scholarly journals The proliferation rule of Microcystis aeruginosa under different initial pH conditions and its influence on the pH value of the environment

2021 ◽  
Author(s):  
Sijie Wei ◽  
Guanjie Zhuang ◽  
Lirijian Cheng ◽  
Shoubing Wang
Keyword(s):  
Microcystis Aeruginosa ◽  
Ph Value ◽  
Initial Ph ◽  
Ph Conditions

scholarly journals The Proliferation Rule of Microcystis Aeruginosa Under Different Initial pH Conditions and its Influence on the pH Value of the Environment

2021 ◽  
Author(s):  
Sijie Wei ◽  
Guanjie Zhuang ◽  
Lirijian Cheng ◽  
Shoubing Wang
Keyword(s):  
Microcystis Aeruginosa ◽  
Ph Value ◽  
Control Strategies ◽  
Scientific Basis ◽  
Cyanobacterial Blooms ◽  
Ph Values ◽  
Inoculation Density ◽  
Initial Ph ◽  
Ph Conditions ◽  
Optimal Ph

Abstract This study investigated the characteristics of the proliferation process of Microcystis aeruginosa and its changes to environmental pH values under different initial pH values and different initial inoculation densities. The results showed that although the initial pH value or the initial inoculation density was different, the pH values of the culture systems fluctuated up and down throughout the proliferation of M. aeruginosa, both on a daily and hourly time scale, and then tended to stabilize around the same value of 10.0 at the end of proliferation. The optimal pH value for the proliferation of M. aeruginosa was 9.56. This study creatively proposes that the period when the environmental pH value starts to rise rapidly toward 9.0 could be selected as an early warning period for a cyanobacterial outbreak, and the environmental pH value could be adjusted to below 8.0 to delay the outbreak. These results provide a scientific basis for further understanding the mechanism of cyanobacterial blooms and formulating pH-based control strategies.

scholarly journals Adsorption-Oxidation Mechanism of δ-MnO2 to Remove Methylene Blue

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Ge Yan ◽  
Pu Wang ◽  
Yuqian Li ◽  
Zhangjie Qin ◽  
Shuai Lan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Mechanism ◽  
Ph Value ◽  
Oxidation Mechanism ◽  
Superior Performance ◽  
Adsorption Ability ◽  
Initial Ph ◽  
Effects Of Ph ◽  
Ph Conditions ◽  
Positively Charged

The material, δ-MnO2, has exhibited superior performance on the removal of methylene blue (MB), but the process is significantly impacted by pH, and the impacting mechanism is still unclear. In this study, the effects of pH on the removal mechanism of MB using synthesized δ-MnO2 were investigated by distinguishing the adsorption and oxidation of MB by δ-MnO2 during the removal process in the dark. The results show that the total removal efficiency of MB by δ-MnO2 decreased significantly with an increase in the pH. MB could be removed by δ-MnO2 via an adsorption mechanism and oxidation mechanism, and the proportion of adsorptive removal and oxidative removal was different under different pH conditions. With an increase in the initial pH from 2.00 to 8.05, the redox potential of δ-MnO2 decreased, and its oxidation ability for the removal of MB also gradually decreased. In contrast, the surface negative charges of δ-MnO2 increased with an increase in the pH, and the adsorption ability towards positively charged MB also gradually increased. This indicates that the effects of pH on the removal of MB by δ-MnO2 are primarily dominated by its influence on the oxidation ability of δ-MnO2. In addition, it is further proved that the pH value has a significant effect on the oxidation and adsorption of MB on δ-MnO2. Moreover, the significant effects of pH on the oxidation of MB by δ-MnO2 are further demonstrated by observing the changes in Mn2+ and the UV-Vis spectra of intermediate products during the reaction, as well as the changes in the FTIR and XPS characterizations of δ-MnO2 after the reaction.

Study of Removing Bacteria and Microcystis aeruginosa by Hydroxyl Radical

2013 ◽  
Vol 864-867 ◽  
pp. 418-421
Author(s):  
Wei Xu ◽  
Rong Jie Yi ◽  
Jing Jing Li ◽  
Jin De Song ◽  
Chen Wu Yi ◽  
...  
Keyword(s):  
Hydroxyl Radical ◽  
Microcystis Aeruginosa ◽  
Large Scale ◽  
Microbial Contamination ◽  
Treatment Process ◽  
Treatment Time ◽  
Ph Value ◽  
High Concentration ◽  
Initial Ph ◽  
Strong Ionization Discharge

The 1.5t/h algae and bacteria wastewater with high concentration was treated by hydroxyl radical (OH) produced by a strong ionization discharge. In this paper, the feasibility of kill bacteria and alga by OH was investigated, and effects of OH concentration, treatment time and pollution initial concentration on degrading microorganisms by OH were investigated in detail. The results indicated that the treatment process was effective in the degradation of the bacteria and alga at the initial pH value of 7.1, OH dosage of 2.33mg/L, the initial microcystis aeruginosa concentration of 106/mL and the initial bacterial dosage of 106cfu/mL, the bacteria and alga degradation rate reached 99.99% at 303K after 15min treatment. The results provided a theoretical basis for the OH treatment of microbial contamination in drinking water in large-scale.

scholarly journals Hydrothermal Synthesis of Various Shape-Controlled Europium Hydroxides

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 529
Author(s):  
Hongjuan Zheng ◽  
Kongjun Zhu ◽  
Ayumu Onda ◽  
Kazumichi Yanagisawa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ph Value ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Hydrothermal Reactions ◽  
Starting Solution ◽  
Initial Ph ◽  
Shape Controlled ◽  
Scanning Electron

Eu(OH)3 with various shape-controlled morphologies and size, such as plate, rod, tube, prism and nanoparticles was successfully synthesized through simple hydrothermal reactions. The products were characterized by XRD (X-Ray Powder Diffraction), FE-SEM (Field Emission- Scanning Electron Microscopy) and TG (Thermogravimetry). The influence of the initial pH value of the starting solution and reaction temperature on the crystalline phase and morphology of the hydrothermal products was investigated. A possible formation process to control morphologies and size of europium products by changing the hydrothermal temperature and initial pH value of the starting solution was proposed.

scholarly journals The sorption of inorganic arsenic on modified sepiolite: Effect of hydrated iron(III)-oxide

2014 ◽  
Vol 79 (7) ◽  
pp. 815-828 ◽  
Author(s):  
Nikola Ilic ◽  
Slavica Lazarevic ◽  
Vladana Rajakovic-Ognjanovic ◽  
Ljubinka Rajakovic ◽  
Djordje Janackovic ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Arsenic Removal ◽  
Ph Value ◽  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Deionized Water ◽  
Order Kinetic ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of inorganic arsenic species, As(III) and As(V), from water by sepiolite modified with hydrated iron(III) oxide was investigated at 25 ?C through batch studies. The influence of the initial pH value, the initial As concentrations, the contact time and types of water on the sorption capacity was investigated. Two types of water were used, deionized and groundwater. The maximal sorption capacity for As(III) from deionized water was observed at initial and final pH value 7.0, while the bonding of As(V) was observed to be almost pH independent for pH value in the range from 2.0 to 7.0, and the significant decrease in the sorption capacity was observed at pH values above 7.0. The sorption capacity at initial pH 7.0 was about 10 mg g?1 for As(III) and 4.2 mg g?1 for As(V) in deionized water. The capacity in groundwater was decreased by 40 % for As(III) and by 20 % for As(V). The Langmuir model and pseudo-second order kinetic model revealed good agreement with the experimental results. The results show that Fe(III)-modified sepiolite exhibits significant affinity for arsenic removal and it has a potential for the application in water purification processes.

scholarly journals The Removal of Methylene Blue Dye from Aqueous Solutions Using Activated and Non-Activated Bentonites

2003 ◽  
Vol 21 (5) ◽  
pp. 451-462 ◽  
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Leena Abu-Aitah
Keyword(s):  
Methylene Blue ◽  
Ph Value ◽  
Sodium Dodecyl ◽  
Freundlich Isotherm ◽  
Blue Dye ◽  
Batch Adsorption ◽  
Ionic Surfactant ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Initial Ph

An improvement in the adsorption capacity of naturally available bentonite towards water pollutants such as Methylene Blue dye (MBD) is certainly needed. For this purpose, sodium bentonite was activated by two methods: (1) treatment with sodium dodecyl sulphate (SDS) as an ionic surfactant and (2) thermal treatment in an oven operated at 850°C. Batch adsorption tests were carried out on removing MBD from aqueous solution using the above-mentioned bentonites. It was found that the effectiveness of bentonites towards MBD removal was in the following order: thermal-bentonite > SDS-bentonite > natural bentonite. X-Ray diffraction analysis showed that an increase in the microscopic bentonite platelets on treatment with SDS was the reason behind the higher uptake of MBD. An increase in sorbent concentration or initial pH value of the solutions resulted in a greater removal of MBD from the solution. An increase in temperature led to an increase in MBD uptake by the bentonites studied in this work. The Freundlich isotherm model was employed and found to represent the experimental data well.

High Cr(VI) Adsorption Performance of Coal-Based Activated Carbon in Aqueous Solution

2013 ◽  
Vol 798-799 ◽  
pp. 1123-1127
Author(s):  
Hua Lei Zhou ◽  
Qiong Qiong Zhu ◽  
Dong Hua Huang
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Pore Structure ◽  
Ph Value ◽  
High Surface ◽  
High Surface Area ◽  
Koh Activation ◽  
Transmission Electron ◽  
Mesoporous Adsorbent ◽  
Initial Ph

The activated carbon with high surface area was prepared by KOH activation from anthracite and used as adsorbent for removal of Cr (VI) from aqueous solution. The pore structure and surface properties were characterized by N2 adsorption at 77K, transmission electron microscope (TEM) and Fourier transform infrared spectroscopy ( FTIR). Effect of pH and isotherms at different temperature were investigated. Results show that the prepared carbon is a microporous-and mesoporous-adsorbent with developed pore structure and abundant surface oxygen-containing groups. PH value of the solution plays key function on the adsorption. The chemical adsorption dominates the adsorption process. The activated carbon exhibits much higher Cr adsorption capacity than the commercial activated carbon at initial pH of ~3. The equilibrium adsorption data are fitted by both Freundlich model and Langmuir model well.

scholarly journals Comparison between Different Keratin-composed Biosorbents for the Removal of Heavy Metal Ions from Aqueous Solutions

2002 ◽  
Vol 20 (4) ◽  
pp. 393-416 ◽  
Author(s):  
Fawzi Banat ◽  
Sameer Al-Asheh ◽  
Dheaya‘ Al-Rousan
Keyword(s):  
Aqueous Solutions ◽  
Human Hair ◽  
Metal Ion ◽  
Ph Value ◽  
Freundlich Isotherm ◽  
Operating Conditions ◽  
Ion Uptake ◽  
Chicken Feathers ◽  
Initial Ph ◽  
Metal Ion Uptake

This study examined and compared the ability of chicken feathers, human hair and animal horns, as keratin-composed biosorbents, for the removal of Zn2+ and Cu2+ ions from single metal ion aqueous solutions under different operating conditions. The three biosorbents investigated in this study were all capable of adsorbing Zn2+ and Cu2+ ions from aqueous solutions. The biosorbent showing the highest uptake of Zn2+ and Cu2+ ions was animal horns. Chicken feathers showed a higher Cu2+ ion uptake and a lower Zn2+ ion compared to human hair. Increasing the initial concentration of Zn2+ or Cu2+ ions, or increasing the initial pH value, increased the metal ion uptake. Such uptake decreased when the temperature was raised from 25°C to 50°C for all adsorbent/metal ion combinations except for Zn2+ ion/human hair where the uptake increased with temperature. It was demonstrated that the addition of NaCl salt to the metal ion solution depressed the metal ion uptake. The Freundlich isotherm model was found to be applicable to the adsorption data for Cu2+ and Zn2+ ions.

Screening and Desilication of a Silicate Bacteria

2011 ◽  
Vol 236-238 ◽  
pp. 253-257
Author(s):  
Xian Zhen Zhang ◽  
De Si Sun ◽  
Hai Lin
Keyword(s):  
Particle Size ◽  
Incubation Time ◽  
Ph Value ◽  
Solution Temperature ◽  
Optimum Conditions ◽  
Initial Ph ◽  
Silicate Bacteria ◽  
Bauxite Ore

The strain Jgj-1 was isolated from Gaoan bauxite ore. The relations of desilication of the strain Jgj-1 and the pH of solution, temperature, shaking speed, incubation time, particle size were investigated. The results shows the optimum conditions of bioleaching are as following: at 28°C, initial pH value is 7.2, particle size 0.056mm, 200rpm shaking speed, incubation 5-7 days.

scholarly journals Biogas Production from Combined Irish Potato and Poultry Wastes: Optimization and Kinetic Studies

2018 ◽  
Vol 7 (3.36) ◽  
pp. 170
Author(s):  
Umar M. Ibrahim ◽  
Saeed I. Ahmed ◽  
Babagana Gutti ◽  
Idris M. Muhammad ◽  
Usman D. Hamza ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Kinetic Parameters ◽  
Ph Value ◽  
Biogas Production ◽  
Irish Potato ◽  
Coefficient Of Determination ◽  
Optimum Conditions ◽  
Biogas Yield ◽  
Potato Waste ◽  
Initial Ph

The combination of Irish potato waste (IPW) and poultry waste (PW) can form a synergy resulting into an effective substrate for a better biogas production due to some materials they contain. In this work, optimization and kinetic study of biogas production from anaerobic digestion of IPW and PW was investigated. Response surface methodology (RSM) was applied to optimize conditions such as initial pH, solids concentrations and waste ratios. The anaerobic digestion of the two wastes was carried out in the mesophilic condition and Box-Behnken design (BBD) was used to develop and analyze a predictive model which describes the biogas yield. The results revealed that there is a good fit between the experimental and the predicted biogas yield as revealed by the coefficient of determination (R2) value of 97.93%. Optimization using quadratic RSM predicts biogas yield of 19.75% at the optimal conditions of initial pH value 7.28, solids concentration (w/v) 9.85% and waste ratio (IPW:PW) 45:55%. The reaction was observed to have followed a first order kinetics having R2 and relative squared error (RSE) values of 90.61 and 9.63% respectively. Kinetic parameters, such as rate constant and half-life of the biogas yield were evaluated at optimum conditions to be 0.0392 day-1 and 17.68 days respectively. The optimum conditions and kinetic parameters generated from this research can be used to design real bio-digesters, monitor substrate concentrations, simulate biochemical processes and predict performance of bio-digesters using IPW and PW as substrate.  

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