Browsing by Author "Daverey, Achlesh"

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Ambient temperature SNAD process treating anaerobic digester liquor of swine wastewater
(2013-08-01)
Daverey, Achlesh
;
Hung, Nien-Tzu
;
Dutta, Kasturi
;
Lin, Jih-Gaw
;
環境工程研究所
In present study, effluent from anaerobic digestion of swine wastewater was treated by the simultaneous partial nitrification, anaerobic ammonium oxidation and denitrification (SNAD) process using a lab scale 5 L sequencing batch reactor (SBR) under ambient temperature. The fluctuation of anaerobic digester liquor quality (COD, 387 +/- 145 mg/L; TKN, 662 +/- 190 mg/L; NH4+-N, 519 +/- 134 mg/L) and temperature created difficulties to develop a stable SNAD process in the SBR (days 1-285). Fed batch feeding strategy was adopted to have a stable condition in the reactor and overcome the negative effects of organic nitrogen. The average total nitrogen, NH4+-N and COD removal efficiencies in the SBR under steady state conditions (days 485-523) were 80%, 96% and 76%, respectively. The results showed that presence of organic nitrogen, mode of feeding and reactor temperature affects the SNAD process. (C) 2013 Elsevier Ltd. All rights reserved.
Effect of zinc on anammox activity and performance of simultaneous partial nitrification, anammox and denitrification (SNAD) process
(2014-08-01)
Daverey, Achlesh
;
Chen, Yi-Chian
;
Sung, Shihwu
;
Lin, Jih-Gaw
;
環境工程研究所
In the present study, short-term effects of zinc on anammox activities and long-term effect of zinc on the performance of simultaneous partial nitrification, anammox and denitrification (SNAD) process were evaluated. The anammox activity decreased with increasing zinc concentration and exposure time in short-term tests. The IC50 value of zinc was found to be 6.9 mg/L. However, the presence of zinc (<10 mg/L) in wastewater stimulated the microbial activities and nitrogen removal performance of SNAD process in sequencing batch biofilm reactor (SBBR). At first, inhibition of SNAD process was observed when influent zinc concentration increased to 20 mg/L. The system recovered immediately, suggesting the acclimatization of microbial communities of SNAD process. The results showed that SBBR was well acclimatized under high zinc concentration (50-100 mg/L) achieving 98% NH4+-N, 96% TN and 87% COD removal efficiencies. (C) 2014 Elsevier Ltd. All rights reserved.
Evolution retrospective for alternative fuels: First to fourth generation
(2014-09-01)
Dutta, Kasturi
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Daverey, Achlesh
;
Lin, Jih-Gaw
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環境工程研究所
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Institute of Environmental Engineering
The ever increasing worldwide demand for liquid and gaseous fuels along with overwhelming environmental concerns for greenhouse gas emissions have driven scientists and technologists to consider different alternative energy sources. In past decades, several biomass sources have been identified with increasing potential to be used as new alternative sources of energy - the "Biofuels". The evolution of biofuels is classified into four different generations. In this article an overview of the systematic evolution of different biofuel generations with their advantages and disadvantages has been presented. The advancements in technology, reduction in greenhouse gas emission and assessment of commercial production cost of each generation of biofuel have also been highlighted. Finally this review provides an outlook for a better future generation biofuel. (C) 2014 Elsevier Ltd. All rights reserved.
Nitrogen removal from opto-electronic wastewater using the simultaneous partial nitrification, anaerobic ammonium oxidation and denitrification (SNAD) process in sequencing batch reactor
(2012-06-01)
Daverey, Achlesh
;
Su, Sin-Han
;
Huang, Yu-Tzu
;
Lin, Jih-Gaw
;
環境工程研究所
Simultaneous partial nitrification, anaerobic ammonium oxidation and denitrification (SNAD) system was applied to treat the opto-electronic industrial wastewater in a 2.5 L sequencing batch reactor. The characteristics of wastewater were low C/N ratio (similar to 0.2) with 100 mg-COD/L and 567 mgNH(4)(+)-N/L. The experiment was carried out over 8 months in six different stages, where nitrogen loading rate was gradually increased from 16 g-N/m(3) d in stage I to 230 g-N/m(3) d in stage VI. The COD and nitrogen removal rates by the SNAD system reached to 28 g COD/m(3) d and 197 g NH4+-N/m(3) d, respectively in stage VI. These results showed that the SNAD system is suitable to treat wastewater containing high nitrogen pollutants with low COD level. Presence of ammonium oxidizing bacteria and anammox bacteria were confirmed by polymerase chain reaction (PCR). PCR results also indicated that Candidatus Kuenenia stuttgartiensis may be one of the dominant species in the reactor. (C) 2011 Elsevier Ltd. All rights reserved.
Optimization of photo-Fenton process parameters on carbofuran degradation using central composite design
(2012)
Lu, Li A.
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Ma, Ying S.
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Daverey, Achlesh
;
Lin, Jih G.
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環境工程研究所
Carbofuran, one of the most toxic and biorefractory carbamate compounds, is widely used in insecticides in Taiwan (9-18% of total insecticides production per year). In the present study, a central composite design experiment was used to study the effect of photo-Fenton treatment on carbofuran solution and to optimize the process variables such as carbofuran concentration (1-100 mg L-1), H2O2 dosage rate (0.25-6 mg L-1 min(-1)) and Fe3+ dosage (1-50 mg L-1), which influenced the efficiency of carbofuran degradation and mineralization. The results indicated that all the variables investigated in this study had significant roles in the degradation and mineralization of carbofuran in solution. The carbofuran degradation and mineralization efficiencies were increased with increase in H2O2 dosage rate and Fe3+ dosage, and with decrease in carbofuran concentration. Furthermore, optimum values of both H2O2 dosage rate and Fe3+ dosage were found to shift to higher values as carbofuran concentration increased. Based on the model obtained in this study, optimum H2O2 dosage rate and Fe3+ dosage were found to be 4 mg L-1 min(-1) and 20 mg L-1, respectively, for 51 mg L-1 of carbofuran concentration. Under these conditions, carbofuran was completely removed within 30 min and coupled with 78% mineralization at the end of experiment.
Partial nitrification and anammox process: A method for high strength optoelectronic industrial wastewater treatment
(2013-06-01)
Daverey, Achlesh
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Su, Sin-Han
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Huang, Yu-Tzu
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Chen, Shiou-Shiou
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Sung, Shihwu
Completely autotrophic nitrogen removal over nitrite (CANON) process was employed in an 18 L sequencing batch reactor (SBR) for treatment of optoelectronic industrial wastewater containing high strength ammonium nitrogen (3712 +/- 120 mg NH4+ - N L-1). About 89% of total nitrogen and 98% of NH4+ - N removal efficiencies were observed at the loading rate of 909 g N m(-3) d(-1) and the HRT of 4 d. A profound variation in the performance of CANON process was experienced at high DO exposure (above 1 mg L-1) and high nitrite concentration (above 100 mg L-1). Inhibition due to high DO exposure was found to be reversible phenomenon whereas the synergistic inhibition of nitrite, free ammonia and free nitrous acid was irreversible. The fluctuation of reactor temperature between 17 and 37 degrees C did not affect the performance of CANON system. The CANON process was stably controlled at high nitrogen loading rate for more than one month. The co-existence of aerobic and anaerobic ammonium oxidizing bacteria in the reactor was detected by The PCR analysis. About 5 fold increase in amount of anammox bacteria over a period of 258 days was confirmed from the results of qPCR on day 487. (C) 2013 Elsevier Ltd. All rights reserved.
Start-up of simultaneous partial nitrification, anammox and denitrification (SNAD) process in sequencing batch biofilm reactor using novel biomass carriers
(2015-08-01)
Daverey, Achlesh
;
Chen, Yi-Chian
;
Dutta, Kasturi
;
Huang, Yu-Tzu
;
Lin, Jih-Gaw
Simultaneous partial nitrification, anammox and denitrification (SNAD) process was started-up in a 2.5 L sequencing batch biofilm reactor (SBBR) using novel biomass carriers. The SNAD process took only 51 d for start-up at nitrogen loading rate (NLR) and organic loading rate (OLR) of 120 and 60 g/m(3)-d, respectively. Long-term stable operation of SNAD process was observed at NLR and OLR of 360 and 180 g/m(3)-d with average total nitrogen and COD removal efficiencies of >88% and >90%, respectively. The values of conversion ratio Y(NO2-+NO3-)/NH4+ remained below 0.11 after the start-up period, which further confirmed the long-term stability of SNAD process. Results of polymerase chain reaction (PCR), qualitative PCR, and scanning electron microscopic (SEM) analysis of sludge samples confirmed the co-existence and enrichment of AOB, anammox bacteria and denitrifying bacteria in the reactor and biofilm formation on to the carriers. (C) 2015 Elsevier Ltd. All rights reserved.
Statistical analysis to evaluate the effects of temperature and pH on anammox activity
(2015-08-01)
Daverey, Achlesh
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Chei, Pang Chang
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Dutta, Kasturi
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Lin, Jih-Gaw
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環境工程研究所
Anaerobic ammonium oxidation (anammox) is the most efficient process of nitrogen removal from wastewater. A central composite design was employed to study the individual and interactive effects of temperature and pH on the activity of anammox bacteria. A total of 13 experiments including 5 center point replicates with specific anammox activity as a response were carried out. The maximum specific anammox activity (0.0286 +/- 0.0003 g N-2-N g VSS-1 d(-1)) was observed at temperature and pH of 43 degrees C and 7.5, respectively. The results of estimated regression coefficients for specific anammox activity suggested that both temperature and pH positively affects the specific anammox activity of bacteria. The effect of pH was found to be more significant than temperature as evident from the P value (P < 0.05). Further, contour plot revealed that the interaction between pH and temperature is also significant. Regression model equation was developed to predict the specific anammox activity at particular pH and temperature. The regression model was validated by carrying out experiment at lower temperatures (25, 20 and 15 degrees C) with varying pH, which revealed that an appropriate anammox activity could be maintained at lower temperature by changing pH. The study suggested that higher pH should be maintained in wastewater treatment plant to achieve the high anammox activity at lower temperatures. (C) 2015 Elsevier Ltd. All rights reserved.
Treatment of semiconductor wastewater using single-stage partial nitrification and anammox in a pilot-scale reactor
(2016-06)
Liang, Ying-Chang
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Daverey, Achlesh
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Huang, Yu-Tzu
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Sung, Shihwu
;
Lin, Jih-Gaw
Start-up of pilot scale reactor to treat real semiconductor wastewater is reported in this study. Semiconductor industrial wastewater stream was characterized as highly alkaline (pH 10) and contained high concentration of H2O2 of 311 +/- 505 mg/L, ammonium nitrogen of 318 +/- 122 NH4+-N mg/L and negligible COD of <10 mg/L. H2O2 was removed by adding enzyme "REYONET F-35" and H2SO4. Before the H2O2-free wastewater is fed to the biological reactor, the pH is adjusted to similar to 7.0. Completely autotrophic nitrogen removal over nitrite (CANON) process was cultivated in a 1.0 m(3) pilot-scale sequencing batch reactor by using enzyme pretreated semiconductor wastewater without temperature control. The nitrogen loading rate was increased step-wise from 94 to 665 g NH4+-N/m(3) d. The average NH4+-N and total nitrogen removal efficiencies were 85.5 and 75.7%, respectively at NLR of 665 g NH4+-N/m(3) d and HRT of 4 d. The pilot reactor was successfully started up and operated for more than 550 d. The CANON was evidenced by the ratio of the effluent nitrite and nitrate to ammonium ratio (eta) of 0.076 during the steady state operation period. PCR results also confirmed the presence of AOB (aerobic ammonia oxidizing bacteria) and anammox (anaerobic ammonia oxidizing) bacteria in the reactor. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.