Environmental Engineering Doctoral Candidates Successfully Defend Their Dissertations at the Faculty of Environment

Environmental Engineering Doctoral Candidates Successfully Defend Their Dissertations at the Faculty of Environment

On the morning of August 9, 2025, the University of Science and Technology – the University of Danang (UD-DUT) held a doctoral dissertation defense at the specialized unit level for PhD candidate Phan Thi Kim Thuy with the thesis entitled: “Research on determining operational parameters of the nitrogen transformation process in wastewater treatment from seafood processing.”
The research, under the major of Environmental Engineering, was supervised by Assoc. Prof. Dr. Tran Van Quang (UD-DUT).

Speaking at the defense, Dr. Nguyen Cong Hanh – Deputy Head of the Training Department – emphasized:

“This is a meaningful event, marking the result of a serious and persistent process of study and research by the PhD candidate. This success affirms the training quality and scientific reputation of the University, as well as the dedicated companionship of the academic advisors and the Faculty’s staff.”

Dr. Hanh also expressed gratitude to the members of the evaluation committee and scientists from other institutions and enterprises who contributed valuable feedback, helping to improve postgraduate training quality.

At the defense, the committee reviewed the candidate’s academic background, study process, and research outcomes. The candidate had published seven scientific papers in reputable domestic and international journals, aligned with the dissertation’s topic. All members highly appreciated her research capacity and the results achieved.

Research objectives of the dissertation:

1. Assess the characteristics of wastewater from seafood processing (SP), current treatment technologies in use, and existing operational management issues in wastewater treatment plants (WWTPs).

2. Determine kinetic parameters of nitrification and denitrification processes for nitrogen removal; operational parameters of the A/O process for organic matter removal and nutrient transformation in SP wastewater.

3. Propose a set of parameters for operation, new design, upgrading, and retrofitting of biological treatment systems (A/O process) in SP WWTPs, suitable for each type of product and wastewater characteristics (C/N ratio).

Scientific significance:
The study adds important datasets on flow rate, discharge patterns, and characteristics of SP wastewater; clarifies the C/N ratio in wastewater from preliminary processing and surimi production; and provides detailed figures on organic components and nitrogen content. It also determines the kinetic parameters of the activated sludge process combined with nitrification–denitrification, as well as operational parameters of the A/O process. These results enrich the scientific database and serve as valuable references for treating low C/N ratio wastewater such as rubber or livestock wastewater.

Practical significance:
The results serve as important references for the design, upgrading, and retrofitting of SP WWTPs. The proposed operational parameters will help operators easily adjust and optimize systems, improving environmental management efficiency at factories, industrial clusters, and parks. The integrated, automated research model and experimental procedures can also be applied in undergraduate and postgraduate training, and serve as a basis for further nitrogen treatment research.

During the peer review, the committee praised the dissertation for its high scientific and practical value, appropriate research methodology, reliable results, and fulfillment of doctoral requirements. The candidate responded logically and convincingly, receiving 100% approval from the committee. Suggestions for revisions were provided to further improve the dissertation before presenting at a higher level.

In an emotional closing, PhD candidate Phan Thi Kim Thuy expressed her gratitude to the committee, academic advisors, colleagues at the Faculty of Environment, family, and friends for their unwavering support.

On the afternoon of the same day (August 9, 2025), UD-DUT also held a doctoral dissertation defense at the specialized unit level for PhD candidate Vo Diep Ngoc Khoi with the thesis entitled: “Research on treatment of sludge from urban wastewater treatment plants using co-composting technology with carrier materials under Vietnamese conditions.”
The research, under the major of Environmental Engineering, was supervised by Assoc. Prof. Dr. Tran Van Quang and Dr. Phan Nhu Thuc (Faculty of Environment, UD-DUT).

In his speech, Dr. Nguyen Cong Hanh – Deputy Head of the Training Department – reiterated the significance of the event, noting that it marked the culmination of a diligent and serious research process. He affirmed that such achievements underscore the quality of the University’s postgraduate programs and the dedicated guidance of faculty members. He also thanked the committee members and external experts for their valuable contributions.

The committee reviewed the candidate’s academic profile, study process, and research outcomes. The candidate had published six scientific papers in reputable domestic and international journals, aligned with the dissertation’s research content. The committee highly valued his research capacity and the results obtained.

Research objectives of the dissertation:

1. Approach the treatment of sludge from urban WWTPs with the orientation of reuse, recycling, and emission reduction, contributing to circular economy and green economy goals in Vietnam’s urban solid waste management strategy.

2. Determine parameters of the aerobic stabilization process for sludge mixed with carrier materials (co-composting) under Vietnamese conditions.

3. Assess the potential for reusing the final product of sludge stabilization as organic fertilizer.

Scientific significance:

• Identified Khaya senegalensis wood chips as a suitable carrier material, helping to balance moisture, increase porosity, and maintain C/N ratio during aerobic biodegradation.

• Clarified influencing factors in the composting process, including: stable temperature of 35–40°C; final moisture content of 25–30%; pH of 6–7.5; and sludge mass reduction efficiency of 85–89%.

• Based on the rotary-drum co-composting principle, the process produced a final product meeting Vietnam’s bio-organic fertilizer standards.

Practical significance:

• Provided scientific basis and operational parameters for models treating organic sludge with wood-based carriers, applicable to urban WWTPs.

• The final product can be used as organic fertilizer, helping to reduce waste pressure while supporting safe agricultural production.

In the peer review, the committee recognized the dissertation’s high scientific and application value, suitable methodology, reliable results, and fulfillment of doctoral requirements. The candidate responded convincingly, receiving 100% approval from the committee. Constructive feedback was provided for further improvement before presenting at a higher level.

In his closing remarks, PhD candidate Vo Diep Ngoc Khoi expressed heartfelt gratitude to the committee, academic advisors, colleagues at the Faculty of Environment, and especially his family, for their continuous encouragement and support in successfully defending the dissertation at the specialized unit level.