2 research outputs found
Geopolymer lightweight bricks manufactured from fly ash and foaming agent
This paper deals with the development of lightweight geopolymer bricks by using foaming agent and fly ash. The mix parameters analysed through a laboratory experiment with fix ratio of sodium silicate/sodium hydroxide solution mass ratio 2.5, fly ash/alkaline activator solution mass ratio 2.0, foaming agent/paste mass ratio 1:2 and molarity of sodium hydroxide solution used was 12M. Different curing temperature (Room Temperature, 60, 80) and foaming agent/water mass ratio (1:10 and 1:20) were studied. Compressive strength, density analysis, and water absorption has been investigated. The results show that the foamed geopolymer bricks with a lower foam/water mass ratio (1:10)and high curing temperature (80°C) leading to a better properties. Mixtures with a low density of around 1420 kg/m3 and a compressive strength of around 10 MPa were achieved
The phytoremediation using water hyacinth and water lettuce : correlation between sugar content, biomass growth rate, and nutrients
Degradation of water quality due to the presence of pollutants in water is an emerging issue in many countries, including
Malaysia. Phytoremediation is one of the environmentally friendly, cost-effective conventional technologies that are
still used in modern times. However, the selection of plant species is the most important aspect for the application of
phytoremediation in wastewater treatment. Nevertheless, there are species of floating aquatic macrophytes that are capable
of coping with various pollutants present in wastewater. Among the various floating aquatic macrophyte species, water
hyacinth (WH) and water lettuce (WL) have been described as effective phytoremediators in reducing water pollution through
bioaccumulation in their body tissues. Hence, WH and WL were chosen in this study as it is easily found, propagated,
and cultivated. This paper aims to determine the biosorption capacity of these species in eliminating various pollutants
present in wastewater as well as to define the optimum harvesting time for each species. Although these floating aquatic
macrophytes are considered the most problematic plants due to their uncontrollable growth in water bodies worldwide,
their ability to remove pollutants from wastewater has created a sustainable approach for their use in phytoremediation.
In this sense, the use of phytoremediation by implementing the invasive floating aquatic macrophytes can certainly support
the sustainable management of wastewater treatment in the future. Based on the results, it was found that WH efficiently
removed higher PO4
3-, NO3
-
and NO2
-
concentrations compared to WL from the wastewater. Both WH and WL showed the
same trend of correlation between the growth rate and sugar content, where the sugar content increased when the plants
reached the highest growth rate. The maximum nutrient uptake occurred in 14-17 days, proving that nutrient availability is
critical for plant growth. This study concludes that the sugar content of WH and WL are increased with the biomass growth
rate, and both plants species are competent in eradicating the nutrient pollution in wastewater. On top of that, this study
infers that the maximum harvesting period for WH biomass is on day 18, while WL biomass is on day 21; based on the
highest sugar content and biomass weight of each species