scholarly journals An investigation on treatment of tannery wastewater by electrocoagulation

2013 ◽  
Vol 11 (4) ◽  
pp. 546-555 ◽  
Keyword(s):  
Chemical Oxygen Demand ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Electrical Current ◽  
The Other ◽  
Tannery Wastewater ◽  
Contact Duration ◽  
A Value ◽  
Removal Efficiencies ◽  
Electro Coagulation

Treatability by the electro-coagulation (EC) and electro-Fenton (EF) methods have been applied to the tannery wastewater from an organized industrial region consisting mostly of tannery plants and compared with each other in this study. Iron plates were used as the anode and cathode. Electrical current was applied at a value of 33.3 mA m-2 for all processes in order to determine the electricity consumptions for chemical oxygen demand (COD) and sulfide removal. The optimal contact duration for each process was discovered at the end of the first five minutes. During the EC process, the removal efficiencies of COD and sulfide were 46% and 90%, respectively. Electricity consumptions were also obtained as 1.8 kWh kg- 1 COD removed and 27.7 kWh kg-1 sulfide removed. During the EF process, on the other hand, the removal efficiencies of COD and sulfide parameters were 54% and 85%, respectively, and electricity consumptions were also obtained as 1.5 kWh kg-1 COD removed and 8.3 kWh kg-1 sulfide removed. Furthermore, the removal efficiencies of total Chrome and suspended solids were determined to be 97% and 70%, respectively.

scholarly journals Taguchi Method and Response Surface Methodology in the Treatment of Highly Contaminated Tannery Wastewater Using Commercial Potassium Ferrate

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3784 ◽  
Author(s):  
Violetta Kozik ◽  
Krzysztof Barbusinski ◽  
Maciej Thomas ◽  
Agnieszka Sroda ◽  
Josef Jampilek ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Organic Carbon ◽  
Taguchi Method ◽  
Chemical Oxygen Demand ◽  
Total Organic Carbon ◽  
Response Surface ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Tannery Wastewater ◽  
Potassium Ferrate

The potential implementation of Envifer®, a commercial product containing potassium ferrate (40.1% K2FeO4), for the purification of highly contaminated tannery wastewater from leather dyeing processes was proposed. The employment of the Taguchi method for optimization of experiments allowed the discoloration (98.4%), chemical oxygen demand (77.2%), total organic carbon (75.7%), and suspended solids (96.9%) values to be lowered using 1.200 g/L K2FeO4 at pH 3 within 9 min. The application of the central composite design (CCD) and the response surface methodology (RSM) with the use of 1.400 g/L K2FeO4 at pH 4.5 diminished the discoloration, the chemical oxygen demand, the total organic carbon, and suspended solids within 9 min. The Taguchi method is suitable for the initial implementation, while the RSM is superior for the extended optimization of wastewater treatment processes.

Domestic wastewater treatment by a constructed wetland system planted with rice

2011 ◽  
Vol 64 (12) ◽  
pp. 2376-2380 ◽  
Author(s):  
Suwasa Kantawanichkul ◽  
Wanida Duangjaisak
Keyword(s):  
Wastewater Treatment ◽  
Chemical Oxygen Demand ◽  
Constructed Wetland ◽  
Retention Time ◽  
Paddy Field ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Biological Oxygen Demand ◽  
Removal Efficiencies

The experiments were conducted in four concrete laboratory scale free water surface constructed wetland units 1 m wide, 1.5 m long and 0.8 m deep. Paddy field soil was added to a depth of 0.4 m and rice seedlings (Oryza sativa L.) were transplanted into the units at a density of 25 plants/m2. Domestic wastewater collected from Chiang Mai University was applied into each unit via two different modes to evaluate suitable conditions for wastewater treatment and rice yield. In the first experiment, the wastewater was fed intermittently (7 h/day) with a hydraulic loading rate of 2, 4, 6 and 8 cm/day. The maximum removal efficiencies for chemical oxygen demand, biological oxygen demand, total kjedahl nitrogen and suspended solids were only 49.1, 58.7, 64.0 and 59.4%, respectively, due to the short hydraulic retention time for the biodegradation of organic substances. In the second experiment, the wastewater in each unit was inundated to a depth of 15 cm for 10, 15, 20 and 25 days in each unit and then drained and re-flooded. Removal efficiencies of chemical oxygen demand, biological oxygen demand, total kjedahl nitrogen and suspended solids were greater than in the first experiment especially at the 25 day retention time and except for suspended solids met the Thai national effluent standard. The study revealed that apart from wastewater treatment, wastewater can replace natural water to grow rice in the dry season or throughout the year. Moreover, nutrients in wastewater can be a substitute for chemical fertilizers. Rice grain production was 4,700 kg/ha and only 6% less than the production from the conventional paddy field.

Tannery wastewater pre-treatment

2009 ◽  
Vol 60 (2) ◽  
pp. 433-440 ◽  
Author(s):  
Mahmoud Abdel-Shafy Elsheikh
Keyword(s):  
Organic Matter ◽  
Biochemical Oxygen Demand ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Total Suspended Solids ◽  
Tannery Wastewater ◽  
Chemical System ◽  
Physico Chemical ◽  
Removal Efficiencies ◽  
Pre Treatment

Tannery wastewater is one of the most pollution sources. It can cause environmental problems related to its high organic matter, suspended solids and chromium. Chromium (III) salts are the most widely used chemicals for tanning processes, causing the tannery wastewater to be highly pollutant with chromium. The main objective of this study is to investigate the pre-treatment of an actual Egyptian tannery wastewater using two systems; the first electrolytic system and the second physico-chemical system. The performances of electrolytic system at current of 10, 20, 30 and 40 A were discussed. Poor removal efficiencies of chemical oxygen demand (COD), total suspended solids (TSS), chromium (III), ammonia (NH4+ and sulfide (S2−) were obtained. In the second physico-chemical system, calcium hydroxide was used as a coagulant material for chromium precipitation and plain sedimentation was applied for reducing of COD, biochemical oxygen demand (BOD5) and TSS. The results demonstrate 98.8% removal of chromium, 31% removal of COD, 25.8% removal of BOD5 and 51.2% removal of TSS.

Bamboo as an anaerobic medium: effect of filter column height

2001 ◽  
Vol 44 (4) ◽  
pp. 63-70 ◽  
Author(s):  
S. A.R. Camargo ◽  
E. A.A. Nour
Keyword(s):  
Chemical Oxygen Demand ◽  
Suspended Solids ◽  
Marked Decrease ◽  
Oxygen Demand ◽  
Total Suspended Solids ◽  
The Other ◽  
Column Height ◽  
Medium Effect ◽  
Operational Conditions ◽  
Anaerobic Medium

Sewage was treated in anaerobic filters filled with rings of bamboo (either whole or cut), and their effectiveness in the reduction of chemical oxygen demand (COD) was monitored along the entire extension of the filter. This efficiency was determined based on the COD reduction in both the brute effluent (COD-T) and that passed through a glass filter (COD-F). The quantity of total suspended solids (TSS) present at various heights in the filter column, measured at approximately 10-cm intervals from the false bottom to the height of the filter outflow (80 cm above) for various hydraulic detention times (HDT). The performance of the system resulted in little variation up to 5 hours of HDT, with the percentage of reduction of COD-T and COD-F being situated in the range of 60-80% and 40-80%, respectively. The first 40 cm of the filter proved to be relatively effective, and no significant differences in performance between whole and cut rings of bamboo were observed. A shock in pH occurring after 562 days of operation provoked an immediate and marked decrease in the performance of the reactors, especially that operating with a HDT of only 2 hours. This latter filter required more time to return to normal operational conditions than did the other reactors operating with longer HDT.

Comparison of Luffa Cylindrical Sponge and Plastic Sponge as Carriers in Sequencing Batch Biofilm Reactor for Sewage Treatment

2012 ◽  
Vol 518-523 ◽  
pp. 2431-2438
Author(s):  
Ying Zhang Wang ◽  
Shang Hua Zhang ◽  
Chang Qing Pang ◽  
Jie Li
Keyword(s):  
Chemical Oxygen Demand ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Suspended Solid ◽  
Biofilm Reactor ◽  
Environment Friendly ◽  
Sequencing Batch Biofilm Reactor ◽  
Removal Efficiencies

Luffa cylindrical sponge and plastic sponge were used as carriers in sequencing batch biofilm reactor (SBBR) for sewage treatment in this paper. The removals of suspended solid (SS), chemical oxygen demand (COD) and NH3-N in sewage were studied. The average removal efficiencies of SS, COD and NH3-N with luffa cylindrical sponge were 96%, 89% and 90%, respectively, while these with plastic sponge were 94%, 83% and 80%, respectively. As a natural, cheap and environment friendly biocarrier, luffa cylindrical sponge was easy to get a biofilm with enriched microbes during the first few days of sewage treatment. It was much more suitable as a carrier than the plastic sponge for SBBR.

scholarly journals Wastewater treatment in flow photobioreactors continuous illuminated by artificial and solar light

2020 ◽  
Vol 9 (6) ◽  
pp. e183963748
Author(s):  
Rafael Souza Leopoldino Nascimento ◽  
Ludymyla Marcelle Lima Silva ◽  
Lucas Periard ◽  
Anibal da Fonseca Santiago
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Chemical Oxygen Demand ◽  
Continuous Flow ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Total Suspended Solids ◽  
Operational Stability ◽  
Artificial Light ◽  
Light Emitting

The technology of microalgae photobioreactors and illuminated by LEDs has been widely studied for the treatment of wastewater. However, sunlight is a free resource and should be taken advantage of. But the question remains whether photobioreactors illuminated by natural (sunlight) light in combination with artificial light can have greater operational stability or greater performance when compared to systems illuminated only by artificial light. In this context, continuous flow photobioreactors illuminated by Light Emitting Diodes (LEDs) combined, or not, with sunlight were operated and had their performance evaluated. The variables analyzed were pH, OD, chemical oxygen demand (COD), chlorophyll - a and total suspended solids. The photobioreactors were effective for removing organic matter, with 75 ± 15% in the photobioreactor illuminated by LED and 65 ± 10% in the photobioreactor illuminated by sunlight and LED. The results showed that the use of combined lighting favors the production of dissolved oxygen and ensures greater operational stability in the removal of carbonaceous organic matter.

scholarly journals Performance comparison of uninsulated and insulated hybrid anaerobic baffled reactor (HABR) operating at warm temperature

2018 ◽  
Vol 78 (9) ◽  
pp. 1879-1892 ◽  
Author(s):  
Md Khalekuzzaman ◽  
Muhammed Alamgir ◽  
Mehedi Hasan ◽  
Md Nahid Hasan
Keyword(s):  
Removal Efficiency ◽  
Suspended Solids ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Total Suspended Solids ◽  
Performance Comparison ◽  
Warm Temperature ◽  
Anaerobic Baffled Reactor ◽  
Similar Chemical ◽  
Removal Efficiencies

Abstract In this research, a hybrid anaerobic baffled reactor (HABR) configuration was proposed consisting of a front sedimentation chamber and four regular baffled chambers followed by two floated filter media chambers for the treatment of domestic wastewater. Performance comparison of uninsulated and insulated HABRs was carried out operating at warm temperature (18.6–37.6 °C) under variable HRTs (30 h and 20 h). The study suggests that almost similar chemical oxygen demand (91% vs 88%), total suspended solids (90% vs 95%), turbidity (98% vs 97%), and volatile suspended solids (90% vs 93%) removal efficiencies were obtained for uninsulated and insulated HABRs. Higher removal of total nitrogen (TN) of 41%, NH4+-N of 44%, and NO3−-N of 91% were achieved by the insulated HABR compared to TN of 37%, NH4+-N of 36%, and NO3−-N of 84% by the uninsulated HABR, whereas lower PO43− removal efficiency of 17% was found in the insulated HABR compared to 24% in the uninsulated HABR. This indicated insulation increased nitrogen removal efficiencies by 4% for TN, 8% for NH4+-N and 7% for NO3−-N, but decreased PO43−removal efficiency by 7%.

Treatment of slaughterhouse plant wastewater by using a membrane bioreactor

2011 ◽  
Vol 64 (1) ◽  
pp. 214-219 ◽  
Author(s):  
Levent Gürel ◽  
Hanife Büyükgüngör
Keyword(s):  
Organic Carbon ◽  
Chemical Oxygen Demand ◽  
Membrane Bioreactor ◽  
Nitrate Nitrogen ◽  
Oxygen Demand ◽  
Organic Substances ◽  
Slaughterhouse Wastewater ◽  
Treated Effluent ◽  
Nitrogen Concentrations ◽  
Removal Efficiencies

The use of a membrane bioreactor (MBR) for removal of organic substances and nutrients from slaughterhouse plant wastewater was investigated. The chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) concentrations of slaughterhouse wastewater were found to be approximately 571 mg O2/L, 102.5 mg/L, and 16.25 mg PO4-P/L, respectively. A submerged type membrane was used in the bioreactor. The removal efficiencies for COD, total organic carbon (TOC), TP and TN were found to be 97, 96, 65, 44% respectively. The COD value of wastewater was decreased to 16 mg/L (COD discharge standard for slaughterhouse plant wastewaters is 160 mg/L). TOC was decreased to 9 mg/L (TOC discharge standard for slaughterhouse plant wastewaters is 20 mg/L). Ammonium, and nitrate nitrogen concentrations of treated effluent were 0.100 mg NH4-N/L, and 80.521 mg NO3-N/L, respectively. Slaughterhouse wastewater was successfully treated with the MBR process.

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