His researches include wastewater-based epidemiology (WBE), antibiotic and antibiotic resistance genes, environmental microbiome engineering and biotechnology, anaerobic digestion and bioenergy from wastes/wastewater, biological wastewater treatment, etc. He has published over 320 peer-reviewed papers on the above topics, and has more than 35, 000 citations and an H index of 104 (Google Scholar). He serves as a senior editor of Microbiome and an editorial board member of ISME now. He had been Honorary Professor in School of Public Health of HKU from 2018 to 2020. He got First-Class Award in Natural Science (China Ministry of Education) in 2015, Second-Class Award State Natural Science Award (China State Council) in 2016, Outstanding Research Student Supervisor Award of HKU in 2017, Outstanding Research Award of HKU in 2020, HKU Innovator Award in 2021, Golden Metals of The International Exhibition of Inventions of Geneva in 2021 and 2022, Medal of Honor 2021 by HKSAR Government, HKIE Grand Award in 2023. He has been listed as “Highly Cited Researcher” by Clarivate in 2018 (Cross Field), 2019 (Environment and Ecology), both 2020 and 2021 (Environment and Ecology; Microbiology), and 2022 (Microbiology).