scholarly journals Characterisation of Electrochemical Sensor-Array for Utilisation in Construction of BOD Bioelectronic Tongue

2020 ◽  
Vol 24 (3) ◽  
pp. 39-54
Author(s):  
Kätlin Pitman ◽  
Jaak Nerut ◽  
Merlin Raud ◽  
Timo Kikas

AbstractThere is need to rapidly measure biochemical oxygen demand (BOD) to estimate organic pollution in wastewater. Biosensors are able to estimate BOD values within 5–30 minutes, but they have some limitations that can be overcome with biosensor-array. This work used sensor-array, which consists of 8 × 3 electrodes. The working electrode was inner Pt circle electrode, counter electrode was a Pt band electrode and the reference electrode was a silver wire. The potentiostat was used to record cyclic voltammetry and chronoamperometry. The pumping speed was set at 1.5 cm3 min−1 or higher, to avoid the interference. Next, sensor-array was tested to measure different oxygen amounts and calibrated accordingly. Lastly, Pseudomonas putida membranes were calibrated and used to estimate BOD value. The calibration gave linear range up to 85 mg L−1 of BOD and sensitivity from 0.0018 to 0.0068. Real industrial wastewater, from lignocellulosic bioethanol production, was used to test the biosensor-array. It underestimated BOD values from 8 to 37 %. This biosensor-array allows to measure BOD value in less than 15 minutes.

2019 ◽  
Vol 799 ◽  
pp. 197-202
Author(s):  
Alexander Usikov ◽  
Mike Puzyk ◽  
Sergey Novikov ◽  
Iosif Barash ◽  
Oleg Medvedev ◽  
...  

Treatment of graphene/SiC dies in inorganic electrolytes (KOH, KCl and Na2SO4) is discussed. An electrochemical method based on the cyclic voltammetry in a conventional three-electrode cell with Ag/AgCl reference electrode, a platinum counter electrode, and the graphene/SiC dies as working electrode (anode) is used for the treatment. It was observed either partial oxidation of graphene or its complete dissolution with the formation of CO2. The treatment performed resulted in the deterioration of the graphene films and change of the graphene-die resistivity depending on the range of the scanning potential applied to the graphene/SiC dies.


2014 ◽  
Vol 14 (2) ◽  
pp. 109-115
Author(s):  
Riyanto Riyanto ◽  
Ahmad Safarudin

Preparation and application of platinum composite microelectrode (PCM) for the routine analysis of acetaminophen in pharmaceutical products has been carried out. This electrode was prepare by Pt powder and PVC in 4 mL tetrahydrofuran (THF) solvent and swirled flatly to homogeneous followed by drying in an oven at 100 °C for 3 h. The mixture was placed in 0.5 cm diameter stainless steel mould and pressed at 10 ton/cm2. The cyclic voltammetry were performed in a three electrodes system using PCM as a working electrode, an Ag/AgCl (saturated KCl) as reference electrode and platinum wire as the counter electrode. Electroanalysis of acetaminophen was performed in 0.1 M H2SO4 as an electrolyte. The result of the study showed that the correlation of determination using PCM electrode for electroanalysis acetaminophen was R2 = 0.999. Precision, recovery, LOD and LOQ of the PCM towards acetaminophen were found to be 1.04%, 100.54%, 19.52 mg/L and 65.08 mg/L, respectively. As a conclusion, the methods can be used for routine analysis of acetaminophen in pharmaceutical product. Simplicity of sample preparation and use of low cost reagents are the additional benefit of this method.


2012 ◽  
Vol 15 (4) ◽  
pp. 289-292 ◽  
Author(s):  
Asim Yaqub ◽  
Huma Ajab ◽  
Mohamed Hasnain Isa ◽  
Hisyam Jusoh ◽  
Muhammad Junaid ◽  
...  

The effect of ultrasound (US) and electrode material on electrochemical treatment of industrial wastewater was studied. Samples were taken from three industries i.e. battery, ghee and tannery. Treatment efficiency was monitored by comparing the results of electrochemical and sonoelectrochemical processes in terms of metals and chemical oxygen demand COD removal. Experiments were performed in ultrasonic bath. In sonoelectrochemical process concentration of Pb decreased from 11.5 to 0.6 ppm at 80 kHz form battery industry. Similarly about 95 % removal of Cr (III) was observed from tannery wastewater using lead cathode. Titanium anode was found best counter electrode in metals removing. High COD removal was obtained by using steel anode at 80 kHz. Use of ultrasound is very effective in removing heavy metals and organic pollutants from industrial wastewater.


2014 ◽  
Vol 13 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Ghasem Najafpour Darzi ◽  
Reza Katal ◽  
Hossein Zare ◽  
Seyed Omid Rastegar ◽  
Poorya Mavaddat

1999 ◽  
Vol 39 (10-11) ◽  
pp. 221-224 ◽  
Author(s):  
Jana Zagorc-Končan ◽  
J. Šömen

Microbial purification capacity is an important factor in natural self-regulation in water. Evaluating the fate of biodegradable organic pollution downstream from the discharge seems an appropriate way to follow the effect of pollution and its hazard assessment, which dictates the needed sanitation measures. We suggest a simple test for such monitoring. A modification of the additional oxygen demand test, standardised in Ausgewählte Methoden der Wasseruntersuchung, was applied in two river case studies. The additional oxygen demand is a measure of the capability and rate of biodegradation of known organic substance as well as of the amount and activity of heterotrophic organisms in the river. The original test using peptone and glucose as additional feedings of BOD samples was modified by the use of other organic biodegradable model substances characteristic for individual industrial pollutants. The test was found to be an excellent indicator of adapted microorganisms, which are essential for the biodegradation of the appointed organic substances downstream of their discharge into the receiving stream.


2021 ◽  
Vol 10 (4) ◽  
pp. 46-51
Author(s):  
Tue Nguyen-Ngoc ◽  
Trung Nguyen-Duc

It can be seen that the objects of wastewater that need to be treated are quite diverse in types and complex in terms of reaction mechanisms. The methods mainly focus on the treatment of toxic organic compounds, especially phenols or plant protection agents in industrial wastewater, paper industry, food production, textile industry, printing industry... The activation of H2O2 and O2 by complexes of transitional metal ions and suitable ligands creates oxidizing agents and ecologically healthy products. The intermediate substances arising in the activation process such as free radicals OH., O2., HO2., ... can oxidize many compounds, especially the ability to attack the aroma of organic pollutants. In this paper, the results of research on treating organic pollution in restaurant wastewater with H2O2 are presented as a catalyst of complexes between Mn2+ ions and EDTA. The conditions including pH, EDTA/Mn2+, the concentration of H2O2, Mn2+ were investigated to obtain the optimum conditions for improving COD treatment efficiency. This work proposes a method based on formation of the Mn(II)-EDTA complex,  b=1; with the optimal conditions of other factors as following [H2O2]0 = 0,75.10-3 mol/L; [Mn(EDTA)]2- = 33,33 mol/L, pH=10.5; t = 15 minutes. The initial COD of 1025 mg/L decreased to 135 mg/L after the proposed procedure.  The results provide solutions of homogeneous complex catalysts for domestic/restaurant and industrial wastewater treatment at room temperature and atmosphere.


2015 ◽  
Vol 73 (4) ◽  
pp. 740-745 ◽  
Author(s):  
Jan Dries

On-line control of the biological treatment process is an innovative tool to cope with variable concentrations of chemical oxygen demand and nutrients in industrial wastewater. In the present study we implemented a simple dynamic control strategy for nutrient-removal in a sequencing batch reactor (SBR) treating variable tank truck cleaning wastewater. The control system was based on derived signals from two low-cost and robust sensors that are very common in activated sludge plants, i.e. oxidation reduction potential (ORP) and dissolved oxygen. The amount of wastewater fed during anoxic filling phases, and the number of filling phases in the SBR cycle, were determined by the appearance of the ‘nitrate knee’ in the profile of the ORP. The phase length of the subsequent aerobic phases was controlled by the oxygen uptake rate measured online in the reactor. As a result, the sludge loading rate (F/M ratio), the volume exchange rate and the SBR cycle length adapted dynamically to the activity of the activated sludge and the actual characteristics of the wastewater, without affecting the final effluent quality.


Author(s):  
A.E. Ogbeibu ◽  
S.I Ehiorobo

Water quality assessment was carried out within the 202 km2 Okomu National Park located within the 1,082km2Okomu Forest Reserve between January 2017 and December 2018. Water sampling was carried in ten compartments of approximately 1.6km2 each, covering Ponds, Stream and River, based on easy accessibility. No such study has been carried out for the Okomu Wetlands in the past three decades. Sampling protocols, laboratory analysis and quality control/quality assurance measures followed standard procedures. All physicochemical parameters showed significant (P < 0.001) spatial variations. The maximum and minimum values obtained for physicochemical parameters of the Okomu Wetland are 23.6 and 38.0°C air temperature; 21.0 – 38°C water temperature; 0.15 – 1.02m water level; 16.7 – 150.7mg/l total dissolved Solids (TDS); 0.5 – 18.8mg/l total suspended Solids (TSS); 0.2 – 14.8mg/l turbidity; 40. 0 – 307.4µS/cm electrical conductivity (EC); 4.4 – 6.7 pH; 0.02 – 0.14mg/l salinity; 0.7 – 5.5mg/l dissolve oxygen (DO); 0.5 – 3.8mg/l biochemical oxygen demand (BOD); 1.5 – 120.2mg/l chemical oxygen demand (COD); 23.8 – 593.6mg/l bicarbonates (HCO3); 69.9 – 245.3mg/l Chlorine (Cl); 0.02 – 0.59mg/l nitrite (NO2); 0.11 – 2.34mg/l nitrate (NO3); 0.04 – 2.11mg/l ammonium-nitrogen (NH4N); 0.05 – 2.96mg/l sulphate (SO4); 0.09 – 9.2mg/l phosphorus (P); 0.20 – 2.72mg/l sodium (Na), 0.03 – 1.32mg/l potassium (K); 0.88 – 5.88mg/l calcium (Ca); 0.13 – 3.1mg/l magnesium (Mg); 5.8 – 18.9mg/l iron (Fe); 0.04 – 1.1mg/l manganese (Mn); 0.02 – 0.09mg/l copper (Cu); 0.93 – 6.0mg/l zinc (Zn); 0.01 – 2.9mg/l lead (Pb); 0.01 – 0.18mg/l cadmium (Cd); 0.06 – 4.0mg/l chromium (Cr); 0.01 – 0.15mg/l nickel (Ni); 0.01 – 11mg/l vanadium (V). Air and water temperatures were mostly influenced by forest canopy cover. pH levels indicate that the water bodies within the forested wetland are slightly acidic. Higher DO values were recorded in the Arhakhuan Stream and Okomu River (Agekpukpu and Iron bridge) than in the temporary ponds. BOD levels of greater than 1mg/l were observed which is indicative of slight levels of organic pollution. Higher concentrations of TDS, TSS, turbidity, EC, Colour, HCO3, NH4N, NO2, NO3, P, Na, K, Ca Mg and heavy metals were recorded in the temporary ponds than in the Stream and River. Research on water bodies within wetlands should be carried out routinely in order to monitor changes in the water conditions that could occur overtime whether natural or anthropogenic. This becomes even more pertinent in the light of glaring impacts of climate change and increasing environmental modifications.


2011 ◽  
Vol 63 (3) ◽  
pp. 819-824 ◽  
Author(s):  
Dragana Milijasevic ◽  
Ana Milanovic ◽  
Jovana Brankov ◽  
M. Radovanovic

The Borska Reka river (47 km long, 373 km2 of basin area) is located in eastern Serbia and it is the biggest tributary of the river Veliki Timok. It is also one of the most polluted watercourses in Serbia. Using the data of the Republic Hydrometeorological Service of Serbia, the paper analyzes water pollution using the combined physical-chemical WPI index (water pollution index) over two periods: 1993-1996 and 2006-2009. The analysis of parameters showed significantly increased values of heavy metals (especially iron and manganese) which are indicators of inorganic pollution (primarily because of mining), but also increased values of organic pollution indicators (Biological Oxygen Demand-BOD5, ammonium, coliform germs), as the result of uncontrolled domestic wastewater discharge.


2017 ◽  
Vol 20 (2) ◽  
pp. 85
Author(s):  
Pawan Whig ◽  
Syed Naseem Ahmad ◽  
Surinder Kumar

In this paper, a novel circuit is presented which overcome a serious limitation found in case of multiple sensors system. In this novel system design only one reference electrode and few active components used that makes the implementation of a low-cost system for the supervision of water quality. Photo Catalytic Sensor (PCS) estimates the parameter BOD (Biological Oxygen Demand) which is generally used to estimate quality of water. The system proposed in this paper involves a balanced bridge approach using few electronic components that provides a correlation in the input-output signals of low-cost sensors. The main reason of employing a readout circuit to PCS circuitry, is the fact that the fluctuation of O2 influences the threshold voltage, which is internal parameter of the FET and can manifest itself as a voltage signal at output but as a function of the trans conductance gain. The trans-conductance is a passive parameter and in order to derive voltage or current signal from its fluctuations the sensor has to be attached to readout circuit. This circuit provides high sensitivity to the changes in percentage of O2 in the solution.


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