Recent progress in microalgal biomass production coupled with wastewater treatment for biofuel generation

Salama, El-Sayed,Kurade, Mayur B.,Abou-Shanab, Reda A.I.,El-Dalatony, Marwa M.,Yang, Il-Seung,Min, Booki,Jeon, Byong-Hun Elsevier 2017 RENEWABLE & SUSTAINABLE ENERGY REVIEWS Vol.79 No.-

<P><B>Abstract</B></P> <P>Microalgae are a potential source of sustainable biomass feedstock for biofuel generation, and can proliferate under versatile environmental conditions. Mass cultivation of microalgae is the most overpriced and technically challenging step in microalgal biofuel generation. Wastewater is an available source of the water plus nutrients necessary for algae cultivation. Microalgae provide a cost-effective and sustainable means of advanced (waste)water treatment with the simultaneous production of commercially valuable products. Microalgae show higher efficiency in nutrient removal than other microorganisms because the nutrients (ammonia, nitrate, phosphate, urea and trace elements) present in various wastewaters are essential for microalgal growth. Potential progress in the area of microalgal cultivation coupled with wastewater treatment in open and closed systems has led to an improvement in algal biomass production. However, significant efforts are still required for the development and optimization of a coupled system to simultaneously generate biomass and treat wastewater. In this review, the systematic description of the technologies required for the successful integration of wastewater treatment and cultivation of microalgae for biomass production toward biofuel generation was discussed. It deeply reviews the microalgae-mediated treatment of different wastewaters (including municipal, piggery/swine, industrial, and anaerobic wastewater), and highlight the wastewater characteristics suitable for microalgae cultivation. Various pretreatment methods (such as filtration, autoclaving, UV application, and dilution) needed for wastewater prior to its use for microalgae cultivation have been discussed. The selection of potential microalgae species that can grow in wastewater and generate a large amount of biomass has been considered. Discussion on microalgal cultivation systems (including raceways, photobioreactors, turf scrubbers, and hybrid systems) that use wastewater, evaluating the capital expenditures (CAPEX) and operational expenditures (OPEX) of each system was reported. In view of the limitations of recent studies, the future directions for integrated wastewater treatment and microalgae biomass production for industrial applications were suggested.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Challenges in using wastewater for microalgae cultivation and biomass production. </LI> <LI> Treatment of different wastewaters and reuse of the treated water. </LI> <LI> Recovery of valuable nutrients (N/P) and removal of organic pollutants. </LI> <LI> Application of wastewater in raceways, photobioreactors, turf scrubbers, and hybrid systems. </LI> <LI> Genetically engineered microalgae for efficient wastewater treatment. </LI> </UL> </P>

업종별 산업폐수 TOC 처리특성 연구(총설) - 업종별 산업폐수 TOC 처리현황 및 오존 /고도산화에 의한 TOC 처리특성

김경진,전정호,염익태 대한환경공학회 2023 대한환경공학회지 Vol.45 No.1

Purpose: As the organic pollutant indicator is changed from CODMn to TOC and the demand for TOC treatment of industrial wastewater increasing, the current situation of TOC treatment of wastewater discharge facilities of each industrial category is analyzed, and it is intended to consider the possibility of residual TOC treatment by ozone and advanced oxidation process. Method: To review the TOC treatment situations of wastewater discharge facilities of each industrial category, the field survey data (46 sites) by Environment Ministry and Korea Environment Corporation were analyzed according to inflow TOC concentrations, direct/indirect discharge type, and main treatment process of wastewater treatment facilities. To review the characteristics of TOC treatment by ozone and advanced oxidation processes, previous studies and the results of field pilot tests conducted by ozone companies were comprehensively analyzed. Results and Conclusions: The TOC treatment level varies depending on the inflow TOC concentrations to each industrial wastewater treatment facility, direct/indirect discharge type depending on the location of the wastewater treatment facilities, and the main treatment process of the wastewater treatment facility. In particular, the TOC removal rate differed by more than 20% depending on the presence or absence of biological treatment. The wastewater treatment facilities that require additional treatment of residual TOC were divided as follows (1) when the facility has biological treatment as main process, increasing unexpected inflow TOC load in treatment facilities or the condition of the biological treatment become worsen. (2) when the facility has phy-chemical treatment as main process, increasing unexpected inflow TOC load. (3) extending the replacement cycle of activated carbon to save maintenance cost. Therefore, for additional TOC treatment, it is necessary to secure the stability of the main process in preparation for load fluctuations and to apply post TOC processing suitable for the characteristics of the main treatment process. The direct oxidation reaction of ozone forms intermediate products such as carbonyl groups and carboxyl groups and hydrogen ablation are difficult to convert to inorganic carbon, and the advance oxidation process decomposes easily by OH radicals through the radical substitution of unsaturated hydrocarbons and aromatic compounds, so the removal rate of TOC by the O3+H2O2 advanced oxidation pilot test was 14.7∼93.5%, higher than that of ozone oxidation. The specific ozone consumption per TOC removal amount (O3/ΔTOC) by O3+H2O2 advanced oxidation is 8.5~22.5mgO3/mgTOC, which is 1/5 of that of ozone oxidation, so the advanced oxidation process is suitable for removing residual TOC of industrial refractory wastewater. In addition, comparing ozone consumptions by ozone & O3+H2O2 advanced oxidation to remove CODMn and TOC, ozone consumption of O3+H2O2 advanced oxidation to remove TOC is 2.7 to 4.3 times compared to that by O3 oxidation to remove CODMn and ozone consumption of ozone oxidation to remove TOC increased by 13.3 to 21 times than that by O3 oxidation to remove CODMn. Therefore, when introducing the TOC additional treatment process the different treatment characteristics of CODMn and TOC should be considered. 목적: 배출허용기준 유기물 지표가 CODMn에서 TOC로 전환되고 업종별 산업폐수 TOC 처리에 대한 요구가 증가됨에 따라 기존 업종별 산업폐수 배출시설 TOC 처리현황을 분석하여 추가 TOC 처리 필요성을 검토하고 대표적인 산화공정인 오존 및 고도산화 공정에 의한 잔류 TOC 처리 가능성을 고찰하고자 한다. 방법: 업종별 산업폐수 TOC 처리현황을 검토하기 위해 환경부, 한국환경공단에서 법제화 및 기술지원 과정에서 수행된 업종별 현장조사 자료(46개 사업장)들을 유입 TOC 농도, 직접/간접 방류유형, 그리고 폐수처리시설 주처리공정에 따라 분석하였고, 오존 및 고도산화 공정에 의한 TOC 처리특성을 검토하기 위해 선행연구 및 오존 전문업체 수행했던 현장 pilot test 결과를 종합적으로 분석하였다. 결과 및 결론: 업종별 유입 TOC 농도와 폐수배출시설 입지에 따른 직접/간접 방류유형, 그리고 폐수처리시설 주처리공정에 따라 TOC 처리율에 차이가 발생하며 특히 생물학적 처리 유무에 따라 TOC 제거율이 20%이상 차이가 나타났다. 잔류 TOC 추가처리 필요하는 처리시설들은 (1)생물학적 처리가 주공정인 배출시설에서 유입부하 증가 또는 생물반응조 상태가 악화 시 초과 배출되는 TOC 저감, (2)물리화학적 처리가 주공정인 배출시설에서 유입 부하증가 시 초과 배출되는 TOC 저감, (3) 후단 활성탄 흡착공정으로 TOC 제거하는 배출시설에서 활성탄 교체주기 연장(유지관리비 절감)을 위한 TOC 부하저감으로 구분되었다. 따라서 추가 TOC 처리를 위해서는 부하변동에 대비한 주처리 공정의 처리 안정성 확보 및 주처리공정의 특성에 맞는 후단 TOC처리시설 도입이 필요하다. 오존의 유기물 직접 산화반응은 카보닐 그룹이나 카복실 그룹과 같은 중간 생산물을 형성하고 수소제거 반응(Hydrogen abstraction)이 어려워 무기화가 제한적이며 고도산화공정은 OH라디칼이 불포화 탄화수소 및 방향족 화합물등을 라디칼 치환하는 경로를 통해 쉽게 분해할 수 있으며 실제 O3+H2O2 고도산화 Pilot Test에 의한 업종별 발생폐수 TOC 제거율은 14.7∼93.5%로 오존단독에 비해 높게 나타났으며, O3+H2O2 고도산화에 의한 TOC제거량당 오존소모량(O3/ΔTOC)는 8.5∼22.5mgO3/mgTOC로 오존 단독처리에 비해 1/5 정도로 적게 소모되어 난분해성 폐수 잔류 TOC 제거를 위해서는 고도산화 공정이 적합하다. 또한 오존산화 및 고도산화에 의한 CODMn과 TOC 처리특성을 검토한 결과, 오존산화로 TOC를 처리할 경우 오존소모량은 오존산화로 CODMn 제거위한 오존소모량의 13.3∼21배 증가하였고 O3+H2O2 고도산화로 TOC를 처리할 경우에는 오존산화로 CODMn을 처리하기 위한 오존소모량에 비해 2.7∼4.3배 증가된 것으로 분석되어 TOC 추가처리 공정 도입 시 CODMn과 TOC의 처리특성 차이를 고려해야 한다.

Status, Trend and Strategy on Municipal Wastewater Management in China

Wang Baozhen,Wang Lin,Liu Shuo,Wang Li,Wang Zheng 한국습지학회 2007 한국습지학회지 Vol.9 No.1

The rapid development of economy in China at the expense of consuming huge amount of energy and resources, water resource in particular, which has resulted in the production and discharge of increasing amount of wastewater to the water environment. In order to effectively control the increasing water pollution trend, the State Council has stipulated that all the cities with population over 500,000 should reach wastewater treatment rate of 60% by 2005, and all the cities should reach the rate of 60% by 2010, of which Capital Beijing and all the province capital cities and important tourism cities should reach 70% then. By the end of 2005, of the 661 cities in China, 393 have built and operated municipal wastewater treatments with a total number of 790 sets, total treatment capacity of 80.91×106 m3/d and total treatment rate of > 48%. Other 73 cities have started the construction of municipal wastewater treatment plants, and other 168 cities have started to prepare, planning and design of wastewater treatment plants. Most of municipal wastewater treatment plants in big cities in China operate normally and perform well with good quality of effluent in terms of wastewater treatment train, but the sewage sludge treatment is usually poor with big problems. It has been found that the small scale WWTPs using activated sludge process in the towns are usually operated and maintained abnormally because of lack of fund, skilled operators and energy. It is therefore suggested that the small scale MWWTPs in small cities and towns adopt appropriate technologies, of which the most available ones are multi-stage ponds, constructed wetlands and the combination of them for further purification and reuse of treated wastewater.

공공수역 수질개선을 위한 공공하수처리시설 관리제도의 합리적 개선방안 연구

김익재 ( Ik Jae Kim ),김호정,한대호,김교범,곽효은 한국환경정책평가연구원 2017 기본연구보고서 Vol.2017 No.-

그동안 수질오염원관리에 지대한 역할을 한 공공하수처리시설의 여러 한계점들이 최근 부각되고 있다. 공공수역의 수질개선이라는 큰 틀에서 여러 한계점들을 진단하면 제도적 혹은 기술적 개선점으로 크게 구분할 수 있을 것이다. 그 중 생분해성 유기물질 외에도 공공수역의 물환경에 큰 영향을 미치는 기존 또는 신규 화학물질에 대한 하수처리시설의 관리개선은 그 공통분모로 볼 수 있다. 많은 선진국은 중금속, 의약물질 및 개인위생물질(PPCPs)등과 같은 미량유해물질이 하수처리시설로 유입·배출되는 경로를 이미 제도를 통해 적정하게 관리하고 있거나 모니터링을 추가 확대하여 공공수역의 물환경 건강성과 국민의 건강보호를 위해 정부 차원에서 다양한 노력을 펼치고 있다. 더 나아가 유럽은 미규제물질에 대한 목록을 선정하여 집중관리대상의 우선순위를 선정하는 등 공공수역의 수질보호와 하수처리시설 관리제도의 선진화 추세를 보이고 있다. 반면 우리나라의 현행 하수처리장 관리제도는 산업폐수 연계처리 등의 원인으로 유입·방류되어 물환경 위해성 가중시키는 (독성)화학물질에 대한 기준은 부재하고, 관련 제도 수립을 위한 현황조사도 초기단계 수준에 머물고 있다. 현행 ‘산업폐수의 공공하수처리시설 연계처리 지침’은 공공하수처리장으로 산업폐수 연계처리를 허용하여 시설 중복투자를 막는 경제적 인센티브를 부여하고 있고, 산업체 및 지자체의 비용절감을 유도하기 위해 낮은 배출허용기준을 적용하는 혜택을 부여하고 있다. 그러나 매년 산업폐수 연계처리 유입량은 증가하는 추세이고, 유입되는 수질오염물질의 종류나 농도는 제도의 부재로 조사가 거의 되지 않고 있는 실정이다. 또한 특정 수질유해물질 등에 대한 대상물질도 지속적으로 추가되고 있고, 녹조와 같은 수질악화를 예방하기 위해서 총인(TP)과 같은 방류수수질 기준농도는 강화했으며, 하수처리수 재이용도 권장하고 있지만, 오히려 공공수역 및 친수용수의 수질위해성과 깊은 연관되어 있는 하수처리방류수 혹은 수질오염원 관리의 개선은 아직 많이 미흡한 것으로 판단된다. 본 연구는 이러한 공공수역 수질개선 측면의 현행 하수처리시설의 제도적 한계점을 상세히 분석하고 또한 공공수역 수질오염원의 규제 강화 순응도에 대한 주제를 균형적 시선으로 추진하였다. 특히 본 연구는 공공하수처리장으로 유입된 후 적정한 관리기준의 부재로 공공수역으로 방류되는 오염물질의 거동을 중금속 중심으로 살펴보았다. 즉 공공하수처리시설로 연계처리되는 산업체의 현황을 분석하여 현재 공공수역으로 유입되는 폐수 배출 업소 및 오염원 배출 현황을 조사하였고, 공공수역의 오염 실태를 확인하기 위해 지자체에서 실제 운영 중인 공공하수처리장에서 발생한 슬러지의 성분을 분석하여 중금속 등에 대한 오염 현황 조사를 수행하였다. 본 보고서의 각 장별 주요 연구내용과 결과는 다음과 같다. 보고서의 2장에서는 공공수역의 수질개선을 위한 국내외 공공하수처리장의 현황 및 제도를 살펴보고, 이를 통한 시사점을 다루었다. 우리나라는 공공하수처리장의 BOD 유입부하 관리 및 저감에 집중하여 법적기준에 부합하는 처리수를 방류하고 있다. 최근 EU 등 선진국은 하수처리장 방류수질을 포함하여 신규 수질오염물질이 공공수역에 미치는 위해성을 인지하고, 관심 또는 우선관리 오염물질(watch list, priority pollutants)로 지정하는 등 엄격한 수준의 오염원 체계로 발전하고 있음을 알 수 있다. 따라서 우리나라도 각종 형태의 화학물질을 함유하여 처리장으로 유입되는 오염원 검토 및 위해성 평가를 위한 제도개선 검토를 서둘러야 할 것으로 사료된다. 3장에서는 제도적인 측면의 접근을 통해 국내 공공하수처리장 관리정책의 현황과 한계점을 제시하였다. 특히 공공하수처리시설로의 연계처리 지침에 대해 정리하였으며, 「하수도법」, 「수질 및 수생태계에 관한 법령」 및 배출허용기준 등을 상세하게 살펴보고, 각각의 법에서 충돌하는 부분에 대한 수정(안)을 제시하는 등 제도적 한계점으로 인해 발생하는 공공수역의 오염에 대한 연구를 수행하였다. 특히 연계처리 지침에서 제시하는 배출허용기준 ‘나’ 기준 적용으로 인해 중금속 및 특정 수질유해물질에 대한 기준 항목이 배제됨으로써 수질오염이 발생할 가능성이 높다. 또한 연계처리는 폐수처리시설 및 공공하수처리시설의 방류수 수질기준과 비교하여 상대적으로 완화된 것으로, 이를 악용하는 폐수배출시설이 존재할 것이다. 연계처리 시 효율적인 전처리 운영방안, 유역하수도 정비계획과 총량제방류수 수질항목에서 중금속 항목의 도입 등을 신중하게 검토할 필요가 있다. 4장에서는 공공수역을 오염시키는 배출시설에 대한 특성을 구체적으로 분석하였으며, 연구의 주요 결과로 산업계 하수처리장 연계처리를 수행하는 지역 및 처리규모별 현황을 분석하였다. 또한 ‘전국오염원조사자료’를 이용하여 전국 산업체 5만 8,711개소(2015년 기준) 중 연계처리 업소 1만 7,325개소(31.1%)에 대하여 중금속 함유 여부 및 배출허용기준(‘나’기준) 초과 대상 산업체에 대한 분석을 실시하였다. 전체 배출업소의 약 4.2%가 중금속함유 폐수를 하수처리장으로 연계하는 것으로 나타났다. 폐수를 간접배출하는 업소는 폐수처리 전과 후 대부분 중금속 항목에서 그 수가 미미하거나 비율이 낮았으나 연계처리하는 산업체는 구리 2,094개소(연계처리 배출업소수의 12.1%)로 나타났다. 또한 3개의 지자체에서 하수처리장 탈수슬러지의 유해물질을 시험한 결과, 하수슬러지 내에 중금속이 다량 검출된 것을 알 수 있었다. 이는 중금속이 최소한 산업폐수 연계처리에 간접적 영향을 미치는 것으로 볼 수 있으며, 하수처리과정에서 발생한 슬러지와 방류수는 공공수역에 심각한 영향을 미치는 오염원이라고 판단된다. 이러한 위험성의 향후 대응을 위해 하수처리시설 공법별 처리효율을 나타내었다. 본 연구는 오염 발생 원인자 및 발생 오염원에 대한 모니터링 및 원인 규명에 대한 접근으로도 정책적 활용에 의미를 가진다. 덧붙여 공공수역의 수질개선을 위하여 공공하수처리장, 물재이용, 그리고 관련 통계수집 및 생산의 관점에서 제도적 개선점을 제언하였다. 덧붙여 2011년 마련된 산업폐수의 연계처리 지침 개정을 위한 주요 내용안을 제시하였으며, 중금속 및 미규제 신규물질에 대한 해외 선진국의 규제 동향을 정리함으로써 이를 근거로 향후 우리나라에 미규제 신규물질의 규제 및 방류수 수질기준 선진화를 위한 정책도구로 활용될 수 있는 정책방향을 제시하였다. In surveying of water quality and the public wastewater treatment, particularly on the industrial wastewater treatment, there are two pillars of challenges: technical inefficiency and institutional indolence. As the amount of public sewage treatment combined with industrial wastewater continue to increase, the institutional safety nets to patrol and execute the violation activities are inadequate, resulting a cycle of contamination. In Korea, with the increasing demand of the public awareness, the discharged water quality standards have been continued to addressed. With a stronger regulation, a range of chemical substances threatening water quality have been annexed. However, the violation cases of the reinforced environmental laws and ordinances have continued appeared due to the lack of enforcement and compliance with regulations of wastewater discharges. These violations can be a direct and potential risk factor to the water pollution in the public water system, further the public health. In terms of the management system of developed countries, management of new chemical substances such as heavy metal discharge and micro pollutant are throughly discussed and regulated when establishing environmental policy for public sewage treatment facilities. Furthermore, it is a trend indicating the advancement of water quality standards of discharged water by selecting a list of unregulated materials and prioritizing concentration target. This study investigated the behavior of contaminants released into public waters due to the lack of appropriate management standards after entering the public sewage facilities. In particular, we surveyed the current status of public sewage treatment facilities and pollutant sources flowing into public water system. In order to confirm the contamination status of public water quality, pollution status of heavy metals was surveyed through a sludge analysis at the public sewage treatment facilities. Through the “Guideline for the Linkage of Public Sewage Treatment Facilities of Industrial Wastewater”, the public sewage treatment facilities were allowed to be indirectly discharged, thereby preventing the overlap of financial resources on investment. However, the application of permissible low emission limits to induce cost savings for industry has caused the yearly increases in pollutant loads in the public sewage treatment facilities. This study analyzed the institutional limitations and carried out a study on the institutional adaptation and improvement as a balanced perspective of strengthening regulation of public water quality. The major contents of this report are as follows. In Chapter 2 of the report, the status and system of public sewage treatment facilities for improving the quality of water in the public waters were examined and implications were discussed. In Chapter 3, we have conducted the study on, the current status and limitation of public sewage management policies through the legal framework. We examined in detail of the “Sewage Law (act 14839, 2017)”, “The Law on Water Quality and Aquatic Ecosystems (act 14490, 2016)”, and the “Emission Standards (regulation 688, 2017)”in order to reinforce the guidelines for linkage to public sewage treatment facilities, and to investigate the pollution of the public waters system. In addition, the pollution due to the exclusion of criteria for heavy metals and specified substance harmful to the quality of water has been covered in detail by “The Application of the Emission Allowance Standard ‘Na’, presented in the linkage guidelines. In Chapter 4, we analyzed the characteristics of the pollutants that pollute of the public water quality, and analyzed the status of the area and the treatment scale that are connected to the industrial wastewater treatment facilities as the main results of the study. In addition, we analyzed 17,325 of the 55,711 industrial facilities in the nationwide industrial pollution sources by 2015, and analyzed the industries that exceeded the criteria for containing heavy metals and emission limit ‘Na’. Heavy metal discharge status of the discharge facility is shown. Heavy metals and certain harmful substances entered into the public sewage treatment plant are concentrated in the sludge generated in the sewage treatment process or discharged to the river to cause contamination of the river sediment. In order to cope with these risks, the occurrence and treatment status of sewage sluge by treatment type is shown. This study has implications for establishing a tangible policy to examine and monitor of the cause sources of pollution. In order to improve the systematic limitation, this study proposed revision of guidelines for the linkage of industrial wastewater. In addition, this study proposed revision of guidelines for the linkage of industrial wastewater to improve institutional limitations, and summarized the regulation trends of developed countries on heavy metals and unregulated new substances. Based on this, it suggested the direction of the improvement of the domestic system so that it can be used as a pro-active policy tool to estimate and regulate new substances for the future regulation of water quality standards of discharged water pollution.

Wastewater from the textile industry: Review of the technologies for wastewater treatment and reuse

Ahsan Ali,Jamil Farrukh,Rashad Moeen Ali,Hussain Murid,Inayat Abrar,Akhter Parveen,Al-Muhtaseb Ala’a H.,Lin Kun-Yi Andrew,박영권 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.9

The textile industry is water intensive and discharges numerous coloring compounds into the water body that depend on the industry’s geographical location, the wet processes used for manufacturing, processing conditions, and the substrates involved. Textile wastewater contains chlorobenzenes, phthalates, heavy metals, azo dyes, and chlorophenols that have severe health issues, such as being allergenic, cytotoxic, genotoxic, mutagenic, and carcinogenic threats to living organisms. The differing concentrations of sulfates, chlorides, TOC, TDS, TSS, BOD, COD, high pH, and dye content characterize textile wastewater. To protect the environment and public health, a higher concentration of these items in textile wastewater is needed to treat the textile wastewater effluent before discharge. The conventional treatment methods are not able to fully remove the pollutants, such as physical treatments can only remove grease, oil, and TSS, whereas biological wastewater treatment (aerobic and anaerobic) can only decrease colors, COD, BOD, oil, and phenol with a higher accomplishment period and by-products. Therefore, it is necessary to develop effective ecofriendly, cost-effective, novel techniques, such as membrane technology, and a promising method with fewer by-products. The activated carbon method effectively removes heavy metals and dyes from the textile wastewater, and advanced oxidation processes (AOPs) are a recent development in textile wastewater treatment processes. Combining AOPs methods has been proven effective in removing pollutants when combined with biological and advanced physical processes. This paper reviews the textile manufacturing process, textile wastewater characteristics, textile wastewater’s impact on the environment and health, and the available textile wastewater treatment approach.

Phosphorus Removal from Urban Wastewater via Chemical and Combined Treatment against eutrophication of Receiving Environments

Nawel Nedjah,Nabila Laskri 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.7

This research work aims at highlighting the importance of wastewater treatment generally and removing phosphorus from these waters specifically, in order to preserve our environment. Reducing the rejected quantity of phosphorus, nutrient element, in the receiving environments, enables the restriction of the phenomenon of water streams eutrophication. This is the primary objective of our research. Both the chemical and biological treatments are recognized as effective for phosphorus removal from waste water. In our study, we worked on phosphorus removal from urban wastewater through three treatments types: chemical, biological, and a combined one. The findings of the chemical treatment demonstrated a good treatment efficiency of the organic matter: 95% of DCO and 88% of phosphorus; as per the biological treatment: 60% of DCO and 49% of phosphorus were found. A further treatment has been conducted through combining the first couple of treatments. This combination method seeks to find the optimal dose of the different conventional coagulants namely lime, ferric chloride and aluminum sulfate .The combined treatment resulted in a better phosphorus removal efficiency: 83% of phosphorus and 96% of DCO. The obtained results proved to be highly encouraging and incite the responsible / heads of STEP to adapt and apply this type of treatment which revealed to be an appropriate purification technique of wastewater.

고도 하수처리장의 전과정평가에 따른 환경성 및 경제성 평가

표세희 ( Se Hee Pyo ),김민정 ( Min Jeong Kim ),이승철 ( Seung Chul Lee ),유창규 ( Chang Kyoo Yoo ) 한국화학공학회 2014 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.52 No.4

최근 하수처리장의 질소 및 인 방류수 수질기준이 강화되고 슬러지의 해양투기가 금지됨에 따라 기존 표준활성슬러지공법의 고도처리공법으로의 증설 및 새로운 하수슬러지 처리공법에 대한 환경성, 경제성 평가의 필요성이 증가하고 있다. 이러한 고도처리 및 슬러지 처리공법은 운영 단계뿐만 아니라 건설, 폐기를 포함한 전과정에 걸쳐 환경 전반에 영향을 미치며 경제적 비용을 소모하므로, 본 연구에서는 건설에서부터 폐기까지의 전과정을 고려하여 고도처리공정 및 슬러지 처리 공법의 환경성, 경제성을 평가하고자 한다. 고도처리공법으로 Anaerobic/Anoxic/Oxic (A2O), Bamard Denitrification Phosphate (Bardenpho), Virginia Initiative Plant (VIP), Modified University of Cape Town (MUCT) 공법을, 슬러지 처리공법으로는 매립, 소각, 퇴비화를 선정하였다. 각 공법에 따른 환경성, 경제성 평가를 위하여 International organization for standardization (ISO)에서 제시하는 가이드라인을 따라 전과정평가를 수행하였으며, 전생애비용을 산정·비교하였다. 각 고도처리 공법에 대한 평가 결과, 환경영향 측면에서는 운영 단계에서의 생물학적 처리로 인한 온실가스 배출이, 경제성 측면에서는 운영 단계에서의 전력소모가 가장 많은 영향을 미치는 것으로 나타났다. 또한 가장 친환경적인 하수처리 및 슬러지 처리공법은 A2O 공법과 퇴비화로 환경에 가장 큰 영향을 미치는 CAS 공법과 매립에 비해 환경영향을 52% 줄일 수 있는 것으로 나타났다. 경제적인 측면에서는 가장 많은 비용을 소요하는 CAS 공법과 매립 적용 시에 비해 MUCT 공법과 퇴비화가 전생애비용을 62% 절약할 수 있음을 알 수 있었다. 본 연구를 통해 고도처리 공법으로의 증설 및 슬러지 처리에 대한 전과정을 고려하여 친환경적이며 경제적인 공법을 선정하기 위해 전 과정평가를 수행하고 전생애비용을 산출하여 각 공법을 비교 및 평가하였으며, 전과정평가의 환경성 및 경제성에 중요한 영향인자를 분석하였다. 따라서 본 연구의 방법론을 통하여 환경부하 및 경비 절감을 고려한 고도처리공법의 개보수 공정 및 슬러지 공정 선택이 가능할 것으로 예상된다. A lot of existing wastewater treatment plants (WWTPs) are rebuilt or retrofitted for advanced wastewater treatment processes to cope with reinforced effluent criteria of nitrogen and phosphorous. Moreover, how to treat the wasted sludge from WWTPs has been also issued since the discharge of the wasted sludge into ocean is impossible from 2011 due to the London Convention 97 protocol. These trend changes of WWTPs get a motivation to assess environmental and economic impacts from the construction stage to the waste stage in WWTPs. Therefore, this study focuses on evaluation of environmental and economic impacts of the advanced wastewater treatment processes and waste sludge treatment process by using life cycle assessment. Four advanced wastewater treatment processes of Anaerobic/Anoxic/ Oxic (A2O), 5 stages-Bamard Denitrification Phosphate (Bardenpho), Virginia Initiative Plant (VIP), and Modified University of Cape Town (MUCT) are chosen to compare the conventional activated sludge (CAS) and three waste sludge treatment methods of land fill, incineration, and composting are used. To evaluate environmental and economic impacts of each advanced wastewater treatment processes, life cycle assessment (LCA) and life cycle cost (LCC) are conducted based on International organization for standardization (ISO) guidelines. The results clearly represent that the A2O process with composting shows 52% reduction in the environmental impact than the CAS process with landfill. On the other hand, the MUCT process with composting is able to save 62% of the life cycle cost comparing with the CAS process with landfill. This result suggested the qualitative and quantitative criteria for evaluating eco-environmental and economic technologies of advanced treatment processes and also sludge treatment method, where their main influence factors on environmental and economic impacts are analyzed, respectively. The proposed method could be useful for selecting the most efficient and eco-friendly wastewater treatment process and sludge treatment method when retrofitting the existing WWTPs to advanced treatments.

하수처리장 연계처리를 위한 가축분뇨 최적 처리공정 선정에 관한 연구

김충곤,신현곤 유기성자원학회 2012 유기물자원화 Vol.20 No.3

As the result of reviewing the linked treatment of water quality for treating process at public livestock wastewater treatment facilities for fair selection of the proper linked process in case of linking sewage treatment plant for livestock wastewater, in case of wastewater processed by bio-reactor that is only biologically-treated, the load factor showed relatively high as 1.67%(base on design quality), 2.59%(base on operation quality) regarding COD and 3.69%(base on design quality), 7.67%(base on operation quality) regarding CODMn but it is judged that there is nearly no influence on the operation of sewage treatment plan. And, in case of oxidized flotation-treated water & biofiltlation-treated water that are the advanced wastewater treatment, the load factor is approximately 1% and there is concern about the installation of excessive facilities in case of installing the advanced wastewater treatment. So, in case of considering the economic efficiency & stable operation of sewage treatment plant S, it is judged to be desirable to link with wastewater processed by bio-reactor that is biologically-treated. 가축분뇨처리수의 하수처리장 연계 시 적정한 연계처리 공정 선정을 위해 가축분뇨공공처리시설의 처리공정별 연계처리수질을 검토한 결과 생물학적처리만 거친 생물반응조 처리수의 경우 연계부하율이 CODMn의 경우 1.67%(설계수질 기준), 2.59%(운영수질 기준), T-P의 경우 3.69%(설계수질 기준), 7.67%(운영수질 기준)로 다소 높게 나타났으나 하수처리장 운영에 미치는 영향은 거의 없을 것으로 판단된다. 또한, 고도처리공정인 산화부상분리 처리수 및 생물여과 처리수의 경우 연계부하율은 1% 내외로 고도처리설비 설치 시 과대 설비설치의 우려가 있다. 따라서 S하수처리장의 경제성 및 안정적인 운영을 고려할 경우 생물학적처리인 생물반응조를 거친 처리수를 연계하는 것이 바람직할 것으로 판단된다.

화학폐수 처리를 위한 전처리 공정으로서 전기응집의 경제성 분석

정종식,이재복 대한상하수도학회 2002 상하수도학회지 Vol.16 No.4

The objective of this study is to investigate the economic feasibility of electrocoagulation as pretreatment process for chemical wastewater treatment. The comparison of unit treatment cost by chemical coagulation and electrocoagulation process was carried out. The iron tube type electrode was used for electrocoagulation treatment of chemical wastewater. The removal efficiency of total phosphorus by electrocoagulation treatment was 95.7%. In the cost analysis for electrocoagulation process, operation cost of electrocoagulation process for chemical wastewater treatment was 661won/㎥. The unit treatment cost of chemical coagulation process for chemical wastewater treatment was 1,754won/㎥. And unit treatment cost of electrocoagulation process for chemical wastewater treatment was 1,166won/㎥. Electrocoagulation treatment as pretreatment process was more economic process from cost analysis comparing with traditional treatment of chemical coagulation.

옥수수속대를 이용한 세차장 폐수 흡착 처리

최희정 ( Hee-jeong Choi ) 한국수처리학회 2017 한국수처리학회지 Vol.25 No.3

The aim of this study was to investigate the car wash wastewater using corncob. Corncob was removed successfully the organic and anorgnic matters in the car wash wastewater at the following optimal parameters: 10 g/L of corncob, 150 rpm of mixing rate and from 6 to 7 of pH. The removal efficiency of turbidity, TDS (Total Dissolved Solid), and ABS (AlkylBenzene Sulfonates) were very high, more than 96%. However COD (Chemical Oxygen Demand), TN (Total Nitrogen) and TP (Total Phosphorus) was found to be 63-65%, 83-87% and 83-84%, respectively, and was relatively low removal efficiency compared turbidity, TDS and ABS. In particular, COD and TP exceeded the wastewater discharge standard and it is considered that post-treatment is necessary for stable treatment of car wash wastewater. Despite the low COD removal, treating car wash wastewater using corncob is very attractive. Because corncob can be treated with abandoned agricultural by-products to treat wastewater, and environmentally friendly because they are not using chemicals. Especially, turbidity, TDS and ABS have high removal efficiency, so that it is possible to reduce the processing cost of wastewater treatment if they are used as pre-treatment.