scholarly journals Maize Stalk Material for On-Site Treatment of Highly Polluted Leachate and Mine Wastewater

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 956
Author(s):  
Nicoleta Mirela Marin ◽  
Laurentiu Dinu ◽  
Ioana Stanculescu ◽  
Nicolae Ionut Cristea ◽  
Alexandra Ioana Ionescu
Keyword(s):  
Green Technology ◽  
Determination Limit ◽  
Metallic Ions ◽  
Metal Production ◽  
Batch Studies ◽  
Pilot Experiment ◽  
Polar Groups ◽  
Mine Wastewater ◽  
Wastewater Samples ◽  
New Research

New research applications involving the use of cellulosic material derived from maize stalk for on-site treatment of leachate were evaluated for specific removal of Cu(II) and Fe(III) from real, highly polluted tailing pond and mine wastewater samples. Two major issues generated by anthropic mining activities were also tackled: wastewater metal content decrease to improve water quality and subsequently metal specific recovery, increasing the economic efficiency of metal production by using a green technology for residual management. Rapid saturation of the maize stalk mass determined in batch studies and the mine pilot experiment led to diminished metal concentrations in the second pilot experiment, where Cu(II) and Pb(II) from synthetic solutions were monitored in order to test biomaterial performances. In addition, in the second pilot experiment, maize stalk removed Pb(II) in the first 36 h, below the determination limit of the analytical method. The biomaterial bed in the column was saturated after 252 h of inflow solution. FTIR-ATR, TG and SEM techniques probed the interaction between maize stalk polar groups C=O, –OH, C–O and tailing water metallic ions by large FTIR band displacements, intensity decrease and shape changes, modification of thermal stability and by changes in the appearance of adsorbent microstructure images owing mainly to ion exchange mechanism.

Application of Imprinted Functionalized Silica Gel Sorbent for Selective Removal of Cadmium (II) from Industial Wastewaters

2011 ◽  
Vol 213 ◽  
pp. 441-444 ◽  
Author(s):  
Zhan Chao Li ◽  
Hong Tao Fan ◽  
Ting Sun
Keyword(s):  
Silica Gel ◽  
Removal Rate ◽  
Sol Gel ◽  
Selective Removal ◽  
Synthetic Wastewater ◽  
Imprinted Polymer ◽  
Batch Studies ◽  
Ion Imprinted ◽  
Mine Wastewater ◽  
Efficient Adsorbent

This study investigated the application of an ion imprinted polymer (IIP) with (3-mercaptopropyl) trimethoxysilane (MPS) functionalized the surface of silica gel as a potential sorbent (IIP- MPS/SiO2) for the selective removal and recovery of Cd2+ from industrial wastewaters. IIP- MPS/SiO2 was prepared by a sol–gel method and characterized by IR. Batch studies were performed to evaluate the adsorption process and it was found that the sorbents were found to adsorb selectively Cd2+ in the presence of Co2+, Ni2+, Zn2+ and Cu2+ interferences in the same medium. IIP-MPS/SiO2 sorbent show the selectivity order under competitive conditions: Cd2+ > Co2+ > Ni2+ > Zn2+ > Cu2+. The removal rate of IIP- MPS/SiO2 sorbent for Cd2+ was about 80 % from synthetic wastewater and mine wastewater spiked with 10, 20 and 50 mg•L-1 Cd2+. This work proved that can IIP-MPS/SiO2 sorbent be used as an efficient adsorbent material for selective removal of Cd2+ from wastewaters.

Mechanism and Theory of Vulcanization

1948 ◽  
Vol 21 (2) ◽  
pp. 325-343 ◽  
Author(s):  
Robert D. Stiehler ◽  
James H. Wakelin
Keyword(s):  
Intermolecular Forces ◽  
Metallic Ions ◽  
X Ray ◽  
Vulcanized Rubber ◽  
Polar Groups ◽  
Rubber Vulcanizate ◽  
Strain Data ◽  
Metallic Compounds ◽  
Individual Existence ◽  
Reaction In Solution

Abstract x-Ray and stress-strain data have been obtained which indicate that accelerators and divalent metallic compounds, as well as sulfur, react with rubber molecules during vulcanization and become a part of the rubber vulcanizate. The vulcanization reaction was found to behave like a normal chemical reaction in solution, which is influenced by the temperature, solubilities of the reacting ingredients, relative strengths and concentrations of the acids present, pH, and chemical nature of the vulcanizing agent. On the basis of these results and the known characteristics of vulcanized rubber, the original hypothesis of Goodyear and the more recent conclusions of Midgley, Henne, and Shepard were developed into a theory of vulcanization which postulates that vulcanization is a process by which the intermolecular forces are increased through the introduction of polar groups, generally acidic in nature, into the rubber molecules. This is accomplished by the reaction of certain types of oxidizing agents with the alpha-methylene carbon atoms or double bonds. These intermolecular forces are further increased with soluble divalent metallic compounds by the formation of ionic valences between divalent metallic ions and polar acidic groups of the rubber vulcanizate. These divalent metallic ions may bridge the rubber molecules through ionic valences in the form of a salt. Intermolecular forces established during vulcanization give rigidity to the molecular structure, which retards plastic flow and crystallization of rubber molecules. They also are responsible for other characteristics of vulcanized rubber. The molecules in vulcanized rubber are presumably not joined by primary-valence bonds through sulfur or oxygen bridges, but retain their individual existence.

scholarly journals Designing of Fabric Reinforced Polymer in the Assessment of Sorption Capacity of Mussel Shell Powder for Divalent Ion: GIS Mapping and Statistical Studies

2021 ◽  
Author(s):  
S. Charulatha ◽  
K.S. Thangamani ◽  
N. Muthulaksmi Andal
Keyword(s):  
Fiber Reinforced Polymer ◽  
Synthetic Wastewater ◽  
Gis Mapping ◽  
Mollusc Shell ◽  
Batch Studies ◽  
Reinforced Polymer ◽  
Permissible Levels ◽  
Statistical Studies ◽  
Wastewater Samples ◽  
Shell Powder

Abstract This paper discusses the efficiency of acid modified mollusc shell powder in adsorbing Zn(II) ions from synthetic wastewater and actual wastewater samples discharged from electroplating industries. The chemically treated adsorbent was characterized in terms of structure and surface properties. The parameters such as, size of the sorbent particles, dosage, initial Zn(II) concentration, temperature, contact time pH and temperature were varied for optimization using batch studies. The adsorbate-adsorbent system was studied by Langmuir, Freundlich, Tempkin and DKR isotherms. The adsorption experiments were conducted in a column packed with the acid modified mollusc shell powder. Further, real wastewater samples having Zn(II) concentration higher than the permissible levels were collected from the industrial belt in Coimbatore, to assess the potential of the bio adsorbent. A fiber reinforced polymer fabricated with the adsorbent material installed at the effluent discharge plants achieved 100% Zn(II) removal from electroplating wastewaters. Statistical analysis performed using SPSS software showed significant correlation among the input parameters and the analytical results post-adsorption.

scholarly journals Biosafety and Removal Potential of Pollutants in Wastewater by the Microbial Flocculant from Marine Bacterium Obtained from Umlalazi Catchment, RSA

2021 ◽  
Author(s):  
Zuzingcebo Goldern Ntombela ◽  
AK Basson ◽  
E Madoroba ◽  
VSR Pullabhotla
Keyword(s):  
Coal Mine ◽  
Negative Impact ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Inhibitory Effect ◽  
Hydroxyl Group ◽  
Aquatic Life ◽  
Mine Wastewater ◽  
Wastewater Samples ◽  
Microbial Flocculant

Abstract Bioflocculants have been reported to be successfully used in the removal of pollutants and dye decolourization from wastewater as they (pollutants) have negative impact on both humans and aquatic life if not properly treated. Thus, the potential removal rate of a microbial flocculant produced by the marine bacterial strain of Bacillus safensis KX94275.1 from uMlalazi estuary, Mthunzini area, KZN for pollutants from wastewater samples and dyes from different dye solution was investigated. B. safensis produced a non-toxic microbial flocculant showed margin of safety in both breast cancer cells and normal cells with 87% and 96% cell survival after treatment with maximum dosage of bioflocculant solution of 100 µg/µL, respectively. Functional groups such as amino, carboxylic and hydroxyl group were revealed with FT-IR spectrum to be possessed by the microbial flocculant produced. Above 65% of microbial flocculant was attained when the flocculant was subjection to 700 oC using the thermogravimetric analyser. A produced bioflocculant was aqua-solvable and have no inhibitory effect in bacteria tested. This heat-stable and cation-dependent (Ba2+) bioflocculant removed more than 85% dye from different dye solutions, such as basic fuchsine (93%), congo red (87%), crystal violet (90%) and methylene blue (93%), using 0.4 mg/mL optimum dosage concentration at neutral pH. This wide pH (3-12) tolerant bioflocculant showed improvement on both domestic and coal mine wastewaters for the removal of biochemical oxygen demand with 66% and 99%, chemical oxygen demand with 48% and 93%, phosphate with 61% and 59%, total nitrogen with 69% and 68% and sulphide with 71% and 83% removal rate, respectively, and flocculation rate of 91% (domestic) and 95% (coal mine) wastewater. Thus, the application of the bioflocculant on wastewater treatment indicated the tremendous prospective in replacing risky traditional flocculating agents frequently utilized for purification of wastewater.

What is taken for granted in autism research?

2019 ◽  
Vol 42 ◽  
Author(s):  
Michele Ilana Friedner
Keyword(s):  
Research Methodologies ◽  
Communicative Practices ◽  
Autism Research ◽  
Autistic People ◽  
The Social ◽  
New Research

Abstract This commentary focuses on three points: the need to consider semiotic ideologies of both researchers and autistic people, questions of commensurability, and problems with “the social” as an analytical concept. It ends with a call for new research methodologies that are not deficit-based and that consider a broad range of linguistic and non-linguistic communicative practices.

Microscopic versus process parameters in heavy-oil upgrading

1992 ◽  
Vol 50 (1) ◽  
pp. 366-367
Author(s):  
V.A. Munoz ◽  
R.J. Mikula ◽  
C. Payette ◽  
W.W. Lam
Keyword(s):  
Molecular Weight ◽  
Liquid Fuels ◽  
Chemical Components ◽  
Heavy Oils ◽  
Synthetic Fuels ◽  
High Hydrogen ◽  
Optical Texture ◽  
Polar Groups ◽  
Anisotropic Character ◽  
Planar Molecules

The transformation of high molecular weight components present in heavy oils into useable liquid fuels requires their decomposition by means of a variety of processes. The low molecular weight species produced recombine under controlled conditions to generate synthetic fuels. However, an important fraction undergo further recombination into higher molecular weight components, leading to the formation of coke. The optical texture of the coke can be related to its originating components. Those with high sulfur and oxygen content tend to produce cokes with small optical texture or fine mosaic, whereas compounds with relatively high hydrogen content are likely to produce large optical texture or domains. In addition, the structure of the parent chemical components, planar or nonplanar, determines the isotropic or anisotropic character of the coke. Planar molecules have a tendency to align in an approximately parallel arrangement to initiate the formation of the nematic mesophase leading to the formation of anisotropic coke. Nonplanar highly alkylated compounds and/or those rich in polar groups form isotropic coke. The aliphatic branches produce steric hindrance to alignment, whereas the polar groups participate in cross-linking reactions.

The Need Inventory of Sensation Seeking (NISS)

2012 ◽  
Vol 28 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Marcus Roth ◽  
Philipp Hammelstein
Keyword(s):  
Sensation Seeking ◽  
Reliability And Validity ◽  
Assessment Method ◽  
Factorial Structure ◽  
Conventional Methods ◽  
New Research ◽  
Sensation Seeking Scale ◽  
Temperamental Trait ◽  
Nonclinical Study

Based on the conception of sensation seeking as a need rather than a temperamental trait ( Hammelstein, 2004 ), we present a new assessment method, the Need Inventory of Sensation Seeking (NISS), which is considered to assess a motivational disposition. Three studies are presented: The first examined the factorial structure and the reliability of the German versions of the NISS; the second study compared the German and the English versions of the NISS; and finally, the validity of the NISS was examined in a nonclinical study and compared to the validity of conventional methods of assessing sensation seeking (Sensation Seeking Scale – Form V; SSS-V). Compared to the SSS-V, the NISS shows better reliability and validity in addition to providing new research possibilities including application in experimental areas.

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