scholarly journals Heavy Metal Sorption by Sludge-Derived Biochar with Focus on Pb2+ Sorption Capacity at μg/L Concentrations

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1559
Author(s):  
Ida Sylwan ◽  
Hanna Runtti ◽  
Lena Johansson Westholm ◽  
Henrik Romar ◽  
Eva Thorin

Municipal wastewater management causes metal exposure to humans and the environment. Targeted metal removal is suggested to reduce metal loads during sludge reuse and release of effluent to receiving waters. Biochar is considered a low-cost sorbent with high sorption capacity for heavy metals. In this study, heavy metal sorption to sludge-derived biochar (SDBC) was investigated through batch experiments and modeling and compared to that of wood-derived biochar (WDBC) and activated carbon (AC). The aim was to investigate the sorption efficiency at metal concentrations comparable to those in municipal wastewater (<1 mg/L), for which experimental data are lacking and isotherm models have not been verified in previous works. Pb2+ removal of up to 83% was demonstrated at concentrations comparable to those in municipal wastewater, at pH 2. SDBC showed superior Pb2+ sorption capacity (maximum ~2 mg/g at pH 2) compared to WDBC and AC (<0 and (3.5 ± 0.4) × 10−3 mg/g, respectively); however, at the lowest concentration investigated (0.005 mg/L), SDBC released Pb2+. The potential risk of release of other heavy metals (i.e., Ni, Cd, Cu, and Zn) needs to be further examined. The sorption capacity of SDBC over a metal concentration span of 0.005–150 mg Pb2+/L could be predicted with the Redlich–Peterson model. It was shown that experimental data at concentrations comparable to those in municipal wastewater are necessary to accurately model and predict the sorption capacity of SDBC at these concentrations.

2001 ◽  
Vol 36 (4) ◽  
pp. 793-803 ◽  
Author(s):  
Tadeusz Skowroński ◽  
Jacek Pirszel ◽  
Barbara Pawlik Skowrońska

Abstract Metal sorption capacity of the granulated biosorbent derived from the waste biomass of Penicillium chrysogenum was examined. The potential metal sorption abilities of the biosorbent were estimated as the cation-exchange capacity, using a potentiometric titration. The total binding capacity, calculated for the pH range 3 to 8 was about 511 µeq/g dry weight. The granular biosorbent was capable of Cd, Zn, Cu and Pb binding. The kinetics of the heavy metal sorption were typical of the microbial dead biomass; metals were bound in the first few minutes. Sorption was a saturable process and the maximum sorption capacity, calculated from the Langmuir equation for the particular heavy metals was: 96 mg Pb; 21.5 mg Cd; 13 mg Zn and 11.7 mg Cu (per g dry weight). Optimum pH values for Cd, Zn and Cu sorption were about 7, while for Pb about 6. Heavy metal removal from different solutions was examined using the biosorption columns packed with P. chrysogenum, which efficiently removed Cd from 1 mM Cd solution, or Cd and Zn from the industrial wastewater. The studied biosorbent was capable of accumulating Cd and Zn even at the high Ca concentration.


2001 ◽  
Vol 44 (10) ◽  
pp. 53-58 ◽  
Author(s):  
L. C. Aralp ◽  
A. Erdincler ◽  
T. T. Onay

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.


2014 ◽  
Vol 25 (4) ◽  
pp. 51-54
Author(s):  
Anna Kwarciak-Kozłowska ◽  
Lucyna Sławik-Dembiczak ◽  
Bartłomiej Bańka

Abstract Phycoremediation is the use of algae for the removal or biotrans-formation of pollutants from wastewater. The study is a novel at-tempt to integrate nutrient (N and P) removal and some heavy met-als (iron, manganese and zinc) bioaccumulation from municipal wastewater using two microalgae species: Chlorella vulgaris and Scenedesmus armatus. The Chlorella vulgaris showed higher re-moval of total nitrogen (TN) both in influent and effluent waste water than Scenedesmus armatus. Nevertheless, more than 51% of total phosphorus (TP) in effluent and 36% in influent wastewaters were removed by Scenedesmus armatus. More efficient microalga in heavy metal removal in influent wastewater was Scenedesmus armatus. The results showed that Chlorella vulgaris was appropriate for TN removal and bioaccumulation of heavy metals from effluent wastewater. Nevertheless, Scenedesmus armatus was highly pref-erable for heavy metals removal from influent wastewater.


Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 111 ◽  
Author(s):  
Carolina Rodríguez ◽  
Eduardo Leiva

Due to the unique properties of carbon nanotubes (CNTs), they have attracted great research attention as an emergent technology in many applications including water and wastewater treatment. However, raw CNTs have few functional groups, which limits their use in heavy metal removal. Nevertheless, their removal properties can be improved by oxidation processes that modify its surface. In this study, we assessed the capacity of oxidized and double-oxidized multiwalled carbon nanotubes (MWCNTs) to remove heavy metals ions from acidic solutions. The MWCNTs were tested for copper (Cu), manganese (Mn), and zinc (Zn) removal, which showed an increment of 79%, 78%, and 48%, respectively, with double-oxidized MWCNTs compared to oxidized MWCNTs. Moreover, the increase in pH improved the sorption capacity for all the tested metals, which indicates that the sorption potential is strongly dependent on the pH. The kinetic adsorption process for three metals can be described well with a pseudo-second-order kinetic model. Additionally, in multimetallic waters, the sorption capacity decreases due to the competition between metals, and it was more evident in the removal of Zn, while Cu was less affected. Besides, XPS analysis showed an increase in oxygen-containing groups on the MWCNTs surface after oxidation. Finally, these analyses showed that the chemical interactions between heavy metals and oxygen-containing groups are the main removal mechanism. Overall, these results contribute to a better understanding of the potential use of CNTs for water treatment.


Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1121
Author(s):  
Sylwan Ida ◽  
Thorin Eva

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).


2012 ◽  
Vol 178-181 ◽  
pp. 507-511
Author(s):  
Zhi Min Zhang

The concentration of heavy metals in excess sludge from municipal wastewater treatment plants has restricted its convertion to soil fertilizer, so it is necessary to remove the heavy metals from sludge. In this article, the effects of heavy metal removal by some mineral acids such as HCl, H2SO4, H3PO4, HNO3 were analysed, when treating excess sludge from a second sediment tank in municipal wastewater treatment plants. To improve the treatment, a combination of H2O2 and acid was also investigated. Consequently, the difference of heavy metal removal among those acids was showed. Its removal of Hg by HNO3 was better than by other acids. Lower pH enhanced the dissolving of heavy metal, yet the removal of Cr was insensitive to the pH. Aided by H2O2, the removal by the acid was enhanced. The suitable dosage of H2O2 was specially related to the solid content of sludge, pH and the acid kind.


2016 ◽  
Vol 103 (1) ◽  
pp. 35-44
Author(s):  
Algirdas Motuzas ◽  
Rimantas Vaisvalavičius ◽  
Nomeda Sabienė

Author(s):  
C. Kowsura ◽  
◽  
B. Pangkumhang ◽  
P. Jutaporn ◽  
V. Tanboonchuy

2020 ◽  
Author(s):  
Yıldırım İsmail Tosun

There is a great concern about surface water pollution with high level mercury, lead (Pb) over 10 mg/l, 30 mg/l to the fishing lakes and streams in Şırnak Province even contaminating fresh water fishing and poisonening of human by merury and lead in thr region. The chromium over 50 mg/l from industrial seepages was disposed to lakes and streams in our country. There is a great green concern prompting land in order to control acidic mine waters so that the research study controlled and avoided hazardous metal limits of residual stream contaminants of heavy metals by sorption local clay and zeolite compost. The contamination rate changes to those based on seepage concentrations and wetness. The stream amendments, such as shale char carbonized from Şırnak asphaltite containing 52–60% shale activated by acid washing under microwave radiation as geo material composted for waste water treatment should control contaminated effluents concentration. The field studies to evaluate the stability of heavy metal concentrations and salts were scarce. The initial objective of this study was to determine the effects of seepage flow to surface and groundwater from the industrial discharge. In this study, important investigations have been made on composite granules production with Şırnak shale char and zeolite feed in order to activated in microwave oven 2 M HCl dissolution. The compost sorbent for high level heavy metal sorption in laboratory water packed bed column adsorption compost system. However, the results of filled packed bed zeolite yield high metal transfer to compost. Due to the complex chemistry of shale pores, and high porosity, heat conduction improved in the microwave sorption depended on granule size decreased. The other heavy metal sorption distribution was changed in the activation dependent on the microwave heating power.


2020 ◽  
Author(s):  
Amy Lam ◽  
◽  
Todd Longbottom ◽  
Nelli K. Bodiford ◽  
Omar R. Harvey

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