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Key Facts: Engineer Waste Treatment (폐기물처리기사) Exam

80 Questions / 120 Min

Written exam from 2026: 4 subjects, 20 questions each, CBT four-option multiple choice

HRD Korea / Q-Net 출제기준

40% / 60%

Passing requirement: 40-point subject floor (과락) and 60-point overall average

National Technical Qualifications Act Enforcement Decree

KRW 19,400 / KRW 22,600

Official fees for the written (필기) and practical (실기) examinations

HRD Korea official fee schedule

2-Year Exemption

Written pass validity window for practical exam registration

HRD Korea examination operation rules

Wastes Control Act Art. 34

Statutory mandate for Environmental Technical Manager (환경기술인) appointment

Ministry of Environment statutory regulations

80 MCQs

Questions in this independent English-language study bank

OpenExamPrep practice bank

Administered by HRD Korea (한국산업인력공단 / Q-Net) under the Ministry of Environment, the Engineer Waste Treatment (폐기물처리기사) written examination is 80 four-option multiple-choice questions across 4 subjects in 120 minutes, with at least 40 points required in every subject and 60 points overall. Written fee KRW 19,400; practical fee KRW 22,600. This 80-question bank is an independent English-language MCQ study adaptation by OpenExamPrep — not an official translation or format simulation — built to the subject list that took effect on 1 January 2026.

Sample Engineer Waste Treatment (폐기물처리기사) Practice Questions

Try these sample questions to review concepts for the Engineer Waste Treatment (폐기물처리기사) exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 80+ question experience with AI tutoring.

1Under the Wastes Control Act (폐기물관리법) of South Korea, how are wastes fundamentally classified by source and hazard level?

A.Hazardous Waste and Non-hazardous Waste only, without administrative distinction between household and commercial origins

B.Municipal Solid Waste and Business Waste, where Business Waste is subdivided into Business General Waste, Designated Waste, and Construction Waste

C.Combustible Waste, Non-combustible Waste, and Recyclable Waste based solely on calorific value and physical recyclability

D.Municipal Waste, Industrial Waste, and Radioactive Waste under unified jurisdiction of the Ministry of Environment

Explanation: Under Article 2 of the South Korean Wastes Control Act (폐기물관리법), waste is legally bifurcated into Municipal Solid Waste (생활폐기물: wastes generated from domestic daily life) and Business Waste (사업장폐기물: wastes from business facilities with discharge facilities or generating 300 kg/day or more). Business Waste is further classified into Business General Waste (사업장일반폐기물), Designated/Hazardous Waste (지정폐기물), and Construction Waste (건설폐기물).

2A municipality with an active population of 400,000 residents generates 440 metric tons of municipal solid waste per day. What is the daily per capita waste generation rate (발생원단위)?

A.0.91 kg/person·day

B.1.10 kg/person·day

C.1.25 kg/person·day

D.1.45 kg/person·day

Explanation: The unit waste generation rate (발생원단위) is calculated as Total Daily Waste Generation (kg/day) divided by Population (persons). Here, 440 metric tons/day = 440,000 kg/day. Thus, Unit Generation Rate = 440,000 kg/day ÷ 400,000 persons = 1.10 kg/person·day.

3In proximate analysis (삼성분 / 사성분 분석) of solid waste, what components constitute the total mass balance, and how is fixed carbon (고정탄소) determined?

A.Total mass = Moisture + Volatile Matter + Ash; Fixed Carbon is calculated as 100% - (Moisture + Volatile Matter + Ash)

B.Total mass = Carbon + Hydrogen + Oxygen + Nitrogen; Fixed Carbon is determined by gas chromatography

C.Total mass = Moisture + Combustibles; Fixed Carbon is directly measured by heating at 105°C for 24 hours

D.Total mass = Ash + Fixed Carbon; Volatile matter is determined by subtracting total organic carbon from COD

Explanation: Proximate analysis divides solid waste into four components: Moisture (수분, determined by drying at 105–110°C), Volatile Matter (휘발분, driven off by heating in an enclosed crucible at 950°C without oxygen), Ash (회분, the inorganic residue remaining after complete combustion at 600–800°C), and Fixed Carbon (고정탄소). Fixed Carbon is calculated by difference: Fixed Carbon (%) = 100% - [Moisture(%) + Volatile Matter(%) + Ash(%)].

4The ultimate elemental analysis of a combustible waste on an as-received wet basis yields: Carbon (C) = 45%, Hydrogen (H) = 6%, Oxygen (O) = 24%, Nitrogen (N) = 1%, Sulfur (S) = 1%, Ash = 8%, and Moisture (W) = 15%. Using Dulong's modified formula [LHV = 8100C + 34000(H - O/8) + 2500S - 600(9H + W) kcal/kg], what is the lower heating value (저위발열량, LHV)?

A.3,450 kcal/kg

B.3,865 kcal/kg

C.4,275 kcal/kg

D.4,685 kcal/kg

Explanation: Let us compute step by step using Dulong's formula: 1) Gross/higher heating value terms: 8100 * C = 8100 * 0.45 = 3,645 kcal/kg 34000 * (H - O/8) = 34000 * (0.06 - 0.24/8) = 34000 * (0.06 - 0.03) = 34000 * 0.03 = 1,020 kcal/kg 2500 * S = 2500 * 0.01 = 25 kcal/kg Total gross contribution = 3,645 + 1,020 + 25 = 4,690 kcal/kg 2) Latent heat of vaporization of water: Water vapor formed from combustion of hydrogen = 9 * H = 9 * 0.06 = 0.54 kg H2O/kg waste Inherent moisture W = 0.15 kg H2O/kg waste Total water = 9H + W = 0.54 + 0.15 = 0.69 kg H2O/kg waste Latent heat deduction = 600 * (9H + W) = 600 * 0.69 = 414 kcal/kg (using standard engineering formula with 600 kcal/kg latent heat) LHV = 4,690 - 414 = 4,276 kcal/kg (rounded to 4,275 kcal/kg).

5What is the thermodynamic distinction between Higher Heating Value (고위발열량, HHV) and Lower Heating Value (저위발열량, LHV) of solid waste?

A.HHV is measured under vacuum conditions, whereas LHV is measured at standard atmospheric pressure

B.HHV applies only to plastic and rubber wastes, whereas LHV applies to paper and biomass wastes

C.HHV reflects the sensible heat of flue gas, whereas LHV includes chemical energy lost through incomplete combustion of CO

D.HHV includes the latent heat of vaporization of water in the combustion products (liquid water at standard temperature), whereas LHV assumes water leaves in the vapor state without recovering latent heat

Explanation: Higher Heating Value (고위발열량, Gross Calorific Value) represents the heat released when combustion products are cooled back to the reference temperature (typically 20°C or 25°C) so that water vapor condenses into liquid, releasing its latent heat of vaporization (~600 kcal/kg or 2,500 kJ/kg H2O). Lower Heating Value (저위발열량, Net Calorific Value) subtracts this latent heat because flue gases in practical incinerators leave the stack above 150°C, meaning water remains as steam: LHV = HHV - 600(9H + W) kcal/kg.

6A waste collection truck transports 150 m³ of uncompacted municipal solid waste having an initial bulk density (겉보기밀도) of 180 kg/m³. After passing through a rotary compactor, the compacted waste has a bulk density of 720 kg/m³. What is the Compaction Ratio (압축비, r) and the Volume Reduction Ratio (용적감소율, %)?

A.Compaction Ratio = 5.0; Volume Reduction Ratio = 80%

B.Compaction Ratio = 4.0; Volume Reduction Ratio = 75%

C.Compaction Ratio = 3.0; Volume Reduction Ratio = 66.7%

D.Compaction Ratio = 0.25; Volume Reduction Ratio = 25%

Explanation: Total mass is conserved: M = V1 * ρ1 = 150 m³ * 180 kg/m³ = 27,000 kg. Compacted volume V2 = M / ρ2 = 27,000 kg / 720 kg/m³ = 37.5 m³. 1) Compaction Ratio (압축비, r) = Initial Volume (V1) / Compacted Volume (V2) = ρ2 / ρ1 = 720 / 180 = 4.0 (or 4:1). 2) Volume Reduction Ratio (용적감소율, R) = [(V1 - V2) / V1] * 100% = [(150 - 37.5) / 150] * 100% = (1 - 1/r) * 100% = (1 - 0.25) * 100% = 75%.

7A sample of compacted waste at a landfill has a bulk density (겉보기밀도, wet) of 900 kg/m³ and a true solids particle density (진밀도) of 1,800 kg/m³. Assuming a dry basis where moisture is accounted for or negligible in the solid structure, what is the porosity (공극률, n) of this waste mass?

A.25%

B.33.3%

C.50%

D.66.7%

Explanation: Porosity (공극률, n) is defined as the ratio of void volume to total volume: n = V_void / V_total = 1 - (V_solids / V_total) = 1 - (Bulk Density / True Particle Density). Here, n = 1 - (900 kg/m³ / 1,800 kg/m³) = 1 - 0.50 = 0.50, or 50%. In void ratio terms (공극비, e), e = n / (1 - n) = 0.5 / 0.5 = 1.0.

8In empirical formulas for calculating the heating value of solid fuels and waste, what fundamental assumption distinguishes the Steuer formula from the Dulong formula?

A.The Steuer formula assumes zero heat contribution from sulfur oxidation, whereas Dulong treats sulfur as the primary heat contributor

B.The Steuer formula calculates heating value exclusively from proximate analysis (moisture, volatile matter, ash), whereas Dulong requires only nitrogen and chlorine content

C.The Steuer formula uses units of BTU/lb, whereas Dulong is only applicable in MegaJoules per kilogram

D.The Steuer formula accounts for oxygen bound to both hydrogen and carbon (assuming carbon monoxide and water formation equilibria), whereas the Dulong formula assumes all oxygen binds exclusively with hydrogen as water (O/8)

Explanation: Dulong's formula assumes all fuel oxygen is bonded with hydrogen in the ratio of water (O/8), leaving [H - O/8] as 'net combustible hydrogen'. However, in oxygen-rich wastes, oxygen also binds with carbon. The Steuer formula [LHV = 8100(C - 3O/8) + 5700(3O/8) + 34500(H - O/16) + 2500S - 600(9H + W) kcal/kg, or variations] accounts for the partial binding of oxygen with carbon (3/8 O) and hydrogen (1/16 O), providing greater accuracy for biomass and cellulosic wastes with high oxygen content.

9The particle size distribution of shredded municipal solid waste is frequently modeled using the Rosin-Rammler distribution equation: R = 100 * exp[-(x / x0)^n]. What does the parameter 'R' represent in this formulation?

A.Cumulative mass percentage of particles retained on a sieve of aperture size x

B.Total energy consumed during the shredding process in kilowatt-hours per ton

C.Void ratio of the compacted waste particle assemblage

D.Percentage of organic volatile matter volatilized during thermal treatment

Explanation: In the Rosin-Rammler particle size distribution model widely applied to crushed refuse and minerals, R represents the cumulative mass percentage of material retained on a screen of mesh size x [R = 100 * exp(-(x / x0)^n)], where x0 is the characteristic particle size (the aperture size at which R = 100 * e^(-1) ≈ 36.8%, meaning 63.2% passes through), and n is the uniformity coefficient (distribution parameter). Korean terminology: 상사누적잔류율, %.

10Which of the following field survey techniques is the most direct and accurate method for determining the daily waste generation rate of a specific urban residential collection route?

A.Questionnaire surveys asking residents to self-estimate weekly trash mass in kilograms

B.Load-Count & Weigh-Scale Analysis (적재차량 계량법): recording truck tare and gross weights at the weighbridge over a continuous sampling period

C.Measuring sewer wastewater COD concentrations and back-calculating solid food waste mass

D.Materials-Balance Analysis (물질수지법) applied to consumer retail product sales statistics

Explanation: Direct weighbridge measurement of collection vehicles (적재차량 계량법 / 차중계량법) across entire collection zones over defined time periods (accounting for tare weight and full truck gross weight) provides the most reliable and direct field empirical data for municipal waste generation rates. Materials balance analysis and questionnaires involve significant indirect assumptions and behavioral reporting errors.

About the Engineer Waste Treatment (폐기물처리기사) Exam

The Engineer Waste Treatment (폐기물처리기사) is South Korea's premier national technical qualification administered by HRD Korea under the Ministry of Environment. The certification validates advanced engineering competency in waste management, physical and chemical separation, mechanical processing, aerobic composting, anaerobic digestion, sanitary landfill construction, thermal incineration engineering, waste heat boiler operation, hazardous waste leaching analysis under Korean Standard Test Methods, and regulatory compliance under the Wastes Control Act (폐기물관리법) and resource circulation legislation. This module is an independent English-language MCQ study adaptation by OpenExamPrep, preserving authentic Korean technical terminology alongside comprehensive English pedagogical explanations. Independent practice by OpenExamPrep.

Exam sponsor: Ministry of Environment (환경부) / HRD Korea (한국산업인력공단). The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Assessment

Written examination (필기): Subject 1: Introduction to Waste Management (폐기물개론, 20 items); Subject 2: Waste Recycling and Resource Recovery Technology (폐기물 재활용 및 자원화 기술, 20 items); Subject 3: Waste Disposal Technology (폐기물 처분 기술, 20 items); Subject 4: Waste Standard Test Methods (폐기물공정 시험기준, 20 items), sat together over 120 minutes at 30 minutes per subject. Candidates must score at least 40 points in every subject to avoid subject failure (과락) and at least 60 points overall. Practical examination (실기): 폐기물처리 실무, a written-answer paper of about 3 hours marked out of 100, with 60 points required to pass.

Time Limit

120 minutes (2 hours) for the written examination; about 3 hours for the written-answer practical

Passing Score

At least 40 points in each subject (과락 40점 미만 방지) and an overall arithmetic average of at least 60 points out of 100 (전과목 평균 60점 이상)

Exam / Certification Fees

KRW 19,400 (Written Examination / 필기시험); KRW 22,600 (Practical Examination / 실기시험)

Exam sponsor website

Fees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.

Official sources

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

25%

Subject 1: Introduction to Waste Management (폐기물개론)

Statutory waste classification under the Wastes Control Act (생활폐기물 / 사업장폐기물 / 지정폐기물 / 건설폐기물) and the thresholds that make a site a business-waste generator, generation rates and unit generation, proximate and ultimate analysis, higher and lower heating value and the Dulong relationship, compaction ratio and volume reduction, bulk density and porosity, moisture and dry-basis conversion, particle size distribution, biodegradability and lignin, chlorine-bearing plastics, and the designated-waste thresholds for waste acid, waste alkali, waste oil and sludge.

25%

Subject 2: Waste Recycling and Resource Recovery Technology (폐기물 재활용 및 자원화 기술)

Comminution laws (Rittinger, Kick, Bond) and shredding equipment, trommel screening and critical speed, air classification, eddy-current and float-sink separation, aerobic composting parameters and C/N balancing, pathogen destruction standards, anaerobic digestion stages and the Buswell equation, solid recovered fuel quality standards and certification, waste-heat boiler steam generation, gasification and pyrolysis, the negative recycling regulation system, Extended Producer Responsibility, and construction waste and recycled aggregates.

25%

Subject 3: Waste Disposal Technology (폐기물 처분 기술)

Sludge dewatering and conditioning, solidification and stabilisation, landfill leachate estimation by the rational method, the three Ts of combustion, theoretical air and flue gas stoichiometry, excess air ratio from flue gas oxygen, adiabatic flame temperature, stoker, fluidised bed and rotary kiln furnaces, de novo dioxin synthesis and quench control, SNCR and SCR, semi-dry acid gas absorption, activated carbon injection, ash melting and vitrification, fly ash as designated waste, and landfill post-closure management.

25%

Subject 4: Waste Standard Test Methods (폐기물공정 시험기준)

The leaching test and its statutory thresholds, moisture determination and constant weight, ignition loss, flame and cold-vapour atomic absorption, hexavalent chromium by diphenylcarbazide, ICP-OES, PCBs by GC-ECD, dioxins by HRGC/HRMS, cyanide distillation pretreatment, headspace and purge-and-trap for volatile organics, BOD with nitrification inhibition, dichromate versus permanganate COD, total nitrogen by persulfate digestion, total phosphorus by ascorbic acid reduction, suspended solids, n-hexane extractable material, and matrix spike recovery.

Preparing for the Engineer Waste Treatment (폐기물처리기사) Exam

What You Need to Know

Passing score: At least 40 points in each subject (과락 40점 미만 방지) and an overall arithmetic average of at least 60 points out of 100 (전과목 평균 60점 이상)
Assessment: Written examination (필기): Subject 1: Introduction to Waste Management (폐기물개론, 20 items); Subject 2: Waste Recycling and Resource Recovery Technology (폐기물 재활용 및 자원화 기술, 20 items); Subject 3: Waste Disposal Technology (폐기물 처분 기술, 20 items); Subject 4: Waste Standard Test Methods (폐기물공정 시험기준, 20 items), sat together over 120 minutes at 30 minutes per subject. Candidates must score at least 40 points in every subject to avoid subject failure (과락) and at least 60 points overall. Practical examination (실기): 폐기물처리 실무, a written-answer paper of about 3 hours marked out of 100, with 60 points required to pass.
Time limit: 120 minutes (2 hours) for the written examination; about 3 hours for the written-answer practical
Exam / certification fees: KRW 19,400 (Written Examination / 필기시험); KRW 22,600 (Practical Examination / 실기시험) Official sources

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Engineer Waste Treatment (폐기물처리기사): Suggested Study Strategy

1Master Combustion Air & Flue Gas Stoichiometry: Commit to memory theoretical oxygen Oo, theoretical air Ao = Oo / 0.21, air ratio m = A / Ao, and theoretical dry/wet flue gas volumes (Go, Gw) from ultimate elemental analysis (C, H, O, N, S). Practice solving for m using actual flue gas O2 percentage: m = 21 / (21 - O2%).

2Use Dulong's relationship for heating value, but do not memorise competing empirical coefficient sets: LHV = 8100C + 34000(H − O/8) + 2500S − 600(9H + W) kcal/kg. Understand why 600(9H + W) is subtracted — it is the latent heat of the water formed from fuel hydrogen plus the inherent moisture — and why (H − O/8) is the net available hydrogen.

3Understand Waste Leaching Test (용출시험) Rules: Memorize the exact conditions specified in the Korean Standard Test Methods: solid-to-liquid extraction ratio of 1:10 (w/v), extraction water adjusted to pH 5.8 to 6.3 with hydrochloric acid, continuous shaking for 6 hours at 200 rpm with a 4 to 5 cm shaking stroke, and filtration through a 1.0 µm glass fiber filter.

4Master Composting C/N Balancing Calculations: Practice calculating the required mixing ratio of high-carbon bulk agents (e.g., sawdust, C/N ~ 400) and high-nitrogen waste sludge (C/N ~ 10–15) to achieve the optimal initial composting range of 25:1 to 35:1.

5Know the designated-waste thresholds in Enforcement Decree Table 1: waste acid at pH 2.0 or below, waste alkali at pH 12.5 or above, waste oil at 5% or more oil content, and sludge at under 95% moisture or 5% or more solids — together with the leaching limits of 3.0 mg/L lead and 0.3 mg/L cadmium.

6Familiarize Yourself with the Allbaro Electronic Manifest System (올바로시스템): Learn the statutory transmission deadlines under the Wastes Control Act: the waste generator must transmit the electronic manifest before handing waste to the transporter, the transporter must confirm within 2 days of delivery, and the disposal operator must register receipt within 2 days and completion of treatment within 30 days.

Frequently Asked Questions

What is the Engineer Waste Treatment (폐기물처리기사) qualification and who administers it?

It is an Engineer-grade national technical qualification under South Korea's National Technical Qualifications Act (국가기술자격법), administered by the Human Resources Development Service of Korea (한국산업인력공단 / Q-Net) under the Ministry of Environment (환경부). Holders plan, supervise and audit the collection, recycling, incineration and landfilling of municipal, business and designated wastes, and the qualification supports the statutory appointment of an Environmental Technical Manager (환경기술인) at a waste treatment facility.

What is the official examination format, time limit and passing standard?

Since 1 January 2026 the written examination has been 80 four-option multiple-choice questions across 4 subjects, 20 questions each, delivered by CBT in 120 minutes: (1) 폐기물개론, (2) 폐기물 재활용 및 자원화 기술, (3) 폐기물 처분 기술, and (4) 폐기물공정 시험기준. Candidates must score at least 40 points in every subject and at least 60 points overall. The practical examination is a written-answer paper (폐기물처리 실무) of about 3 hours, passed at 60 points out of 100.

What changed in the 2026 examination standard?

The written paper fell from five subjects and 100 questions to four subjects and 80 questions, and from 150 to 120 minutes. 폐기물처리기술 was reorganised into 폐기물 재활용 및 자원화 기술, 폐기물소각 및 열회수 into 폐기물 처분 기술, and the standalone 폐기물 관계 법규 subject was removed, with its statutory content distributed across the remaining papers.

What are the eligibility routes?

Graduates (or final-year students) of four-year programmes in environmental engineering or a related discipline; three-year junior college graduates with one year of relevant experience; two-year junior college graduates with two years; holders of the Industrial Engineer grade with one year; holders of a Craftsman qualification with three years; or four years of verified practical experience in the field. Confirm your own route with the Q-Net eligibility self-check.

What fees apply and how long does a written pass last?

The written examination fee is KRW 19,400 and the practical examination fee is KRW 22,600. A written pass exempts the candidate from the written paper for two years from the date the written result is announced, during which the practical examination may be taken in any round.

Is this OpenExamPrep practice bank an official test or translation?

No. The official examination is administered in Korean. This bank is an independent English-language MCQ study adaptation by OpenExamPrep — not an official translation, a format simulation, or a substitute for the written-answer practical examination.