scholarly journals Adsorption of Pb(II) from Aqueous Solutions onto Humic Acid Modified by Urea-Formaldehyde: Effect of pH, Ionic Strength, Contact Time, and Initial Concentration

2021 ◽  
Vol 21 (6) ◽  
pp. 1371
Author(s):  
Meidita Kemala Sari ◽  
Rahmat Basuki ◽  
Bambang Rusdiarso
Keyword(s):  
Humic Acid ◽  
Ionic Strength ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Urea Formaldehyde ◽  
Attenuated Total Reflection ◽  
Kinetics Model ◽  
Cooh Group ◽  
X Ray ◽  
Solid Form

Humic acid (HA) and urea-formaldehyde (UF) have been frequently reported as heavy metal adsorbents. However, the literature has never written HA modification by UF to improve the adsorbent’s performance. In this study, a new adsorbent of humic acid-urea formaldehyde (HA-UF) was synthesized. The reaction of the conducted the formation of HA-UF –COOH group of HA with the –NH2 group of UF was evidenced by decreasing total acidity from 549.26 cmol/kg (in HA) to 349.30 cmol/kg (in HA-UF). The success of HA-UF formation was characterized by attenuated total reflection-infrared (ATR-IR), energy dispersive X-Ray (EDX), and X-ray diffraction (XRD). The high stability of HA-UF was shown by 96.8% remaining in solid form at pH 12.4. Adsorption behavior of Pb(II) onto HA-UF was influenced by the ionic strength and pH, which were mainly driven by the ion exchange mechanism (EDR = 9.75 kJ/mol). The higher ionic strength will affect decreasing adsorbed Pb(II) at the optimum pH of 5.5. The effect of initial Pb(II) concentration (isotherm) shows that the data fitted well with the Langmuir-b isotherm model indicated the monolayer adsorption of Pb(II) onto homogenous surfaces of the HA-UF with the adsorption capacity of 2.26 × 10–4 mol/g (which is higher than its original HA of 1.12 × 10–4 mol/g). The Ho (pseudo-second-order) kinetics model represented the effect of contact time (kinetics) was represented by the Ho kinetics model. The synthesized adsorbent is also reusable, with 88.59% of adsorption capacity remaining in the fifth recycle run. Therefore, the adsorbent of HA-UF is suggested to be a promising candidate for adsorption applications.

scholarly journals β-Cyclodextrin Modified Poly(Acrylonitrule-co-Acrylic Acid) Hydrogel for Thorium(IV) Adsorption

Polymers ◽  
2017 ◽  
Vol 9 (6) ◽  
pp. 201 ◽  
Author(s):  
Guojian Duan ◽  
Qiangqiang Zhong ◽  
Lei Bi ◽  
Liu Yang ◽  
Tonghuan Liu ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Ph Value ◽  
Water System ◽  
Maximum Adsorption Capacity ◽  
Practical Application ◽  
X Ray Diffraction ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

In this report, the β-CD(AN-co-AA) hydrogel was used to remove the thorium(IV) [Th(IV)] from the water system, and the new adsorbent was characterized through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The influences of contact time, pH value, ionic strength, solid-liquid ratio, initial Th(IV) concentration, and temperature on Th(IV) adsorption onto the functional hydrogel were researched. The results showed that the experimental data followed the Langmuir isotherm and the maximum adsorption capacity (qmax) for Th(IV) was 692 mg/g at pH 2.95, which approached the calculated (qe) 682 mg/g. The desorption capacity of Th(IV) in different HNO3 concentrations ranging from 0.005 to 0.5 M was also studied, and the percentage of the maximum desorption was 86.85% in the condition of 0.09 M HNO3. The selectivity of β-CD(AN-co-AA) hydrogel was also be studied, the results indicated that this material retained the good adsorption capacity to Th(IV) even when the Ca2+, Mg2+, or Pb2+ existed in the system. The findings indicate that β-CD(AN-co-AA) can be used as a new candidate for the enrichment and separation of Th(IV), or its analogue actinides, from large-volume solution in practical application.

Adsorption behavior of Th(IV) onto illite: Effect of contact time, pH value, ionic strength, humic acid and temperature

2016 ◽  
Vol 127-128 ◽  
pp. 35-43 ◽  
Author(s):  
Zhang Hongxia ◽  
Wang Xiaoyun ◽  
Liang Honghong ◽  
Tan Tianshe ◽  
Wu Wangsuo
Keyword(s):  
Humic Acid ◽  
Ionic Strength ◽  
Contact Time ◽  
Ph Value ◽  
Adsorption Behavior

Disinfection performance of nanosilver and impacts of environmental conditions on viral inactivation by nanosilver

2013 ◽  
Vol 14 (1) ◽  
pp. 150-157 ◽  
Author(s):  
Yang Xu ◽  
Xiaona Chu ◽  
Jiangyong Hu ◽  
Say Leong Ong
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Humic Acid ◽  
Ionic Strength ◽  
Environmental Conditions ◽  
Contact Time ◽  
Chloride Ion ◽  
Viral Inactivation ◽  
E Coli ◽  
High Concentrations

Three types of nanosilver materials, which were commercial, chemically-synthesized and biologically-synthesized, respectively, were compared in terms of the disinfection efficiencies against Escherichia coli and MS2 coliphage in order to pinpoint promising material with the best performance. Disinfection results showed biologically-synthesized silver nanoparticles (referred to hereafter as ‘bio-AgNPs’) had the best disinfection performance, 10 mg/L of which was able to inactivate all the E. coli in 1 min (>6 log removals) and achieved 4 log removals of MS2 coliphage. Bio-AgNPs were therefore selected for further study in terms of effects of the concentration and contact time as well as the impacts of environmental conditions on the viral inactivation. Given the viral inactivation profile of bio-AgNPs shown in this study, it could be concluded that viral inactivation by bio-AgNPs could be inhibited by total organic carbon (TOC) (10 mg/L as humic acid) and chloride ion (5 mg/L) to a large extent while Ca2+/Mg2+/ionic strength only had minor effects on the viral inactivation at high concentrations (188 mg/L as CaCO3 of hardness or 5.6 mM of ionic strength, respectively). This part of the study may help enlighten further mechanism studies on viral inactivation by nanosilver.

β-Zeolite modified by ethylenediamine for sorption of Th(IV)

2017 ◽  
Vol 105 (6) ◽  
Author(s):  
Liu Peng ◽  
Wu Hanyu ◽  
Yuan Ni ◽  
Yin Zhuoxin ◽  
Pan Duoqiang ◽  
...  
Keyword(s):  
Steady State ◽  
Humic Acid ◽  
Ionic Strength ◽  
Contact Time ◽  
Surface Complexation ◽  
Sorption Isotherms ◽  
Ph Values ◽  
Β Zeolite ◽  
Batch Technique ◽  
Pseudo Second Order

Abstractβ-Zeolite-EDA was modified with ethylenediamine (EDA) after synthesized. The synthesized material was characterized and used for removal of Th(IV) from aqueous solutions. The influences of pH, ionic strength, contact time, temperature and humic acid (HA) on Th(IV) sorption onto synthesized β-zeolite-EDA was studied by batch technique. The dynamic process showed that the sorption of Th(IV) onto β-zeolite-EDA matched the pseudo-second-order kinetics model. The sorption of Th(IV) on β-zeolite-EDA was significantly dependent on pH values, the sorption percentage increased markedly at pH 3.5–4.5, and then maintained a steady state as pH values increased. Through simulating the sorption isotherms by Langmuir, Freundlich and Dubini–Radushkevich (D–R) models, it could be seen respectively that the sorption pattern of Th(IV) on β-zeolite-EDA was mainly controlled by surface complexation, and that the sorption processes was endothermic and spontaneous. The presence of HA increased Th(IV) sorption on β-zeolite-EDA.

scholarly journals Adsorpsi Asam Humat pada Zeolit Alam yang Dimodifikasi dengan TiO2

2020 ◽  
Vol 11 (1) ◽  
pp. 43-51
Author(s):  
Upita Septiani ◽  
Fiska Julian Tasari ◽  
Zilfa Zilfa
Keyword(s):  
Humic Acid ◽  
Adsorption Capacity ◽  
Natural Zeolite ◽  
Sol Gel ◽  
Sem Analysis ◽  
Maximum Adsorption Capacity ◽  
Natural Zeolites ◽  
X Ray ◽  
West Sumatra ◽  
Silica Alumina

This research modified natural zeolite with TiO2 synthesized by the sol-gel process which was applied as a humic acid adsorbent. The purpose of this study was to coat natural zeolites with TiO2 to increase the adsorption capacity of natural zeolites as humic acid adsorbents. The natural zeolite powders were obtained from Kabupaten Solok, West Sumatra, based on X-ray Fluorescence (XRF) analysis, the ratio of silica/alumina (Si/Al) was 4.35, indicating that natural zeolite was clinoptilolite zeolite. Scanning Electron Microscopy (SEM) analysis showed natural zeolite has a rough surface with closed pores while zeolite coated with TiO2 (zeolite/TiO2) has a homogeneous, smooth surface with open pore. The results of the Energy Dispersive X-Ray Spectroscopy (EDS) analysis showed that the level of TiO2 was 7.1%, this result showed that TiO2 has been coated on the surface of the zeolite. Natural zeolite and zeolite/TiO2 were applied as humic acid adsorbents. Maximum adsorption capacity of natural zeolites and zeolites/TiO2 were 0.2787 mg/g and 1.199 mg/g, respectively.

scholarly journals Characterization and Interpretation of Cd (II) Adsorption by Different Modified Rice Straws under Contrasting Conditions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shuai Wang ◽  
Nan Wang ◽  
Kai Yao ◽  
Yuchuan Fan ◽  
Wanhong Li ◽  
...  
Keyword(s):  
Citric Acid ◽  
Ionic Strength ◽  
Adsorption Capacity ◽  
Rice Straw ◽  
Contact Time ◽  
Ph Value ◽  
Batch Adsorption ◽  
Acid Modification ◽  
Adsorption Capacities ◽  
Straw Ash

AbstractRice straw can adsorb Cd(II) from wastewater, and modification of rice straw may improve its adsorption efficiency. The rice straw powder (Sp) from the direct pulverization of rice straw was used as the control, the rice straw ash (Sa), biochar (Sa), and modified rice straw (Ms) were prepared by ashing, pyrolysis and citric acid modification, respectively, and all of them were examined as adsorbents for Cd(II) in this study. Batch adsorption experiments were adopted to systematically compare the adsorption capacities of rice straw materials prepared with different modification methods for Cd(II) from aqueous solution under different levels of initial Cd(II) concentration (0–800 mg·L−1), temperature (298, 308, and 318 K), contact time (0–1440 min), pH value (2–10), and ionic strength (0–0.6 mol·L−1). The results indicated that the modification method affected the adsorption of Cd(II) by changing the specific surface area (SSA), Si content, surface morphology, and O-containing functional group of rice straw. Compared with Sp, Ms held more surface O–H, aliphatic and aromatic groups, while Sa had more phenolic, C–O (or C–O–C), and Si–O groups, and Sb held more C–O (or C–O–C) and Si–O groups; besides, Sa, Sb, and Ms had larger SSA than Sp. Adsorption capacity of the four adsorbents for Cd(II) increased and gradually became saturated with the increase in the initial Cd(II) concentration (0–800 mg·L−1). The adsorption capacity of Cd(II) was significantly higher at 318 K than 298 K and 308 K, regardless of the adsorbent type. Sa had the largest SSA (192.38 m2·g−1) and the largest adsorption capacity for Cd(II). When the initial Cd2+ concentration was at 800 mg·L−1, the Cd(II) adsorption amount reached as high as 68.7 mg·g−1 with Sa at 318 K. However, the SSA of Sp was only 1.83 m2·g−1, and it had the least adsorption capacity for Cd(II). Only the adsorption of Cd(II) upon Sb at 298 K was spontaneous, and surprisingly, all other adsorptions were nonspontaneous. These adsorptions were all chemical, and were favorable, exothermic and order-increasing processes. The pseudo-second-order model showed a strong fit to the kinetics of Cd(II) adsorption by the four adsorbents. The adsorption capacities of Cd(II) by the adsorbents were less at low pH, and all were enhanced with the increase of initial pH value (2–10) in the solution. The inhibiting effect on Cd(II) adsorption due to the increase in ionic strength was greater with Sa, Sb, and Ms than that under Sp. The rice straw ash prepared by ashing unexpectedly had greater adsorption capacity for Cd(II) than the biochar and citric acid modified rice straw. The optimum condition for Cd(II) adsorption was established as the temperature of 318 K, initial Cd(II) concentration of 800 mg·L−1, contact time of 240 min, and no Na(I) interference regardless of absorbent. In conclusion, rice straw ash shows the greatest potential of being applied to paddy fields for the remediation of Cd(II) pollution so as to reduce the risk of Cd(II) enrichment in rice grains and straws.

scholarly journals ADSORPTION OF Am-241, Cs-137 AND Sr-90 RADIONUCLIDES WITH BENTONITE-HUMIC ACID IMMOBILIZED YIELD

2010 ◽  
Vol 10 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Kris Tri Basuki ◽  
Muzakky Muzakky
Keyword(s):  
Infrared Spectroscopy ◽  
Humic Acid ◽  
Ionic Strength ◽  
Optimum Condition ◽  
Visual Minteq ◽  
X Ray ◽  
As Species ◽  
Infra Red ◽  
Adsorbent Materials

Adsorption of Am-241, Cs-137 and Sr-90 radionuclides to bentonite-humic acid immobilized yield have been done. The aims of this study are (1) making of adsorbent materials from resulted immobilization humic acid into bentonite mineral, and it's characterization with spectroscopy infrared and X-ray diffractometer and (2) adsorption of Am-241, Cs-137 and Sr-90 radionuclides into bentonite mineral as adsorbent at various pH. Experiments showed that result of immobilization of bentonite-humic acid were optimum at 100 g bentonite, 60 g humic acid, 0.1 M NaNO3 ionic strength, and 2.5 pH. At the optimum condition bentonite could be bonded by the functional COOH from humic acid maximum equal to 75.2%. Base on infrared spectroscopy and X-ray diffractometer showed that humic acid can immobilized into bentonite to form of bentonite-humic acid alloy. Application of adsorbent bentonite-humic acid immobilized yield to adsorb radionuclides of Am-241, Cs-137 and of Sr-90, showed that can adsorb at the range of pH 3 until 10. The phenomenon adsorption as species radionuclides was predicted by ";;Visual minteq";; software. By each the feeds of radionuclide 0.001 mMol/L, 0.1 M NaNO3 ionic strength and pH 5 showed that bentonite-humic acid can adsorb radionuclides 98.50-99.1% of Am-241, Cs-137, and Sr-90.   Keywords: immobilisation, adsorption, infra red spectroscopy, X-ray diffractometer

scholarly journals ADSORPTION OF GIBBERELLIC ACID ONTO NATURAL KAOLIN FROM TATAKAN, SOUTH KALIMANTAN

2010 ◽  
Vol 9 (3) ◽  
pp. 373-379 ◽  
Author(s):  
Sunardi Sunardi ◽  
Yateman Arryanto ◽  
Sutarno Sutarno
Keyword(s):  
Adsorption Isotherm ◽  
Gibberellic Acid ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Adsorption Process ◽  
Langmuir Adsorption Isotherm ◽  
Purification Process ◽  
X Ray ◽  
Langmuir Adsorption ◽  
Batch System

Adsorption of gibberellic acid (GA3) onto raw and purified kaolin from Tatakan, South Kalimantan was investigated in this study. Purification process was done by sedimentation to obtain relative pure kaolinite. Raw and purified kaolin samples were characterized by Fourier transformed infrared (FTIR) spectroscopy and X-ray diffractometer (XRD). The adsorption process was carried out in a batch system and the effect of pH, contact time and GA3 concentration were experimentally studied to evaluate the adsorption capacity. The amount of GA3 adsorbed was determined by UV spectrophotometer. The result showed that the raw kaolin from South Kalimantan consist of 53.36% kaolinite, 29.47% halloysite, 4.47% chlorite, 11.32% quartz and 1.38% christobalite and the purified kaolin consist of 73.03% kaolinite, 22.6% halloysite, 0.77% chlorite, 1.37% quartz and 2.23% christobalite Adsorption experimental indicate that the optimum adsorption took place at pH 7 and contact time for 4 h. Adsorption of GA3 was described by the Langmuir adsorption isotherm model with adsorption capacity of 8.91 mg/g on raw kaolin and 10.38 mg/g on purified kaolin.   Keywords: kaolin, gibberellic acid, adsorption

scholarly journals Removal of Cd(II) from Water by HPEI Modified Humin

2020 ◽  
Vol 12 (19) ◽  
pp. 7931
Author(s):  
Sanmei Li ◽  
Mingda Wu ◽  
Linghong Lu ◽  
Jiabao Zhu
Keyword(s):  
Humic Acid ◽  
Adsorption Capacity ◽  
Low Cost ◽  
Raw Material ◽  
Flame Atomic Absorption Spectroscopy ◽  
X Ray ◽  
Adsorption Performance ◽  
Flame Atomic Absorption ◽  
Weathered Coal ◽  
Cost Treatment

Humin is the waste residue from the process of preparing humic acid, which accounts for a large proportion of the raw material (weathered coal humic acid). Its Cd(II) adsorption performance is far inferior to that of humic acid. How to regenerate humin is of great significance to the low-cost treatment of Cd(II) pollution in wastewater. In this study, humin was modified by hyperbranched polyethyleneimine to enhance the adsorption capacity for Cd(II). Fourier transform infrared spectroscopy and the X-ray photoelectron spectrometer showed that hyperbranched polyethyleneimine was grafted to the surface of humin. Flame atomic absorption spectroscopy showed that the saturated Cd(II) adsorption capacity of the modified humin was increased to 11.975 mg/g, which is about 5 times than that of humin and is also higher than that of humic acid. The adsorption kinetics, adsorption isotherm, and thermodynamic properties of humic acid, humin, and modified humin were also studied. This study may provide a foundation for research utilizing natural resources to reduce heavy metal pollution in the environment.

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