Pilot scale study on the ex situ electrokinetic removal of heavy metals from municipal wastewater sludges

2002 ◽  
Vol 36 (19) ◽  
pp. 4765-4774 ◽  
Author(s):  
Soon-Oh Kim ◽  
Seung-Hyeon Moon ◽  
Kyoung-Woong Kim ◽  
Seong-Taek Yun
Keyword(s):  
Heavy Metals ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Ex Situ ◽  
Removal Of Heavy Metals ◽  
Wastewater Sludges

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.

An“ex situ”microbial process for the removal of heavy metals from polluted soil: A case study of Ada rice field, Adani, Enugu State, Nigeria

2017 ◽  
Vol 21 (3-4) ◽  
pp. 128-137 ◽  
Author(s):  
Charles O. Nwuche ◽  
Oguejiofo T. Ujam ◽  
Janefrances N. Ihedioha ◽  
Charles C. Chime
Keyword(s):  
Heavy Metals ◽  
Rice Field ◽  
Polluted Soil ◽  
Ex Situ ◽  
Microbial Process ◽  
Removal Of Heavy Metals ◽  
Enugu State

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.

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).

scholarly journals Effects of Current, Electrodes Spacing and Operational Time on the Removal of Heavy Metals from Primary Treated Municipal Wastewater using Dielectrophoresis

2020 ◽  
Author(s):  
Abdulkarim Ibrahim Almukdad ◽  
Radwan Ahmad Firas Alfahel ◽  
Alaa AlHawari
Keyword(s):  
Heavy Metals ◽  
Municipal Wastewater ◽  
Aluminium Content ◽  
Applied Current ◽  
Ac Power ◽  
Removal Of Heavy Metals ◽  
Treated Municipal Wastewater ◽  
Alternative Current ◽  
Better Than ◽  
Operational Time

Electrocoagulation (EC) is an emerging technology that has been used to treat heavy metals from different kinds of wastewater. This paper discusses the effects of inducing Dielectrophoretic (DEP) force in EC system for the treatment of heavy metals from primary treated municipal wastewater. In order to achieve the optimum run of DEP, COMSOL software was used to identify the highest force that can be obtained by changing electrodes spacing and applied current. As per the results obtained from experiments and numerical methods, the optimum run was at operational time of 30 min, electrodes spacing of 0.5 cm and applied current of 600 mA (17.14 mA/cm2 current density). In both process aluminium electrodes were used and they were connected to alternative current (AC) power supply. The efficiency of AC-DEP was found to be better than AC-EC. The removal efficiencies of Fe and Mn using AC-DEP were 80.6% and 29.7% respectively, while AC-EC removed 78.23% of Fe and 28.8% of Mn. Moreover, the increase in the aluminium content using AC-DEP and AC-EC was 810.3% and 1330.8% respectively. Furthermore, the energy consumption of AC-DEP was 4.9 kWh/m3 while AC-EC consumed 5kWh/m3.

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