scholarly journals PAMPS-graft-Ni3Si2O5(OH)4 multiwalled nanotubes as a novel nano-sorbent for the effective removal of Pb(ii) ions

RSC Advances ◽  
2020 ◽  
Vol 10 (13) ◽  
pp. 7619-7627 ◽  
Author(s):  
Chunmei Xiao ◽  
Jianming Lin
Keyword(s):  
Multiwalled Nanotubes ◽  
Effective Removal

PAMPS-g-Ni3Si2O5(OH)4 NTs for the effective removal of Pb(ii).

Clay liner materials for land disposal of hazardous non-metal wastes

1996 ◽  
Vol 33 (8) ◽  
pp. 71-77
Author(s):  
I. M.-C. Lo ◽  
H. M. Liljestrand ◽  
J. Khim ◽  
Y. Shimizu
Keyword(s):  
Sorption Capacity ◽  
Organic Anion ◽  
Surface Exchange ◽  
Clay Liner ◽  
Effective Removal ◽  
Exchange Constants ◽  
Anionic Species ◽  
Surface Ligand ◽  
Land Disposal

Simple land disposal systems for hazardous and mixed wastes contain heavy metal cationic species through precipitation and ion exchange mechanisms but typically fail by releasing soluble organic and inorganic anionic species. To enhance the removal of anions from leachate, clays are modified with coatings of iron or aluminium cations to bridge between the anionic surface and the anionic pollutants. A competitive surface ligand exchange model indicates that surface coatings of 10 meq cation/gm montmorillonite under typical leachate conditions increase the inorganic anion sorption capacity by at least a factor of 6 and increase the intrinsic surface exchange constants by more than a factor of 100. Similarly, metal hydroxide coatings on montmorillonite increase the organic anion sorption capacity by a factor of 9 and increase the intrinsic surface exchange constants by a factor of 20. For historical concentrations of non-metal anions in US hazardous and mixed waste leachate, sorption onto natural clay liner materials is dominated by arsenate sorption. With cation coatings, anion exchange provides an effective removal for arsenate, selenate, phenols, cresols, and phthalates. Engineering applications are presented for the use of modified clays as in situ barriers to leachate transport of anionic pollutants as well as for above ground treatment of recovered leachate.

scholarly journals Applications of Biocatalysts for Sustainable Oxidation of Phenolic Pollutants: A Review

2021 ◽  
Vol 13 (15) ◽  
pp. 8620
Author(s):  
Sanaz Salehi ◽  
Kourosh Abdollahi ◽  
Reza Panahi ◽  
Nejat Rahmanian ◽  
Mozaffar Shakeri ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Operating Conditions ◽  
Phenolic Pollutants ◽  
Petroleum Refinery Wastewater ◽  
Start Up ◽  
Low Concentrations ◽  
Effective Removal ◽  
Wide Range ◽  
Loading Effects ◽  
Spent Caustic

Phenol and its derivatives are hazardous, teratogenic and mutagenic, and have gained significant attention in recent years due to their high toxicity even at low concentrations. Phenolic compounds appear in petroleum refinery wastewater from several sources, such as the neutralized spent caustic waste streams, the tank water drain, the desalter effluent and the production unit. Therefore, effective treatments of such wastewaters are crucial. Conventional techniques used to treat these wastewaters pose several drawbacks, such as incomplete or low efficient removal of phenols. Recently, biocatalysts have attracted much attention for the sustainable and effective removal of toxic chemicals like phenols from wastewaters. The advantages of biocatalytic processes over the conventional treatment methods are their ability to operate over a wide range of operating conditions, low consumption of oxidants, simpler process control, and no delays or shock loading effects associated with the start-up/shutdown of the plant. Among different biocatalysts, oxidoreductases (i.e., tyrosinase, laccase and horseradish peroxidase) are known as green catalysts with massive potentialities to sustainably tackle phenolic contaminants of high concerns. Such enzymes mainly catalyze the o-hydroxylation of a broad spectrum of environmentally related contaminants into their corresponding o-diphenols. This review covers the latest advancement regarding the exploitation of these enzymes for sustainable oxidation of phenolic compounds in wastewater, and suggests a way forward.

scholarly journals Activated biochars derived from wood biomass liquefaction residues for effective removal of hazardous hexavalent chromium from aquatic environments

GCB Bioenergy ◽  
2021 ◽  
Author(s):  
Dominika Janiszewska ◽  
Rafał Olchowski ◽  
Aldona Nowicka ◽  
Magdalena Zborowska ◽  
Krzysztof Marszałkiewicz ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Aquatic Environments ◽  
Wood Biomass ◽  
Effective Removal
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