In this study, a comprehensive comparison of two different chemical pretreatments of wheat straw (WS) and rice straw (RS) was made. The pretreatment was performed using piranha solution and p-toluenesulfonic acid (PTSA) to dissolve the biomass’s complex lignin and hemicellulose matrix to enhance its methane production. Energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopes (SEM), and X-ray diffraction (XRD) analysis, were used to analyze the characteristics of untreated and pretreated feedstock. WS and RS treated with piranha solution showed maximum methane yield (1234 mL and 1196 mL, respectively). The piranha pretreatment increased the methane yield of wheat straw by 2.37 folds and rice straws by 2.31 folds. The maximum VFA concentration was observed in WS on the 14th day in the piranha-treated sample, 1553.33 ± 2.8 mg.L-1, while in RS on the 21st day in the untreated sample, 676 ± 5.77 mg.L-1. SEM analysis of piranha-treated WS indicated a reduction in recalcitrant structure. Deformation of C-O, C=C, C-C-O, and C-H bonds in cellulose, hemicellulosic, and lignin as a result of chemical pretreatment in WS and RS was also indicated by FTIR analysis. The modified Gompertz model (MGM) and logistic function model (LFM) appropriately defined the degradation process and explained cumulative biogas’ kinetic. Pretreatment with piranha solution reduces the complexity of WS and RS, thus increasing methane production by reducing the retention time.

Spatial data technology using unmanned aerial vehicle (UAV) is one of the aerial imaging technologies used to produce detailed data. However, its utilization for mapping, especially disaster mapping needs an in-depth study. The research site is located within 00-”00’29°51’31°00” N and 12327’5°-123”00’3°” E that covers an area of 2,531 Ha, which consists of 1,745 Ha land and 786 Ha water areas. Administratively, the research site is in South Leato Village of Dumbo Raya sub-district of Gorontalo city with a total area of 41,9 Ha. This study is aimed at assessing the landslide by creating a landslide zonation map and finding out the landslide potential area by using the UAV. This research employs field surveys by using drones and Geographic Information System (GIS) analysis. It is found that the parameters that influence landslides are lithology, rainfall, slope inclination, lineament density, and land use. The landslide vulnerability analysis reveals three levels of vulnerability in this site; low, medium, and high vulnerability, in which, 19 Ha is classified as low vulnerability area, 9.5 Ha is classified as medium vulnerable, and 13.5 Ha is classified as highly vulnerable area.

Using granular form application in the pisciponic system, this study investigates the effects of supplementation in the pisciponic system on plant growth performance. This study was conducted at the Aquaculture Experimental Station in Puchong, Selangor. The experiment was set up in a greenhouse with a plastic liner at the bottom. The coated fertilizers were immersed in 500 mL of distilled water in the beakers. The immersion times were analyzed for each 3, 6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, and 72 hours. Insoluble solids and water were then filtered using filter paper and dried in the oven, followed by the drying process to obtain a constant weight before being put in the desiccators. During the release test, the distilled water was taken at every 48-hour interval, and the concentration of nutrients was determined from the atomic absorption spectrometer. The findings indicate that the weights of release fertilizers, specifically Zn and Fe, significantly decreased over time. At the lowest concentration, the coated zinc and iron weights decreased as time increased. Referring to the curve results, the Zn fertilizer started drastically decreasing its weight at hour 24, which decreased approximately to 0.002 for every subsequent hour. Meanwhile, Fe fertilizer decreased drastically at hour 66, where the weight dropped from 0.10467 to 0.039. However, the final weights for both fertilizers at hour 72 were about the same.

Heavy metals can decrease the number of species in nature. This research aims to determine the relationship between the type of macroinvertebrates stressed by heavy metals in the Wonorejo Mangrove Area, Surabaya, East Java. This type of research is observational. The determination of stations was done using the purposive random sampling method. Tests for Pb and Cd content were carried out using the AAS method. Nutrient content testing was carried out using the AAS and Kjeldahl methods. Data analysis was presented descriptively, and multivariate analysis was done using Principal Component Analysis (PCA). Based on the present research, it can be concluded that there are variations in the type and distribution of macroinvertebrates stressed by heavy metals in the mangrove area of Surabaya. Station 1 is dominated by Ocypode ryderi, Station 2 by Assiminea sp., Station 3 by Scylla paramamosain, and Station 4 by Cerithidea sp. with the high presence of metals (Cd, Pb), and soil and water nutrients (Org-C, N) at Stations 1, 3, and 4. The Station 2 has only Pb. Assiminea sp. (Phylum Mollusca) can be the best candidate for metal bioindicators because it appears in all locations where soil and water have been contaminated with Pb and Cd metals without affecting their life.

This study explains visitors’ perceptions of climate comfort in the Padang coastal tourism area, including Air Manis Beach, Padang Beach, Nirwana Beach, and Pasir Jambak Beach. Climate comfort index calculation using the Holiday Climate Index (HCI) and survey methods are used to take data. The survey is conducted to collect data on climate comfort perception and the role of weather on that comfort. There are 409 respondents in this study. Most visitors state that weather affects climate comfort during their trip (99%) and need weather information for outdoor tourism (98.5%). However, only 27.1% are looking for weather information before traveling outdoors. This coastal tourism area’s perceived level of climate comfort is comfortable (64%). The thermal sensation is neutral (66%). Meanwhile, the average score of the comfort index in Padang is neutral throughout the year. The temperature interval indicates the comfortable category is between 26ºC-28ºC.

Extreme floods have become common in Asian cities, with recent increases in urbanization and extreme rainfall driving increasingly severe and frequent events. Understanding the flood dynamic is essential for developing strategies to reduce risk and damage, thus ensuring the city’s protection. Channel roughness is a sensitive parameter in developing a hydraulic model for flood forecasting and flood inundation mapping. A High-resolution 2D HEC-RAS model was used to simulate the flood events of 1994, 1998, 2002, 2006, and 2015. The calibrated model, in terms of channel roughness, has been used to simulate the flood for the year 2006 in the river. The performance of the calibrated HEC-RAS-based model has been accessed by capturing the flood peaks of observed and simulated floods and computation of root mean squared error (RMSE) for the intermediated gauging stations on the lower Tapi River. Results revealed that there is good agreement between simulated and observed floods.

The present study collected anaerobic sludge from a paper mill operating a UASB reactor on agro-based raw material (wheat straw) washings for biogas production. After determining the sludge profile and methanogenic activity of anaerobic sludge, it was further used to determine the anaerobic biodegradability of RCF-based kraft paper mill effluent. The sludge profile of collected anaerobic sludge was found w.r.t. Suspended Solids (SS) 60 g.L-1, Volatile Suspended Solids (VSS) 23 g.L-1, Inorganic content 62% & Organic content 38%. The presence of effective microbes in anaerobic sludge was confirmed by SEM (Scanning Electron Microscope). Degradation of organic matter present in effluent by anaerobic digestion leads to the production of biogas (methane & CO2), a renewable energy source. The sludge profile and methanogenic activity findings supported the anaerobic treatment of kraft paper mill effluent and were positive. The methanogenic activity of anaerobic sludge was determined as 0.832 gCOD.gVSS-1×Day, and the average anaerobic biodegradability of RCF-based kraft paper mill effluent was found to be 71.5%.

In the present study, a total of 17 morphologically different gut-associated bacteria were isolated from four species of estuarine polychaetes: polychaetes Capitella capitata, Scalibregma inflatum, Dendronereis aesturiana, and Namalycastis abiuma. The isolated strains were evaluated for their probiotic activities, such as digestive enzymes including protease, amylase, and lipase, and antimicrobial activities by the agar well diffusion method against fish pathogens. Based on their better enzymatic and antibacterial activities, two bacterial strains, CMST Poly1 and CMST Poly2, were selected for further probiotic studies. Based on the biochemical and morphological characterization, both probiotic strains were characterized as Gram-positive, rod-shaped, non-motile, non-spore-forming, homofermentative, absence of catalyzing enzymes and notable proteolytic activity, and susceptibility to various antibiotics. Further, these two strains were confirmed by 16S rRNA gene sequence analysis as Bacillus subtilis CMST Poly1 and Priestia megaterium CMST Poly2. Our results revealed that strains Bacillus subtilis CMST Poly1 and Priestia megaterium CMST Poly2 can potentially be used as probiotic strains in aquaculture applications.

Good quality activated charcoals were prepared from areca nutshell and coconut shell using phosphoric acid as a chemical activating agent at 400oC. Physico-chemical properties like iodine number, methylene blue number, and surface area of two activated charcoals were measured to assess the porous nature. A special test called acetic acid number was devised to understand the quality of functional groups on charcoal surfaces. Proximate analysis and physical properties of the two activated charcoals closely matched those of a commercial sample, confirming the good quality of samples prepared in the laboratory. Adsorption of isolated caramel from waste stream obeyed Freundlich isotherm, and the data could be explained based on the physisorption of large size molecules on the walls of mesoporous solid surface. Adsorption of methylene blue involving Coulombic attraction towards the areca nut shell-derived activated charcoal could be predicted and confirmed based on the acetic acid number for the first time.

Globally, with an increase in population, water demand is also increasing, but on the other hand, water availability is continuously decreasing due to various factors. Contamination of existing water bodies is the main factor for the freshwater shortage. Conventional methods are there to treat polluted water, but their construction and operational cost are very high. Phytoremediation is an economical, solar-driven, green plants (macrophytes) based, environment-friendly technology being researched worldwide. Many researchers contributed to identifying the potential of phytoremediation to treat different types of wastewater. Along the same line, an attempt has been made with this literature survey to contribute to technological advancement. The study results showed that water hyacinth plants could potentially treat almost all types of wastewater. Still, their use with other plants like Phragmites australis, Azolla filiculoides, Lemna minor, Typha latifolia, etc., as polyculture (mixed culture) could perform way better than the individual. It not only improves the efficiency of phytoremediation but also helps some plants to grow and perform for a long duration when used in mixed culture.