scholarly journals Depuration Performance of Aerated Tanks Simulating Lagoons to Treat Olive Oil Mill Wastewater under Different Airflow Rates, and Concentrations of Polyphenols and Nitrogen

Environments ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 70
Author(s):  
Serafina Andiloro ◽  
Giuseppe Bombino ◽  
Pietro Denisi ◽  
Adele Folino ◽  
Demetrio Antonio Zema ◽  
...  

The uncontrolled disposal of olive oil mill wastewater (OMW) is hazardous for the health of water and soil, since this wastewater shows low pH and high contents of organic matter and polyphenols (PP). Lagooning is one of the most common treatment systems for agro-industrial wastewater (such as OMW), due to its low cost and easy management. Aeration allows reducing the low depuration time, which is a constraint for this system. Despite this potential feasibility, literature about OMW lagooning is not abundant. Moreover, the effects of the aeration rates, concentration of polyphenols and nitrogen shortage on depuration performance of lagoons treating OMW have not been properly explored. This study analyzes the removal rates of COD and PP, and variations of pH in OMW treated in aerated tanks at the laboratory scale simulating lagooning systems. Compared to the non-aerated tanks, aeration of OMW increased the removal rates from 61% to 90% (for COD) and from 52% to 64% (for PP). Permanent aeration was more advisable compared to intermittent flow rates. Increasing concentrations of PP noticeably reduced the COD removal rates, which were halved at a 4-fold PP concentration. In contrast, the PP removal rate was constant at every concentration experimented. Compared to the COD:N value suggested by literature for aerobic processes (100:5), a shortage in nitrogen availability reduced both COD (by about 20–25%) and PP removal rates (by 25%), the latter only when COD:N was higher 400:5. The pH was less influenced by the variations in aeration rates, PP concentration and COD:N ratio compared to COD and PP removal. This investigation provides indications about the most suitable operation parameters (airflow rates, inhibiting PP concentration, and optimal COD:N) in aerated lagooning of OMW towards environmentally sound treatments of highly polluting wastewater.

2015 ◽  
Author(s):  
M. Mainuddin ◽  
R. Keanini ◽  
B. Mullany

Although precision polishing of optical grade components using pitch based tools is still common practice, the process has not received the same level of scientific attention as other precision material removal processes. Building on previous research results, this paper demonstrates the relationship between low amplitude, broad spectrum vibrational power input and fused silica material removal rates obtained with different tool-polishing machine combinations. A low cost, easy to implement method of increasing vibrational power is presented and verified through polishing tests. The method uses small, off the shelf, high speed (>10 krpm), DC motors with eccentric masses (0.5 g and 4 g). Attachment of the battery driven motors to the underside of the platen and the workpiece holder increased the vibrational input from 0.7 W to 0.22 W resulting in an increase in the material removal rate from 0.96 mg/hr to 1.10 mg/hr. A method to attenuate process generated vibrations, and thus material removal rates, is also outlined. To achieve this the tool construction is modified by the addition of a cork layer between the substrate and the pitch layer. While this approach is not as flexible as that for increasing the vibrational power input, it successfully attenuated process vibrations (0.2 W to 0.14 W) and reduced the associated material removal rate (9.67 mg/hr to 6.13 mg/hr). The results outlined this paper demonstrate that recording and controlling process vibrations provides practitioners with viable process monitoring and optimization options.


2014 ◽  
Vol 694 ◽  
pp. 372-376
Author(s):  
Nan Zhang ◽  
Yun Wu ◽  
Hong Wei Zhang ◽  
Hui Jia

The characteristics of removing COD and nitrogen simultaneously in membrane aerated biofilm reactor (MABR) was investigated in different packing densities and circulation flow rates. The results show that better removal rates of COD and ammonia nitrogen are found under the packing density of 30%, which removal rates are 76% and 65% respectively. Observations through the electron microscopic and CCD camera reveal that the biofilm have a layered structure and the stable biofilm thickness is 1.652 mm. When the circulation flow rate is 7.62 L·min-1, the highest removal rate of total nitrogen is 70%, meanwhile, the efficient mass transfer of the biofilm is ensured.


1991 ◽  
Vol 24 (5) ◽  
pp. 111-121 ◽  
Author(s):  
M. Kuroda ◽  
Y. Sakakibara

COD removal performance in an anaerobic fixed bed reactor(AAFBR), which treats soluble organic matter, was investigated theoretically by using a simplified biofilm model. The COD removal rate was assumed to be controlled by the decomposition rates of volatile fatty acids such as acetate, propionate and butyrate. The simplified biofilm model took into consideration the effects of intrabiofilm and interbiofilm substrate diffusion rates on substrate biodegradation rates. The COD removal rates in AAFBR were evaluated for various operating conditions by using known kinetic parameters. The calculated results show that the COD removal rates are not affected by adhered biomass provided that the bio-mass is more than about 4 mg-C/cm2, and vary with temperature, bulk liquid substrate concentrations and the bulk liquid flow rates which are in the range 0.01 ~ 1 m/hr. Relations between allowable COD loading rates and packing diameters were shown schematically for different bulk liquid flow rates.


1998 ◽  
Vol 38 (8-9) ◽  
pp. 213-221 ◽  
Author(s):  
Mohamed F. Hamoda ◽  
Ibrahim A. Al-Ghusain

Performance data from a pilot-plant employing the four-stage aerated submerged fixed film (ASFF) process treating domestic wastewater were analyzed to examine the organic removal rates. The process has shown high BOD removal efficiencies (> 90%) over a wide range of hydraulic loading rates (0.04 to 0.68 m3/m2·d). It could also cope with high hydraulic and organic loadings with minimal loss in efficiency due to the large amount of immobilized biomass attained. The organic (BOD and COD) removal rate was influenced by the hydraulic loadings applied, but organic removal rates of up to 104 kg BOD/ m2·d were obtained at a hydraulic loading rate of 0.68 m3/m2·d. A Semi-empirical model for the bio-oxidation of organics in the ASFF process has been formulated and rate constants were calculated based on statistical analysis of pilot-plant data. The relationships obtained are very useful for analyzing the design and performance of the ASFF process and a variety of attached growth processes.


1998 ◽  
Vol 38 (7) ◽  
pp. 19-24 ◽  
Author(s):  
C.-J. Lu ◽  
C. M. Lee ◽  
M.-S. Chung

The comparison of TCE cometabolic removal by methane, toluene, and phenol utilizers was conducted with a series of batch reactors. Methane, toluene, or phenol enriched microorganisms were used as cell source. The initial cell concentration was about 107 cfu/mL. Methane, toluene, and phenol could be readily biodegraded resulting in the cometabolic removal of TCE. Among the three primary carbon sources studied, the presence of phenol provided the best cometabolic removal of TCE. When the concentration of carbon source was 3 mg-C/L, the initial TCE removal rates initiated by methane, toluene, and phenol utilizers were 1.5, 30, and 100 μg/L-hr, respectively. During the incubation period of 80 hours, TCE removal efficiencies were 26% and 96% with the presence of methane and toluene, respectively. However, it was 100% within 20 hours with the presence of phenol. For phenol utilizers, the initial TCE removal rates were about the same, when the phenol concentrations were 1.35, 2.7, and 4.5 mg/L. However, TCE removal was not proportional to the concentrations of phenol. TCE removal was hindered when the phenol concentration was higher than 4.5 mg/L because of the rapid depletion of dissolved oxygen. The presence of toluene also initiated cometabolic removal of TCE. The presence of toluene at 3 and 5 mg/L resulted in similar TCE removal. The initial TCE removal rate was about 95 μg/L-hr at toluene concentrations of 3 and 5 mg/L compared to 20 μg/L-hr at toluene concentration of 1 mg/L.


2000 ◽  
Vol 41 (4-5) ◽  
pp. 253-260 ◽  
Author(s):  
P. Buffière ◽  
R. Moletta

An anaerobic inverse turbulent bed, in which the biogas only ensures fluidisation of floating carrier particles, was investigated for carbon removal kinetics and for biofilm growth and detachment. The range of operation of the reactor was kept within 5 and 30 kgCOD· m−3· d−1, with Hydraulic Retention Times between 0.28 and 1 day. The carbon removal efficiency remained between 70 and 85%. Biofilm size were rather low (between 5 and 30 μm) while biofilm density reached very high values (over 80 kgVS· m−3). The biofilm size and density varied with increasing carbon removal rates with opposite trends; as biofilm size increases, its density decreases. On the one hand, biomass activity within the reactor was kept at a high level, (between 0.23 and 0.75 kgTOC· kgVS· d−1, i.e. between 0.6 and 1.85 kgCOD·kgVS · d−1).This result indicates that high turbulence and shear may favour growth of thin, dense and active biofilms. It is thus an interesting tool for biomass control. On the other hand, volatile solid detachment increases quasi linearly with carbon removal rate and the total amount of solid in the reactor levels off at high OLR. This means that detachment could be a limit of the process at higher organic loading rates.


2012 ◽  
Vol 44 (2) ◽  
pp. 75-93
Author(s):  
Peter Mortensen

This essay takes its cue from second-wave ecocriticism and from recent scholarly interest in the “appropriate technology” movement that evolved during the 1960s and 1970s in California and elsewhere. “Appropriate technology” (or AT) refers to a loosely-knit group of writers, engineers and designers active in the years around 1970, and more generally to the counterculture’s promotion, development and application of technologies that were small-scale, low-cost, user-friendly, human-empowering and environmentally sound. Focusing on two roughly contemporary but now largely forgotten American texts Sidney Goldfarb’s lyric poem “Solar-Heated-Rhombic-Dodecahedron” (1969) and Gurney Norman’s novel Divine Right’s Trip (1971)—I consider how “hip” literary writers contributed to eco-technological discourse and argue for the 1960s counterculture’s relevance to present-day ecological concerns. Goldfarb’s and Norman’s texts interest me because they conceptualize iconic 1960s technologies—especially the Buckminster Fuller-inspired geodesic dome and the Volkswagen van—not as inherently alienating machines but as tools of profound individual, social and environmental transformation. Synthesizing antimodernist back-to-nature desires with modernist enthusiasm for (certain kinds of) machinery, these texts adumbrate a humanity- and modernity-centered post-wilderness model of environmentalism that resonates with the dilemmas that we face in our increasingly resource-impoverished, rapidly warming and densely populated world.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2298
Author(s):  
Pablo Cano Marchal ◽  
Chiara Sanmartin ◽  
Silvia Satorres Martínez ◽  
Juan Gómez Ortega ◽  
Fabio Mencarelli ◽  
...  

The organoleptic profile of a Virgin Olive Oil is a key quality parameter that is currently obtained by human sensory panels. The development of an instrumental technique capable of providing information about this profile quickly and online is of great interest. This work employed a general purpose e-nose, in lab conditions, to predict the level of fruity aroma and the presence of defects in Virgin Olive Oils. The raw data provided by the e-nose were used to extract a set of features that fed a regressor to predict the level of fruity aroma and a classifier to detect the presence of defects. The results obtained were a mean validation error of 0.5 units for the prediction of fruity aroma using lasso regression; and 88% accuracy for the defect detection using logistic regression. Finally, the identification of two out of ten specific sensors of the e-nose that can provide successful results paves the way to the design of low-cost specific electronic noses for this application.


Author(s):  
Alif Chebbi ◽  
Massimiliano Tazzari ◽  
Cristiana Rizzi ◽  
Franco Hernan Gomez Tovar ◽  
Sara Villa ◽  
...  

Abstract Within the circular economy framework, our study aims to assess the rhamnolipid production from winery and olive oil residues as low-cost carbon sources by nonpathogenic strains. After evaluating various agricultural residues from those two sectors, Burkholderia thailandensis E264 was found to use the raw soluble fraction of nonfermented (white) grape marcs (NF), as the sole carbon and energy source, and simultaneously, reducing the surface tension to around 35 mN/m. Interestingly, this strain showed a rhamnolipid production up to 1070 mg/L (13.37 mg/g of NF), with a higher purity, on those grape marcs, predominately Rha-Rha C14-C14, in MSM medium. On olive oil residues, the rhamnolipid yield of using olive mill pomace (OMP) at 2% (w/v) was around 300 mg/L (15 mg/g of OMP) with a similar CMC of 500 mg/L. To the best of our knowledge, our study indicated for the first time that a nonpathogenic bacterium is able to produce long-chain rhamnolipids in MSM medium supplemented with winery residues, as sole carbon and energy source. Key points • Winery and olive oil residues are used for producing long-chain rhamnolipids (RLs). • Both higher RL yields and purity were obtained on nonfermented grape marcs as substrates. • Long-chain RLs revealed stabilities over a wide range of pH, temperatures, and salinities


Author(s):  
Jakub Zdarta ◽  
Katarzyna Jankowska ◽  
Karolina Bachosz ◽  
Oliwia Degórska ◽  
Karolina Kaźmierczak ◽  
...  

Abstract Purpose of Review In the presented review, we have summarized recent achievements on the use of immobilized oxidoreductases for biodegradation of hazardous organic pollutants including mainly dyes, pharmaceuticals, phenols, and bisphenols. In order to facilitate process optimization and achievement of high removal rates, effect of various process conditions on biodegradation has been highlighted and discussed. Recent Findings Current reports clearly show that immobilized oxidoreductases are capable of efficient conversion of organic pollutants, usually reaching over 90% of removal rate. Further, immobilized enzymes showed great recyclability potential, allowing their reuse in numerous of catalytic cycles. Summary Collected data clearly indicates immobilized oxidoreductases as an efficient biocatalytic tools for removal of hazardous phenolic compounds, making them a promising option for future water purification. Data shows, however, that both immobilization and biodegradation conditions affect conversion efficiency; therefore, process optimization is required to achieve high removal rates. Nevertheless, we have demonstrated future trends and highlighted several issues that have to be solved in the near-future research, to facilitate large-scale application of the immobilized oxidoreductases in wastewater treatment.


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