Sea Mud Research Articles

Dietary silicate minerals relieving cadmium or lead poisoning in juvenile sea cucumber, Apostichopusjaponicus

Industrial activities increase Apostichopus japonicus exposure to toxic heavy metals. This study evaluates the efficacy of three dietary silicate minerals (montmorillonite, zeolite, and kaolin) in relieving cadmium and lead toxicity in A. japonicus. Over four weeks, juvenile A. japonicus (7 − 9 g) were fed diets incorporating montmorillonite, zeolite, or kaolin, replacing sea mud at a 1:1 ratio. Experimental groups were: SM (control with sea mud), M (montmorillonite), Z (zeolite), and K (kaolin). Each group was exposed to cadmium (50 mg kg−1) or lead (100 mg kg−1) at the minimal toxic dose (MTD). Groups M and K demonstrated excellent growth performance, marked by improvements in weight gain rate (WGR), specific growth rate (SGR), feed conversion ratio (FCR), and survival rate (SR). Their coelomic fluid revealed higher enzymatic activities, such as acid phosphatase (ACP), alkaline phosphatase (AKP), catalase (CAT), and superoxide dismutase (SOD). Additionally, groups M and K showed a reduced accumulation of cadmium and lead in their tissues; group K notably excelled in mitigating intestinal tissue damage. In contrast, Group Z exhibited significantly poorer performance. In other aspects, the trends among the three experimental groups were generally similar: the activity of intestinal digestive enzymes declined, intestinal microbiota diversity decreased, and the stability of community composition increased. In summary, the supplementation of montmorillonite and kaolin effectively reduces cadmium and lead toxicity, diminishes oxidative damage, and promotes intestinal health in A. japonicus. These findings provide valuable insights for enhancing safety in A. japonicus aquaculture.

Anions exacerbate microbial corrosion of X80 pipeline steel induced by sulfate-reducing bacteria in the sea mud environment

Sulfate-reducing bacteria (SRB) present in sea mud pose a challenge to the safe operation of subsea pipelines. Chlorides and sulfates in sea mud promote the microbial corrosion of subsea pipelines by SRB. This study investigates the effects of sulfate and chloride on the microbial corrosion of X80 pipeline steel in the sea mud environment. The results indicate that sulfate serves as an electron acceptor, promoting the growth of SRB, while chloride regulates the osmotic pressure of SRB cells, affecting their bioactivity. SRB exhibit more aggressive corrosion behavior in sea mud with high concentrations of both chloride and sulfate.

Replacing sea mud with attachment of suspension cage can improve growth and gut health for sea cucumber Apostichopus japonicus

During the suspension cage culture procedure, a substantial quantity of attachments from the suspension cage will amass in the tidal flats, resulting in environmental pollution and resource wastage. The aim of the present study was to explore the feasibility of using attachments of suspension cage (ASC) as a raw feed material for sea cucumbers. Different ASC concentrations (0, 25, 50, 75, and 100%) were used in sea cucumber (Apostichopus japonicus) fed for 60 d. Replacing sea mud with 50% ASC significantly improved sea cucumber growth, reduced the feed coefficient, significantly increased the activity of intestinal digestive enzymes, improved the activities of acid phosphatase and alkaline phosphatase, improved the intestinal structure, and enriched intestinal microbiome diversity (P<0.05). Replacing sea mud with 75% and 100% ASC significantly improved sea cucumber total antioxidant capacity and total superoxide dismutase (P<0.05).Furthermore, expressions of c-myc gene, mapk-7 gene and fgfr-1 gene, which all three growth genes, significantly increased in the 50% ASC treatment compared to that in the control; whereas, that of gdf-8 gene, a negative growth regulator, was inhibited (P<0.05). Based on the quadratic regression analysis for the weight gain rate, the appropriate levels of ASC substitution were estimated as to be 44.28%. The results suggested the potential of ASC as a new raw feed material for sea cucumbers.

Numerical Investigation on Cathodic Protection of X80 Pipeline Steel in Marine Environment

Abstract Submarine pipelines are usually buried in sea mud, but part of the pipes will be exposed to seawater directly because of the change of seabed, the differences between sea mud and seawater result in different corrosion states. Generally, due to its large geometric size, complex medium, difficult to detect and other reasons, corrosion defects will cause greater harm to pipeline materials. A numerical analysis model of the outer surface corrosion of submarine pipelines was developed to simulate status of cathodic protection, furthermore, potential distribution and local density of current inside the defects was also analyzed and evaluated. The results indicates that: (1)The CP potential distributes more evenly in sea mud when the same sacrificial anode is used, and the cathodic protection current density needed to meet the anti-corrosion requirements is much larger in seawater than in sea mud.(2)Compared with sea mud, the polarization potential of the sacrificial anode in seawater is more negative, and the CP potential at the edge of anodes is the most positive in both sea mud and seawater. Furthermore, in seawater, the dissolution rate of sacrificial anodes closer to the seabed is lower, and anodes dissolve much faster at the inner surface, while it is just the opposite in sea mud.(3)Cathodic protection cannot ensure complete and effective protection at defect points. At defect bottom, the cathodic protection current is partially shielded, reducing the effectiveness of CP system on corrosion protection of pipelines. Moreover, the shielding effect of defect point on cathodic protection current has a great deal with the geometric shape of defect points, with decreasing width and increasing depth, the shielding phenomenon becomes more obvious.(4) Numerical simulation technique based on the finite element model provides a new method to solve this problem and plays a positive role in assessing anti-corrosion status and the service life of anodes.

Improving the Wettability and Fire Retardancy of Three-Phase Foam by Simulated Sea Mud

ABSTRACT As coal mining depths deepen and mining intensity increases, coal spontaneous combustion has become the leading cause of coal mining accidents. Sea mud is an environmentally friendly natural material rich in inorganic salts that inhibit coal oxidation. Based on sea mud, a new method of suppressing coal spontaneous combustion has been proposed by exploring the essential characteristics of sea mud three-phase foam with different concentrations. The results demonstrated that the contact angle of the three-phase foam solution with 20 wt% of sea mud decreased by 55.4° compared with that of pure water, the cross-point temperature of coal (245.85°C) increased by 16.15°C, and the peak temperature (490.57°C) increased by 16.47°C, which proved that its wettability and thermal stability were both enhanced. In conclusion, the three-phase foam with 20 wt% sea mud has been demonstrated to exhibit a superior ability to prevent the spontaneous combustion of coal.

Effects of dietary fermented attachments of suspension cage as a replacement for sea mud on growth and intestinal health of sea cucumber Apostichopus japonicus

In the suspension cage culture process, regular cleaning to remove epiphytic organisms from the cage is essential to prevent economic losses due to the sinking of the cage. However, after cleaning, many of attachments from the suspension cage accumulate in the tidal flats, causing environmental pollution and resource wastage. Moreover, because sea cucumbers (Apostichopus japonicus) are sedimentary food organisms, sea mud is typically added to their feed to varying degrees. However, long-term excavation of sea mud can destroy the marine environment. Therefore, developing an alternative new raw feed material to replace sea mud in sea cucumber feed is necessary to promote sustainable development of the A. japonicus aquaculture industry. The aim of this study was to explore the feasibility of using fermented attachments of suspension cage (FASC) as a raw feed material for A. japonicus. Different FASC concentrations (0, 25, 50, 75, and 100 %) were used in A. japonicus feed for 60 d. Replacing Sea mud with 100 % FASC significantly improved sea cucumber growth, reduced the feed coefficient, significantly increased the activity of intestinal digestive enzymes, improved intestinal structure, and enriched intestinal microbiome diversity. Furthermore, expressions of growth genes mapk-7 and fgfr-1 significantly increased in the 100 % FASC treatment compared with that in the control, and that of negative growth regulator gene gdf-8 was inhibited. The results suggested the potential of FASC as a new raw feed material for A. japonicus.

High-resolution organic and black carbon records in the South Yellow Sea over the last century

The mud depositional area ("mud area") of the South Yellow Sea serves as a prominent carbon sink within the Eastern Continental Shelf of China, offering crucial insights into human activities and climate fluctuations and its relationship with carbon cycle. This study investigates variations in total organic carbon (TOC) and black carbon (BC) concentrations in South Yellow Sea sediments. By combining 210Pb isotope analysis with grain-size profiling, the study distinguishes organic carbon origins, revealing the complex interplay between human activities and environmental shifts since the Industrial Revolution. The reasons for discrepancies between TOC and BC contents are analyzed, yielding the following results: (1) Sediment core QY-2 predominantly contains terrestrial-sourced organic carbon, primarily derived from the Yellow River and the Yangtze River. (2) Temporal fluctuations of BC in core QY-2 show distinct trends, periodic responses to human activities, particularly peaks in 1937 and 1945, linked to large-scale wars in China. (3) Relaxed carbon emission regulations in China, coupled with industrial growth spurred by the “reform and opening up” policy, led to a continuous rise in BC content from the mid-1960s to the 1980s, peaking in 1980. Subsequently, reduced BC values during the 1990s correlated with emission control policies and the shift from highly polluting domestic coal stoves to cleaner alternatives like liquefied petroleum gas or natural gas stoves. (4) BC content was influenced by the East Asian monsoon and Pacific Decadal Oscillation (PDO), with higher BC accumulation rates occurring in summer and depletion in winter. (5) Interestingly, changes in BC and TOC content exhibited a negative correlation. While grain size and material sources minimally influenced these discrepancies, the primary driver lay in the water's redox environment, impacting other TOC components and thereby causing variations in both TOC and BC content. This study of black carbon sources to sinks in the South Yellow Sea Mud Area holds significant implications for the broader Yellow Sea sedimentary system and provides support for understanding carbon cycle and marine environments.

Corrosion behavior of X60 pipeline steel in the presence of Sulfate Reducing Bacteria cultured in seawater and mud from the East China Sea

Sulfate-reducing Bacteria (SRB) corrosion is a serious threat to the safety of marine pipelines.To reveal the influence of the corrosion behavior of X60 pipeline steel in the presence of SRB cultured in seawater and mud from the East China Sea The corrosion behavior of X60 pipeline steel was studied with weight loss measurements, microstructure and membrane composition analysis, electrochemical measurements The corrosion rate in sterile seawater is 0.11 mm/y, whereas, in SRB-infested seawater, it increases by 245 % to 0.38 mm/y. In sterile sea mud, the corrosion rate is 0.15 mm/y, but in SRB-infested sea mud, it increases by 87 % to 0.28 mm/y. In the corrosive environment of seawater and mud in the East China Sea, SRB significantly accelerates the microbial corrosion of X60 pipeline steel. These findings provide theoretical guidance for further research on SRB corrosion mechanisms and corrosion control of marine pipelines.

Compound- and element-specific accumulation characteristics of persistent toxic substances and metals in sediments of the Yellow Sea

This study investigated the large-scale distributions of persistent toxic substances (PTSs) and heavy metals in sediments of the Yellow Sea, collected from six transects between latitudes 32 and 37 degrees north (n = 35). Elevated concentrations of polychlorinated biphenyls (PCBs) were detected near the mainland, with a predominance of low-chlorinated congeners (di to tetra, ∼60%), indicative of atmospheric deposition. Analysis of traditional and emerging polycyclic aromatic hydrocarbons (t-PAHs and e-PAHs) revealed notable enrichment in the Central Yellow Sea Mud Zone (CYSM), attributing fossil fuel combustion as the significant source. Styrene oligomers and alkylphenols exhibited notable accumulation near the Han River Estuary in South Korea and the Yangtze River Estuary in China, respectively. The accumulation of heavy metals was predominantly observed in the CYSM, with element-specific distribution patterns. Cluster analysis revealed distinct distribution patterns for PTSs and metals, highlighting their source-dependent and grain size-dependent behaviors. In addition, the distribution and accumulation of PTSs tended to depend on their partitioning coefficients, such as the octanol-air partition coefficient (log KOA) and octanol-water partition coefficient (log KOW). This study offers valuable insights into the sources, transport, and fate of hazardous substances in the Yellow Sea, emphasizing the necessity for targeted environmental management strategies.

Dual corrosion promotion of pipeline steel in sea mud induced by sulfate reducing bacteria: Bacteria concentration cell and electronic conduction of the biofilms covered sand grains

The microbiologically influenced corrosion (MIC) of X80 carbon steel in sea mud by sulfate reducing bacteria (SRB) was investigated and two unique MIC promotion mechanisms in sea mud were identified. For carbon steel at the seawater-mud interface, difference in the concentrations of sessile cells enhanced galvanic effect between the regions in seawater and sea mud, with the carbon steel in sea mud serving as the anode. SRB in sea mud established significant biofilms on sand grains, enabling the SRB attached on sand grains to participate in the biocatalytic cathodic process of MIC by the contact between sand grains and metal.

Corrosion Control and its Application in Marine Environment - A Review

It is natural to define marine corrosion in terms of the different zones in which the corrosion occurs such as atmosphere splash, tidal and sea mud etc. However, this study focused on issues affecting the marine structures, different types of corrosion and their impact on the marine steel structures as well as the machinery/equipment. Furthermore, several control measures of corrosion necessary to avert corrosion in marine environments were discussed. However, it was established that prolonged contact of marine structures with seawater would lead to corrosion as well as ruing the safety elements present. Thus, the study provides potential information to material scientists on the need for using structural steels of adequate mechanical properties.

Characteristic changes and environmental indicators of magnetic spherules in the South Yellow Sea mud area for about 7.5 ka

Magnetic spherules originate from anthropogenic and natural sources and can be differentiated based on morphology and composition. Using magnetic measurement, diameter measurement, scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) analysis of a 10 m sediment core in the mud area of the South Yellow Sea, we found that magnetic spherules occur at all observed depths of the core. The magnetic spherule concentrations vary from 10 spherules/0.5 g to 62 spherules/0.5 g. Here, concentrations generally less than 10 spherules/0.5 g are considered as the background value in the core. The peak value of magnetic spherules appeared at the 0.02, 0.3, 2 and 8 m, and their concentrations are 62, 52, 36, 48 spherules/0.5 g, respectively. According to the deposition age, concentration, diameter, morphology and chemical characteristics of the spherules, it is found that the spherules at 0.02 m are produced by industrial coal burning. A volcanic eruption event was the main responsible for the accumulation of spherules at 0.3 and 8 m, while the spherules located at 2 m are related to a wildfire event. Magnetic spherules are common in continental shelf regions and can well document the human activities and natural environment events.

The Screening and Identification of a Dextranase-Secreting Marine Actinmycete Saccharomonospora sp. K1 and Study of Its Enzymatic Characteristics.

In this study, an actinomycete was isolated from sea mud. The strain K1 was identified as Saccharomonospora sp. by 16S rDNA. The optimal enzyme production temperature, initial pH, time, and concentration of the inducer of this actinomycete strain K1 were 37 °C, pH 8.5, 72 h, and 2% dextran T20 of medium, respectively. Dextranase from strain K1 exhibited maximum activity at 8.5 pH and 50 °C. The molecular weight of the enzyme was <10 kDa. The metal ions Sr2+ and K+ enhanced its activity, whereas Fe3+ and Co2+ had an opposite effect. In addition, high-performance liquid chromatography showed that dextran was mainly hydrolyzed to isomaltoheptose and isomaltopentaose. Also, it could effectively remove biofilms of Streptococcus mutans. Furthermore, it could be used to prepare porous sweet potato starch. This is the first time a dextranase-producing actinomycete strain was screened from marine samples.

Uncovering the impact of sea mud-containing diet on fecal fragmentation and its potential environmental risks in recirculating aquaculture system of Apostichopus japonicus

A deep understanding of fecal characteristics and fragmentation mechanism is crucial for effectively removing the solid particles in recirculating aquaculture system (RAS) of Apostichopus japonicus, however, the underlying mechanism was still unclear. This study investigated the effects of diet with different sea mud addition on the fecal characteristics and microbiota. The experimental diet were the mixture of commercial feed and sea mud at the ratio of 1:1, 1:2, 1:3, 1:4 and 1:5, in which the added amount of sea mud was 50 %, 66.67 %, 75 %, 80 % and 83.33 %, respectively. The results showed that, at the end of aquaculture, Dx(50) in group 1:3 was the highest, while group 1:5 was the lowest. The fecal particle size distribution (PSD) appeared multi peak with the increase of sea mud addition. At the end of aquaculture, group 1:3 possessed the highest microbial diversity. BugBase phenotype prediction found that the microbial phenotypes in group 1:4 were mainly involved in functional expression, such as stress tolerance and potential pathogenicity. Significant correlation between environmental factors and fecal microbiota were found. Correlation analysis between fecal particle size and fecal microbiota showed that the abundance of pathogenic bacteria such as Vibrio, was higher on fecal particles with dispersed PSD. And NH4+-N removal rate decreased when Dx(10) decreased and Dx(90) increased. Thus, it was recommended that sea mud addition in diet should be <75 % in A. japonicus RAS.

Formulating Dead Sea Mud in Cosmetic Products, Its Effects on Skin, and the Underlying Biological Mechanism: A Review

Formulating Dead Sea Mud in Cosmetic Products, Its Effects on Skin, and the Underlying Biological Mechanism: A Review

Numerical Simulation of Crude Oil Leakage from Damaged Submarine-Buried Pipeline

Oil spill accidents in damaged submarine-buried pipelines cause tremendous economic losses and serious environmental pollution. The accurate prediction of oil spills from subsea pipelines is important for emergency response. In this study, the volume-of-fluid model, realizable k–ε turbulence model, and porous-medium model were employed to describe the process of an oil spill from a submarine pipeline to the sea surface. The effects of seawater density, seawater velocity, and pipeline buried depth on the transverse diffusion distance of crude oil and the time at which crude oil reaches the sea surface were obtained through numerical calculations. The calculation results show that, with a decrease in seawater density and an increase in seawater velocity and pipeline depth, the diffusion rate of crude oil decreases significantly, the maximum transverse diffusion distance increases and crude oil takes a long time to reach the sea surface. In particular, compared with a sea density of 1045 kg/m3, the transverse distance of a sea density of 1025 kg/m3 is increased by 0.091 m. When the seawater velocity is greater than 1.5 m/s, the diffusion of crude oil in seawater is significantly affected, the seawater velocity increases to 0.35 m/s, and the transverse diffusion distance of oil to the sea surface increases to 12.693 m. When the buried depth of the pipeline reaches 0.7 and 1.3 m compared to 0.1 m, the diffusion widths of crude oil in sea mud rise by 20% and 32.5%, respectively. The time required for crude oil to reach the sea surface and the transverse diffusion distance of crude oil migrating to the sea surface were analyzed using multiple regression, and the fitting formulas were obtained. The results provide theoretical support for accurately predicting the leakage range of submarine-buried pipelines and provide valuable guidance for submarine-buried pipeline leakage accident treatment schemes.

Removal of lead from aqueous solution using Dead Sea mud

This study aimed to investigate the performance of the (DSM) as an adsorbent for removing of lead from aqueous solution. Batch adsorption experiments were conducted using dried and burned (DSM) at different temperatures. The impact of the main parameters that affect the adsorption process; namely the pH, contact time, initial lead concentration, dose of (DSM), solution temperature and the burning temperature of the (DSM) were investigated.The result revealed that 100 % removal of lead ions was achieved at pH 7, room temperature, a dose of 2g of dried (DSM) with a mixing speed of 15 rpm, for 3 h contact time and initial concentration of lead in the solution of 100 mg/l. The adsorption capacity reached: 39.84 mg/g, 39.74 mg/g, 39.1 mg/g, 39.12 mg/g, and 34.45 mg/g for dry samples, and burned samples at 200, 500, 800, and 1000 °C respectively. Kinetic models showed that the pseudo-second-order kinetic model was better (R2 = 0.99) than the othere used models to describe the adsorption process.Regarding the isothermal models, it was found that the D-R is the best fit for lead adsorption, with (R2) of 0.90 indicating physicochemical adsorption mechanism. Thermodynamic studies found that at the adsorption process occurs spontaneously and is exothermic in nature with ΔHo value of −49.419 kJ mol− 1 and ΔSo = −13.558 kJ mol− 1 and ΔGo value at 25 °C = −45.31KJmol-1. It can be concluded that high removal efficiency of (Pb+2) can be achieved by using (DSM) as adsorbent which considered as a low cost, naturally existing material.

Natural and anthropogenic forcing on the fate of sedimentary organic matter in the South Yellow Sea during the Holocene

Long-term organic matter (OM) burial in the ocean is essential to the global carbon cycle. Mud deposits, such as South Yellow Sea mud deposit (SYSMD) located in the central South Yellow Sea (SYS), are ideal for the study of long-term OM burial. A sediment core YS-A from the SYSMD was analyzed for lignin phenols and bulk OM properties to reveal the driving forces of sedimentary OM (SOM) fate during the Holocene. SOM burial was found to be dominantly influenced by sea level rise and increased East Asian summer monsoon during 11.0–7.0 ka BP. During 7.0–1.0 ka BP, the fate of SOM was controlled by El Niño Southern Oscillation on the millennial time scale, and correlated with East Asian winter monsoon variability on the centennial time scale. Remarkably, anthropogenic perturbation has gradually overwhelmed long-term climate control on the fate of SOM since 1.0 ka BP, and this phenomenon became more evident after 0.4 ka BP.

Pengaruh Lumpur Laut Cair Serta Pemeberian Pupuk Kandang Sapi dalam Budi Daya Tanaman Cabai Rawit (Capsicum frutescens, L) Pada Lahan Gambut

This study to determine the effect of liquid sea mud and cow dung on the growth and yield of cayenne pepper plants on peat soils was carried out on the land of residents of Tnjung Rejo Paloh Panglima village, Percut Sei Tuan District, Deli Medium Regency, North Sumatra Province, from May to August 2023. The study was arranged in a Complete Randomized Design with two factors and each treatment combination was replicated three times. The first factor is the dose of liquid coastal sediment (0; 0.5; 1; 1.5 L/ plant), while the second factor is the dose of cow dung (0; 50; 100; 150 g/ plant). The results of the first experiment showed that there was no interaction between liquid sea mud and cow dung in affecting plant height, dry weight of plants, number of fruit plants, weight of chili plants and plant weight, While the application of cow dung significantly increases plant height, dry weight of plants and weight of fruit crops. Application of liquid sea mud plants 1 L and cow dung 100 g / plant can promote soybean growth and yield in peat soils. Keywords : Cayenne pepper, Sea mud, cow dung

Sedimentary evolution of the western North Yellow Sea mud patch: A Holocene perspective

The western North Yellow Sea mud patch has a unique location, abundant sediment supply and a complex sedimentary environment. Reconstructing its sedimentary evolution is crucial for a comprehensive understanding of source to sink process in the North Yellow Sea. Using core W03 collected from the mud patch, this study unravels its Holocene history through analysis of sedimentology, mineralogy and micropalaeontology. The results indicate that core W03 can be divided into three depositional units (DU). DU3 (538-461 cm) is composed of earthy yellow clayey silt and characterized by a hard layer. It was formed in the near-coast environment between 10.3 and 9.8 cal kyr BP, a hiatus period between Melt Water Pulse 1B and 1C events. DU2 (460-341 cm) was formed during the period of 9.8–6.5 cal kyr BP. As sea level rose, the westward retreat of the Yellow River mouth caused the transportation of Yellow River-derived sediment over longer distances, leading to an increase in flaky minerals. The rising sea level also induced a shift towards a reducing environment in the western North Yellow Sea. DU1 (340-0 cm) was formed after 6.5 cal kyr BP. During this period, the study area remained in a shelf shallow sea environment characterized by relatively strong chemical hydrolysis and reducing conditions. The intensification of the Yellow Sea Warm Current and an increase in Yellow River sediment transported to the sea led to an obvious increase in sedimentation rate after 2.3 cal kyr BP.