Sea Nodule Research Articles

By using low-cost Adsorbents process elimination of heavy metals from wastewater

The beginning of industrialization human being has observed a variety of environmental concerns on the earth. The industrialization has not simply carried growth and affluence but finally troubled the environment. One of the crashes is noticeable, in form of water pollution. Now the present study of heavy metal pollution of water body has been talk over. Effluents from an unlimited amount of industries viz., textile, tannery, dyes, pigment, paint, wood processing, electroplating, leather, petroleum refining etc., have a key amount of heavy metal in their wastewater. The conventional technique of treatment heavy metal contamination contains chemical precipitation, membrane separation, chemical oxidation, ion exchange, electro dialysis, reverse osmosis, etc. These procedures are costly, energy intensive and often linked with creation of toxic by-product. Hence, the adsorption has been experimental as a cost-efficient method for treatment of heavy metals removal from wastewater. In the existing study numerous inexpensive adsorbent has been an analysis as a reduction of heavy metal effluence from wastewater. These adsorbent include resources of natural origin similar to zeolites, peat moss, peat moss, chitin, clay are find to be a real agent for elimination of lethal heavy metal like Cu, Ni, Hg, Zn, Cr , Pb, Cd, etc. Distinctly from these, a range of farming wastes like waste tea, rice husk, black gram neem bark, walnut shell, etc. Also known to be an influential adsorbent for the eliminating heavy metal from wastewater. at the side of that inexpensive or low-cost manufacturing byproduct like lignin, fly ash, iron (III) red mud, hydroxide and coffee husks, tea factory waste, Areca waste, sugar beet battery industry waste, pulp, waste slurry, blast furnace sludge, grape stalk wastes, sea nodule residues have been found for their methodological option for removal toxic metal from waste water.

Heavy Metal Removal from Wastewater Using Low Cost Adsorbents

With the onset of industrialization mankind has witnessed various environmental issues in the society. This industrialization has not only brought development and prosperity but eventually disturbed the ecosystem. One of the impacts is visible, in form of water pollution. In the present study heavy metal contamination of water bodies has been discussed. Effluents from large number of industries viz., electroplating, leather, tannery, textile, pigment & dyes, paint, wood processing, petroleum refining, photographic film production etc., contains significant amount of heavy metals in their wastewater. The conventional methods of treatment of heavy metal contamination includes chemical precipitation, chemical oxidation, ion exchange, membrane separation, reverse osmosis, electro dialysis etc. These methods are costly, energy intensive and often associated with generation of toxic byproducts. Thus, the adsorption has been investigated as a cost effective method of removal of heavy metals from wastewater. In the present study various low cost adsorbent has been reviewed as an abatement of heavy metal pollution from wastewater. These adsorbent includes materials of natural origin like zeolites, clay, peat moss and chitin are found to be an effective agent for removal of toxic heavy metals like Pb, Cd, Zn, Cu, Ni, Hg, Cr etc. Apart from these various agricultural wastes like rice husk, neem bark, black gram, waste tea; Turkish coffee, walnut shell etc. were also established as a potent adsorbent for heavy metal removal. Beside that low cost industrial by products like fly ash, blast furnace sludge, waste slurry, lignin, iron (III) hydroxide and red mud, coffee husks, Areca waste, tea factory waste, sugar beet pulp, battery industry waste, sea nodule residue and grape stalk wastes have been explored for their technical feasibility to remove toxic heavy metals from contaminated water.

Efficient removal of aqueous lead by leached sea nodules residue

The sea nodule leaching residue/wastes (generated after recovery of copper, nickel, and cobalt) are hazardous to the environment due to fine nature and heavy metal contents. Here, we demonstrate highly efficient adsorptive remediation of aqueous lead using the residue generated in reduction roast–ammonia leaching of sea nodules. Characterization of leached sea nodule residue (SNR) revealed fine granulometry (d50 = 11.4 μm) and high surface area of 66.7 m2 g−1. Batch adsorption experiments are performed varying temperature, pH of solution, contact time, initial lead concentration, adsorbent dose, etc. to determine lead removal capacity of SNR. Excellent adsorption capacity of lead onto SNR to the tune of 2,500 mg g−1 is achieved, which is quite high in comparison with other adsorbents. Kinetics and thermodynamic aspects of adsorption are studied. The pseudo-second-order model is found applicable to the lead removal kinetics. SEM and XRD investigations showed lead adsorbed on the surface of SNR in the form of hexagonal crystalline hydrocerussite.

Biochemical Alteration in the Labeo rohita Tissues Following Exposure to the Effluent Generated during Extraction of Metals from Polymetallic Sea Nodules

Effect of the effluent generated during extraction of precious metals from polymetallic sea nodules have been illustrated by analyzing the biochemical alterations in freshwater fish Labeo rohita. Increase or decrease in the different biomolecules in various tissues (skin, muscles, gills, liver, kidney, and brain) observed was discussed in the light of stress caused by exposures of this effluent. Decrease in concentration of glycogen, total lipids, cholesterol, and total protein in most of the tissues indicate their role in providing the continuous energy requirement under toxic stress in the exposed fish. Reduced DNA and RNA concentration in exposed fish showed effluent toxic effect on DNA synthesis and transcriptional level. With the prolongation of exposure, reduction in activities of aspartate amino transferase, alanine amino transferase, and alkaline phosphatase were observed in all the exposed tissues indicating their cellular degeneration. In conclusion, the sea nodule effluent was found to be very toxic and have negative health impact on the fish.

Metal bioaccumulation in fish Labeo rohita exposed to effluent generated during metals extraction from polymetallic sea nodules

The aim of this study was to investigate the potential impact of effluent released during metals extraction from polymetallic sea nodules at the Pilot Plant at National Metallurgical Laboratory, India, by analysing different metal (Mn, Cu, Zn, Fe, Pb and Cr) concentrations in six tissues (skin, muscles, gills, liver, kidney and brain) of the fish Labeo rohita. Of the six analysed tissues of sea-nodule-effluent-exposed fish, liver accumulated highest concentration of most of the metals (2.91–287.36 mg kg−1) while muscles (2.1–81.14 mg kg−1) lowest. While the concentration of Fe was maximum (60.41–218.7 mg kg−1) in all the tissue systems (except muscles and liver), Pb was minimum (0.8–2.91 mg kg−1). Accumulation of most of the metals in all the tissues was above the safe limits as recommended by Food and Agricultural Organisation that indicate metal’s potential hazardous impact on the fish. High bioaccumulation factors for these metals in the different tissues revealed that metals were extensively bio accumulated and bio concentrated. The time-dependent variation in metal pollution index illustrated increase in gross metal load (p < 0.05) in different tissue components with increase in exposure period. In conclusion, the sea nodule effluent was found to cause adverse health impact on the fish which in turn might also affect the human health when consumed.

Extraction of rare earth metals from deep sea nodule using H2SO4 solution

Leaching of rare earth (RE) metals from the Pacific Ocean sea nodule was carried out in H2SO4 medium. Preliminary study was performed to ascertain the existence of rare earth elements in the sea nodule crust. Concentration of H2SO4 and temperature were found as the key factors which enhance the dissolution rate of rare earth metals. The maximum average RE leaching efficiency of 83.03% was obtained using 3M H2SO4. At the above condition, leaching of most of the RE was ≥90% and the remaining metals were; Ce 44.6%, La 55.3%, Nd 84.7%, Eu 85.8%, Pr 76.4% and Th 78.8%, in which the co-extraction of other base metals like Fe, Co, Ni, Cu was high. Dilute acid i.e. 0.2M of H2SO4 and temp. 45°C was found to be best for optimum extraction (57.6%) of total rare earth, where the co-extractions of other base metals (Cu, Co, Ni, Mn and Fe) are very less.

Studies on Removal of Low Content Copper from the Sea Nodule Aqueous Solution using the Cationic Resin TP 207

Selective removal of copper remaining in the raffinate, obtained after solvent extraction of copper with LIX 84-I from the sea nodule leach solution, containing 0.512 g/L Cu(II), 0.212 g/L Fe(III), 15.16 g/L Ni(II), and 2.012 g/L Co(II), was carried out with TP 207, in the batch and column adsorption system. The operational factors affecting the copper adsorption such as initial copper ion concentration (0.05–1.0 g/L), pH (1–4), resin dosage (5–100 g/L), and temperature (293–338 K) were investigated. Adsorption of copper was found to be maximum at an equilibrium pH of 1.97 without any adsorption of other metal ions in the solution and was strongly affected by the resin dosage. Adsorption equilibrium data was well fitted with the Langmuir isotherm, and the monolayer adsorption capacity of copper ion was determined as 68.7 mg g−1, at 298 K. The positive values of ΔHo (11.5, 10.4, and 10.1 kJ mol−1) determined at corresponding initial copper concentrations: 0.1, 0.3, and 0.5 g/L, respectively, in the solution, indicated that the adsorption was endothermic in nature. Kinetic studies confirmed that the adsorption of copper followed pseudo second order reaction with intra particle diffusion.

Oxidative decolorization of methylene blue by leached sea-nodule residues generated by the reduction-roasting ammoniacal leaching process

The leached residue, generated after selective extraction of Cu, Ni and Co by reductive-roasting ammoniacal leaching of sea nodules, was characterized by various physicochemical methods. The finely divided residue, containing mainly manganese carbonate/silicates and manganese(III,IV) (hydr)oxides along with iron oxides, showed a lower surface area (66.3 m2 g−1) than that of the parent sea nodule (130 m2 g−1). The catalytic efficiency of water-washed sea nodule residue (WSNR) was evaluated taking oxidative decolorization of methylene blue (MB) as the test reaction. The extent of decolorization was decreased with increase in pH but increased in the presence of H2O2 or NaCl. Decolorization of MB occurred in two consecutive steps; the rate constant of the first step was ∼ 10 times higher than that of the second step. The formation of a surface precursor complex between WSNR and MB at a rate-limiting step, followed by electron transfer from MB to the active metal centre of WSNR and release of product(s), was proposed as the decolorization process.

Recovery of molybdenum from the sea nodule leach liquor by solvent extraction using Alamine 304-I

Separation and recovery of molybdenum was investigated from the sea nodule leach liquor containing 0.505 kg/m 3 Mo(VI), 0.212 kg/m 3 Fe(III),12.08 kg/m 3 Cu(II), 2.012 kg/m 3 Co(II) and 15.16 kg/m 3 Ni(II). The recovery process was carried out in two key steps: (i) Solvent extraction of Mo(VI) from the leach liquor using Alamine 304-1 dissolved in kerosene and (ii) Preparation of MoO 3 from stripped solution by crystallization followed by thermal decomposition of ammonium polymolybdate crystals. In the solvent extraction study, the effects of several operational factors like contact time, pH, extractant concentration and different stripping reagents were examined to establish suitable conditions for effective extraction and stripping of molybdenum. The number of stages required for extraction and stripping were determined from a McCabe Thiele diagram and confirmed by a counter current simulation study. Enrichment of approximately 6.05 kg/m 3 Mo(VI) into the loaded organic phase was achieved with 10% (v/v) Alamine 304-1, at equilibrium pH 1.62, and A:O = 12:1. The McCabe Thiele diagrams at A:O = 1:16 with 5 M NH 4OH + 2.5 M (NH 4) 2CO 3 showed two theoretical stages needed for quantitative stripping of molybdenum. Ammonium polymolybdate was crystallized from the stripped solution (96.79 kg/m 3 Mo) and molybdenum trioxide was obtained by thermal decomposition at 400 °C with purity of 99.9%.

Adsorptive Removal of Phosphate Ions Using Leached Sea Nodule Residue Generated by the Reduction–Roasting Ammoniacal Leaching Process

The present study was an attempt to find an alternative use for the leached residue generated after the selective extraction of Cu(II), Ni(II) and Co(II) ions during the reduction-roasting ammoniacal leaching of Indian Ocean sea nodules, so that the latter may be used as an adsorbent for the removal of phosphate ions from aqueous media. Physicochemical characterization revealed that the leached residue was a complex mixture of oxides of mainly manganese and iron along with MnCO3. Adsorption studies of the water-washed leached residue (WSNR), varying the pH, phosphate ion concentration, WSNR dosage, heat treatment and the presence of interfering anions in solution, indicated that phosphate (P) ion uptake increased with increasing heat-treatment temperature and pH, to attain a maximum value at 400 °C and a pH value of ca. 5.0, but thereafter decreased on increasing the heat-treatment temperature and pH further. The adsorption data were best fitted by the Freundlich isotherm model. Desorption studies showed ...

Removal of Pb(II) from industrial wastewater by using various natural materials – a review

Lead’s history in science, medicine and technology has been overshadowed by its notoriety as a poison in homicides. Lead is viewed as being synonymous with toxicity. Dangerous lead concentration in natural, as well as industrial wastewater, is now a worldwide problem and often referred to as a 20th–21st century calamity. Existing overviews of lead removal include technologies that have traditionally been used (oxidation, precipitation/coagulation/membrane separation) with far less attention paid to adsorption. No previous review is available where readers can get an overview of the sorption capacities of both available and developed sorbents used for lead remediation. Most of the valuable available literature on lead remediation by adsorption has been incorporated. Lead sorption by commercially available carbons and other low-cost adsorbents developed from various natural materials are surveyed and critically reviewed and their sorption effi ciency compared. Some commercially available adsorbents are also surveyed. An extensive table summarizes the maximum percentage of Pb(II) uptake, optimum pH, isothermal model fi t and thermodynamic parameters of various adsorbents. Some low cost adsorbents prepared from various natural materials are superior including bagasse fl y ash, bone powder, sea nodule, olive cake, polymerized banana stem, tea waste, carbons developed from agricultural waste (coconut shell carbon and palm shell carbon), biosorbents (modifi ed lignin and microspore), phosphogypsum and some commercial adsorbents, which included activated carbon, carbon aerogel tested for lead removal come out to be superior.

Studies on the Extraction of Manganese from Sea Nodule Residue as Ferrosilicomanganese

Most of the extraction processes developed for the polymetallic sea nodules concentrated mainly on the recovery of strategically important metals viz. Cu, Ni and Co. The residue generated in such processes is quite high enough to upset the environmental balance for industrial scale operation. The economics of the process too cannot be favourable if manganese in the residue is not recovered. In this study an attempt has been made to utilize this residue, containing appreciable amount of manganese (about 20%) for producing ferrosilicomanganese, an important ferroalloy primarily used for deoxidation in the steel industry, through smelting process. In order to have an alloy of standard grade, the residue is enriched in its manganese content, by blending it with ferromanganese slag. Bench scale studies indicate that it is possible to produce ferrosilicomanganese, of the grade required by the steel industry, by reduction smelting of the sea nodule residue with ferromanganese slag. Metal recovery, however, was less because of metal entrapment.

A study on arsenic adsorption on polymetallic sea nodule in aqueous medium

A detailed study on As(III) and As(V) adsorption on polymetallic sea nodule in aqueous medium has been reported. Elemental composition of sea nodule comprises primarily, iron, manganese and silicon with trace quantities of aluminium, copper, cobalt and nickel. As(V) adsorption on sea nodule is dependent on pH while As(III) is insensitive to it. Adsorption data broadly follow Langmuir isotherm. Kinetic data follow a pseudo-second-order model for both As(III) and As(V). Arsenic loading on sea nodule is dependent on initial arsenic concentration. Optimum As(III) loading is 0.74 mg/g at 0.34 mg/L and for As(V) it is 0.74 mg/g at 0.78 mg/L. As(III) adsorption is broadly independent of ionic environment. Except for PO 4 3−, As(III) adsorption is not influenced by anions but cations influence it significantly. As(V) adsorption, on the other hand, is influenced by anions and not by cations. Experimental evidence indicates an inner sphere complex for As(III) and partial inner and partial outer sphere complex for As(V). Both As(III) and As(V) adsorptions are marked with very little desorption in the pH range of 2–10. Sea nodule can speciate As(III) and As(V) in groundwater at or above pH 6. Sea nodule was successfully tested as an adsorbent for the removal of arsenic from six contaminated groundwater samples of West Bengal, India, containing arsenic in the range 0.04–0.18 mg/L.

Systematic studies on adsorption of lead on sea nodule residues

Lead adsorption from aqueous solutions was studied with the aim of detoxifying industrial effluents before their safe disposal onto land or into river waters. Sea nodule residue (SNR), a waste material containing oxides and oxyhydroxides of manganese, iron, silicon, etc., was used as an effective adsorbent for lead in this study. The effect of various parameters such as contact time, initial lead concentration, pulp density, particle size of the adsorbent, pH, and temperature was studied to optimize the conditions for maximum adsorption. Adsorption followed first-order kinetics and 99% of lead adsorption was achieved at a solid:liquid ratio of 1:330, in the pH range 5.5–6.0 at a particle size of − 150 μm in 8 h for solution containing 200 ppm lead. The adsorption capacity was found to be 99.0 mg of lead per gram of SNR and the adsorption isotherms followed the Langmuir and Freundlich adsorption models. The mechanism of adsorption of lead onto the sea nodule residue was also investigated. It was possible to reduce the lead level from 25–200 ppm to acceptable levels (0.1 ppm) by adsorption over this solid waste.

A comparative adsorption study of copper on various industrial solid wastes

AbstractThe adsorption behavior of Cu on three solid waste materials—sea nodule residue (SNR), fly ash (FA), and red mud (RM)—was investigated. The effects of various parameters, such as pH of the feed solution, contact time, temperature, adsorbate and adsorbent concentration, and particle size of the adsorbent, were studied for optimization of the process parameters. Adsorption of copper increased with increasing time, temperature, pH, and adsorbate concentration, and decreased with increasing initial copper concentration. The equilibrium data fit well with the Langmuir and Freundlich isotherms in the case of SNR, but not on RM and FA, because there was no appreciable effect of temperature on the metal removal on these two adsorbents. The adsorption of copper on SNR followed first‐order kinetics involving the surface complex formation mechanism on the charged surface. Under the optimized conditions the adsorption capacity for copper was found to be 19.65 mg/g of SNR, 1.98 mg/g of FA, and 2.28 mg/g of RM. Thus the adsorption capacity of SNR was found to be more than that of activated carbon, thus making it suitable for the treatment of industrial effluents to reduce the level of copper within the permissible limits for its land disposal (3 mg/L) according to ISI guidelines. © 2004 American Institute of Chemical Engineers AIChE J 50: 2430–2438, 2004

Removal of zinc from aqueous solutions using sea nodule residue

Sea nodule residue (SNR), a solid waste generated during the processing of polymetallic sea nodules for copper, nickel, and cobalt recovery, has been demonstrated to be an effective adsorbent for removing an inorganic pollutant such as zinc from wastewaters/industrial effluents by adsorption. The technology offers the potential for inexpensive recovery and reuse of a material normally discarded as a solid waste. Metal removal by this adsorbent was compared favorably with those achieved by commercial adsorbents. The adsorption experiments were performed, while varying adsorbent particle size (152–53 μm), adsorbent concentration (0.2–3% (w/v)), initial zinc concentration (75–500 mg l −1), shaking time (0.08–24 h), pH (1–6), and temperature (303–333 K). About 2.0 g of SNR was found to be sufficient to remove 99.8% of 200 mg l −1 zinc from 100 ml aqueous solution in 4 h, and the optimum pH value for maximum adsorption was found to be 5.5. The kinetic curves show very clearly the selectivity of SNR for zinc. The uptake obeys both the Freundlich and the Langmuir isotherms. The applicability of Lagergren kinetic model has also been investigated. Thermodynamic parameters were calculated to understand the nature of adsorption.

Removal of lead from contaminated water bodies using sea nodule as an adsorbent

Adsorption of water soluble lead on polymetallic sea nodule has been studied in detail. Complete decontamination of lead is possible by appropriate sea nodule dosing. Adsorption is also dependent on pH and best adsorption is achieved at pH 6. Beyond pH 6, the desorption of lead from sea nodule surface is practically zero. Residual metal concentrations in the filtrate after adsorption is negligible. Both Freundlich and Langmuir isotherms may reasonably explain adsorption of lead on sea nodule. Chemically bound moisture plays a very crucial role in lead adsorption. Lead adsorptive capability of sea nodule is practically destroyed when calcined at a temperature of 900°C. Lead loading capacity of sea nodule has been estimated at 440 mg of lead per gram of sea nodule. The performance of sea nodule as a lead adsorbent has been successfully tested over six simulated lead contaminated water systems. Lead loading capacity of sea nodule compares favorably with other adsorbents like activated carbon, ion exchange resin, anionic clay, granulated blast furnace slag and natural and treated zeolites.

Computational elimination of interelemental interference in the analysis of copper, cobalt and nickel in polymetallic sea bed nodules by flame atomic absorption spectrometry

A method has been described for the estimation of Cu, Co and Ni in polymetallic sea bed nodule samples by flame atomic absorption spectrometry using single component calibration standards. Interelemental interference plays a crucial role in the estimation of Cu, Co and Ni by flame AAS. Calibration by multicomponent matrix matching standards often fails because of wide variations in the compositions of actual samples. Cu, Co and Ni values are depressed in the presence of appreciable amounts of Fe and Mn present in the sea nodule matrix. Observed interferences have been eliminated computationally using a two parameter theoretical model. The method has been successfully applied for the estimation of Cu, Co and Ni in real life sea nodule samples by flame AAS using single component calibration standards.