Membrane-flocculation-adsorption hybrid system in wastewater treatment: micro and nano size organic matter removal

2004 ◽  
Vol 50 (12) ◽  
pp. 265-271 ◽  
Author(s):  
S. Vigneswaran ◽  
H.K. Shon ◽  
S. Boonthanon ◽  
H.H. Ngo ◽  
R.B. Aim

Cross flow microfiltration with in-line flocculation reduces the fouling of membranes thus leading to high quality product water. A detailed experimental study conducted with an artificial suspension (particle size distribution similar to that of surface water) revealed that the filtration rate can be increased by several times by adopting in-line flocculation. In-line flocculation-microfiltration is therefore an attractive technique to reduce internal clogging while improving the permeate flux significantly. A detailed ultrafiltration (UF) study was conducted with biologically treated sewage effluent with pretreatment by flocculation and powdered activated carbon adsorption. The TOC removal by the NTR 7410 UF membrane alone was 43.6%. The TOC removal increased significantly by the use of pretreatment: 69.3% by flocculation and 91% by flocculation followed by adsorption. The organic colloidal portion (between 3,500 dalton and 0.45 μm) in the biologically treated effluent was removed up to more than 65% by the pretreatment of flocculation. The molecular weight of the biologically treated effluent ranged from 250 to about 3,573 dalton with the highest fraction in the range of 250-845 dalton. By the incorporation of pretreatment, the majority of both large and small molecular weight organic matter was removed. This hybrid system led to practically no filtration flux decline in membrane filtration.

Desalination ◽  
2002 ◽  
Vol 147 (1-3) ◽  
pp. 83-88 ◽  
Author(s):  
R. Thiruvenkatachari ◽  
H.H. Ngo ◽  
P. Hagare ◽  
S. Vigneswaran ◽  
R.Ben Aim

2020 ◽  
Vol 35 (3) ◽  
pp. 464-470 ◽  
Author(s):  
Wenjie Zhao ◽  
Junfei Wu ◽  
Fushan Chen

AbstractThe fundamental reason for the environmental pollution caused by the papermaking industry is the inadequate treatment of the black liquor. How to dispose of the lignin macromolecules, which is the main pollutants in the black liquor, is the key to addressing the environmental pollution. At present, cross-flow membrane filtration is one of the effective ways to retain and recycle lignin macromolecules in black liquor. The paper proposes the adoption of a dynamic blade cross-flow membrane filtration equipment provided by German BOKELA company to treat papermaking black liquor. The experiment shows that when the black liquor is treated with dynamic blade rotation cross-flow, the membrane with a molecular weight cut-off of nanofiltration (NP010) delivers the best retaining effect, with 28 % more lignin in black liquor than that in untreated black liquor. Meanwhile, when the blade rotational speed reaches 300 rpm and the transmembrane pressure is 0.5 or 2 bar, the flux of black liquor through nanofiltration NP010 is relatively desirable.


2013 ◽  
Vol 65 (4) ◽  
Author(s):  
Muhammadameen Hajihama ◽  
Wirote Youravong

Tuna cooking juice is a co-product of tuna canning industry. It riches in protein, currently used for production of feed meal as well as protein hydrolysate. The finish products are usually in the form of concentrate, produced by evaporation process. However, evaporation is energy consumable process and the salt content level of the concentrate is often over the standard, thus required additional process for lowering salt content e.g. crystallization. The use of membrane technology, therefore, is of interest, since it required less energy and footprint compared with evaporation and is also able to reduce salt content of the concentrate. The aim of this study were to employ and select the membrane filtration process, and optimize the operating condition for protein concentration and desalination of tuna cooking juice. The results indicated that nanofiltration (NF) was more suitable than the ultrafiltration (UF) process, regarding the ability in protein recovery and desalination. The NF performance was evaluated in terms of permeation flux and protein and salt retentions. The protein and salt rejections of NF were 96 % and 5 %, respectively. The permeate flux(J) increased as transmembrane pressure (TMP) or cross flow rate (CFR) increased and the highest flux was obtained at TMP of 10 bar and CFR of 800 L/h. Operating with batch mode, the permeate flux was found to decrease as protein concentration increased, and at volume concentration factor about 4, the protein concentration  about 10% while salt removal was aproximately 70 % of the initial value. This work clearly showed that NF was successfully employed for concentration and desalination of protein derived from tuna cooking juice.


Desalination ◽  
2009 ◽  
Vol 237 (1-3) ◽  
pp. 392-399 ◽  
Author(s):  
Kah-Young Song ◽  
Pyung-Kyu Park ◽  
Jae-Hyuk Kim ◽  
Chung-Hak Lee ◽  
Sangho Lee

2008 ◽  
Vol 58 (8) ◽  
pp. 1535-1539 ◽  
Author(s):  
L. Sabina ◽  
B. Kus ◽  
H.-K. Shon ◽  
J. Kandasamy

Organic characterisation in rainwater was investigated in terms of dissolved organic carbon (DOC) and molecular weight distribution (MWD) after powdered activated carbon (PAC) adsorption. PAC adsorption was used as pretreatment to membrane filtration to reduce membrane fouling. The MW of organic matter in rainwater used in this study was in the range of 43,000 Da to 30 Da. Each peak of organic matter consisted of biopolymers (polysaccharides and proteins), humic and fulvic acids, building blocks, low MW acids (hydrolysates of humic substances), low MW neutrals and amphiphilics. Rainwater contained the majority of hydrophilic compounds up to 72%. PAC adsorption removed 33% of total DOC. The removal efficiencies of the hydrophobic and hydrophilic fractions after PAC adsorption were 50% and 27%, respectively. PAC adsorption was found to preferentially remove the hydrophobic fraction. The majority of the smaller MW of 1,100 Da, 820 Da, 550 Da, 90 Da and 30 Da was removed after PAC adsorption. The MFI values decreased from 1,436 s/L2 to 147 s/L2 after PAC adsorption. It was concluded that PAC adsorption can be used as a pretreatment to membrane filtration with rainwater.


1999 ◽  
Vol 40 (9) ◽  
pp. 157-163 ◽  
Author(s):  
Raymond M. Hozalski ◽  
Edward J. Bouwer ◽  
Sudha Goel

Removal of natural organic matter (NOM) in biofilters can be affected by many factors including NOM characteristics, use of pre-ozonation, water temperature, and biofilter backwashing. Laboratory experiments were performed and a biofilter simulation model was developed for the purpose of evaluating the effects of each of these factors on NOM removal in biofilters. Four sources of NOM were used in this study to represent a broad spectrum of NOM types that may be encountered in water treatment. In batch experiments with raw NOM, the removal of organic carbon by biodegradation was inversely proportional to the UV absorbance (254 nm)-to-TOC ratio and directly proportional to the percentage of low molecular weight material (as determined by ultrafiltration). The extent and rate of total organic carbon (TOC) removal typically increased as ozone dose increased, but the effects were highly dependent on NOM characteristics. NOM with a higher percentage of high molecular weight material experienced the greatest enhancement in biodegradability by ozonation. The performance of laboratory-scale continuous-flow biofilters was not significantly affected by periodic backwashing, because backwashing was unable to remove large amounts of biomass from the filter media. Model simulations confirmed our experimental results and the model was used to further evaluate the effects of temperature and backwashing on biofilter performance.


1988 ◽  
Vol 20 (1) ◽  
pp. 161-170 ◽  
Author(s):  
O. Milstein ◽  
A. Haars ◽  
A. Majcherczyk ◽  
J. Trojanowski ◽  
D. Tautz ◽  
...  

Organic matter from spent bleaching effluents (from chlorination (C) or extraction (E) stages, or a mixture of both) was effectively precipitated as a water insoluble complex with polyethyleneimine (polyimine). Precipitation was performed in a pilot unit operating automatically. The colour, chemical oxygen demand (COD), and adsorbable organic halogens (AOX) were reduced in the C-effluent by up to 92%, 65%, and 84%, respectively. Regarding the E-stage effluent, reduction was up to 76% for colour, 70% for COD, and 73% for AOX. No significant reduction of BOD5 was observed in the supernatant of the treated effluent. Fish toxicity was greatly reduced. Laccase increased the molecular weight of the effluent constituents, thus facilitating subsequent precipitation. After treatment with laccase, the bulk of mono- and dichlorophenol is coprecipitated with the liquors from the C and E bleaching stages. Fungi (representatives of the genera Aspergillus and Penicillium) achieved an appreciable level of degradation of chlorophenols and other chloroorganic compounds from the bleaching effluent.


2006 ◽  
Vol 6 (3) ◽  
pp. 53-61 ◽  
Author(s):  
P. Zhang ◽  
L. Jian

Ozone-enhanced photocatalytic degradation of macromolecular natural organic matter (NOM) in drinking water source was investigated. The influences of ozone dosage, retention time and bicarbonate concentration on the NOM degradation rate were studied. The change of molecular weight distribution of NOM caused by ozone-enhanced photocatalysis was analysed, as well as the degradation rate of NOM with different molecular weight (MW). It was shown that ozone-enhanced photocatalysis was much better for NOM degradation than sole ozonation or photocatalysis. Increase of both ozone dosage and retention time could effectively increase the TOC removal rate, while biodegradability could be improved solely by an increase in ozone dosage. The existence of bicarbonate significantly reduced the photocatalytic degradation rate of NOM; however, its impact was effectively offset by the addition of ozone into the photocatalytic process. Macromolecular NOM was transformed into smaller molecules, and the larger NOM was mineralized by ozone-enhanced photocatalysis much faster than the smaller NOM.


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