loss caused by surface runoff or wind erosion in an effective way, improve soil aggregate structure, and thus enhance the water retention capacity of copper tailings (Meisrimler et al 2015).…”

Section: Discussionmentioning

confidence: 99%

Effect of composite amendments on physicochemical properties of copper tailings repaired by herbaceous plants

Min

Xue

You

et al. 2022

Environ Sci Pollut Res

Phytoremediation is considered to be the most environmentally friendly green restoration technology for dealing with mine waste. Adding amendments can improve the substrate environment for plant growth and enhance remediation e ciency. Herbaceous plants have become the preferred species for vegetation restoration in abandoned mines because of their fast greening and simple management. Considering that, in this paper, to explore the effect of composite amendments on physicochemical properties of copper tailings repaired by herbaceous plants, the untreated copper tailings were employed as the control group, whereas copper tailings repaired by ryegrass (Lolium perenne L.), vetiver grass (Vetiveria zizanioides L.) and tall fescue (Festuca arundinacea Schreb) with or without conditioners and straw combination into the compound amendments, were taken separately as the test group. After 6 months of planting, the pH, electrical conductivity, water content, available potassium, organic matter, total nitrogen and available phosphorus in the main physical and chemical properties of copper tailings in each experimental area were analyzed. The results showed that the electrical conductivity, organic matter and total nitrogen content of copper tailings were improved to a certain extent by planting herbs without treatment. Meanwhile, compared with the control group, all indexes of planting herbs showed an upward trend after adding composite amendments. Among them, pH, water content and available potassium content of copper tailings were enhanced more obviously. Furthermore, as discovered from the grey correlation analysis results, vetiver grass planted with composite amendments has the best comprehensive effect of improving the physicochemical properties of copper tailings, followed by tall fescue and ryegrass.