scholarly journals Laboratory simulation of dissolved oxygen reduction and ammonia nitrogen generation in the decay stage of harmful algae bloom

Author(s):  
Qiaoning Wang ◽  
Xiaodong Li ◽  
Tian Yan ◽  
Jingjing Song ◽  
Rencheng Yu ◽  
...  
Fishes ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 20
Author(s):  
Jie Cao ◽  
Qi Wang ◽  
Jun Mei ◽  
Jing Xie

This study evaluated the effect of different concentrations (20, 40 and 60 mg/L) of 3-aminobenzoic acid ethyl ester methanesulfonate (MS-222) on the quality changes in turbot during simulated transport in water. The results showed that the ammonia nitrogen content in the transportation water of each sample increased significantly, and the dissolved oxygen level decreased. The dissolved oxygen content in MS-222-treated samples was higher than that of control group (CK) samples. For turbot flesh quality, simulated transport in water led to a decrease in moisture, fat and protein contents in all samples. The MS-222-treated turbot samples showed higher pH values, glycogen contents, springiness and chewiness values and lower lactic acid contents comparing with the CK samples during simulated transport in water. In addition, the fresh and bitter amino acids in the muscle of turbot increased in each treatment group compared to the non-transported fish at the end of the simulated transport. The results showed that MS-222 treatment could retard the turbot transport stress and improve the quality of turbot during simulated transport in water.


2015 ◽  
Vol 752-753 ◽  
pp. 232-237
Author(s):  
Rafidah binti Hamdan ◽  
Izzati Izwani Ibrahim ◽  
Ain Nabila Abdul Talib

Nitrogen is a naturally occurring element that is essential for growth and reproduction in both plants and animals. Excessive concentrations in the water body can cause excessive growth of algae and other plants, leading to accelerate eutrophication of lakes, and occasional depletion of dissolved oxygen. To remove nitrogen conventionally from domestic wastewater requires a high cost technology due to consumption of chemicals, high operational and maintenance cost. Therefore, an alternative low cost treatment technology particularly for nutrient removal including nitrogen removal system has been developed to improve the final effluent quality that is an aerated rock filter system. However, the optimization study under warm climate has not yet been developed. Hence, the present study was carried out to investigate the removal of ammonia nitrogen (AN) from domestic wastewater through nitrification process using a lab-scale vertical aerated limestone filter. Domestic wastewater sample used in this study was collected from Taman Bukit Perdana Wastewater Treatment Plant (WWTP), Batu Pahat, Johor owned by IWK. The experiment has been carried out for 10 weeks. The influent and effluent of the vertical aerated limestone filter system have been sampled and analyzed on biweekly basis for selected parameters including AN, Total Kjedhal Nitrogen (TKN), pH, alkalinity, temperature and dissolved oxygen to monitor the effectiveness of the filter. Results from this study show that nitrification process has took place within the aerated limestone filter as the results from laboratory experiments show that AN in wastewater was oxidized to nitrate and efficiently removed as the removal of AN was ranged from 85 % to 92 % and the removal percentage of TKN was ranged from 83.52 % - 91.67 %. The temperature was in the average of 26.3oC±0.75, pH value average of , DO was from 6.64 mg/L to 7.75 mg/L , and the alkalinity was from 15 to 110 mg / l as CaCO3 . Therefore, from this study it can be concluded that aerated rock filter system has high potential in removing AN and TKN. It is also able to produce a good final effluent quality which is comply with the effluent requirement for nutrient removal in wastewater under the Environmental Quality Act (Sewage) Regulations, 2009 that is safe to be released to the water body.


2013 ◽  
Vol 1 (1) ◽  
pp. 48
Author(s):  
ABM Mohsin ◽  
Roni Chandra Mondal

The behaviour of fourteen exotic ornamental fishes of Bangladesh under starved condition in aquaria was experimented from January to December, 2011. Fishes were belonging to 13 genera, 09 families and 4 orders. Two treatments each with three replications were used. Four different behavioural phases of fish were monitored through constant observation. Almost all the behavioural phases were seen earlier in the fishes of treatment T1. Marble angel survived more (1022±4.02 hrs; T2) than others. The lowest survival period (116±2.44 hrs; T1) was seen for albino suckermouth. Fishes were died earlier in T1 than T2, due to presence or absence of aeration facilities. Water temperature, dissolved oxygen, free CO2, pH, total alkalinity, ammonia-nitrogen and chlorine level were found to be varied from 25.66±0.17 to 28.66±0.35°C, 3.80±0.06 to 4.73±0.07 mg/l, 9.21±0.05 to 11.75±0.03 mg/l, 7.13±0.05 to 7.47±0.07, 76.66±1.64 to 108.92±3.20 mg/l, 0.0010±0.0006 to 0.0133±0.002 mg/l and 0.0045±0.001 to 0.012±0.0014 mg/l, respectively. The research findings would be helpful in gathering basic knowledge on different behavioural phases through which aquarists can maintain primitive behavioural phase in their aquaria.  Further research work is suggested in the aforesaid theme massively.


2014 ◽  
Vol 1010-1012 ◽  
pp. 635-638
Author(s):  
Yan Juan Xi ◽  
Zhen Liang Zhao ◽  
Chun Long Zhao ◽  
Yan Qin Xi ◽  
Li Yan ◽  
...  

Based on the environmental survey data in off-shore of Qin Huangdao from May to June 2011,correlation analysis was made between population density of Noctiluca scintillans and environmental factors. The results indicates that population density of Noctiluca scintillans does not exist linear correlation with nitrite, nitrate, ammonia, nitrogen, phosphate,dissolved oxygen and PH ,it is positive correlation with temperature and silicate noctiluca and negatively correlation with transparency and salinity.


2000 ◽  
Vol 42 (1-2) ◽  
pp. 337-340 ◽  
Author(s):  
H.Q. Shaheen

Wastewater flow samples were collected at 2-hour intervals for one week during the month of October 1998 at the Irtah wastewater pumping station in the Tulkarem city. The station collects about 32% of the wastewater of the Tulkarem city and 25% of the Tulkarem camp. The samples were mixed on 24-hour basis and tested for the pollution parameters BOD5, COD, total suspended solids, orthophosphate, total Kjeldahl nitrogen, ammonia nitrogen, nitrate, calcium, sodium and potassium. At the 2-hour intervals the wastewater flow was tested for conductivity, temperature, pH, and dissolved oxygen. The variation of the strength of these parameters and its relation to the flow values are observed and evaluated. The produced organic strength versus the flow and the 24-hour mixed samples are presented and commented upon.


2010 ◽  
Vol 98 (3-4) ◽  
pp. 229-234 ◽  
Author(s):  
V. Rodríguez-González ◽  
S. Obregón Alfaro ◽  
L.M. Torres-Martínez ◽  
Sung-Hun Cho ◽  
Soo-Wohn Lee
Keyword(s):  

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yanhao Zhang ◽  
Lilong Huang ◽  
Zhibin Zhang ◽  
Cuizhen Sun ◽  
Jixiang Li

To evaluate the actual performance of the H2-based polyvinyl chloride hollow fiber membrane biofilm reactor (HF-MBfR), we used HF-MBfR to remove nitrate from the nitrate contaminated groundwater with the dissolved oxygen (~6.2 mg/L) in Zhangqiu city (Jinan, China). The reactor was operated over 135 days with the actual nitrate contaminated groundwater. The result showed that maximum of nitrate denitrification rate achieved was over 133.8 gNO3--N/m3d (1.18 gNO3--N/m2d) and the total nitrogen removal was more than 95.0% at the conditions of influent nitrate 50 mg/L, hydrogen pressure 0.05 MPa, and dissolved oxygen (DO) 6.2 mg/L, with the nitrate in effluent under the value limits of drinking water. The fluxes analysis showed that the electron-equivalent fluxes of nitrate, sulfate, and oxygen account for about 81.2%, 15.2%, and 3.6%, respectively, which indicated that nitrate reduction could consume more electrons than that of sulfate reduction and dissolved oxygen reduction. The nitrate reduction was not significantly influenced by sulfate reduction and the dissolved oxygen reduction. Based on the actual groundwater quality on site, the Langelier Saturation Index (LSI) was 0.4, and the membrane could be at the risk of surface scaling.


Sign in / Sign up

Export Citation Format

Share Document