scholarly journals Research technology of cultivation of spirulina algae with the use of CO2 hidden from the smoke of rice husk boiler

2021 ◽  
pp. 22-26
Author(s):  
Trinh Van Dung ◽  
Phan Quoc Thinh ◽  
Nguyen Quoc Dat ◽  
Pham Van Hung
Keyword(s):  
Rice Husk ◽  
Ph Value ◽  
Control Sample ◽  
Biomass Concentration ◽  
Growth Yield ◽  
Algae Biomass ◽  
Co2 Gas ◽  
Research Technology ◽  
Algae Cultivation ◽  
Ph Increase

This paper presents an investigation of Spirulina algae cultivation by the CO2 gas emitted from the combustion of rice husk. The gas emitted from the rice husk combustion containing CO2 but no toxic gas of SOx. The CO2 molecules are absorbed into the micro-algae cultivation medium and then converted into the HCO3 by the assimilation of Spirulina. At the same time, the pH values are controlled to be from 8.5 to 9.5, which is suitable for Spirulina algae. At the first seven days of cultivation in Zarrouk medium the values of Spirulina algae biomass and pH increase from 0.05 g/l and 8.5 to 1.0 g/l and 10.2, respectively. On the 8th day, when the amount of 7,6 % CO2  v/v under 35–40 ºC and 1 atm is introduced into the above medium, the decrease of pH from 10.2 to 8.6 is observed. This pH value, which is maintained over the following days, is optimal for the growth yield of the Spirulina. As a result, the biomass concentration increases from 1.0 to 1.4 g/l. The obtained results are compared with those of the control sample from Zarrouk medium without gas introduction. For the latter case, the biomass reaches the maximum and then decreases. On the basis of the obtained results, the cultivation of Spirulina algae by using the CO2 molecules emitted from the combustion of rice husk can be applied practically.

scholarly journals Sonochemically synthetized ZnO-Graphene nanohybrids and its characterization

2020 ◽  
Vol 59 (1) ◽  
pp. 176-187 ◽  
Author(s):  
Cornel Cobianu ◽  
Niculae Dumbravescu ◽  
Bogdan-Catalin Serban ◽  
Octavian Buiu ◽  
Cosmin Romanitan ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Ph Value ◽  
Raman Band ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Carbon Incorporation ◽  
Additional Amount ◽  
Ph Increase ◽  
Compositional Properties ◽  
Crystalline Symmetry

AbstractThe paper presents the morphological, structural and compositional properties of the sonochemically prepared ZnO-1.4wt% Graphene (Z-G) nanocomposites as a function of pH value of suspension varying from 8.5 to 14 and thermal annealing at 450°C in nitrogen or air ambient. The SEM analysis of the Z-G hybrids dried at 150°C in air has shown a nano-flower like nanostructure for a pH value of 14. The XRD analysis of dried Z-G hybrids revealed a crystallite size increase from 3.5 nm to 18.4 nm with pH increase, and this result was explained in terms of colloids zeta potential evolution with pH value. The Raman and EDS spectroscopy have shown a split of the G band (1575 cm−1) of graphene into two bands (1575 cm−1 and 1605 cm−1), an increased height of D (1323 cm−1) band, and an additional amount of carbon due to CO2 absorption from the air, respectively. The carbon incorporation increased with the decrease of pH, and was associated with a hydrozincite phase, Zn5(CO3)2(OH)6. The formation of dried Z-G nanocomposite was clearly demonstrated only at a pH value equal to 14, where two ZnO Raman active bands at 314.9 cm−1 and 428.2 cm−1 appeared. This result may indicate the sensitivity of the Raman spectroscopy to the nanoflower-like nanostructure of dried Z-G hybrids prepared at pH=14. The thermal treatment of Z-G hybrids in N2at 450°C has increased the number of ZnO Raman bands as a function of pH value, it has decreased the amount of additional carbon by conversion of hydrozincite to ZnO and preserved the graphene profile. The thermal treatment in air at 450°C has increased the crystalline symmetry and stoichiometry of the ZnO as revealed by high and narrow Raman band from 99 cm−1 specific to Zn optical phonons, but it has severely affected the graphene profile in the Z-G hybrid, due to combustion of graphene in oxygen from the ambient.

Determination of the Maintenance Requirements of Activated Sludge

1993 ◽  
Vol 28 (7) ◽  
pp. 139-142 ◽  
Author(s):  
J. Chang ◽  
P. Chudoba ◽  
B. Capdeville
Keyword(s):  
Wastewater Treatment ◽  
Process Development ◽  
Biomass Concentration ◽  
Growth Yield ◽  
Kinetic Studies ◽  
Initial Biomass Concentration ◽  
Aerobic Wastewater Treatment ◽  
Initial Substrate ◽  
Maintenance Requirements ◽  
The Cost

Maintenance energy plays an important role both in basic kinetic studies and in process development. Numerous studies have been devoted to the maintenance concept in various microbial fields but very few in biological wastewater treatment. Using a fermenter coupled to a mass spectrometer, we investigated the influence of the ratio So/Xo (ratio between initial substrate concentration and initial biomass concentration) on the observed sludge growth yield of an oxic-settling anaerobic (OSA) system. By measuring the substrate removed, the oxygen consumed and the carbon dioxide produced, we were able to estimate the substrate fraction used for maintenance purposes. The results indicate that at a high So/Xo ratio, a greater proportion of the substrate is devoted to maintenance thus significantly decreasing the observed growth yield. These findings are of particular importance in view of the cost associated with the disposal of excess sludge in aerobic wastewater treatment processes.

Identification of yeasts in different rubber leaf (Hevea brasiliensis) clones and their effects on the physical properties of fermented glutinous rice tapai

Food Research ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 29-37
Author(s):  
Z. Mohd Zin ◽  
N.I. Azman ◽  
S.B. Abd Razak ◽  
K. Ibrahim ◽  
N.D. Rusli ◽  
...  
Keyword(s):  
Physical Properties ◽  
Ph Value ◽  
Control Sample ◽  
Candida Guilliermondii ◽  
Solid Content ◽  
Soluble Solids ◽  
Soluble Solid Content ◽  
Rhodotorula Mucilaginosa ◽  
Glutinous Rice ◽  
Before And After

Tapai is one of the most popular traditional desserts in Malaysia and other Asian countries. Traditionally, tapai is wrapped in a rubber leaf to enhance the smell and increase its palatability. The study focused on identifying the yeasts present before and after the production of glutinous rice tapai wrapped in different rubber leaves clones, namely RRIM 2025, RRIM 2002, PB 260 and PB 350. The identification of the yeast was carried out using API 20C AUX test strips for all rubber leaves clones, glutinous rice tapai wrapped in RRIM 2025, RRIM 2002, PB 260, PB 350 and in a container (control). The results showed that Crytococcus laurentii, Rhodotorula mucilaginosa 2, Candida famata, Rhodotorula minuta were present in rubber leaf clones. While the yeasts that had been identified in tapai wrapped in rubber leaf were Candida guilliermondii, Rhodotorula mucilaginosa 2, Candida parapsilosis and Trichosporon mucoides and only C. guilliermondii was found in the container. The physical properties of the tapai that are wrapped in rubber leaves have a difference in texture, pH value and total soluble solids content compared to the control sample. The tapai sample wrapped in RRIM 2025 and RRIM 2002 had a high total soluble solid content of 45.8±0.14% and 45.78±0.16% °Bx, respectively. Meanwhile, the control sample has the highest pH value and the hardest rice kernels, which were 4.71±0.05 and 218.19±25.39 N, respectively. The results showed that the different yeasts present in the rubber leaf may cause changes in the physical properties of glutinous rice tapai.

scholarly journals Study of Chlorella vulgaris sedimentation process

2018 ◽  
Vol 240 ◽  
pp. 05023 ◽  
Author(s):  
Agnieszka Patyna ◽  
Małgorzata Płaczek ◽  
Stanisław Witczak
Keyword(s):  
Chlorella Vulgaris ◽  
Dry Mass ◽  
Separation Process ◽  
Cultivation Condition ◽  
Microalgal Biomass ◽  
Algae Biomass ◽  
Algae Cultivation ◽  
Sedimentation Process ◽  
Microalgae Harvesting

The paper reports the results of Chlorella vulgaris sedimentation process including description of cultivation condition of microalgal biomass. The process of algae cultivation was carried out in photobioreactor comprising systems of carbon dioxide supply, mixing and artificial LED illumination. The growth of microalgae was determined alternatively in three ways by measuring the amount of dry mass over time, counting the cells and measurement of optical density by use of a spectrophotometer. Algae biomass with different concentration was subjected to the separation process by gravity. This led to the determination of the characteristic of sedimentation process for different concentrations and cell sizes. The experimental results indicate that sedimentation process offers a tool with a potential application for microalgae harvesting.

New techniques for ion-selective measurements of ionized calcium in serum after pH adjustment of aerobically handled sera.

1976 ◽  
Vol 22 (4) ◽  
pp. 461-467 ◽  
Author(s):  
H D Schwartz
Keyword(s):  
Ph Value ◽  
Blood Gas Analysis ◽  
Electron System ◽  
Selectivity Coefficient ◽  
Gas Analysis ◽  
Ionized Calcium ◽  
Bicarbonate Concentration ◽  
Co2 Gas ◽  
The Relationship ◽  
Acid Base Disturbance

Abstract I report further experience in measuring ionized calcium (Ca2+) with the AMT Electron System and its serum standards and solid-state, dip, calcium-selective electrodes. With this system, serum pH can be adjusted with CO2 gas and Ca2+ and pH simultaneously measured; when 5.2% CO2 (40 mm pco2) is used for sample equilibration, the standard bicarbonate concentration is also provided. I measured serum Ca2+ as a function of pH between pH 7.0 and 9.0 and found the relationship to be reproducible, with no evidence of irreversible complexing of Ca2+. When the pH of aerobically exposed, mailed sera was restored to the original values, their values for Ca2+ were the same as for the fresh sera. Measurement of Ca2+ in routinely (aerobically) handled sera after pH restoration with CO2 gas was therefore validated, both samples from within an institution and mailed specimens. Standardization to pH 7.40 is recommended for routine measurements, is generally more accurate than use of heparin or quasianaerobic techniques, and is a practical approach. In patients with possible uncompensated acid-base disturbance (which may be indicated by an abnormal standard bicarbonate concentration if not suspected clinically), patient pH should be measured independently as part of the usual strict, anaerobic blood-gas-analysis procedures. Abnormal patient pH must be considered in the interpretation of Ca2+ results determined at pH 7.40 which are borderline or slightly abnormal; most accurately, Ca2+ may be measured in the separated sera at the previously determined patient pH value. Studies of aqueous solutions with the currently used Ca2+ electrodes showed a selectivity coefficient (the constant which relates the activity of an interfering ion to the activity of calcium that would contribute the same emf) KNa=0.0031 +/- 0.0003 (SE) and KMg=0.046 +/- 0.004 (SE). At physiological concentrations of Ca2+, physiologically encountered variation in Na+ is of no significance in resulting Ca2+, but extreme variation in Mg2+ may cause an error of approximately 1%.

scholarly journals Hydrochloric Acid Pretreatment of Different Types of Rice Husk Ash Influence on the Properties of Cement Paste

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1524 ◽  
Author(s):  
Jing Liu ◽  
Chunyan Xie ◽  
Chao Fu ◽  
Xiuli Wei ◽  
Dake Wu
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Cement Paste ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Control Sample ◽  
Control Group ◽  
Rice Husks ◽  
Acid Pretreatment ◽  
Blank Control Group

When properly processed, rice husk ash (RHA) comprises a large amount of SiO2, which exhibits a high pozzolanic activity and acts as a good building filler. In this paper, the effects of rice husk ash content, acid pretreatment, and production regions on the compressive and flexural properties and water absorption of a cement paste were studied. The experimental results showed that the compressive strength of the rice husk ash was the highest with a 10% content level, which was about 16.22% higher than that of the control sample. The rice husk after acid pretreatment displayed a higher strength than that of the sample without the acid treatment, and the rice husk from the Inner Mongolia region indicated a higher strength than that from the Guangdong province. However, the flexural strength of each group was not significantly different from that of the blank control group. The trend observed for the water absorption was similar to that of the compressive strength. The variation in the RHA proportions had the greatest influence on the properties of the paste specimens, followed by the acid pretreatments of the rice husks. The production regions of the rice husks indicated the least influence.

Adsorption Mechanism of Copper(II) Ions on Expansion-Treated Rice Husk

2011 ◽  
Vol 695 ◽  
pp. 13-16
Author(s):  
Xuan Liang ◽  
Xue Gang Luo ◽  
Xiao Yan Lin
Keyword(s):  
Removal Efficiency ◽  
Rice Husk ◽  
Photoelectron Spectroscopy ◽  
Adsorption Mechanism ◽  
Ph Value ◽  
Water Solution ◽  
Whole Process ◽  
Monolayer Adsorption ◽  
Strong Adsorption ◽  
Bulk Structures

Expansion-treated rice husk (ERH) had been used as adsorbent for removing copper(II) ions, and showed strong adsorption ability and removal efficiency for copper(II) ions. In this paper, the surface and bulk structures of ERH adsorbent were investigated by X-ray photoelectron spectroscopy (XPS) and scanning electronic microscopy (SEM), ERH was treated by water solution with different pH value, and the adsorption performance of ERH for copper(II) ions was investigated through adsorption static experiments in order to study the adsorption mechanism. The result showed that ERH treated by alkaline solution had high removal efficiency for copper(II) ions, the reason ascribed to the large surface area of ERH. ERH had competitive adsorption for H+ and Cu2+, and a monolayer adsorption process played an important role in the whole process.

scholarly journals Preparation and characterization of activated carbon & amorphous silica from rice husk

2015 ◽  
Vol 50 (4) ◽  
pp. 263-270 ◽  
Author(s):  
MT Rhaman ◽  
MA Haque ◽  
MA Rouf ◽  
MAB Siddique ◽  
MS Islam
Keyword(s):  
Activated Carbon ◽  
Rice Husk ◽  
Amorphous Silica ◽  
Ph Value ◽  
Koh Activation ◽  
Silica Sample ◽  
Alkali Extraction ◽  
Sem Image ◽  
Value Measurement ◽  
Mb Adsorption

Activated carbon (AC) was prepared by the conventional carbonization and KOH activation and amorphous silica was extracted by alkali extraction followed by acid precipitation from rice husk on a laboratory scale. The performance of the produced activated carbon and amorphous silica were examined using I2 value measurement, methylene blue (MB) adsorption test, pH measurement, FTIR and SEM-EDX analysis. The optimum temperature for production of AC was obtained at 700 0C. The AC by alkali extraction method was show higher activity than KOH activation. The maximum I2 value, MB adsorption value & pH value shows at 700 0C followed by alkali extraction with 15% NaOH, which were 510.82 mg/g, 61.1 mg/g and 7.32 respectively. The FTIR analysis shows presence of Si-O-Si bond with a strong peak at 1078.28 cm-1. The SEM image of silica sample shows that the most of organic component is burnt out during combustion.Bangladesh J. Sci. Ind. Res. 50(4), 263-270, 2015

scholarly journals Ion exchange Behavior of Polyaniline and Polyaniline/Silica Composite

2020 ◽  
Vol 17 (1) ◽  
pp. 59
Author(s):  
Amirah Amalina Ahmad Tarmizi ◽  
Muhammad Adam 'Azmi
Keyword(s):  
Ion Exchange ◽  
Metal Ions ◽  
Rice Husk ◽  
Inductively Coupled Plasma ◽  
Contact Time ◽  
Ph Value ◽  
Potassium Dichromate ◽  
Optical Emission ◽  
Silica Composite ◽  
Exchange Behaviour

This study was conducted to compare the ion exchange behaviour of polyaniline (PANI) and polyaniline/silica (PANI/silica) composite. Rice husk silica (SiRH) was obtained from the combustion of rice husk ash followed by acid digestion method using sulfuric acid. Next, pristine PANI was synthesized via in situ oxidative polymerisation method using aniline and potassium dichromate in the acidic medium. Composite of PANI/SiRH was prepared with a similar method with the addition of SiRH in the process. Characterisations were done by employing X-Ray diffractometry and Fourier transform infrared spectroscopy. Polyaniline and PANI/SiRH composite were mixed with a solution containing Na+, Mg2+, and K+. The concentrations of metal ions before and after contact with PANI and PANI/SiRH were measured using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The effect of SiRH composition, contact time and pH on the ion exchange behaviour of PANI and PANI/SiRH composite was investigated. Results revealed that higher SiRH content in PANI/SiRH shows better ion-exchange properties with the optimum contact time of 30 minutes. The pH value of the metal ions decreased throughout the experiment.

scholarly journals SURFACE MODIFICATION OF ACTIVATED CARBON FROM RICE HUSK FOR ENHANCING THE NICKEL(Ni2+) AND CADMIUM (Cd2+) ADSORPTION CAPACITY

2018 ◽  
Vol 54 (4B) ◽  
pp. 19
Author(s):  
Hoa Thai Ma
Keyword(s):  
Surface Modification ◽  
Activated Carbon ◽  
Reaction Time ◽  
Optimal Condition ◽  
Adsorption Capacity ◽  
Rice Husk ◽  
High Surface ◽  
Control Sample ◽  
Equilibrium Concentration ◽  
Modification Process

Activated carbon (AC) has been proven to be an effective adsorbent for the removal of a variety of pollutants. AC is extensively used for adsorption because its high surface area is well-developed internal micro porosity. The objective of this study is to determine the optimal condition of the surface modification process of activated carbon from rice husk (ACRH) using HNO3. That increase the functional group, and improve affinity towards certain contaminants of ACRH for increasing the adsorption capacity of Ni2+ and Cd2+. Two factors were taken into account as: the concentration of HNO3 (1, 3, and 5 M), reaction time (1, 2, 3, 4 and 5 hours). The results showed that the optimal condition of the surface modification process was derived at the equilibrium concentration of HNO3 = 3 M and the equilibrium reaction time = 4 hour. Interestingly, in comparison with the control sample (ACRH not modified), the adsorption capacity of Ni2+ and Cd2+ increased from 10.0 to 17.2 mg/g and 10.4 to 29.6 mg/g, respectively. This adsorption capacity of modified ACRH shows the increase significantly.

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