Despite its profound impact on athletic performance, the significance of heart rate recovery (HRR) has been insufficiently addressed in the filed of sports science, particularly in the context of weightlifting characterized by brief and intense exertions involving heavy weights. Serving as a valuable indicator of autonomic nervous system and cardiovascular function, HRR assumes a pivotal role in weightlifting. This comprehensive review aims to delineate the specific demands for HRR in weightlifting, shedding light on the often overlooked cardiovascular considerations within training regimes focused on strength and power. The investigation scrutinizes the repercussions of HRR on weightlifting performance, seeking to elucidate how inadequate recovery intervals may result in physiological and psychological consequences. These consequences encompass a distorted perception of effort, disruption of coordination, compromised posture due to irregular breathing, and an overall decline in lifting capacity. The review systematically presents compelling evidence pertaining to heart rate response and recovery patterns during weightlifting, underscoring the critical importance of well-structured rest periods. Furthermore, the review delves into a comprehensive discussion of factors influencing HRR in weightlifting, encompassing variables such as sex, age, cardiovascular function, hydration, nutrition, and psychological aspects. Finally, a key emphasis is placed on the integration of effective HRR techniques into the training regimens of weightlifters, thereby ensuring sustained and optimized performance outcomes.
본 연구는 알츠하이머(Alzheimer’s disease: AD) 형질전환 생쥐를 대상으로 저항성 운동 (resistance exercise: RE)이 해마의 베타 아밀로이드(β-amyloid: Aβ) 단백질 대사, 신경세포사멸 및 인지기능에 미치는 영향을 확인하는데 목적이 있다. AD 비 형질전환 생쥐(non-transgenic: non-tg, n=14) 와 형질전환 생쥐(transgenic: Tg, n=14)를 무선 배정하여 비 형질전환 생쥐 대조군 (non-tg-control: NTC, n=7), 비 형질전환 생쥐 저항성 운동군(non-tg-RE: NTRE, n=7), 형질전환 대조군(tg-control: TC, n=7) 및 형질전환 저항성 운동군(tg-RE: TRE, n=7)으로 구분하였다. RE는 특수 제작한 사다리 저항성 운동 기구를 사용하여 점진적으로 set 수를 증가시켜 총 8주간 실시하였다. 운동 후 인지기능 능력을 평 가하기 위한 수중미로검사와 Aβ 단백질 대사, 신경세포사멸 지표 및 SIRT1/PGC-1α 단백질 발현 수준 을 확인하였다. 수중미로검사 결과 거리와 시간 모두 TC 집단에서 유의하게 증가 되었지만 RE를 실시한 TRE 집단에서 거리와 시간이 감소 되어 인지능력이 개선된 것으로 확인되었다. 또한, TC 집단에서 증가 된 Aβ 단백질 발현은 RE를 통해 감소하는 것으로 나타났다. 신경세포사멸 관련 단백질인 Bcl-2/Bax ratio는 TC 집단에서 유의하게 감소되어 신경세포사멸이 증가 된 것으로 나타났지만 RE는 Bcl-2/Bax ratio을 증가시켜 신경세포사멸을 감소시킨 것으로 확인되었다. TC 집단에서 증가된 BACE1 및 ROCK1 과 감소된 ADAM10과 RARβ 단백질 발현은 RE를 통해 감소되거나 증가 된 것으로 나타났고, SIRT1/ PGC-1α 단백질 발현은 TC 집단에서 감소 되었지만 RE를 통해 증가 된 것으로 나타났다. 따라서 8주간 의 RE는 AD의 병리학적 특징인 Aβ 단백질 발현을 감소시키고 관련 생성 기전들을 조절하여 (SIRT1/PGC-1α 기전 활성, 아밀로이드 생성기전 억제, 비-아밀로이드 생성기전 활성) 신경세포사멸 억제시키고 결과적으로 인지기능을 개선 시킬 수 있는 효과적인 운동 방법이라고 생각된다.
Over the past two decades, the options for solid waste management have been changing from land disposal to recycling, waste-to-energy, and incineration due to growing attention for resource and energy recovery. In addition, the reduction of greenhouse gas (GHG) emission has become an issue of concern in the waste sector because such gases often released into the atmosphere during the waste management processes (e.g., biodegradation in landfills and combustion by incineration) can contribute to climate change. In this study, the emission and reduction rates of GHGs by the municipal solid waste (MSW) management options in D city have been studied for the years 1996-2016. The emissions and reduction rates were calculated according to the Intergovernmental Panel on Climate Change guidelines and the EU Prognos method, respectively. A dramatic decrease in the waste landfilled was observed between 1996 and 2004, after which its amount has been relatively constant. Waste recycling and incineration have been increased over the decades, leading to a peak in the GHG emissions from landfills of approximately 63,323 tCO2 eq/yr in 2005, while the lowest value of 35,962 tCO2 eq/ yr was observed in 2016. In 2016, the estimated emission rate of GHGs from incineration was 59,199 tCO2 eq/yr. The reduction rate by material recycling was the highest (-164,487 tCO2 eq/yr) in 2016, followed by the rates by heat recovery with incineration (-59,242 tCO2 eq/yr) and landfill gas recovery (-23,922 tCO2 eq/yr). Moreover, the cumulative GHG reduction rate between 1996 and 2016 was -3.46 MtCO2 eq, implying a very positive impact on future CO2 reduction achieved by waste recycling as well as heat recovery of incineration and landfill gas recovery. This study clearly demonstrates that improved MSW management systems are positive for GHGs reduction and energy savings. These results could help the waste management decision-makers supporting the MSW recycling and energy recovery policies as well as the climate change mitigation efforts at local government level.
This study examined the potentials for greenhouse gas reduction by material recovery and energy recovery from municipal solid waste between 2017 and 2026 in Daejeon Metropolitan City (DMC), which is trying to establish a material-cycle society by constructing a waste-to-energy town by 2018. The town consists of energy recovery facilities such as a mechanical treatment facility for fluff-type solid refuse fuel (SRF) with a power generation plant and anaerobic digestion of food waste for biogas recovery. Such recycling and waste-to-energy facilities will not only reduce GHGs, but will also substitute raw materials for energy consumption. The emissions and reduction rate of GHGs from MSW management options were calculated by the IPCC guideline and EU Prognos method. This study found that in DMC, the decrease of the amount of MSW landfilled and the increase of recycling and waste-to-energy flow reduced GHGs emissions from 167,332 tonCO2 eq/yr in 2017 to 123,123 tonCO2 eq/yr in 2026. Material recycling had the highest rate of GHG reduction (-228,561 tonCO2 eq/yr in 2026), followed by the solid refuse fuels (-29,146 tonCO2 eq/yr in 2026) and biogas treatment of food waste (-3,421 tonCO2 eq/yr in 2026). This study also shows that net GHG emission was found to be -30,505 tonCO2 eq in 2017 and -105,428 tonCO2 eq, indicating a great and positive impact on future CO2 emission. Improved MSW management with increased recycling and energy recovery of material waste streams can positively contribute to GHGs reduction and energy savings. The results of this study would help waste management decision-makers clarify the effectiveness of recycling MSW, and their corresponding energy recovery potentials, as well as to understand GHG reduction by the conversion.
Brominated flame retardants (BFRs) including PBDEs, TBBPA, and HBCD have been used in a variety of products such as automobiles, electronic products, building materials, and textiles. Because some of BFRs are known to be toxic, persistent, bioaccumulative in the environment, they have a great potential and possibility of human exposure and the environmental release through the use, treatment and disposal of products containing BFRs. Although there have been various efforts on laws and regulations of the restriction on the use of BFRs in many countries, only limited information regarding the levels, flow, treatment technology and regulations of products and wastes containing BFRs is available. In this study, the levels, current regulations and treatment guideline on products and wastes containing BFRs in electronics, automotives, construction materials, and textiles have been examined and summarized. Relative high levels of BFRs in TVs, construction materials and end-of-life vehicles were found, while textiles contained less amounts of BFRs. According to the study, more strengthened regulations are currently underway around the world. Thus, more limited use of BFRs such as deca-BDE in products and wastes is expected. Other chemicals such as TBBPA and HBCD are being evaluated for toxicity and risk assessment. Specific regulatory guideline of BFRs containing products after use (e.g. collection, separation, treatment) should be developed to prevent the widespread dispersion in the environment and human exposure of such chemicals as a result of improper disposal such as incineration and landfilling.
PBDEs, TBBPA 및 HBCD를 포함한 브롬계 난연제(BFRs)는 자동차, 전자 제품, 건축 자재 및 직물과 같은 다양한 제품에 사용되고 있다. 일부 브롬화 난연제는 환경적으로 독성, 지속성, 생체 축적성이 있는 것으로 알려져 있어 브롬화 난연제를 함유한 제품의 사용, 처리 및 처분을 통한 인체 노출 및 환경 배출 가능성이 있다. 많은 국가에서 브롬화 난연제 사용에 대한 규제에 관한 법률 및 규정이 다양하게 시행되고 있지만 BFR을 포함하는 제품 및 폐기물의 수준, 흐름, 처리 기술 및 규정에 관한 정보는 제한적으로 이용 가능한 실정이다. 본 연구의 연구 방법은 먼저 국내 브롬화 난연제 적용 현황 및 함유 제품 및 폐기물 내 브롬화 난연제 함량을 파악하였다. 또한 국내외 브롬화 난연제 함유 제품 및 폐기물에 대한 규제현황 및 처리현황을 파악하고 국내에서 적용 가능한 브롬화 난연제 함유 폐기물에 대한 관리기준 및 처리 방안울 제시하고자 하였다. 국내 브롬화 난연제 적용 현황, 함유 제품 및 폐기물 내 브롬화 난연제 함량 검토, 브롬화 난연제 함유 제품 및 폐기물의 규제현황 및 처리현황은 관련 연구보고서 및 논문검토 등 문헌조사 및 통계자료 조사를 통하여 실시하였다. 연구 결과, 1) 국내 유통되는 브롬화 난연제의 사용량은 전기・전자/자동차제품에 범용으로 적용되는 경우가 가장 많았으며(11,077톤), 전기전자, 건축자재, 운송수단의 순이었다. 2) 브롬화난연제 함유 폐기물 내 함량은 폐전기전자제품의 경우 TV가, 건축자재에서는 보온단열재 및 재활용 원료에서 높게 나타났다. 3) 국내외 브롬화 난연제 함유 제품 및 폐기물의 규제현황을 검토한 결과, 전 세계적으로 브롬화 난연제를 규제대상물질로 설정하여 제품 및 폐기물 내 함유 농도로 관리하고 있으나, 국내의 경우 폐기물에 대한 정의 및 관리기준이 수립되어 있지 않았다. 4) 국외 BFRs 함유 폐기물 처리 기술에 대한 조사 결과 재활용, 매립, 물리화학적 처리, 에너지회수 및 소각처리를 하고 있으며 EU 등 일부 국가에서는 브롬화 난연제 함유 물질의 매립을 금지하고 스톡홀름협약에서 제시한 최적가용조건으로 소각처리를 하고 있으나, 국내의 경우 아직까지 브롬화 난연제 함유 폐기물에 대한 처리지침이 수립되어 있지 않다. 본 연구는 브롬화 난연제 함유 폐기물 처리 및 적정 관리 방안 마련을 위한 자료로 활용이 가능하며, 항후 브롬화 난연제를 포함한 잔류성 유기 오염물 관리에 대한 정책 기초자료로 활용할 수 있다.
The most common types of refrigerants used in automobiles today usually include HCFCs and HFCs, which have the potential of ozone depletion or the greenhouse effect. Although environmentally friendly refrigerants are being developed, there is still a lack of safety and high-cost problems for new refrigerants. This study was conducted to determine the flow of refrigerants from automotive air conditioners and examine their potential problems and a proper management plan. The number of automobiles manufactured, the number of automobiles in use, and end-of-vehicle flow were examined through available statistics and reports. The material flow of refrigerants has been determined by the life cycle of automobiles and the unit requirements of the refrigerants used in automobiles. Based on the results, in 2014, there were approximately 1,017 tons of refrigerants introduced from the manufacturing stage of automobiles, and about 395 tons of refrigerants leaked from the use stage. After the use stage, only 13 tons of refrigerants were delivered to treatment facilities and 195 tons were emitted into the atmosphere during the dismantling process. As a result, in South Korea in 2014, a large amount of refrigerants (590 tons) was estimated to have been leaked into the atmosphere from automotive air conditioners during the use and dismantlement stage. Several preventive measures for refrigerants should be properly enforced by introducing economic incentives as well as a monitoring system with strengthened laws and policies.
수은은 온도계, 혈압계, 치과용 아말감, 전지, 형광등과 의약품 등 많이 사용되고 산업적으로도 전기 스위치, 촉매 등으로 중요하게 사용된다. 수은은 증기 흡입 시 폐렴을 유발하고 중추신경계와 신장에 영향을 줄 수 있을 정도로 매우 위험하여 수은과 수은 화합물의 사용이 금지되거나 제한을 받고 있으며, 대체물질과 대체 공정의 개발을 위한 노력이 행해지고 있다. 최근 연이은 병원, 학교 등의 혈압계, 온도계의 수은 누출사고와 형광등 생산시설인 (주)남영전구 광주공장의 해체 및 철거 중 수은 누출로 인한 근로자의 수은 중독 및 환경오염 사고와 비철금속업체의 수은 폐기물 처리문제가 대두되었다. 전국 병원 2,500개소 설문조사 결과, 143개 병원에서 혈압 및 체온계의 약 4천여개(수은량 : 약 140 kg)가 회수와 폐기가 필요한 것으로 조사되었다. 또한 미나마타 협약에서 요구되는 수은 수출・입, 공급원 파악, 임시보관 및 유통・보관, 회수, 처리 등 단계별 수은의 회수, 유통, 관리에 대한 체계 구축이 미흡하다. 수은폐기물은 미나마타협약에 의하여 ‘수은 구성 폐기물’, ‘수은 함유 폐기물’, ‘수은 오염 폐기물’로 나눠지고 본 연구에서는 ‘수은 함유 폐기물과 오염 폐기물’의 수입, 유통, 회수, 폐기 등 전과정 단계별 흐름 분석을 통하여 수은의 국내 흐름을 파악하고 관련 법 제도의 문제점을 분석하고자 함에 있다. 또한 수은 관련 유통량을 조사하고 폐기물의 처리 공정을 파악하여 대상 물질, 원료 사용량, 시스템 경계 설정, 데이터 수집 및 분석, 계산과 검증 등의 절차를 걸쳐 물질수지에 근거하여 ‘물질흐름도’를 작성하여 도출하였다. 물질흐름분석을 보다 쉽게 활용하고 적용할 수 있도록 ‘물질흐름분석 소프트웨어(STAN 2.5)를 활용하여 공정 내의 데이터 유입과 유출을 Shankey diagram 형태로 표현하였다. 연구 결과, 원자재 수은의 국내 유통량은 2014년 기준 국내 유입량은 약 3톤(제조량: 1 ton, 수입량: 2 ton)으로 집계되고 수입된 수은은 대부분 형광램프 제조(2.01 ton), 시약(0.76 ton), 촉매(0.12 ton) 등의 용도로 사용된 것으로 나타났다. 회수량은 문헌 조사 결과 수은 함유 부산물 및 폐기물 관리를 위해 도입되는 시나리오별 두 가지 기준을 적용하여 회수 가능량을 추정하였다. 시나리오에 따라 27.3 ton/yr, 25.4 ton/yr으로 예측하였다. 원자재 수은의 국내 재고량은 대략 0.5 ton/yr으로 보인다.
냉매는 냉동사이클을 형성하고, 냉각작용을 일으키는 매체로 산업용 냉동・공조기기, 에어컨, 냉장고 등 다양한 기기에 사용된다. 냉매는 편리한 물질이지만 냉매 중 대부분은 오존층 파괴 또는 온실효과 등 환경에 영향을 끼치는 물질이다. 냉매로 많이 사용되는 물질을 예로 들면, HCFCs는 오존층 파괴와 온실효과를 일으키고, HFCs는 오존층 파괴능력은 없지만, 교토협약에서 정한 6대 온실가스 중 하나에 속한다. 그래서 사용 전후로 냉매의 적정 관리나 처리가 중요하다. 하지만 관련법의 혼합한 부분과 관계자의 부적합한 대처로 냉매의 적정 관리와 처리가 이루어지지 않고 있다. 따라서 본 연구에서는 국내 냉매 관련법과 냉매 물질흐름도를 기반으로 관련 시스템 제도를 분석하고 문제점을 파악하여 적합한 냉매 관리 시스템 및 제도의 개선 방안을 제시하고자 한다. 국내법에서 냉매 관리 및 처리에 관련된 법은 ‘대기환경보전법’, ‘오존층 보호를 위한 특정물질의 제조, 규제 등에 관한 법률’, ‘폐기물관리법’, ‘전기・전자제품 및 자동차의 자원순환에 관한 법률’ 등이 있다. 이 법들은 단계별, 물질별, 제품별로 복합하게 이루어져 있다. 각 법들의 조문을 정리하여 관리 대상 물질 및 제품, 법에 해당하는 주체나 단계를 조사하였다. 이후 생산・수입단계, 사용단계, 회수단계, 처리단계로 분류하여 정리하였다. 냉매 흐름을 파악하기 위하여 냉매의 물질흐름도를 파악하였다. 그래서 연구를 진행하며 파악된 문제점 역시 주체별, 단계별로 정리하였다. 문제점들을 극복하기 위한 개선방안도 주체별로 분류하여 제시하였다. 냉매 관리에서 주요 문제점은 냉매 물질 모니터링 부재, 회수 및 처리 기준과 주체의 모호성, 관리 대상에서 일부 냉매물질 제외 등이 있다. 그에 따른 개선 방안으로는 주체별 역할의 강화 및 개선, 폐냉매 회수 및 처리 시스템 개선, 냉매 유지보수업자 등의 냉매 전문가 등록 및 자격 검증제도 도입 등이 있다. 본 연구는 문헌조사를 바탕으로 냉매 관리와 처리 시스템을 분석하여 개선방안을 제시하였다. 본 연구의 결과는 냉매의 친환경 시스템 및 정책 마련을 위한 기초 자료로 사용될 수 있다.
In recent years, waste-to-energy conversion using municipal solid waste (MSW) has been gaining attention in municipalities. Such conversion can reduce the dependency of non-renewable energy such as fossil fuels by generating solid refuse fuel (SRF) and diverting landfilling of the waste, although there is debate over the efficiency and economic aspect of the practice. With a growing interest in the conversion, D city is trying to adopt all possible measures towards achieving a material-cycle society by constructing a waste-to-energy town by 2018. The waste-to-energy town will be comprised of energy recovery facilities such as a mechanical treatment facility for fluff-type SRF with a power generation plant, and anaerobic digestion of food waste for biogas recovery. In this paper, we focus on estimating the energy recovery potentials and greenhouse gas (GHG) reduction of MSW by waste-to-energy conversion under three different scenarios. The data required for this study were obtained from available national statistics and reports, a literature review, and interviews with local authorities and industry experts. The lower heating value was calculated using the modified Dulong equation. Based on the results of this study, the energy recovery potential of MSW was calculated to be approximately 14,201-51,122 TOE/y, 12,426-44,732 TOE/y, and 8,520-30,673 TOE/y for Scenarios 1, 2, and 3, respectively. The reduction of GHG by such conversion was estimated to range from 10,074-36,938 tonCO2eq/y, depending on scenario. This study would help determine the production rate of fluff-type SRF to be converted into a form of energy. In addition, this study would aid waste management decision-makers to clarify the effectiveness of recycling of MSW and their corresponding energy recovery potentials, as well as to understand GHG reduction by the conversion.
In this study, the recycling processes of construction and demolition waste (C&D waste) were analyzed, and its national recycling rate was determined using material flow analysis (MFA). Available statistical data provided by Ministry of Environment and Korea Environment Corporation were used for the MFA study. The collected data were carefully examined and validated by field investigations. System boundary for MFA covered from waste generation from construction sites to final disposal in 2013. The field investigation showed that recycled aggregate is produced through mechanical shredding, separation, and screening processes of C&D waste. The production efficiency (or process yield) was estimated to be approximately 81.2% on average. The foreign materials in the waste accounted for 18.8% by weight. The separated impurities were sent to recycling facilities, incineration facilities, or landfill sites, depending on the physicochemical characteristics. Efficiency of recycling facilities and the statistical data were integrated to estimate the national actual recycling rate, which turned out to be 87.7% in 2013. Approximately 49.1% of the construction-related waste was recycled as recycled aggregate for concrete production and road base layer for asphalt pavement. Based on the result of MFA, there is 9.8% difference between the actual recycling rate in this study and reported recycling rate by national statistics. In the future, more various C&D waste treatment and disposal facilities, along with aggregate recycling facility, should be investigated to verify the actual recycling rate determined by this study. Statistical accuracy should be further refined through additional field investigations. Our findings can be applicable to development of recycling policies and best management practices for C&D waste streams.
Aluminum can is one of the common and economically valuable recycling items in municipal waste streams. In this study, the reduction rate of the greenhouse gas emission and energy savings were estimated when aluminum cans are recycled by using material flow analysis, US EPA WARM method, and EU Prognos method. Based on the results, approximately 16,630 ton of aluminum in 2010 was recovered as ingot, while 10,873 ton of aluminum can to can recycling occurred in the same year. The reduction rate of aluminum recycling was estimated to be 240,986 tCO2eq/yr by US EPA WARM method, while about 305,283 tCO2eq/yr was found by the recycling using EU Prognos method. The difference resulted partly from the different system boundary and the loss rate during aluminum recycling process. The results of the energy savings and greenhouse gas reduction rate would be valuable for waste management policy makers to estimate the potential reduction rate of greenhouse gas by aluminum can recycling and accelerate recycling infrastructure of waste streams. This study also implies that the applications and results of both methods to estimate greenhouse gas reduction rates by aluminum can recycling should be carefully reviewed and acknowledged before the use of the method due to the different assumptions and results that are anticipated.
With a growing concern of greenhouse gas (GHG) emissions due to climate change, many activities and efforts onthe greenhouse gas reduction have been implemented in solid waste sectors. Since recycling is the major managementoption for solid waste in Korea, it is important to estimate the reduction of the greenhouse gas emission during recyclingprocesses. In this study, two common methodologies, Prognos method of EU and waste reduction model (WARM) methodof USA, have been critically reviewed and compared to estimate the reduction for recycling of waste paper in terms ofsystem boundary, recycling processes, and emission factors. As a common point of two methodologies, the reductionfactors for the paper recycling have been developed by subtracting the recycled product emissions from the virgin productemissions to get the greenhouse gas savings. While the recycling losses and transportation are considered in twomethodology development, there are a number of differences between the methodologies in system boundary,transportation distance and forest carbon sequestration. As a result, it caused the difference in final greenhouse gasreduction factor of paper recycling. The reduction factor was −820kgCO2eq/ton in Prognos method, while −3,891kgCO2eq/ton was found in the WARM method. When both methods were applied to recycling of waste paper in Korea,the greenhouse gas reductions by the Prognos method and the WARM method were found to be 3,485.2tCO2eq/day and2,248.8tCO2eq/day, respectively. When the carbon sequestration by forest is considered in the WARM method, thereduction rate was estimated to be 16,538.3tCO2eq/day. The main reasons for such difference can be attributed to systemboundary and forest carbon sequestration. Especially, forest carbon sequestration can be an important factor in Korea thatusually manufactures papers from imported pulp from abroad. This study implies that the applications and results of bothmethods to estimate greenhouse gas reduction by waste recycling should carefully reviewed and acknowledged beforeuse due to the different assumptions and results that are anticipated.
Environmental concerns regarding mercury-containing fluorescent lamps have been raised in many countries, especiallyafter International Minamata Convention on Mercury in 2014. Improper management and disposal of the waste such aslandfilling and incineration may pose serious threats to the environment and human health. In Korea, mercury-containinglamps have been regulated by the expanded producer responsibility (EPR) system since 2004. However, only less than30% of the lamps sold to consumers has been collected by municipalities. In order to provide additional measures relatedto proper management of fluorescent lamps, there is a need for a quantitative material flow study by life cycle stage. Inthis study, material flow analysis was conducted by collecting relevant data from literature review, available statistics,and field site visits to lamp recycling facilities. According to the results of this study, approximately 150 million unitsof fluorescent lamps were put on the market in 2013, while 36.9 million units of the lamps were recycled mainly fromhouseholds in the year. It is estimated that approximately 3.5 million units and 2.3 million units of lamps in disposalbags are disposed and treated in landfills and incineration facilities, respectively. This study also found that there weresignificant amounts of uncollected lamps that were present in industrial sectors. The material flow of the industrial sectorsare largely unknown and not properly regulated by government. Based on the mass flow of mercury in lamps, 1.6ton ofmercury in lamps came into consumer markets in 2013. Approximately 407kg of mercury was collected by the recyclingprocess at the fluorescent lamps recycling facility. The mercury disposed in landfills and treated in incinerators were foundto be 38.3kg and 25.5kg, respectively. Further study may be warranted to focus the material and mercury flow of lampsin industrial sectors in order to accurately determine the final destination and disposal of such waste in the environmentbecause there are very few available statistical data regarding distribution flow and treatment of lamps in the sectors.
This study was initiated to examine the potential impacts on the environment during the management of food waste by anaerobic digestion in Daejeon Metropolitan City (DMC) that is built in 2017. The evaluation was based on both material flow analysis (MFA) and life cycle assessment (LCA). The MFA study was performed using STAN 2.5, while the LCA was conducted according to ISO standards by utilizing Total 4 LCA software with the incorporation of CML 2002 methodology. According to the LCA results, global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), and photochemical ozone creation potential (POCP) were found to be approximately 166 kg CO2-eq/ton of food waste, 0.43 kg SO2-eq/ton of food waste, 0.66 kg PO4 3−eq/ton of food waste, and 0.08 kg C2H4-eq/ ton of food waste, respectively. The disposal stage showed higher impact of GWP on the environment due to the landfilling of solid sludge and screening waste. In case of eutrophication potential, the treatment phase showed the highest impact on the environment, mainly because of the consumption of electricity. Based on the results of normalization, the highest environmental impacts was found in the treatment stage related to eutrophication potential. The results of LCA would provide policy-makers to identify and reduce potential environmental impacts associated with food waste to biogas conversion in DMC by life cycle.
Food waste, a putrescible form of waste, comprised of 30% of the total municipal solid waste stream in Daejeon Metropolitan City (DMC) in 2012. Proper management of food waste is a challenging task for local government. This study was conducted to determine material flows when treated food waste in various recycling facilities. Material flows in the recycling processes were collected by site surveys, field trips and discussion with operators and governmental employees. Material flow analysis (MFA) was conducted to quantify the flow of food waste from generation to disposal for the year 2012. MFA along with its mass transfer coefficients were determined based on the inputs, outputs and waste fluxes. According to the mass transfer coefficient results, treatment efficiency for the dry and wet feed manufacturing facility was found to be higher than other treatment facilities. Water consumption was higher for the composting site, resulting in large volume of wastewater (mass transfer coefficient 1.539). While large amounts of screening materials such as plastic, chopsticks, aluminum foils, and bottle caps were generated at the composting site, mass transfer coefficients (0.312) at the dry and wet feed facility were relatively high, implying effective treatment of food waste occurring. The results of this study help to facilitate waste management policy decision-makers in developing effective food waste management techniques in DMC.
The management of household hazardous waste (HHW), a component of municipal solid waste (MSW) has become a major of concern partly due to their potential toxicity upon disposal. Improper management of such waste can deteriorate the environment and cause serious damage to the human health. This paper discusses the current fundamental management practices, which include the generation rate, collection systems and treatment using the survey reviews of households and interviews held with experts in the Daejeon metropolitan city. Surveys of more than 378 people in Daejeon Metropolitan City were conducted to investigate the characteristics, generation rate, social behavior and awareness regarding disposal of HHW. The target items used in this study includes used lamps, used batteries, pharmaceuticals, and household pesticide chemicals. According to the survey conducted, the generation rates of HHW varied depending upon the dwelling type, collection system, and waste type. Apartment complex residents participated actively in source separation, using the established collection system with limited items (e.g., fluorescent lamps and batteries), while single family housing residents tend to store HHW at households. There is still a need for public awareness, detailed policies and legislation requiring source segregation at households, and better collection systems for HHW. The results of this study can be used for developing better management of HHW in municipal solid waste streams to prevent potential environmental impacts and human health risks.
Global increase in the demand for the new Electrical and Electronic Equipment (EEE) results in the rapid increase of waste electrical and electronic equipment (WEEE) (or electronic waste). Significant efforts on developing diverse WEEE recycling policy and programs such as extended producer responsibility (EPR), WEEE directive, and the restriction of the use of hazardous substances (RoHS) directive are being made by many developed nations. This study focuses on determining priority among proposed WEEE recycling policy research projects by a number of experts from academia, institutions and recycling industry using quality function deployment (QFD) method to better manage and recycle WEEE in Korea. In order to develop effective WEEE recycling policy, a total of 12 different WEEE recycling policy research projects were proposed by a total of 11 experts related WEEE recycling. Reliability and validity evaluation of the proposed projects were conducted, along with SPSS statistical software. By using the QFD method, a survey regarding potential problems, suggestions, and difficulties at several WEEE recycling facilities were conducted and evaluated. Evaluation of the proposed projects was made by house of quality (HOQ). In this study, proposed research projects with higher importance index include WEEE collection system, development of WEEE recycling guideline, and establishment of WEEE generation/collection/recycling national database. The QFD method employed in this study can be effectively used as a decision-making process tool in WEEE recycling policy and road map.
This paper presents the estimation of actual recyclable amounts and the evaluation of waste oil recycling processes atrecycling facilities using material flow analysis (MFA). The estimation of actual recycling rates through the processes ofwaste lubricating oils is a very important subject not only in the point of view oil recycling efficiency by energy conversionprocesses but also in the perspective of the recycling technology level. In this study, the recycling processes and recyclingrates of waste lubricating oil recycling facilities were evaluated by using a MFA approach, a total of 10 site visits anda total of 30 site questionnaires in Korea. The MFA methodology based on mass balance approach applied to identifythe inputs and outputs of waste oils during the recycling processes at waste oil recycling facilities. It is necessary todetermine the composition and flows of the input materials to be recycled and foreign substances in a waste recyclingfacility. A complete understanding of the waste flows in the processes along with the site visit and data surveys for therecycling facilities was required to develop a material flow for the processes and determine the process yield by differenttreatment methods (chemical distillation, vacuum distillation and high temperature pyrolysis). The results show that onaverage the process yields for chemical distillation, vacuum distillation, and high temperature pyrolysis were 89.9±7.7%,77.9±16.1%, and 57.9±9.3%, respectively. During the chemical distillation method, water in waste oils was a majorfraction (>50%), while the vacuum distillation method resulted oil large amounts of oil sludge produced during therecycling process. The process yields for different treatment methods depended upon several factors including the qualityof incoming waste oils, the type and operating conditions of recycling processes that are applied to. Based on the materialflow analysis in this study, the actual recycled amount of waste oil was estimated to be approximately 260,809 ton in 2011.
There are many stringent environmental regulations on the management of waste electrical and electronic equipments(WEEE) in most developed countries. WEEE directive aims at increasing collection and recycling rate of WEEE whereas,while the restriction of the use of certain hazardous substances (RoHS) aims at restricting hazardous materials duringthe production of electrical and electronic equipment (EEE). TV housing rear covers consist of small portion of brominatedflame retardants (BFRs). Improper management and disposal of such waste can pose impacts on the environment andhuman health. In Korea, there are very few available statistical data regarding BFRs levels in TVs housing rear covers.In order to provide additional measures related to management of BFRs, there is a need for a quantitative material flowstudy on the amount of BFR found in TVs. This can be achieved by the aid of material flow analysis of the TV setsand by studying the Deca-BDE components present in the TV housing read covers. In this study, the relevant data werecollected from the statistical reports and through field site visits to the WEEE recycling facilities with surveys. Staticand dynamic material flow analysis (MFA) was conducted to determine material flow of BFRs (Deca-BDE) in themanagement of waste TVs. According to this study, in 2011, households in Korea use 73,821ton of TV sets of which23,592ton of waste TV sets were collected and recycled by municipalities and producers. Extended ProducerResponsibility (EPR) played a major role in recycling of WEEE. In this study, it was predicted that Deca-BDE in usestage would reach down to 51.73ton by 2016. In addition, the amount of Deca-BDE present at the disposal and recyclingstage is estimated to be approximately 2.45ton by 2018.