The Treatment of Acid Copper-Containing Wastewater by Eggshell-Flyash System

2011 ◽  
Vol 183-185 ◽  
pp. 967-970
Author(s):  
Tao Liu

Removal efficiency of heavy metal Cu from acid wastewater using egg shell as adsorbent was investigated. The influence of calcination temperature and dosage of egg shell, as well as pH value on the removal efficiency were discussed to obtain the optimum removal condition. The results show that the removal rate of lead would achieve the best result of 99.56% when we use the egg shells calcined at 400°C,2h, and the content of egg shells is 30g/L, pH=3.0.Using eggshells to treat acid chrome-containing wastewater is simple and easy to be operated, which has application prospects for the process and good treatment effect.

2011 ◽  
Vol 255-260 ◽  
pp. 2797-2801
Author(s):  
Chen Yao ◽  
Chun Juan Gan ◽  
Jian Zhou

Effect of environment factors such as initial pH value, dissolved oxygen (DO) and temperature on phosphorus removal efficiency of phosphate reduction system was discussed in treating pickled mustard tube wastewater. Results indicate that environment factors have significant influence on dephosphorization efficiency. And, the impact of DO on phosphate reduction is mainly by affecting the distribution of micro-environment inner biofilm, manifest as phosphate removal rate decreased with a fall in DO concentration, while overhigh DO can lead to detachment of biofilm, thus causing the increase of effluent COD concentration, and so DO need to be controlled in the range of 6 mg/L. Moreover, a higher temperature is more beneficial to phosphorus removal by PRB. Unfortunately, exorbitant temperature can result in mass rearing of Leuconostoc characterized with poor flocculability in reactor, and that cause turbidity in effluent appeared as a rise in COD of effluent. Hence, the optimal temperature is found to be about 30°C.


2014 ◽  
Vol 609-610 ◽  
pp. 311-316
Author(s):  
Xiao Cai Yu ◽  
Dong Dong Hu ◽  
Jin Fang Chen ◽  
Xiao Jie Jin ◽  
Xu Zheng

ZnO and Ag-droped ZnO photocatalysts with different Ag loadings (0.5, 1.0, 1.5, 2.0at%) and different calcination temperature (300, 400, 500, 600, 700°C) were synthesized by a sonochemical method. The morphology and crystal pattern of some prepared catalysts were characterized by XRD and SEM techniques which demonstrated that the prepared catalysts were of hexagonal wurtzite structure. Ag loadings, calcination temperature and other factors, dosage of photocatalyst, reaction time and pH value of seawater, were also taken into consideration in the procedure of photocatalytic degradation reaction under UV light. An orthogonal experiment was carried out to investigate the best combination of factors which can reach the best diesel pollution removal rate and the influence order of factors. Reaction time and dosage of catalyst were the most influential factors in this experiment, and the factor of calcination temperature was the weakest influential factor. The removal rate of diesel can up to 78% when the experiment was undertaken under the very conditions: the dosage of catalyst 2.0g/L, reaction time 2.0h, Ag loading of catalyst 1.0 at%, calcinations temperature 400°C and pH value 8.5.


2012 ◽  
Vol 518-523 ◽  
pp. 2213-2217 ◽  
Author(s):  
Jiang Yue Tan

In this paper, ultrasonic cavitation degradation was applied to treat the wastewater containing nitroaromatic compound. The factors influence to treatment effect such as the ultrasonic power and frequency, the wastewater initial pH value, were investigated by experiment. The experimental results showed that air-blasting in ultrasonic cavitation treatment could effectively improve treatment effect. The wastewater(COD:2650 mg•L-1,BOD5:240 mg•L-1,p-nitroaniline:490 mg•L-1,nitrobenzene:100 mg•L-1)was treated by ultrasonic cavitation degradation, the removal rate of p-nitroaniline,nitrobenzene and COD could be reached 91.3%,90.6% and 83.9% respectively after 3h. Biodegradability of the wastewater (B/C ratio ) can be increased to 0.4 , which satisfied the requirement for the subsequent biochemical processes.


2014 ◽  
Vol 955-959 ◽  
pp. 2449-2452
Author(s):  
Liu Hui Ru ◽  
Zhong Cai Hua ◽  
Feng Rui Jun

In this paper, the chitosan was prepared for treatment of electroplating wastewater. The influence of temperature, PH value, the amount of chitosan and mixing time on the effects of the wastewater treatment was investigated. The result showed that at PH=3, with the addition of 0.6g chitosan and 2h of mixing, the optimum wastewater treatment effect can be obtained. The removal rate of COD is above 80% and the adsorption rate of copper ion is above 99%. The decolourization ratio and the turbidity indicated that the treatment is effective.


2013 ◽  
Vol 295-298 ◽  
pp. 1307-1310
Author(s):  
Xi Tian ◽  
Ming Xin Huo ◽  
De Jun Bian ◽  
Sheng Shu Ai ◽  
Qing Kai Ren

The wastewater produced from the polytetrahydrofuran (PolyTHF) was treated with iron-carbon micro electrolysis process. This paper had studied the COD removal efficiency influences of primary PH value, reaction time, the quality ratio of the iron-carbon, the quality and volume ratio of Fe-wastewater. The results show that when pH value is 3, the quality ratio of the iron-carbon is 11 and the quality and volume ratio of Fe and wastewater is 17 with contact time of 90 min, the wastewater COD removal rate can reach as high as 95.0%.


2021 ◽  
Vol 287 ◽  
pp. 04006
Author(s):  
Patrick Tan Peng Jun ◽  
Wan Nur Aisyah Wan Osman ◽  
Shafirah Samsuri ◽  
Juniza Md Saad ◽  
Muhamad Fadli Samsudin ◽  
...  

Recent studies have shown great interest toward heavy metal removal due to its hazardous and non-biodegradable properties. Many approaches have been used for this purpose and one of them is adsorption. In this study, several experiments were carried out to investigate the feasibility of factory tea waste as a biosorbent in a fixed-bed adsorption column for heavy metal removal (zinc and copper) in wastewater. The results highlighted that zinc has better performance compared to copper in terms of the effect of initial ion concentration, pH value, and the mixed ions with respect to the removal efficiency. Zinc showed higher removal efficiency and adsorption capacity at the initial metal ion concentration of 200 mg/L, which are 99.21% and 39.68 mg/mg compared to copper. Meanwhile, for the effect of pH values and mixed ion concentration, zinc also showed slightly higher removal efficiency which are 99.91% and 98.47%, respectively compared to copper. However, both zinc and copper showed a better fit to the Langmuir isotherm. The factory tea waste was characterized using Micromeritics ASAP 2020 instrument and results showed that the factory tea waste biosorbent consists of mesopores with the diameter and width of 4.85205 and 2.546985 nm, respectively.


Author(s):  
Shuping Xu ◽  
Dandan Liu ◽  
Aihua Liu ◽  
Fu Sun ◽  
Shengying Pan ◽  
...  

Abstract A novel and facile rapid combustion approach was developed for the controllable preparation of small size and easy recovery magnesium-zinc ferrites for methyl blue (MB) removal in dye solution. The effects of prepared criteria of x value, calcination temperature, and the amount of ethanol on the average grain sizes and magnetic property were reviewed. The characterization results displayed that Mg0.5Zn0.5Fe2O4 nanoparticles met the expectations of the experiment at the calcination temperature of 400℃ with absolute ethanol volume of 20 mL, and they were selected to remove MB. The adsorption process belonged to chemical adsorption on the basis of the pseudo-second-order model. The electrochemical characteristics of MB onto the prepared nanoparticles were analyzed by cyclic voltammetry (CV). The influences of pH and cycle times on the removal efficiency were investigated. When the pH went beyond 3, the removal efficiency of MB onto the magnetic Mg0.5Zn0.5Fe2O4 nanoparticles maintained above 99%,the maximum adsorption capacity was 318.18 mg/g. After seven cycles, the relative removal rate of MB remained 96% of the first one.


2011 ◽  
Vol 347-353 ◽  
pp. 963-968
Author(s):  
Ping Hua Zhu

The sodium alginate fossilization Sphingomonas strains have double features: the biological absorption and biological degradation. And through using them to remove COD in the seawater we can see the pH value has highly significant impact on the removal rate, in addition, when the temperature is 37°C, pH value is 7.0, the pellet concentration is 1.0 g/L, the rotating speed is 120 r / min and oscillate for 90 min, the removal effect is the best. Pure strains, embedding micro-organisms have better removal efficiency of COD, indicating that microbes play a major role on the removal of COD, and microbial removal efficiency is the best after cultivated for 24 h, for microorganism is in the strongest logarithm phase at that time. However, the adsorption of COD mainly comes from functional groups on the surface of sodium alginate adsorption. The removal rate of COD in seawater treated by immobilized thallus can reach 86%, and can reach Class Ⅱseawater quality standards after purified. The study has the features of maintaining the multi-enzyme system of microbial cells, having less effect on microbial activity and also having obvious treatment effect; furthermore, its operation is simple, it requires less equipment and with lower prices.


2014 ◽  
Vol 609-610 ◽  
pp. 317-323
Author(s):  
Xiao Cai Yu ◽  
Dong Dong Hu ◽  
Jin Fang Chen ◽  
Yu Ying Wu ◽  
Xu Zheng

Zinc Oxide (ZnO) is a potential semiconductor as photocatalyst. Nevertheless, its main absorbance wavelength is in the range of UV light, which consist only a small proportion of solar. In order to utilizing the large proportion of solar light, pure ZnO and Li-doped ZnO nanoparticles with different Li loading (1.0, 2.0, 3.0 and 4.0 at%) and various calcination temperature (300, 500, 700, 900°C) were synthesized through a co-precipitation method and characterized by XRD and TEM techniques. The photocatalytic abilities of photocatalysts are evaluated in simulated experiments of removing diesel pollutants in seawater under visible illumination. Six factors, Li loadings, calcination temperature, dosage of photocatalyst, reaction time, diesel initial concentration, and pH value of seawater, were taken into consideration in the process of phtotcatalytic degradation of diesel experiments under visible light. An orthogonal experiment was implemented to investigate the best combination of five factors (the factor of reaction time was excluded) which can lead to the highest diesel removal rate. The characterization of as-prepared nano-particles showed that Li element was doped into ZnO, and all particles were of hexagonal wurtzite structure. The average crystal sizes of Li-doped ZnO with various calcination temperature (300, 500, 700 and 900°C) are 15.03, 25.97, 48.63 and 55.48nm, respectively, and consequently, higher calcination temperature will contribute to the aggregation of particles. Doping Li appropriately can improve the photocatalystic ability of ZnO under visible light, which can deduce from the single-factor experiments. Calcination temperature is also an evident factor to affect the photocatalytic ability of photocatalyst. The influence order of factors in decreasing order can also be obtain through the orthogonal experiment and the result was as follows: calcination temperature > Li loading ≈ pH value > initial concentration of diesel > photocatalyst dosage. The best combination of the five factors is as follows, the dosage of catalyst 2.5g/L, initial concentration of diesel 1.5g/L, Li loading of catalyst 1.0 at%, calcinations temperature 900oC and pH value 8.25, the removal rate of diesel pollutants in seawater is expected to reach 77.31%.


2012 ◽  
Vol 433-440 ◽  
pp. 793-797 ◽  
Author(s):  
Shao Xiu Li ◽  
Yu Qiang Lian ◽  
Jian Feng Mai ◽  
Jian Xiong Tan ◽  
Shu Jie Hu ◽  
...  

The threat of heavy metal pollution in water sources becomes increasingly serious. Toxic hexavalent chromium is harmful for health. Chitosan is a non-toxic and pollution-free substance, it is a cationic coagulant after protonated in diluted acid solution, it also can complex for many heavy metal ion. The study on removal of Cr (Ⅵ) and turbidity in drinking water by chitosan in this paper was performed. The results showed that the removal efficiency of Cr (Ⅵ) decreased with increasing pH, the removal rate of Cr (Ⅵ) was as high as 100% at pH4 using the chitosan concentration of 1.0g/L, but in these conditions, the turbidity was not removed. The removal efficiency of Cr (Ⅵ) bore relationship to stirring time of slow mixing step and initial concentration of Cr (Ⅵ). The best stirring time was 4 hours. To attain a good removal efficiency of Cr (Ⅵ), the dosage of chitosan must increase with the initial concentration of Cr (Ⅵ) increasing. At pH7, low chitosan dosage had good turbidity removal.


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