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Combining adsorptive activated carbon and catalytic oxidative cerium oxide, an adsorptive catalyst could be synthesized. Cerium oxide impregnated on activated carbon had been utilized in various gas pollutant removal technologies. In this study, impregnation of cerium oxide and sodium hydroxide on palm shell activated carbon (PSAC) was attempted to produce an adsorbent for H 2 S removal from biogas produced in palm oil industry. Effects of preparation parameters of CeO 2 /NaOH/PSAC towards H 2 S removal were successfully studied. The studied parameters were impregnation time, cerium amount, NaOH concentration, calcination temperature and calcination time. From the study, it was found that every parameter can be optimized because there was a value of the parameter that resulted in a maximum adsorption capacity. The optimum preparation parameters of CeO 2 /NaOH/PSAC were found to be 1.5 h impregnation time, 5% cerium, 1.0 M NaOH, 400 °C calcination temperature and 3 h calcination time. Selected adsorbents were characterized in order to further understand adsorbent properties and characteristics of the reaction. [ABSTRACT FROM AUTHOR]

There has been an increase in the amount of focus placed on microalgae-based technology in recent years, due to its great performance in wastewater treatment, nutrient restoration, and manufacture of alternative biofuels or other high-value commodities. However, the difficulties of harvesting biomass hinder the deployment of microalgae-based technology for continuous wastewater treatment and resource recovery. This article analysed the worldwide dynamics of microalgae bio-granulation research from 2011 to 2023 based on a bibliometric analysis of 250 publications extracted from the Scopus database. The research progression, prominent contributors in the subject, and latest developments and research gaps were determined using the Scopus database. The results show a rapid increment in the annual publications, with China as the most active nation in this study field, followed by India, United State, Taiwan, Japan, South Korea and Malaysia. The research trend in microalgae bio-granulation show most research focusing on the incorporation of microalgae-bacteria symbiosis for granulation. However, there are almost no research on development of denser single-species microalgae granules without bacteria for easy harvesting via self-flocculation. Besides that, till today there are no study that investigate the effect of organic nutrient (glucose) and inorganic nutrient (sodium bicarbonate) on microalgae granulation. In addition, there are lack of studies use Chlorella Vulgaris microalgae species in bio-granulation process. An outline of possible future research was given, with a focus on technology used, nutritional media and environmental studies, and the microorganism selection. • Development of denser single-species microalgae granules without bacteria for rapid harvesting by self-flocculation. • Effect of organic and inorganic nutrients on the microalgae granules growth. • Enrichment of Chlorella vulgaris sp. microalgae via bio-granulation method for wastewater treatment. [ABSTRACT FROM AUTHOR]

This study aims to produce biochar and sugars from a macroalga Eucheuma denticulatum using dilute sulfuric acid hydrolysis along with microwave-assisted heating. The reactions were operated at sulfuric acid concentrations of 0.1 and 0.2 M, reaction temperatures of 150–170 °C and a heating time of 10 min. Compared to the raw macroalga, biochar qualities were improved with increased carbon content and lower ash and moisture contents. The calorific value of the biochar could be intensified up to 45%, and 39% of energy yield was recovered. Apart from producing biochar, the highest total reducing sugars were 51.47 g/L (74.84% yield) along with a low by-product 5-HMF of 0.20 g/L, when the biomass was treated under the optimum conditions at 160 °C with 0.1 M H 2 SO 4 . Thus, this study demonstrated that macroalgae could be potentially used as biomass feedstock under microwave-assisted acid hydrolysis for the production of biofuel and value-added products. [ABSTRACT FROM AUTHOR]

Significant development in conversion technologies to produce bioethanol from microalgae biomass is causing paradigm-shift in energy management. In this study, carbohydrate-rich microalgae, Scenedesmus dimorphus (49% w/w of carbohydrate) is selected with the aim to obtain qualitative correlation between pretreatment and fermentation process. In view of this, separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) were conducted experimentally. The fermentation behavior were investigated for microalgae biomass treated via organosolv, enzymatic and acidic pretreatment. Fermentation process was carried out by ethanologen microbe, Saccharomyces cerevisiae . From the result, it is observed that a combination of two treatment is found to be the most effective in producing fermentable sugar for the subsequent fermentation process. The organosolv treatment which is followed with the SSF process produced a theoretical yield of bioethanol that exceeded 90%. On the other hand, hydrothermal acid-hydrolyzed fermentation produced the bioethanol yield with 80% of its theoretical yield. Enzymatic-hydrolyzed SHF produced 84% of theoretical yield at longer reaction time compared with others. The results were obtained with constant fermentation parameters conducted at pH 5, temperature of 34 °C, and microalgae biomass loading at 18 g/L. Ultimately, the coupling of organosolv-treated biomass with SSF process is found to be the most cost-effective for S. dimorphus biomass as bioethanol feedstock. [ABSTRACT FROM AUTHOR]