Effect of EM Techniques on Aquaculture Wastewater Purification

2015 ◽  
Vol 1092-1093 ◽  
pp. 838-843
Author(s):  
Long Wang ◽  
Ya Lu Shao ◽  
Li Hua Chen ◽  
Jie Liu ◽  
Xiao Hou Shao ◽  
...  

Through real-time monitoring of chemical oxygen demand (COD), ammonia nitrogen (NH4+-N), total nitrogen (TN) and total phosphorus (TP) in the aquaculture wastewater, the purification effects of EM techniques by applying EM active calcium, Microbial nanoSilica Ball and both of them were studied. The results showed that the purification effect of solid preparation for Microbial nanoSilica Ball was better than that of the liquid preparation for EM active calcium. Moreover, the purification effect with the technological cooperation of Microbial nanoSilica Ball with EM active calcium reached best, indicating that the removal rate of COD, NH4+-N, TN and TP in the aquaculture wastewater was 72.12% , 73.85% , 64.99% and 67.87% respectively.

2014 ◽  
Vol 955-959 ◽  
pp. 2187-2191 ◽  
Author(s):  
Long Wang ◽  
Xiao Hou Shao ◽  
Jian Qiang Mao ◽  
Xin Yu Mao ◽  
Chao Yin ◽  
...  

To form microbial nanoball, EM active calcium was immobilized on nano-silica carrier consisting of pond sediment, zeolite powder and nanosilica. Through real-time monitoring of pH, dissolved oxygen (DO), chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N) aquaculture wastewater, the purification effects of Microbial nanoSilica Ball on aquaculture wastewater under different mud-water ratio condition were studied. The results showed that the purification effect reached best in 3-6 days for all treatments and was better for mud-water ratio of 1:2.7. In this mud-water ratio, it was indicated that pH was maintained at 7-8.5 which was an optimum value for the aquaculture, the content of DO was increased by 82.16% compared with the initial value and the removal rate of COD and NH4+-N was 57.80% and 54.60% respectively.


2016 ◽  
Vol 73 (11) ◽  
pp. 2662-2669 ◽  
Author(s):  
Siyu Song ◽  
Jing Pan ◽  
Shiwei Wu ◽  
Yijing Guo ◽  
Jingxiao Yu ◽  
...  

The matrix oxidation reduction potential level, organic pollutants and nitrogen removal performances of eight subsurface wastewater infiltration systems (SWISs) (four with intermittent aeration, four without intermittent aeration) fed with influent chemical oxygen demand (COD)/N ratio of 3, 6, 12 and 18 were investigated. Nitrification of non-aerated SWISs was poor due to oxygen deficiency while higher COD/N ratios further led to lower COD and nitrogen removal rate. Intermittent aeration achieved almost complete nitrification, which successfully created aerobic conditions in the depth of 50 cm and did not change anoxic or anaerobic conditions in the depth of 80 and 110 cm. The sufficient carbon source in high COD/N ratio influent greatly promoted denitrification in SWISs with intermittent aeration. High average removal rates of COD (95.68%), ammonia nitrogen (NH4+-N) (99.32%) and total nitrogen (TN) (89.65%) were obtained with influent COD/N ratio of 12 in aerated SWISs. The results suggest that intermittent aeration was a reliable option to achieve high nitrogen removal in SWISs, especially with high COD/N ratio wastewater.


Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Ilaria Piccoli ◽  
Giuseppe Virga ◽  
Carmelo Maucieri ◽  
Maurizio Borin

Constructed wetlands (CWs) represent a green technology for digestate liquid fraction (DLF) treatment. However, previous research has warned about their performance when treating wastewater with high suspended solid and organic loads. In addition, the high NH4-N concentration typical of this wastewater can compromise vegetation establishment and activity. In view of this, a digestate pretreatment is needed. This study aimed to test the performance of filters filled with recovery materials, such as brick and refractory material, for DLF pretreatment. The effect on DLF physical (electrical conductivity, pH, dissolved oxygen, and temperature) and chemical (total nitrogen, ammonia–nitrogen, nitrate–nitrogen, total phosphorus, soluble phosphorus, and chemical oxygen demand) characteristics was monitored during eight weekly cycles. The effect of filtration on total nitrogen and ammonia–nitrogen removal began after about one month of loading, suggesting that an activation period is necessary for bacteria. For effective N removal, the presence of multiple digestate recirculations per day through the filters appears mandatory to guarantee the alternation of nitrification and denitrification conditions. For P removal, filling material particle size appeared to be more important than its composition. Unclear performances were observed considering chemical oxygen demand. Further studies on filling media and microbial community interactions, and the long-term efficiency of filters, are desirable.


2016 ◽  
Vol 15 (4) ◽  
pp. 23-34 ◽  
Author(s):  
F T Z Jabeen ◽  
J V Shreevathsa

This study was designed to investigate the fungi associated with palm oil mill effluent (POME) in Gulur village of Tumkur. Biodegradation of palm oil mill effluents was conducted to measure the discarded POME based on physicochemical quality. The fungi that were isolated are Aspergillusniger, A. flavus, A. fumigatus, A. ochraceus, Rhizopussp, Peniciliumsp and Trichodermavirde. The autoclaved and unautoclaved raw POME samples were incubated for 7 days and the activities of the fungi were observed each for 12 hours. The supernatants of the digested POME were investigated for the removal of chemical oxygen demand (COD), color (ADMI), and biochemical oxygen demand (BOD) at the end of each digestion cycle. The results showed that the unautoclaved raw POME sample degraded better than the inoculated POME sample and this suggests that the microorganisms that are indigenous in the POME are more effective than the introduced micro-organisms. This result, however, indicates the prospect of isolating indigenous microorganisms in the POME for effective biodegradation of POME. Moreover, the effective treatment of POME yields useful products such as reduction of BOD, COD, and color.


2020 ◽  
Vol 49 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Wei Zhang ◽  
Weiwei Lv ◽  
Xiaoyan Li ◽  
Jiming Yao

Purpose In this study, the oxidative degradation performance of indigo wastewater based on electrochemical systems was explored. The decolourization degrees, removal rate of chemical oxygen demand and biochemical oxygen demand of the indigo wastewater after degradation were evaluated and optimized treatment conditions being obtained. Design/methodology/approach The single factor method was first used to select the electrolyte system and electrode materials. Then the response surface analysis based on Box–Behnken Design was chosen to determine the influence of four independent variables such as FeCl3 concentration, NaCl concentration, decolourization time and voltage on the degradation efficiency. Findings On the basis of single factor experiment, the electrode material of stainless steel was selected in the double cell, and the indigo wastewater was electrolyzed with FeCl3 and NaCl electrolytes. The process conditions of electrochemical degradation of indigo wastewater were optimized by response surface analysis: the concentration of FeCl3 and NaCl was of 16 and 9 g/L, respectively, with a decolourization time of 50 min, voltage of 10 V and decolourization percentage of 98.94. The maximum removal rate of chemical oxygen demand reached 75.46 per cent. The highest ratio of B/C was 3.77, which was considered to be more biodegradable. Research limitations/implications Dyeing wastewater is bringing out more and more pollution problems to the environment. However, there are some shortcomings in traditional technologies such as adsorption and filtration. As a kind of efficient and clean water treatment technology, electrochemical oxidation has been applied to the treatments of various types of wastewater. The decolourization and degradation of indigo wastewater is taken as an example to provide reference for the treatment of wastewater in actual plants. Practical implications The developed method provided a simple and practical solution for efficiently degrading indigo wastewater. Originality/value The method for the electrochemical oxidation technology was novel and could find numerous applications in the degradation of printing and dyeing wastewater.


RSC Advances ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 6452-6459 ◽  
Author(s):  
Guangzhi Xin ◽  
Min Wang ◽  
Lin Chen ◽  
Yuzhou Zhang ◽  
Meicheng Wang ◽  
...  

A novel adsorbent zeolite/N-doped porous activated carbon (ZAC) was prepared by the synthesis of zeolite and mesoporous carbon to remove ammonia nitrogen (NH4+–N) and chemical oxygen demand (COD) from aqueous solution.


2013 ◽  
Vol 461 ◽  
pp. 544-552 ◽  
Author(s):  
Hong Peng Guo ◽  
Gan Yu Feng ◽  
Chun Xia Liu ◽  
Xiao Yi Zhang

Nearly 40% of Chinese water pollution comes from agricultural sources of pollution, and the annual emissions are difference. If we want to control pollution emissions effectively, we need to accurately predict the amount of agricultural emissions of Ammonia Nitrogen (AN) and Chemical Oxygen Demand (COD). Due to the complex mechanism of the agricultural non-point source pollution, its emissions are very difficult to measure. Currently, the Bionics Research is in a stage of rapid development, and it continues to expand into many new areas of research. So the comprehensive study of Bionics and pollutant control study will be a good choice. This research used bionic BP(Back Propagation) neural network algorithm, and used pollution census data from 2002 to 2007 and established neural network model with neural network algorithm. And we predicted the agricultural sources of emissions of AN and COD with the data from 2008 to 2010. Finally we compared the predicted value and the actual value. Research results showed that, with using the bionic BP neural network, agricultural sources emissions of AN and COD are evaluated actually and the results indicate that the average error is under 5.0%. Research results proved that the model is effective. The neural network is a scientific predict method for the agricultural sources emissions of AN and COD. It can be widely used in the prediction of agricultural sources emissions of AN and COD.


2011 ◽  
Vol 239-242 ◽  
pp. 2597-2601
Author(s):  
Wei Ding ◽  
Ming Ke ◽  
Zhao Zheng Song

Anthraquinone dye Reactive Blue (KN-R) is first selected as the model dye to test the treatment of UV-vis/Ferrioxalate/H2O2system. The effect of parameters Fe2+/H2O2, pH and H2C2O4are synthetically assessed. The optimum concentration is obtained at 1:15 of Fe2+/H2O2and 30mg·L-1of H2C2O4 at pH=3.0 in 30min. Under the optimum condition, the removal rate of color, chemical oxygen demand (COD) and total organic carbon (TOC) are more than 99%, 87.7% and 66.8% respectively. The results show that the reaction accorded with a pseudo-first-order and the degeneration velocity of KN-R is 0.2459[dye](mg·L-1/min).


2013 ◽  
Vol 726-731 ◽  
pp. 4095-4100
Author(s):  
Rong Rong Xie ◽  
Yong Pang

To redress the deteriorating environment, policies regarding river eco-compensation have been issued in China since 2008. Due to the high cost, eco-compensation has not been well implemented in the Taihu pilot region. Therefore, how to determine the compensation criterion is already a priority. In this paper, a compensation criterion model based on the treatment costs of sewage was introduced. Using the pollution source census data covering 2007, 2009, 2010 and 2011 in the Taihu lake area of Jiangsu province, the average eco-compensation criterion for chemical oxygen demand (COD) is 2,000 Chinese Yuan (CNY) ± 325 CNY per ton and ammonia nitrogen (NH4-N) and total phosphorus (TP) are 8,000 CNY ± 1,300 CNY and 80,000 CNY ± 13,000 CNY per ton, respectively. The new method can provide an important template for managers when drafting river eco-compensation schemes.


2012 ◽  
Vol 66 (6) ◽  
pp. 1220-1224
Author(s):  
Suwasa Kantawanichkul ◽  
Walaya Boontakhum

In this study, the effect of dosing regime on nitrification in a subsurface vertical flow treatment wetland system was investigated. The experimental unit was composed of four circular concrete tanks (1 m diameter and 80 cm deep), filled with gravel (1–2 cm) and planted with Cyperus alternifolius L. Synthetic wastewater with average chemical oxygen demand (COD) and ammonia nitrogen of 1,151 and 339 mg/L was fed into each tank. Different feeding and resting periods were applied: continuous flow (tank 1), 4 hrs on and 4 hrs off (tank 2), 1 hr on and 3 hrs off (tank 3) and 15 minutes on and 3 hrs 45 minutes off (tank 4). All four tanks were under the same hydraulic loading rate of 5 cm/day. After 165 days the reduction of total Kjeldahl nitrogen and ammonia nitrogen and the increase of nitrate nitrogen were greatest in tank 4, which had the shortest feeding period, while the continuous flow produced the lowest results. Effluent tanks 2 and 3 experienced similar levels of nitrification, both higher than that of tank 1. Thus supporting the idea that rapid dosing periods provide better aerobic conditions resulting in enhanced nitrification within the bed. Tank 4 had the highest removal rates for COD, and the continuous flow had the lowest. Tank 2 also exhibited a higher COD removal rate than tank 3, demonstrating that short dosing periods provide better within-bed oxidation and therefore offer higher removal efficiency.


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