4:00 PM - 4:15 PM
[AGE28-08] Applicability of granulated autoclaved aerated concrete for the removal of dispersed oil in wastewater
Keywords:Autoclaved aerated concrete, dispersed oil, wastewater treatment
Tesshin Fujisaki(041947) 1, Akihiro Matsuno(019778) 1, and Ken Kawamoto (015049)1
1 Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama-shi, 338-8570 JAPAN
Keywords: Autoclaved aerated concrete, dispersed oil, wastewater treatment, reuse and recycling
The emission of domestic and industrial wastewater is increasing due to rapid population growth, urbanization, and industrialization in many developing countries in Vietnam. In 2016, for example, an oil spill accident occurred in a 200-km coastal area in the central coastal region of Vietnam caused a huge environmental damage and outbreak of fish mortality. It has been also reported many surface and coastal waster have been polluted exceeding the environmental standards. As well as the rapid economic growth, on the other hand, the discharge of solid waste including cconstruction and demolition waste (CDW) is increasing, and it reaches approximately 12% of total solid waste generation (~ 60,000 tons/day in 2019) in Vietnam. Till now, however, the generated CDW is not fully reused and recycled, and the CDW is directly used landfilling without treatment or dumping at vacant lands, ponds, and riverbanks. This study aimed the effective reuse of autoclaved aerated concrete (AAC) waste and scrap among of CDW in Vietnam and investigated the applicability for the removal of dispersed oil in wastewater. The AAC can be expected to be a good ability as an adsorbent to remove dispersed oil in wastewater because it has well-porous structure with a high specific surface. First, the AAC waste was crushed and sieved to prepare granulated AAC (size: 0.106-0.25, 0.25-0.85, and 0.85-2 mm). To promote the sorption of dispersed oil, not only raw granulated AAC but also the granulated AAC coated with hydrophobic/oleophilic agents (oleic acid and stearic acid) were used as adsorbents. For examining the removal of dispersed oil in wastewater, synthetic dispersed oil solutions with different initial concentration ranging from 10 to 1000 mg/L were prepared by dispersing soybean oil in distilled water in the laboratory (oil droplet size < 2 μm). A batch adsorption tests were carried out and removal percent was calculated by measuring the oil concentration in the adsorbent after the tests. The results showed that for both non-coated and coated granulated AAC removed well dispersed oil in water, in especial, granulated AAC coated with oleic acid of 1 g/kg and with stearic acid of 10 g/kg gave high removal percents (> 70 %) for all initial oil concentration solutions. This suggests that the granulated AAC is highly applicable to treat oily wastewater and it contributes the effective reuse and recycling of AAC waste and scrap.
1 Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama-shi, 338-8570 JAPAN
Keywords: Autoclaved aerated concrete, dispersed oil, wastewater treatment, reuse and recycling
The emission of domestic and industrial wastewater is increasing due to rapid population growth, urbanization, and industrialization in many developing countries in Vietnam. In 2016, for example, an oil spill accident occurred in a 200-km coastal area in the central coastal region of Vietnam caused a huge environmental damage and outbreak of fish mortality. It has been also reported many surface and coastal waster have been polluted exceeding the environmental standards. As well as the rapid economic growth, on the other hand, the discharge of solid waste including cconstruction and demolition waste (CDW) is increasing, and it reaches approximately 12% of total solid waste generation (~ 60,000 tons/day in 2019) in Vietnam. Till now, however, the generated CDW is not fully reused and recycled, and the CDW is directly used landfilling without treatment or dumping at vacant lands, ponds, and riverbanks. This study aimed the effective reuse of autoclaved aerated concrete (AAC) waste and scrap among of CDW in Vietnam and investigated the applicability for the removal of dispersed oil in wastewater. The AAC can be expected to be a good ability as an adsorbent to remove dispersed oil in wastewater because it has well-porous structure with a high specific surface. First, the AAC waste was crushed and sieved to prepare granulated AAC (size: 0.106-0.25, 0.25-0.85, and 0.85-2 mm). To promote the sorption of dispersed oil, not only raw granulated AAC but also the granulated AAC coated with hydrophobic/oleophilic agents (oleic acid and stearic acid) were used as adsorbents. For examining the removal of dispersed oil in wastewater, synthetic dispersed oil solutions with different initial concentration ranging from 10 to 1000 mg/L were prepared by dispersing soybean oil in distilled water in the laboratory (oil droplet size < 2 μm). A batch adsorption tests were carried out and removal percent was calculated by measuring the oil concentration in the adsorbent after the tests. The results showed that for both non-coated and coated granulated AAC removed well dispersed oil in water, in especial, granulated AAC coated with oleic acid of 1 g/kg and with stearic acid of 10 g/kg gave high removal percents (> 70 %) for all initial oil concentration solutions. This suggests that the granulated AAC is highly applicable to treat oily wastewater and it contributes the effective reuse and recycling of AAC waste and scrap.