scholarly journals Preparation of Poly (Allylthiourea-Co-Acrylic Acid) Derived Carbon Materials and Their Applications in Wastewater Treatment

Molecules ◽  
2019 ◽  
Vol 24 (5) ◽  
pp. 957 ◽  
Author(s):  
Limei Liang ◽  
Chengpeng Li ◽  
Tingting Hou ◽  
Zhiying Zhong ◽  
Dongchu Chen ◽  
...  

Functional carbon materials have been developed and applied in various sewage treatment applications in recent years. This article reports the fabrication, characterization, and application of a new kind of poly (allylthiourea-co-acrylic acid) (PAT–PAC) hydrogel-based carbon monolith. The results indicated that the poly acrylic acid component can endow the PAT–PAC hydrogel with an increased swelling ratio and enhanced thermal stability. During the carbonization process, O–H, N–H, C=N, and –COO– groups, etc. were found to be partly decomposed, leading to the conjugated C=C double bonds produced and the clear red shift of C=O bonds. Particularly, it was found that this shift was accelerated under higher carbonization temperature, which ultimately resulted in the complex conjugated C=C network with oxygen, nitrogen, and sulfur atoms doped in-situ. The as-obtained carbon monoliths showed good removal capacity for Ni(II) ions, organic solvents, and dyes, respectively. Further analysis indicated that the Ni(II) ion adsorption process could be well described by pseudo-second-order and Freundlich models under our experimental conditions, respectively. The adsorption capacity for Ni(II) ions and paraffin oil was as high as 557 mg/g and 1.75 g/g, respectively. More importantly, the as-obtained carbon monoliths can be recycled and reused for Ni(II) ions, acetone, and paraffin oil removal. In conclusion, the proposed PAT–PAC-based carbonaceous monoliths are superior adsorbents for wastewater treatment.

2017 ◽  
Vol 75 (6) ◽  
pp. 1500-1511 ◽  
Author(s):  
Shengjiong Yang ◽  
Pengkang Jin ◽  
Xiaochang C. Wang ◽  
Qionghua Zhang ◽  
Xiaotian Chen

In this study, a granular material (GM) developed from building waste was used for phosphate removal from phosphorus-containing wastewater. Batch experiments were executed to investigate the phosphate removal capacity of this material. The mechanism of removal proved to be a chemical precipitation process. The characteristics of the material and resulting precipitates, the kinetics of the precipitation and Ca2+ liberation processes, and the effects of dosage and pH were investigated. The phosphate precipitation and Ca2+ liberation processes were both well described by a pseudo-second-order kinetic model. A maximum precipitation capacity of 0.51 ± 0.06 mg g−1 and a liberation capacity of 6.79 ± 0.77 mg g−1 were measured under the experimental conditions. The processes reached equilibrium in 60 min. The initial solution pH strongly affected phosphate removal under extreme conditions (pH <4 and pH >10). The precipitates comprised hydroxyapatite and brushite. This novel GM can be considered a promising material for phosphate removal from wastewater.


e-Polymers ◽  
2015 ◽  
Vol 15 (4) ◽  
pp. 271-278 ◽  
Author(s):  
Jie Wu ◽  
Yanmei Zhou ◽  
Yang Meng ◽  
Jiaxing Zhang ◽  
Qingbing Liu ◽  
...  

AbstractA tough double-network (DN) superabsorbent was synthesized by a two-step method using N,N-methylenebisacrylamide as a covalent cross-linker for one monomer [acrylic acid (AA)], Ca2+ (CaCl2) as an ionic cross-linker for the other monomer (sodium alginate [SA]) and ammonium peroxodisulfate as the redox initiator. The optimized experimental conditions for the absorbency in deionized water were determined according to orthogonal experiments. Unlike conventional chemical cross-linked single-network superabsorbents, SA/poly(acrylic acid) (PAA) DN superabsorbents exhibit superb mechanical properties. Compared with the tensile strength of PAA-only superabsorbents, that of SA/PAA DN superabsorbents showed an approximately 371.9% increase with increasing amount of 6 wt.% SA. We also investigated the capacity of SA/PAA DN superabsorbents to remove heavy metal ions. It was found that the addition of SA can truly increase the metal ion removal capacity of the PAA superabsorbents and that the affinity order was Pb2+>Zn2+.


2012 ◽  
Vol 65 (8) ◽  
pp. 1383-1391 ◽  
Author(s):  
Y. F. He ◽  
L. Zhang ◽  
D. Z. Yan ◽  
S. L. Liu ◽  
H. Wang ◽  
...  

In this paper, a new kind of poly(acrylic acid) modified clay adsorbent, the poly(acrylic acid)/bentonite composite (PAA/HB) was prepared by in-situ polymerization, and utilized to remove lead(II) ions from solutions. The maximum adsorption of adsorbent is at pH 5 for metal ions, whereas the adsorption starts at pH 2. The effects of contact time (5–60 min), initial concentration of metal ions (200–1,000 mg/L) and adsorbent dosage (0.04–0.12 g/100 mL) have been reported in this article. The experimental data were investigated by means of kinetic and equilibrium adsorption isotherms. The kinetic data were analyzed by the pseudo-first-order and pseudo-second-order equation. The experimental data fitted the pseudo-second-order kinetic model very well. Langmuir and Freundlich isotherms were tried for the system to better understand the adsorption isotherm process. The maximal adsorption capacity of the lead(II) ions on the PAA/HB, as calculated from the Langmuir model, was 769.2 mg/g. The results in this study indicated that PAA/HB was an attractive candidate for removing lead(II) (99%).


2013 ◽  
Vol 11 (2) ◽  
pp. 205-217

In the present work, wood and bone ash were used to remove metal cations from solutions. Cation-removal capacity of the ashes was analyzed by potentiometric titration. It was found that the capacity of wood ash was two times higher (37.3 meq g-1) than bone ash (15.2 meq g-1). Kinetics of metal ions removal by both ashes was described with pseudo-second order equation and Langmuir model was employed to describe equilibrium of the process. Wood ash had better removal properties than bone ash - at the same experimental conditions biosorption capacity at equilibrium for wood ash was 2 times higher (244 mg g-1) than for bone ash (123 mg g-1). Promising results were also obtained for wood ash, which was capable of removing 67.9 % of Zn(II) ions, 70.4 % of Cd(II) ions, 92.8 % of Cu(II) ions and 99.1 % of Cr(III) ions from model solution of wastewater from metallurgical industry and 84.5 % of Cr(III) ions from the postbiosorption solution from the production process of biological feed additives. The utilization of ashes of biological origin was found to be a promising alternative to conventional processes of wastewater treatment.


Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1352
Author(s):  
Ikenna H. Ezenwajiaku ◽  
Emmanuel Samuel ◽  
Robin A. Hutchinson

The radical homopolymerization kinetics of 3-(methacryloylaminopropyl) trimethylammonium chloride (MAPTAC) and its batch copolymerization with nonionized acrylic acid (AA) in aqueous solution are investigated and modeled. The drift in monomer composition is measured during copolymerization by in situ NMR over a range of initial AA molar fractions and monomer weight fractions up to 0.35 at 50 °C. The copolymer becomes enriched in MAPTAC for monomer mixtures containing up to 60 mol% MAPTAC, but is enriched in AA for MAPTAC-rich mixtures; this azeotropic behavior is dependent on initial monomer content, as electrostatic interactions from the cationic charges influence the system reactivity ratios. Models for MAPTAC homopolymerization and AA-MAPTAC copolymerization are developed to represent the rates of monomer conversion and comonomer composition drifts over the complete range of experimental conditions.


2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.


1990 ◽  
Vol 22 (3-4) ◽  
pp. 65-72 ◽  
Author(s):  
H.-H. Schierup ◽  
H. Brix

Since 1983 approximately 150 full-scale emergent hydrophyte based wastewater treatment plants (reed beds) have been constructed in Denmark to serve small wastewater producers. The development of purification performance for 21 plants representing different soil types, vegetation, and hydraulic loading rates has been recorded. Cleaning efficiencies were typically in the range of 60-80% reduction for BOD, 25-50% reduction for total nitrogen, and 20-40% reduction for total phosphorus. The mean effluent BOD, total nitrogen and total phosphorus concentrations of the reed beds were 19 ± 10, 22 ± 9 and 6.7 ± 3.2 mg/l (mean ± SD), respectively. Thus, the general Danish effluent standards of 8 mg/l for N and 1.5 mg/l for P for sewage plants greater than 5,000 PE cannot be met by the present realised design of EHTS. The main problem observed in most systems is a poor development of horizontal hydraulic conductivity in the soil which results in surface run-off. Since the political demands for effluent quality will be more strict in the future, it is important to improve the performance of small decentral sewage treatment plants. On the basis of experiences from different types of macrophyte based and conventional low-technology wastewater treatment systems, a multi-stage system is suggested, consisting of sedimentation and sand filtration facilities followed by basins planted with emergent and submergent species of macrophytes and algal ponds.


Author(s):  
Huchuan Yan ◽  
Cui Lai ◽  
Dongbo Wang ◽  
Shiyu Liu ◽  
Xiaopei Li ◽  
...  

Refractory organic pollutants in wastewater have the characteristics of persistence and toxicity, which seriously threaten the health and safety of humans and other organisms. Many researchers have committed to developing...


Carbon ◽  
2021 ◽  
Vol 177 ◽  
pp. 428
Author(s):  
Xiaoqin Cheng ◽  
Huijun Li ◽  
Zhenxin Zhao ◽  
Yong-zhen Wang ◽  
Xiaomin Wang

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