Aerobic granulation is increasingly used in wastewater treatment due to its unique physical properties and microbial functionalities. Granule size defines the physical properties of granules based on biomass accumulation. This study aims to determine the profile of size development under two physicochemical conditions. Two identical bioreactors namely Rnp and Rp were operated under non-phototrophic and phototrophic conditions, respectively. An illustrative scheme was developed to comprehend the mechanism of size development that delineates the granular size throughout the granulation. Observations on granules' size variation have shown that activated sludge revolutionised into the form of aerobic granules through the increase of biomass concentration in bioreactors which also determined the changes of granule size. Both reactors demonstrated that size transformed in a similar trend when tested with and without illumination. Thus, different types of aerobic granules may increase in size in the same way as recommended in the aerobic granule size development scheme.

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Major concern about the presence of fluoranthene, which consists of four fused benzene rings, in the environment has been raised in the past few years due to its toxic, mutagenic, and persistent organic pollutant properties. In this study, we investigated the removal of fluoranthene under static and agitated conditions. About 89% fluoranthene was removed within 30 days under the agitated condition, whereas under the static condition, only 54% fluoranthene was removed. We further investigated the behavior and mechanism of fluoranthene biosorption and biotransformation by Pleurotus eryngii F032 to accelerate the elimination of fluoranthene. The optimum conditions for the elimination of fluoranthene by P. eryngii F032 included a temperature of 35 °C, pH 3, 0.2% inoculum concentration, and a C/N ratio of 16. Under these conditions at the initial fluoranthene concentration of 10 mg/L, more than 95% of fluoranthene was successfully removed within 30 days. Of those factors influencing the biodegradation of fluoranthene, salinity, glucose, and rhamnolipid content were of the greatest importance. Degradation metabolites identified using gas chromatography-mass spectrometry were 1-naphthalenecarboxylic acid and salicylic acid, suggesting possible metabolic pathways. Finally, it can be presumed that the major mechanism of fluoranthene elimination by white-rot fungi is to mineralize polycyclic aromatic hydrocarbons via biotransformation enzymes like laccase.

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The production and consumption of biohydrogen is growing because it is a “green,” renewable energy that can be obtained in a relatively cost‐effective manner through anaerobic digestion. Biohydrogen produced from biomass is a viable source of renewable energy; nevertheless, the presence of highly toxic and corrosive hydrogen sulfide (H2S) in the process can hinder the quality of biohydrogen production and limit its application in energy conversion equipment. Consequently, the goal of the research was to assess the feasibility of using ZSM‐5 zeolite for H2S adsorption that function as activating agent to enhance biohydrogen quality under thermophilic conditions. The effect of ZMS‐5 Zeolite loading (0.2–1.0 g) on biohydrogen production via dark fermentation from mixed fruit waste (MFW) was investigated using anaerobic sludge from a sewage treatment plant. The pH of the broth mixture was adjusted to 6.0, anaerobic conditions were created by purging it with nitrogen gas, and the temperature of the fermentative biohydrogen process was maintained at 60°C. Meanwhile, the H2S adsorption test was run at ambient temperature with flow rates (100 ml/min) and an H2S inlet concentration of 10000 ppm. The results indicate that the Z + H2S exhibit spectral lines corresponding to the S‐H asymmetric stretching vibration of H2S at 2345.97 cm−1. The ideal adsorption capacity is at 0.8 g with yet, increasing the dosage amount of adsorbents, increases the time required for the adsorbent to achieve 90% saturation. The non‐linear curve fitting demonstrated that the adsorption kinetics of all dosages used followed those of the Avrami kinetic model. This approach of using ZSM‐5 zeolite for H2S removal provides an advantage in terms of minimizing environmental pollution and having great potential uses in industrial processes.