This work demonstrated that Enteromorpha biochar with introduced iron (SFB900-3) could activate peroxymonosulfate (PMS) efficiently for NTP remediation. It removed 83.9%–95.1% of NTP in 60 min under a wide pH range from 3.15 to 8.95. Density functional theory (DFT) calculations revealed the synergistic relationship between internal Fe single atoms and introduced Fe compounds—Fe₃C. The adsorption capacity of SFB900-3 for persulfate improved from −0.953 eV to −4.214 eV, and the Bader charge analysis showed that Fe atoms as active sites (0.658 e) enhanced the adsorption capacity more than carbon (0.050 e). Moreover, the energy barrier for PMS dissociation reduced from 0.072 eV to −5.372 eV due to the longer length of O–O bond under the synergistic effect of Fe single atom and Fe₃C which increased from 1.467 Å to 3.890 Å. The quenching experiment confirmed that ¹O₂ was the main active substance in NTP degradation and its contribution rate was 88.2%, which was further verified by EPR detection. The effect factor experiments proved that the SFB900-3/PMS system had stable and efficient activity for NTP removal, which remained at 73.6% removal rate after three rounds of tests. This work provided novel guidance for constructing efficient and stable biochar-based materials for organic pollutant remediation. Graphical Abstract

Germanium (Ge) is a widely distributed but rare element on earth. Organic germanium is the most widely used form of germanium. Compared to the common metal (mercury, cadmium, lead, etc.), organic germanium is much less toxic to humans than others. Since its discovery in 1886, organic germanium and relative compounds have caused many medically related problems across the globe. In most cases, organic germanium exists in the natural environment in an oxidation state. The size of organic germanium and its compounds is extremely small in natural water, for which organic germanium can easily enter the environment through the flow of water. Because organic germanium owns unique chemical properties and is potentially ecotoxic, so there are have special environmental problems. Considering the fact that people does not know much about organic germanium, along with the lack of systematic research, this paper starts with a brief introduction of the chemical composition, distribution, and threat to human health of organic germanium. Then, the new and common technologies for the recovery and removal of germanium as referred to in various literatures introduced and with detail description of their performance, advantages, disadvantages, and applications. It is of great significance for people to understand organic germanium and its pollution control.