Nutrient removal in reverse osmosis concentrates using a biological aerated filter

IWA PUBLISHING 2015 WATER SCIENCE AND TECHNOLOGY -WATER SUPPLY- Vol.15 No.2

<P>The aim of this study is to employ a biological aerated filter (BAF) in the treatment of reverse osmosis (RO) concentrate received from reuse of treatment plant wastewater. Furthermore, the influence of chemical oxygen demand (COD)/N ratio on the nutrient removal was analyzed to find the detailed removal pathways of nutrients. The result was found to be high efficiency for biochemical oxygen demand removal (95.86%) compared to that of COD (88.95%) and suspended solids (81.12%). The total phosphorus (TP) (67.66%) and PO<SUB>4</SUB>-P (61.42%) removal efficiencies were relatively lower than that of total nitrogen (TN) (81.42%) and NO<SUB>3</SUB>-N (76.70%). This may be due to the fact that the biochemical oxygen demand (BOD)/TP ratio (8.01) was relatively low. Decreasing the COD/N ratio decreased TP and PO<SUB>4</SUB>-P removal efficiency. However, the removal efficiency of TN and NH<SUB>4</SUB>-N was increased from 47.60 to 64.54 and 54.17 to 73.72% with decreasing of COD/N ratio from 8.19 to 7.64, respectively. In addition, the denitrification rate and nitrification rate were increased from 211.8 to 301.0 mg/L d and 87.7 to 109.4 mg/L d, respectively, when COD/N ratios changed from 8.19 to 7.64. Therefore, in order to reuse the RO concentrate, the BAF process could effectively treat the RO concentrate.</P>

Analysis of the Factors Affecting Nutrients Removal in Hybrid Constructed Wetland Treating Stormwater Runoff

Sher Bahadur Gurung,Franz Kevin F. Geronimo,최혜선,홍정선,김이형 한국습지학회 2018 한국습지학회지 Vol.20 No.1

Nutrients generated from various land uses lead to eutrophication during the influx of water, and it is necessary to apply the LID techniques to reduce nutrients from nonpoint sources in order to mitigate the occurrence of the algal bloom. This study was carried out to derive the design factors of hybrid artificial wetland (HCW) to increase the removal efficiency of nutrients. HCW system was constructed in the year 2010 for the treatment of rainfall runoffs from parking lots and roads composed of 100% impervious floors in the Cheonan campus of Kongju University. The average nutrients removal efficiency of TN and TP was 74% and 72%, respectively. Both TN and TP removal efficiencies were higher than those of free surface wetlands and subsurface flow wetlands due to activated physical and ecological mechanisms. The critical design parameters for the efficient nutrients removal in the artificial wetlands were the ratio of the surface area to the catchment area (SA/CA), land use, the rainfall runoff, and the rainfall intensity. The optimal carbon to nitrogen (C/N) ratio was estimated at 5: 1 to 10.3: 1. The results of this study can be applied to the efficient design of hybrid artificial wetlands to treat nutrients in urban runoff with high efficiency.

혼합 산업폐수의 질소제거를 위한 외부 탄소원 투입과 물질수지: 실증실험

이몽학 ( Mong Hak Lee ),안조환 ( Jo Hwan Ahn ),이정훈 ( Jung Hun Lee ),배우근 ( Woo Keun Bae ),심호재 ( Ho Jae Shim ) 한국물환경학회 2012 한국물환경학회지 Vol.28 No.5

The feasibility of enhancing biological nutrient removal from an industrial wastewater was tested with food waste leachate and sugar liquid waste as external carbon sources. Long term influences of adding external carbon sources were investigated to see how the biological nutrient removal process worked in terms of the removal efficiency. The addition of the external carbons led to a significant improvement in the removal efficiency of nutrients: from 49% to approximately 76% for nitrogen and from 64% to around 80% for phosphorus. Approximately, 20% of the removal nitrogen was synthesized into biomass, while the remaining 80% was denitrified. Though the addition of external carbon sources improved nutrient removal, it also increased the waste sludge production substantially. The optimal observed BOD/TN ratio, based on nitrogen removal and sludge production, was around 4.0 in this study.

음식물 쓰레기, 분뇨 및 하수슬러지의 유기산 발효액을 이용한 하수고도처리

원찬희 ( Chan-hee Won ),김영일 ( Young-il Kim ),김원태 ( Won-tae Kim ) 한국환경기술학회 2006 한국환경기술학회지 Vol.7 No.2

우리 나라의 하수관거는 대부분 합류식으로 우수,지하수등의 다량 침투 및 건기시 오염물질의 침전, 분뇨의 별도 수거로 인해 하수처리장의 유입수는 설계 유입농도보다 낮으며, 쉽게 분해가능한 COD(RBCOD, Readily Biodegradable COD)의 함량의 불충분으로 생물학적 영양염류 제거(BNR)의 제한 요인으로 작용하고있다. 이러한 문제를 해결하기 위하여 기존 BNR공정의 혐기조, 무산소조, 호기조등의 각 반응조 체류시간을 최적화하거나, methanol, sodium acetate, acetic acid등과 같은 인공합성 유기물을 외부 탄소원으로 이용하기도 하지만 경제적인 면을 고려하여 일차 침전지나 농축조, 혐기성 소화조등을 발효조로 개량하거나 별도의 슬러지 발효조를 설치하여 여기서 생성된 분해가능한 BOD(SBOD, Soluble BOD), 휘발성 지방산(VFA, Volatile Fatty Acid)등의 쉽게 분해 가능한 유기물을 BNR공정의 혐기조 또는 무산소조에 탄소원으로 투입하는 전발효방법을 이용하는 사례가 늘고있다. 현재 음식물 쓰레기는 직매립 금지 이후 사료화, 퇴비화하고 있으나 이때 발생하는 침출수를 하수처리장에 병합처리 시 침출수의 유입으로 과도한 유기물 부하와, 유분에 의한 미생물 활성의 저하, 염분에 의한 미생물에의 독성(충격부하)등의 문제점이 있다. 따라서 본 연구에서는 음식물 쓰레기 및 분뇨 탈리액과 하수의 병합 처리시 위와같은 문제점의 해결과 BNR공법의 도입시에 외부탄소원의 활용방안으로 음식물자원화시설의 침출수, 분뇨 및 일차 슬러지 등을 발생량의 비로 혼합하여 유기산발효가 될 때 HRT, 혼합비등의 조건변화에 따른 휘발성 유기산의 생성과 BNR 공법에서 외부탄소원 공급시 고도처리 효율 향상을 검토하였다. Korean sewage pipes mostly consist of combined system of sewage. the influent of sewage treatment plant is less than designed influent concentration by the osmosis of a rainfall and a ground water, contaminant settlement and to extra take away of nightsoil. The insufficiency of Readily Biodegradable COD(RBCOD) affects restriction factors of Biological Nutrient Removal(BNR) process. To solve the problems that it is mentioned above, the hydrolic retention time(HRT) of anaerobic tank, anoxic tank, and oxic tank on existing BNR process is optimized, or synthetic substance of methanal, sodium acetate, and acetic acid is used as external carbon sources. But, considering the economic benefits, primary clarifier, sludge thickener, and sludge digester are changed into acid fermentation or extra sludge fermentaion tank is installed. The cases that readily biodegradable SBOD and VFA produced from acid fermentation tank is utilized as external carbon sources for the BNR process is increased. After the prohibition of food wastes reclamation, those are used for feed and manure. If we treat leachate of food and drink garbage with waste water, the problems of excessive the organic load, a drop of microorganism activity by the fatty substances, and damaged to the microorganism by the salinity are generated. In addition, there is a problem of the influent of Nonbiodegradable(NBD) material after the night-soil pretreatment. Accordingly, the purpose of this study was to solve the problems of food wastes and nightsoils leachate and sewage mixture treatment and to achieve high biological nutrient removal when VFA produced from acid fermentation of food wastes and nightsoils leachate and primary sludge be utilized as external carbon sources for the biological nutrient removal. Significant reduction and stabilization of the primary sludges can also be obtained from the acid fermentation. The objective of this study is to evaluate characteristics of acid fermentation of the food wastes and drink garbages and night-soils leachates and the primary sludge and to examine the influence of nutrient removal. An emphasis was placed upon the effect of HRT and mixing ratio of substances on acid fermentation.

Optimized cultivation of Ettlia sp. YC001 in eutrophic pond water for nutrient removal and biomass production

Oh, Hyung-Seok,Ahn, Chi-Yong,Srivastava, Ankita,Oh, Hee-Mock The Korean Society of Phycology 2018 ALGAE Vol.33 No.4

Ettlia sp. YC001, a highly settleable and productive microalga, was shown to be effective in removing nutrients and capturing suspended solids from eutrophic pond water. The optimum conditions for the Ettlia sp. YC001 cultivation were investigated using water from a landscape pond. The pond water was supplemented with different N : P ratios by weight, and the biomass production and nutrient removal compared in batch cultures. The maximum removal rate of N and P was with an N : P ratio of 16 : 1. Plus, the turbidity dropped to near zero within 4 days. Meanwhile, chemostat cultivation showed that the biomass productivity and nutrient removal rate increased when increasing the dilution rate, where a dilution rate of $0.9d^{-1}$ showed the highest N and P removal rate at $32.4mg\;L^{-1}\;d^{-1}$ and $1.83mg\;L^{-1}\;d^{-1}$, respectively, and highest biomass and lipid productivity at $0.432g\;L^{-1}\;d^{-1}$ and $67.8mg\;L^{-1}\;d^{-1}$, respectively. The turbidity was also reduced by 98% in the chemostat cultivation. Moreover, auto-flocculation and pH were closely connected to the turbidity removal. As a result, this study identified the optimal N : P ratio for small pond water treatment using an Ettlia sp. YC001, while also establishing the optimal conditions for nutrient removal, turbidity reduction, and biomass production.

Sequencing Batch Reactor (SBR) 에서 포기시간 변경에 따른 영향 (1) -영양염류 제거

정노성 ( No Sung Jeong ),박영식 ( Young Seek Park ),김동석 ( Dong Seog Kim ) 한국환경과학회 2011 한국환경과학회지 Vol.20 No.1

The effect of the variation of aeration time on the removal of organics, nitrogen and phosphorus using synthetic wastewater was investigated in sequencing batch reactors (SBRs) which included DNPAOs and DNGAOs. The cycling times in four SBRs were adjusted to 12 hours and then included different aerobic times as 1 hr, 2.5 hr, 4 hr and 5.5 hr, respectively. Four SBR systems have been operated and investigated for over 40 days. Average TOC removal efficiencies were about 71% in all SBRs. The NH4(+)-N removal efficiency was increased as the increase of aeration time. After changing aeration time, the total nitrogen removal efficiencies of SBRs were shown as 35 %, 85 %, 75 % and 65 %, respectively. Higher phosphorus release and uptake were occurred as the decrease of the aeration time. After all, the overall phosphorus removal efficiency decreased and the deterioration of phosphorus removal was occurred when aeration time was over 4 hr. Denitrification in aerobic conditions was observed, which showed the presence of DNPAOs and DNGAOs. In batch experiments, PAOs were shown as the most important microorganisms for the phosphorus removal in this experiment, and the role of DNGAOs was higher than that of DNAPOs for the nitrogen removal.

A Systematic Process Optimization Method for Advanced Environmental Process

Min Han Kim,Chang Kyoo Yoo 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

A systematic approach is proposed to find optimal operational conditions for nitrogen and phosphorus (N, P) removal in a biological nutrient removal processes, which is the dual optimization strategy through modeling, variable selection, design of experiments, and optimization using multiple response surface methodology. It is focused on determining the interactive effects between independent variables for N and P removal, which are selected through a new sensitivity analysis for considering the effluent quality index. After selecting key operational variables, multi-response surface model based on a new desirability function is used for the dual optimization of N and P removal. Because the proposed method is a multi-response model which is the suitable methods to optimize the operational conditions in a process, it can simultaneously optimize the biological process in the aspect of N and P removal efficiency. The proposed method is applied to a standard A2O process. The model-based optimization results in 78.0% and 80.0% removal efficiencies of N and P removal with the optimal process conditions, where are internal recycle flowrate of 3,850 g/m3, dissolved oxygen (DO) concentration of 1.0 mg/l, and wasted sludge rate of 27.5 g/m<SUP>3</SUP>, respectively. The dual optimization suggests to maximize simultaneous nitrification and denitrification (SND) in A2O system. This study confirms that the proposed dual optimization method is useful to systematically optimize the N and P removal in any biological nutrient removal process.

응집제의 첨가에 따른 Membrane bioreactor의 고도처리 효율 연구

박종부 ( Jong Bu Park ) 한국물환경학회 2011 한국물환경학회지 Vol.27 No.2

This study was performed to investigate the characteristics of nutrient removal of municipal wastewater in the submerged membrane bioreactor by addition of alum directly into aerobic tank. Membrane bioreactor consists of three reactors such as two intermittent anaerobic tanks and the aerobic tank with hollow fiber membrane. The removal efficiencies of CODCcr, BOD, SS, TN and TP on the membrane bioreactor were 94.0%, 99.1%, 99.9%, 66.9%, and 58.9%, respectively. In addition, The removal efficiencies of CODcr, BOD, SS, TN and TP on the membrane bioreactor with alum addition were 93.4%, 99.0%, 99.9%, 63.2%, and 96.8%, respectively. There was little difference between them on the nutrient removal efficiencies except phophorus removal. The estimated sludge production, specific denitrification rate, specific nitrification rate and phosphorus removal content on the membrane bioreactor were 1.76 kgTSS/d, 0.055 mgNO3-N/mgVSS·d, 0.031 mgNH4-N/mgVSS·d, and 0.095 kgP/d, respectively. And The estimated sludge production, specific denitrification rate, specific nitrification rate and phosphorus removal content on the membrane bioreactor with alum addition were 2.90 kgTSS/d, 0.049 mgNO3-N/mgVSS·d, 0.030 mgNH4-N/mgVSS·d, and 0.160 kgP/d, respectively. The alum content added was 1.7 molAl/molP on an average. The increasing ratio of tran-membrane pressure on the membrane bioreactor was 0.0056 kgf/cm2·compared to 0.0033 kgf/cm2·d on the membrane bioreactor with alum addition. There was a slightly reduction effect on membrane fouling by alum addition.

Treatment of real wastewater using co-culture of immobilized <i>Chlorella vulgaris</i> and suspended activated sludge

Mujtaba, Ghulam,Lee, Kisay Elsevier 2017 Water research Vol.120 No.-

<P><B>Abstract</B></P> <P>The use of algal-bacterial symbiotic association establishes a sustainable and cost-effective strategy in wastewater treatment. Using municipal wastewater, the removal performances of inorganic nutrients (nitrogen and phosphorus) and organic pollutants were investigated by the co-culture system having different inoculum ratios (R) of suspended activated sludge to alginate-immobilized microalgae <I>Chlorella vulgaris</I>. The co-culture reactors with lower R ratios obtained more removal of nitrogen than in pure culture of <I>C. vulgaris</I>. The reactor with R = 0.5 (sludge/microalgae) showed the highest performance representing 66% removal after 24 h and 95% removal after 84 h. Phosphorus was completely eliminated (100%) in the co-culture system with inoculum ratios of 0.5 and 1.0 after 24 h and in the pure <I>C. vulgaris</I> culture after 36 h. The COD level was greatly reduced in the activated sludge reactor, while, it was increasing in pure <I>C. vulgaris</I> culture after 24 h of incubation. However, COD was almost stabilized after 24 h in the reactors with high R ratios such as 2.0, 5.0, and 10 due to the higher concentration of activated sludge. The growth of <I>C. vulgaris</I> was promoted from 0.03 g/L/d to 0.05 g/L/d in the co-culture of low inoculum ratios such as R = 0.5, implying that there exist an optimum inoculum ratio in the co-culture system in order to achieve efficient removal of nutrients.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper highlights the use of co-culture system in municipal wastewater treatment. </LI> <LI> Removal of nutrients was significantly increased in properly inoculated co-culture system. </LI> <LI> Release of organic matter from <I>Chlorella</I> biomass decreased the COD removal performance. </LI> </UL> </P>

하폐수처리시설 2차 처리수의 잔존 유기물과 영양염류 제거를 위한 전해여과 영향 인자

최동혁,박종웅 한국도시환경학회 2019 한국도시환경학회지 Vol.19 No.4

This study elicited the operation factors of electrolytic oxidation-filtration to remove residual organics and nutrients in stabilized wastewater. The carbon fiber (CF) was more effective than stainless steel (SUS) as cathode in removing chemical oxygen demand (CODCr) at φ100 mm reactors. The CODCr removal with electrolytic oxidation-filtration (EOF), showed 71% removal, was higher than that with activated carbon filtration or electrolytic oxidation. The removal of total phosphorus (T-P) was higher with zeolite and that of CODCr was higher with activated carbon in both filtration and EOF at φ150 mm reactors. The reinforcement of electricity field was essential in reactor scaleup and the quantity of filtration media and the retention time of reactor were important factors. Additive concentric cylindrical SUS anode reinforced electricity field for 1.4 times in inner layer and 3.3 times in outer layer and increased CODCr removal in EOF both with zeolite and activated carbon. Under reinforced electricity field the increase of hydraulic retention time from 15min to 30min showed slight inCrease of removal efficiency, except with zeolite EOF, both in CODCr and nutrients. 본 연구는 기존 처리 폐수의 잔존 유기물과 영양염류를 제거하기 위하여 전해 여과의 운전조건을 도출하였다. 전극 재질을 비교한 결과 음극에 탄소섬유(CF) 전극을 이용하였을 때 스테인리스강(SUS) 전극보다 화학적 산소요구량(CODCr) 제거율이 높았다. 전해 활성탄 여과로 CODCr 제거율이 71%를 보여 활성탄 여과나 전해산화보다 효율적임을 알 수 있었다. 여과 또는 전해 여과 모두 총인은 제올라이트를 여재로 이용하였을 때, CODCr는 활성탄을 여재로 이용하였을 때 높은 제거율을 얻었다. 반응조 규모 확장 시 전기장 보강은 필수적이며 여과작용을 위한 여재의 양과 체류 시간이 중요한인자로 도출되었다. 동심 원통형 SUS 전극을 양극으로 추가하여 보강 전극을 기준으로 전기장 세기가 내측은 1.4배, 외측은 3.3배 강화됨으로써 전해 활성탄 여과와 잔해제올라이트여과 모두 CODCr 제거율이 향상되었다. 전극보강 조건에서체류 시간을 15 min에서 30 min으로 증가시킨 효과는 전해제올라이트여과 외에는 CODCr와 영양염류인 T-N, T-P 모두제거율의 향상이 미미하였다.