Fouling of ultrafiltration membranes by organic matter generated by four marine algal species

Author(s):  
Nirajan Dhakal
2018 ◽  
Vol 555 ◽  
pp. 418-428 ◽  
Author(s):  
Nirajan Dhakal ◽  
Sergio G. Salinas-Rodriguez ◽  
Alaa Ouda ◽  
Jan C. Schippers ◽  
Maria D. Kennedy

Author(s):  
KARPAKAVALLI MEENAKSHISUNDARAM ◽  
PRAKASH GOVINDARAJ ◽  
SIVASUBRAMANIAM P. ◽  
RANJITHKUMAR DHANARAJ ◽  
MOHAN SELLAPPAN

Objective: Algae is the undisputed treasures of the sea and are a valuable raw material, providing unlimited opportunities for new drug discoveries. Marine algal products are in demand in the international market in the form of standardized algal extracts or semi-finished products. Methods: Aqueous and methanolic extracts of Oedogonium globosum and Oedogonium intermedium species were obtained maceration and hot percolation. The active principles from O. intermedium were isolated, purified by column chromatography, and characterized by spectral studies IR, λmax, 1HNMR and MS. The extracts of Oedogonium species were screened for their anti-microbial effects, acute dermal irritation and wound-healing activity studies. Results: Comparing to Oedogonium intermedium (45 %, 90 %, 87 %), very low extractive yields were obtained for Oedogonium globosum (10.80 %, 37 %, 28 %). At phytochemical screening, Terpenoids, Flavanoids and, Glycans were found to be present in a significant amount and upon their isolation, it was found that a collection of fractions from cold extract with Rf value in the range 0.32-0.34 as Glycans and those from the hot extract with 0.40-0.72 as Flavanoids and those from methanolic extracts with 0.23, 0.44 and 0.71 as for Terpenoids. Anti-bacterial study revealed out the fact of Oedogonium species could give higher inhibition to gram-positive than for gram-negative bacteria at (10 μg/10μl/disc) concentration. No symptoms of systemic toxicity and mortality were observed. Silver sulfadiazine, more potent in wound closure, the effect of methanolic extracts of O. intermedium (87 %) was almost at par to the standard (95 %) in action and significantly greater than O. globosum (72 %, P<0.05). Conclusion: Admittedly, Oedogonium type algal species can be known as medicinal algae with a plethora of a wide range of pharmacological activities. Thus, this research work may be considered further for extensive innovative discoveries of new lead molecules and any other pharmacological activities, in the future.


2010 ◽  
Vol 5 (4) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Gerald Blunden ◽  
Peter F. Morse ◽  
Imre Mathe ◽  
Judit Hohmann ◽  
Alan T. Critchley ◽  
...  

Ascophyllum nodosum, and to a lesser extent, Laminaria digitata, L. hyperborea and Fucus serratus, are marine algal species utilized in the commercial production of seaweed extracts used in agriculture. Betaines have been shown to be important constituents of these extracts, but there appears to have been no study made on whether there are variations in the betaine contents of these species based on either the place or date of collection. Samples of each of the four species were collected from widely separated areas at different times of the year. Also, in the case of A. nodosum, approximately monthly collections were made from one location. The betaines detected in the various collections of the same species showed little variation, although in the case of A. nodosum, glycinebetaine was found as a minor constituent in some samples, but was not detected in others. Trigonelline was found in all the tested samples of the two Laminaria species; this is, to our knowledge, the first record of this betaine in marine algae. With the exception of trigonelline in the Laminaria species, the betaine yields from the various samples of L. digitata, L. hyperborea and F. serratus showed little variation, regardless of either the place or date of collection. The trigonelline contents of the Laminaria species collected at one location (Finavarra, Ireland), in particular of L. hyperborea, was substantially greater than those from the other places of collection. In the case of A. nodosum, the betaine yields from samples collected at one site (Dale, Pembrokeshire, UK) were significantly higher than those from the other places of collection, which were very similar to each other. There was no clear indication of seasonal variation in betaine yields from A. nodosum.


2019 ◽  
Vol 193 (2) ◽  
pp. 131-142
Author(s):  
Verónica Díaz-Villanueva

Forest streams receive large amounts of leaves whose leachates are an important source of dissolved organic matter (DOM), providing not only carbon but also organic nutrients to the microbial communities in streams. I carried out a field study to evaluate the effect of different DOM concentrations on the biofilm structure and functional traits in two similar forest streams belonging to the same catchment. I compared biofilm biomass and nutri- ent content throughout one year, algal species composition, and biofilm community-level physiological profiles in two streams with different DOM concentration and aromaticity. Dissolved nutrient concentrations were higher in the stream with higher DOM concentration, with a concomitant higher biofilm biomass, and there was also a temporal pattern, with higher values during the autumn. Phosphorus content in biofilms was also higher in the high DOM stream, coincidently with a higher capacity of the community to utilize organic P source (glucose-1-P) as a substrate. In contrast, the biofilms from the stream with lower DOM concentrations preferentially used N-organic substrates (amino acids and amines). These results reveal that the biofilms of forest streams make use of organic matter nutrients, so that streams with different DOM loads may differ in biofilm biomass due to changes in both bacterial and autotrophic biomass. In addition, biofilm dynamics may be related to forest phenology, as the highest OM input in this deciduous forest is represented by tree leaves, which supply DOM through leachates, and in particular, with P-rich leachates. In conclusion, different DOM concentrations in two nearby streams led to differences in the community-level physiological profile, as has been previously demonstrated at larger spatial scales in oceans, lakes and along larger rivers.


2011 ◽  
Vol 63 (6) ◽  
pp. 1111-1120 ◽  
Author(s):  
Y. Y. Wei ◽  
Y. Liu ◽  
R. H. Dai ◽  
X. Liu ◽  
J. J. Wu ◽  
...  

Bromide and algal pollution are important factors influencing disinfection byproduct (DBP) formation and speciation in reservoir water in coastal areas. In this study, the chlorination of model algal cellular compounds (bovine serum albumin, fish oil and starch), Microcystis aeruginosa and its extra-cellular organic matter (EOM) were conducted in the absence and presence of bromide. The main aim of the present study is to explore their potential as precursors for trihalomethanes (THMs) and haloacetic acid (HAAs) speciation upon chlorination in the presence of bromide. The results showed that all brominated THMs species were generated, whereas only bromochloroacetic acid (BCAA) or/and dibromoacetic acid (DBAA) was/were produced as for brominated HAAs (Br-HAAs) from the three model compounds in the presence of bromide. The effect of bromide on Br-HAAs speciation upon fish oil chlorination was more evident than with BSA and starch. There was a good correlation between the species predicted from the model compounds and those obtained from specific algal species. Br-HAAs and Br-THMs species from Microcystis aeruginosa cells or EOM were the same as those from bovine serum albumin in the presence of bromide.


2011 ◽  
Vol 11 (6) ◽  
pp. 668-674 ◽  
Author(s):  
B. Q. Zhao ◽  
C. P. Huang ◽  
S. Y. Chen ◽  
D. S. Wang ◽  
T. Li ◽  
...  

Natural organic matter (NOM) plays a significant role in the fouling of ultrafiltration membranes in drinking water treatment processes. For a better understanding of the interaction between fractional components of NOM and polysulfone (PS) ultrafiltration membranes used for drinking water treatment, fouling and especially the physically irreversible fouling of natural organic matter were investigated. Resin fractionation, fluorescence excitation–emission matrix (EEM) spectroscopy, fourier transform infrared spectroscopy (FTIR), contact angle and a scanning electron microscope (SEM) were employed to identify the potential foulants. The results showed that humic acid and fulvic acid of small size were likely to permeate the membrane, while the hydrophobic fraction of humic and fulvic acid and aromatic proteins tended to be rejected and retained. Organic compounds such as proteins, humic substances, and polysaccharide-like materials, were all detected in the fouling layer. The physically irreversible fouling of the PS membrane seemed to be mainly attributed to the hydrophobic fraction of humic substances.


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