The outbreak of coronavirus diseases (COVID-19) receives much attention globally. On January 30, 2020, WHO has stated it was a global health emergency. The Indonesian Government requiring that all work from home and restricting access to activities outside the home. In the Bali Province, it has had a positive impact on the environment, especially for the amount of waste generation and emissions. The main objectives of this study were to analyse solid waste generation and to provide a review of issues in environmental impact during and before the pandemic of COVID-19 in Bali Province. LCA technique has been used extensively to evaluate the environmental performance of several municipal solid waste management technologies. An LCA study consists of four stages, such as goal and scope, life cycle inventory, life cycle impact analysis, and interpretation. The degraded organic carbon (DOC) value before the pandemic was 0.121 while after the pandemic the DOC reduced to 0.058. Moreover, methane and carbon dioxide production from waste generation per day was counted in this study. The total global warming potential from waste generation has been drastically reduced from 1,859.6 kg CO 2eq /day to 420.8 kg CO 2eq /day.

The purpose of this research is to investigate wastewater treatment with ozone pretreatment and post-treatment integrated with Moving Bed Biofilm Reactor (MBBR). Ozonation as a pre-treatment served to increase the Biochemical Oxygen Demand (BOD)/Chemical Oxygen Demand (COD) ratio while as a post-treatment to remove the remaining organic residues. Ozone doses were 1 mg/min, 4 mg/min, 20 mg/min, and 40 mg/min. In the pre-treatment, ozone produced a BOD/COD value of 0.68. The MBBR process had a COD and color removal efficiency of 68.89% and 67%, respectively. In the MBBR process without ozone pre-treatment, the efficiency of COD and color removal were 79.31% and 64.7%, respectively. The effluent treatment results from MBBR were then processed with ozone and showed the highest COD and color removal results of 76.8% and 99%, respectively. In this study, the processing with ozone as post-treatment was better than the pre-treatment.

The purpose of this research was to process a mixture of paper waste and garden waste based on material flow analysis and to analyze its parameters based on water content, ash content, heating value, along with Thermogravimetry Analysis (TGA)/Derivative Thermogravimetry (DTG). The garden waste treatment process consists of shredding, drying with a rotary dryer, separator, and then shaving with a hammer mill. Paper waste only needs a shredder process. Then, the mixing process and pelletizing of paper waste as well as garden waste are carried out according to the variation (w/w) 100% paper (K100), 75% paper (K75), 50% paper (K50), 25% paper (K25), and 100% garden waste (K0). The water content ranged from 5.8 to 15.25%. From K0 to K100 samples, the ash content increased from 4.54 to 9.85%. A correlation of 0.9047 was found from samples K0 to K100. There was a correlation between increasing calorific value along with the mixture with paper waste. The caloric value in K0 to K100 increased from 13.11 to 19.03 MJ/kg. The TGA/DTG analysis reduced mass due to water evaporation, devolatilization, and carbonization processes.

The byproducts of anaerobic processes at municipal solid waste landfills are leachates and gas emissions. One of the landfills operating in the coastal area of Bali Island is the Suwung landfill. The objectives of this research is to identify the water quality index (WQI) and hydrogen sulfide (H 2 S) parameters, as well as the health complaints by the local community around the Suwung landfill. A total of 12 samples were taken from wells, and surface and coastal water bodies. The parameters measured in this study are TSS, DO, COD, BOD, and NO 3 -N. The comparison of the parameters were in accordance with PP No. 82 of 2001 for the second-class water quality standards. Each sample for the TSS and DO parameters meets only eight and five quality standards, respectively. Meanwhile the COD parameters are only met by one sample. For the BOD, all samples did not meet the second-class water quality standards. The WQI analysis showed that seven samples were slightly polluted and two samples were polluted moderately. The average WQI value per water quality is 4.12, which means that the water quality around the landfill is slightly polluted. The H 2 S parameters mention concentrations at four points do not meet air quality standards. Respondents felt uncomfortable with the odour caused by the H 2 S. The future implication of this study is to know the indications of public health conditions.

The coronavirus disease 2019 (COVID-19) shifts the characteristics of municipal waste. This paper aims to provide an overview of trends, impacts, and management during the COVID-19 pandemic globally. The increase in the generation of plastic waste and infectious waste is a new challenge during the COVID-19 pandemic. It was found that the emergence of plastic waste due to the consumption of food delivery becomes an issue in several countries. Despite the increment of plastic waste generation, the mass layoffs contributed to the decrease in the total urban waste generation in general. In addition to plastic waste, a surge of infectious waste from health facilities and household waste originating from residents infected with the SARS-COV-2 virus was observed. This infectious wastewater potentially leads to environmental disturbances to the rivers and oceans. To tackle global environmental concerns, sustainable waste management is required especially in the development of biodegradable personal protective equipment.