scholarly journals Effects of micro-flocculation pretreatment on the ultrafiltration membrane fouling caused by different dissolved organic matters in treated wastewater

2021 ◽  
Author(s):  
Lanxin Ren ◽  
Chen Liu ◽  
Ting Meng ◽  
Yingxue Sun
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Fulvic Acid ◽  
Sodium Alginate ◽  
Membrane Fouling ◽  
Treated Wastewater ◽  
Organic Matters ◽  
Dissolved Organic Matters ◽  
Cake Layer ◽  
Hydrophilic Organic Matter

Abstract This study investigated the efficacy of using micro-flocculation as a pretreatment approach in alleviating ultrafiltration (UF) membrane fouling caused by organic matters in treated wastewater. Three typical model dissolved organic matters (DOM), humic acid, fulvic acid, and sodium alginate, were employed to simulate membrane fouling. The results showed that micro-flocculation using poly aluminum chloride (PAC) or polymerized ferric sulfate (PFS) as flocculant could effectively enhance the treatment performance of UF process on DOM. With 6 mg/L PAC, the removal efficiency of humic acid, fulvic acid, and sodium alginate by micro-flocculation combined UF process reached 79.95%, 63.25%, and 51.14%, respectively. Specifically, after micro-flocculation, micromolecular hydrophilic organic matter (e.g., fulvic acid) tended to form a compact cake layer. The macromolecular hydrophobic organic matter (e.g., humic acid) and macromolecular hydrophilic organic matter (e.g., sodium alginate) generally led to a loose cake layer. At PAC dosage of 6 mg/L, the membrane specific flux (J/J0) at the end was improved by 11.71%, 10.27%, and 2.2% for humic acid, sodium alginate and fulvic acid solutions, respectively, compared with UF process alone. It could be inferred that micro-flocculation pretreatment can effectively mitigate the membrane fouling when treating wastewater containing humic acid, sodium alginate, or fulvic acid.

scholarly journals The Function of Adsorption, Photo-Oxidation, and Humic Acid Using Air Backwashing in Integrated Water Treatment of Multichannel Ceramic MF and PP Particles

Membranes ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 28
Author(s):  
Sangwoo Park ◽  
Dongyeop Kim ◽  
Jin Yong Park
Keyword(s):  
Humic Acid ◽  
Water Treatment ◽  
Uv Radiation ◽  
Membrane Fouling ◽  
Fouling Resistance ◽  
Organic Matters ◽  
Photo Oxidation ◽  
Dissolved Organic Matters ◽  
Treatment Function

For advanced water treatment, function of microfiltration (MF), adsorption, photo-oxidation, humic acid (HA), and polypropylene (PP) particles on membrane fouling and decay effectiveness were investigated in an integrated water treatment, of multichannel ceramic MF and PP particles, using UV radiation and air backwashing. The synthetic feed was organized with HA and kaolin. The membrane fouling resistance (Rf) of the (MF + PP) system presented the lowermost, and amplified intensely from the (MF + UV) to MF system. The percentages of MF and adsorption by PP particles for turbidity treatment were 87.6% and 3.8%, individually; however, the percentages of MF and adsorption by PP particles for dissolved organic matters (DOM) treatment were 27.9% and 5.0%, respectively. The decay effectiveness of turbidity presented the greatest 95.4% at HA of 10 mg/L; however, that of DOM increased as HA concentration ascended. The ultimate Rf after 180 min procedure showed the maximum at 30 g/L of PP particles concentration, and improved dramatically, as PP particles decreased. Finally, the maximum VT was acquired at 30 and 50 g/L of PP particles, because flux preserved greater throughout the procedure. The decay effectiveness of turbidity and DOM showed the maximal 95.4% and 56.8% at 40 and 50 g/L of PP particles, respectively.

scholarly journals Removal characteristics of dissolved organic matter and membrane fouling in ultrafiltration and reverse osmosis membrane combine processes treating the secondary effluent of wastewater treatment plant

2020 ◽  
Author(s):  
Jianwei Liu ◽  
Mengfei Zhao ◽  
Cui Duan ◽  
Peng Yue ◽  
Tinggang Li
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Humic Acid ◽  
Fulvic Acid ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Ro Membrane

Abstract The widespread implementation of municipal wastewater treatment and reuse must first ensure the safety of reused wastewater. The effluent of the municipal wastewater treatment plant contains a large amount of dissolved organic matter (DOM), which adversely affects the reuse of wastewater. In this study, the ultrafiltration (UF) + reverse osmosis (RO) process was used to treat the effluent from wastewater treatment plants. The relationship between the removal performance, membrane fouling of the UF + RO process, and DOM characteristics of influent were studied. The results show that DOM can be removed effectively by UF + RO process. The UF mainly removes DOM with a molecular weight greater than 10 kDa, while RO has a significant removal effect on low-molecular DOM, which mainly cause UF and RO membrane fouling. The UF + RO process has a significant removal rate on fulvic acid, humic acid, tyrosine, and tryptophan, and the order is humic acid > fulvic acid > tyrosine > tryptophan. Fulvic acid contributed the most to the UF membrane fouling, while fulvic acid and protein-like proteins contributed mainly to the RO membrane fouling.

scholarly journals Proof of Concept for Light Conducting Membrane Substrate for UV-Activated Photocatalysis as an Alternative to Chemical Cleaning

Membranes ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 122 ◽  
Author(s):  
Lavern Nyamutswa ◽  
Bo Zhu ◽  
Dimuth Navaratna ◽  
Stephen Collins ◽  
Mikel Duke
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Current Method ◽  
Dip Coating ◽  
Polluted Water ◽  
Chemical Cleaning ◽  
Cake Layer

Adopting an effective strategy to control fouling is a necessary requirement for all membrane processes used in the water/wastewater treatment industry to operate sustainably. The use of ultraviolet (UV) activated photocatalysis has been shown to be effective in mitigating ceramic membrane fouling by natural organic matter. The widely used configuration in which light is directed through the polluted water to the membrane’s active layer suffers from inefficiencies brought about by light absorption by the pollutants and light shielding by the cake layer. To address these limitations, directing light through the substrate, instead of through polluted water, was studied. A UV conducting membrane was prepared by dip coating TiO2 onto a sintered glass substrate. The substrate could successfully conduct UV from a lamp source, unlike a typical alumina substrate. The prepared membrane was applied in the filtration of a humic acid solution as a model compound to study natural organic matter membrane fouling. Directing UV through the substrate showed only a 1 percentage point decline in the effectiveness of the cleaning method over two cleaning events from 72% to 71%, while directing UV over the photocatalytic layer had a 9 percentage point decline from 84% to 75%. Adapting the UV-through-substrate configuration could be more useful in maintaining membrane functionality during humic acid filtration than the current method being used.

scholarly journals Ultrafiltration fouling behavior of natural organic matter: a perspective of EEM and molecular weight distribution

2021 ◽  
Author(s):  
Gao Kuo ◽  
Song Yuan
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Humic Acid ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Microbial Product ◽  
Membrane Morphology ◽  
Atomic Force ◽  
Fluorescence Characteristics ◽  
Cake Layer

Abstract As the natural organic matter (NOM) can cause serious ultrafiltration (UF) membrane fouling, most previous studies on UF fouling caused by NOM focused on the contribution of NOM characteristics. In this study, the correlation of molecular weight and fluorescence characteristics was examined and the fouling behavior of NOM were examined in a comprehensive manner through a lot of analysis including the redundancy analysis (RDA), parallel factor analysis (PARAFAC) and atomic force microscope (AFM). The results showed that NOM from Tong Xin river was composed of humic acid (500 Da–8,000 Da), tryptophan-like substance, soluble microbial product (SMP) and aromatic protein (600,000 Da–2,000,000 Da).Notably, UF performance was significantly affected by the humic acid-like substance. Concurrently, the combined mechanism (CM) model was adopted to evaluate the fouling mechanism of NOM. The results indicated that cake-intermediate model played an important part during membrane fouling and the cake layer fouling had a larger predominance over the intermediate blocking which can be further proved in the membrane morphology detection.

Characteristics of fouling due to clay-organic substances in potable water treatment by ultrafiltration

1996 ◽  
Vol 34 (9) ◽  
pp. 157-164 ◽  
Author(s):  
Kim C.-H. ◽  
M. Hosomi ◽  
A. Murakami ◽  
M. Okada
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Humic Acid ◽  
Fulvic Acid ◽  
Size Distribution ◽  
Ultrafiltration Membrane ◽  
Organic Substances ◽  
Decomposition Products ◽  
Microbial Decomposition ◽  
Fouling Materials

Effects of clay on fouling due to organic substances and clay were evaluated by model fouling materials and kaolin. Model fouling materials selected were protein, polysaccharide, fulvic acid, humic acid and algogenic matter (EOM:ectracellular organic matter, microbial decomposition products) and kaolin was selected as the clay material. Polysulfone membrane (MWCO(Molecular Weight Cut-Off) 10,000, 50,000 and 200,000) was used as an ultrafiltration membrane. In particular, the flux measurement of solutions containing algogenic matter used an ultrafiltration membrane of MWCO 50,000. The flux of protein and polysaccharide with coexistence of kaolin increased in the case of the ratio of MW/MWCO being greater than one, but did not increase in the case of the MW/MWCO ratio being below one. In contrast, the flux of fulvic acid and humic acid with coextence of kaolin decreased regardless of the ratio of MW/MWCO. The addition of dispersion agent and coagulant in the organic substances and kaolin mixture solution changed the size distribution of kaolin, and resulted in a change of the flux. EOM and microbial decomposition products decreased with the increase of the fraction of organic matter having molecular weight more than MWCO of membrane. The flux of the algogenic organic matter with coexistence of kaolin decreased with the increase of the amount of kaolin. It was suggested that the decline of the flux with coexistence of kaolin was due to the change of the resistance of the kaolin cake layer corresponding to the change in kaolin size distribution with charge.

HUMUS FRACTION RATIOS AS A MEANS OF DISCRIMINATING BETWEEN HORIZON TYPES

1980 ◽  
Vol 60 (2) ◽  
pp. 219-229 ◽  
Author(s):  
L. E. LOWE
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Carbon Content ◽  
Fulvic Acid ◽  
Soil Classification ◽  
Acid Fraction ◽  
Humus Fraction ◽  
Wide Range ◽  
Fraction Distribution

Humus fraction distribution in a wide range of horizon samples was examined by measuring carbon content in humic acid (Ch), in fulvic acid (Cf) and in the strongly colored polyphenolic component of the fulvic acid fraction (Ca). Fraction distribution was described by the ratios Ch/Cf and Ca/Cf. It was concluded that humus fraction ratios were related to horizon types as used in the Canadian System of Soil Classification, and were effective in discriminating between certain horizon types, particularly between Luvisolic Bt and Podzolic Bf. The results also suggested that humus fraction ratios may be effective in separating distinct sub-populations within Ah horizons and Bf horizons in general, based on qualitative differences in organic matter present. Aspects of the role of humus fractions in soil genesis are discussed.

Identification of humic acid-like and fulvic acid-like natural organic matter in river water using fluorescence spectroscopy

2011 ◽  
Vol 63 (10) ◽  
pp. 2427-2433 ◽  
Author(s):  
R. H. Peiris ◽  
H. Budman ◽  
C. Moresoli ◽  
R. L. Legge
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Water Sample ◽  
Fulvic Acid ◽  
River Water ◽  
Natural Organic Matter ◽  
Drinking Water Treatment ◽  
Fluorescence Analysis ◽  
Product Formation ◽  
Fluorescence Excitation

Identifying the extent of humic acid (HA)-like and fulvic acid (FA)-like natural organic matter (NOM) present in natural water is important to assess disinfection by-product formation and fouling potential during drinking water treatment applications. However, the unique fluorescence properties related to HA-like NOM is masked by the fluorescence signals of the more abundant FA-like NOM. For this reason, it is not possible to accurately characterize HA-like and FA-like NOM components in a single water sample using direct fluorescence EEM analysis. A relatively simple approach is described here that demonstrates the feasibility of using a fluorescence excitation-emission matrix (EEM) approach for identifying HA-like and FA-like NOM fractions in water when used in combination with a series of pH adjustments and filtration steps. It is demonstrated that the fluorescence EEMs of HA-like and FA-like NOM fractions from the river water sample possessed different spectral properties. Fractionation of HA-like and FA-like NOM prior to fluorescence analysis is therefore proposed as a more reasonable approach.

Genesis of podzols on coastal dunes in southern Queensland .III. The role of aluminum organic complexes in profile development

Soil Research ◽  
1992 ◽  
Vol 30 (5) ◽  
pp. 645 ◽  
Author(s):  
JO Skjemstad
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Organic Acids ◽  
Fulvic Acid ◽  
Matrix Material ◽  
Chemical Properties ◽  
Coastal Dunes ◽  
Total Carbon ◽  
Aluminium Content ◽  
Carboxyl Content

Organic matter was extracted sequentially with 0.1 M HC1, 0.5 M HCl and 0.5 M NaOH from three soil samples consisting of the dark brown organic nodules and matrix material from the Bhs2 horizon and the untreated Bhs3 horizon material of a freely drained podzol from Cooloola. The NaOH extract was further divided into fulvic and humic acid. After extracts were separated on G-50 Sephadex gel, titration data demonstrated that carboxyl groups in the collected fractions ranged from 8.8% to 61.3% of the total carbon although some overestimate of the carboxyl content may result from the chromic acid method used. Fractions excluded by the gel made up >95% of each extract and the first fraction collected in each case was the lowest in carboxyl content. These fractions from the 0-1 M HC1 extracts were generally low in carboxyl content (8.8%-24.9%) as were those from the humic acids (10.7-11.2%) although the major remaining humic acid fractions were extremely high (58.6-61.3510). The 0.5 M HCl and fulvic acid extracts appeared similar in chemical properties with carboxyl content of the separated fractions ranging from 16.4 to 44.0%. Molar absorptivities were in the order 0.1 M HCl < 0.5 M HC1< fulvic acid < humic acid. The pKa values of the acids were found to increase in the order humic acid < fulvic acid = 0.5 M HCl < 0.1 M HCl as well as in the order Bhs2 (dark brown nodules) < Bhs2 (yellow brown bulk) < Bhs3 for each fraction. Ease of flocculation of the extracts by aluminium counter ions decreased in the order humic acid > fulvic acid > 0.5 M HCl > 0.1 M HCl. It was demonstrated that other organic extracts low in aluminium content could be used to remobilize flocculated humic acid through redistribution of the aluminium bound to the precipitated phase into the solution phase. From these and other data, a hypothesis explaining the specific manner in which organic matter is arrested during podzolization is proposed. Some major factors appear to be (a) the pH of the horizon, (6) pKa and aromaticity of the organic acids and (c) availability of aluminium to the organic fractions. Remobilization of precipitated organic matter requires the presence of organic acids of low aluminium content in the percolating soil solution. This hypothesis adequately describes the process by which distinct Bh, Bhs and Bs horizons are formed and evolve during profile genesis.

HUMIC-FULVIC ACID RELATIONSHIPS IN ORGANIC SOILS AND HUMIFICATION OF THE ORGANIC MATTER IN THESE SOILS

1967 ◽  
Vol 47 (3) ◽  
pp. 245-250 ◽  
Author(s):  
M. Schnitzer
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Humic Acid ◽  
Fulvic Acid ◽  
Oxidative Degradation ◽  
Fulvic Acids ◽  
Organic Soil ◽  
Organic Soils ◽  
Salting Out ◽  
Naoh Solution

Twenty organic-soil samples of widely differing degrees of decomposition were extracted with 0.5 N NaOH solution under N2. Amounts of humic and of fulvic acids in the acidified extracts did not correlate significantly with pyrophosphate solubilities. This was thought to be due to interference in the separation scheme by relatively large amounts of ash constituents in the extracts. Since the "classical" fractionation of soil organic matter appears to involve essentially the "salting out" of higher molecular-weight humic from lower molecular-weight fulvic acids, an excessively high salt concentration during the separation should be avoided.To lower the concentration of inorganic constituents in the extracts, the samples were first pretreated with dilute HCl–HF solution and then extracted with 0.1 N NaOH rather than with 0.5 N NaOH. Under these conditions, amounts of fulvic acids in the acidified extracts showed a significant positive correlation (r = 0.52) with pyrophosphate solubilities of untreated extracts, whereas amounts of humic acids in the extracts exhibited a highly negative correlation (r = −0.57) with pyrophosphate solubilities. In the soils examined, increased humification was associated with increases in fulvic-acid but decreases in humic-acid concentrations.From the results of this and of earlier investigations done in this laboratory it appeared that the main mechanism governing humification in these soils was oxidative degradation, resulting ultimately in the formation of fulvic from humic acid.

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