scholarly journals Removal Efficiency of Nitrite and Sulfide Pollutants by Electrochemical Process by Using Ti/RuIrO2 Anode

2018 ◽  
Vol 18 (2) ◽  
pp. 286 ◽  
Author(s):  
Aris Mukimin ◽  
Agus Purwanto
Keyword(s):  
Removal Efficiency ◽  
Hydraulic Retention Time ◽  
Oxidation Mechanism ◽  
Electrochemical Process ◽  
Anode Surface ◽  
Electrochemical Technology ◽  
Nitrite Removal ◽  
Biological Methods ◽  
Operation Cost ◽  
Easy Operation

In general, wastewater treatment by physical, chemical and biological methods are only focused on TSS, BOD and COD removals that the effluent still contains anion pollutant as NO2- and S2-. Electrochemical technology is a proper method for those pollutants treatment due to its fast process, easy operation and minimum amount of sludge. Electrocatalytic reactor with 8 L capacity using Ti/RuIrO2 cylinder as anode and Fe plate as cathode was arranged and applied to treat anion pollutants. Hydraulic retention time (30, 60, 90 and 120 min), salt concentration (250, 500 and 750 mg/L) and voltage (4, 5, and 6 V) were chosen as operation variables and NO2- and S2- concentrations as parameter indicators. Nitrite removal efficiency reached 75 and 99.7% after 60 and 120 min of electrolysis, respectively, while sulfide could obtain higher efficiency, i.e., 97 and 99.9% after 60 and 90 min, respectively, at operation variables of potential of 5 V and salt of 500 mg/L. Removal process is dominated by indirect oxidation mechanism by HClO/ClO- oxidators generated at anode surface as intermediate products. The lifespan of electrode and electric consumption are two main factors of operation cost. Electric consumed was 0.452 kWh per 1 g nitrite removed.

An electrochemical mechanisms study on steel/IrO2–Sb2O3 electrodes for oxidation of phenol in water

2015 ◽  
Vol 93 (5) ◽  
pp. 536-541
Author(s):  
Pavithra Bhakthi Jayathilaka ◽  
Gayani Chathurika Pathiraja ◽  
Athula Bandara ◽  
Nalaka Deepal Subasinghe ◽  
Nadeeshani Nanayakkara
Keyword(s):  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Hydroxyl Radicals ◽  
Oxygen Demand ◽  
Oxidation Mechanism ◽  
Constant Current ◽  
Anode Surface ◽  
Radical Scavenger ◽  
Chemical Oxygen Demand Removal ◽  
Constant Current Density

Phenol, a known water pollutant, was electrochemically oxidized on a steel/IrO2–Sb2O3 novel anode. Since the oxidation mechanisms vary based on the anode material, a mechanisms study of electrooxidation of phenol on it was conducted. The phenol oxidation was carried out at 20 mA/cm2 constant current density with a pH 11.00 Na2SO4 medium at room temperature. During 6 h of electrolysis, samples were tested for chemical oxygen demand removal efficiency of the anode. The steel/IrO2–Sb2O3anode showed 76.3% chemical oxygen demand removal efficiency. Both 4-nitroso-N,N-dimethylaniline and the HCO3–/CO32– radical scavenger tests confirmed the formation and presence of the hydroxyl radicals in the system. Therefore, it was concluded that the hydroxyl radicals that are generated on the anode surface are the main cause for the oxidation mechanism. Moreover, ICE, HPLC, and UV-vis absorbance and cyclic voltammetry results confirmed the presence of catechol and benzoquinone as intermediates and the reaction mechanism.

Evaluation of a tropical single-cell waste stabilization pond system for irrigation

1995 ◽  
Vol 31 (12) ◽  
pp. 267-273 ◽  
Author(s):  
B. S. O. Ceballos ◽  
A. Konig ◽  
B. Lomans ◽  
A. B. Athayde ◽  
H. W. Pearson
Keyword(s):  
Single Cell ◽  
Removal Efficiency ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Full Scale ◽  
Waste Stabilization Pond ◽  
North East ◽  
Helminth Eggs ◽  
Waste Stabilization ◽  
Better Than

A single full-scale primary facultative pond in Sapé, north-east Brazil was monitored for performance and efficiency. The pond had a hydraulic retention time of 61 days and achieved a 95% BOD5 removal efficiency and had no helminth eggs in the effluent. The effluent failed to meet the WHO faecal coliform guideline for unrestricted irrigation. The pond was dominated by the cyanobacterium Microcystis and gave better than predicted orthophosphate removal. Details of how the system could be simply upgraded utilizing the same land are discussed.

scholarly journals Treatment Of Tofu Industry Wastewater Using Bioreactor Anaerobic-Aerobic And Bioball As Media With Variation Of Hidraulic Retention Time

REAKTOR ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 18-25
Author(s):  
Ariani Dwi Astuti ◽  
Dewi Intania Ayu
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Negative Impact ◽  
Low Cost ◽  
Industrial Effluent ◽  
Organic Loading Rate ◽  
High Concentration ◽  
Small Industries

Tofu which is made by grinding soy bean, generates huge amount of wastewater and thus considered as one of the most polluted food-industrial effluent owing to its high values of organic contents. The small industries of tofu preparation process release the wastewater directly into the water body without being treated first. Prior to discharge this wastewater into the waterbody, the wastewater must be treated to reduce the possibility of negative impact and the contamination of the waterbody. For these small industries, the best alternative of wastewater treatment is one which has the following criteria: easy in operation, low cost operation, low volumes of sludge produced, and can be used in high concentration wastewater. In this research, bioreactor anaerobic-aerobic with media bioball is used. The highest removal efficiency of COD took place in anaerobic zones. Bioreactors were operated with the variations of retention time at 24 hours, 18 hours, and 12 hours. The COD removal efficiency for Hydraulic Retention Time (HRT) of 24 hours, 18 hours and 12 hours were found 90.3% (organic loading rate is 15.1 kg COD/m3.day), 84.4% and 76.3% respectively. The experiment showed that the longer of the hydraulic retention time (HRT), the higher the removal efficiency could be achieved. These occurred because a longer HRT will extend the contact time between wastewater and microorganisms attached. Therefore, microorganisms have a longer time to degrade organic matter in wastewater. Although the removal efficiency in these three-HRT was found high, the effluent of the reactor was still above the effluent standard based on regulation of Ministry of Environmental Permen LH No. 5/2014. Kinetics using Eckenfelder Equation results R2 equal to 0.9991, n equal to 0.293 and K equivalent to 7.3577 mg/L. Keywords: tofu wastewater, anaerobe, aerobe, bioball, wastewater, treatment, attached growth

Membrane Filtration Combined with Biological Treatment for Purification of Bleach Plant Effluents

1991 ◽  
Vol 24 (3-4) ◽  
pp. 219-228 ◽  
Author(s):  
B. Boman ◽  
M. Ek ◽  
W. Heyman ◽  
B. Frostell
Keyword(s):  
Biological Treatment ◽  
Membrane Filtration ◽  
Hydraulic Retention Time ◽  
Kraft Pulping ◽  
Fungal Flora ◽  
Anaerobic Filter ◽  
Microtox Test ◽  
Biological Methods ◽  
Aox Removal ◽  
Chlorinated Phenolic Compounds

A bleach plant effluent from softwood kraft pulping was treated in the laboratory with a combination of ultrafiltration and different biological methods. The E-stage effluent was firstly membrane filtered using membranes with a nominal cut-off of 8,000 Dalton. In the filtration, a concentration factor of 15 was used at 55°C. The treatment resulted in 89% AOX removal and 87% COD removal. Calculated in relation to the actual flows of E-stage and (C+D)-stage effluent at the mill, this corresponded to AOX and COD removals of 20% and 41% respectively. Before the biological treatment, the permeate was mixed with (C+D)-stage effluent and treated in three parallel biological systems, an aerated lagoon with and without solids recycle, an airlift system with a mixed fungal flora and an anaerobic filter. For the lagoon treatment, a hydraulic retention time of 7 days was used at biomass concentrations of 70, 350 and 480 mg TSS/l and 20-22°C. The fungal system was evaluated at retention times of 5.5 11 and 22 h, 770 mg TSS/l and 37°C. For the anaerobic filter, retention times of 1, 5 and 25 h at a temperature of 35°C were used. Very promising results were obtained with the combination of physical and biological treatment. The aerated lagoon with solids recycle gave the best results with 66% of AOX, 72% of COD and 95% of the BOD being removed in the combined process. The anaerobic filter also gave good results, but in practice a small aerobic post-treatment would probably be necessary. The three systems were also evaluated for the removal of chlorinated phenolic compounds and acute toxicity according to the Microtox test. The results suggest that a combination of membrane filtration and anaerobic/aerobic or just aerobic treatment would be an attractive way to handle kraft mill bleach plant effluents.

Biodegradation of DBP by Biofilm Reactor

2012 ◽  
Vol 178-181 ◽  
pp. 390-399 ◽  
Author(s):  
Jian Yu ◽  
Yu Fu ◽  
Ming Jie Jiang ◽  
Wen Hui Ren
Keyword(s):  
Kinetic Model ◽  
Removal Efficiency ◽  
Phthalic Acid ◽  
Dibutyl Phthalate ◽  
Hydraulic Retention Time ◽  
Degradation Products ◽  
Biofilm Reactor ◽  
Metabolic Intermediate ◽  
Environmental Hormone ◽  
Positive Effect

The removal efficiency of dibutyl phthalate (DBP) and its environmental hormone treated by biofilm reactor has been investigated. Besides, the the kinetic model of the degradation of DBP and its degradation products in the reactor have been discussed. The results indicate that the biofilm reactor had a positive effect on the removal of DBP and was able to significantly reduce the environmental hormone in DBP influent. The activity of β-galactosidase dropped from 13.55 millers to 3.3 millers and the removal efficiency of DBP reached 98.5% at water temperature 20°C and HRT (Hydraulic Retention Time) of 4 hours. The metabolic intermediate of DBP in the reactor mainly consisted of dibutyl phthalate and phthalic acid. The kinetic models of the degradation of DBP can be expressed by Lawrence-McCarty equation.

Study on Denitrification and Phosphorus Removal Using an Integrated A/O Trickling Filter

2011 ◽  
Vol 183-185 ◽  
pp. 819-823
Author(s):  
Ying Kuang ◽  
Qi Rong Dong ◽  
He Li Wang
Keyword(s):  
Carbon Source ◽  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Trickling Filter ◽  
Biological Methods

Two columns were experimented to compare trickling filter with integrated A/O trickling filter (IA/OTT) in this study. Denitrification and phosphorus removal were limited in traditional trickling filter. By designing anoxic section, adding carbon source and recycling outflow, denitrification was enhanced in IA/OTT. Meanwhile, chemical-biological methods were used to improve the phosphorus removal. It was shown that removal efficiency of CODcr, NH3-N, TN and TP were ideal. Compared with the traditional trickling filter, especially, the removal efficiency of TN and TP were respectively about 35% and 50% higher.

scholarly journals MIKROORGANISME PATOGEN DAN PARASIT DI DALAM AIR LIMBAH DOMESTIK SERTA ALTERNATIF TEKNOLOGI PENGOLAHAN

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Nusa Idaman Said ◽  
Ruliasih Marsidi
Keyword(s):  
Pathogenic Bacteria ◽  
Hydraulic Retention Time ◽  
Suspended Solid ◽  
Nitrogen And Phosphorus ◽  
Domestic Waste ◽  
Air Supply ◽  
Circulation Ratio ◽  
Inorganic Content ◽  
Parasitic Worms ◽  
Operation Cost

Domestic waste are known to be a potential pollutant due to its’ organic and inorganic content. It is also harmful for society for its pathogenic microorganism contents such as pathogenic bacteria, viruses, parasitic worms, parasitic protozoa, etc. The lack of domestic waste processing facilities is contributing to the increasing seriousness of this matter.One of the alternative ways to amend the problem is to process the waste individually or semi-communally by utilizing an aerobic-anaerobic biofilter process. Some of the advantage of utilizing this process is: easy maintenance, low operation cost, relatively lower sludge compared to the activated sludge  process, can remove nitrogen and phosphorus, relatively lower air supply requirement for aeration, applicable in processing waste water with large amount of BOD and it can also remove suspended solid (SS).  Results gained from experiments of the “Aerobic-Anaerobic Biofilter Combination” tool prototype, used for processing domestic waste showed that with a hydraulic retention time of 1 to 3 days and a Hydraulic   re-circulation ratio (HRR) of 1, is a highly efficient process which is: BOD 84.7% - 91%, COD 79.6%-95.3%, SS 94.1% - 95%, Ammonia (NH4-N) 89.3%-89.8%, Detergent (MBAS) 83% - 87% and phosphate (PO4) 44,4% - 47.3%. Kata kunci : Air limbah domestik, patogen, parasit, biofilter, anaerob, aerob. 

scholarly journals Performance of different biofilters in a recirculating system for rainbow trout farming

2016 ◽  
pp. 5426-5440 ◽  
Author(s):  
Iván Sánchez O ◽  
Dolly Revelo R ◽  
Álvaro Burbano M ◽  
Roberto García C ◽  
Camilo Guerrero R ◽  
...  
Keyword(s):  
Suspended Solids ◽  
Hydraulic Retention Time ◽  
Nitrate Removal ◽  
Flow Distribution ◽  
Chemical Parameters ◽  
Recirculating Aquaculture ◽  
El Sistema ◽  
Solids Retention ◽  
Nitrite Removal ◽  
Solids Removal

Objective. To evaluate the performance of different biofilters in a recirculating aquaculture system (RAS) for trout farming. Materials and methods. It was used a 1m3 plastic tank for fries farming; fabric bags to solids retention; a submersible pump; a constant water level and flow distribution box; six up flow biofilters in 3” PVC tube; sand of D10=0.45mm as carrier. The reactors were operated at local temperature and with hydraulic retention time (HRT) of 11 min, the biofilters were inoculated in the next way: R1-Control: RAS water; R2-Fish culture farm sludges; R3- Water from aerated lagoon of Antanas landfill (AL); R4-Aquarium sediments; R5- Aerated lagoon of AL sludges; R6-Sludges from sulfidogenic reactor of AL. The weight gain (WG) and the food conversion (FC) were evaluated, some physic-chemical parameters were monitored and the nitrogen and suspended solids removal efficiency were evaluated. Results. The WG of the cultured animals was 1.58 g/d and the FC was 1.41. There were no differences for ammonium and nitrite removal between the reactors; the average removal efficiencies were: ammonium 4.78%, nitrite 27.2%, nitrate 32.3%, suspended solids 37.5%; R4 and R5 reactors presented the best performance on nitrate removal, with average efficiencies of 47.4% and 42.8%. R3 presented the best SS removal with an average of 58.2%. Conclusions. The RAS water treatment system guaranteed appropriated liquid quality conditions for trout farming; the most efficient reactor for removal of the different forms of nitrogen was the inoculated with the aerated lagoon of AL sludges.RESUMEN Objetivo. Evaluar el desempeño de diferentes biofiltros en un sistema de recirculación (SRA) para cultivo de trucha arcoiris. Materiales y métodos. Se utilizó: un tanque de 1m3 para cultivo de alevines, bolsas de lienzo para retención de sólidos, bomba sumergible, caja de nivel constante y distribución de flujo, seis biofiltros en tubo de PVC de 3”, arena con D10=0.45mm como medio soporte. Los biofiltros se operaron a temperatura ambiente y con tiempo de retención hidráulica (TRH) de 11 min, se inocularon así: R1-Control: Aguas del SRA; R2-Lodos estación piscícola; R3-Agua Laguna aireada relleno sanitario Antanas (RSA); R4-Sedimentos acuarios; R5-Lodos laguna aireada RSA; R6-Lodos reactor sulfidogénico RSA. Se evaluó la ganancia de peso (GP) y la conversión alimenticia (CA), se monitorearon parámetros físico-químicos y se evaluó la eficiencia de remoción de nitrógeno y sólidos suspendidos. Resultados. La GP de los animales fue de 1.58 g/d y la CA de 1.41. No hubo diferencias para remoción de amonio ni nitritos entre reactores; las eficiencias medias de remoción fueron: amonio 4.78%, nitrito 27.2%, nitrato 32.3%, sólidos suspendidos 37.5%. Los reactores R4 y R5 presentaron mejor remoción de nitratos, con eficiencias medias de 47.4% y 42.8%. El R3 reportó la mejor remoción de SS con promedio del 58.2%. Conclusiones. El sistema de tratamiento del agua en el SRA garantizó condiciones de calidad del líquido, apropiadas para el cultivo de la trucha; el reactor más eficiente para la remoción de las formas de nitrógeno evaluadas fue el inoculado con lodos de la laguna aireada del RSA.

scholarly journals Performance Comparison of Fe2+ Activated Persulfate and Electro-Persulfate Process in Acid Blue 25 Removal from Aqueous Solution Operating: Conditions and Reaction Velocity

2020 ◽  
Author(s):  
Zeinab Ghorbani
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Ferrous Sulfate ◽  
Electrochemical Process ◽  
Sodium Persulfate ◽  
Sulfate Concentration ◽  
Reaction Velocity ◽  
Acid Blue 25 ◽  
Acid Blue ◽  
Activated Persulfate

The purpose of this study was to compare the performance of Fe2+ activated persulfate and electro-persulfate process in Acid Blue 25 removal from aqueous solution. For this reason, the effects of different parameters including pH, dye, sodium persulfate and ferrous sulfate concentrations were investigated. The removal efficiency of 92% at the time of 60 min was obtained at pH= 3, dye concentration= 50 mg/L, sodium persulfate concentration= 500 mg/L and Fe (II) sulfate concentration= 100 mg/L for Fe2+ activated persulfate system and the removal efficiency of 95% at pH= 5, dye concentration = 200 mg/L, sodium persulfate concentration = 500 mg/L and ferrous sulfate concentration = 100 mg/L for electro-persulfate system by means of graphite materials as the neutral electrodes. COD removal efficiency in Fe2+ activated persulfate and electro-persulfate in the mentioned conditions were 90% and 89% in 180 minutes, respectively. Moreover, the result of process kinetics showed that using electrochemical process improved the reaction velocity from 0.0016 to 0.0487 mg/L/min. The comparison between these two-process showed that using electrochemical process improved dye removal efficiency by 4 times.

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