scholarly journals Synthesis and Application of FeCu Bimetallic Nanoparticles in Coal Mine Wastewater Treatment

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 132
Author(s):  
Nkosinathi Goodman Dlamini ◽  
Albertus Kotze Basson ◽  
Viswanadha Srirama Rajasekhar Pullabhotla

Wastewater treatment has become a global challenge with wastewater treatment cost fast increasing. Industrial processes such as downstream processes, wastewater treatment, and several fermentation processes depend largely on the use of flocculants. Synthetic flocculants, which are conventionally used in wastewater treatment, are hazardous to the environment and are carcinogenic to human health. Therefore, bioflocculants can be used as an alternative due to their biodegradable and environmentally friendly nature. However, low efficacy hinders their industrial application. This necessitates the need for a new technology to combat wastewater treatment challenges. Nanotechnology provides the platform to explore the possible solutions to these problems. The combination of two different metals results in the formation of bimetallic nanoparticles (BNPs). Due to better properties, bimetallic nanoparticles have attracted huge attention as compared to monometallic nanoparticles from both technological and scientific views. Iron copper bimetallic nanoparticles (FeCu BNPs) were successfully stabilized by bioflocculant and used in the coal mine wastewater treatment. Infrared spectrometric analysis showed the presence of carboxyl (COO−), hydroxyl (−OH), and amino (−NH2) functional groups. SEM images showed irregular and crystalline like morphology. Meanwhile, TEM analysis revealed chain like agglomerated nanoparticles. FeCu BNPs exhibited a wide pH stability range from 3, 7, and 11 with 99% flocculation activity at pH 7 and at lowest dosage of 0.2 mg/mL. After treating wastewater, the FeCu BNPs could remove pollutants such as phosphate, sulfate, calcium, chemical oxygen demand (COD), and biological oxygen demand (BOD) with phosphate having the highest removal efficacy of 99%.

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2689 ◽  
Author(s):  
Zayed Abu Tawila ◽  
Salmah Ismail ◽  
Arezoo Dadrasnia ◽  
Mohammed Usman

The production, optimization, and characterization of the bioflocculant QZ-7 synthesized by a novel Bacillus salmalaya strain 139SI isolated from a private farm soil in Selangor, Malaysia, are reported. The flocculating activity of bioflocculant QZ-7 present in the selected strain was found to be 83.3%. The optimal culture for flocculant production was achieved after cultivation at 35.5 °C for 72 h at pH 7 ± 0.2, with an inoculum size of 5% (v/v) and sucrose and yeast extract as carbon and nitrogen sources. The maximum flocculating activity was found to be 92.6%. Chemical analysis revealed that the pure bioflocculant consisted of 79.08% carbohydrates and 15.4% proteins. The average molecular weight of the bioflocculant was calculated to be 5.13 × 105 Da. Infrared spectrometric analysis showed the presence of carboxyl (COO-), hydroxyl (-OH), and amino (-NH2) groups, polysaccharides and proteins. The bioflocculant QZ-7 exhibited a wide pH stability range from 4 to 7, with a flocculation activity of 85% at pH 7 ± 0.2. In addition, QZ-7 was thermally stable and retained more than 80% of its flocculating activity after being heated at 80 °C for 30 min. SEM analysis revealed that QZ-7 exhibited a clear crystalline brick-shaped structure. After treating wastewater, the bioflocculant QZ-7 showed significant flocculation performance with a COD removal efficiency of 93%, whereas a BOD removal efficiency of 92.4% was observed in the B. salmalaya strain 139SI. These values indicate the promising applications of the bioflocculant QZ-7 in wastewater treatment.


2018 ◽  
Vol 77 (7) ◽  
pp. 1909-1919
Author(s):  
Penghui Gao ◽  
Meng Zhang ◽  
Yuji Du ◽  
Bo Cheng ◽  
Donghai Zhang

Abstract Water is important resource for human survival and development. Coal mine wastewater (CMW) is a byproduct of the process of coal mining, which is about 7.0 × 1010 m3 in China in 2016. Considering coal mine wastewater includes different ingredients, a new bubble column humidification and dehumidification system is proposed for CMW treatment. The system is mainly composed of a bubble column humidification and dehumidification unit, solar collector, fan and water tank, in which air is used as a circulating medium. The system can avoid water treatment component blocking for reverse osmosis (RO) and multi effect distillation (MED) dealing with CMW, and produce water greenly. By analysis of heat and mass transfer, the effects of solar radiation, air bubble velocity and mine water temperature on water treatment production characteristics are studied. Compared with other methods, thermal energy consumption (TEC) of bubble column humidification and dehumidification (BCHD) is moderate, which is about 700 kJ/kg (powered by solar energy). The results would provide a new method for CMW treatment and insights into the efficient coal wastewater treatment, besides, it helps to identify the parameters for the technology development in mine water treatment.


2021 ◽  
Author(s):  
Zuzingcebo Goldern Ntombela ◽  
AK Basson ◽  
E Madoroba ◽  
VSR Pullabhotla

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.


2019 ◽  
Vol 80 (12) ◽  
pp. 2310-2319 ◽  
Author(s):  
Prashant Dhanke ◽  
Sameer Wagh ◽  
Abhijeet Patil

Abstract Water generated from the fish processing industry is contaminated with organic matter. This organic matter present in wastewater increases the biochemical oxygen demand (BOD) and chemical oxygen demand (COD). A new technology, hydrodynamic cavitation (HC) is used to deal with this wastewater produced in fish processing plants. The orifice plate is used in the HC reactor to generate a cavitation effect. The intensification of this technique was carried out with the help of hydrogen peroxide (H2O2) and TiO2. The treatment of this wastewater is reported in terms of percent degradation in BOD and COD and in biodegradability index (BI). Operating parameters like inlet pressure, pH, operating temperature and H2O2 doses were used to find the optimum condition. 15 g/L of H2O2 gave 69.5% reduction of COD in the 120 min of treatment that also increases BI value to 0.93 at inlet pressure 8 bar, Plate-5, temperature (30 °C), and pH 4. In the ultrasonic cavitation (UC) reactor, COD reduction is 68.7% without TiO2 and with TiO2 it is 71.2%. Also, this HC and UC reactor reduced CFU count to a great extent at the same operating conditions.


2020 ◽  
Vol 11 (1) ◽  
pp. 174
Author(s):  
Konstantinos P. Papadopoulos ◽  
Christina N. Economou ◽  
Athanasia G. Tekerlekopoulou ◽  
Dimitris V. Vayenas

Algal/cyanobacterial biofilm photobioreactors provide an alternative technology to conventional photosynthetic systems for wastewater treatment based on high biomass production and easy biomass harvesting at low cost. This study introduces a novel cyanobacteria-based biofilm photobioreactor and assesses its performance in post-treatment of brewery wastewater and biomass production. Two different supporting materials (glass/polyurethane) were tested to investigate the effect of surface hydrophobicity on biomass attachment and overall reactor performance. The reactor exhibited high removal efficiency (over 65%) of the wastewater’s pollutants (chemical oxygen demand, nitrate, nitrite, ammonium, orthophosphate, and total Kjeldahl nitrogen), while biomass per reactor surface reached 13.1 and 12.8 g·m−2 corresponding to 406 and 392 mg·L−1 for glass and polyurethane, respectively, after 15 days of cultivation. The hydrophilic glass surface favored initial biomass adhesion, although eventually both materials yielded complete biomass attachment, highlighting that cell-to-cell interactions are the dominant adhesion mechanism in mature biofilms. It was also found that the biofilm accumulated up to 61% of its dry weight in carbohydrates at the end of cultivation, thus making the produced biomass a suitable feedstock for bioethanol production.


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