scholarly journals Kinetic and Prediction Modeling Studies of Organic Pollutants Removal from Municipal Wastewater using Moringa oleifera Biomass as a Coagulant

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2052 ◽  
Author(s):  
Bashir Adelodun ◽  
Matthew Segun Ogunshina ◽  
Fidelis Odedishemi Ajibade ◽  
Taofeeq Sholagberu Abdulkadir ◽  
Hashim Olalekan Bakare ◽  
...  
Keyword(s):  
Moringa Oleifera ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Low Cost ◽  
Oxygen Demand ◽  
Pollutant Removal ◽  
Multiple Observations ◽  
Organic Pollutants Removal ◽  
Seed Biomass ◽  
Pollutants Removal

This study investigated the potential of Moringa oleifera (MO) seed biomass as a coagulant for the removal of turbidity, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) of municipal wastewater. Triplicated laboratory experiments using MO coagulant added at varying treatment dosages of 50, 100, 150, 200 mg/L, and a control (0 mg/L) treatment were performed for a settling period of 250 min at room temperature. Kinetics and prediction variables of cumulative turbidity, BOD, and COD removal were estimated using simplified first order and modified Gompertz models. Results showed that the maximum removal of turbidity, BOD, and COD were 94.44%, 68.72%, and 57.61%, respectively, using an MO dose of 150 mg/L. Various kinetic parameters, such as rate constant (r), measured (REm) versus predicted (REp) cumulative removal, and specific pollutant removal rate (µm), were also maximum when an MO dose of 150 mg/L was added, the standard error being below 5%. The developed models were successfully validated over multiple observations. This study suggests low cost and sustainable removal of turbidity, BOD, and COD of municipal wastewater using MO seed biomass as a coagulant.

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 Laboratory-scale investigation on the role of microalgae towards a sustainable treatment of real municipal wastewater

2018 ◽  
Vol 78 (8) ◽  
pp. 1726-1732 ◽  
Author(s):  
S. Petrini ◽  
P. Foladori ◽  
G. Andreottola
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Batch Reactor ◽  
Low Cost ◽  
Oxygen Demand ◽  
Cost Effective ◽  
P Uptake ◽  
Ammonium Removal ◽  
N Assimilation

Abstract Engineered microalgal-bacteria consortia are an attractive solution towards a low-cost and sustainable wastewater treatment that does not rely on artificial mechanical aeration. In the research conducted for this study, a bench-scale photo-sequencing-batch reactor (PSBR) was operated without external aeration. A spontaneous consortium of microalgae and bacteria was developed in the PSBR at a concentration of 0.8–1.7 g TSS/L. The PSBR ensured removal efficiency of 85 ± 8% for chemical oxygen demand (COD) and 98 ± 2% for total Kjeldahl nitrogen (TKN). Nitrogen balance revealed that the main mechanisms for TKN removal was autotrophic nitrification, while N assimilation and denitrification accounted for 4% and 56%, respectively. The development of dense microalgae–bacteria bioflocs resulted in good settleability with average effluent concentration of 16 mgTSS/L. The ammonium removal rate was 2.9 mgN L−1 h−1, which corresponded to 2.4 mgN gTSS−1 h−1. Although this specific ammonium removal rate is similar to activated sludge, the volumetric rate is lower due to the limited total suspended solids (TSS) concentration (three times less than activated sludge). Therefore, the PSBR footprint appears less competitive than activated sludge. However, ammonium was completely removed without artificial aeration, resulting in a very cost-effective process. Only 50% of phosphorus was removed, suggesting that further research on P uptake is needed.

Novel biofilm reactor for denitrification of municipal wastewater

2018 ◽  
Vol 78 (7) ◽  
pp. 1566-1575 ◽  
Author(s):  
S. S. Rathnaweera ◽  
B. Rusten ◽  
K. Korczyk ◽  
B. Helland ◽  
E. Rismyhr
Keyword(s):  
Carbon Source ◽  
Municipal Wastewater ◽  
Low Cost ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Treated Wastewater ◽  
Removal Rates ◽  
Good Filter ◽  
Solids Removal

Abstract A pilot-scale CFIC® (continuous flow intermittent cleaning) reactor was run in anoxic conditions to study denitrification of wastewater. The CFIC process has already proven its capabilities for biological oxygen demand removal with a small footprint, less energy consumption and low cost. The present study focused on the applicability for denitrification. Both pre-denitrification (pre-DN) and post-denitrification (post-DN) were tested. A mixture of primary treated wastewater and nitrified wastewater was used for pre-DN and nitrified wastewater with ethanol as a carbon source was used for post-DN. The pre-DN process was carbon limited and removal rates of only 0.16 to 0.74 g NOx-N/m²-d were obtained. With post-DN and an external carbon source, 0.68 to 2.2 g NO3-Neq/m²-d removal rates were obtained. The carrier bed functioned as a good filter for both the larger particles coming with influent water and the bio-solids produced in the reactor. Total suspended solids removal in the reactor varied from 20% to 78% (average 45%) during post-DN testing period and 9% to 70% (average 29%) for pre-DN. The results showed that the forward flow washing improves both the DN function and filtration ability of the reactor.

scholarly journals Effects of selection and compiling strategy of substrates in column-type vertical-flow constructed wetlands on the treatment of synthetic landfill leachate containing bisphenol A

2021 ◽  
Author(s):  
Rajani Ghaju Shrestha ◽  
Daisuke Inoue ◽  
Michihiko Ike
Keyword(s):  
Activated Carbon ◽  
Bisphenol A ◽  
Landfill Leachate ◽  
Low Cost ◽  
Oxygen Demand ◽  
Ammonium Nitrogen ◽  
Pollutant Removal ◽  
Vertical Flow ◽  
Batch Mode ◽  
Synthetic Leachate

Abstract A constructed wetland (CW) is a low-cost, eco-friendly, easy-to-maintain, and widely applicable technology for treating various pollutants in the waste landfill leachate. This study determined the effects of the selection and compiling strategy of substrates used in CWs on the treatment performance of a synthetic leachate containing bisphenol A (BPA) as a representative recalcitrant pollutant. We operated five types of lab-scale vertical-flow CWs using only gravel (CW1), a sandwich of gravel with activated carbon (CW2) or brick crumbs (CW3), and two-stage hybrid CWs using gravel in one column and activated carbon (CW4) or brick crumbs (CW5) in another to treat synthetic leachate containing BPA in a 7-d sequential batch mode for 5 weeks. CWs using activated carbon (CW2 and CW4) effectively removed ammonium nitrogen (NH4-N) (99–100%), chemical oxygen demand (COD) (93–100%), and BPA (100%), indicating that the high adsorption capacity of activated carbon was the main mechanism involved in their removal. CW5 also exhibited higher pollutant removal efficiencies (NH4-N: 94–99%, COD: 89–98%, BPA: 89–100%) than single-column CWs (CW1 and CW3) (NH4-N: 76–100%, COD: 84–100%, BPA: 51–100%). This indicates the importance of the compiling strategy along with the selection of an appropriate substrate to improve the pollutant removal capability of CWs.

Assessment of the Effects of Ornamental Wetland Polyculture Combinations on Urban Sewage Treatment

2021 ◽  
Author(s):  
Min Wang ◽  
Yujue Zhou ◽  
Lin Xiang ◽  
Xiaoyang Ke ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Plant Diversity ◽  
Municipal Wastewater ◽  
Plant Biomass ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Wetland Plant ◽  
Urban Sewage ◽  
Thalia Dealbata ◽  
Cyperus Alternifolius

Abstract Previous studies have shown that wetland plants can treat wastewater in a cost-effective and sustainable way, however, the studies on the performance of ornamental wetland plant diversity in treating urban sewage were scarce. Therefore, this study was conducted to assess and select wetland polyculture combination that was effective in urban sewage treatment in subtropical areas. We formed five combinations out of six ornamental wetland plant species including Thalia dealbata, Cyperus alternifolius, Iris pseudacorus, Lythrum sastlicaria, Nymphaea tetragona, and Zantedeschia aethiopica. The growth state and removal effects of each plant combination were systematically measured and assessed. The results indicated all the combinations exhibited remarkable total nitrogen (TN), total phosphorus (TP), ammonium nitrogen (NH­4+-N), and chemical oxygen demand chromium (CODcr) removal rate of 70.75%-77.67%, 63.86%-73.71%, 69.73%-76.85%, and 57.28%-75.69%, respectively. Additionally, pH was reduced to 7.54-8.00 in the sewage. The purification effect reached the best during 30-36th day. The comprehensive assessment showed the mixture of Thalia dealbata + Cyperus alternifolius, closely followed by Thalia dealbata + Cyperus alternifolius+ Lythrum sastlicaria, was highly effective at extracting various pollutants, and both of them could be used as favorable combinations to convert eutrophication and purify municipal wastewater. Linear regression showed that TP, TP, NH­4+-N, and CODcr. were significantly related to plant biomass, indicating that plant biomass essential indicator for screening purification plants. Our study highlighted the importance of plant diversity in biological wastewater treatment, however the competition between plants was suggested to take into consideration in future studies.

Removal of pharmaceutical residue in municipal wastewater by DAF (dissolved air flotation)–MBR (membrane bioreactor) and ozone oxidation

2012 ◽  
Vol 66 (12) ◽  
pp. 2546-2555 ◽  
Author(s):  
Miyoung Choi ◽  
Dong Whan Choi ◽  
Jung Yeol Lee ◽  
Young Suk Kim ◽  
Bun Su Kim ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Ozone Oxidation ◽  
Dissolved Air Flotation ◽  
Treatment Processes ◽  
Pharmaceutical Residue ◽  
Dissolved Air

Growing attention is given to pharmaceutical residue in the water environment. It is known that pharmaceuticals are able to survive from a series of wastewater treatment processes. Concerns regarding pharmaceutical residues are attributed to the fact that they are being detected in water and sediment environment ubiquitously. Pharmaceutical treatment using a series of wastewater treatment processes of the DAF (dissolved air flotation)–MBR (membrane bioreactor)–ozone oxidation was conducted in the study. DAF, without addition of coagulant, could remove CODcr (chemical oxygen demand by Cr) up to over 70%, BOD 73%, SS 83%, T-N 55%, NH4+ 23%, and T-P 65% in influent of municipal wastewater. Average removal rates of water quality parameters by the DAF–MBR system were very high, e.g. CODcr 95.88%, BOD5 99.66%, CODmn (chemical oxygen demand by Mn) 93.63%, T-N 69.75%, NH4-N 98.46%, T-P 78.23%, and SS 99.51%, which satisfy effluent water quality standards. Despite the high removal rate of the wastewater treatment system, pharmaceuticals were eliminated to be about 50–99% by the MBR system, depending on specific pharmaceuticals. Ibuprofen was well removed by MBR system up to over 95%, while removal rate of bezafibrate ranged between 50 and 90%. With over 5 mg/l of ozone oxidation, most pharmaceuticals which survived the DAF–MBR process were removed completely or resulted in very low survival rate within the range of few micrograms per litre. However, some pharmaceuticals such as bezafibrate and naproxen tended to be resistant to ozone oxidation.

Research on Low Concentration Municipal Wastewater Removal Rate with Chemical-Biological Flocculation and Suspended Medium Process

2012 ◽  
Vol 599 ◽  
pp. 387-390
Author(s):  
Xing Yu Bian ◽  
Xing Sheng Kang ◽  
Yi Li ◽  
Yu Lin Sun ◽  
Min Kong ◽  
...  
Keyword(s):  
Municipal Wastewater ◽  
Removal Rate ◽  
Pilot Scale ◽  
Pollutant Removal ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Optimal Operating ◽  
Operational Parameter ◽  
Low Concentration ◽  
Scale Test

In this paper, chemical and biological flocculation and suspended medium process was applied to treat low concentration municipal wastewater in a pilot scale test in order to find the optimum operational parameter. The results showed that: system on pollutant removal mainly on chemical and biological flocculation reaction pool, Under the optimal operating condition, CODCr, TP and SS removal efficiencies reached 75.5％, 76％and 90.5％ respectively, and the CODCr, TP, SS concentrations of effluent meet the National Wastewater Integrated Discharge Standard. The optimum operating conditions according to the local actual situation, running for more than half a year, for the optimization of control parameters for the contrast obtained.

Effects of chemical oxygen demand (COD)/N ratios on pollutants removal in the subsurface wastewater infiltration systems with/without intermittent aeration

2016 ◽  
Vol 73 (11) ◽  
pp. 2662-2669 ◽  
Author(s):  
Siyu Song ◽  
Jing Pan ◽  
Shiwei Wu ◽  
Yijing Guo ◽  
Jingxiao Yu ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Oxygen Deficiency ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Intermittent Aeration ◽  
Oxidation Reduction ◽  
The Matrix ◽  
Pollutants Removal

The matrix oxidation reduction potential level, organic pollutants and nitrogen removal performances of eight subsurface wastewater infiltration systems (SWISs) (four with intermittent aeration, four without intermittent aeration) fed with influent chemical oxygen demand (COD)/N ratio of 3, 6, 12 and 18 were investigated. Nitrification of non-aerated SWISs was poor due to oxygen deficiency while higher COD/N ratios further led to lower COD and nitrogen removal rate. Intermittent aeration achieved almost complete nitrification, which successfully created aerobic conditions in the depth of 50 cm and did not change anoxic or anaerobic conditions in the depth of 80 and 110 cm. The sufficient carbon source in high COD/N ratio influent greatly promoted denitrification in SWISs with intermittent aeration. High average removal rates of COD (95.68%), ammonia nitrogen (NH4+-N) (99.32%) and total nitrogen (TN) (89.65%) were obtained with influent COD/N ratio of 12 in aerated SWISs. The results suggest that intermittent aeration was a reliable option to achieve high nitrogen removal in SWISs, especially with high COD/N ratio wastewater.

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 Optimization of active coagulant agent extraction method from Moringa Oleifera seeds for municipal wastewater treatment

2021 ◽  
Author(s):  
Raouf Bouchareb ◽  
Kerroum Derbal ◽  
Abderrezzak Benalia
Keyword(s):  
Wastewater Treatment ◽  
Extraction Method ◽  
Moringa Oleifera ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Extraction Process ◽  
Additional Treatment ◽  
Municipal Wastewater Treatment ◽  
Solvent Concentration ◽  
Coagulation Activity

Abstract An enhanced and different method for the active coagulant agent extraction from Moringa Oleifera seeds powder (MOSP) was established and compared to the conventional extraction method in distillate water. In the improved method, MOSP were extracted using sodium chloride as solvent at different concentrations to extract more coagulant agent from Moringa Oleifera and enhance coagulation activity. In this study, MOSP were initially processed and oil content was removed to minimize coagulant concentration usage (MOSP-EO). Moringa Oleifera seeds powder was characterized by both X-ray and FTIR analysis. Ultrasound treatment as well was considered as an additional treatment for MOSP-EO to investigate its effect on coagulant agent extraction process improvement. Coagulation/flocculation experiments were conducted to assess coagulant extraction performance realized through various conditions. The effect of coagulant dosage, solvent concentration and ultrasound exposition duration were investigated for a real effluent of municipal wastewater treatment. Among the three studied NaCl concentrations, 1.0 M was found to be the best solvent concentration for high turbidity removal of more than 97% using 140 mg/L of MOSP-EO compared to extraction in distillate water 88% using 170 mg/L of the same coagulant. NaCl 1.0 M demonstrated the best performance in biochemical oxygen demand (BOD5) removal as well, where more than 98% of municipal wastewater initial BOD5 was eliminated. Mixing MOSP-EO assisted with ultrasound waves at different treatment periods did decrease the active coagulant agent extraction and thus showed its inconvenient for Moringa Oleifera coagulation activity usage.

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