Health and environment
Ahmad Alahabadi; Abolfazl Rahmani Sani; Zahra Rezai; Mahnaz Torabi
Volume 25, Issue 4 , September and October 2018, , Pages 528-536
Abstract
Background and Background and goal : The attendance of humic acid in water resources is the main health problems of many Societies. There are various methods for decreasing or removing of humic acid. Of these absorbed is considered an effective method to remove it. SO Agriculture wastes were used for ...
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Background and Background and goal : The attendance of humic acid in water resources is the main health problems of many Societies. There are various methods for decreasing or removing of humic acid. Of these absorbed is considered an effective method to remove it. SO Agriculture wastes were used for preparation of activated carbons by chemical activation using Ammonium chloride.Method: In this study, the standard Merck carbon and carbon produced from plant waste used as adsorbents and adsorption experiments were performed in batc. Adsorption of humic acid (HA) on SAC and NAC as a function of solution initial pH (2-10), adsorbent dosage (0.1-1 g/L), contact time (5-50 min), concentration (5-20 mg/L), on the adsorption capacity, the two-parameter equilibrium models (Langmuir and Freundlich equations) were debated. Result: The result showed that the pH effect at removal humic acid is an important parameter, and isotherm showed that the adsorption Followed of the Langmuir isotherm. Also it was found that the capacity of absorb can be markedly effected by carbon type. That it was 238, 294 , 250 mg/g For carbons Merck, Sycamore and steel respectively.Conclusion: Carbon prepared from Steel due to very high capacity could be effective for removal humic acid from aqueous solution.
Abdolmotalleb Seyyed Mohammadi; Ghorban Asgari; MohammadTaghi Samadi; Ali Pour Mohammadi; Ali Faramarzi Govhar
Volume 22, Issue 4 , September and October 2015, , Pages 571-580
Abstract
Background and aim: Humic Acid (HA) is one of the polyelectrolyte compounds which cause many problems in water treatment process. In present study, UV/IO4- as a novel advance oxidation process, was used for removing HA. Material and methods: In present research, a batch reactor in lab scale was used.This ...
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Background and aim: Humic Acid (HA) is one of the polyelectrolyte compounds which cause many problems in water treatment process. In present study, UV/IO4- as a novel advance oxidation process, was used for removing HA. Material and methods: In present research, a batch reactor in lab scale was used.This reactor with useful volume of 2.5 L, made of stainless steel, which equipped with a low pressure Hg vapor lamp. In this study the effect of some parameters including pH, initial HA concentration, IO4- concentration and Fe (0) nanoparticles concentration were investigated. HA concentration was determined using Spectrophotometer at an absorbance wavelength of 254 nm. Results: According to the results, pH 3, periodate concentration 125 mg/L and Fe (0) Nano particles 12.5 mg/L were determined as optimum conditions. Moreover, results indicated that in presence of UV coupled with Periodate removal efficiency of HA increased to 66.08%, and the increase of Fe (0) Nano particles can led to increase HA removal (73.3%). Conclusion: Results show thatthe presence of UV letto increase in the activation of periodate, on the other hands, the presence of Fe (0) Nano particles led to further activation of periodate subsequently cause the increasing HA removal.
Samaneh Ghodrati; Seyyed Gholamreza Mosavi; ahmad Allahabadi
Volume 22, Issue 3 , May and June 2015, , Pages 270-281
Abstract
Background: Removal of humic acids during water treatment is important because it can react readily with chlorine and produce carcinogen compounds. In this study, performance, kinetic and isotherm of humic acid (HA) adsorption onto NH4Cl-induced activated carbon (NAC) has been investigated and compared ...
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Background: Removal of humic acids during water treatment is important because it can react readily with chlorine and produce carcinogen compounds. In this study, performance, kinetic and isotherm of humic acid (HA) adsorption onto NH4Cl-induced activated carbon (NAC) has been investigated and compared to the standard activated carbon (SAC).
Materials and Methods: NAC and SAC were used as the adsorbent in the present work and adsorption experiments were performed in batch mode. Adsorption of humic acid (HA) on SAC and NAC as a function of solution initial pH (2-10), adsorbent dosage (0.1-0.4 g/L), contact time (5-70 min), and adsorbate concentration (5-20 mg/L) was investigated.
Results: NAC exhibited higher HA adsorption capacity than that of SAC and HA adsorption capacities for both decreased with increasing solution initial pH in range of 2 to 10. The HA removal efficiencies of SAC and NAC were found to increase with increasing the adsorbent dosage. The adsorption kinetics data were well fitted by pseudo-second-order equation. The mechanisms of the adsorption of HA on SAC and NAC at pH 7 may include electrostatic attraction and hydrogen bonding. The adsorption isotherm data showed that adsorption behavior of HA well fitted by Langmuir adsorption isotherm for both NAC and SAC. The maximum adsorption capacity was 93.45 and 67.57 mg/g for NAC and SAC, respectively.
Conclusion: The results revealed that NAC has significantly removed HA from aqueous solutions compared to SAC and even many other adsorbents. Thus NAC as a cheap and more appropriate adsorbent can be used for removal of humic substances from polluted waters.