Enhanced treatment of tannery wastewater in an integrated multistage bioreactor (IMBR) by the predominant bacterial strains enriched from marine sediments

2015 ◽  
Vol 73 (4) ◽  
pp. 807-817
Author(s):  
Guangdao Huang ◽  
Guofeng Fan ◽  
Guoguang Liu

An innovative integrated multistage bioreactor (IMBR) system, which was augmented with three predominant bacterial strains (Lactobacillus paracasei CL1107, Pichia jadinii CL1705, and Serratia marcescens CL1502) isolated from marine sediments, was developed to treat real tannery wastewater without performing physicochemical pretreatment, with the potential to reduce the generation of waste sludge and odors. The performance of the IMBR treatment system, with and without the inclusion of the predominant bacterial strains, was compared. The results indicated that the performance of the IMBR system without bioaugmentation by the predominant bacterial strains was poor. However, when in the presence of the predominant bacterial strains, the IMBR system exhibited high removal efficiencies of chemical oxygen demand (COD) (97%), NH4+-N (97.7%), and total nitrogen (TN) (90%). In addition, the system had the capacity for the simultaneous removal of organics and nitrogen, heterotrophic nitrification and denitrification being carried out concurrently, thereby avoiding the strong inhibition of high concentrations of COD on nitrification. The system possessed excellent adaptability and ability to resist influent loading fluctuations, and had a good alkalinity balance such that it could achieve a high NH4+-N, and TN removal efficiency without a supplement of external alkalinity. In addition, an empirical performance modeling of the IMBR system was analyzed.

2013 ◽  
Vol 11 (4) ◽  
pp. 546-555 ◽  

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.


2021 ◽  
Author(s):  
Hui Liu ◽  
Junyu Liang ◽  
Giorgos Markou ◽  
Zhaofeng Song ◽  
Jianfeng Ye

Abstract Swine wastewater (SW) poses a great threat to the environment due to its high-nutrient profiles if not properly managed. Advanced biological treatment method is an efficient method to treat SW by screening potent microalgae or bacterial strains. In this study, activated sludge, nine locally isolated heterotrophic nitrification bacteria and one microalgal strain (Chlorella) were used as inoculums in treating a local SW. Their treatment efficiencies were compared, while the nitrogen removal mechanisms and microbiome profile were explored in detail. It was found that certain heterotrophic nitrification strains had a slight advantage in removing chemical oxygen demand and phosphorus from SW, with the highest removal efficiencies of 83.9% and 76.2%, respectively. The removal efficiencies of ammonia nitrogen and total nitrogen in wastewater by microalgae reached 80.9% and 66.0% respectively, which were far higher than all the heterotrophic nitrification strains. Biological assimilation was the main pathway of nitrogen conversion by microalgae and heterotrophic nitrifying bacteria; especially microalgae showed excellent biological assimilation performance. Correlation analysis showed that Comamonas was highly positively correlated with nitrogen assimilation, while Acidovorax was closely correlated with simultaneous nitrification and denitrification. This study gives a comparison of microalgae and heterotrophic nitrifying bacteria on the nitrogen transfer and transformation pathways.


2009 ◽  
Vol 60 (2) ◽  
pp. 433-440 ◽  
Author(s):  
Mahmoud Abdel-Shafy Elsheikh

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.


2021 ◽  
Vol 14 ◽  
pp. 117862212110281
Author(s):  
Ahmed S. Mahmoud ◽  
Nouran Y. Mohamed ◽  
Mohamed K. Mostafa ◽  
Mohamed S. Mahmoud

Tannery industrial effluent is one of the most difficult wastewater types since it contains a huge concentration of organic, oil, and chrome (Cr). This study successfully prepared and applied bimetallic Fe/Cu nanoparticles (Fe/Cu NPs) for chrome removal. In the beginning, the Fe/Cu NPs was equilibrated by pure aqueous chrome solution at different operating conditions (lab scale), then the nanomaterial was applied in semi full scale. The operating conditions indicated that Fe/Cu NPs was able to adsorb 68% and 33% of Cr for initial concentrations of 1 and 9 mg/L, respectively. The removal occurred at pH 3 using 0.6 g/L Fe/Cu dose, stirring rate 200 r/min, contact time 20 min, and constant temperature 20 ± 2ºC. Adsorption isotherm proved that the Khan model is the most appropriate model for Cr removal using Fe/Cu NPs with the minimum error sum of 0.199. According to khan, the maximum uptakes was 20.5 mg/g Cr. Kinetic results proved that Pseudo Second Order mechanism with the least possible error of 0.098 indicated that the adsorption mechanism is chemisorption. Response surface methodology (RSM) equation was developed with a significant p-value = 0 to label the relations between Cr removal and different experimental parameters. Artificial neural networks (ANNs) were performed with a structure of 5-4-1 and the achieved results indicated that the effect of the dose is the most dominated variable for Cr removal. Application of Fe/Cu NPs in real tannery wastewater showed its ability to degrade and disinfect organic and biological contaminants in addition to chrome adsorption. The reduction in chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS), total phosphorus (TP), total nitrogen (TN), Cr, hydrogen sulfide (H2S), and oil reached 61.5%, 49.5%, 44.8%, 100%, 38.9%, 96.3%, 88.7%, and 29.4%, respectively.


Author(s):  
Ahmad Zuhairi Abdullah ◽  
Mohamad Hakimi Ibrahim ◽  
Mohd. Omar Ab. Kadir

Kertas kerja ini membincangkan tentang kecekapan penuras cucur dalam merawat supernatan kumbahan kilang kelapa sawit (POME). Supernatan POME diperoleh menerusi dua jenis perawatan. Dalam perawatan 1, pengendapan graviti digunakan untuk menyingkir pepejal boleh mendak. Perawatan 2 digunakan untuk menyingkir pepejal boleh mendak dan gumpalan partikal dengan menggunakan 350 ppm alum. Influen dialurkan secara titisan pada biojisim yang terlekat pada penyokong pepejal rawak PVC setinggi 1 m. Penuras cucur berupaya menyingkir lebih daripada 90.0% dari keperluan oksigen biologi (BOD) dan keperluan oksigen kimia (COD) di bawah 1 m3/m2–hari. Pada 2.53 m3/m2–hari, influen dengan Perawatan 1 menghasilkan kecekapan penyingkiran COD sebanyak 40.3%, berbanding 83.1% bila Perawatan 2 digunakan. Perkara ini berlaku berikutan penyingkiran bahan organik tak boleh resap semasa Perawatan 2. Kecekapan penyingkiran menurun dengan meningkatnya bebanan hidraulik kerana wujudnya kelemahan dalam hidrolisis bahan tak boleh resap kepada substratum larut. Dengan edaran semula (α=1), penyingkiran BOD dan COD yang lebih tinggi dicapai di bawah 7 m3/m2–hari. Pencapaian ini disebabkan oleh bebanan organik yang lebih rendah serta pergedaran semula enzim dan biojisim yang aktif kepada sistem. Perawatan 2 menghasilkan enap cemar yang lebih tinggi kerana penukaran substratum boleh larut kepada biojisim tak boleh larut. Hidrolisis bahan organik tak boleh resap didapati berlaku secara aktif pada bahagian atas penuras cucur sementara bahagian bawahnya cenderung mengoksidakan substratum organik. Kata kunci: POME, turas cucur, bahan organik bolehresap, penggumpalan, alir semula This paper discusses the efficiency of a trickling filter to treat Palm Oil Mill Effluent (POME) supernatants. POME supernatants were obtained via two treatments. In Treatment 1, gravity sedimentation was used to remove settleable solids. In Treatment 2, both settleable solids and colloidal particles were removed using 350 ppm of alum. The influents were allowed to trickle over biomass attached to 1 m high random PVC solid support. Below 1 m3/m2–day, the filter demonstrated Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) removal efficiencies of more than 90.0%. At 2.53 m3/m2–day, the influent with Treatment 1 gave a COD removal efficiency of 40.3%, but increased to 83.1% when the influent with Treatment 2 was used. This was ascribed to the removal of non–diffusible organics during Treatment 2. The removal efficiencies decreased with an increase in hydraulic loading due to limitations in the hydrolysis of non–diffusibles into soluble substrates. With recirculation (α=1), higher BOD and COD removals were achieved below 7.0 m3/m2–day, attributed to lower organic loading and the recycling of active enzyme and biomass to the system. The influent with Treatment 2 demonstrated higher sludge production due to higher conversion of soluble substrates into insoluble biomass. Hydrolysis of non–diffusible organics mainly took place at upper reaches of the filter column while lower reaches were involved in oxidizing the organic subtrates. Key words: POME, trickling filter, diffusible organic, coagulation, recirculation


2014 ◽  
Vol 665 ◽  
pp. 487-490
Author(s):  
Te Wang ◽  
Zhao Xia Liu ◽  
Mei Juan Wu ◽  
Fu Hui Kang ◽  
Qing Chen ◽  
...  

A bacterium capable of simultaneous heterotrophic nitrification and aerobic denitrification at high concentrations of ammonia-nitrogen was screened and identified and the denitrification property was investigated in this paper. The strain was isolated from aeration tank of wastewater disposed by activated sludge and analyzed and identified by 16S rDNA. The effects of different carbon sources and carbon and nitrogen mass ratios on denitrification rate were studied. The changes of various forms of ammonia-nitrogens during the simultaneous heterotrophic nitrification and aerobic denitrification process were characterized. A strain capable of simultaneous heterotrophic nitrification and aerobic denitrification at 600 mg/L nitrogen concentration has been isolated and screened. Comparison of its 16S rDNA sequence showed 100% similarity to Bacillus licheniformis strain Lr124/6. The strain was named as Bacillus sp. A22. The optimal conditions for degradation of ammonia-nitrogen by Bacillus sp. A22 were trisodium citrate as carbon source and carbon and nitrogen mass ratios of 10. The denitrification rate was 98.2% after 96 h of culture under the optimal conditions and there was hardly any intermediates accumulation in the denitrification process. It has practical applications that the denitrification can be performed efficiently at high concentrations of ammonia-nitrogen by method of simultaneous heterotrophic nitrification and aerobic denitrification by Bacillus sp. A22 in nitrogen purification treatment of wastewater with high concentrations of ammonia-nitrogen.


2017 ◽  
Vol 77 (4) ◽  
pp. 988-998 ◽  
Author(s):  
Tadesse Alemu ◽  
Andualem Mekonnen ◽  
Seyoum Leta

Abstract In the present study, a pilot scale horizontal subsurface flow constructed wetland (CW) system planted with Phragmites karka; longitudinal profile was studied. The wetland was fed with tannery wastewater, pretreated in a two-stage anaerobic digester followed by a sequence batch reactor. Samples from each CW were taken and analyzed using standard methods. The removal efficiency of the CW system in terms of biological oxygen demand (BOD), chemical oxygen demand (COD), Cr and total coliforms were 91.3%, 90%, 97.3% and 99%, respectively. The removal efficiency for TN, NO3− and NH4+-N were 77.7%, 66.3% and 67.7%, respectively. Similarly, the removal efficiency of SO42−, S2− and total suspended solids (TSS) were 71.8%, 88.7% and 81.2%, respectively. The concentration of COD, BOD, TN, NO3−N, NH4+-N, SO42 and S2− in the final treated effluent were 113.2 ± 52, 56 ± 18, 49.3 ± 13, 22.75 ± 20, 17.1 ± 6.75, 88 ± 120 and 0.4 ± 0.44 mg/L, respectively. Pollutants removal was decreased in the first 12 m and increased along the CW cells. P. karka development in the first cell of CW was poor, small in size and experiencing chlorosis, but clogging was higher in this area due to high organic matter settling, causing a partial surface flow. The performance of the pilot CW as a tertiary treatment showed that the effluent meets the permissible discharge standards.


2008 ◽  
Vol 71 (1) ◽  
pp. 205-209 ◽  
Author(s):  
SILVIA BONETTA ◽  
SARA BONETTA ◽  
ELISABETTA CARRARO ◽  
JEAN DANIEL COÏSSON ◽  
FABIANO TRAVAGLIA ◽  
...  

The aim of this study was to research decarboxylating bacterial strains and biogenic amine content in a typical Italian goat cheese (Robiola di Roccaverano). The study was performed on fresh and ripened samples of goat cheese manufactured from industrial and artisanal producers. Sixty-seven bacterial strains isolated showed decarboxylating activity, and Enterococcus faecalis was the most widespread decarboxylating species in all artisanal and industrial products. Pediococcus acidilactici and Enterococcus malodoratus were also identified as biogenic amine producers in Robiola di Roccaverano cheese. All the E. faecalis strains isolated in this study were able to decarboxylate tyrosine. Tyramine was the most abundant biogenic amine in cheese samples, while histamine was the most widespread. High amounts of these two biogenic amines were found in ripened samples (up to 2,067 mg/kg for tyramine and 1,786 mg/kg for histamine), whereas 2-phenylethylamine and tryptamine were present in almost all ripened cheeses at low concentrations. The detection of strains producing biogenic amines and the high concentrations of tyramine and histamine found in ripened Robiola di Roccaverano could represent a potential risk to the consumer.


2006 ◽  
Vol 54 (11-12) ◽  
pp. 155-164 ◽  
Author(s):  
T. Koottatep ◽  
C. Polprasert ◽  
S. Hadsoi

Faecal sludge (FS) from the on-site sanitation systems is a nutrient-rich source but can contain high concentrations of toxic metals and chemicals and infectious micro-organisms. The study employed 3 vertical-flow CW units, each with a dimension of 5×5×0.65 m (width×length×media depth) and planted with cattails (Typha augustifolia). At the solid loading rate of 250 kg total solids (TS)/m2.yr and a 6-day percolate impoundment, the CW system could achieve chemical oxygen demand (COD), TS and total Kjeldahl nitrogen (TKN) removal efficiencies in the range of 80–96%. A solid layer of about 80 cm was found accumulated on the CW bed surface after operating the CW units for 7 years, but no clogging problem has been observed. The CW percolate was applied to 16 irrigation sunflower plant (Helianthus annuus) plots, each with a dimension of 4.5×4.5 m (width×length). In the study, tap water was mixed with 20%, 80% and 100% of the CW percolate at the application rate of 7.5 mm/day. Based on a 1-year data in which 3 crops of plantation were experimented, the contents of Zn, Mn and Cu in soil of the experimental plots were found to increase with increase in CW percolate ratios. In a plot with 100% of CW percolate irrigation, the maximum Zn, Mn and Cu concentrations of 5.0, 12.3 and 2.5 mg/kg, respectively, were detected in the percolate-fed soil, whereas no accumulation of heavy metals in the plant tissues (i.e. leaves, stems and flowers) of the sunflower were detected. The highest plant biomass yield and oil content of 1000 kg/ha and 35%, respectively, were obtained from the plots fed with 20% or 50% of the CW percolate.


2004 ◽  
Vol 49 (5-6) ◽  
pp. 281-288 ◽  
Author(s):  
S.J. Kim ◽  
P.Y. Yang

A two-stage entrapped mixed microbial cell (2SEMMC) process which separates nitrification and denitrification phases by the installation of the anoxic and oxic EMMC reactors packed with EMMC carriers was operated with 6, 4, 3, and 2 hours of hydraulic retention time (HRT) using simulated domestic wastewater. The activated sludge was immobilized using cellulose acetate for the EMMC carriers. Similar soluble chemical oxygen demand (SCOD) removal efficiencies of 90-97% were observed for all HRTs (SCOD loading rate of 0.84-2.30 g/L/d) applied. In order to achieve more than 80 % of TN removal efficiency, the HRT should be maintained higher than 4 hours (less than 0.24 g/L/d of TN loading rate). Denitrification was a rate-limiting step which controlled overall TN removal efficiency at TN loading rate of 0.15-0.31 g/L/d although nitrification efficiencies achieved 97-99 %. The effluent TSS of less than 25 mg/L in the 2SEMMC process was maintained at the SCOD loading rate of less than 1.23 g/L/d with back-washing intervals of 5 and 10 days in the anoxic and oxic EMMC reactors, respectively. The minimum HRT of 4 hours is required for high removal efficiencies of organics (average 95.6 %) and nitrogen (average 80.5 %) in the 2SEMMC process with 3 times of recirculation ratio.


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