At the invitation of Professor Nan Zhongren, Professor Wang Shengli and Associate Professor Hu Yahu, Professor Liu Hui of China University of Geosciences (Wuhan) came to our university for an academic visit and exchange on May 16, 2021, and held a meeting in room 1615, Guanyun building, Lanzhou University, The academic reports entitled "iron cycle in key zones of the earth and its environmental significance" and "oil sunflower microbial co remediation of oil-contaminated soil and CO production technology and application of biodiesel" were carried out. The report was presided over by Professor Wang Shengli.

This report started from the meaning and function of the earth's key zones, the scientific research focused on the earth's key zones and the iron cycle in the earth's key zones. It pointed out that the interface of each medium unit is the key to the transformation of elements and materials, and emphasized that the redox cycle of iron directly regulates the formation and transformation of minerals in the sedimentary environment, the element cycle and the transformation of pollutants. Professor Liu Hui shared her team's research progress on "iron oxidation and its environmental effects in groundwater environment", "the impact of iron oxidation on the survival of microorganisms", "the impact of iron oxidation on biogeochemical processes" and "remediation of oil-contaminated soil". It was concluded that: (1) Oxygen exposure in dark groundwater environment can produce hydroxyl radicals, arsenic and tetracycline (one of the antibiotics) can be oxidized in the process of oxygen oxidation; (2) Iron oxidation has different killing effects on different geological function microorganisms, and iron oxidation kills a large number of iron-reducing bacteria MR-1; (3) In the presence of iron-reducing bacteria, the oxidation of Fe²⁺promoted the subsequent biological reduction of iron, and the bioavailability of Fe³⁺in the presence of bacteria increased. Benzene had no effect on the survival of iron-reducing bacteria MR-1. Benzene promoted the biological reduction of iron, and benzene promoted the secretion and electron transfer of electron shuttle FMN;（4) The new technology of oil sunflower and high efficient degradation bacteria for remediation of oil-contaminated soil was firstly formed and applied in engineering. The technology route of using oil sunflower seed oil produced by remediation of oil-contaminated soil as biodiesel raw material was proposed for the first time, and the co-production of oil-contaminated soil remediation and biodiesel was realized; A new material MnCO₃/ Na₂SiO₃granular catalyst was independently developed. Based on this new material, the equipment for continuous clean production of biodiesel by heterogeneous catalysis was designed and manufactured, and the pilot production was successfully carried out. In view of each related scientific problem, Professor Liu Hui gave a detailed explanation in terms of research background and significance, research ideas, main innovations and research contents.

After the report, Professor Liu Hui had a positive interaction with Professor Nan Zhongren, Professor Wang Shengli, Associate Professor Hu Yahu of Lanzhou University, Senior Engineer Xu Shenghui, Associate Professor Wang Yan of Lanzhou University of Technology, and the postgraduate students; After the meeting, in view of the remediation of nitrobenzene contaminated sites and oil-contaminated soil in arid areas, as well as the treatment technology of arsenic pollution in groundwater, the two sides had a positive exchange on further in-depth cooperation in scientific research projects and reached a preliminary intention.