Experimental Study of Modified Coal Fly Ash Adsorption Properties on Ammonia-Nitrogen in Biogas Slurry

2013 ◽  
Vol 726-731 ◽  
pp. 2687-2690
Author(s):  
Qian Cheng ◽  
Xing Yong Liu ◽  
Min Li

With the development of the biogas construction, a plenty of biogas slurry was generated. It brought destruction to the environment for the biogas slurry was rich in nutrient components, especially ammonia-nitrogen. Its important that biogas slurry should be treated before it returns to the environment. The zeolite is extensively used in ammonia-nitrogen adsorption for its good adsorption effect. In this study, a modified coal fly ash (CFA) which was produced from raw CFA and had similar structure with zeolite was used as the adsorbent to adsorb ammonia-nitrogen in biogas slurry. The optimum adsorption conditions of modified CAF on adsorbing ammonia-nitrogen in biogas slurry were explored. The results showed that the best conditions were: the mass of modified CAF 1.3g, the initial pH value of solution 5~7 and the adsorption time 20 min.

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 707
Author(s):  
Viktoria Keller ◽  
Srećko Stopić ◽  
Buhle Xakalashe ◽  
Yiqian Ma ◽  
Sehliselo Ndlovu ◽  
...  

Acid mine drainage (AMD), red mud (RM) and coal fly ash (CFA) are potential high environmental pollution problems due to their acidity, toxic metals and sulphate contents. Treatment of acidic mine water requires the generation of enough alkalinity to neutralize the excess acidity. Therefore, red mud types from Germany and Greece were chosen for the neutralization of AMD from South Africa, where this problem is notorious. Because of the high alkalinity, German red mud is the most promising precipitation agent achieving the highest pH-values. CFA is less efficient for a neutralization and precipitation process. An increase in temperature increases the adsorption kinetics. The maximum pH-value of 6.0 can be reached by the addition of 100 g German red mud at 20 °C to AMD-water with an initial pH value of 1.9. German red mud removes 99% of the aluminium as aluminium hydroxide at pH 5.0. The rare earth elements (yttrium and cerium) are adsorbed by Greek red mud with an efficiency of 50% and 80% at 60 °C in 5 min, respectively.


2013 ◽  
Vol 690-693 ◽  
pp. 1003-1007
Author(s):  
Chao Jin Wang ◽  
Tai Hang Li ◽  
Ling Lu Tang ◽  
Zhou Zou ◽  
Wen Ji Liu ◽  
...  

The peanut shell was used as the adsorbent of Cr6+ in this paper. A series experiences have been discussed and studied through the following three aspects, which were the adsorption time, modification effect and contact area. The results showed that the peanut shell for the removal rate of Cr6+ presented increasing tendency over time. In condition of 25°C, 1.0g unmodified peanut shell,50mL 30mg·L-1 Cr6+ solution, the initial pH value 1.0 and contact time 300min, the adsorption rate of Cr6+ was only 71%. In the same conditions, the removal rate of modified peanut shell was 75%, compared to the unmodified increasing by 4%. Thus modified treatment for peanut shell has no significant effect on the adsorption effect. And In condition of 25°C, 50mL 30mg·L-1 Cr6+ solution, the initial pH value 1.0 and contact time 270min, the removal rate of 1.0g modified peanut shell was 75%, but the modified peanut shell powders removal rate was 99%, representing an increase of 25% before crushing, thus to increase the contact area can improve the adsorption effect.


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1461
Author(s):  
Quanguo Zhang ◽  
Zexian Liu ◽  
Francesco Petracchini ◽  
Chaoyang Lu ◽  
Yameng Li ◽  
...  

The insecticidal ingredient in a biogas solution being fully utilized by cation exchange resin to produce slow-release insecticide is of great social value. In this work, the feasibility of ammonia nitrogen in a biogas slurry loaded on resin as a slow-release insecticide was evaluated by studying the effect of adsorption and the slow release of ammonia nitrogen by resin. The effects of the ammonia nitrogen concentration, resin dosage, adsorption time and pH value on the ammonia nitrogen adsorption by the resin were studied. The results showed that the ion exchange resin had a good adsorption effect on the ammonia nitrogen. With the increase of the resin dosage, time and ammonia nitrogen concentration, the adsorption capacity increased at first and then stabilized. The ammonia nitrogen adsorption capacity reached its maximum value (1.13 mg) when the pH value was 7. The adsorption process can be fitted well by the Langmuir isothermal adsorption equation and quasi-second-order kinetic model. Additionally, the release rate of the ammonia nitrogen increased with the increasing sodium chloride concentration. The adsorption capacity of ammonia nitrogen by the D113 (resin type) resin decreased by 15.8% compared with the ammonium chloride solution. The report shows that the ion exchange resin has a good adsorption effect on ammonia nitrogen, which is of guiding significance for expanding the raw materials for slow-release insecticides, improving the utilization rate of biogas slurry and cleaner production of slow-release insecticides from biogas slurry. Additionally, all variables showed statistical differences (p < 0.05).


1996 ◽  
Vol 13 (6) ◽  
pp. 527-536 ◽  
Author(s):  
L.J. Alemany ◽  
M.C. Jiménez ◽  
M.A. Larrubia ◽  
F. Delgado ◽  
J.M. Blasco

The present work examines the possible use of fly ash, a byproduct of coal power stations, as a means of removing phenol from water, or equivalently, of restricting its movement in solid wastes or soil. Equilibrium experiments were performed to evaluate the removal efficiency of fly ash. The adsorption experiments were undertaken using fly ash treated at three different pH levels and with three different temperatures. The results indicate that although phenol can be removed from water, this depends markedly on the temperature and pH value of the treatment solution employed.


2018 ◽  
Vol 77 (5) ◽  
pp. 1363-1371 ◽  
Author(s):  
Yong Fu ◽  
Yue Huang ◽  
Jianshe Hu ◽  
Zhengjie Zhang

Abstract A green functional adsorbent (CAD) was prepared by Schiff base reaction of chitosan and amino-modified diatomite. The morphology, structure and adsorption properties of the CAD were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and Brunauer Emmett Teller measurements. The effect of pH value, contact time and temperature on the adsorption of Hg(II) ions for the CAD is discussed in detail. The experimental results showed that the CAD had a large specific surface area and multifunctional groups such as amino, hydroxyl and Schiff base. The optimum adsorption effect was obtained when the pH value, temperature and contact time were 4, 25 °C and 120 min, respectively, and the corresponding maximum adsorption capacity of Hg(II) ions reached 102 mg/g. Moreover, the adsorption behavior of Hg(II) ions for the CAD followed the pseudo-second-order kinetic model and Langmuir model. The negative ΔG0 and ΔH0 suggested that the adsorption was a spontaneous exothermic process.


2014 ◽  
Vol 955-959 ◽  
pp. 360-365
Author(s):  
Min Han ◽  
Cheng Hong Feng ◽  
Shun Li Wang ◽  
Ye Quan Fu ◽  
Li Qing An ◽  
...  

To explore purification approach of anaerobic-digested-slurry from cattle dung, this study translated a technology in inorganic coagulation. Under the same condition, a coagulation experiment was carried out by three kinds inorganic coagulants such as polyaluminium chloride (PAC), aluminum sulfate and ferric chloride, respectively, then measured indicators of pH value, BOD5 value, CODcr value, ammonia nitrogen value, turbidity value. Results showed that there was a varying degree of purification effect, and the removal rate of the above indicators increased as the coagulant dosage increasing, the ferric chloride with the dosage of 960mg/L was the best one in purifying effect among the three coagulants. It is feasible that coagulation technology was used to pretreatment biogas slurry from cattle dung, and most of the indicators reached Chinese national standard basically (GB 18596-2001).


2011 ◽  
Vol 356-360 ◽  
pp. 493-497 ◽  
Author(s):  
Zong Ning Li ◽  
Zong Qiang Zhu ◽  
Mei Na Liang ◽  
Hong Dong Qin ◽  
Yi Nian Zhu

The influences of adsorption temperature, adsorption time, dosing quantity, adsorption environment pH value, initial concentration and bamboo charcoal type on adsorption of bamboo charcoal adsorb ammonia nitrogen in wastewater are studied. The result shows that the maximum adsorption values are 1.1715 mg/g and 0.9115 mg/g respectively at 25°C and 40°C. Bamboo charcoal can easily absorb ammonia nitrogen at low temperature condition. 180 min is a suitable adsorption time. Increasing bamboo charcoal dosing quantity is helpful to improve efficiencies of ammonia nitrogen removal in wastewater, but the adsorption capacity is declining as bamboo charcoal dosing quantity increasing. Solution pH value has a great impact on the adsorbed amount, the adsorbed effect in alkaline solution is much better than in acid one’s. The adsorption ability of the moderate temperature bamboo charcoal is higher than the high temperature one’s.


Author(s):  
Mengyuan Zou ◽  
Hongmin Dong ◽  
Zhiping Zhu ◽  
Yuanhang Zhan

Ammonia stripping is a pretreatment method for piggery biogas slurry, and the effectiveness of the method is affected by many factors. Based on the results of single-factor experiments, response surface methodology is adopted to establish a quadratic polynomial mathematical model relating stripping time, pH value and gas flow rate to the average removal rate of ammonia nitrogen to explore the interactions among various influencing factors, obtain optimized combined parameters for ammonia stripping, and carry out experimental verification of the parameters. The results show that when hollow polyhedral packing is adopted under operating conditions including a stripping time of 90 min, pH value of 11, gas flow rate of 28 m3/h, gas–liquid ratio of 2000 and temperature of 30 °C, the average removal rate of ammonia nitrogen in biogas slurry can reach approximately 73%. The experimental value is only 4.2% different from the predicted value, which indicates that analysis on the interaction among factors influencing ammonia stripping of biogas slurry and parameter optimization of the regression model are accurate and effective.


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