Seaweed Waste Research Articles

Efficient Isolation of Cellulose Nanocrystals from Seaweed Waste via a Radiation Process and Their Conversion to Porous Nanocarbon for Energy Storage System.

This article presents an efficient method for isolating cellulose nanocrystals (CNcs) from seaweed waste using a combination of electron beam (E-beam) irradiation and acid hydrolysis. This approach not only reduces the chemical consumption and processing time, but also improves the crystallinity and yield of the CNcs. The isolated CNcs were then thermally annealed at 800 and 1000 °C to produce porous nanocarbon materials, which were characterized using scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy to assess their structural and chemical properties. Electrochemical testing of electrical double-layer capacitors demonstrated that nanocarbon materials derived from seaweed waste-derived CNcs annealed at 1000 exhibited superior capacitance and stability. This performance is attributed to the formation of a highly ordered graphitic structure with a mesoporous architecture, which facilitates efficient ion transport and enhanced electrolyte accessibility. These findings underscore the potential of seaweed waste-derived nanocarbon as a sustainable and high-performance material for energy storage applications, offering a promising alternative to conventional carbon sources.

Value-added utilization technologies for seaweed processing waste in a circular economy: Developing a sustainable modern seaweed industry.

The global seaweed industry annually consumes approximately 600,000 tons of dried algal biomass to produce algal hydrocolloids, yet only 15-30% of this biomass is utilized, with the remaining 70-85% discarded or released as scum or wastewater during the hydrocolloid extraction process. This residual biomass is often treated as waste and not considered for further commercial use, which contradicts the principles of sustainable development. In reality, the residual algal biomass could be employed to extract additional biochemical components, such as pigments, proteins, and cellulose, and these ingredients have important application prospects in the food sector. According to the biorefinery concept, recycling various products alongside the principal product enhances overall biomass utilization. Transitioning from traditional single-product processes to multi-product biorefineries, however, raises operating costs, presenting a significant challenge. Alternatively, developing value-added utilization technologies that target seaweed waste without altering existing processes is gaining traction among industry practitioners. Current advancements include methods such as separation and extraction of residual biomass, anaerobic digestion, thermochemical conversion, enzymatic treatment, functionalized modification of algal scum, and efficient utilization through metabolic engineering. These technologies hold promise for converting seaweed waste into alternative proteins, dietary supplements, and bioplastics for food packaging. Combining multiple technologies may offer the most effective strategy for future seaweed waste treatment. Nonetheless, most research on value-added waste utilization remains at the laboratory scale, necessitating further investigation at pilot and commercial scales.

Nitrogen conversion performance of a polypropylene carrier designed to promote biofilm formation through foaming

The performance of plastic carriers in a moving bed biofilm reactor used for water treatment is strongly determined by the carrier material and its shape. Only a few reports have described the effect of foaming on biofilm formation and nitrogen conversion by polypropylene (PP) carriers. Here, we investigated a PP foam carrier for its biofilm forming ability and the resulting biofilm’s ability to remove nitrogen compounds. The results revealed that foaming increased the amounts of denitrifying bacterial biofilms attached to PP by approximately 44 times, indicating that unevenness by foaming promoted biofilm formation. Biofilms were also formed using activated sludges from nitrification and denitrification of a wastewater treatment facility. Amplicon sequencing analysis of the biofilms revealed that the families Xanthomonadaceae and Comamonadaceae, including nitrifying bacteria, were enriched in nitrifying sludge-derived biofilms, whereas Dechloromonas sp. and family Pseudomonadaceae, including denitrifying bacteria, were enriched in denitrifying sludge-derived biofilms. Furthermore, nitrifying sludge-derived biofilms completely removed ammonia, and its removal ability was superior to that of the original sludge. Denitrification by denitrifying sludge-derived biofilms was promoted by the addition of fumaric acid. Both nitrifying and denitrifying sludge-derived biofilms could remove nitrogen compounds from 1.4 mM ammonia-containing synthetic wastewater. Finally, the effect of biomass addition on the carrier was investigated. The addition of composted seaweed waste to PP foam carriers enhanced the formation of denitrifying sludge-derived biofilms by approximately 2.2 times, and the denitrification reaction by biofilms was promoted. These results revealed that waste biomass can be used to further enhance PP foam carrier performance.

Highly crystalline cellulose microparticles from dealginated seaweed waste ameliorate high fat-sugar diet-induced hyperlipidemia in mice by modulating gut microbiota

The effects of seaweed cellulose (SC) on high fat-sugar diet (HFSD)-induced glucolipid metabolism disorders in mice and potential mechanisms were investigated. SC was isolated from dealginated residues of giant kelp (Macrocystis pyrifera), with a crystallinity index of 85.51 % and an average particle size of 678.2 nm. Administering SC to C57BL/6 mice at 250 or 500 mg/kg BW/day via intragastric gavage for six weeks apparently inhibited the development of HFSD-induced obesity, dyslipidemia, insulin resistance, oxidative stress and liver damage. Notably, SC intervention partially restored the structure and composition of the gut microbiota altered by the HFSD, substantially lowering the Firmicutes to Bacteroidetes ratio, and greatly increasing the relative abundance of Lactobacillus, Bifidobacterium, Oscillospira, Bacteroides and Akkermansia, which contributed to improved short-chain fatty acid (SCFA) production. Supplementing with a higher dose of SC led to more significant increases in total SCFA (67.57 %), acetate (64.56 %), propionate (73.52 %) and butyrate (66.23 %) concentrations in the rectal contents of HFSD-fed mice. The results indicated that highly crystalline SC microparticles could modulate gut microbiota dysbiosis and ameliorate HFSD-induced obesity and related metabolic syndrome in mice. Furthermore, particle size might have crucial impact on the prebiotic effects of cellulose as insoluble dietary fiber.

Cystoseira myrica: from beach-cast seaweed to fucoidan with antioxidant and anticoagulant capacity

This study highlights the potential of the brown algae Cystoseira myrica, collected from raw beach seaweed wastes, as a reliable source of bioactive fucoidan. Fucoidans are natural bioactive sulfated polysaccharides that are gaining popularity worldwide due to their diverse biochemical composition, attractive physical properties, and functional pharmacological activities. The aim of this work is to valorize the beach-Accumulated brown algae C. myrica by fucoidan extraction and to investigate its anticoagulant and antioxidant activity. Fucoidan was extracted using several steps of papain digestion followed by cetyltrimethylammonium bromide (CTAB) precipitation and calcium chloride treatment to avoid the coextraction of other polysaccharides. Structural features of the extracted fucoidan were investigated by Fourier transform infrared spectroscopy (FT-IR), solid-state nuclear magnetic resonance (NMR) and high-resolution mass spectroscopy. Agarose gel electrophoresis was used to confirm the purity of the isolated fucoidan from C. myrica. Anticoagulant properties were studied in vitro by activated partial thromboplastin time (aPTT) and prothrombin time (PT) assays. Furthermore, the antioxidant activity was investigated by 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and Fe chelating ability. Our results indicate that the approach used was effective in extracting fucoidan with a yield of 3.07%, a high amount of sulfate (27.79%), and fucose was found to be the major monosaccharide component. The extracted fucoidan showed an interesting anticoagulant activity. It prolonged aPTT significantly at a concentration of 10 µg/ml and prolonged PT at high doses. This demonstrated that fucoidan from C. myrica may affect intrinsic pathways while having little impact on the extrinsic mechanism of coagulation. However, the extracted fucoidan significantly exhibited an interesting antioxidant capacity as shown by the higher ABTS radical scavenging activity and Ferrous ion-chelating effect. The current findings suggest that fucoidan isolated from C. myrica has unique structural, antioxidant and anticoagulant properties and offers innovative therapeutic possibilities.

Investigation of Blended Seaweed Waste Recycling Using Black Soldier Fly Larvae

Seaweed waste is often found in the coastal areas of Indonesia. Along with other waste, large quantities of seaweed will disrupt the ecosystem and harm the surrounding environment. Therefore, treating seaweed waste effectively and efficiently is necessary to mitigate such adverse effects. This study processed seaweed waste using Black Soldier Fly (BSF) larvae to accelerate waste degradation, reducing the waste buildup. The characteristics of waste, the feeding treatment, chemical content, and parameters of waste processing were assessed. Based on the results, seaweed waste contains highly organic compounds, potentially used as fertilizer or animal feed. The feeding method demonstrated that the mass of BSF larvae increased according to the intensity of the feeding treatment. The total waste degradation obtained from the BSF larvae was 72.61% with a waste reduction index of 1.87 g/day, and the efficiency of digested feed was 7.61% with feeding treatment every three days. The chemical composition of BSF pre-pupae, pupae, and residues was also evaluated to determine their feasibility as animal feed and biomass. The results suggested that pre-pupae and pupae comprise protein, fat, calcium, and phosphorus. At the same time, the waste residue has a C-organic and N-organic ratio of 13%–14% and is an alternative for future waste-to-energy applications. Overall, BSF offers a great prospect in generating high-value products and simultaneously serves as a strategy for efficient waste management.

Seaweed Waste in Nusa Dua: An Analysis of Environmental Challenges and Recycling Opportunities

Nusa Dua, a prominent tourist destination, grapples with the multifaceted challenge of seaweed waste accumulation. Through a qualitative approach anchored in extensive literature review and observational data, this study delves into the environmental implications and the latent opportunities that seaweed waste presents. The research reveals significant potential repercussions ranging from ecological disturbances to potential economic downturns linked to reduced tourist appeal. However, it also uncovers various recycling possibilities, including biofuel production and sustainable packaging, offering viable solutions to the problem. This paper underscores the necessity of collaborative action, innovative policies, and community engagement to transform Nusa Dua's seaweed waste challenge from an environmental concern into an opportunity for sustainable development.

Microwave Assisted Extraction of Raw Alginate as a Sustainable and Cost-Effective Method to Treat Beach-Accumulated Sargassum Algae.

This paper highlights the potential of Sargassum algae, recovered from raw beach seaweed wastes, as a valid source of valuable sodium alginate. Alginate is a biodegradable, highly attractive polysaccharide widely used in food, pharmaceuticals, and biomedicine applications. The aim of this work is to employ a new eco-sustainable and cost-effective extractive method to obtain alginate as a raw material from pollutant organic Sargassum seaweeds. Algae were exposed to microwave pre-treatment under static and dynamic conditions, and three different extractive protocols were followed: (a) conventional, (b) hot water and (c) alkaline method. All samples were characterized by GPC, SEM, FTIR/ATR and TGA. It was found that alginate's best performances were obtained by the microwave dynamic pre-treatment method followed by alkaline extractive protocol. Nevertheless, the microwave pre-treatment of algae allowed the easiest breaking of their cell walls and the following fast releasing of sodium alginate. The authors demonstrated that microwave-enhanced extraction is an effective way to obtain sodium alginate from Sargassum-stranded seaweed waste materials in a cost-effective and eco-sustainable approach. They also assessed their applications as mulching films for agricultural applications.

Integrated approach for enhanced crude bio-oil yield from microalgae cultivated on the aqueous phase of hydrothermal co-liquefaction with agar-free seaweed residues

The present study evaluated the efficiency of microalgae cultivation on the aqueous phase (Aq-LP) produced from (Co-)hydrothermal liquefaction (HTL) of agar-free seaweed waste. Optimization of bio-oil production from Co-HTL of seaweed residue with the studied microalgal biomass grown in Bold's Basal Medium (BBM) was initially carried out using Box-Behnken model. The highest bio-oil yield of 42.21% was recorded by HTL of microalgal biomass at 250 °C for 60 min, which showed insignificant difference with that from Co-HTL. Comparatively, Aq-LP from microalgal biomass showed the highest organic load with total organic carbon of 11.69 g L−1, while that from seaweed residue showed the lowest value of 7.47 g L−1. However, mineral ions in the Aq-LP from seaweed residue showed higher values compared to microalgal biomass. Therefore, Co-HTL enriched the Aq-LP with nutrients from both feedstocks which resulted in 10.3% higher biomass yield than the control. The experimental bio-oil yield was 15.3% higher than the calculated value, which confirms a synergistic action during Co-HTL. In addition, the quality of the bio-oil obtained via HTL was improved after Co-HTL of both feedstocks. Results estimated that the higher biomass yield of microalgae due to cultivation in Co-HTL Aq-LP could promote the final bio-oil volumetric yield to 891 kg m−3, comparing to 819 kg m−3 using the synthetic medium.

Potent Bioactive Compounds From Seaweed Waste to Combat Cancer Through Bioinformatics Investigation.

The seaweed industries generate considerable amounts of waste that must be appropriately managed. This biomass from marine waste is a rich source of high-value bioactive compounds. Thus, this waste can be adequately utilized by recovering the compounds for therapeutic purposes. Histone deacetylases (HDACs) are key epigenetic regulators established as one of the most promising targets for cancer chemotherapy. In the present study, our objective is to find the HDAC 2 inhibitor. We performed top-down in silico methodologies to identify potential HDAC 2 inhibitors by screening compounds from edible seaweed waste. One hundred ninety-three (n = 193) compounds from edible seaweeds were initially screened and filtered with drug-likeness properties using SwissADME. After that, the filtered compounds were followed to further evaluate their binding potential with HDAC 2 protein by using Glide high throughput virtual screening (HTVS), standard precision (SP), extra precision (XP), and quantum polarized ligand docking (QPLD). One compound with higher negative binding energy was selected, and to validate the binding mode and stability of the complex, molecular dynamics (MD) simulations using Desmond were performed. The complex-binding free energy calculation was performed using molecular mechanics-generalized born surface area (MM-GBSA) calculation. Post-MD simulation analyses such as PCA, DCCM, and free energy landscape were also evaluated. The quantum mechanical and electronic properties of the potential bioactive compounds were assessed using the density functional theory (DFT) study. These findings support the use of marine resources like edible seaweed waste for cancer drug development by using its bioactive compounds. The obtained results encourage further in vitro and in vivo research. Our in silico findings show that the compound has a high binding affinity for the catalytic site of the HDAC 2 protein and has drug-likeness properties, and can be utilized in drug development against cancer.

Effect of glycerol concentration and carboxy methyl cellulose on biodegradable film characteristics of seaweed waste

Eucheuma cottonii waste seaweed has high cellulose content. Therefore, it could be potentially used as a raw material for biodegradable films to replace plastic. A plastic film is its moisture resistance, and this property allows plastic films to be used as packaging materials and biodegraded by microbes. This research aims to obtain a concentration of glycerol and Carboxy Methyl Cellulose (CMC) to obtain the best biodegradable film characteristics from E. cottonii seaweed waste. This study was conducted in factorial by using a complete randomized block design with two factors: glycerol concentration and CMC concentration. Each treatment has three levels and three replications (3 × 3). The first factor was glycerol concentration: 0.25% (G1), 0.5% (G2), and 0.75% (G3). The second factor included concentrations of 1% CMC (C1), 2% CMC (C2), and 3% CMC (C3). Then, Tensile Strength (TS), thickness, solubility, and elongation were observed. Functional group analysis was conducted by Fourier-transform infrared spectroscopy and biodegradability test. The results showed that the addition of glycerol concentrations of 0.5 and 0.7% and CMC from 1 to 3% produced tensile strengths of 23–39 MPa. These values are proportional to the tensile strength of Poly Tetra Fluoro ethyne (PTFE) and Poly Propylene (PP) synthetic plastics released by Dotmar Engineering Plastics. The biodegradability test showed that the produced biodegradable films decomposed after 14 days.

Synergetic approach for energy recovery from coastal wastes based on combination of biological and thermal treatment

ABSTRACT Marine biomass is a promising renewable energy source, especially as this waste contains a large amount of cellulose and hemicellulose, which can contribute to convert it into energy products using anaerobic digestion (AD) and pyrolysis processes. This work was focused on a synergetic view of marine coastal waste treatment (seaweed) using two different technologies, anaerobic microbiological co-digestion, and pyrolysis. The experiments were performed with two merged technologies to assess the captured energy from the digestate in case it is contaminated. Anaerobic co-digestion was conducted using a periodic load laboratory bench with a vertical biogas digester. An evaluation of possible product yields and composition during pyrolysis at a laboratory-scale bench has been performed. The products obtained after the thermal treatment analyzed using an online gas measurement system and gas chromatographs Agilent 7890A with TCD detector (for gases) and Agilent 7890A with MS detector (for liquids). The results demonstrated that biogas yield was 174.1 l/kg (DM). Seaweed washed by seawater yields a higher amount of biogas (202.5 l/kg). Meanwhile, seaweed, sewage sludge, and digestate samples subjected to thermal treatment produced 17%, 30%, and 15% of liquids products, respectively. The economic performance assessment showed that the application of the developed merged approach on an industrial scale could provide an economic return of up to 8.3 $/100 kg of waste. Based on that, merged AD and pyrolysis technologies could be adapted as a promising technology to valorize seaweed wastes and utilize them as a new sustainable source for renewable energy.

Valorization and upgrading of the nutritional value of seaweed and seaweed waste using the marine fungi Paradendryphiella salina to produce mycoprotein

In this work, we have valued and increased the nutritional value of Macrocystis pyrifera and seaweed waste from brown macroalgae through a submerged fermentation process with the marine fungus Paradendryphiella salina. The product resulting after fermentation, the mycelium of P. salina together with the hydrolyzed algal, is called mycoprotein. We analyze the nutritional composition (carbohydrates, protein, amino acids, total fibre, caloric energy, fat), phenolic compounds and antioxidant activity in vitro of the mycoprotein obtained and of the algal biomass before fermentation. The content of total protein increased ~141% in fermented M. pyrifera and the total amino acids increased 73,5%. While that in fermented seaweed waste the protein increased ~131%. Furthermore, the fermentation on M. pyrifera and seaweed wastes had a positive effect on total carbohydrate reduction of this biomass algal ~38% and 35%, respectively. The concentration of the main complex polysaccharide presents in M. pyrifera, the alginate, was decreased significantly (up to 1.5-fold). In contrast, the cellulose concentration in fermented seaweed waste was significantly lower than the unfermented seaweed (up to 2.9-fold). According to these results, fermentation seems to enhance the nutritional value of seaweed biomass, and its potential is compared with Quorn, the mycoprotein used in food. Additionally, the total compounds phenolic and the antioxidant activity of fermented seaweed biomass exhibited an increase significantly face the unfermented seaweed biomass. Fermented seaweed waste resulted in the highest value of total phenolics and higher antioxidant activity, with an increase of 180.9 and 86.3%, respectively. Finally, this work shows that P. salina can assimilate brown macroalgae and even wastes of this biomass and produce mycoprotein like a promising strategy, and that may be useful food or functional food and feed.

Upgrading end-of-line residues of the red seaweed Gelidium sesquipedale to polyhydroxyalkanoates using Halomonas boliviensis

Agar extraction from Gelidium and Gracilaria red seaweed species produces hundred thousand ton of carbohydrate-rich residues annually. Gelidium sesquipedale waste biomass obtained after agar extraction, still contained 44.2 % w/w total carbohydrates (dry-weight basis). These residues were biologically up-graded to poly-3-hydroxybutyrate (P3HB) after saccharification of their carbohydrate fraction to simple sugars. A combined hydrolysis treatment using sulfamic acid followed by enzymatic hydrolysis with cellulases produced a glucose-rich hydrolysate with a negligible content of inhibitors. With this treatment a sugar yield of circa 30 % (g glucose/g biomass) was attained. The algal hydrolysates were assessed as carbon source for the production of P3HB by the halotolerant bacteria Halomonas boliviensis. A cell concentration of 8.3 g L−1 containing 41 % (w/w) of polymer and a yield (YP/S) of 0.16 gpolymer/gglucose were attained in shake flask assays. In this work, cellulose-rich seaweed waste was shown to be an upgradable, sustainable source of carbohydrates.

CRITICAL SOIL OPTIMIZATION STRATEGY THROUGH THE UTILIZATION OF AGRICULTURAL WASTE, LIVESTOCK, AND FISHERIES

Critical land area in Indonesia was recorded 23.25 million ha in 2000, and increased to 77.8 million ha in 2007, efforts are needed to optimize it. However, the existence of agricultural waste, livestock waste and sewage abundant fishery potential to increase soil fertility has not been utilized to the maximum. This study aimed to determine the macro nutrient content available in waste after the fermentation process. This research is an experimental research conducted in a laboratory to find out the content of: N, P, K, C / N ratio. The method for making liquid organic fertilizer is fermentation for one month using EM4 effective microorganisms, then analyzed using Spectrometry and Titrimetry Kjeldahl. The results showed that the highest N content was in bio urine fermentation (0.126%), fish waste (0.035%) and mixed waste (0.028%); The highest P was found in cattle rumen (7.239 mg / L), bio urine (5.234 mg / L), and seaweed (4.689 mg / L), and highest K was found in fruit waste (7, 801 mg / L). The highest C / N ratio was found in seaweed (55,643%) and fruit waste (27,857%). The conclusion is that agricultural waste, livestock waste, and fisheries waste after 1 month of fermentation contain adequate nutrients for optimizing critical land.

Polygalacturonase by Aspergillus Niger Using Seaweed Waste Under Submerged Fermentation: Production, Purification and Characterization

Crude oil, originating from fossilized organic materials, constitutes a crucial financial resource for all the countries with established deposits [1,2]. In general, oil reserves are allocated on the shelves of the ocean, on the land, as well as in the inland seas....

Pemberdayaan Kelompok Tani Rumput Laut dan Peternak Sapi di Kecamatan Suppa Kabupaten Pinrang

The purpose of this study was to train and guide people of Suppa village in Pinrang regency in cultivateEucheuma Cottonii seaweed, processing seaweed waste and making simple biogas. The problem was theparticipants were not understand the process of cultivating the seaweed, processing seaweed waste to become otherproducts, and processing cow manure to become biogas. Method used in this study was training by showingexamples of implementation and mentoring process. The result of this study showed that the farmers of EucheumaCottonii seaweed able to do seaweed cultivation, do marketing and business management properly, and thefisherwomen able to process seaweed waste into processed products in the form of seaweed jelly and cattle farmerscan utilize their cow manure into biogas.

The potential of seaweed waste (gracilaria sp. and eucheuma cottonii) as a medium density fiberboard (mdf)-based pot material for better water use efficiency in tomato plants

The demand for seaweed of the Gracilaria sp. and Eucheuma cottonii varieties is getting higher. The increasing seaweed culture can create a waste effect, as among other things, there are variations in quality that can cause rejection in the industry, as the harvest period is not universal, and neither is cleanliness in handling. One of the utilizations of seaweed waste that has a lignocellulose content is that it is one of the basic ingredients of Medium Density Fiberboard (MDF). Polybags as a growth medium can still cause the roots of the plants to grow in a circle of plastic. Polybag plastic is not easily degraded, so that there has been an increase in plastic waste dumping. The aim of this research is to determine the water use efficiency and the tomato plant growth rate using seaweed waste (Gracilaria sp. and Eucheuma cottonii) as an MDF pot material polybag substitute. This research used a completely randomized design with four treatments and five repetitions. The results of this research showed that the use of seaweed waste as a MDF-based pot material polybag substitute had a significant effect on the different water use efficiencies.

PENGARUH PENGGUNAAN PUPUK DARI LIMBAH RUMPUT LAUT TERHADAP PERTUMBUHAN TANAMAN BAYAM

This study aims to determine the effect of using seaweed waste fertilizer on the growth of spinach plants consisting of stem height, number of leaves, and leaf length. This study uses Completely Randomized Design (CRD) with media of seaweed waste concentration 25%, 30%, and 65%. Data were analyzed by variance (ANOVA) and continued with DMRT further testing. The results of this study indicate that the concentration of seaweed waste has a significant effect on changes in stem height, leaf number and leaf length which is the best treatment of soil concentration with seaweed waste is a concentration of 75-25% and shows 100% percentage of life.

Equilibrium study of binary mixture biosorption of Cr(III) and Zn(II) by dealginated seaweed waste: investigation of adsorption mechanisms using X-ray photoelectron spectroscopy analysis.

The alginate extraction residue (RES) from the Brazilian Sargassum filipendula was successfully employed as biosorbent in this binary equilibrium study, revealing a greater affinity and selectivity for Cr(III) than for Zn(II). Experimental results also revealed that the process is of endothermic nature and well adjusted by Langmuir-Freundlich binary model. The X-ray photoelectron spectroscopy (XPS) analysis revealed that coordination with hydroxyl groups of RES prevailed in Cr removal, followed by carboxyl-metal complexation. As far as Zn(II) is concerned, ion exchange with carboxylate groups of RES was the largest contributor. Nevertheless, scanning electron microscopy coupled with Fourier transform infrared spectroscopy indicated the participation of sulfate functions in a minor degree.