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Preparation of circular economy-based adsorbents and their usage for wastewater treatment in batch and fixed bed columns
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Industrial wastewater contains harmful contaminants like ammonium, heavy metals (e.g. nickel, cobalt, zinc), and cationic dyes (e.g. methylene blue), posing environmental and health risks. This study develops cost-effective, eco-friendly alkali-activated adsorbents for wastewater treatment from industrial side-streams (analcime and steel industry slags), activated with sodium hydroxide and sodium silicate or potassium silicate. Experiments were designed to assess the effectiveness of these adsorbents in removing wastewater pollutants. Initially, the efficiency of removing ammonium ion pollutants from aqueous solutions was tested, and the results (29.79 mg/g) were used as guidance in refining the synthesis conditions of the adsorbents to optimize their structural and chemical properties to ensure more effective adsorption capacities. The batch experiments demonstrated the rate of ammonium ions captured by the adsorbent surface and the interaction between the adsorbent and ammonium ions provides insight into the efficiency of the process under controlled experimental conditions.
Continuous fixed-bed column studies were then conducted to investigate the performance of the adsorbents under various conditions and to simulate practical wastewater treatment scenarios and evaluate the effectiveness of a continuous flow system. The fixed-bed columns demonstrated the adsorption behavior of multiple contaminants and the adsorption capacity was 3.26 mg/g, 13.92 mg/g, 6.86 mg/g, 6.39 mg/g and 18.9 mg/g for ammonium, zinc, cobalt, nickel and cationic dyes, respectively. The results showed that alkali-activated adsorbents were highly effective among the pollutants studied. The adsorbents´ reusability was evaluated by a regeneration study and the results confirmed their pollutant removal capacity over different cycles. Adsorbents preserved their pollutant removal capacity over successive regeneration experiments. This demonstrated stability highlights their potential for repeated use in continuous wastewater treatment operations and illuminates their economic and environmental advantages. Overall, the findings validated the effectiveness of alkali-activated adsorbents synthesized from industrial side-streams in wastewater treatment. Original papers Runtti, H., Sundhararasu, E., Pesonen, J., Tuomikoski, S., Hu, T., Lassi, U., & Kangas, T. (2023). Removal of ammonium ions from aqueous solutions using alkali-activated analcime as sorbent. ChemEngineering, 7(1), 5. https://doi.org/10.3390/chemengineering7010005 https://doi.org/10.3390/chemengineering7010005 Self-archived version Sundhararasu, E., Tuomikoski, S., Runtti, H., Hu, T., Varila, T., Kangas, T., & Lassi, U. (2021). Alkali-activated adsorbents from slags: Column adsorption and regeneration study for nickel(II) removal. ChemEngineering, 5(1), 13. https://doi.org/10.3390/chemengineering5010013 https://doi.org/10.3390/chemengineering5010013 Self-archived version Sundhararasu, E., Runtti, H., Kangas, T., Pesonen, J., Lassi, U., & Tuomikoski, S. (2022). Column adsorption studies for the removal of ammonium using Na-zeolite-based geopolymers. Resources, 11(12), 119. https://doi.org/10.3390/resources11120119 https://doi.org/10.3390/resources11120119 Self-archived version Sundhararasu, E., Runtti, H., Kangas, T., Lassi, U., & Tuomikoski, S. (2025). Slag-based alkali-activated adsorbent for efficiently removing ternary heavy metals and dye in wastewater. Manuscript in preparation. Tiivistelmä
Teollisuuden jätevedet sisältävät haitallisia epäpuhtauksia, kuten ammoniumia, raskasmetalleja (esim. nikkeli, koboltti, sinkki) ja kationisia väriaineita (esim. metyleenisininen), jotka aiheuttavat ympäristö- ja terveysriskejä. Tässä tutkimuksessa kehitettiin kustannustehokkaita ja ympäristöystävällisiä alkaliaktivoituja adsorbentteja jäteveden käsittelyyn hyödyntämällä teollisuuden sivuvirtoja (analsiimi ja terästeollisuuden kuonat). Kokeissa testattiin adsorbenttien tehokkuutta jäteveden epäpuhtauksien poistamisessa. Aluksi testattiin ammoniumionien poistotehokkuutta vesiliuoksista ja tulosten (29,79 mg/g) pohjalta muokattiin adsorbenttien synteesiolosuhteita niiden rakenteellisten ja kemiallisten ominaisuuksien optimoimiseksi tavoitteena parantaa materiaalin adsorptiokykyä. Panoskokeet osoittivat nopean ja tehokkaan ammoniumin adsorboinnin kontrolloiduissa koeolosuhteissa.
Kolonnikokeet simuloivat käytännön olosuhteita jätevedenpuhdistuksessa. Kolonnikokeet osoittivat useiden epäpuhtauksien, kuten ammoniumionien, raskasmetallien ja kationisen väriaineen, poistotehokkuuden. Adsorptiokapasiteetti oli 3,26, 13,92, 6,86, 6,39 ja 18,9 mg/g ammoniumin, sinkin, koboltin, nikkelin ja väriaineen poistossa. Adsorbenttien uudelleenkäytettävyys arvioitiin regenerointitutkimuksella. Tulokset vahvistivat adsorbentin epäpuhtauksien poistokapasiteetin useilla adsorptio-desorptiosykleillä. Adsorbentit säilyttivät epäpuhtauksien poistokykynsä peräkkäisten regenerointikokeiden aikana. Adsorbentin käytettävyys useissa sykleissä osoittaa taloudellisia ja ympäristöllisiä etuja.
Yhteenvetona tutkimus vahvistaa, että teollisuuden sivuvirroista syntetisoidut alkaliaktivoidut adsorbentit ovat tehokas ratkaisu jäteveden käsittelyyn. Adsorptiokyky ammoniumille, raskasmetalleille ja väriaineille oli suuri. Näiden tulosten ohella adsorbenttien tehokas regenerointi osoitti mahdollisuudet teollisuuden jätevesien käsittelyyn ympäristöystävällisellä ja kustannustehokkaalla tavalla. Osajulkaisut Runtti, H., Sundhararasu, E., Pesonen, J., Tuomikoski, S., Hu, T., Lassi, U., & Kangas, T. (2023). Removal of ammonium ions from aqueous solutions using alkali-activated analcime as sorbent. ChemEngineering, 7(1), 5. https://doi.org/10.3390/chemengineering7010005 https://doi.org/10.3390/chemengineering7010005 Rinnakkaistallennettu versio Sundhararasu, E., Tuomikoski, S., Runtti, H., Hu, T., Varila, T., Kangas, T., & Lassi, U. (2021). Alkali-activated adsorbents from slags: Column adsorption and regeneration study for nickel(II) removal. ChemEngineering, 5(1), 13. https://doi.org/10.3390/chemengineering5010013 https://doi.org/10.3390/chemengineering5010013 Rinnakkaistallennettu versio Sundhararasu, E., Runtti, H., Kangas, T., Pesonen, J., Lassi, U., & Tuomikoski, S. (2022). Column adsorption studies for the removal of ammonium using Na-zeolite-based geopolymers. Resources, 11(12), 119. https://doi.org/10.3390/resources11120119 https://doi.org/10.3390/resources11120119 Rinnakkaistallennettu versio Sundhararasu, E., Runtti, H., Kangas, T., Lassi, U., & Tuomikoski, S. (2025). Slag-based alkali-activated adsorbent for efficiently removing ternary heavy metals and dye in wastewater. Manuscript in preparation. Academic dissertation to be presented with the assent of the Doctoral Programme Committee of Technology and Natural Sciences of the University of Oulu for public defence in the Arina auditorium (TA105), Linnanmaa, on 4 December 2025, at 12 noonAbstract
Industrial wastewater contains harmful contaminants like ammonium, heavy metals (e.g. nickel, cobalt, zinc), and cationic dyes (e.g. methylene blue), posing environmental and health risks. This study develops cost-effective, eco-friendly alkali-activated adsorbents for wastewater treatment from industrial side-streams (analcime and steel industry slags), activated with sodium hydroxide and sodium silicate or potassium silicate. Experiments were designed to assess the effectiveness of these adsorbents in removing wastewater pollutants. Initially, the efficiency of removing ammonium ion pollutants from aqueous solutions was tested, and the results (29.79 mg/g) were used as guidance in refining the synthesis conditions of the adsorbents to optimize their structural and chemical properties to ensure more effective adsorption capacities. The batch experiments demonstrated the rate of ammonium ions captured by the adsorbent surface and the interaction between the adsorbent and ammonium ions provides insight into the efficiency of the process under controlled experimental conditions.
Continuous fixed-bed column studies were then conducted to investigate the performance of the adsorbents under various conditions and to simulate practical wastewater treatment scenarios and evaluate the effectiveness of a continuous flow system. The fixed-bed columns demonstrated the adsorption behavior of multiple contaminants and the adsorption capacity was 3.26 mg/g, 13.92 mg/g, 6.86 mg/g, 6.39 mg/g and 18.9 mg/g for ammonium, zinc, cobalt, nickel and cationic dyes, respectively. The results showed that alkali-activated adsorbents were highly effective among the pollutants studied. The adsorbents´ reusability was evaluated by a regeneration study and the results confirmed their pollutant removal capacity over different cycles. Adsorbents preserved their pollutant removal capacity over successive regeneration experiments. This demonstrated stability highlights their potential for repeated use in continuous wastewater treatment operations and illuminates their economic and environmental advantages. Overall, the findings validated the effectiveness of alkali-activated adsorbents synthesized from industrial side-streams in wastewater treatment.Tiivistelmä
Teollisuuden jätevedet sisältävät haitallisia epäpuhtauksia, kuten ammoniumia, raskasmetalleja (esim. nikkeli, koboltti, sinkki) ja kationisia väriaineita (esim. metyleenisininen), jotka aiheuttavat ympäristö- ja terveysriskejä. Tässä tutkimuksessa kehitettiin kustannustehokkaita ja ympäristöystävällisiä alkaliaktivoituja adsorbentteja jäteveden käsittelyyn hyödyntämällä teollisuuden sivuvirtoja (analsiimi ja terästeollisuuden kuonat). Kokeissa testattiin adsorbenttien tehokkuutta jäteveden epäpuhtauksien poistamisessa. Aluksi testattiin ammoniumionien poistotehokkuutta vesiliuoksista ja tulosten (29,79 mg/g) pohjalta muokattiin adsorbenttien synteesiolosuhteita niiden rakenteellisten ja kemiallisten ominaisuuksien optimoimiseksi tavoitteena parantaa materiaalin adsorptiokykyä. Panoskokeet osoittivat nopean ja tehokkaan ammoniumin adsorboinnin kontrolloiduissa koeolosuhteissa.
Kolonnikokeet simuloivat käytännön olosuhteita jätevedenpuhdistuksessa. Kolonnikokeet osoittivat useiden epäpuhtauksien, kuten ammoniumionien, raskasmetallien ja kationisen väriaineen, poistotehokkuuden. Adsorptiokapasiteetti oli 3,26, 13,92, 6,86, 6,39 ja 18,9 mg/g ammoniumin, sinkin, koboltin, nikkelin ja väriaineen poistossa. Adsorbenttien uudelleenkäytettävyys arvioitiin regenerointitutkimuksella. Tulokset vahvistivat adsorbentin epäpuhtauksien poistokapasiteetin useilla adsorptio-desorptiosykleillä. Adsorbentit säilyttivät epäpuhtauksien poistokykynsä peräkkäisten regenerointikokeiden aikana. Adsorbentin käytettävyys useissa sykleissä osoittaa taloudellisia ja ympäristöllisiä etuja.
Yhteenvetona tutkimus vahvistaa, että teollisuuden sivuvirroista syntetisoidut alkaliaktivoidut adsorbentit ovat tehokas ratkaisu jäteveden käsittelyyn. Adsorptiokyky ammoniumille, raskasmetalleille ja väriaineille oli suuri. Näiden tulosten ohella adsorbenttien tehokas regenerointi osoitti mahdollisuudet teollisuuden jätevesien käsittelyyn ympäristöystävällisellä ja kustannustehokkaalla tavalla
Alkali-activated materials containing mine tailings and zeolite for seepage water treatment in a closed nickel mine
Get PDFIn the present study, alkali-activated materials were assessed as adsorbents for mine water treatment. The composition of alkali-activated materials, involving mixtures of metakaolin, blast-furnace slag, mine tailings, and zeolite, was optimized based on their leaching behavior and adsorption performance. The most effective adsorbent contained solely blast furnace slag as an aluminosilicate precursor and was selected for a pilot-scale study at a closed nickel mine in Finland. In the pilot, seepage water from a gangue area with an influent flow rate of 0.5 m3/d was treated using a permeable reactive barrier set-up containing 10 kg of slag-based adsorbent prepared by a granulation-alkali activation process. During a one-week experiment, the adsorbent granules were capable of effectively uptaking Ni, Fe, and Mn from the seepage water; the removal percentages of Ni, Fe, and Mn were 82.4%, 81.6%, and 82.5%, respectively. The results indicated the feasibility of blast furnace slag-based adsorbents for toxic element removal in a potentially sustainable approach
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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