scholarly journals Simultaneous Removal of Inorganic and Organic Pollutants from Polycontaminated Wastewaters on Modified Hemp-Based Felts

2021 ◽  
Vol 72 (1) ◽  
pp. 25-43
Author(s):  
Gregorio Crini ◽  
Corina Bradu ◽  
Cesare Cosentino ◽  
Jean-Noel Staelens ◽  
Bernard Martel ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Oxygen Demand ◽  
Hemp Fiber ◽  
Adsorption Capacities ◽  
Carboxylic Groups ◽  
Conventional Material ◽  
Butanetetracarboxylic Acid ◽  
Treatment Step

In this study, an adsorption process using hemp-based materials in felt form was applied to remove between 45 and 53 contaminants present in wastewater from the surface treatment industry. Several materials were compared using batch experiments, including a felt made of 100% hemp fiber (HEMP), the same felt cross-linked with 1,2,3,4-butanetetracarboxylic acid (HEMPBA), a felt coated with a maltodextrin-1,2,3,4-butanetetracarboxylic cross-linked polymer (HEMPM), and a felt coated with hydroxypropyl-a-cyclodextrin-1,2,3,4-butanetetra-carboxylic cross-linked polymer (HEMPCD). Chemical analysis showed that HEMPBA, HEMPM and HEMPCD materials had high adsorption capacities on metals in wastewater, confirming the role of carboxylic groups. Only HEMPCD was able to remove both metals and organics, resulting in the virtual elimination of organics such as chloroform, 1,2-dichlorobenzene, and nonylphenol. This result demonstrated the important role of cyclodextrin molecules in adsorption mechanism. HEMPCD also resulted in an important decrease in residual chemical oxygen demand and total organic carbon of more than 83% and 53%, respectively, while the treatment with HEMP lowered them by 12% and 12%, HEMPBA by 9% and 7%, and HEMPM by 45% and 26%. Chemical abatement and toxicity mitigation have demonstrated that adsorption onto a non-conventional material could be an interesting treatment step for the detoxification of wastewater.

scholarly journals Adsorption of p-Nitrophenol onto PDMDAAC-Modified Bentonites

2005 ◽  
Vol 23 (5) ◽  
pp. 407-416 ◽  
Author(s):  
Xianjia Peng ◽  
Zhaokun Luan ◽  
Hongmei Zhang ◽  
Binghui Tian ◽  
Bin Fan
Keyword(s):  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Interlayer Space ◽  
Removal Rate ◽  
Cost Effective ◽  
Dual Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Capacities ◽  
Ph Dependent

A novel organobentonite was prepared by modifying bentonite with poly(dimethyldiallylammonium chloride) (PDMDAAC), a harmless and cost-effective type of polycation. Zeta potential and X-ray diffraction measurements suggest that PDMDAAC was intercalated into the bentonite interlayer space. PDMDAAC—bentonite has been found to be effective for the removal of p-nitrophenol with a removal rate of 81.4% being achieved. The adsorption process was pH-dependent and was slightly decreased by the Ca2+ and Mg2+ ions co-existing in the solution. A dual-phase adsorption mechanism was suggested for the process. The adsorbents obtained from the regeneration of PDMDAAC—bentonite still exhibit good adsorption capacities.

scholarly journals Highly effective removal of antibiotics from aqueous solution by magnetic ZnFe2O4/activated carbon composite

2020 ◽  
Vol 82 (5) ◽  
pp. 877-886
Author(s):  
Yun-Xia Li ◽  
Lei Wang ◽  
Fang-Fang Chai ◽  
Hong-Fei Jing ◽  
Zhu-Qing Gao ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Adsorption Mechanism ◽  
Adsorption Process ◽  
Carbon Composite ◽  
Liquid System ◽  
Mechanism Analysis ◽  
Solution Ph ◽  
Adsorption Capacities ◽  
Effective Removal ◽  
Solid Liquid

Abstract Water pollution from antibiotics has attracted a lot of attention for its serious threat to human health. In this study, a magnetic adsorbent (zinc ferrite/activated carbon (ZnFe2O4/AC) was synthesized via microwave method to effectively remove gemifioxacin mesylate (GEM) and moxifloxacin hydrochloride (MOX). Based on the porosity of AC and the magnetism of ZnFe2O4, the resulting ZnFe2O4/AC has high adsorption capacities and can be easily separated from the solid–liquid system via a magnetic field. The largest adsorption capacities for GEM and MOX can reach up to 433.4 mg g−1 and 388.8 mg g−1, respectively, higher than those of reported adsorbents such as MIL-101 and MOF-808. Fastest adsorptions of GEM and MOX were found at 5 min, and solution pH and coexisting salts do not have a significant influence on the adsorption process. The adsorption mechanism analysis indicates that electrostatic interaction and H-bond interaction contribute to the effective adsorption.

scholarly journals Cross-linked cyclodextrin-based material for treatment of metals and organic substances present in industrial discharge waters

2016 ◽  
Vol 12 ◽  
pp. 1826-1838 ◽  
Author(s):  
Élise Euvrard ◽  
Nadia Morin-Crini ◽  
Coline Druart ◽  
Justine Bugnet ◽  
Bernard Martel ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Adsorption Mechanism ◽  
Metal Removal ◽  
Adsorption Sites ◽  
Industrial Discharge ◽  
Organics Removal ◽  
Adsorption Capacities ◽  
Carboxylic Groups ◽  
Polycyclic Aromatic ◽  
High Concentrations

In this study, a polymer, prepared by crosslinking cyclodextrin (CD) by means of a polycarboxylic acid, was used for the removal of pollutants from spiked solutions and discharge waters from the surface treatment industry. In spiked solutions containing five metals, sixteen polycyclic aromatic hydrocarbons (PAH) and three alkylphenols (AP), the material exhibited high adsorption capacities: >99% of Co2+, Ni2+ and Zn2+ were removed, between 65 and 82% of the PAHs, as well as 69 to 90% of the APs. Due to the structure of the polymer and its specific characteristics, such as the presence of carboxylic groups and CD cavities, the adsorption mechanism involves four main interactions: ion exchange, electrostatic interactions and precipitation for metal removal, and inclusion complexes for organics removal. In industrial discharge waters, competition effects appeared, especially because of the presence of calcium at high concentrations, which competed with other pollutants for the adsorption sites of the adsorbent.

Pb(II) biosorption on reed biosorbent derived from wetland: effect of pretreatment on functional groups

2006 ◽  
Vol 54 (10) ◽  
pp. 133-141 ◽  
Author(s):  
B. Southichak ◽  
K. Nakano ◽  
M. Nomura ◽  
N. Chiba ◽  
O. Nishimura
Keyword(s):  
Aqueous Solution ◽  
Adsorption Mechanism ◽  
Valuable Insight ◽  
Carboxylate Group ◽  
Who Guidelines ◽  
Adsorption Performance ◽  
Carboxylate Groups ◽  
Carboxylic Groups ◽  
Pretreatment Effects

Reed biomass harvested from wetland constructed for water purification was modified into a biosorbent for Pb(II) removal from aqueous solution. The enhancement of Pb(II) adsorption by reed biosorbent depended not only on the types of reagent used for pretreatment, but also on the pH during the pretreatment process. The mechanisms, as elucidated using relational data obtained from Boehm titration, Fisher esterification and FTIR, involved the conversion of carboxylic groups into carboxylate groups, and proved the role of the carboxylate group, which occupied more than 80% in binding Pb(II). The Langmuir sorption isotherm of Pb(II) by R-NaOH-12 showed Qmax and b values of 0.082 mmol/g and 312.5 g/mmol, suggesting enough adsorption performance to reduce the concentration of Pb(II) to meet the range of WHO guidelines. The salinity of aqueous solution containing NaH2PO4 and NaNO3 promoted the adsorption of Pb(II), while NaCl and Na2SO4 suppressed the adsorption capacity of Pb(II). The adsorption mechanism of reed biosorbent provides valuable insight on the pretreatment effects and the advantages of utilizing this plant as biosorbent for Pb(II) and other heavy metals.

scholarly journals STUDI ADSORPSI LOGAM Pb(II) DAN Cd(II) PADA ASAM HUMAT DALAM MEDIUM AIR

ALCHEMY ◽  
2013 ◽  
Author(s):  
Atik Rahmawati ◽  
Sri Juari Santoso
Keyword(s):  
Humic Acid ◽  
Adsorption Isotherm ◽  
Adsorption Process ◽  
Peat Soil ◽  
Water Medium ◽  
Batch Method ◽  
First Order ◽  
East Kalimantan ◽  
Adsorption Capacities ◽  
Carboxylic Groups

<p>It had been conducted a study on adsorption of Cd (II) and Pb (II) of humic acid isolated from peat soil from village of Sambutan, the subdistrict of Samarinda Ilir, East Kalimantan. Aspects studied covered adsorption kinetics and adsorption isotherm of Cd (II) and Pb (II) of humic acid in water medium.</p><p>Adsorption process carried out by batch method. Kinetics study conducted by intracting metal adsorption of Cd (II) and Pb (II) with humic acid at various times, meanwhile studying the adsorption isotherm is done by interacting Cd (II) and Pb (II) at various concentrations with humic acid.</p><p>The results showed the adsorption rate of Cd (II) and Pb (II) on humic acid followed first order with rate constants of Cd (II) and Pb (II) of 0.0012 and 0.0038 mg menit<sup>-1</sup>/10 humic acid. Carboxylic groups of humic acid as the main groups which were actively involved in the interaction of metal-humic acid and have experienced deprotonation is  hard nucleophile. It made Pb (II) was more quickly and easily adsorbed than Cd (II). Adsorption isotherm of Cd (II) and Pb (II) on humic acid followed the pattern of Langmuir isotherm with adsorption capacities of Pb (II) of 1.66 x10-3 mol / g and for Cd (II) 3.83 x10-3 mol / g . The adsorption energy of both metals is relatively small that is equal to 16.1 for Cd(II) and 21.4 kJ / mol for Pb(II).<strong></strong></p>

DECOLOURIZATION AND COD REMOVAL OF WASEWATER FROM ETHANOL PRODUCTION PROCESS FROM MOLASSES BY COAGULANTION USING INORGANIC ALUM

2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le
Keyword(s):  
Ethanol Production ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Treatment Processes ◽  
Physico Chemical ◽  
Biological Methods ◽  
Treatment Step ◽  
Main Material

The industrial production of ethanol by fermentation using molasses as main material that generates large quantity of wastewater. This wastewater contains high levels of colour and chemical oxygen demand (COD), that may causes serious environmental pollution. Most available treatment processes in Vietnam rely on biological methods, which often fail to treat waste water up to discharge standard. As always, it was reported that quality of treated wastewater could not meet Vietnameses discharge standard. So, it is necessary to improve the treatment efficiency of whole technological process and therefore, supplemental physico-chemical treatment step before biodegradation stage should be the appropriate choice. This study was carried out to assess the effect of coagulation process on decolourization and COD removal in molasses-based ethanol production wastewater using inorganic coaglutant under laboratory conditions. The experimental results showed that the reductions of COD and colour with the utilization of Al2(SO4)3 at pH 9.5 were 83% and 70%, respectively. Mixture FeSO4 – Al2(SO4)3 at pH 8.5 reduced 82% of colour and 70% of COD. With the addition of Polyacrylamide (PAM), the reduction efficiencies of colour, COD and turbidity by FeSO4 – Al2(SO4)3 were 87%, 73.1% and 94.1% correspondingly. It was indicated that PAM significantly reduced the turbidity of wastewater, however it virtually did not increase the efficiencies of colour and COD reduction. Furthermore, the coagulation processes using PAM usually produces a mount of sludge which is hard to be deposited.

Competitive adsorption mechanism of thiophene with benzene in FAU zeolite: The role of displacement

2017 ◽  
Vol 328 ◽  
pp. 172-185 ◽  
Author(s):  
Shanqing Dang ◽  
Liang Zhao ◽  
Qing Yang ◽  
Meng Zheng ◽  
Jingjing Zhang ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Competitive Adsorption ◽  
Fau Zeolite

scholarly journals The role of a chemical loop in removal of hazardous contaminants from coke oven wastewater during its treatment

2019 ◽  
Vol 17 (1) ◽  
pp. 1288-1300
Author(s):  
Anna Kwiecińska-Mydlak ◽  
Marcin Sajdak ◽  
Katarzyna Rychlewska ◽  
Jan Figa
Keyword(s):  
Chemical Treatment ◽  
Treatment Process ◽  
Oxygen Demand ◽  
Coke Oven ◽  
Main Role ◽  
Biological Processes ◽  
Coal Processing ◽  
Wastewater Treatment Process ◽  
Iron Based

AbstractCoke oven liquor is one of the most contaminated liquid streams generated by the coal processing industry, thus its proper treatment and utilization is crucial for sustainable and environmentally neutral plant operation. The conventional wastewater treatment process comprises of chemical and biological processes. Within the current research the detailed role of chemical treatment is described. Commercially available iron-based coagulants (PIX100, PIX100COP, PIX113, PIX116) were tested to understand their removal efficiency and impact on the stream parameters. The influence of iron dose in the range of 300-500 mgFe/L on the process performance was also examined.It was found that the main role of chemical treatment was to bind toxicants harmful to activated sludge microorganisms, i.e. free and complex cyanides and sulphides. Among the tested iron-based conventional coagulants ferrous salts were more efficient than ferric salts. It was also observed that efficiency of the process strongly depended on wastewater properties (especially in regard to pH, which should be in the range of 9-10) and the coagulant selection needed to be done individually for a given wastewater type. The removal rates of particular contaminants were diversified and for free cyanides, complex cyanides and sulphides they were in the range of 23-91%, -156-77% and -357-98%, respectively. The expected, simultaneous removal of chemical oxygen demand (COD) during the treatment was not observed and even the parameter value increased after the process due to probable formation of compounds less vulnerable to oxidation.

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