Antibiotics, widely used pharmaceuticals, enter wastewater treatment systems and ultimately the aquatic environment through the discharge of wastewater from residential areas, hospitals, breeding farms, and pharmaceutical factories, posing potential ecological and health risks. Due to the misuse and discharge of antibiotics, the spread of antibiotic resistance genes (ARGs) in water bodies and significant changes in microbial community structure have direct toxic effects on aquatic ecosystems and human health. This paper summarizes the occurrence of antibiotics in wastewater treatment systems and their ecological and health risks, focusing on the impact of antibiotics on aquatic microorganisms, aquatic plants and animals, and human health. It points out that existing wastewater treatment processes have poor removal capabilities for antibiotics and even become an important pathway for the spread of some antibiotics. In terms of detection technology, the article discusses the application of immunoassays, instrumental analysis, and emerging sensor technologies in detecting antibiotics in sewage, each with its advantages and limitations. Future efforts should combine multiple technologies to improve detection accuracy. Regarding the removal methods of antibiotics, the paper categorizes physical, chemical, and biodegradation methods, introducing various advanced technologies including membrane separation, adsorption, electrochemical oxidation, photocatalytic oxidation, and membrane bioreactors. Although these methods have shown good removal effects in the laboratory, there are still many limitations in large-scale practical applications. This paper innovatively takes urban wastewater treatment systems as the entry point, systematically integrating the sources of antibiotics, environmental risks, detection technologies, and treatment methods, providing targeted and practical theoretical support and technical guidance, especially in the removal of antibiotics in wastewater treatment, on a scientific basis. Future efforts should strengthen the control of antibiotic sources, improve the efficiency of wastewater treatment, optimize detection technologies, and promote the formulation and implementation of relevant laws and standards to more effectively manage and control antibiotic pollution in the aquatic environment.

In recent years, China has been vigorously carrying out the planning and implementation of Sponge City. Since the implementation of Sponge City projects involves substantial materials and energy consumption, it is significant to account corresponding carbon emissions and sinks. The existed studies about carbon emission of stormwater management measures, however, are not able to take the whole life cycle and different facilities into consideration. Therefore, this study develops a comprehensive accounting model based on Intergovernmental Panel on Climate Change (IPCC) guidelines and life cycle assessment (LCA) method to predict carbon emissions and carbon sinks of Sponge City projects more comprehensively and accurately. The model is applied to an actual residential community in Shanghai as a case study. Results show that the total indirect carbon emission is estimated to be 774,277 kg CO₂ eq during a 30-year lifespan, among which carbon emissions from operation and maintenance phases are 2570 kg CO₂ eq/year and 7309 kg CO₂ eq/year, respectively, both directly proportional to the service life of the facilities. Three kinds of achievable carbon sinks are carbon sequestration in green space (5450 kg CO₂ eq/year), carbon sink from rainwater utilization (15,379 kg CO₂ eq/year) and carbon sink from runoff pollutant removal (19,552 kg CO₂ eq/year). Carbon neutrality is expected to be reached after approximately 19 years. The established carbon emission accounting model can contribute to better planning and construction of Sponge City in China and enhance further energy conservation and carbon emission reduction.

Cement manufacturing and the treatment of sludge are considered both energy-intensive industries and major greenhouse gas (GHG) emitters. However, there are still few studies on comprehensive carbon footprint analysis for adding municipal sludge in the cement production. In this study, the lime-dried sludge blended with calcium oxide at the mass mixing ratio of 10% was utilized as raw material for the preparation of Portland cement. The chemical and physical properties of sludge were analyzed. A set of carbon footprint calculation methods of lime-drying treatment of sludge and reuse in cement kilns was then established to explore the feasibility of coprocessing lime-dried sludge in cement kilns. The results showed lime-dried sludge containing CaO, SiO₂, Al₂O₃, and Fe₂O₃ was ideal for cement production as raw material. However, the water content of lime-dried sludge should be strictly limited. The lime-drying process presented the biggest carbon emission (962.1 kg CO₂-eq/t sludge), accounting for 89.0% of total emissions. In the clinker-production phase, the lime-dried sludge as raw material substitute and energy source gained carbon credit of 578.8 and 214.2 kg CO₂-eq/t sludge, respectively. The sludge used for producing cement clinker could reduce carbon emissions by 38.5% to 51.7%. The addition ratio of lime and stacking time in the sludge lime-drying process could greatly affect the carbon footprint of coprocessing lime-dried sludge in cement kiln.

Thermal drying was used to reduce sludge moisture content before co-combustion in cement kilns. The characteristics of ammonia (NH₃) emission during thermal drying of lime sludge (LS) were investigated in a laboratory-scale tubular dry furnace under different temperature and time conditions. As the temperature increased, the NH₃ concentration increased in the temperature range 100–130°C, decreased in the temperature range 130–220°C and increased rapidly at >220°C. Emission of NH₃ also increased as the lime dosage increased and stabilized at lime dosages >5%. In the first 60 min of drying experiments, 55% of the NH₃ was released. NH₃ accounted for about 67–72% of the change in total nitrogen caused by the release of nitrogen-containing volatile compounds (VCs) from the sludge. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy revealed that the main forms of nitrogen in sludge were amides and amines. The addition of lime (CaO) could cause conversion of N–H, N–O or C–N containing compounds to NH₃ during the drying process.