Effect of chemical treatment on soluble residual COD in textile wastewaters

H. Dulkadiroglu; S. Dogruel; D. Okutman; I. Kabdaşlı; S. Sözen; D. Orhon

doi:10.2166/wst.2002.0433

Effect of chemical treatment on soluble residual COD in textile wastewaters

Water Science & Technology ◽

10.2166/wst.2002.0433 ◽

2002 ◽

Vol 45 (12) ◽

pp. 251-259 ◽

Cited By ~ 10

Author(s):

H. Dulkadiroglu ◽

S. Dogruel ◽

D. Okutman ◽

I. Kabdaşlı ◽

S. Sözen ◽

...

Keyword(s):

Particulate Matter ◽

Chemical Treatment ◽

Biological Treatment ◽

Post Treatment ◽

Cod Removal ◽

Minor Portion ◽

Pre Treatment ◽

A Minor ◽

Textile Wastewaters ◽

Fabric Finishing

The effect of chemical treatment on the magnitude of soluble residual COD in the biological treatment effluent is investigated for knit fabric finishing wastewater. Bentonite is selected for its potential to remove soluble COD together with color and particulate components. Chemical treatment using bentonite, when applied prior to biological treatment removes around 40% of the biodegradable as well as soluble inert COD initially present in the wastewater. As a chemical post-treatment, it acts as a polishing step, removing particulate matter and a minor portion of around 20% of the remaining soluble COD. These findings suggest chemical pre-treatment as a better alternative for the optimization of soluble COD removal.

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Characterization and treatability studies of cigarette industry wastewaters: a case study

Water Science & Technology ◽

10.2166/wst.1997.0485 ◽

1997 ◽

Vol 36 (2-3) ◽

pp. 69-74

Author(s):

G. Bozarslan ◽

S. K. Çelebi ◽

F. Sengül

Keyword(s):

Chemical Treatment ◽

Biological Treatment ◽

Continuous System ◽

Cod Removal ◽

Optimum Dose ◽

Fenton Reagent ◽

Cigarette Industry ◽

Settling Behaviour ◽

Characterization Studies

In this study, the wastewater of one of the cigarette factories in Izmir was characterized and treatability studies were done. The characterization studies of the wastewater showed that the COD, and the pH changes drastically. The chemical treatability studies of the influent wastewater were done by using Ca(OH)2, FeCl3 and Fenton Reagent. The optimum dose of FeCI3 was determined by jar tests. When using Ca(OH)2, the best flocculation, settling behaviour, and the highest COD removal occurred around pH 11. The optimum doses of Fenton Reagent (FeSO4 and H2O2) were determined. The supernatants of the previously chemically treated wastewaters were used for biological treatment. According to total COD removal efficiencies and the amount of sludge production during chemical treatment, FeCl3 was found to be the most economical and effective coagulant. Chemical treatment units were designed for a batch and a continuous system. The batch system has more advantages than a continuous system in this case.

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Influence of physico-chemical treatment on the subsequent biological process treating paper industry wastewater

Water Science & Technology ◽

10.2166/wst.2012.155 ◽

2012 ◽

Vol 66 (1) ◽

pp. 217-223 ◽

Cited By ~ 2

Author(s):

Mouhamed el khames Saad ◽

Younes Moussaoui ◽

Asma Zaghbani ◽

Imen Mosrati ◽

Elimame Elaloui ◽

...

Keyword(s):

Chemical Oxygen Demand ◽

Chemical Treatment ◽

Biological Treatment ◽

Biological Process ◽

Paper Industry ◽

Oxygen Demand ◽

Physico Chemical ◽

Biodegradation Study ◽

Pre Treatment ◽

Industry Wastewater

The present paper presents the main results of the biodegradation study of paper industry wastewater through physico-chemical treatment. Indeed, around 60% of chemical oxygen demand (COD) removal can be achieved by electroflocculation treatment. Furthermore, a removal efficiency of the COD of almost 91% has been obtained by biological treatment, with activated amount of sludge for 24 h of culture. Concerning the physico-chemical pre-treatment of the untreated, filtered and electroflocculated rejection effluents, it has been investigated through the degradation curve of COD studies.

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Troubleshooting Foaming in Membrane Bioreactor: Review of Foam Analysis, Causes and Remedies

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.d6591.1110421 ◽

2021 ◽

Vol 10 (4) ◽

pp. 154-170

Author(s):

Gayatri Gawande ◽

◽

Rucha Dandekar ◽

Omparv Channa ◽

Harshali Birari ◽

...

Keyword(s):

Chemical Treatment ◽

Biological Treatment ◽

Membrane Bioreactor ◽

Membrane Bioreactors ◽

Physical Methods ◽

Conventional Activated Sludge ◽

Pre Treatment ◽

Compact Design ◽

Polyaluminium Chloride ◽

Activated Sludge Systems

Membrane Bioreactors have proved to be a useful alternative to conventional activated sludge systems for wastewater treatment. Merits of membrane bioreactors include more compact design saving a significant amount of space and lower sludge production due to longer sludge retention time. This system unfortunately has a downside with it comes to excessive foaming. Membrane bioreactors often act as foam traps leading to overflowing, wastage of sludge and difficulty in process control. Pre-Treatment of wastewater has proven to significantly reduce foaming caused by surfactants. Generally, physical methods are considered more economical and operationally convenient compared to conventional techniques including chemical treatment and advanced techniques like biological treatment. Polyaluminium chloride as a coagulant is recommended as a chemical treatment due to economic and effectiveness considerations. It has been concluded that the remedies for foaming issue are case specific and should be determined by the causes of foaming. This paper aims at reviewing techniques to analyse the foaming phenomenon, causes of foaming and its remedies to manage or eliminate foam.

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A novel and cost-effective sewage treatment system consisting of UASB pre-treatment and aerobic post-treatment units for developing countries

Water Science & Technology ◽

10.2166/wst.1997.0447 ◽

1997 ◽

Vol 36 (12) ◽

pp. 189-197 ◽

Cited By ~ 24

Author(s):

Izarul Machdar ◽

Hideki Harada ◽

Akiyoshi Ohashi ◽

Yuji Sekiguchi ◽

Hiroyuki Okui ◽

...

Keyword(s):

Developing Countries ◽

Low Cost ◽

Sewage Treatment ◽

Cost Effective ◽

Post Treatment ◽

Cod Removal ◽

Treatment System ◽

Treatment Unit ◽

Pre Treatment ◽

Sewage Treatment System

A novel sewage treatment system was proposed, which consists of a UASB anaerobic pre-treatment unit and the following DHS (downflow hanging sponge-cubes) aerobic post-treatment unit, as a low-cost and easy-maintenance process for developing countries. Over six months experiment by feeding sewage our proposed system achieved 94% of total-COD removal, 81% of soluble-COD removal, and nearly perfect SS removal and total-BOD removal at the overall HRT of 8.3 hr (7 hr in UASB and 1.3 hr in DHS unit). Moreover, the DHS reactor was capable of performing high (73–78%) nitrification. Our whole system requires neither external aeration input nor withdrawal of excess sludge.

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Photocatalytic degradation of wastewater from manufactured fiber by titanium dioxide suspensions in aqueous solution: a feasibility study

Water Science & Technology ◽

10.2166/wst.2000.0501 ◽

2000 ◽

Vol 42 (5-6) ◽

pp. 95-99 ◽

Cited By ~ 1

Author(s):

Y.H. Hsieh ◽

K.H. Wang ◽

R.C. Ko ◽

C.Y. Chang

Keyword(s):

Titanium Dioxide ◽

Removal Efficiency ◽

Biological Treatment ◽

Ph Value ◽

Cod Removal ◽

Cod Removal Efficiency ◽

Fiber Plant ◽

Decreasing Ph ◽

Pre Treatment ◽

Raw Wastewater

This investigation used wastewater from manufactured fiber plant for studying the effect of controlling variables on the COD removal efficiency by photocatalyzed degradation of organic pollutants in the presence of titanium dioxide catalyst. By using BOD/COD ratio as index, the treatment of raw wastewater was evaluated for its change of biodegradability as a feasibility in the pre-treatment of biological treatment. The experimental results indicated that with the Janssen Chemica TiO2 as catalyst, the optimal addition was 0.25 g/L with increasing COD removal for decreasing pH value. Both increased light intensity and continuous aeration increased COD removal efficiency, particularly under continuous aeration for significantly raising the ratio of BOD/COD to improve efficiency of subsequent biological treatment.

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A new process for the combined treatment of municipal wastewaters and landfill leachates in coastal areas

Water Science & Technology ◽

10.2166/wst.2002.0156 ◽

2002 ◽

Vol 46 (8) ◽

pp. 111-118 ◽

Cited By ~ 14

Author(s):

C. Yangin ◽

S. Yilmaz ◽

M. Altinbas ◽

I. Ozturk

Keyword(s):

Biological Treatment ◽

Combined Treatment ◽

Post Treatment ◽

Treatment System ◽

Anaerobic Sludge ◽

Stoichiometric Ratio ◽

Landfill Leachates ◽

Magnesium Ammonium Phosphate ◽

Ammonia Stripping ◽

Pre Treatment

One of the most convenient methods for leachate control is to treat landfill leachates with domestic wastewaters. In this framework, a two-stage treatment system including anaerobic pre-treatment combined with a chemical post-treatment system such as ammonia stripping and/or Magnesium Ammonium Phosphate (MAP) precipitation can be comparable with a conventional secondary biological treatment. In this study, 2.5% and 2% of leachate by volume was mixed with domestic wastewater as the feed for the mesophilic Upflow Anaerobic Sludge Bed Reactor (UASBR). pH, feed strength and hydraulic retention time (HRT) were monitored for the evaluation of the performance of the anaerobic process. The HRT's varied from 0.76 to 0.52 d and 58% and 85% COD removal efficiencies were obtained at Organic Loading Rates (OLR) of 0.63 and 2 kg COD/m3.d respectively. The average biomass (VS) concentration in the reactor increased from 40 g/l to 50 g/l during the study. Effluents from the UASBR were further treated chemically either with lime for ammonia stripping or with MAP precipitation. MAP precipitation was applied both at the stoichiometric ratio (Mg:NH4:PO4 = 1:1:1) and above the stoichiometric ratio (Mg:NH4:PO4 = 1:1:1.3). Maximum NH4 removal of 66% was achieved at the pH of 9.3 at the stoichiometric ratio, whereas 86% NH4 removal was obtained at the pH of 9.3 above the stoichiometric ratio. Alternatively, ammonia stripping was applied either to the effluents directly taken from the anaerobic reactor or to the effluents to which MAP precipitation was applied stoichiometrically. Ammonia stripping was conducted for 24 h and 89% NH4 removal was observed at the end of 24 h. Consequently, this study indicates that anaerobic pre-treatment combined with chemical post-treatment (MAP) produced high quality of effluent comparable to the conventional biological treatment especially in terms of N and P levels.

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Effect of chemical and biological treatment on COD fingerprints of textile wastewaters

Water Science & Technology ◽

10.2166/wst.2007.332 ◽

2007 ◽

Vol 55 (10) ◽

pp. 277-287 ◽

Cited By ~ 10

Author(s):

E. Dulekgurgen ◽

S. Doğruel ◽

D. Orhon

Keyword(s):

Size Distribution ◽

Chemical Treatment ◽

Biological Treatment ◽

Size Range ◽

Soluble Fraction ◽

Size Spectrum ◽

Total Removal ◽

Before And After ◽

Treatment Alternatives ◽

Textile Wastewaters

Particle size distribution (PSD) via sequential filtration/ultrafiltration was used as the tool for COD fractionation and colour profiling of textile wastewaters before and after treatment. Profiles prior to treatment suggested PSD-based COD fingerprints characteristic for the influents. Treatment efficiencies were determined via comparing the profiles of the effluents from chemical- and biological-treatment to those of the corresponding influents. COD fingerprints of the wastewaters from the textile plants, applying different treatment alternatives, were different especially at the upper size range; yet profiles after treatment were similar, with the soluble fraction (<2 nm) being almost the only apparent one. Half of the overall COD-removal via chemical treatment was at the particulate- and upper colloidal-ranges, revealing that this alternative was effective at higher ranges, but not at the soluble fraction. In contrast, biological treatment was effective at both ends of size distribution, with total removal at the particulate range and 50% elimination at the soluble portion. Overall colour content and PSD-based colour profiles of the influents were also different. Chemical treatment was successful in removing colour originating from the entire colloidal range, but was not efficient at the soluble fraction. Conversely, colour removal efficiency of biological treatment was moderate throughout the entire size spectrum.

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Cytoprotective Effect of Tocotrienol-Rich Fraction and α-Tocopherol Vitamin E Isoforms Against Glutamate-Induced Cell Death in Neuronal Cells

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000201 ◽

2014 ◽

Vol 84 (3-4) ◽

pp. 0140-0151 ◽

Cited By ~ 11

Author(s):

Thilaga Rati Selvaraju ◽

Huzwah Khaza’ai ◽

Sharmili Vidyadaran ◽

Mohd Sokhini Abd Mutalib ◽

Vasudevan Ramachandran ◽

...

Keyword(s):

Vitamin E ◽

Cell Viability ◽

Neuronal Cells ◽

Positive Control ◽

Post Treatment ◽

Mitochondrial Activity ◽

Before And After ◽

Pre Treatment ◽

Tocotrienol Rich Fraction ◽

Major Mediator

Glutamate is the major mediator of excitatory signals in the mammalian central nervous system. Extreme amounts of glutamate in the extracellular spaces can lead to numerous neurodegenerative diseases. We aimed to clarify the potential of the following vitamin E isomers, tocotrienol-rich fraction (TRF) and α-tocopherol (α-TCP), as potent neuroprotective agents against glutamate-induced injury in neuronal SK-N-SH cells. Cells were treated before and after glutamate injury (pre- and post-treatment, respectively) with 100 - 300 ng/ml TRF/α-TCP. Exposure to 120 mM glutamate significantly reduced cell viability to 76 % and 79 % in the pre- and post-treatment studies, respectively; however, pre- and post-treatment with TRF/α-TCP attenuated the cytotoxic effect of glutamate. Compared to the positive control (glutamate-injured cells not treated with TRF/α-TCP), pre-treatment with 100, 200, and 300 ng/ml TRF significantly improved cell viability following glutamate injury to 95.2 %, 95.0 %, and 95.6 %, respectively (p < 0.05).The isomers not only conferred neuroprotection by enhancing mitochondrial activity and depleting free radical production, but also increased cell viability and recovery upon glutamate insult. Our results suggest that vitamin E has potent antioxidant potential for protecting against glutamate injury and recovering glutamate-injured neuronal cells. Our findings also indicate that both TRF and α-TCP could play key roles as anti-apoptotic agents with neuroprotective properties.

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CONTRACEPTION BY AN INJECTABLE LONG-ACTING OESTROGEN-PROGESTOGEN AGENT. III

Acta Endocrinologica ◽

10.1530/acta.0.0690067 ◽

1972 ◽

Vol 69 (1) ◽

pp. 67-76

Author(s):

Rolf Plesner

Keyword(s):

Treatment Period ◽

Treatment Cycle ◽

Post Treatment ◽

Mixed Phase ◽

Discontinuation Of Treatment ◽

Phase Type ◽

Secretory Type ◽

Pre Treatment ◽

Long Acting ◽

Fertile Women

ABSTRACT Twenty-two fertile women were treated cyclically in from 4–30 cycles (mean 15.5) with a total of 341 injections of Deladroxate®, an injectable, long-acting oestrogen-progestogen. The injections were administered on the 8th (7th–9th) day of each cycle. Before treatment, the last pre-treatment cycle was controlled by means of daily recordings of the basal body temperature (BBT), urinary excretion of pregnanediol and total pituitary gonadotrophins at certain intervals, and by endometrial biopsies obtained late in the cycle. The effects of Deladroxate® on ovulation, on pituitary gonadotrophic function, and on the endometrium were controlled by the above mentioned parameters during cycles 1, 3, and 6, and all assessments were repeated after discontinuation of treatment. During treatment, there was a statistically significant fall in gonadotrophin excretion values (as compared with the pre-treatment values), and the fall was found to be gradually progressive during treatment. After discontinuation of treatment, there seemed to be a tendency towards an increase in the excretion values. Suppression of ovulation as determined by means of the pregnanediol excretion during treatment, was effective in nearly all of the treatment cycles checked. The fall in pregnanediol excretion was also gradually progressive during treatment, while there was a slight increase in excretion values in the post-treatment period. During treatment, 79 BBT curves were recorded. Nearly 50 % were monophasic, indicating anovulatory cycles, 17 curves were biphasic, but with the rise in temperature occurring at non-characteristic times in the cycles, 18 curves were classified as thermogenic because of a rise in temperature occurring within 24 hours after the injection, and 5 curves were not assessable. During the first month after discontinuation of treatment, 8 out of 10 recorded curves were monophasic. Out of 53 endometrial biopsies obtained around the 23rd day of the cycle, 31 were of the mixed phase type, but showing a predominance of proliferative patterns, 15 were of the secretory type, and 7 were purely proliferative. Out of 15 biopsies obtained in the post-treatment period, only two were of the mixed phase type, 12 were proliferative and one was purely secretory.

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