Cork Institute of Technology
Bachelor of Engineering in Building Services Engineering – Award
(EBSEN_7_Y3 )
Summer 2009
Environmental Services – Legacy exam
(Time: 3 Hours)
Answer FIVE questions.
All questions carry equal marks.
Examiners: Mr. W. Corr
Dr. M. Smyth
Mr. P. O’Sullivan
Q1. A meat plant processes 1500 cattle per day with loadings
BOD : 3.2 kg / beast
Wastewater : 1.6 m3 / beast
The proposed treatment plant consists of a roughing filter bio-tower followed by a
conventional aeration tank.
(i) Design the - bio-tower (5 marks)
- inter-stage settling tank (3 marks)
- aeration basin (5 marks)
- final settling tank (3 marks)
assuming upward flow 1.5 m / hr for both tanks; and MLSS 4500 mg / L,
F / M 0.20 kg BOD / day per kg MLSS for the aeration basin.
(ii) List all assumptions. (2 marks)
(iii) Will further treatment be necessary? (2 marks)
Q2. (a) Write concise notes on dioxins and furans under the following headings:
(i) Origin and chemical composition, particularly in respect of MSW and backyard
incineration. (5 marks)
(ii) Toxicity and health effects and the controversies surrounding this topic. (6 marks)
(iii) Generation and Removal within the incinerator stages. (6 marks)
(b) Define precisely the terms DRE, LD50, and ELV in relation to this topic. (3 marks)
