2024-03-28T09:14:38Zhttps://uir.unisa.ac.za/oai/requestoai:uir.unisa.ac.za:10500/258572019-10-15T12:03:29Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Congo Red Dye Removal by Direct Membrane Distillation using PVDF/PTFE Membrane
Mamba, B.B.
Khumalo, Nonhlanhla P
Nthunya, Lebea N.
De Cank, E
Deres, S
Verliefde, A.R.D.
Kuvarega, A.T.
Mhlanga, Sabelo D.
Dlamini, D.S.
Congo red dye
Methyl Fictionalized silica nano particles
PVDF/PTFE nanocomposite membranes
Direct contact membrane distillation
Follow the DOI link at the top of the record to access the full-text of the article on the publisher's web site
The ability to use the membrane distillation (MD) technique is envisaged as a promising approach to attain sustainable and reliable clean water supply. In this work, polytetrafluoroethylene/polyvinylidene fluoride (PVDF/PTFE) flat sheet membranes were fabricated via the thermally induced solvent evaporation process. The PVDF/PTFE membrane surface was modified by incorporating methyl functionalized mesoporous silica nanoparticles (MfSNPs). Prior to application, the membranes were characterized with respect to surface and structural morphology, hydrophobicity and overall porosity. Clean water flux measurements were conducted using a direct contact membrane distillation (DCMD) lab-scale experimental setup with deionized water as the feed solution (50 °C) and permeate solution (20 °C). The highest stable pure water flux for the MfSNPS/PVDF/PTFE membranes was 0.0041 L/h m2. The incorporation of the MfNPS did not only improve the fluxes but also induced low wetting properties as shown by the contact angle and LEPw values. The MfSNPs/PVDF/PTFE membranes were highly efficient in removing Congo red dye from water with 99% removal efficiency achieved.
2019-10-15T12:00:00Z
2019-10-15T12:00:00Z
2018-03-18
Article
N.P. Khumalo, L.N. Nthunya, E. De Canck, S. Derese, A.R. Verliefde, A.T. Kuvarega, B.B. Mamba, S.D. Mhlanga, D.S. Dlamini,(2018).Congo red dye removal by direct membrane distillation using PVDF/PTFE membrane. Seperation and Purification Technology, 211, 578-586.
1383-5866
https://doi.org/10.1016/j.seppur.2018.10.039
http://hdl.handle.net/10500/25857
en
Elsevier
oai:uir.unisa.ac.za:10500/258682020-02-10T07:19:14Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Exploring the supply chain coordination dimensions for Artemisinin-based combination therapies in Uganda
Nagitta, Oluka Pross
Mkansi, Marcia
Supply chain, coordination, dimensions artemisinin-based combination therapies, availability
The aim of the study was to explore how the logistics, micro, market and macro coordination dimensions affect the availability of artemisinin-based combination therapies (ACTs) in general hospitals in Uganda. Following a qualitative approach, a multiple case study strategy was used. Specifically, four focus group discussions, each consisting of 8 respondents were conducted from four purposively selected hospitals. The respondents were selected using simple random sampling from representatives of the Drug Therapeutic Management Committee (DTMC) for the purpose of exploring the supply chain coordination. Thereafter, cross-case analysis was done to identify the key coordination mechanisms that could be incorporated into the existing framework. A number of coordination dimensions were identified from the focus group discussions and regrouped using hierarchical coding scheme. Whilst the study’s findings on micro dimensions and logistics dimensions are in accordance with previous scholars, the market and macro dimensions reveal valuable insight into the dimensions necessary for supply chain coordination of ACTs. Market dimensions such as joint training, monitoring and quarterly meetings with key stakeholders are highly regarded for enhancing better coordination of ACTs. The macro coordination dimensions such as verification of ACTs, policies, and regulation are enablers, yet political interference, poverty and donor funding, culture, and lack of appropriate technology affect the availability of ACTs. The novelty of this study is that it adopts a holistic approach to the supply chain coordination of multi-embedded distribution system and extends insight of coordination framework to include the market and macro dimensions that reflect practice.
2019-10-16T13:17:49Z
2019-10-16T13:17:49Z
2019
Article
Nagitta, O. P. and Mkansi, M. 2019. Exploring the supply chain coordination dimensions for Artemisinin-based combination therapies in Uganda. International Journal of Supply Chain Management, 8 (4): 134-151.
2050-7399
http://hdl.handle.net/10500/25868
en
ExcelingTech Pub, UK
oai:uir.unisa.ac.za:10500/258712019-10-22T09:37:45Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Critical review of montmorillonite/polymer mixed-matrix filtration membranes: Possibilities and challenges
Mamba, Bheki B
Li, Jianxin.
Dlamini, D.S.
Mixed-matrix membrane
Clay
Desalination
Exfoliated
Phase inversion
Follow the DOI link at the top of the record to access the full-text of this article on the publisher's web-site
This paper reviews the literature on clay/polymer (CP) based mixed-matrix membranes (MMM) for water treatment. Clay minerals have been credited for ultrafiltration (UF) membranes behaving like nanofiltration (NF) membranes in terms of salt rejection through the repulsion mechanism. This is interesting and more attention should be focused on this approach. There is an apparent agreement in the literature that the observed increase and then decrease in water flux with an increase in clay mineral loading is a result of viscosity changes in the casting solution. While this is true, there is still a need for studies that will consider that the clay mineral sheets are much larger compared to water molecules and are impermeable; hence, at higher loading they may impede water flow. Exfoliated clay platelets are basically similar to graphene oxide, which has gained significant attention lately in water treatment studies; however, to date, there is no information on the effect of the delaminated structures on the performance of available CP membranes.
2019-10-16T14:03:46Z
2019-10-16T14:03:46Z
2019-02
Article
Mamba Bheki B, Li Jianxin, Dlamini Derrick.(2019).Critical review of montmorillonite/polymer mixed-matrix filtration membranes: Possibilities and challenges.Applied Clay Science, Vol: 168, Page: 21-30
0169-1317
https://doi.org/10.1016/j.clay.2018.10.016
http://hdl.handle.net/10500/25871
en
Elsevier BV
oai:uir.unisa.ac.za:10500/262152020-03-18T09:50:03Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Phytosynthesis of BiVO4 nanorods using Hyphaene thebaica for diverse biomedical applications
Mohamed, Hamza E. A.
Afridi, Shakeeb
Khalil, Ali T
Zohra, Tanzeel
Alam, Muhammad M
Ikram, Aamir
Shinwari, Zabta K
Maaza, Malik
Abstract
Biosynthesis of bismuth vanadate (BiVO4) nanorods was performed using dried fruit extracts of Hyphaene thebaica as a cost effective reducing and stabilizing agent. XRD, DRS, FTIR, zeta potential, Raman, HR-SEM, HR-TEM, EDS and SAED were used to study the main physical properties while the biological properties were established by performing diverse assays. The zeta potential is reported as − 5.21 mV. FTIR indicated Bi–O and V–O vibrations at 640 cm−1 and 700 cm−1/1120 cm−1. Characteristic Raman modes were observed at 166 cm−1, 325 cm−1 and 787 cm−1. High resolution scanning and transmission electron micrographs revealed a rod like morphology of the BiVO4. Bacillus subtilis, Klebsiella pneumonia, Fusarium solani indicated highest susceptibility to the different doses of BiVO4 nanorods. Significant protein kinase inhibition is reported for BiVO4 nanorods which suggests their potential anticancer properties. The nanorods revealed good DPPH free radical scavenging potential (48%) at 400 µg/mL while total antioxidant capacity of 59.8 µg AAE/mg was revealed at 400 µg/mL. No antiviral activity is reported on sabin like polio virus. Overall excellent biological properties are reported. We have shown that green synthesis can replace well established processes for synthesizing BiVO4 nanorods.
2020-01-01T04:36:55Z
2020-01-01T04:36:55Z
2019-12-12
2020-01-01T04:36:56Z
Article
AMB Express. 2019 Dec 12;9(1):200
https://doi.org/10.1186/s13568-019-0923-1
http://hdl.handle.net/10500/26215
en
The Author(s)
oai:uir.unisa.ac.za:10500/251982019-10-22T09:31:04Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Removal of dissolved organic matter from raw water using zero valent iron
Chaukura, Nhamo.
Moyo, Welldone.
Mamba, Bhekie B.
Nkambule, Thabo I.
Emerging organic pollutants
Nanocomposite
Natural organic matter
Waste polystyrene
Please follow the DOI link at the top of this record to access the full-text on the publisher's website
There are a limited number of potentially scalable low-cost treatment methods for removing organic pollutants
in water. In this study, a magnetic zero valent iron-carbonaceous conjugated microporous polymer nanocomposite
(ZVI-CCMP) was synthesized from ZVI and waste polystyrene via the liquid phase reduction method,
and used in a batch system for the removal of dissolved organic carbon (DOC) in water from a water treatment
plant (WTP) in Pretoria, South Africa. The results were compared to the DOC removal efficiency of the WTP. The
surface morphology of the nanocomposites as characterized using scanning electron microscopy showed heterogeneous
ZVI nanastructures dispersed on the CCMP surface. Fourier transform infrared spectroscopy showed
that the functional groups on the ZVI-CCMP surface were predominantly C]C and C-C from quinonoid motifs,
aliphatic chain conjugation, and C-S groups originating from the introduced sulphonic moieties. Batch experiment
data indicated that ZVI-CCMP adsorbed significantly (p=0.01) more DOC than ZVI, demonstrating the
synergistic effect of ZVI activation. Whereas the WTP removed up to 24.3% DOC, ZVI and ZVI-CCMP removed 64
and 75%, respectively after a contact time of 30 min. Thus, compared to the processes used by the WTP, batch
experiments using ZVI and ZVI-CCMP were 41 (p=0.00) and 52% (p=0.01) superior, respectively, demonstrating
the potential of these materials to be upscaled for pilot and real life applications. While polystyrene has
been used in the ZVI composites and the synthesis and evaluation of ZVI decorated carbon based materials has
been widely studied, ZVI-CCMP based materials have not been reported. The objectives were: (1) to synthesise
and characterise ZVI-CCMP nanocomposites; (2) to evaluate the removal of DOC in real water samples by ZVI
and ZVI-CCMP; and (3) to compare the relative efficiency of ZVI-CCMP to that of the water treatment process
through the measurement of DOC. Using CCMP nanocomposites to treat water is potentially a low-cost and
environmentally friendly alternative for reducing the adverse public health and environmental risks associated
with waste polystyrene.
2019-01-22T11:42:04Z
2019-01-22T11:42:04Z
2018
Article
Nhamo Chaukura, Welldone Moyo, Bhekie B. Mamba, Thabo I. Nkambule (2018) Removal of dissolved organic matter from raw water using zero valent iron.Physics and Chemistry of the Earth 107 (2018) 38–44
1474-7065
https://doi.org/10.1016/j.pce.2018.08.006
http://hdl.handle.net/10500/25198
en
Elsevier
oai:uir.unisa.ac.za:10500/252992020-03-18T13:40:31Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Computational and experimental study for the desalination of petrochemical industrial effluents using direct contact membrane distillation
Osman, Muhammad S
Masindi, Vhahangwele
Abu-Mahfouz, Adnan M
Abstract
The petrochemical, mining and power industries have reacted to the recent South African water crisis by focussing on improved brine treatment for water and salt recovery with the aim of achieving zero liquid effluent discharge. The purpose of this novel study was to compare experimentally obtained results from the treatment of synthetic NaCl solutions and petrochemical industrial brines such as spent ion exchange regenerant brines and reverse osmosis (RO) brines to the classical well-known Knudsen diffusion, molecular diffusion and transition predictive models. The predictive models were numerically solved using a developed mathematical algorithm that was coded using MATLAB® software. The impact of experimentally varying the inlet feed temperature on process performance of the system is presented here and compared to simulated results. It was found that there was good agreement between the experimentally obtained results, for both the synthetic NaCl solution and the industrial brines. The mean average percentage error (MAPE) was found to be 7.9% for the synthetic NaCl solutions when compared to the Knudsen model. The Knudsen/molecular diffusion transition theoretical model best predicted the performance of the membrane for the industrial spent ion exchange regenerant brine with a mean absolute percentage error (MAPE) of 13.3%. The Knudsen model best predicted the performance of the membrane (MAPE of 10.5%) for the industrial RO brine. Overall, the models were able to successfully predict the water flux and can be used as potential process design tools.
2019-03-01T06:07:07Z
2019-03-01T06:07:07Z
2019-02-22
2019-03-01T06:07:07Z
Journal Article
Applied Water Science. 2019 Feb 22;9(2):29
https://doi.org/10.1007/s13201-019-0910-3
http://hdl.handle.net/10500/25299
en
The Author(s)
oai:uir.unisa.ac.za:10500/235742019-10-22T09:23:55Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Abatement of humic acid from aqueous solution using a carbonaceous conjugated microporous polymer derived from waste polystyrene
Chaukura, Nhamo
Moyo, Welldone
Mamba, B.B.
Nkambule, Thabo L.
Conjugated microporous polymer
Natural organic matter
Pollution
Sorption
Humic acid (HA) is a major constituent of natural organic matter (NOM) found in water systems. Although NOM generally does not have any known harmful effects to humans, it imparts repulsive organoleptic properties to water, reacts with disinfectants to produce toxic products, and interferes with the efficiency of water treatment processes. The removal of NOM and related compounds from water is therefore important to render water potable and suitable for other applications. In this work, a hitherto unreported carbonaceous conjugated microporous polymer (CCMP) prepared through the organic-polymeric-precursor-controlled carbonization of hypercrosslinked post-consumer waste polystyrene (WPS) was evaluated for its capacity to remove HA from synthetic wastewater. This advanced material retained the morphology of the precursor material, while its porosity and chemical integrity were significantly improved. The approach is an environmentally friendly way of handling WPS while at the same time remediating NOM-contaminated water. Overall, with a maximum adsorption capacity of 340 mg/g in batch experiments, and a maximum initial removal rate of 95.7% in column experiments, the results showed that CCMP can be used for the remediation of HA-contaminated water at high pH.
2018-01-31T09:38:05Z
2018-01-31T09:38:05Z
2017
Article
Chaukura, N., Moyo, W., Mamba, B.B. et al. Environ Sci Pollut Res (2017). https://doi.org/10.1007/s11356-017-0691-x
1614-7499
https://doi.org/10.1007/s11356-017-0691-x
http://hdl.handle.net/10500/23574
Afrikaans
© Springer-Verlag GmbH Germany, part of Springer Nature
oai:uir.unisa.ac.za:10500/284212022-03-31T10:58:44Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Continuous Fabrication of Ti3C2Tx MXene-Based Braided Coaxial Zinc-Ion Hybrid Supercapacitors with Improved Performance
Shi, Bao
Li, La
Chen, Aibing
Jen, Tien-Chien
Liu, Xinying
Shen, Guozhen
Highlights
Ti3C2Tx MXene-based coaxial zinc-ion hybrid fiber supercapacitors (FSCs) were fabricated with braided structure, which can be prepared continuously and present excellent flexibility and ultrastability.
A sports watch driven by the watch belts which weaved uses the obtained zinc-ion hybrid FSC and LED arrays lighted by the FSCs under embedding into textiles, demonstrating the great potential application in smart wearable textiles.
Abstract
Zinc-ion hybrid fiber supercapacitors (FSCs) are promising energy storages for wearable electronics owing to their high energy density, good flexibility, and weavability. However, it is still a critical challenge to optimize the structure of the designed FSC to improve energy density and realize the continuous fabrication of super-long FSCs. Herein, we propose a braided coaxial zinc-ion hybrid FSC with several meters of Ti3C2Tx MXene cathode as core electrodes, and shell zinc fiber anode was braided on the surface of the Ti3C2Tx MXene fibers across the solid electrolytes. According to the simulated results using ANSYS Maxwell software, the braided structures revealed a higher capacitance compared to the spring-like structures. The resulting FSCs exhibited a high areal capacitance of 214 mF cm–2, the energy density of 42.8 μWh cm−2 at 5 mV s−1, and excellent cycling stability with 83.58% capacity retention after 5000 cycles. The coaxial FSC was tied several kinds of knots, proving a shape-controllable fiber energy storage. Furthermore, the knitted FSC showed superior stability and weavability, which can be woven into watch belts or embedded into textiles to power smart watches and LED arrays for a few days.
2022-01-01T05:19:34Z
2022-01-01T05:19:34Z
2021-12-15
2022-01-01T05:19:34Z
Journal Article
Nano-Micro Letters. 2021 Dec 15;14(1):34
https://doi.org/10.1007/s40820-021-00757-6
https://hdl.handle.net/10500/28421
en
The Author(s)
oai:uir.unisa.ac.za:10500/214782022-05-31T06:43:27Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Adsorption behaviour of Ethylene Vinyl Acetate and Polycaprolactone-Bentonite Composites for Pb 2+ Uptake
Dlamini, D. S.
Mishra, A. K.
Mamba, B. B.
2016-09-19T11:25:48Z
2016-09-19T11:25:48Z
2012
Article
Dlamini, D.S., Mishra, A.K., Mamba, B.B (2012) Adsorption Behaviour of Ethylene Vinyl Acetate and Polycaprolactone-Bentonite Composites for Pb 2+ Uptake. Journal of Inorganic and Organometallic Polymers and Materials 22(2) pp 342-351
DOI10.1007/s10904-011-9640-1
EID2-s2.0-84857997982
https://www.scopus.com/inward/record.uri?eid=2-s2.0-84857997982&partnerID=40&md5=7f4da4c3b53c108b75ec300cc760e07c
http://hdl.handle.net/10500/21478
oai:uir.unisa.ac.za:10500/263442020-03-17T12:13:47Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Chitosan-lignin-titania nanocomposites for the removal of brilliant black dye from aqueous solution
Masilompane, Thato
Chaukura, Nhamo.
Bhardwaj Mishra, Shivani
Mishra, Ajay Kumar
Chitosan-lignin-titania
Brilliant black dye
Nanoadsorbent
A nanoadsorbent was synthesized from kraft lignin derived from paper and pulp black liquor, chitosan, and titania (TiO2) and used to remove Brilliant Black dye (BB) from aqueous solution. Transmission electron microscopy measurements confirmed the material was nanoscale and BET studies showed a pore width of 11.36 nm with a BET surface area (SBET) of 10.75 m2/g. The presence of NH, O and TiO functional groups was confirmed by ATR-FTIR, and thermogravimetric analysis indicated the nanoadsorbent was thermally stable up to 300 °C. Scanning electron microscopy showed that lignin had larger particles with well-defined edges, while the surface morphology of chitosan showed non-uniform, short fibrous microstructures. The diffraction patterns of the nanocomposite showed a polycrystalline anatase phase and selected area electron diffraction analysis showed the nanocomposite has small spots making up a ring, indicating the nanoparticles has a crystalline structure. The effects of contact time, solution pH, adsorbent dosage, and initial dye concentration on the adsorption of BB were investigated. The batch adsorption data obeyed the Freundlich isotherm (r2 = 0.91), and the monolayer adsorption capacities calculated using the linear Langmuir isotherm was 15.8 mg/g at 25 °C. The adsorption kinetic data were described by the pseudo-second order kinetic model (r2 = 0.93).
2020-03-17T12:03:29Z
2020-03-17T12:03:29Z
2018-12
Article
Magdeline, Thato & Chaukura, Nhamo & Mishra, Shivani & Mishra, Ajay. (2018). Chitosan-lignin-titania nanocomposites for the removal of brilliant black dye from aqueous solution. International Journal of Biological Macromolecules. 120. 1659-1666.10.1016/j.ijbiomac.2018.09.129.
https://doi.org/10.1016/j.ijbiomac.2018.09.129
http://hdl.handle.net/10500/26344
en
Elsevier
oai:uir.unisa.ac.za:10500/298322023-06-13T09:59:15Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Magnetite-impregnated biochar of parthenium hysterophorus for adsorption of Cr(VI) from tannery industrial wastewater
Fito, Jemal
Abewaa, Mikiyas
Nkambule, Thabo
Abstract
The tannery industry inevitably generates toxic and catastrophic wastewater, which results in a huge threat to public health and water resources. Therefore, this work aimed to synthesize parthenium hysterophorus-based biochar–Fe3O4 composite for removal of Cr(VI) from tannery wastewater under 34 full factorial experimental designs of the Box–Behnken, which was analyzed using response surface methodology under four independent factors of pH (3, 6, and 9), initial Cr(VI) concentrations (40, 70, and 100 mg/L), contact times (30, 60, and 90 min), and adsorbent doses (20, 60, and 100 mg/100 mL). This composite adsorbent was described by a high BET surface area of 237.4 m2/g, XRD prominent peaks, SEM morphology corroborate and FTIR multifunctionalities of O–H at 3296 cm−1, the vibration of ketone C–OH at 1240 cm−1, and the vibration of C–O–C at 1147 cm−1 and Fe–O stretching at 542 cm−1. The maximum Cr(IV) removal efficiency of 91.8% was recorded at an initial Cr(VI) concentration of 40 mg/L, pH of 3, adsorbent dose of 100 mg/100 mL, and a contact time of 90 min, whereas the minimum Cr(VI) removal of 17.3% was observed at an initial Cr(VI) concentration of 100 mg/L, 20 mg/100 mL of adsorbent dose, pH of 9, and contact time of 30 min. The concentration of Cr(VI) in real wastewater was determined to be 85.13 mg/L and its remediation was found to be 81.8%. Langmuir’s model was the best fit with experimental data at R2 0.99 and qmax 400 mg/g, showing that the adsorption process was homogenous and monolayer. In conclusion, the adsorption results were encouraging, and biochar–Fe3O4 appears to be a potential candidate for Cr removal from wastewater.
2023-03-01T04:47:40Z
2023-03-01T04:47:40Z
2023-02-09
2023-03-01T04:47:40Z
Journal Article
Applied Water Science. 2023 Feb 09;13(3):78
https://doi.org/10.1007/s13201-023-01880-y
https://hdl.handle.net/10500/29832
en
The Author(s)
oai:uir.unisa.ac.za:10500/272252021-06-23T15:56:17Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Plant active products and emerging interventions in water potabilisation: disinfection and multi-drug resistant pathogen treatment
Adeeyo, Adeyemi O
Edokpayi, Joshua N
Alabi, Mercy A
Msagati, Titus A M
Odiyo, John O
Abstract
Background
This review aims at establishing the emerging applications of phytobiotics in water treatment and disinfection.
Results
Statistical analysis of data obtained revealed that the use of plant product in water treatment needs more research attention. A major observation is that plants possess multifaceted components and can be sustainably developed into products for water treatment. The seed (24.53%), flower (20.75), leaf (16.98%) and fruit (11.32%) biomasses are preferred against bulb (3.77%), resin (1.89%), bark (1.89%) and tuber (1.89%). The observation suggests that novel applications of plant in water treatment need further exploration since vast and broader antimicrobial activities (63.63%) is reported than water treatment application (36.37%).
Conclusions
This review has revealed the existing knowledge gaps in exploration of plant resources for water treatment and product development. Chemical complexity of some plant extracts, lack of standardisation, slow working rate, poor water solubility, extraction and purification complexities are limitations that need to be overcome for industrial adoption of phytochemicals in water treatment. The field of phytobiotics should engage modern methodologies such as proteomics, genomics, and metabolomics to minimise challenges confronting phytobiotic standardisation. The knowledge disseminated awaits novel application for plant product development in water treatment.
2021-04-01T05:01:04Z
2021-04-01T05:01:04Z
2021-03-24
2021-04-01T05:01:04Z
Journal Article
Clinical Phytoscience. 2021 Mar 24;7(1):31
https://doi.org/10.1186/s40816-021-00258-4
http://hdl.handle.net/10500/27225
en
The Author(s)
oai:uir.unisa.ac.za:10500/214252022-08-19T06:32:31Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Artificial neural network simulations and experimental results: Removal of trichlorophenol from water using Chromolaena odorata stem
Dlamini, D.S.
Mishra, A.K.
Mamba, B.B.
Artificial neural network
Trichlorophenol
Water
Chromolaena
Odorata
Stem
2016-09-19T11:25:42Z
2016-09-19T11:25:42Z
2014
Article
Dlamini, D.S., Mishra, A.K., Mamba, B.B. 2014, "Artificial neural network simulations and experimental results: Removal of trichlorophenol from water using Chromolaena odorata stem", Water SA, vol. 40, no. 2, pp. 369-378.
DOI10.4314/wsa.v40i2.19
EID2-s2.0-84900024039
https://www.scopus.com/inward/record.uri?eid=2-s2.0-84900024039&partnerID=40&md5=6acfa7fdece149616a81bd13a167330b
http://hdl.handle.net/10500/21425
oai:uir.unisa.ac.za:10500/258672019-10-22T09:26:11Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Natural organic matter in aquatic systems–a South African perspective
Ndlangamandla, Nqobile G
Moyo, Welldone
Msagati, Titus A.M.
Mamba, Bheki B
Nkambule, Thabo T.I
Chaukura, Nhamo
advanced oxidation,
ceramic membranes
disinfection byproducts
treatability
water treatment
Natural organic matter (NOM) is a complex heterogeneous mixture of humic (HS) and non-humic substances which are widespread in the aquatic environment. Other constituents are amino acids, aliphatic and aromatic hydrocarbons containing oxygen, nitrogen and hydroxyl groups. It is the combination and proportions of these motifs which give NOM its overall polarity and reactivity. Its main origins include soils, residues of fauna and flora, microbial excrements and anthropogenic faecal loads, agriculture activities and urban landscapes. Due to the different origins of the precursor material and the extent of transformation it undergoes, the composition of NOM in different water bodies varies. Characterization methods for NOM can be divided into three broad categories namely: (i) direct measuring methods, which measure the amount of organic matter in the sample; (ii) spectrometric methods, which measure the amount of radiation absorbed and or released by chromophores; and (iii) fractionation methods, which separate NOM according to size and polarity. South Africa has 6 distinct water quality regions, and each region has a unique NOM character and quantity. Existing water treatment plants do not remove NOM to levels low enough to inhibit the formation of disinfection by-products (DBPs). Currently, research is focusing more on the use of alternative techniques for NOM removal; these include advanced oxidation processes (AOPs), nanomaterials, and ceramic membranes. While NOM is well studied in other parts of the world, to the best of our knowledge, there is no state-of-the-art investigation of the occurrence and removal of NOM in South African source waters. This review aims at (i) synthesizing literature on the nature, occurrence and ecological impact of NOM, (ii) evaluating the removal of NOM in the six different water quality regions of South Africa, and (iii) suggesting novel approaches that can be used to remove NOM in South Africa.
2019-10-16T13:17:30Z
2019-10-16T13:17:30Z
2018-05
Article
Ndlangamandla, Nqobile G.; Moyo, Welldone; Msagati, Titus A.M.; Mamba, Bheki B.; Nkambule, Thabo T.I; Chaukura, Nhamo (2018). Natural organic matter in aquatic systems – a South African perspective. Water SA Vol. 44 No. 4
1816-7950
DOI: https://doi.org/10.4314/wsa.v44i4.11
http://hdl.handle.net/10500/25867
en
Water Research Commission
oai:uir.unisa.ac.za:10500/272862022-03-31T11:52:18Zcom_10500_3752com_10500_21138com_10500_2910com_10500_128col_10500_3753col_10500_21139
Simultaneous electrochemical sensing of dihydroxy benzene isomers at cost-effective allura red polymeric film modified glassy carbon electrode
Ganesh, Pattan-Siddappa
Shimoga, Ganesh
Lee, Seok-Han
Kim, Sang-Youn
Ebenso, Eno E
Abstract
Background
A simple and simultaneous electrochemical sensing platform was fabricated by electropolymerization of allura red on glassy carbon electrode (GCE) for the interference-free detection of dihydroxy benzene isomers.
Methods
The modified working electrode was characterized by electrochemical and field emission scanning electron microscopy methods. The modified electrode showed excellent electrocatalytic activity for the electrooxidation of catechol (CC) and hydroquinone (HQ) at physiological pH of 7.4 by cyclic voltammetric (CV) and differential pulse voltammetric (DPV) techniques.
Results
The effective split in the overlapped oxidation signal of CC and HQ was achieved in a binary mixture with peak to peak separation of 0.102 V and 0.103 V by CV and DPV techniques. The electrode kinetics was found to be adsorption-controlled. The oxidation potential directly depends on the pH of the buffer solution, and it witnessed the transfer of equal number of protons and electrons in the redox phenomenon.
Conclusions
The limit of detection (LOD) for CC and HQ was calculated to be 0.126 μM and 0.132 μM in the linear range of 0 to 80.0 μM and 0 to 110.0 μM, respectively, by ultra-sensitive DPV technique. The practical applicability of the proposed sensor was evaluated for tap water sample analysis, and good recovery rates were observed.
Graphical abstract
Electrocatalytic interaction of ALR/GCE with dihydroxy benzene isomers.
2021-05-01T03:23:09Z
2021-05-01T03:23:09Z
2021-04-20
2021-05-01T03:23:10Z
Journal Article
Journal of Analytical Science and Technology. 2021 Apr 20;12(1):20
https://doi.org/10.1186/s40543-021-00270-w
http://hdl.handle.net/10500/27286
en
The Author(s)