Search

Abstract Wastewater contaminated with cadmium is a concern because of its toxicity, persistence, and bioaccumulation to the environment, ecosystem, and human health, so it is required to remove cadmium(II) ions before releasing them to receiving water. Banana powder beads (BPB), banana powder doped ZnO beads (BPZB), banana powder doped MgO beads (BPMB), and banana powder doped ZnO + MgO beads (BPZMB) were synthesized as the novel cadmium adsorbents, and their characterizations, cadmium adsorption performances, cadmium adsorption patterns and mechanisms, thermodynamic study, and reusability were investigated. BPMB had the highest specific surface area of 16.60 m2/g and the smallest pore size of 1.69 nm than other materials. BPB was an amorphous structure, whereas BPZB, BPMB, and BPZMB were crystalline structures presenting their specific metal oxide peaks of ZnO or MgO. They were coarse surfaces and had a spherical shape consisting of C, O, Ca, Cl, and Na. Their main functional groups were O–H, C–H, C=O, C–O, and N–H. The points of zero charge of BPB, BPZB, BPMB, and BPZMB were 5.37, 6.75, 9.87, and 9.43. The cadmium removal efficiencies of BPB, BPZB, BPMB, and BPZMB were 89.18%, 96.62%, 99.59%, and 97.85%, and their q m values were 90.09, 232.56, 454.55, and 303.03 mg/g, respectively. Thus, the metal oxide helped to improve material efficiency, especially MgO. The Freundlich and pseudo-second-order kinetic models were good fit models for describing their adsorption patterns and mechanisms. The increasing temperature affected to decrease their cadmium adsorptions. They could be reused in more than 3 cycles of more than 73% of cadmium adsorption. The electrostatic interaction played an important role in describing their cadmium adsorptions. Therefore, BPBM was a good cadmium adsorbent for application in industrial wastewater treatment since it had a higher performance of cadmium adsorption than other materials.

Abstract The pomelo-doped zinc oxide beads (PZB), pomelo-doped titanium dioxide beads (PTB), and pomelo-doped zinc oxide and titanium dioxide beads (PZTB) were synthesized for sorbing methylene blue (MB) dye. Their characterizations were explored by X-Ray Diffractometer (XRD), Field Emission Scanning Electron Microscopy and Focus Ion Beam (FESEM-FIB), Energy Dispersive X-Ray Spectrometer (EDX), and Fourier Transform Infrared Spectroscopy (FT-IR). In addition, their sorbent efficiencies for sorbing MB dye were investigated through batch experiments, sorbent reusability studies, sorption isotherms, kinetics, and thermodynamic studies. They were crystalline phases presenting the specific peaks of zinc oxide (ZnO) or titanium dioxide (TiO2). Their surfaces had lamella structures with coarse surfaces, and they also found specific structures of ZnO or TiO2 on the surfaces. Zn–O or Ti–O–Ti was also detected in PZB or PTB or, PZTB depending upon metal oxide types added into pomelo beaded sorbents. For batch experiments, they could adsorb MB dye of more than 86%, and PZTB showed the highest MB dye removal efficiency. In addition, they could be reused for more than three cycles with high MB dye sorptions of more than 72%. They corresponded to Freundlich and pseudo-second-order kinetic models. Moreover, the increasing temperature affected their decreasing MB dye sorptions which were exothermic processes.

Abstract The direct red 28 (DR28) dye contamination in wastewater blocks the transmission of light into the water body resulting in the inability to photosynthesize by aquatic life. In addition, it is difficult to break down and persist in the environment, and it is also harmful to aquatic life and water quality because of its aromatic structure. Thus, wastewater contaminated with dyes is required to treat before releasing into the water body. Sugarcane bagasse beads (SBB), sugarcane bagasse modified with titanium dioxide beads (SBBT), sugarcane bagasse modified with magnesium oxide beads (SBBM), sugarcane bagasse modified with aluminum oxide beads (SBBA), and sugarcane bagasse modified with zinc oxide beads (SBBZ) for DR28 dye removal in aqueous solution, and they were characterized with several techniques of BET, FESEM-FIB, EDX, FT-IR, and the point of zero charges (pHpzc). Their DR28 dye removal efficiencies were examined through batch tests, adsorption isotherms, and kinetics. SBBM had the highest specific surface area and pore volume, whereas its pore size was the smallest among other materials. The surfaces of SBB, SBBM, SBBT, and SBBA were scaly sheet surfaces with an irregular shape, whereas SBBZ was a coarse surface. Oxygen, carbon, calcium, chloride, sodium, O–H, C–H, C=O, C=C, and C–O–C were found in all materials. The pHpzc of SBB, SBBT, SBBM, SBBA, and SBBZ were 6.57, 7.31, 10.11, 7.25, and 7.77. All materials could adsorb DR28 dye at 50 mg/L by more than 81%, and SBBM had the highest DR28 dye removal efficiency of 94.27%. Langmuir model was an appropriate model for SBB, whereas Freundlich model was a suitable model for other materials. A pseudo-second-order kinetic model well described their adsorption mechanisms. Their adsorptions of the DR28 dye were endothermic and spontaneous. Therefore, they were potential materials for adsorbing DR28 dye, especially SBBM.

Abstract Lead-contaminated wastewater causes toxicity to aquatic life and water quality for water consumption, so it is required to treat wastewater to be below the water quality standard before releasing it into the environment. Duck eggshell powder (DP), duck eggshell powder mixed iron (III) oxide-hydroxide (DPF), calcinated duck eggshell powder (CDP), and calcinated duck eggshell powder mixed iron (III) oxide-hydroxide (CDPF) were synthesized, characterized, and investigated lead removal efficiencies by batch experiments, adsorption isotherms, kinetics, and desorption experiments. CDPF demonstrated the highest specific surface area and pore volume with the smallest pore size than other materials, and they were classified as mesoporous materials. DP and DPF demonstrated semi-crystalline structures with specific calcium carbonate peaks, whereas CDP and CDPF illustrated semi-crystalline structures with specific calcium oxide peaks. In addition, the specific iron (III) oxide-hydroxide peaks were detected in only DPF and CDPF. Their surface structures were rough with irregular shapes. All materials found carbon, oxygen, and calcium, whereas iron, sodium, and chloride were only found in DPF and CDPF. All materials were detected O–H, C=O, and C–O, and DPF and CDPF were also found Fe–O from adding iron (III) oxide-hydroxide. The point of zero charges of DP, DPF, CDP, and CDPF were 4.58, 5.31, 5.96, and 6.75. They could adsorb lead by more than 98%, and CDPF illustrated the highest lead removal efficiency. DP and CDP corresponded to the Langmuir model while DPF and CDPF corresponded to the Freundlich model. All materials corresponded to a pseudo-second-order kinetic model. Moreover, they could be reusable for more than 5 cycles for lead adsorption of more than 73%. Therefore, CDPF was a potential material to apply for lead removal in industrial applications.

Abstract Lead contamination in wastewater causes toxicity to aquatic life, the environment, and water quality, and it causes many human dysfunctions and diseases. Thus, it is necessary to remove lead from wastewater before discharging it into the environment. Orange peel powder (OP) and orange peel powder doped iron (III) oxide-hydroxide (OPF) were synthesized, characterized, and investigated lead removal efficiencies by batch experiments, adsorption isotherms, kinetics, and desorption experiments. The specific surface area of OP and OPF were 0.431 and 0.896 m2/g, and their pore sizes were 4.462 and 2.575 nm, respectively which OPF had a higher surface area than OP, whereas its pore size was smaller than OP. They were semi-crystalline structures that presented the specific cellulose peaks, and OPF also detected the specific iron (III) oxide-hydroxide peaks. The surface morphologies of OP and OPF were irregular and porous surfaces. Carbon (C), oxygen (O), calcium (Ca), O–H, C–H, C=C, C–O, C=O, and –COOH were observed in both materials. The pHpzc of OP and OPF were 3.74 and 4.46. For batch experiments, OPF demonstrated a higher lead removal efficiency than OP because of spending less on material dosage than OP, and OPF demonstrated high lead removal by more than 95% while OP could remove lead at only 67%. Thus, the addition of iron (III) oxide-hydroxide helped to increase material efficiency for lead adsorption. Both materials corresponded to the Freundlich model relating to physiochemical adsorption, and they also corresponded to a pseudo-second-order kinetic model relating to a chemisorption process. Moreover, both materials could be reusable for more than 5 cycles for lead adsorption of more than 55%. Therefore, OPF was potential material to apply for lead removals in industrial applications.

The releasing of wastewater contaminated with direct red 28 (DR28) dye into receiving water is a concern because it is a polyaromatic structure with difficult biodegradation. It results in being persistent in the environment and being toxic to the ecosystem from accumulating through a food chain. Thus, it needs to eliminate DR28 dye from contaminated wastewater. Sawdust beads (SDB) and sawdust mixed with iron(III) oxide-hydroxide beads (SDFB) are prepared and characterized for DR28 dye removals. DR28 dye removal efficiencies are examined with various affecting factors by the batch tests and adsorption–desorption tests, and their adsorption patterns, rates, and mechanisms are determined by isotherms and kinetics models. Moreover, the thermodynamic studies are examined for the temperature effect. SDFB demonstrated a higher surface area and smaller pore size than SDB. SDB and SDFB were uneven shapes and heterogeneous fibrillar structures. Carbon, oxygen, calcium, chloride, sodium, OH, CH, CC, COOH, and CO were found in SDB and SDFB. The points of zero charge of SDB and SDFB were 4.65 and 6.11. The conditions of 3.5 g, 50 ℃, pH 3, 60 mg/L and 2.5 g, 40 ℃, pH 3, 60 mg/L illustrated the highest DR28 dye removals of more than 82 % for SDB and SDFB, respectively. Thus, the material modification by iron(III) oxide-hydroxide improved the DR28 dye removal efficiency of sawdust material. Moreover, they could be reusability more than three times with DR28 dye removal of more than 63 %. SDB and SDFB corresponded to Langmuir and Freundlich models, respectively, and a pseudo-second-order was a good model to describe their adsorption mechanism. Both materials did not favor DR28 dye adsorptions with increasing temperature. Therefore, SDFB was a potential material for removing DR28 dye removal in the industrial wastewater.

Abstract The discharging of lead-contaminated wastewater is a concern because of its toxicity to living organisms and water quality resulting in dangerous water consumption, so it is highly recommended to remove lead from wastewater to be below water quality standards for a safe environment. Zeolite A sugarcane bagasse fly ash powder (ZB), zeolite A sugarcane bagasse fly ash powder mixed iron(III) oxide-hydroxide (ZBF), zeolite A sugarcane bagasse fly ash beads (ZBB), zeolite A sugarcane bagasse fly ash powder mixed iron(III) oxide-hydroxide beads (ZBFB), and zeolite A sugarcane bagasse fly ash beads coated iron(III) oxide-hydroxide (ZBBF) were synthesized and characterized in various techniques. Their lead removal efficiencies were investigated by batch experiments, adsorption isotherms, and kinetics. The specific surface area, pore volume, and pore size of ZB were close values to zeolite A standard (STD), and ZBF had the highest specific surface area and the smallest pore size than others. ZB and ZBF demonstrated crystalline phases whereas ZBB, ZBFB, and ZBBF were amorphous phases. The surface morphology of ZB was a cubic shape similar to STD. ZBF demonstrated an agglomerated formation of ZB and iron(III) oxide-hydroxide whereas ZBFB and ZBBF had sphere shapes with coarse surfaces. Si, Al, O, Fe, Na, Ca, O–H, (Si, Al)–O, H2O, and D4R were detected in all materials. The surface charges of all zeolite A materials had negatively charged at all pH values, and their surfaces increased more negatively charged with increasing pH value which pH 5 illustrated as the highest negatively charged in all materials. Their lead removal efficiencies were higher than 82%. Langmuir isotherm and pseudo-second-order kinetic models were well explained for their adsorption patterns and mechanisms. Finally, ZBBF is a good offer for applying in industrial wastewater treatment systems because of its easy operation and saving costs than ZBF.

Abstract Lead contamination in wastewater results in toxicity of aquatic life and water quality, it is recommended to remove lead before discharging. Four sugarcane bagasse adsorbent materials of sugarcane bagasse powder (SB), sugarcane bagasse powder doped iron(III) oxide-hydroxide (SBF), sugarcane bagasse powder beads (SBB), and sugarcane bagasse powder doped iron(III) oxide-hydroxide beads (SBFB) were synthesized and characterized with various techniques. Their lead removal efficiencies were investigated by batch experiments on the effects of dose (0.1–0.6 g), contact time (1–6 h), pH (1, 3, 5, 7, 9, 11), and concentration (5–30 mg/L), adsorption isotherms, kinetics, and desorption experiments. All materials were amorphous phases presenting specific peaks of cellulose. SBB and SBFB detected sodium alginate peaks, and iron(III) oxide-hydroxide peaks were detected in SBF and SBFB. SB and SBF were scales or overlapping plate surfaces whereas SBB and SBFB had spherical shapes with coarse surfaces. The main functional groups of O–H, C=O, C–H, C–O, and C=C were observed in all materials, whereas Fe–O and –COOH were only found in materials with adding iron(III) oxide-hydroxide or bead material. The point of zero charges (pHpzc) of all materials was higher than 4. The optimum conditions of SB, SBF, SBB, and SBFB with the highest lead removal efficiency at a lead concentration of 10 mg/L and pH 5 were 0.6 g and 6 h (96.08%), 0.2 g and 3 h (100%), 0.2 g and 2 h (98.22%), and 0. 1 g and 2 h (100%), respectively. Since SBFB spent less adsorbent dose and contact time than other materials with a lead removal efficiency of 100%, it was a more potential adsorbent than other materials. Thus, adding iron(III) oxide-hydroxide and changing material form helped to improve material efficiencies for lead adsorption. The maximum adsorption capacities of SB, SBF, SBB, and SBFB were 6.161, 27.027, 23.697, and 57.471 mg/L, respectively by fitting the Langmuir model. Langmuir isotherm was best fitted for SB and SBB, whereas the Freundlich model was best fitted for SBF and SBFB. The pseudo-second-order kinetic model was best fitted for all materials. Moreover, all adsorbents could be reused for more than 5 cycles with the lead removal efficiency of more than 73%. Therefore, SBFB was potential material to further apply for lead removal in industrial applications.

Abstract The problems of lead and reactive blue 4 (RB4) dye contamination in wastewater are concerns because of their toxicities to aquatic life and water quality, so lead and RB4 dye removals are recommended to remove from wastewater before discharging. Sawdust powder (SP), sawdust powder doped iron (III) oxide-hydroxide (SPF), sawdust beads (SPB), and sawdust powder doped iron (III) oxide-hydroxide beads (SPFB) were synthesized and characterized with various techniques, and their lead or RB4 dye removal efficiencies were investigated by batch experiments, adsorption isotherms, kinetics, and desorption experiments. SPFB demonstrated higher specific surface area (11.020 m2 g−1) and smaller pore size (3.937 nm) than other materials. SP and SPF were irregular shapes with heterogeneous structures whereas SPB and SPFB had spherical shapes with coarse surfaces. Calcium (Ca) and oxygen (O) were found in all materials whereas iron (Fe) was only found in SPF and SPFB. O–H, C–H, C=C, and C–O were detected in all materials. Their lead removal efficiencies of all materials were higher than 82%, and RB4 dye removal efficiencies of SPB and SPFB were higher than 87%. Therefore, adding iron (III) oxide-hydroxide and changing material form helped to improve material efficiencies for lead or RB4 dye adsorption. SP and SPB corresponded to Langmuir model related to a physical adsorption process whereas SPF and SPFB corresponded to the Freundlich model correlated to a chemisorption process. All materials corresponded to a pseudo-second-order kinetic model relating to the chemical adsorption process. All materials could be reused more than 5 cycles with high lead removal of 63%, and SPB and SPFB also could be reused more than 5 cycles for high RB4 dye removal of 72%. Therefore, SPFB was a potential material to apply for lead or RB4 dye removal in industrial applications.

Abstract Lead contamination in wastewater may affect aquatic organisms, the environment, and human consumption because it is a highly toxic metal that caused human health effects. Thus, it is recommended to remove lead before releasing it into the environment. Powdered and beaded chitosan materials modified with ZnO were synthesized and investigated by various characterized techniques. Lead removal efficiencies of chitosan materials were studied by batch experiments, adsorption isotherms, and kinetics. Chitosan powder (CP), chitosan beads (CB), chitosan beads mixed ZnO (CZB), and chitosan beads coated ZnO (ZCB) were synthesized. CP represented a semi-crystalline structure while CB was an amorphous structure. CZB and ZCB were semi-crystalline structures with ZnO peaks. CP was a scaly-sheet and coarse surface while CB, CZB, and ZCB were sphere shapes with scaly-sheet surfaces. C, O, and N were the main chemical elements in chitosan materials, and Zn was detected in CZB and ZCB. O–H, N–H, and C–O were the main functional groups of chitosan materials. All chitosan materials had high lead removal efficiencies of more than 92%, and Freundlich and pseudo-second-order kinetic models well explained their adsorption patterns and mechanisms. Therefore, both adding metal oxide and changing material form are recommended for improving material efficiency, and ZCB was a good offer for further industrial applications.

The contamination of lead in wastewater causes water quality problems, which is toxic to aquatic organisms and environment, so wastewater treatment is required before discharging to receiving water. Chicken eggshell powder (CP) and chicken eggshell powder-doped iron (III) oxide-hydroxide (CPF) were synthesized, characterized, and investigated lead removal efficiencies by batch experiments, adsorption isotherms, kinetics, and desorption experiments. The specific surface area and pore volume of CPF were higher than CP, whereas the pore diameter size of CPF was smaller than CP. The phase structures of both materials demonstrated semi-crystalline phases with presenting peaks of calcium carbonate. Their surface morphologies were irregular, rough, and uneven surfaces. In both materials, they detected carbon, calcium, oxygen, OH, NH, CO, CO, and CH. The point of zero charges (pHpzc) of CP and CPF were 4.47 and 4.83. For batch experiments, CPF demonstrated a higher lead removal efficiency than CP because of spending less material dosage and contact time than CP, and both materials had high lead removals at a lead concentration of 50 mg/L by more than 95 %. Thus, the addition of iron (III) oxide-hydroxide helped to increase material efficiency for lead adsorption. CP corresponded to the Langmuir model while CPF corresponded to the Freundlich model. In addition, both materials corresponded to a pseudo-second-order kinetic model relating to a chemisorption process. Moreover, both materials could be reusable for more than 5 cycles for lead adsorption of more than 77 %. Therefore, CPF was a potential material to apply for lead removals in industrial applications.

Using extracted plants is an attractive option because they consist of good chemical properties against different types of bacteria, and the idea of a form modification in beads may conveniently apply to the disinfection of wastewater systems. Garcinia cowa and Piper sarmentosum leaves were extracted for the synthesis of bead materials and studied material characterizations. A disc diffusion assay, batch experiments, adsorption isotherms, adsorption kinetics, and desorption experiments were studied for investigating the bacteria removal efficiencies of materials. G. cowa and P. sarmentosum leaves were prepared in powder (GCP and PSP), ethanol extracted (EGC and EPS), and synthesized bead materials (GCB and PSB). GCB had a higher surface area than PSB whereas the particle size and pore size were smaller than PSB. GCP and PSP had heterogeneous cracking surfaces whereas GCB and PSB had sphere-shaped and rough surfaces. Carbon (C), oxygen (O), calcium (Ca), and functional groups of O–H, C–H, N–H, C–O, and C–Cl were found in GCP, PSP, GCB, and PSB. Both extracted and beaded materials demonstrated high antibacterial activities on Staphylococcus aureus and Escherichia coli by a disc diffusion assay, and GCB demonstrated high bacteria removals on both bacteria types by almost 100% by batch experiments. Freundlich isotherm and a pseudo-second-order kinetic model are good fit models for explaining the adsorption pattern and mechanism of GCB related to a physiochemical adsorption and chemisorption mechanism. Moreover, GCB could reuse more than 3 cycles, so it is possible to use GCB for disinfection in a wastewater treatment system.

Releasing contaminated dyes into water bodies might create environmental problems for water quality and toxic aquatic organisms. The toxicity of dyes might affect human health throughout the food chain, so it is necessary to treat contaminated dye in wastewater before discharging it into the water body. Chicken eggshell beads (CB), duck eggshell beads (DB), chicken eggshell beads mixed iron (III) oxide-hydroxide (CBF), duck eggshell beads mixed iron (III) oxide-hydroxide (DBF), chicken eggshell beads mixed zinc oxide (CBZ), and duck eggshell beads mixed zinc oxide (DBZ) were synthesized, and several characterized techniques of XRD, FESEM-FIB, EDX, and FTIR were used to identify the crystalline structure, surface morphology, and chemical composition and functional groups. Reactive blue 4 (RB4) dye removal efficiencies on dye adsorbent materials were investigated through batch experiments with varying doses, contact time, temperature, pH, and concentration. Their adsorption patterns and mechanisms also were studied by adsorption isotherm and kinetics. All dye adsorbent materials demonstrated semi-crystalline structures, and their surface morphologies had a spherical shape with coarse surfaces. Oxygen, carbon, calcium, chlorine, and sodium and four main function groups of OH, NH, CO, and COC were detected in all dye adsorbent materials. For batch tests, they could remove RB4 dye by more than 56%, and CBF represented the highest RB4 dye removal efficiency at 84.44%. Moreover, the addition of iron (III) oxide-hydroxide and zinc oxide helped to improve RB4 dye adsorbent efficiencies which an iron (III) oxide-hydroxide increased RB4 removal efficiency of chicken and duck eggshell beads more than zinc oxide. Their adsorption patterns and mechanisms were well explained by Freundlich and pseudo-second-order kinetic models. Therefore, all dye adsorbent materials especially CBF are potential dye adsorbent materials for further industrial applications.