scholarly journals Comparison of naturally prepared coagulants for removal of COD and color from textile wastewater

2013 ◽  
Vol 15 (4) ◽  
pp. 522-528 ◽  

<p>The wastewater generated by the textile industry is rated as the most polluting among all industrial sectors considering both volumes discharged and effluent composition. Present investigation intended for COD and color removal from textile wastewater using naturally prepared coagulants i.e. Surjana Seed Powder (SSP), Maize Seed Powder (MSP) and Chitosan. Effect of coagulant dose, flocculation time and temperature has been studied. The Sludge Volume Index (SVI) and turbidity were examined for various effects. SSP was more effective than Chitosan and MSP for the removal of COD and color and also, Chitosan was more efficient than SSP and MSP considering SVI and turbidity. Maximum percentage reduction corresponds to 75.6 and 62.8 was obtained for removal of COD and color respectively using SSP.</p>

2019 ◽  

<p>Wastewater from textile industry is considered one of the major environmental challenges due to the large volume of highly colored, polluted and toxic effluent. This study investigated the treatability of real textile wastewater by pilot-scale anoxic-aerobic Membrane Bioreactor (MBR) system without sludge wasting for operation period of 100 days. The proposed system was investigated under different Internal Recycle (IR) ratios and the impact of IR ratio on Total Organic Carbon (TOC), Total Nitrogen (TN) and Color removals were examined. Under IR ratios between anoxic and aerobic tanks of 0.0, 0.5 and 2.0, the respective average removal efficiency of TN was 20.9%,53.4% and 71.7%, whereas average color removal of 81%, 85% and 88%, respectively was noted. The results indicated that increase of recycle ratio from 0.5 to 2.0 enhanced TN removal to about 71% and color removal to above 85%. The IR between anoxic and aerobic tanks has a significant role in TN and color removal due its effect on the development of bacterial communities. On the other hand, the results indicate over 93% TOC removal, which was independent of IR ratio.</p>


2002 ◽  
Vol 45 (12) ◽  
pp. 305-313 ◽  
Author(s):  
D. Orhon ◽  
H. Dulkadiroğlu ◽  
S. Doğruel ◽  
I. Kabdaşli ◽  
S. Sozen ◽  
...  

The study investigates the effect of partial ozonation of textile wastewater, both at the inlet (pre-ozonation) and the outlet (post-ozonation) of biological treatment, for the optimization of COD and color removals, both typical polluting parameters associated with the textile industry. Pre-ozonation provides at optimum contact time of 15 minutes 85% color removal, but only 19% COD reduction. Removal of the soluble inert COD fraction remains at 7%, indicating selective preference of ozone for simpler compounds. Post-ozonation is much more effective on the breakdown of refractory organic compounds and on color removal efficiency. Ozonation after biological treatment results in almost complete color removal and a 14% soluble inert COD reduction. The polishing effect of post-ozonation also proves quite attractive from an economical standpoint, involving approximately 50% of the ozone utilization at the same ozone flux rate and contact time, yet providing a lower soluble residual COD level.


2020 ◽  
Vol 82 (7) ◽  
pp. 1467-1483
Author(s):  
Hanumanthappa Srikantha ◽  
Mahesh Shivaswamy ◽  
Sahana Mahesh

Abstract Copper and stainless steel electrodes were used in batch electrochemical coagulation (BECC) for the treatment of real textile wastewater using 16 electrode combinations. Out of 16 Cu-SS and SS-Cu combinations (eight combinations each), only 4SS and 3SS-1Cu electrodes operated at cell voltage of 18 V and current density of 180 A/m2 gave maximum color and chemical oxygen demand (COD) removals. The COD removal was observed to be 89.37% for 4SS and 72.34% for 3SS 1Cu electrodes from CODo 3,012 mg/L. Color removal was 97% and 98% from its initial value of 1,000 Pt-Co unit for 4SS and 3SS-1Cu combinations. Water quality parameters like total dissolved solids, chloride, nitrate, phosphate, and sulphate reduced from their initial values while using all 4SS and 3SS-1Cu electrode arrangements. Other control factors exercised for optimal operations were ECC floc settling pattern and sludge volume index (SVI). SVI values were found to be &lt;100 mL/g for both electrode combinations.


Processes ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 34 ◽  
Author(s):  
Hua Yin ◽  
Peiwen Qiu ◽  
Yuange Qian ◽  
Zhuwen Kong ◽  
Xiaolong Zheng ◽  
...  

The reduced natural waters and the large amount of wastewater produced by textile industry necessitate an effective water reuse treatment. In this study, a combined two-stage water reuse treatment was established to enhance the quality and recovery rate of reused water. The primary treatment incorporated a flocculation and sedimentation system, two sand filtration units, an ozonation unit, an ultrafiltration (UF) system, and a reverse osmosis (RO) system. The second treatment included an ozonation unit, a sand filtration unit, and UF and RO systems. The color removal rate increased with the increasing ozone dosage, and the relational expression between the ozone dosage and color removal rate was fitted. Ozonation greatly reduced the color by 92.59 and 97.27 times during the primary and second ozonation stages, respectively. RO had the highest removal rate. The combined processes showed good performance in water reuse treatment. The treated, reused water satisfied the reuse standard and surpassed the drinking water standard rates for chemical oxygen consumption (CODcr), color, NH3-N, hardness, Cl−, SO42−, turbidity, Fe3+, and Cu2+. The operating cost of reuse water treatment was approximately 0.44 USD·m−3.


Author(s):  
Nurtaç Öz ◽  
Meryem Yılmaz ◽  
Ahmet Çelebi

The textile industry is an industry that consumes large amounts of water during production, contains various chemicals in its wastewater, conventional treatment methods are insufficient to reduce the wastewater pollution level, and has colloidal substances and color problems. Membrane bioreactor systems provide high efficiency in the treatment of textile wastewater and dyestuff removal. Removal of dyestuffs and turbidity in real textile wastewater by using a laboratory-scale membrane bioreactor system was studied. Chemical precipitation was not applied before the biological treatment for the removal of color and other pollutant parameters. A hollow fiber microfiltration membrane module was used in the system. Then a combination with an active carbon filter was created to take the color removal to a higher level. The development of the microorganism composition adapted to the textile industry was observed in the biological reactor. The system was operated with an endless sludge age and a hydraulic retention time of 24 hours. Color measurement transparency index parameter DFZ (DurchsichtsFarbZahl) was measured in a spectrophotometer at wavelengths of 436, 525, and 620 nm (nanometers) according to EN ISO 7887 standards. In the microfiltration permeate water, the color removal were found in 436 nm: 91-95%, 525 nm: 94-98%, 620 nm: 96-99%, and in activated carbon permeate water, the color removal in 436 nm: 96-99% at 525 nm: 95-99%, 620 nm: 96-99%, respectively. Due to the physical separation of the membrane, which is the simplest definition, high efficiencies in color removal have been achieved in the system. The activated carbon system combined with the membrane was found higher efficiency in color removal than the microfiltration output.


2009 ◽  
Vol 60 (3) ◽  
pp. 683-688 ◽  
Author(s):  
Zaharah Ibrahim ◽  
Mohamad Faiz Mohd Amin ◽  
Adibah Yahya ◽  
Azmi Aris ◽  
Noor Azrimi Umor ◽  
...  

Microbial flocs formed from raw textile wastewater in a prototype Aerobic Biofilm Reactor (ABR) system were characterised and studied for their potential use in the treatment of textile wastewater. After 90–100 days of operation, microbial flocs of loose irregular structures were obtained from the reactor with good settling velocity of 33 m/h and sludge volume index (SVI) of 48.2 mL/g. Molecular analysis of the flocs using PCR-amplified 16S rDNA sequence showed 98% homology to those of Bacillus sp, Paenibacillus sp and Acromobacter sp. Detection of Ca2 + (131 mg/g) and Fe2 + (131 mg/g) using atomic absorption spectrometer might be implicated with the flocs formation. In addition, presence of Co2 +  and Ni2 +  were indicative of the flocs ability to accumulate at least a fraction of the metals' present in the wastewater. When the flocs were used for the treatment of raw textile wastewater, they showed good removal of COD and colour about 55% and 70% respectively, indicating their potential application.


2017 ◽  
Vol 77 (2) ◽  
pp. 511-517 ◽  
Author(s):  
Z. Y. Ozkan ◽  
M. Cakirgoz ◽  
E. S. Kaymak ◽  
E. Erdim

Abstract The effectiveness of green tea (Camellia sinensis) and pomegranate (Punica granatum) extracts for the production of iron nanoparticles and their application for color removal from a textile industry wastewater was investigated. Polyphenols in extracts act as reducing agents for iron ions in aqueous solutions, forming iron nanoparticles. Pomegranate extract was found to have almost a 10-fold higher polyphenolic content than the same amount of green tea extract on a mass basis. However, the size of the synthesized nanoparticles did not show a correlation with the polyphenolic content. 100 ppm and 300 ppm of iron nanoparticles were evaluated in terms of color removal efficiency from a real textile wastewater sample. 300 ppm of pomegranate nanoscale zero-valent iron particles showed more than 95% color removal and almost 80% dissolved organic carbon removal. The degradation mechanisms are is considered to be adsorption and precipitation to a major extent, and mineralization to a minor extent.


2018 ◽  
Vol 81 (1) ◽  
Author(s):  
Suryati Sulaiman ◽  
Azmi Aris ◽  
Abdul Syukor Abd Razak ◽  
Khalida Muda ◽  
Aznah Nor Anuar

Present study aimed at evaluating the formation of biogranules using sequencing batch reactors (SBRs) in treating textile wastewater under the influence of static mixer. Three sets of experiment were run with different superficial air velocity (SAV) of 0.5, 1.4 and 2.1 cms-1, each set consisting of two SBR one with and one without static mixer. The developed biogranules in reactors with static mixer (R1M, R2M and R3M) showed good results after approximately 70 days. The biomass in the reactor reached mix liquor suspended solid (MLSS) of 5.75 gL-1 with sludge volume index (SVI) of 107.4 mLg-1 and settling velocity (SV) of 70.3 mh-1 in R1M; MLSS of 7.18 gL-1 with SVI of 29.5 mLg-1 and SV of 80.4 mh-1 for R2M and MLSS of 7.38 gL-1 with SVI of 36.3 mLg-1 and SV of 74.2 mh-1 for R3M. The use of static mixer has contributed to biogranules development with good settling properties.


2016 ◽  
Vol 74 (4) ◽  
pp. 994-1004 ◽  
Author(s):  
Carlos Eduardo de Farias Silva ◽  
Andreza Heloiza da Silva Gonçalves ◽  
Ana Karla de Souza Abud

Various agricultural residues have been tested as biosorbents due to their low cost, high surface area, and favorable surface chemistry. In this work, a sweet orange albedo was tested as a biosorbent for treatment of real textile effluents. The orange albedo powder was prepared by drying the residue at 50 °C and milling to 30 mesh, and then used for dye adsorption from a alkaline (pH = 10.71) effluent. The adsorption process was studied in batch experiments at 30 °C by measuring color removal and chemical oxygen demand (COD). The color removal was found not to be significantly altered when the effluent was used in its raw state, while COD increased probably due to albedo degradation. For the effluent diluted to 60% (Veffluent VH2O−1), color and COD removal percentages of approximately 89% were obtained. It was found that pH played a very significant role on the adsorption process, as the treated albedo displayed a relative pHPZC* of 4.61, and the highest dye removal efficiencies were reached at pH lower than 2. The COD was strongly influenced by the effluent dilution. The effectiveness in eliminating color and COD shows that orange albedo can be potentially used as a biosorbent to treat textile wastewater.


1997 ◽  
Vol 36 (4) ◽  
pp. 307-312
Author(s):  
Michael R. Rasmussen ◽  
Torben Larsen

An on-line settling column for measuring the dynamic variations of settling velocity of activated sludge has been developed. The settling column is automatic and self-cleansing insuring continuous and reliable measurements. The settling column was tested on sludge from a batch reactor where sucrose was added as an impulse to activated sludge. The continuous measurement of settling velocity revealed a highly dynamic response after the sucrose was added. The results were verified with simultaneous measurement of the initial settling rate. A 200 hour experiment showed variations in settling velocity, which was not apparent in the DSVI (Diluted Sludge Volume Index).


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