Wyniki wyszukiwania - BazTech

1

Total phosphorus and total Kjeldahl nitrogen removal using an aerobic granular sludge process. Case studies ANN and RSM modeling

Sanchez-Sanchez Celina, Flores-Gomez Jean, Moeller-Chávez Gabriela, Morales-Rivera Juan

Environment Protection Engineering

|

2024

|

Vol. 50, nr 1

123--137

EN

Removing nutrients from wastewater is essential because high concentrations in aquatic systems lead to severe eutrophication problems, the most common impairment of surface waters such as lakes and oceans. Total phosphorus (TP) and total Kjeldahl nitrogen (TKN) were removed from mixed wastewater using an aerobic granular sludge process in a sequencing batch reactor (AGS-SBR). An artificial neural network (ANN) and response surface methodology (RSM) were applied to evaluate the main parameters of the process. For TKN removal, only cycle time (CT) (0.0475) was a significant variable, achieving removal efficiencies of up to 81%. In TP case removal, two parameters, VER and AR, were substantial for this process, completing elimination efficiencies of around 40%. On comparing the models with statistical indices, ANN coupled with the moth-flame optimization algorithm (ANN-MFO) demonstrated higher performance with an adjusted R2 (0.9866) for the case of TP removal and (0.9519) for TKN removal.

2

Nitrogen removal from ammonium-rich pharmaceutical wastewater. A comparison between sequencing batch reactor (SBR) and sequencing batch biofilm reactor (SBBR)

Hajsardar M., Borghei S. M., Hassani A. H., Takdastan A.

Environment Protection Engineering

|

2018

|

Vol. 44, nr 3

95--115

EN

Biological nitrogen removal from industrial wastewater (pharmaceutical synthetic wastewater) was studied. Sequencing batch reactor (SBR) and sequencing batch biofilm reactor (SBBR) were utilized to treat ammonium-rich wastewater. No external carbon source was added to the reactors. At nitrogen loading rate (NLR) of 2.5 kg N/(m3·day), the efficiency of ammonium removal from synthetic wastewater in SBR was 86.9%. SBBR ammonium removal efficiency under fixed dissolved oxygen (DO) concentration of 0.3 mg O2/dm3 was 98.4%. Specific nitrification rate (SNR) and specific denitrification rate (SDNR) in SBR were 9.24 mg NH4 +-N/(g MLVSS·h) and 18.56 mg NO3 – -N/(g MLVSS·h), respectively. Nitrite accumulation rate (NAR) showed high correlation with DO decrement (R2 = 0.983), NAR and simultaneous nitrification and denitrification (SND) had high correlation, too (R² = 0.976). SND efficiency in SBBR reached 94.1% while ammonium oxidizing bacteria (AOB) were dominant and NAR in SBBR process at the DO level of 0.3 mg O2/dm3 was 90.3%.

3

Enrichment of PAO and DPAO responsible for phosphorus removal at low temperature

Haiming Z., Xiwu L., Abualhail S., Jing S., Qian G.

Environment Protection Engineering

|

2014

|

Vol. 40, nr 1

67--83

EN

A new strategy of enrichment of polyphosphate accumulating organisms (PAO) and denitrifying polyphosphate accumulating organisms (DPAO) at low temperature ranging from 8 °C to 11 °C was demonstrated through two lab-scale reactors operated in sequential anaerobic-aerobic (AO) or anaerobic-anoxic (AA) conditions. It was found that the AO reactor is able to achieve a good phosphorus removal performance after 40 days of operation, while a similar stable phosphorus removal can be obtained in the AA reactor after 80 days. This result suggests that the enrichment of PAO was easier than that of DP AO at low temperature. Through switching batch tests, when DPAO is exposed to aerobic conditions, it can immediately exhibit a good phosphorus removal similar to that under anoxic conditions, while PAO can only present poor phosphorus removal when exposed to anoxic conditions, suggesting that two different types of Accumulibacter were enriched both in AA and AO reactors. Microbial analysis with fluorescence in situ hybridization (FISH) and DAPI (4',6-diamidino-2 -phenylindole) staining revealed that Accumulibacter was dominant both in the two reactors, accounting for 61.6% and 79.3% of all bacteria in AA and AO reactors, respectively. Although the different amount of Accumulibacter was enriched in the two reactors, the similar microbial morphologies were observed by using scanning electron micrograph (SEM), both presenting long-rod morphology. This kind of Accumulibacter may display affinities for sodium acetate used as the carbon sources here. This strategy proposed in this study was shown to be effective in achieving a very high enrichment of Accumulibacter at low temperature by linking chemical analysis with microbial observation.

4

Wykorzystanie lakazy natywnej i immobilizowanej do usuwania p-anizydyny

Bryjak J., Matysik M., Krawczyk W.

Inżynieria i Aparatura Chemiczna

|

2013

|

Nr 6

523--524

PL

Wykorzystanie lakazy do utleniania związków fenolowych w wodach odpadowych uznawane jest za metodę perspektywiczną. Z tego powodu w badaniach zastosowano enzym natywny i immobilizowany do utleniania p-anizydyny, co prowadzi do powstania rodników i ich spontanicznej polimeryzacji. Ułatwia to późniejszą sedymentację lub filtrację uzyskanych produktów. Wykazano, że lakaza jest stabilizowana w obecności 10% 2-propanoic Dodatkowo w tym układzie nie dochodzi do wytrącania produktów na powierzchni wyselekcjonowanego nośnika

EN

Applications of laccase in specialty wastewater treatment were recently increasingly reported. In this work native and immobilized laccase was used for p-anisidine oxidation to form polymerized phenolic compounds that can be easily removed by sedimentation or filtration. It was shown that 10% 2-propanol in the reaction mixture stabilized both forms of laccase, Additionally, it prevented strong sorption of oxidized products on the surface of selected enzymecarrier preparation.

5

Microbial degradation of phenol by activated sludge in a batch reactor

Duan Z.

Environment Protection Engineering

|

2011

|

Vol. 37, nr 2

53-63

EN

Biodegradation of phenol in a batch reactor was investigated using activated sludge. The sludge was able to degrade phenol of initial concentrations up to 1.500 mg/dm 3. The optimum temperature and pH for the reaction were determined in extensive tests. The optimum pH was around 6, whereas the temperature showed no significant impact on the biodegradation rates over the investigated conditions. This activated sludge degraded phenol at the maximum rate of 0.048 g phenol/(g VSSźh) at pH 6 and 30 °C, whereas inhibitory effects existed at concentrations higher than 100 mg/dm 3. The Haldane kinetic model was used to elucidate the kinetics of phenol degradation in an activated sludge. The kinetic parameters were estimated to be q max = 0.4695 g phenol/(g VSSźh), K 1 = 28.4860 mg/dm 3, and K s = 603.9869 mg/dm 3, with the correlation coefficient (R 2) of 0.9599. The high q max value for phenol biodegradation shows that the activated sludge exhibited high resistance to phenol.

6

Kinetic studies of decolonisation of concentrates from nanofiltration treatment of real textile effluents in anaerobic/aerobic sequencing batch reactors

Klepacz-Smółka A., Paździor K., Ledakowicz S., Sójka-Ledakowicz J., Mrozińska Z., Żyłła R.

Environment Protection Engineering

|

2009

|

Vol. 35, nr 3

145-155

EN

The aim of the research was to investigate the degradation of real textile wastewater concentrate obtained in the nanofiltration processes. An anaerobic/aerobic sequencing batch reactor system working in a 24-h cycle was applied. The anaerobic phase aimed at the reduction of Reactive Red 120 molecules was followed by the aerobic oxidation of aromatic amine (orthanilic acid) released from azo dye. Two different successive decolourisation periods were observed in the anaerobic bioreactor for two tested concentrates of textile wastewater. A first-order reaction model was used to describe the decolourisation process. Furthermore, the relation between COD reduction and the concentrate decolourisation was observed. The aromatic amine was completely degraded in the aerobic stage only in the case of two-fold-concentrated textile wastewater.