The Singapore Green Plan 2030 was released by the Singapore government to set targets for sustainability by 2030. The adoption of novel technologies, processes and substances creates new jobs, and such developments bring about new challenges and risks for both employers and workers. Beyond emerging hazards, traditional hazards still remain, but they may take on new forms through new work processes. This review aims to provide an overview of the potential occupational health issues we may encounter or anticipate in these key sectors: solar energy, waste management and recycling, green buildings, electric vehicles and battery recycling, and sustainable fuels. While existing Occupational Safety and Health regulations in Singapore serve as a foundation, there may be gaps in addressing the specific hazards and risks associated with green jobs. In this review, we propose and outline possible approaches to the protection of worker safety and health.
Singapore ; Humans ; Occupational Health ; Recycling ; Waste Management ; Solar Energy ; Occupational Exposure

The regulation of rhizosphere bacterial community structure and metabolism by plants in municipal solid waste landfills is a key to enhancing the biodegradation of chlorobenzene (CB). In this study, we employed biodiversity and metabolomics methods to systematically analyze the mechanisms of different plant species in regulating the rhizosphere bacterial community structure and metabolic features and then improved the methane (CH₄) oxidation and CB degradation capacity. The results showed that the rhizosphere soil of Rumex acetosa exhibited the highest CH₄ oxidation and CB degradation capacity of 0.08 g/(kg·h) and 1.72×10^-6 g/(L·h), respectively, followed by the rhizosphere soil of Amaranthus spinosus L., with the rhizosphere soil of Broussonetia papyrifera showing the weakest activity. Rumex acetosa promoted the colonization of Methylocaldum in the rhizosphere, and the small-molecule organic amine, such as triethylamine and N-methyl-aniline, secreted from the roots of this plant enhanced the tricarboxylic acid cycle and nicotinamide metabolism, thereby increasing microbial activity and improving CH₄ and CB degradation efficiency. Conversely, cinnamic acid and its derivatives secreted by Broussonetia papyrifera acted as autotoxins, inhibiting microbial activity and exacerbating the negative effects of salt stress on key microbes such as methanotrophs. This study probed into the mechanisms of typical plants growing in landfill cover soil in regulating bacterial ecological functions, offering theoretical support and practical guidance for the plant-microbe joint control of landfill gas pollution.
Biodegradation, Environmental ; Rhizosphere ; Soil Microbiology ; Waste Disposal Facilities ; Chlorobenzenes/metabolism* ; Bacteria/metabolism* ; Soil Pollutants/metabolism* ; Methane/metabolism* ; Plant Roots/microbiology* ; Amaranthus/microbiology* ; Soil

Polyethylene terephthalate (PET) fibers are characterized by exceptional mechanical strength, and textiles blended with cotton fibers combine both comfort and durability, showcasing widespread use in daily applications. However, improper disposal of discarded polyester-cotton textiles has resulted in severe environmental pollution, necessitating urgent and effective mitigation strategies. Enzymatic recycling of textiles offers superior environmental benefits and holds greater potential for industrial applications than alternative recycling methods. This study aims to explore a large-scale solution for the treatment of waste textiles, particularly addressing the challenge of resource recovery from polyester-cotton blended fabrics. An innovative enzymatic depolymerization process has been developed to achieve the recovery of high-purity terephthalic acid monomers. Experiments were conducted on three different textile blends with polyester-to-cotton ratios of 65/35, 70/30, and 80/20, and the influences of different colors on the process were investigated. Initially, the textiles were pretreated through mechanical grinding, which was followed by depolymerization of cotton fibers with commercial cellulase. The crystallinity of PET in the textiles was reduced through a rapid heating and cooling process. Subsequently, the PET was depolymerized by the engineered PET hydrolase. The results demonstrated that after decolorization and separation of terephthalic acid (TPA) from the reaction system, the monomer recovery rates for the three textile blends (65/35, 70/30, and 80/20) reached 90%, 91%, and 92%, respectively. Characterization analysis by nuclear magnetic resonance (NMR) confirmed that the purity of the recovered TPA was greater than 99%. In conclusion, the fully enzymatic recycling process developed in this study shows considerable promise for large-scale industrial applications and is anticipated to significantly advance the adoption and development of enzymatic recycling technologies for PET in industrial processes.
Phthalic Acids/chemistry* ; Polyesters/chemistry* ; Textiles ; Cotton Fiber ; Polyethylene Terephthalates/chemistry* ; Cellulase/chemistry* ; Recycling/methods* ; Polymerization

The rapid development of modern industries is accompanied with the aggravating water heavy metal pollution, which poses a potential threat to the aquatic environment and the health of local populations. As an efficient and economical adsorbent, biochar demonstrates the adsorption capacity for heavy metal ions and its adsorption capacity is significantly enhanced after modification. Therefore, biochar can effectively mitigate environmental pollution. By reviewing the existing studies, we summarize the modification methods of biochar, compare the advantages and disadvantages of physical, biological, and chemical modification methods, analyze the effects of modification on the adsorption capacity of biochar for heavy metal ions, and expound the modification mechanism of biochar. On this basis, this article puts forward the future research directions of the application of biochar in treating coexisting pollutants, aiming to provide a reference for the application of biochar in the purification of heavy metal-containing wastewater.
Charcoal/chemistry* ; Metals, Heavy ; Adsorption ; Wastewater/chemistry* ; Water Pollutants, Chemical/chemistry* ; Water Purification/methods* ; Heavy Ions ; Waste Disposal, Fluid/methods*

Anaerobic granular sludge (AnGS), a self-immobilized aggregate containing various functional microorganisms, is considered as a promising green process for wastewater treatment. AnGS has the advantages of high volume loading rate, simple process and low excess sludge generation, thus shows great technological and economical potentials. This review systematically summarizes the recent advances of the microbial community structure and function of anaerobic granular sludge, and discusses the factors affecting the formation and stability of anaerobic granular sludge from the perspective of microbiology. Moreover, future research directions of AnGS are prospected. This review is expected to facilitate the research and engineering application of AnGS.
Sewage/chemistry* ; Waste Disposal, Fluid ; Anaerobiosis ; Microbiota ; Water Purification ; Bioreactors/microbiology*

Water eutrophication poses great threats to protection of water environment. Microbial remediation of water eutrophication has shown high efficiency, low consumption and no secondary pollution, thus becoming an important approach for ecological remediation. In recent years, researches on denitrifying phosphate accumulating organisms and their application in wastewater treatment processes have received increasing attention. Different from the traditional nitrogen and phosphorus removal process conducted by denitrifying bacteria and phosphate accumulating organisms, the denitrifying phosphate accumulating organisms can simultaneously remove nitrogen and phosphorus under alternated anaerobic and anoxic/aerobic conditions. It is worth noting that microorganisms capable of simultaneously removing nitrogen and phosphorus absolutely under aerobic conditions have been reported in recent years, but the mechanisms remain unclear. This review summarizes the species and characteristics of denitrifying phosphate accumulating organisms and the microorganisms capable of performing simultaneous nitrification-denitrification and phosphorous removal. Moreover, this review analyzes the relationship between nitrogen removal and phosphorus removal and the underlying mechanisms, discusses the challenges of denitrifying phosphorus removal, and prospects future research directions, with the aim to facilitate process improvement of denitrifying phosphate accumulating organisms.
Phosphorus ; Phosphates ; Wastewater ; Denitrification ; Waste Disposal, Fluid ; Nitrogen ; Bioreactors/microbiology* ; Nitrification ; Sewage

The wide use of ZnO and CuO nanoparticles in research, medicine, industry, and other fields has raised concerns about their biosafety. It is therefore unavoidable to be discharged into the sewage treatment system. Due to the unique physical and chemical properties of ZnO NPs and CuO NPs, it may be toxic to the members of the microbial community and their growth and metabolism, which in turn affects the stable operation of sewage nitrogen removal. This study summarizes the toxicity mechanism of two typical metal oxide nanoparticles (ZnO NPs and CuO NPs) to nitrogen removal microorganisms in sewage treatment systems. Furthermore, the factors affecting the cytotoxicity of metal oxide nanoparticles (MONPs) are summarized. This review aims to provide a theoretical basis and support for the future mitigating and emergent treatment of the adverse effects of nanoparticles on sewage treatment systems.
Wastewater/toxicity* ; Sewage/chemistry* ; Zinc Oxide/chemistry* ; Waste Disposal, Fluid ; Nanoparticles/chemistry* ; Metal Nanoparticles/chemistry* ; Nitrogen/metabolism* ; Water Purification

At present, the negative impact caused by white pollution has spread to all aspects of human society economy, ecosystem, and health, which causes severe challenges for developing the circular bioeconomy. As the largest plastic production and consumption country in the world, China has shouldered an important responsibility in plastic pollution control. In this context, this paper analyzed the relevant strategies of plastic degradation and recycling in the United States, Europe, Japan and China, measured the literature and patents in this field, analyzed the status quo of technology from the perspective of research and development trends, major countries, major institutions, and discussed the opportunities and challenges faced by the development of plastic degradation and recycling in China. Finally, we put forward future development suggestions which include the integration of policy system, technology path, industry development and public cognition.
Humans ; Plastics ; Ecosystem ; Environmental Pollution ; Recycling ; Policy

Objectives: Since the effectiveness of the Zero Open Defecation (ZOD) program as a scaling-up approach in lowering the rates of soil-transmitted helminth (STH) infections has not yet been locally explored, this study aimed to (1) describe the association between environmental determinants and STH cumulative prevalence, and (2) to predict the 2020 STH cumulative prevalence. Methods: A generalized linear regression (GLR) model was used to determine the association of 2014–2015 environmental determinants and observed 2015 STH cumulative prevalence, while a geographically weighted regression (GWR) model was used to produce predicted 2020 STH cumulative prevalence. Results: ArcGIS’ GLR tool with R2 of 63% found that statistically significant environmental determinants include distance near to water bodies, forest land use, access to sanitary toilet, level one water source, and ZOD status, while the ArcGIS’ GWR tool found that barangays, Cabangcalan, Matalangtalang, Talabaan, and Talib in Aroroy hypothetically met the national target below 30% for 2020 STH cumulative prevalence. Conclusion This study showed that barangays with a moderately low percentage of area with freshwater bodies, a moderately high percentage of households with sanitary toilet and level one water source, and a 100% status of ZOD have lower rates of STH cumulative prevalence in preschool-aged children in the selected municipalities in Masbate.
Mass Drug Administration ; Hygiene ; Sanitation ; Geographic Information Systems

Aims: The primary aim of this study was to utilize abundant palm oil mill effluent (POME) waste and turn it into a value-added product of biomass fuel with high calorific energy value (CEV) via fermentation and drying process, then simultaneously reduce abundant liquid waste. Methodology and results: POME is available abundantly in Malaysia and only a small portion of it is utilized to produce other value-added products. In this study, fermentation of POME in the presence of bacteria (Lysinibacillus sp.) and fungus (Aspergillus flavus) separately at 37 °C, 180 rpm for 5 days, followed by overnight oven-drying at 85 °C was conducted. Four fermentation medium conditions were performed, viz.: (1) autoclaved POME, (2) autoclaved POME with the addition of Lysinibacillus sp., (3) autoclaved POME with the addition of A. flavus and (4) POME as it is (non-sterile). Conclusion, significance and impact of study Among all conditions, fermentation utilizing autoclaved POME in the presence of A. flavus evinced the highest CEV of 25.18 MJ/kg. The fermentation in the presence of Lysinibacillus sp. strain revealed high COD and BOD removal efficiency of 59.20% and 320.44 mg/L as well as the highest reduction of oils and grease among other groups with the value of 15.84%. Future research directions are proposed for the elucidation of co-fermentation in the presence of both Lysinibacillus sp. and A. flavus.
Palm Oil ; Biomass ; Biofuels ; Waste Disposal, Fluid