Effect of dissolved metals on the organic load removal efficiency of Lemna gibba

1999 ◽  
Vol 33 (2) ◽  
pp. 530-538 ◽  
Author(s):  
Nicoletta Boniardi ◽  
Renato Rota ◽  
Giuseppe Nano
2018 ◽  
Vol 7 (4.34) ◽  
pp. 389
Author(s):  
Ashwin Charles ◽  
Chin Kui Cheng

Palm oil mill effluent (POME) pollution is a serious issue that has gained the attention of an international audience including policy makers, mill owners, NGOs and academicians. With a production rate of 74 million metric tonnes a year, Malaysia is in dire need for new technologies able to address this mounting problem. While previous research has attempted to modify existing microbial driven organic degradation methods to optimize the organic load removal, new studies recognize the futility in this endeavour as mills are unwilling to change the way they operate and adopt these disruptive technologies. Instead current research aims at tertiary polishing technologies of which photocatalysis has emerged as a forerunner. Recent advances indicate photocatalytic treatment of POME is a viable solution to the problem but for it to be cost effective, future studies should focus on visible light driven processes and new reactor configurations to improve the photocatalytic activity of existing systems.  


2005 ◽  
Vol 52 (1-2) ◽  
pp. 391-396 ◽  
Author(s):  
F.J. Almendariz ◽  
M. Meraz ◽  
A.D. Olmos ◽  
O. Monroy

Refinery spent caustics (SC) were diluted with sour waters (SW) in a ratio 1:7, neutralized with CO2 (SC/SWCO2) and 83% of H2S was striped during this procedure, remaining an aromatic portion that contained 2123, 2730 and 1379 mg L−1 of phenol, p-cresol and o-cresol, respectively. The mixture was treated anaerobically in an EGSB reactor fed with 1.5 gCOD L−1 d−1, without mineral supplements causing loss of COD removal efficiency that dropped to 23%, methane production ceased and no phenol or cresols were biodegraded. The EGSB experiments were resumed by feeding the reactor with nutrients and phenol at 1.0 gCOD L−1 d−1. The mixture SC/SWCO2 added to the phenol load, was step increased from 0.10 to 0.87 gCOD L−1 d−1 maximum. When total organic load was increased to 1.6, COD removal efficiency was 90% and at the highest load attained, 1.87, efficiency dropped to 23% attributed to the toxic effect produced by cresols.


2006 ◽  
Vol 54 (8) ◽  
pp. 17-25 ◽  
Author(s):  
E. Bettazzi ◽  
M. Morelli ◽  
S. Caffaz ◽  
C. Caretti ◽  
E. Azzari ◽  
...  

Olive oil production, one of the main agro-industries in Mediterranean countries, generates significant amounts of olive mill wastewaters (OMWs), which represent a serious environmental problem, because of their high organic load, the acidic pH and the presence of recalcitrant and toxic substances such as phenolic and lipidic compounds (up to several grams per litre). In Italy, traditional disposal on the soil is the most common way to discharge OMWs. This work is aimed at investigating the efficiency and feasibility of AOPs and biological processes for OMW treatment. Trials have been carried out on wastewaters taken from one of the largest three-phase mills of Italy, located in Quarrata (Tuscany), as well as on synthetic solutions. Ozone and Fenton's reagents applied both on OMWs and on phenolic synthetic solutions guaranteed polyphenol removal efficiency up to 95%. Aerobic biological treatment was performed in a batch reactor filled with raw OMWs (pH =4.5, T=30 °C) without biomass inoculum. A biomass rich of fungi, developed after about 30 days, was able to biodegrade phenolic compounds reaching a removal efficiency of 70%. Pretreatment of OMWs by means of oxidation increased their biological treatability.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4821
Author(s):  
Annabel Fernandes ◽  
Maria João Nunes ◽  
Ana Sofia Rodrigues ◽  
Maria José Pacheco ◽  
Lurdes Ciríaco ◽  
...  

Complex wastewater matrices present a major environmental concern. Besides the biodegradable organics, they may contain a great variety of toxic chemicals, heavy metals, and other xenobiotics. The electrochemically activated persulfate process, an efficient way to generate sulfate radicals, has been widely applied to the degradation of such complex effluents with very good results. This review presents the fundamentals of the electro-persulfate processes, highlighting the advantages and limitations, followed by an exhaustive evaluation on the application of this process for the treatment of complex industrial effluents. An overview of the main relevant experimental parameters/details and their influence on the organic load removal is presented and discussed, having in mind the application of these technologies at an industrial scale. Finally, the future perspectives for the application of the electro-persulfate processes in the treatment of complex wastewater matrices is outlined.


2005 ◽  
Vol 51 (10) ◽  
pp. 301-310 ◽  
Author(s):  
H.-B. Jun ◽  
S.-M. Park ◽  
J.-K. Park ◽  
S.-H. Lee

Equalization characteristics of the upflow sludge blanket – aerated bio-filter (USB-AF) were investigated with the fluctuated raw domestic sewage. Recycle of nitrified effluent from AF to USB triggered the equalization characteristics of the sludge blanket on both soluble and particulate organic matter. Increment of EPS in sludge blanket by nitrate recycle was detected and removal of turbidity and particulates increased at higher recycle ratios by bio-flocculation. Increased TCOD removal in the USB was due to both denitrification of recycled nitrate and entrapment of the particulate organic matter in sludge blanket. Capture of both soluble and particulate organic matter increased sludge blanket layer in the USB, which improved the reactor performances and reduced the organic load on the subsequent AF. Overall TCOD and SS removal efficiencies were about 98% and 96%, respectively in the USB-AF system. Turbidity in the USB effluent was about 44, 20 and 5.5 NTU, at recycle ratios of 0, 100 and 200%, respectively. Particle counts in the range 2–4 μm in the USB effluent were higher than those in influent without nitrate recycle, while particle counts in the range of 0.5–15 μm in the USB effluent decreased 70% at recycle ratio of 200%. The major constituent of EPS extracted from anaerobic sludge was protein and total EPS increased from 109.1 to 165.7 mg/g-VSS with nitrate recycle of 100%. Removal efficiency and concentration of T-N in the UBS-AF effluent was over 70% and below 16 mg/L, respectively.


2018 ◽  
Vol 34 (6) ◽  
pp. 3100-3105
Author(s):  
Nyimas Yanqoritha ◽  
Muhammad Turmuzi ◽  
Irvan Irvan ◽  
Fatimah Batubara ◽  
Ilmi Ilmi

Wastewater of tofu industry contains very high organic content, then anaerobic process is the most suitable for degrading this liquid waste. The hybrid upflow anaerobic sludge blanket reactor (HUASBR) was applied in this study because it has the advantage in ensuring good contact between biomass and substrate where a suspension medium and anaerobic filter are able to withstand more biomass in the attached media. Processing Anaerobic process is carried out with the help of bacteria where bacteria need seeding and acclimatization. Acclimatization is the process of adaptation of microorganisms to wastewater to be treated. This adaptation process is carried out by adding waste water from the smallest concentration to the actual concentration. The purpose of this study is to determine the effect of variations in organic load rate (OLR) on the acclimatization process in removing COD, biogas production in accordance with the pH of the anaerobic degradation process so that the optimal process of the acclimatization process can be obtained. In this study, the acclimatization process took 200 days with variation of OLR in the range of 1.5 - 5.9 kg COD m-3 d-1 at HRT 24 hours and flow rate up (Vup) of 0.08 m/h. The objective of OLR variation was to evaluate acclimatization process on the HUASBR performance during process optimization. The highest biogas production and removal efficiency of COD were achieved in pH range of 6.5 - 7.6. While, the highest COD removal efficiency obtained was 86.57% on the 140th day and biogas production 7700 ml for OLR 4.8 kg COD m-3d-1 at HRT 24 h. Consequently, the optimum OLR for treating the tofu wastewater could be achieved up to 4.8 kg COD m-3d-1 and HRT 24h.


1995 ◽  
Vol 32 (12) ◽  
pp. 121-129 ◽  
Author(s):  
A. Espinosa ◽  
L. Rosas ◽  
K. Ilangovan ◽  
A. Noyola

A laboratory UASB reactor was fed with cane molasses stillage at organic loadings from 5 to 21.5 kg COD/m3 d. With an organic load of 17.4 kg COD/m3 d, an accumulation of VFA, principally propionic acid, was observed due to little bioavailability or lack of trace metals (Fe, Ni, Co and Mo). Associated to this, the performance of the UASB reactor was low (44% COD removal efficiency), with an alkalinity ratio above 0.4. The addition of Fe (100 mg/l), Ni (15 mg/l), Co (10 mg/l) and Mo (0.2 mg/l) to the influent reduced significantly the level of propionic acid (5291mg/l to 251 mg/l) and acetic acid (1100 mg/l to 158 mg/l). The COD removal efficiency increased from 44% to 58%, the biogas production from 10.7 to 14.8 l/d (NTP) and 0.085 to 0.32 g CH4-COD/g SSV d for specific sludge methanogenic activity with propionic acid as substrate. These improved results were obtained with high COD (68.9 g/l) and organic load (21.5 kg COD/m3 d).


2020 ◽  
Vol 8 (10) ◽  
pp. 1588
Author(s):  
Graziella Chuppa-Tostain ◽  
Melissa Tan ◽  
Laetitia Adelard ◽  
Alain Shum-Cheong-Sing ◽  
Jean-Marie François ◽  
...  

Sugarcane Distillery Spent Wash (DSW) is among the most pollutant industrial effluents, generally characterized by high Chemical Oxygen Demand (COD), high mineral matters and acidic pH, causing strong environmental impacts. Bioremediation is considered to be a good and cheap alternative to DSW treatment. In this study, 37 strains of yeasts and filamentous fungi were performed to assess their potential to significantly reduce four parameters characterizing the organic load of vinasses (COD, pH, minerals and OD475nm). In all cases, a pH increase (until a final pH higher than 8.5, being an increase superior to 3.5 units, as compared to initial pH) and a COD and minerals removal could be observed, respectively (until 76.53% using Aspergillus terreus var. africanus and 77.57% using Aspergillus niger). Depending on the microorganism, the OD475nm could decrease (generally when filamentous fungi were used) or increase (generally when yeasts were used). Among the strains tested, the species from Aspergillus and Trametes genus offered the best results in the depollution of DSW. Concomitant with the pollutant load removal, fungal biomass, with yields exceeding 20 g·L−1, was produced.


2009 ◽  
Vol 60 (4) ◽  
pp. 1025-1031 ◽  
Author(s):  
A. R. C. Ortigara ◽  
P. H. Sezerino ◽  
A. P. Bento ◽  
D. Scaratti

This paper analyses variations in the quali-quantitative characterization of winery wastewater, and the behavior of the treatment of these effluents. The wastewater produced is sent to two disposition systems: Point A receives the wastewater from the production area whereas Point B receives the wastewater from the area where the washing of bottles takes place. Two Aerated Submerged Biofilter (ASB) reactors (with oyster shells as support material) were built at lab scale to promote the treatment of the winery effluent. Water usage and effluent production values of the 2008 harvest season indicate that grape processing accounted for 30% of the total water usage. The median value found for the effluent at Point A was 8,260 mg COD L−1 and at Point B 358 mg COD L−1. The average C/N/P ratio found at Point A was 100/0.29/0.28 during the harvest and 100/0.27/0.25 during the non harvest. For ASB 1 the COD removal efficiency ranged from 56% to 90%, with the removed organic load ranging from 1.5 kg COD m−3 d−1 to 2.7 kg COD m−3 d−1, respectively. For ASB 2 the COD removal efficiency ranged from 63% to 82%, with the removed organic load ranging from 1.8 kg COD m−3 d−1 to 1.7 kg COD m−3 d−1, respectively.


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