0000000001229493
AUTHOR
Hanna Runtti
showing 14 related works from this author
Activated Carbon from Renewable Sources: Thermochemical Conversion and Activation of Biomass and Carbon Residues from Biomass Gasification
2017
Activated carbon is one of the most widely applied adsorbent. As a porous carbon, it is used for the purification of both gaseous and liquid emissions. Activated carbon is prepared from fossil resources, such as coal, or from biomass through (hydro)thermal processing followed by chemical and/or physical activation. Further, some biomass thermal treatment processes, such as biomass gasification, produce carbon residues that can be modified to activated carbon with physical or chemical activation methods. The desired properties of activated carbon, i.e. high specific surface area and porosity, high carbon content and excellent sorption capacity, can be modified and optimized during thermochem…
Bisphenol A removal from water by biomass-based carbon: isotherms, kinetics and thermodynamics studies
2018
Biomass-based carbon was modified and used as an efficient bisphenol A (BPA) sorbent. The simple and environmentally friendly modification method produced sorbent with a capacity of 41.5 mg/g. The ...
Sulphate removal over barium-modified blast-furnace-slag geopolymer
2016
Blast-furnace slag and metakaolin were geopolymerised, modified with barium or treated with a combination of these methods in order to obtain an efficient SO4(2-) sorbent for mine water treatment. Of prepared materials, barium-modified blast-furnace slag geopolymer (Ba-BFS-GP) exhibited the highest SO4(2-) maximum sorption capacity (up to 119mgg(-1)) and it compared also favourably to materials reported in the literature. Therefore, Ba-BFS-GP was selected for further studies and the factors affecting to the sorption efficiency were assessed. Several isotherms were applied to describe the experimental results of Ba-BFS-GP and the Sips model showed the best fit. Kinetic studies showed that th…
How to tackle the stringent sulfate removal requirements in mine water treatment-A review of potential methods.
2018
Abstract Sulfate (SO₄²⁻) is a ubiquitous anion in natural waters. It is not considered toxic, but it may be detrimental to freshwater species at elevated concentrations. Mining activities are one significant source of anthropogenic sulfate into natural waters, mainly due to the exposure of sulfide mineral ores to weathering. There are several strategies for mitigating sulfate release, starting from preventing sulfate formation in the first place and ending at several end-of-pipe treatment options. Currently, the most widely used sulfate-removal process is precipitation as gypsum (CaSO₄·2H₂O). However, the lowest reachable concentration is theoretically 1500 mg L⁻¹ SO₄²⁻ due to gypsum’s solu…
Sulphate removal over barium-modified blast-furnace-slag geopolymer
2016
Blast-furnace slag and metakaolin were geopolymerised, modified with barium or treated with a combination of these methods in order to obtain an efficient SO42− sorbent for mine water treatment. Of prepared materials, barium-modified blast-furnace slag geopolymer (Ba-BFS-GP) exhibited the highest SO42− maximum sorption capacity (up to 119 mg g−1) and it compared also favourably to materials reported in the literature. Therefore, Ba-BFS-GP was selected for further studies and the factors affecting to the sorption efficiency were assessed. Several isotherms were applied to describe the experimental results of Ba-BFS-GP and the Sips model showed the best fit. Kinetic studies showed that the so…
Removal of ammonium from municipal wastewater with powdered and granulated metakaolin geopolymer
2017
Abstract Ammonium (NH₄⁺) removal from municipal wastewater poses challenges with the commonly used biological processes. Especially at low wastewater temperatures, the process is frequently ineffective and difficult to control. One alternative is to use ion-exchange. In the present study, a novel NH4+ ion-exchanger, metakaolin geopolymer (MK-GP), was prepared, characterised, and tested. Batch experiments with powdered MK-GP indicated that the maximum exchange capacities were 31.79, 28.77, and 17.75 mg/g in synthetic, screened, and pre-sedimented municipal wastewater, respectively, according to the Sips isotherm (R² ≥ 0.91). Kinetics followed the pseudo-second-order rate equation in all case…
Utilisation of barium-modified analcime in sulphate removal: Isotherms, kinetics and thermodynamics studies
2017
Abstract Analcime and commercial zeolite were employed as a precursor for preparing sorbent material for SO42− removal over barium modification. Three sorbents were prepared: barium-modified analcime (ANA-Na-Ba), barium-modified acid-washed analcime (ANA-Ac-Na-Ba) and barium-modified zeolite (ZSM5-Na-Ba). Of the prepared materials, ANA-Ac-Na-Ba was the most efficient sorbent material for SO42− removal, with a maximum sorption uptake of 13.7 mg g−1 at room temperature. Batch sorption experiments were performed to evaluate the effect of initial pH, initial SO42− concentration, sorbent dosage, temperature and contact time of sorption. Several isotherms were applied to describe the experimental…
Sulphate Removal from Water by Carbon Residue from Biomass Gasification: Effect of Chemical Modification Methods on Sulphate Removal Efficiency
2016
Sulphate removal from mine water is a problem because traditional chemical precipitation does not remove all sulphates. In addition, it creates lime sediment as a secondary waste. Therefore, an inexpensive and environmental-friendly sulphate removal method is needed in addition to precipitation. In this study, carbon residues from a wood gasification process were repurposed as precursors to a suitable sorbent for SO42- ion removal. The raw material was modified using ZnCl2, BaCl2, CaCl2, FeCl3, or FeCl2. Carbon residues modified with FeCl3 were selected for further consideration because the removal efficiency toward sulphate was the highest. Batch sorption experiments were performed to eval…
New processes of the circular economy in water and wastewater treatment : Waterpro project publication
2021
This report presents results of research done in the WaterPro project New processes of the circular economy in water and wastewater treatment. In this project, water treatment solutions based on material streams produced as sidestreams or wastestreams of industrial processes or mining were researched and developed. These materials were modified for use as adsorbents or precipitation chemicals for water treatment solutions aiming to remove nutrients or metals. Materials such as paper mill sludge, slag, fly ash, jarosite, analcime, and brucite were used. Adsorption, chemical precipitation, and electrochemical precipitation were applied as water purification methods. Experiments were performed…
Bisphenol A removal from water by biomass-based carbon : Isotherms, kinetics and thermodynamics studies
2020
Biomass-based carbon was modified and used as an efficient bisphenol A (BPA) sorbent. The simple and environmentally friendly modification method produced sorbent with a capacity of 41.5 mg/g. The raw material was modified with FeCl3 (Fe-CR), treated with hydrochloric acid (H-CR) or modified with CaCl2 (Ca-CR). Batch sorption experiments were performed to evaluate the effects of the initial pH, sorbent dosage, temperature, and contact time on BPA removal. BPA removal with modified carbons was notably higher than that with unmodified carbon. All sorbent materials exhibited very high sorption capacities and compared favourably to materials reported in the literature. Several isotherms were ap…
Removal of ammonium ions from aqueous solutions using alkali-activated analcime as sorbent
2023
Five alkali-activated analcime (ANA) sorbents (ANA-MK 1, ANA 2, ANA 3, ANA-MK 4, and ANA-MK 5) were developed for ammonium (NH4+) ion removal. Acid treatment and calcination were used as pre-treatments for analcime, and metakaolin (MK) was used as a blending agent in three sorbents. Sorption experiments were performed to evaluate the effects of sorbent dosage (1–20 g L−1), initial NH4+ ion concentration (5–1000 g L−1), and contact time (1 min–24 h). ANA-MK 1, ANA 2, and ANA-MK 4 were the most efficient sorbents for NH4+ ion removal, with a maximum experimental sorption uptake of 29.79, 26.00, and 22.24 mg g−1, respectively. ANA 3 and ANA-MK 5 demonstrated…
Zinc Adsorption by Activated Carbon Prepared from Lignocellulosic Waste Biomass
2019
Sawdust was used as a precursor for the production of biomass-based activated carbon. Carbonization and activation are single-stage processes, and steam was used as a physical activation agent at 800 °
Alkali-Activated Adsorbents from Slags: Column Adsorption and Regeneration Study for Nickel(II) Removal
2021
Alkali-activated adsorbents were synthesized by mixing three different slags from the steel industry: blast furnace slag (BFS), ladle slag (LS), and Lintz–Donawitz converter slag (LD). These powdered slag-based geopolymers (GP) were used to remove nickel(II) from aqueous solutions in fixed-bed column studies. The experiments were conducted in pH 6 using a phosphate buffer with initial nickel(II) concentration of 50 mg/L. Samples were taken at time intervals of between 5 and 90 min. Three adsorption–desorption cycles were implemented with a flow rate of 5 mL/min. The geopolymers were characterized by Fourier-Transform Infrared Spectroscopy (FTIR), X-ray powder diffraction (XRD), Field Emissi…
Bisphenol A removal from water by biomass-based carbon: isotherms, kinetics and thermodynamics studies
2018
Biomass-based carbon was modified and used as an efficient bisphenol A (BPA) sorbent. The simple and environmentally friendly modification method produced sorbent with a capacity of 41.5 mg/g. The raw material was modified with FeCl3 (Fe-CR), treated with hydrochloric acid (H-CR) or modified with CaCl2 (Ca-CR). Batch sorption experiments were performed to evaluate the effects of the initial pH, sorbent dosage, temperature, and contact time on BPA removal. BPA removal with modified carbons was notably higher than that with unmodified carbon. All sorbent materials exhibited very high sorption capacities and compared favourably to materials reported in the literature. Several isotherms were ap…