A study on the denitrification of reverse osmosis(RO) concentrated wastewater from sewage reuse treatment plant in P city was conducted using waste desulfurization agent obtained from desulfurization process. Sulfur-based autotrophic denitrifying carrier comprises the predetermined amount of waste iron sulfide (FeS, Fe2S3), mine drainage sludge and elemental sulfur showing mesoporisity with 9.9 nm (99 Å) of average pore size. Sulfur denitrifying bacteria and sulfur reducing bacteria were implanted into the pores of sulfur denitrifying carrier. Nitrate was not affected by empty bed contact time (EBCT). It is probably due to larger reducing capacity of the carrier than the concentration of nitrate in RO concentrated wastewater. Total nitrogen (T-N) removal efficiency exhibited about 90% after 4 days. Sulfate ion was surprisingly decreased with sulfur autotropic process due to the reduction of sulfate ion to HS- and S2- by sulfur reducing bacteria. Sulfide and hydrogen sulfide ions were then taken by Fe(OH)3, main component of mine drainage sludge, releasing OH-. Alkalinity was therefore maintained between 7.5 and 8.5 in pH by the released OH-. Also, it had the effect of suppressing the production of H2S, which causes bad odor.

This study investigated the relationship between service quality factors, customer satisfaction, and reuse intention based on the degree of attachment to companion animals felt by caregivers when using dog grooming services. An online and offline survey with caregivers experienced in dog grooming services were conducted, and 304 responses were analyzed using SPSS 26.0 Statistics Program. The analysis revealed the following. First, sub-factors of dog grooming service quality: empathy, assurance, tangibles, and reliability, significantly affect customer satisfaction. Second, customers satisfaction with dog grooming services significantly affects their reuse intention. Third, only reliability demonstrates a moderating effect on attachment to companion dogs in influencing the relationship between customer satisfaction and service quality. These findings that service quality management is necessary to improve the business performance of dog-grooming services. Particularly, this study is meaningful in presenting the direction of service marketing centered on trust, as more guardians consider companion dogs as family.

가상현실과 현실 세계를 융합한 공간으로서 가상의 세계 안에서 다양 한 상호작용과 경험을 제공하는 메타버스 서비스는 사용자들이 자아일치 성을 공유하고 강화하는 공간을 형성해줄 수 있다. 본 연구에서는 메타 버스 서비스 특성이 사용자의 재이용의도에 미치는 영향과, 이 관계를 매개하는 자아일치성의 효과를 검증하였다. 메타버스 서비스를 이용해 본 경험이 있는 성인 남녀를 대상으로 수집한 245개 설문자료를 분석한 결과에 따르면 메타버스 서비스 특성 중 실재감과 매개변수인 자아일치 성은 고객의 메타버스 재이용의도에 긍정적인 영향을 미치는 것으로 나 타났다. 또한 매개효과분석 결과에 따르면 자아일치성은 메타버스 서비 스 특성 중 실재감과 재이용의도 간의 관계를 부분매개하고, 유용성과 재이용의도 간의 관계, 상호작용성과 재이용의도 간의 관계를 완전매개 하는 것으로 나타났다. 연구 결과는 변화된 환경과 소비자 특성으로 인 해 전통적 브랜드 마케팅 방식의 한계에 직면하고 있는 기업들에게 메타 버스를 활용한 마케팅 전략 도출에 도움이 되는 유용한 정보를 제공하고 있다.

To compete with the growth of fashion shopping platforms in the online fashion market, general shopping platforms have begun to expand their product categories to include fashion items. This research examines the characteristics that influence consumers’ trust in each of these platforms and their intention to reuse them. Applying the concept of platforms, this study also distinguishes between general shopping platforms and fashion shopping platforms and compares their characteristics. This study surveyed 788 consumers in their 20s and 30s with experience in using general shopping platforms or fashion shopping platforms (389 and 399 respondents, respectively). SPSS was used to conduct frequency analysis, factor analysis, and cross-tabulations, and AMOS was used to conduct confirmatory factor analyses and structural equation analyses. The results were as follows: platform reputation, shopping convenience, and interactivity all influenced consumer trust. For fashion shopping platforms, the product quality factor significantly improved consumer trust. However, for general shopping platforms, the product quality factor only influenced reuse intentions to reuse and did not contribute to improving trust. Platform reputation and information offering have influenced reuse intentions for both shopping platforms. Regardless of the type of shopping platform, platform reputation has influenced reuse intentions and consumer trust, and platform esthetics didn’t have affect consumer trust and consumers’ reuse intentions. Consumer trust influenced the intention to reuse on both platforms.

본 연구에서는 파프리카(Capsicum annuum L.) ‘Scirocco’ 품종 수경재배 시 배액 재사용 여부에 따른 순환식 재배와 비 순환식 재배 및 배지 종류가 배액의 양분 이온 변화 양상과 생 육에 미치는 영향을 조사하였다. 파프리카의 파종은 2021년 8 월 19일에, 정식은 2021년 9월 16일, 순환식 및 비순환식의 재 배 방식 적용은 2021년 10월 21일에 시행하였다. 배액 내 양 분 분석 결과, Na+와 Cl‒은 작물이 제대로 흡수하지 않는 대표 적은 이온으로써 생육이 진전될수록 순환식 재배방식에서 집 적되었다. 또한 배액 내 NH4-N의 함량이 NO3-N의 함량에 비 해 현저히 낮으므로 파프리카의 이온 선택성으로 인해 NO3-N 보다 NH4-N이 우선 흡수되는 것으로 생각된다. 파프리카의 생육 및 과실 특성은 배액 재사용 여부와 배지의 종류에 따른 처리 간의 차이가 크지 않았다. 결론적으로 순환식과 비순환 식의 수경재배 방식, 코이어와 암면의 배지 종류에 따른 파프 리카 수경 재배 시 중기 이후의 세력 약화로 인한 착과 불량을 유의하여 관리한다면 처리 간의 차이가 크지 않으므로 농가의 실정에 맞는 재배 방식과 배지를 선택하여 파프리카를 생산할 수 있을 것으로 생각된다. 다만 최근 환경오염에 대한 관심이 높아진 만큼 배액 재사용에 따른 병원균 감염 등을 잘 관리한 다는 가정 하에서 순환식 재배 방식을 채택해도 수량 감소나 품질 저하 등은 우려하지 않아도 될 것이라 판단되며, 폐기 문 제가 발생하는 암면 대신 코이어 배지를 선택한다면 더욱 환 경오염 감소에 기여할 수 있으리라 기대된다.

본 연구에서는 하수 재이용을 위한 역삼투막 공정에서 전처리 정밀여과막(MF) 손상에 대한 누출되는 다양한 수 질변화로써 막 손상 검지 방안을 제시하였다. 이를 위하여 역삼투막 유입수질 적합성 평가지표인 SDI (silt density index)를 3에서 5의 범위 내에서 막 손상 시 검지 감도를 정량화하기 위하여 전처리 분리막이 1에서 3가닥 파단에 따라 SDI는 1.92에 서 6.11까지 증가한 결과를 확인할 수 있었다. 일반적으로 3을 기준으로 역삼투막 유입수질로 설정하였을 때 분리막이 3가닥 까지 파단이 되어야만 막 손상 검지가 가능하다는 것을 의미하며 역삼투막의 오염은 잠재적으로 가속화되어 효율을 저하시 킬 수 있다. 또한 이때 누출되는 입자성과 유기물질에 대하여 0.45 μm 이상의 크기만 걸러주는 입자계수는 입도분포별 막 파 단 개수에 따라 일정한 패턴을 확인할 수 없었으며, TOC 농도는 약 2배의 변화패턴으로써 SDI와의 상관관계로써 TOC가 막 손상 수질지표로써 신뢰성이 높은 것으로 확인되었다. 수질분석결과와 더불어 USEPA에서 제시하는 막 손상 검지 방법 중 압력손실시험과 이를 기반으로 LRVDIT 모델의 적합성 평가를 한 결과 막 손상 또는 역삼투막 공정으로 유입되는 막오염물질 을 신속하게 확인할 수 있는 SDI 및 TOC를 포함한 LRVDIT 모니터링과 UCL 설정을 병행해야 한다.

Due to the global climate change, Korean peninsula is has been experiencing flooding and drought severely. It is hard difficult to manage water resources sustainably, because due to intensive precipitation in short periods and severe drought has increased in Korea. Reused water from the wastewater treatment plant (WWTP) could be a sustainable and an alternative water source near the urban areas. In order to understand the patterns of water reuse in Korea, annual water reuses data according to the times and regional governments were investigated from 2008 to 2019. The reused water from WWTP in Korea has been mainly used for river maintenance flow and industrial use, while agricultural use of water reuse has decreased with time. Metropolitan cities in Korea such as Seoul, Busan, Daegu, Ulsan, and Incheon have been mainly used reused reusing water for river maintenance flow. Industrial water reuse has been limitedly applied recently for the planned industrial districts in Pohang, Gumi, Paju, and Asan. By using the collected annual water reuse data from the domestic sewerage statistics of sewerage, the optimistic and pessimistic future estimations of for future annual water reuse were suggested from 2020 to 2040 on a five year interval for every five years.

Project Management Information System (PMIS) is a special purpose information system that is created to provide useful information for project managers and participants to make effective and efficient decision making during projects. The use of PMIS is increasing in project based industries such as construction, defense, manufacturing, software development, telecommunication, etc. It is generally known that PMIS helps to improve the quality of decision making in project management, and consequently improves the project management performance. However, it is unclear what are the difference of PMIS impacts between industries, and still need to be studied further. The purpose of this study is to compare the impact of PMIS on project management performance between industries. We assume that the effects of PMIS will be different depending on the industry types. Five hypotheses are established and tested by using statistical methods. Data were collected by using a survey questionnaire from those people who had experience of using PMIS in various project related industries such as construction, defense, manufacturing, software development and telecommunication. The survey questionnaire consists of 5 point scale items and were distributed through e-mails and google drive network. A total of 181 responses were collected, and 137 were used for analysis after excluding those responses with missing items. Statistical techniques such as factor analysis and multiple regression are used to analyze the data. Summarizing the results, it is found that the impacts of PMIS quality on the PM performance are different depending on the industry types where PMIS is used. System quality seems to be more important for improving the PM performance in construction industry while information quality seems more important for manufacturing industry. As for the ICT and R&D industries, PMIS seems to have relatively lesser impact compared to construction and manufacturing industries.

Seaweed by-products have been dumped into the sea and induced marine pollution. However, they can be recycled as a valuable natural resources. Approximately 240,000 tons of sea mustard and kelp by-products were estimated to be producted during the last three years. The estimate corresponds 6.7% of the total production of marine aquaculture and 14.9% of the total production of seaweeds. When adding up the by-products from fish and mollusks, approximately 1,000,000 tons of fisheries by-products were thrown out into the sea every year. A three-step strategy is required for the industralization of fisheries by-products. The first step is the construction of the processing foundation of by-products, the second is its food industralization, and the third is its recycling as raw biomaterials. The stable supply of raw materials is the prerequisite for the industralization. Thus, it is necessary to construct the refuse logistics around chief production districts and to build the processing facility and frozen storage of by-products. Cooperation among private enterprises and government investment for research and development is required the second and third steps.

본 연구에서는 하수처리유출수의 유기물 성상을 제어하기 위해 서로 다른 흡착제를 적용하여 역삼투막의 막오염 경향성을 관찰하였다. 실험실 규모에서 역삼투막 운전결과, 다중벽탄소나노튜브 (5%), 팽창흑연 (21%), 하수처리유출수(25%), 활성탄 (26%) 순서로 초기대비 투과수량이 감소하였다. 형성된 막오염 물질의 FEEM 분석결과, 활성탄의 경우 팽창흑연, 다중벽탄소나노튜브, 하수처리 유출수에 상대적으로 높은 미생물유래물질에 의한 막오염이 존재하였다. 더 나아가, 분자량 분석 결과를 통해 고분자 미생물유래물질(>15K Da)의 영향이 큰 것을 확인하였다. 결과적으로, 하수재이용공정에서 고분자 미생물유래물질이 역삼투막 효율저하의 주요한 역할을 하며, 이를 저감시키기 위한 방안마련이 필요하다고 판단되었다.

In this study, various physical cleaning methods such as physical washing and osmotic backwash, were performed to understand membrane fouling characteristics by employing real secondary wastewater effluent (SWWE). In addition, microfiltration (MF) and ultrafiltration (UF) pretreatments were compared to maximize removal of organic matter and to control membrane fouling efficiently. Organic foulants deposited on the active layer of FO membrane were observed by fouling behavior test. The relationship between concentrations of natural organic matter and membrane fouling was also investigated from the bench-scale FO tests. Finally, by quantitative analysis of correlations between foulants and fouling reversibility with the modified fouling index (MFI), we identified the applicability of MFI in predicting FO intake water fouling potential.

인구구조 및 생활방식 등의 변화로 물 소비는 증가되고 있는 반면, 가뭄 등 기후변화로 가용수자원 여건은 악화되고 있어 안정적인 용수공급의 필요성이 증대되고 있다. 우리 정부는 물의 재이용 촉진 및 지원에 관한 법률을 제정하고 하수처리수 재이용, 중수도, 빗물이용 등 지속가능한 물 순환을 추진하며 지역적 물 부족을 해소하기 위하여 노력하고 있다. 정부는 물 재이용 관리체제를 강화하고 시설기반을 구축하는 한편 관련 산업 육성과 전문인력 양성을 위해 노력해 왔다. 하지만 국내 물 재이용은 여러 가지 정책⋅재정⋅기술적 한계로 인해 계획대비 더디게 진행되고 있어 물 재이용 방향성의 재정립이 필요하다. 이에 본 발표를 통해 물재이용의 방향에 대하여 하수처리수 재이용을 중심으로 제언하고자 한다.