The weapon was discovered during the day, before the Freshers' Ball took place, so it is thought that it was most likely to have been dropped by someone on the night of the 17th.
It is believed that a student discarded the blade after seeing that the QMU's security policy includes searching people and their bags at the door before allowing them to enter the venue.
Speaking to Guardian, Ally Hunter, President of the QMU, explained how he felt that the incident proved that security at the union serves to protect those who go there.
He said: "I think it just highlights how good our search policy is. During Freshers' Week we did confiscate a number of blades and handed them over to the police but there is no reason to step up security.
"The QM continues to be one of the safest places in Glasgow because of our security."
He went on to add that the knives confiscated mostly belonged to international students who were unaware of the law in Scotland.
He explained: "I think it's because some of the international students come from different cultures where carrying a knife isn't necessarily a crime. Some students are used to being able to carry a blade at home and are often surprised when told they have to be confiscated."
Security at the Glasgow University Union does not operate in the same way as at the QMU, as it does not require people to submit to a bag search before going in.
When asked whether the union would be revising how it conducts its security in the light of Thursday's events, GUU President Chris Birrell was keen to stress that the existing security arrangements had been working well for years.
He told Guardian: "We have not had any problems for as long as I have been around but I will definitely be taking this into consideration when reviewing GUU security."
A university spokesperson explained that, whilst it was not responsible for the security arrangements at either union, every effort was made to ensure the safety of students whilst on campus.
He said: "The safety and security of students is of paramount importance to the university and while the security at student union events are the responsibility of the QMU and GUU respectively, university security liases closely with the police to maintain a safe environment for students and staff in the wider campus."