Heavy metals extraction from anaerobically digested sludge

2002 ◽  
Vol 46 (10) ◽  
pp. 1-8 ◽  
Author(s):  
M.M. Marchioretto ◽  
H. Bruning ◽  
N.T.P. Loan ◽  
W.H. Rulkens
Keyword(s):  
Heavy Metals ◽  
Municipal Wastewater ◽  
Extraction Efficiency ◽  
Extraction Process ◽  
Chemical Extraction ◽  
Second Phase ◽  
Specific Situation ◽  
Ph Values ◽  
Sequential Chemical Extraction ◽  
Removal Of Heavy Metals

This paper reports on the chemical extraction efficiency in the removal of heavy metals from sludge from an activated-sludge system, which receives as influent both industrial and municipal wastewater. Utilizing a series of chemical extractants in a sequential order comprised the first phase of the research, called sequential chemical extraction (SCE). The work started with the well-known Tessier method followed by Veeken and by Sims and Kline SCE schemes. Afterwards, modified versions of Tessier and Veeken schemes were applied. The second phase, named chemical extraction using pH progressive changes, concerns an alternative to the extraction process. Four acids were tested: nitric, hydrochloric, oxalic and citric and the pH values as well as the time were varied. Some conclusions reveal that although modifying Tessier and Veeken schemes provides more consistent results, SCE is still an imperfect method regarding specificity and selectivity. Besides, it is not advisable to apply one SCE scheme developed for one specific situation to another one, once the accurateness of the method depends on several factors such as sort of material and chemicals, contact time, temperature, etc. The extraction efficiency increases using nitric or hydrochloric acids at low pH values, promoting high extraction efficiency level.

Heavy metal removal from wastewater and leachate co-treatment sludge by sulfur oxidizing bacteria

2001 ◽  
Vol 44 (10) ◽  
pp. 53-58 ◽  
Author(s):  
L. C. Aralp ◽  
A. Erdincler ◽  
T. T. Onay
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Municipal Wastewater ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Heavy Metal Concentration ◽  
Organic Content ◽  
Removal Of Heavy Metals ◽  
Sulfur Oxidizing ◽  
Sulfur Oxidizing Bacteria

Heavy metal concentration in sludge is one of the major obstacles for the application of sludge on land. There are various methods for the removal of heavy metals in sludge. Using sulfur oxidizing bacteria for microbiological removal of heavy metals from sludges is an outstanding option because of high metal solubilization rates and the low cost. In this study, bioleaching by indigenous sulfur oxidizing bacteria was applied to sludges generated from the co-treatment of municipal wastewater and leachate for the removal of selected heavy metals. Sulfur oxidizing bacteria were acclimated to activated sludge. The effect of the high organic content of leachate on the bioleaching process was investigated in four sets of sludges having different concentrations of leachate. Sludges in Sets A, B, C and D were obtained from co-treatment of wastewater and 3%, 5%, 7% and 10% (v/v) leachate respectively. The highest Cr, Ni and Fe solubilization was obtained from Set A. Sulfur oxidizing bacteria were totally inhibited in Set D that received the highest volume of leachate.

Surface and Subsurface Decontamination Technology

2013 ◽  
Author(s):  
Matt Tuck ◽  
Beth Wray ◽  
Mark Musgrave
Keyword(s):  
Environmental Remediation ◽  
Extraction Process ◽  
Chemical Extraction ◽  
Specific Chemical ◽  
Substrate Complex ◽  
Inorganic Substances ◽  
Sequential Chemical Extraction ◽  
Contaminated Waste ◽  
Safety Considerations ◽  
Waste Destruction

A number of proven technologies applicable to the chemical and physical decontamination of radioactive and non-radioactive contaminants within the environmental remediation and radiological waste management sectors exist. Previous work generally acknowledges that these methods have limitations such as production of large volumes of waste, destruction of the substrate, complex safety considerations [1a] and application of special precautions to meet disposal acceptance criteria [2]. A method that removes a variety of contaminants from the surface and subsurface of porous materials, with minimal contaminated waste arisings, is highly desirable. TechXtract® is a patented, sequential chemical extraction process developed to remove radionuclides, PCBs, and other hazardous organic and inorganic substances from solid materials such as concrete, brick, steel, and exotic metals [3]. The technology uses multifarious task-specific chemical formulations and engineered applications to achieve surface penetration and removal of the contaminants from the atomic voids of metals and other substrates, or the capillaries and gel pores of concretes. TechXtract® is proven to remove a variety of contaminants from various substrates, allowing free release of the substrate as waste for disposal, or re-use, whilst producing minimal secondary waste. Data from testing of TechXtract’s capabilities and evidencing the technology’s efficacy during site based applied research and development is presented here.

scholarly journals Heavy metals Fractionation in Bagmati River Sediments, Nepal

2016 ◽  
Vol 9 (1) ◽  
pp. 119-128
Author(s):  
Sadhana Pradhanang Kayastha
Keyword(s):  
Heavy Metals ◽  
Total Concentration ◽  
River Sediments ◽  
Extraction Procedure ◽  
Absorption Spectrometry ◽  
Chemical Extraction ◽  
Geochemical Background ◽  
Sediment Samples ◽  
Sequential Chemical Extraction ◽  
Bagmati River

The aim of this work was speciation of heavy metals on the level of the geochemical background; in bottom sediments of the Bagmati River in Kathmandu valley. The distribution and accumulation of heavy metals in the sediments of the Bagmati River were investigated. Sediment samples from six locations were collected and characterized for metals content (cadmium, lead, copper and zinc). The determination of extractable heavy metals such as, Cd, Pb, Cu and Zn, in the sediment samples was carried out by atomic absorption spectrometry. The study has been conducted using five steps sequential extraction procedure described by tessier. Apart from total concentration, the distribution of the above metals into five fractions: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter, and residual, was studied by means of an analytical procedure involving sequential chemical extraction. The result obtained showed total metal concentration to be in the range of Cd 0.89-2.29 mg/kg; Pb 57.58-221mg/kg; Cu 52.2 -198.17 mg/kg and 78.23-362.90 mg/kg in all the areas studied. The fractionated toxic metals like Cd, and Pb were observed to be in the range of 15-36%, and 11- 29%, respectively, in mobile or bio-available fractions of sediments. This potentially mobile fraction could pose a serious threat, with respect to contamination of waterways and aquatic environment.Journal of Hydrology and Meteorology, Vol. 9(1) 2015, p.119-128

scholarly journals Assessment of heavy metal removal efficiencies by naturally fermented and a. niger fermented pineapple wastes from contaminated sewage sludge

2007 ◽  
pp. 429-438
Author(s):  
Dominica del Mundo Dacera ◽  
Sandhya Babel
Keyword(s):  
Citric Acid ◽  
Sewage Sludge ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Extraction Procedure ◽  
Extraction Process ◽  
Chemical Extraction ◽  
Sequential Chemical Extraction ◽  
Removal Efficiencies

Heavy metals in sewage sludge can pose a long term environmental risk due to their toxicity,non-biodegradability and consequent persistence, This study assessed the efficiencies ofvarious organic extractants such as naturally fermented and A�pergillus niger (A. niger)fermented raw liquid from pineapple wastes, in the chemical extraction process, to extract Cr,Cu, Pb, Ni and Zn, from anaerobically digested sewage sludge in Thailand. Pineapple wastesare a good source of sugar and protein and have been utilized experimentally in theproduction of citric acid by fennentation with the fungus A. niger. Comparison of theextraction efficiencies of these extractants with commercial citric acid was also investigated attwo hours leaching time and pH 3 and greater. Results of the study revealed that at pHapproaching 4, A. niger fermented liquid seemed to exhibit the best removal efficiency forpractically all metals studied, attaining as much as 72% removal for Zn, 70% for Ni, 50% forCr and 37% for Cu, although effectivity of removal seemed to be less apparent for Pb. Themost readily solubilized metal seemed to be Zn with the most removal of 92% attained bynaturally fermented raw liquid, The effectivity of removal by A. niger fem1ented liquid maybe due to the presence of citric acid and other carboxylic acids as confirmed by the HPLC andIR studies of the fem1ented liquid, Moreover, variation in metal removal efficiencies may beattributed to the fonns of metals in the sludge, as evidenced by chemical speciation studiesusing sequential chemical extraction procedure, with metals predominantly in theexchangeable and oxidizable phases showing ease of leachability,

scholarly journals Enhanced lipid extraction from microalgae in biodiesel production

2017 ◽  
Vol 71 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Myung-Gyun Kim ◽  
Hyun-Wook Hwang ◽  
Antony Nzioka ◽  
Young-Ju Kim
Keyword(s):  
Conversion Rate ◽  
Extraction Method ◽  
Extraction Efficiency ◽  
Fatty Acid Content ◽  
Lipid Extraction ◽  
Microwave Treatment ◽  
Extraction Process ◽  
Biodiesel Production ◽  
Chemical Extraction ◽  
Operation Control

In order to secure more effective lipid extraction method, this research investigated new lipid extraction method using laser with absorbent and sought its optimum operation control. In addition, this study compared lipid extraction efficiency and FAME conversion rate between laser extraction method at optimum condition and existing extraction method. Results from experiments for optimizing lipid extraction method using laser showed that the maximum extraction efficiency (81.8%) was attained when using laser with an output capacity of 75Wh/L. Extraction efficiency increased up to 90.8% when microwave treatment as pretreatment process was conducted. Addition of absorbents during lipid extraction process with laser showed higher extraction efficiency than laser and chemical method. It was also found that laser extraction method with absorbent had higher total fatty acid content (853.7 mg/g oil) in extracted lipid than chemical extraction method (825.4 mg/g oil). Furthermore, it had the highest FAME conversion rate (94.2%).

scholarly journals Impact of Mining Dump on the Accumulation and Mobility of Metals in the Bytomka River Sediments

2014 ◽  
Vol 40 (2) ◽  
pp. 3-19 ◽  
Author(s):  
Magdalena Jabłońska-Czapla ◽  
Sebastian Szopa ◽  
Czesława Rosik-Dulewska
Keyword(s):  
Heavy Metals ◽  
Ion Exchange ◽  
Bottom Sediments ◽  
River Sediments ◽  
Extraction Procedure ◽  
Residual Fraction ◽  
Chemical Extraction ◽  
Coal Waste ◽  
Waste Dump ◽  
Sequential Chemical Extraction

Abstract The research aim was to determine the long-term impact of the mine waste stored at the coal waste dump Hałda Ruda on the content of heavy metals in the bottom sediments of the Bytomka River. It is a watercourse flowing along this coal waste dump and has been under its influence for over fifty years. The research also attempted to determine the seasonality of changes (2 years) and mobility of selected elements. The article presents total contents of Cr, Mn, Ni, Cu, Zn, As, Cd and Pb in the bottom sediments collected from the Bytomka River. It also focuses on the distribution of these elements in particular geochemical fractions determined with the Tessier's sequential chemical extraction procedure. Total element contents were determined with an EDPXRF (Energy Dispersive X-ray Fluorescence) technique. The extractants of particular Tessier's fractions were determined quantitatively with an ICP-MS (Inductively Coupled Plasma Mass Spectrometry) spectrometer. The research results show that the stored waste significantly influences the contents of heavy metals in the Bytomka River bottom sediments. The lowest concentration of heavy metals was observed at the B1 spot (above the dump), while the highest one was measured at the B3 spot (below the dump). Sequential chemical extraction of the bottom sediments indicates that the Zn content in the ion-exchange and carbonate fractions diminished within a year. Nevertheless, Zn bound to Fe and Mn oxides acted in the opposite way. Mn, Zn and Pb are the most dangerous elements from the viewpoint of environmental hazards, as their total concentrations were high. Moreover, their high contents were observed in the most mobile (ion-exchange and carbonate) fractions. Extremely toxic Cd was bound to the oxide fraction to the largest extent. Cu was mainly bound to the organic fraction while environmentally hazardous Cr was bound to the residual fraction.

Technology Research for the Removal of Heavy Metals from Municipal Sludge

2013 ◽  
Vol 295-298 ◽  
pp. 1353-1358 ◽  
Author(s):  
He Ming Wang ◽  
Liang Shen ◽  
He Li Wang
Keyword(s):  
Heavy Metals ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Municipal Sewage ◽  
Chemical Extraction ◽  
Metals Removal ◽  
Removal Of Heavy Metals ◽  
Agricultural Use ◽  
Future Direction

Heavy metal pollution is one of the main obstacles of municipal sewage treatment plant sludge for agricultural use. This paper gives an overview of four kinds of commonly used techniques for heavy metals removal in sewage sludge: chemical extraction, bioleaching, electrokinetic technology and solidification - stabilization, also analyzed the future direction of development.

scholarly journals Simultaneous removal of heavy metals from drinking water by banana, orange and potato peel beads: a study of biosorption kinetics

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Risha Jasmine Nathan ◽  
Candace E. Martin ◽  
Dave Barr ◽  
Rhonda J. Rosengren
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Surface Heterogeneity ◽  
Simultaneous Removal ◽  
Potato Peel ◽  
Ph Values ◽  
Removal Of Heavy Metals ◽  
Initial Ph ◽  
Potato Peels ◽  
Experimental Values

AbstractBanana, orange and potato peels (BP, OP and PP, respectively) were immobilised to produce biosorbent beads that were employed for the biosorption of heavy metals from a cocktail solution containing As(V), Cd(II), Cr(VI), Cu(II), Hg(II) and Ni(II) ions. Drinking water conditions were maintained with neutral initial pH and low concentration of the ions. Batch experiments were performed for evaluating the effect of pH in the drinking water range (6.5–8.5). Results showed a significant increase in the biosorption capacity of the beads with respective to the uptake of As and Pb, whereas it decreased significantly for Cd, Cu, Hg and Ni ions at basic pH values. Approximate equilibrium biosorption of Cd, Cu, Hg and Ni was 89–92%, 79–87%, 84% and 71–80% by BP, OP and PP beads. The physisorption-based PFO model was the most suitable for the ions with biosorption capacities closer to the experimental values. BP and OP beads had better biosorption efficiencies relative to PP bead due to the higher surface heterogeneity observed by scanning electron microscopy coupled with energy-dispersive spectroscopy. An increase in the biosorbent concentration from one to ten BP beads significantly increased the biosorption percentage of the ions. The biosorption capacities of Cd, Hg and Ni uptake by one BP bead from a 1 mgL−1 cocktail solution were 3.4 ± 0.0, 5.3 ± 0.1 and 3.0 ± 0.0 mgg−1, respectively. Thus, BP beads were the most effective than for the simultaneous removal of heavy metals from drinking water.

scholarly journals Removal of Heavy Metals during Primary Treatment of Municipal Wastewater and Possibilities of Enhanced Removal: A Review

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1121
Author(s):  
Sylwan Ida ◽  
Thorin Eva
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Municipal Wastewater ◽  
Metal Removal ◽  
Metal Speciation ◽  
Heavy Metal Removal ◽  
Primary Treatment ◽  
Metal Concentrations ◽  
Heavy Metal Concentrations ◽  
Removal Of Heavy Metals

Resource reuse has become an important aspect of wastewater management. At present, use of sludge in agriculture is one of the major reuse routes. Conventional municipal wastewater treatment does not involve any designated process for removal of heavy metals, and these distribute mainly between effluent and sludge. Enhanced removal of heavy metals during primary treatment may decrease the heavy metal concentrations in both effluent and sludge from secondary treatment and promote long-term reuse of secondary sludge. This review considers heavy metal occurrence and removal during primary settling, together with possible treatment technologies for heavy metal removal in primary settlers and their theoretical performance. The variation in total heavy metal concentrations and dissolved fraction in raw municipal wastewater points to a need for site-specific assessments of appropriate technologies for improved heavy metal removal. Studies examining the heavy metal speciation beyond dissolved/particulate are few. Missing or disparate information on process parameters such as hydraulic retention time, pH and composition of return flows makes it hard to generalize the findings from studies concerning heavy metal removal in primary settlers. Coagulation/flocculation and use of low-cost sorbents were identified as the most promising methods for enhancing heavy metal removal during primary settling. Based on the available data on heavy metal speciation and removal during primary settling, sorption technologies may be most effective for enhancing the removal of Cu and Ni, while coagulation may be efficient for Cd, Cr, Cu, Pb, Zn and Hg removal (but not as efficient for Ni removal).

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