scholarly journals Removal of Heavy Metals and Nutrients from Municipal Wastewater using Salvinia molesta and Lemna gibba

2019 ◽  
Vol 9 (2) ◽  
Author(s):  
M.L.D.D. Abhayawardhana ◽  
N.J.G.J. Bandara ◽  
S.K.L.S. Rupasinge
Keyword(s):  
Heavy Metals ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Phosphate Removal ◽  
Lemna Gibba ◽  
Salvinia Molesta ◽  
Concentration Factors ◽  
Removal Efficiencies ◽  
Wastewater Samples

The present study was focused on the investigation of the abilities and efficiencies of Salvinia molesta and Lemna gibba to remove selected heavy metals (Cr, Cu, Fe, Ni and Pb) and excess nutrients from wastewater taken from the Moratuwa-Ratmalana municipal wastewater treatment plant. The wastewater samples were analysed for pH, Temperature, for N-Nitrates, N-Nitrites, ammonia Nitrogen, Phosphates, and selected heavy metals, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Total Kjeldhal Nitrogen. Then, the wastewater samples were treated with S. molesta and L. gibba separately for a period of 7 days and analysed for N-Nitrates, N-Nitrites, Ammonia Nitrogen, Phosphates and five selected heavy metals at 24 hour intervals. BOD, COD and Total Kjeldhal Nitrogen were analysed at 7 days intervals. The average Total Nitrogen removal efficiencies of S. molesta and L. gibba were 73.3% and 62.1% whereas the average Total Phosphate removal efficiencies of S. molesta and L. gibba were 72.6% and 77.2% respectively. The average Cr, Cu, Fe, Ni and Pb removal efficiencies of S. molesta were 81.6%, 69.8%, 65.2%, 66.3% and 74.8% respectively. The average Cr, Cu, Fe, Ni and Pb removal efficiencies shown by L. gibba were 86.9%, 69.7%, 73.1%, 61.8% and 85.7% respectively. The Bio Concentration factors of S. molesta for Cr, Cu, Fe, Pb and Ni were 823, 698, 652, 663 and 748 respectively and the Bio Concentration factors of S. molesta for Cr, Cu, Fe, Pb and Ni were 870, 698, 731, 618 and 857 respectively. According to the obtained results in the present study S. molesta and L. gibba can be considered as suitable candidates for the polishing of municipal wastewater.

scholarly journals Pollutant removal from municipal sewage by a microaerobic up-flow oxidation ditch coupled with micro-electrolysis

2021 ◽  
Vol 8 (12) ◽  
Author(s):  
Zhen-dong Zhao ◽  
Qiang Lin ◽  
Yang Zhou ◽  
Yu-hong Feng ◽  
Qi-mei Huang ◽  
...  
Keyword(s):  
Municipal Wastewater ◽  
Low Cost ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Influential Factors ◽  
Pollutant Removal ◽  
Municipal Sewage ◽  
Reflux Ratio ◽  
Oxidation Ditch ◽  
Important Challenge

The development of efficient and low-cost wastewater treatment processes remains an important challenge. A microaerobic up-flow oxidation ditch (UOD) with micro-electrolysis by waterfall aeration was designed for treating real municipal wastewater. The effects of influential factors such as up-flow rate, waterfall height, reflux ratio, number of stages and iron dosing on pollutant removal were fully investigated, and the optimum conditions were obtained. The elimination efficiencies of chemical oxygen demand (COD), ammonia nitrogen (NH 4 + -N), total nitrogen (TN) and total phosphorus (TP) reached up to 84.33 ± 2.48%, 99.91 ± 0.09%, 93.63 ± 0.60% and 89.27 ± 1.40%, respectively, while the effluent concentrations of COD, NH 4 + -N, TN and TP were 20.67 ± 2.85, 0.02 ± 0.02, 1.39 ± 0.09 and 0.27 ± 0.02 mg l −1 , respectively. Phosphorous removal was achieved by iron–carbon micro-electrolysis to form an insoluble ferric phosphate precipitate. The microbial community structure indicated that carbon and nitrogen were removed via multiple mechanisms, possibly including nitrification, partial nitrification, denitrification and anammox in the UOD.

scholarly journals The comparison of efficiency of Fenton and photo-Fenton treatment of stabilised landfill leachate / Porównanie efektywności oczyszczania odcieków z ustabilizowanego składowiska odpadów komunalnych w procesie Fentona i foto-Fentona

2015 ◽  
Vol 26 (3) ◽  
pp. 49-53 ◽  
Author(s):  
Anna Kwarciak-Kozłowska ◽  
Aleksandra Krzywicka
Keyword(s):  
Landfill Leachate ◽  
Fenton Reaction ◽  
Ferrous Sulphate ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Ammonia Removal ◽  
Mass Ratio ◽  
Leachate Treatment ◽  
Initial Ph ◽  
Removal Efficiencies

Abstract The goal of this article was to compare the efficiency of Fenton and photo-Fenton reaction used for stabilised landfill leachate treatment. The mass ratio of COD:H2O2 was fixed to 1:2 for every stages. The dose of reagents (ferrous sulphate/hydrogen peroxide) was different and ranged from 0.1 to 0.5. To determine the efficiency of treatment, the BOD (biochemical oxygen demand COD (chemical oxygen demand), TOC (total organic carbon) , ammonia nitrogen and BOD/COD ratio was measured. The experiment was carried out under the following conditions: temperature was 25ºC, the initial pH was adjusted to 3.0. Every processes were lasting 60 minutes. The most appropriate dose of reagents was 0.25 (Fe2+/H2O2). It was found that the application of UV contributed to increase of COD, TOC and ammonia removal efficiencies by an average of 14%.

Performance evaluation of subsurface wastewater infiltration system in treating domestic sewage

2012 ◽  
Vol 65 (4) ◽  
pp. 713-720 ◽  
Author(s):  
Ying-Hua Li ◽  
Hai-Bo Li ◽  
Jing Pan ◽  
Xin Wang ◽  
Tie-Heng Sun
Keyword(s):  
Operation Mode ◽  
Oxygen Demand ◽  
Surface Water Quality ◽  
Domestic Wastewater ◽  
Ammonia Nitrogen ◽  
The Mean ◽  
Removal Efficiencies ◽  
One Year ◽  
Physical And Chemical ◽  
Over Time

This study was to investigate domestic treatment efficiency of a subsurface wastewater infiltration (SWI) system over time. The performances of a young SWI system (in Shenyang University, China, fully operated for one year) and a mature SWI system (in Shenyang Normal University, China, fully operated for seven years) under the same operation mode were contrasted through field-scale experiments for one year. The performance assessment for these systems is based on physical and chemical parameters collected. The removal efficiencies within the young system were relatively high if compared with the mature one: for biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), ammonia nitrogen (NH3-N) and total phosphorus (TP) were 95.0, 89.1, 98.1, 87.6 and 98.4%, respectively. However, the removal efficiencies decreased over time. The mean removal efficiencies for the mature SWI system were as follows: BOD (89.6%), COD (87.2%), SS (82.6%), NH3-N (69.1%) and TP (74.4%). The results indicate that the mature SWI system successfully removed traditional pollutants such as BOD from domestic wastewater. However, the nutrient reduction efficiencies (including NH3-N and TP) decreased after seven years of operation of the mature SWI system. Meanwhile, the SWI system did not decrease the receiving surface water quality.

scholarly journals Increasing the Efficiency of Pollutants Removal from Municipal Wastewater Using Biological Filters

2019 ◽  
Vol 69 (12) ◽  
pp. 3553-3556
Author(s):  
Mariana Mincu ◽  
Maria Iuliana Marcus ◽  
Mihaela Andreea Mitiu ◽  
Natalia Simona Raischi
Keyword(s):  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Filling Material ◽  
Biological Filtration ◽  
Physico Chemical ◽  
Treatment Facilities ◽  
Pollutants Removal ◽  
Wastewater Samples ◽  
Chemical Water ◽  
Biological Filters

Biological filters are wastewater treatment systems that contain a granular filling material, which form an active biological film that contribute to the biooxidation of impurities from the wastewater. Recent research in the field aimed to improve the classical treatment facilities with aerobic fixed film by using inexpensive and easily accessible materials as filterable loading. Experiments have been carried out on biological filters loaded with volcanic tuff, with a diameter between 20-100 mm, supplied with municipal wastewater from primary settling. The biological filtration efficiency has been etablished throughout the continuous functioning of the experimental installation by physico-chemical water analysis. The analyzed indicators have been the ones stipulated by the legislation in force, namely: pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total suspended matter (TS), total nitrogen (TN), total phosphorus (TP), etc. The analysed wastewater samples have been average samples. The treatment efficiency have been calculated in various hypotheses, depending on the: installation capacity, hydraulic loading, organic loading.

scholarly journals Enhancement of COD, ammonia, phosphate and sulfide simultaneous removal by the anaerobic photosynthetic bacterium of Ectothiorhodospira magna in batch and sequencing batch culture

2018 ◽  
Vol 78 (9) ◽  
pp. 1852-1860 ◽  
Author(s):  
Xin Zhao ◽  
Xuejie Li ◽  
Nan Qi ◽  
Zhongtian Fu ◽  
Meng Chen ◽  
...  
Keyword(s):  
Batch Culture ◽  
Water Purification ◽  
Oxygen Demand ◽  
Photosynthetic Bacterium ◽  
Ammonia Nitrogen ◽  
Simultaneous Removal ◽  
Initial Ph ◽  
Photosynthetic Microorganism ◽  
Removal Efficiencies ◽  
First Time

AbstractAn anaerobic photosynthetic bacterium, with chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total phosphorus (TP) and sulfide (S2−) simultaneous removal ability, strain SU6, was isolated and identified as belonging to Ectothiorhodospira magna. Its removal efficiencies were simultaneously evaluated in batch culture and influenced in sequencing batch culture. The maximum COD, NH3-N, TP and S2− removal rates of 93.04%, 86.70%, 37.55% and 99.99% were obtained in batch culture with an initial pH 8.0 at 35 °C after 72 h. The simultaneous removal efficiency was enhanced in sequencing batch culture, and 789.27 mg/L COD, 68.91 mg/L NH3-N, 70.20 mg/L S2− and 5.26 mg/L TP were removed by the end of the last cycle within 24 h. This was the first time of reporting contaminants' simultaneous removal by a pure-cultured photosynthetic bacterium. The experimental results demonstrate that E. magna can efficiently serve as a good candidate in anaerobic wastewater contaminants' simultaneous removal, and maybe as another model anaerobic photosynthetic microorganism for water purification investigations.

Utilization of zeolite industrial wastewater for removal of copper and zinc from copper-brass pipe industrial wastewaterA paper submitted to the Journal of Environmental Engineering and Science.

2009 ◽  
Vol 36 (4) ◽  
pp. 709-719 ◽  
Author(s):  
Siranee Sreesai ◽  
Suthipong Sthiannopkao
Keyword(s):  
Heavy Metals ◽  
Industrial Wastewater ◽  
Ph Value ◽  
Oxygen Demand ◽  
Sorption Isotherms ◽  
Freundlich Equation ◽  
Metals Removal ◽  
Removal Efficiencies ◽  
The Relationship ◽  
Cu And Zn

Utilization of zeolite industrial wastewater as a sorbent and (or) precipitant to remove Cu and Zn from copper-brass pipe industrial wastewater was conducted. These wastewaters were sampled and values for pH, temperature, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), and heavy metals were determined. In addition, the sorption isotherms of Cu and Zn in copper-brass pipe industrial wastewater onto solids of zeolite industrial wastewater at various dilutions of copper-brass pipe industrial wastewater were explored. The relationship between Cu and Zn concentrations and their removal efficiencies under different conditions of wastewater pH, contact times, and ratios between copper-brass pipe industrial wastewater and zeolite industrial wastewater was examined. Zeolite industrial wastewater contained various carbonate compounds that contributed to high pH and TDS values, and low heavy metals contamination whereas copper-brass pipe industrial wastewater had a low pH value and was contaminated with heavy metals, especially Cu and Zn. Application of zeolite industrial wastewater significantly increased the pH of copper-brass pipe industrial wastewater and consequently removed Cu and Zn. The increase in pH of the wastewater mixture significantly enhanced the heavy metals removal. The Langmuir equation described sorption isotherms of Cu and Zn onto solids of zeolite industrial wastewater at neutral pH (6–7) while the Freundlich equation fitted well at pH > 12. The maximum Cu (97%–98%) and Zn (92%–96%) removal efficiencies occurred at the original pH 12.8 of zeolite industrial wastewater, at the ratio of copper-brass pipe industrial wastewater to zeolite industrial wastewater 3:1 (vol.:vol.) and at 30 min contact time.

scholarly journals Performance of Novel Contact Stabilization Activated Sludge System on Domestic Wastewater Treatment

2015 ◽  
Vol 19 (2) ◽  
pp. 7
Author(s):  
Andrés Felipe Torres Franco ◽  
Nancy Vásquez Sarria ◽  
Jenny Rodriguez Victoria
Keyword(s):  
Activated Sludge ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Growth Zone ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Activated Sludge System ◽  
Suspended Growth ◽  
Removal Efficiencies ◽  
Final Effluent

A pilot-scale study was conducted to evaluate a traditional contact stabilization activated sludge system (CSASC) and a modified CSAS (CSASM) treating domestic wastewater. The CSASC system was comprised of a contact reactor (CR), a stabilization reactor (SR) and a secondary settler (SS); the CSASM included a second CR, a second SS (CR2 and SS2), and a modified SR (SRM) divided into four zones: an attached-suspended growth zone which allowed the system to reach an average sludge retention time close to 36 d and favored the occurrence of nitrification; an anoxic zone for denitrification occurrence; an aerated suspended growth zone with a high presence of organic carbon; and an additional aerated suspended growth zone with a high ammonia concentrations environment. The CSASC’s removal efficiencies of chemical oxygen demand (COD) and total ammonia nitrogen (TAN) were respectively 94±4 % and 53±12%; whereas CSASM’s efficiencies were 88±7% for COD and 92±7% for TAN. Concentrations of TAN and NO3 --N in the CSASC’s final effluent were 14.3±5.2 and 5.0±2.9 mg×L-1; and 4.8±4.4 and 9.1±5.8 mg×L-1 in the CSASM’s final effluent. Results demonstrated that the proposed configuration obtained higher nitrogen removal efficiencies than traditional CSAS.</p>

Development of slow sponge sand filter (SpSF) as a post-treatment of UASB-DHS reactor effluent treating municipal wastewater

2016 ◽  
Vol 74 (1) ◽  
pp. 65-72 ◽  
Author(s):  
N. Maharjan ◽  
K. Kuroda ◽  
K. Dehama ◽  
M. Hatamoto ◽  
T. Yamaguchi
Keyword(s):  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Community Analysis ◽  
Total Coliform ◽  
Post Treatment ◽  
Pollutant Removal ◽  
Microbial Community Analysis ◽  
Anaerobic Sludge ◽  
Sand Filter ◽  
Removal Efficiencies

In this study, conventional slow sand filter (SSF) and modified slow sponge sand filter (SpSF) were investigated for the post-treatment of up-flow anaerobic sludge blanket (UASB)-down-flow hanging sponge (DHS) reactor effluent. The seasonal variation did not show significant differences in removal efficiencies of both filters. However in summer, both filters were able to achieve high total suspended solids and total biochemical oxygen demand removal averaging 97% and 99%, respectively. Contrary to organic removal, total nitrogen removal efficiency was satisfactory, showing increased removal efficiencies averaging 58% and 62% for SSF and SpSF in summer. On the other hand, average total coliform removal of SSF and SpSF was 4.2 logs and 4.4 logs and corresponding Escherichia coli removal was 4.0 logs and 4.1 logs, respectively. From our observation, it could be concluded that the relative performance of SpSF for nutrients and coliforms was better than SSF due to the effectiveness of sponge media over fine sands. Moreover, microbial community analysis revealed that the members of phylum Proteobacteria were predominant in the biofilms of both filters, which could have contributed to pollutant removal. Therefore, SpSF could be concluded to be a suitable post-treatment of UASB-DHS system in warmer conditions.

The Characteristics and Application of Water Quenched Slag Particles (WQSP) as Filter Media

2010 ◽  
Vol 156-157 ◽  
pp. 1247-1250
Author(s):  
Yan Feng ◽  
Yan Zhen Yu ◽  
Jian Wei Zhang ◽  
Tan Juan
Keyword(s):  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Total Porosity ◽  
Total Surface Area ◽  
Ammonia Nitrogen ◽  
Mass Ratio ◽  
Filter Media ◽  
N Removal ◽  
The Media ◽  
Heavy Metal Elements

Novel filter media-water quenched slag particles (WQSP) were prepared using waste material- Water quenched slag, clay and pore-forming material with a mass ratio of 3:2:1. Compared with haydite, WQSP had higher total porosity, larger total surface area and lower bulk and apparent density. Tests of heavy metal elements in lixivium proved that SGSP were safe for wastewater treatment. In order to ascertain the application of WQSP ，WQSP and haydite were applied as the media of biological aerated filters (BAF) to treat municipal wastewater in two lab scale upflow BAFs. The results showed that WQSP reactor brought a relative superiority to haydite reactor in terms of chemical oxygen demand (CODcr) and ammonia nitrogen (NH3-N) removal at the conditions of water temperature ranging from 200C to 260C and DO ≥4.00 mg·L-1. Therefore, WQSP application, as a novel process of treating wastes with wastes, provided a promising way in water quenched slag utilization.

scholarly journals Performance of air-cathode stacked microbial fuel cells systems for wastewater treatment and electricity production

2017 ◽  
Vol 76 (3) ◽  
pp. 683-693 ◽  
Author(s):  
Edson Baltazar Estrada-Arriaga ◽  
Yvonne Guillen-Alonso ◽  
Cornelio Morales-Morales ◽  
Liliana García-Sánchez ◽  
Erick Obed Bahena-Bahena ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Microbial Fuel Cells ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Maximum Power ◽  
Electricity Production ◽  
Municipal Wastewater Treatment ◽  
Air Cathode ◽  
Removal Efficiencies ◽  
Power Densities

Two different air-cathode stacked microbial fuel cell (MFC) configurations were evaluated under continuous flow during the treatment of municipal wastewater and electricity production at a hydraulic retention time (HRT) of 3, 1, and 0.5 d. Stacked MFC 1 was formed by 20 individual air-cathode MFC units. The second stacked MFC (stacked MFC 2) consisted of 40 air-cathode MFC units placed in a shared reactor. The maximum voltages produced at closed circuit (1,000 Ω) were 170 mV for stacked MFC 1 and 94 mV for stacked MFC 2. Different power densities in each MFC unit were obtained due to a potential drop phenomenon and to a change in chemical oxygen demand (COD) concentrations inside reactors. The maximum power densities from individual MFC units were up to 1,107 mW/m2 for stacked MFC 1 and up to 472 mW/m2 for stacked MFC 2. The maximum power densities in stacked MFC 1 and MFC 2 connected in series were 79 mW/m2 and 4 mW/m2, respectively. Electricity generation and COD removal efficiencies were reduced when the HRT was decreased. High removal efficiencies of 84% of COD, 47% of total nitrogen, and 30% of total phosphorus were obtained during municipal wastewater treatment.

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