Carbon dioxide (CO2 )gases that dominated by anthropogenic activities causevarious negative impacts on the environment and surroundings due to increasing itsconcentrations in the atmosphere. There are some techniques to mitigate againstthe increase of CO2 which one is the utilization of phytoplankton cultured in a photobioreactor (FBR) as an natural absorber. In this study, the influence of input gas CO2flowrate on Chlorella sp at multiple tubular air lift photobioractor (FBR) was measuredin milk factory field. The CO2 flowrate continuesly was controled by 2 l/min and 1.5 l/mduring experiment. Result showed that Chlorella sp. have a good adapted ability of CO210-15% vol industrial emition. The experiment result stated that reactor capability atFBR-1 was lower than FBR-2. The reactor capability at FBR-1 and FBR 2 were 0,78 ±0,25 and 0,92 ± 0,36 g/l. media/day.

This study investigates the feasibility of microalgae cultivation with the effluent (permeate) of a decentralized anaerobic membrane bioreactor (AnMBR) treating high strength domestic wastewater. Two experiments, consisting of three and two successive batch experiments with incubation times varying between 5 and 9 days, were conducted. Nutrient removal and growth of the microalgae species Acutodesmus obliquus were studied for the following culture media: (A) permeate, (B) permeate enriched with iron (Fe), magnesium (Mg), manganese (Mn), sulfur (S) and the chelating agent EDTA, (C) commercial fertilizer as control culture. Initial nutrient concentrations in the culture media ranged from 9.3 to 16.6 mg·L−1 total phosphorus (TP) and from 85.1 to 126.2 mg·L−1 total nitrogen (TN). TP reached an average removal of 97%, 98% and 99% in (A), (B) and (C) respectively. An average TN removal of 94% and 96% was achieved in (B) and (C). Starting from the third batch of the first experiment and the second batch of the second experiment, the culture with permeate (A) showed a decrease in TN removal. Further batch experiments showed the need to add iron to ensure an optimal TN removal from the permeate.

Review of Virus Inactivation Technologies for Covid-19 Pandemic Control SARS-CoV-2 virus inactivation is one of global concerns in alleviating the spread of Covid-19. The applications of virus inactivation technologies are mainly based on the knowledge of virus characteristics, its persistence on material surfaces, and environmental factors impairing its structure. Current virus inactivation methods are mostly employing chemicals dan physical treatments such as hydrogen peroxide, hypochlorite solutions, and UV light. In this paper, we discuss three current virus inactivation technologies for reducing the spread of Covid-19, i.e., room disinfection, surface disinfection, and personal protective equipment (PPE) decontamination technology. Room disinfection technology, particularly room with poor ventilation or closed air circulation, employs the combination of UV light treatment with filters. Surface disinfection technologies utilize the spraying or fogging of disinfectant solutions, and PPE decontamination technologies utilize UV light or chemical treatments to inactivate the virus. Further development and application of these technologies will help the national effort in controlling the spread of Covid-19. Inaktivasi virus SARS-CoV-2 merupakan salah satu upaya global untuk mengurangi penyebaran Covid-19. Aplikasi teknologi inaktivasi virus ini banyak bersandar pada pengetahuan mengenai karakteristik dan daya tahan virus ini pada permukaan benda dan hal-hal yang merusak struktur virus tersebut. Metode inaktivasi virus yang banyak digunakan adalah perlakuan dengan bahan kimia dan perlakuan secara fisik yaitu dengan menggunakan larutan disinfektan hidrogen peroksida, larutan hipoklorit dan sinar UV. Dalam tulisan ini, peluang aplikasi teknologi inaktivasi virus SARS-CoV-2 yang dibahas adalah teknologi disinfeksi ruangan, disinfeksi permukaan benda dan dekontaminasi alat pelindung diri. Teknologi disinfeksi ruangan khususnya pada ruangan tertutup dengan ventilasi yang kurang baik atau resirkulasi udara tertutup adalah dengan menggunakan kombinasi perlakuan sinar UV dengan filter. Teknologi disinfeksi permukaan benda menggunakan teknik penyemprotan atau pengkabutan larutan disinfektan, sedangkan teknologi dekontaminasi alat pelindung diri dilakukan dengan perlakuan sinar UV atau dengan bahan kimia. Pengembangan dan aplikasi lanjut dari teknologi inaktivasi virus ini akan membantu upaya nasional dalam penanggulangan penyebaran Covid-19.

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The microalgae incorporated photobioreactor (PBR) is a highly efficient biological system for converting carbon dioxide (CO2) gases into biomass and treating wastewater. In this study, the freshwater microalgae Chlorella sp. was cultured in two unit photobioreactors which were connected to a boiler of dairy factory. The source of water for microalgae culture media (in the photobioreactors) are collected from the waste water treatment plant of the dairy factory itself. The objective of this microalgae photobioreactor activity were to reduce CO2, produce biomass and as a part of a waste water treatment in a dairy industry in Indonesia. Both photobioreactors were operated for 14 days culture interval in the semi continuous cultivation, with initial stocking rate of 2 x 105 cells/ml microalgae. Carbon dioxide concentration from the boiler stack was 10-11 % vol. The photobioreactors were injected with the specified CO2 concentration with flow rate of 2 l/min. and 1.5 l/min. The result showed that microalgae photobioreactors capability in CO2 absorption were 0.78 ± 0.25 and 0.92 ±0.36 g CO2/l media/day, respectively. Before and after utilized by the photobioreactors system, Nitrate and Phosphate concentration of the culture media (supplied from the waste water treatment plant) decreased from 3-4 mg/l to 0.05-0.1 mg/l. After 14 days cultivation, biomass concentration of microalgae which were injected with CO2 flow rate of 2 l/min. and 1.5 l/min. were 19 x 106 cells/ml and 15 x 106 cells/ml respectively. Results showed that microalgal photobioreactors operated in an industrial area could reduce CO2 concentration and produce biomass.Keywords: photobioreactor (PBR), Chlorella sp., CO2 flue gas emissions, wastewater