scholarly journals Elimination of Microcystis aeruginosa Kütz. by modified walnut and peanut shells with phosphoric acid

2018 ◽  
Vol 47 (4) ◽  
pp. 823-829
Author(s):  
Hongqiang Wang ◽  
Lieyu Zhang ◽  
Hong Liu

The phosphoric acid modified walnut and peanut shell were prepared and applied for the removal of the blue-green alga (Microcystis aeruginosa Kütz.). Orthogonal experiment was used to optimize the modified condition. For the efficient removal, 0.05 g of the modified walnut and peanut shell was added into 50 ml of algal culture and kept standing for 4 hrs. This condition was found best and under which the removal rate of algae can be reached > 90%. At the same time, a comparison between unmodified walnut and peanut shell and modified walnut and peanut shell on the removal of M. aeruginosa cells showed that, unmodified walnut and peanut shell have a removal rate of 31.51 and 29.90%, respectively. On the other hand, the modified walnut and peanut shell showed a removal rate of 96.55 and 93.75%, respectively. Walnut and peanut shells modified with phosphoric acid enhanced the removal efficiency of M. aeruginosa cells. So, the modified walnut and peanut shell were considered as a potential algaecide with high efficiency of obnoxious algae removal from the environment safely.

2011 ◽  
Vol 71-78 ◽  
pp. 3029-3032 ◽  
Author(s):  
Xin Zhao ◽  
Chao Yu Hu ◽  
Xu Yan

In order to investigate the adsorption of hexavalent chrome in wastewater by peanut shell, the orthogonal test was designed to find the best adsorption conditions such as pH value, temperature, adsorption time and adsorbent dosage etc. The results show that the peanut shell is a kind of economic and efficient absorbent; hexavalent chrome removal rate can reach more than 85%, when the hexavalent chrome wastewater concentration is 30mg/L, dosing 1g peanut shells into 50mg wastewater, adjusting pH value to 2.0, adsorbing 300min at room temperature.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Runlan Yu ◽  
Meilian Man ◽  
Zhaojing Yu ◽  
Xueling Wu ◽  
Li Shen ◽  
...  

AbstractIn polluted groundwater, surface water, and industrial sites, chromium is found as one of the most common heavy metals, and one of the 20 main pollutants in China, which poses a great threat to the ecological environment and human health. Combining biological and chemical materials to treat groundwater contaminated by heavy metals is a promising restoration technology. In this research, Klebsiella variicola H12 (abbreviated as K. variicola) was found to have Cr(VI) reduction ability. A high-efficiency Klebsiella variicola H12-carboxymethyl cellulose (abbreviated as CMC)-FeS@biochar system was established for Cr(VI) removal from aqueous solution. The Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM–EDS), X-ray photoelectron spectroscopy (XPS) results indicated that CMC-FeS was successfully loaded onto the surface of biochar, and K. variicola H12 grew well in the presence of CMC-FeS@biochar with microbial biomass up to 4.8 × 108 cells mL−1. Cr(VI) removal rate of CMC-FeS@biochar system, K. variicola H12 system and K. variicola H12 + CMC-FeS@biochar system were 61.8%, 82.2% and 96.6% respectively. This study demonstrated K. variicola H12-CMC-FeS@biochar system have potential value for efficient removal of Cr(VI) from Cr(VI)-polluted groundwater.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1732
Author(s):  
Yuanyuan Yu ◽  
Yongjun Sun ◽  
Jun Zhou ◽  
Aowen Chen ◽  
Kinjal J. Shah

In this study, a high-efficiency magnetic heavy metal flocculant MF@AA was prepared based on carboxymethyl chitosan and magnetic Fe3O4. It was characterized by SEM, FTIR, XPS, XRD and VSM, and the Cu(II) removal rate was used as the evaluation basis for the preparation process. The effects of AMPS content, total monomer concentration, photoinitiator concentration and reaction time on the performance of MF@AA flocculation to remove Cu(II) were studied. The characterization results show that MF@AA has been successfully prepared and exhibits good magnetic induction characteristics. The synthesis results show that under the conditions of 10% AMPS content, 35% total monomer concentration, 0.04% photoinitiator concentration, and 1.5 h reaction time, the best yield of MF@AA is 77.69%. The best removal rate is 87.65%. In addition, the response surface optimization of the synthesis process of MF@AA was performed. The optimal synthesis ratio was finally determined as iron content 6.5%, CMFS: 29.5%, AM: 53.9%, AMPS: 10.1%. High-efficiency magnetic heavy metal flocculant MF@AA shows excellent flocculation performance in removing Cu(II). This research provides guidance and ideas for the development of efficient and low-cost flocculation technology to remove Cu(II) in wastewater.


Proceedings ◽  
2018 ◽  
Vol 2 (10) ◽  
pp. 567 ◽  
Author(s):  
Željka Fiket ◽  
Ana Galović ◽  
Gordana Medunić ◽  
Martina Furdek Turk ◽  
Maja Ivanić ◽  
...  

Rare earth elements, i.e., lanthanides, are important components of many recently developed technology applications. However, their increasing use in the industrial sector, medicine, and agriculture over the last few decades has provided them with the title of “new pollutants”. Different methods are now applied for the removal of various pollutants from wastewaters, whereby the emphasis is placed on adsorption due to its simplicity, high efficiency, and low cost. In the present study, geopolymers prepared from coal ash were examined regarding their capacity for the adsorption of lanthanides from model solutions. The obtained results indicate the efficient removal of lanthanides by prepared geopolymers, depicting them as effective adsorbents for this group of elements.


2015 ◽  
Vol 57 (43) ◽  
pp. 20483-20493 ◽  
Author(s):  
Jianchao Hao ◽  
Bin Lian ◽  
Ruanbao Zhou ◽  
Huifen Liu ◽  
Lijun Shi ◽  
...  

2017 ◽  
Author(s):  
K. L. Tan ◽  
S. H. Yeo

Non-contact ultrasonic abrasive machining (NUAM) is a variant of ultrasonic machining (USM). In NUAM, material is removed predominantly by cavitation erosion in abrasive slurry. Due to a significantly lower material removal rate than traditional USM, NUAM is investigated for its applicability on surface modification and finishing in this study. Experiments were conducted on SUS304 steel samples machined by wire electrical discharged machining (WEDM). Due to the thermal spark phenomenon during WEDM, a thermal recast layer, of thickness approximately 15 μm, is often left over on the specimen’s surface after the process. The undesired thermal recast layer contributes to the poor surface integrity of specimens. A NUAM system was configured using a 40 kHz ultrasonic system. Ultrasonic vibration amplitude of 70 μm at the horn tip was used to generate cavitation bubbles in the abrasive slurry. NUAM was found to be effective in removing the unstable thermal recast layers by means of cavitation erosion. As a result, the average surface roughness, Ra, of the specimens improved from approximately 2.5 μm to ∼1.7 μm after 20 minutes of processing time. Furthermore, the addition of abrasive particles was observed to aid in more efficient removal of thermal recast layers than a pure cavitation condition.


2018 ◽  
Vol 10 (9) ◽  
pp. 3254 ◽  
Author(s):  
Miguel-Angel Perea-Moreno ◽  
Francisco Manzano-Agugliaro ◽  
Quetzalcoatl Hernandez-Escobedo ◽  
Alberto-Jesus Perea-Moreno

The peanut (Arachys hypogaea) is a plant of the Fabaceae family (legumes), as are chickpeas, lentils, beans, and peas. It is originally from South America and is used mainly for culinary purposes, in confectionery products, or as a nut as well as for the production of biscuits, breads, sweets, cereals, and salads. Also, due to its high percentage of fat, peanuts are used for industrialized products such as oils, flours, inks, creams, lipsticks, etc. According to the Food and Agriculture Organization (FAO) statistical yearbook in 2016, the production of peanuts was 43,982,066 t, produced in 27,660,802 hectares. Peanuts are grown mainly in Asia, with a global production rate of 65.3%, followed by Africa with 26.2%, the Americas with 8.4%, and Oceania with 0.1%. The peanut industry is one of the main generators of agroindustrial waste (shells). This residual biomass (25–30% of the total weight) has a high energy content that is worth exploring. The main objectives of this study are, firstly, to evaluate the energy parameters of peanut shells as a possible solid biofuel applied as an energy source in residential and industrial heating installations. Secondly, different models are analysed to estimate the higher heating value (HHV) for biomass proposed by different scientists and to determine which most accurately fits the determination of this value for peanut shells. Thirdly, we evaluate the reduction in global CO2 emissions that would result from the use of peanut shells as biofuel. The obtained HHV of peanut shells (18.547 MJ/kg) is higher than other biomass sources evaluated, such as olive stones (17.884 MJ/kg) or almond shells (18.200 MJ/kg), and similar to other sources of biomass used at present for home and industrial heating applications. Different prediction models of the HHV value proposed by scientists for different types of biomass have been analysed and the one that best fits the calculation for the peanut shell has been determined. The CO2 reduction that would result from the use of peanut shells as an energy source has been evaluated in all production countries, obtaining values above 0.5 ‰ of their total emissions.


2021 ◽  
Vol 17 ◽  
pp. 2729-2764
Author(s):  
Alemayehu Gashaw Woldegiorgis ◽  
Xufeng Lin

In recent years, the synthesis of axially chiral compounds has received considerable attention due to their extensive application as biologically active compounds in medicinal chemistry and as chiral ligands in asymmetric catalysis. Chiral phosphoric acids are recognized as efficient organocatalysts for a variety of enantioselective transformations. In this review, we summarize the recent development of chiral phosphoric acid-catalyzed synthesis of a wide range of axially chiral biaryls, heterobiaryls, vinylarenes, N-arylamines, spiranes, and allenes with high efficiency and excellent stereoselectivity.


2015 ◽  
Vol 8 (3) ◽  
pp. 941-955 ◽  
Author(s):  
Jia Ding ◽  
Huanlei Wang ◽  
Zhi Li ◽  
Kai Cui ◽  
Dimitre Karpuzov ◽  
...  

Hybrid sodium ion capacitor with the active materials in both electrodes derived from peanut shells bridges the critical battery–supercapacitor divide.


2021 ◽  
Vol 45 (37) ◽  
pp. 17483-17492
Author(s):  
Xuechun Wei ◽  
Hongxiang Zhu ◽  
Jianhua Xiong ◽  
Wenyu Huang ◽  
Ji Shi ◽  
...  

Fluorine-doped TiO2 was successfully synthesised and applied as algaecide. Studies on algae removal efficiencies and mechanisms illustrated that F-TiO2 was suitable for algae elimination in natural water bodies.


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