Agricultural and Biosystems Engineers Licensure Examination (ABELE) · Philippines · Professional Regulatory Board of Agricultural and Biosystems Engineering, PRC
Original practice questions written to the published syllabus · not past papersHandling residues, manure and wastewater so that farms and plants do not pollute soil, water and air.
In the exams: NCEES PE Natural Resources & Environmental Systems and nutrient management; PRC ABE waste management; electives in the ICAR 6th Deans' Committee B.Tech
Agricultural and Biosystems Engineers Licensure Examination (PRC ABE)
Waste management within the structures and environment paper: composting process and C:N, biogas and lagoon concepts, BOD and COD definitions, wastewater treatment stages, livestock waste handling, environmental impact assessment and the relevant Philippine laws and standards (check the current PAES and DENR texts).
How our questions for Agricultural and Biosystems Engineers Licensure Examination spread across the units of Agricultural Waste Management & Environmental Engineering. Difficulty: 31 easy, 33 medium, 3 hard.
| Composting | 11 | |
| Crop-residue management | 10 | |
| Environmental impact assessment | 10 | |
| Basics of wastewater treatment | 9 | |
| Manure handling systems | 9 | |
| Wastewater characteristics: BOD and COD | 6 | |
| Anaerobic lagoons | 5 | |
| Nutrient management plans | 4 | |
| Air quality and odour | 3 |
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
A food plant sends 750 kg of BOD5 per day to treatment. Taking the domestic contribution as 60 g BOD5 per person per day (this figure differs between countries and texts), its population equivalent is:
D. 12,500 persons
PE = 750,000 g/d ÷ 60 g/person/d = 12,500 persons. 1,250 and 125,000 are factor-of-ten slips in converting kg to g; 45,000 multiplies 750 by 60 instead of dividing.
Anaerobic lagoons are built relatively deep compared with facultative ponds mainly because depth:
D. Reduces surface area, lowering odour release and heat loss
For a given volume, a deeper lagoon has less surface, so less odour escapes and less heat is lost, which helps the anaerobic bacteria. Algal oxygen and wind mixing are features of facultative ponds; liner rules depend on soil and local standards, not depth.
During the thermophilic phase of a well-managed compost pile, core temperatures are commonly in the range of:
B. 45–70 °C
Thermophilic microbes dominate from about 45 °C, and well-run piles commonly run 55–65 °C, which inactivates pathogens and weed seeds. Above roughly 70 °C microbial activity itself declines; 15–40 °C is mesophilic.
A compost mix of poultry manure and little bedding has a starting C:N of 10:1. The most likely problem is:
A. Loss of nitrogen as ammonia and strong odour
With too little carbon relative to nitrogen, microbes cannot use all the nitrogen, which is lost as ammonia, causing odour and lower fertiliser value. Slow decomposition from nitrogen shortage is the problem of high-C:N mixes such as straw alone.
The earthworm species most widely used in vermicomposting worldwide is:
C. Eisenia fetida, an epigeic surface-dwelling worm
Epigeic worms live in surface litter and eat organic matter, which suits vermicompost beds; Eisenia fetida (and in the tropics Eudrilus eugeniae) are the standard species. Anecic and endogeic worms burrow in mineral soil and do poorly in beds.
A compost feedstock has 60% moisture on a wet basis. Its moisture on a dry basis is:
A. 150%
Per 100 kg wet: 60 kg water, 40 kg dry. Dry-basis moisture = 60/40 = 150%. 40% is the dry-matter fraction; 60% repeats the wet basis; 67% is 40/60.
The '4R' framework of nutrient stewardship refers to the right:
C. Source, rate, time and place
4R is right source, right rate, right time and right place, the organising idea of nutrient management plans.
In the Leopold matrix, each interaction between a project action and an environmental component is scored for:
A. Magnitude and importance, each on a 1–10 scale
The Leopold matrix (developed for the US Geological Survey) crosses project actions with environmental characteristics and scores each interaction for magnitude and importance on scales of 1 to 10.
To show that manure spreading leads to nitrate leaching, then to well contamination, then to health effects in a village, the most suitable EIA identification method is:
B. A network or cause-effect diagram
Networks trace chains of primary, secondary and tertiary impacts. Checklists only list factors; a single map shows location but not cause and effect.
An engineer preparing an EIA for a new distillery in one country uses the project category thresholds from another country's rules. This is wrong because:
B. Categories, thresholds and procedures are set nationally and are revised
Which projects need EIA, the size thresholds, categories, timelines and hearing rules are national, and they are revised; the current official text of the country concerned must be used.
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