Effect of Hydraulic Retention Time on Pretreatment of Sulfate-Laden Wastewater for Desulfurization-Denitrification Process

2010 ◽  
Vol 113-116 ◽  
pp. 536-539
Author(s):  
Wei Li ◽  
Xiao Liang ◽  
Jian Guo Lin
Keyword(s):  
Organic Carbon ◽  
Sulfate Reduction ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Reduction Stage ◽  
Sulfate Removal ◽  
Carbon Sulfide ◽  
Set Up ◽  
Denitrification Process

In order to treat wastewater rich in sulfate and organic carbon, an anaerobic attached-growth bioreactor was set up. It was the pretreatment of desulfurization-denitrification process. At hydraulic retention time of 128h-6.2h, sulfate removal rate and sulfide generating rate took on initial increasing and subsequent decreasing. At hydraulic retention time of 7.7h-10.2h, the removals of sulfate and organic carbon, sulfide generating rate reached 95.79%, 80% and 58.82%, respectively. The results showed that the suitable hydraulic retention time in sulfate reduction stage for the pretreatment of desulfurization-denitrification process was 7.7h-10.2h.

Effect of pH on Pretreatment of Sulfate-Laden Wastewater for Mixotrophic Desulfurization-Denitrification Process

2010 ◽  
Vol 113-116 ◽  
pp. 429-433
Author(s):  
Wei Li ◽  
Xiao Liang ◽  
Jian Guo Lin
Keyword(s):  
Organic Carbon ◽  
Ph Value ◽  
Removal Rate ◽  
Subsequent Treatment ◽  
Sulfate Removal ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Sulfurous Compounds ◽  
Set Up ◽  
Denitrification Process

An anaerobic attached-growth bioreactor was set up to treat wastewater rich in sulfate and organic carbon. It was the pretreatment of mixotrophic desulfurization-denitrification process. With pH decreasing from 8 to 7, the sulfate removal rate and oxidation reduction potential increased, while sulfide generating rate and effluent pH decreased. When pH value was maintained at 7.5, the removal rates of sulfate and organic carbon reached 91.5% and 90.5%, respectively. Meantime, the generating rate of sulfide reached 47.8%, which was beneficial to the subsequent treatment and to the thorough removal of sulfurous compounds. The results showed that the suitable influent pH in sulfate reduction stage for the pretreatment of desulfurization-denitrification process was 7.5.

Diverting electron fluxes towards sulfate reduction using linoleic acid in a mixed anaerobic culturePaper submitted to the Journal of Environmental Engineering and Science.

2010 ◽  
Vol 37 (11) ◽  
pp. 1492-1504
Author(s):  
Mamata Sharma ◽  
Nihar Biswas
Keyword(s):  
Linoleic Acid ◽  
Sulfate Reduction ◽  
Degradation Rate ◽  
Volatile Fatty Acids ◽  
Removal Rate ◽  
Electron Flow ◽  
Methane Formation ◽  
Sulfate Removal ◽  
Degradation Rates ◽  
High Concentrations

Sulfate (1500 mg/L) reduction and glucose (1870 mg/L) degradation was examined in the presence of five varying linoleic acid (LA) levels (100–1000 mg/L) at 37 ± 2 °C and pH 7.0–7.2. The sulfate reduction and methane formation data suggest that LA selectively inhibited methane producing bacteria (MPB). The quantity of sulfate removed increased with increasing LA dosage. Approximately 1375 mg/L (92%) sulfate was removed in cultures fed with high concentrations of LA (1000 mg/L), which was 68% more than that removed in glucose and sulfate controls. The quantity of sulfate removed in cultures fed with 100, 300, 500 and 700 mg/L LA were 62%, 66%, 77%, and 84%, respectively. Initial sulfate degradation rates increased with increasing LA levels in the cultures. High LA levels (1000 mg/L) attributed to approximately a sevenfold increase in the initial sulfate degradation rates compared to cultures containing sulfate plus glucose. The highest initial sulfate removal rate (0.19 µg/(mgVSS min)) was observed in cultures receiving 1000 mg/L LA. Initial glucose degradation rates decreased with increasing LA concentrations. The rates for the cultures receiving 1000 mg/L LA were 2.53 µg/(mgVSS min) while the degradation rate for cultures containing 100 mg/L LA was 5.40 µg/(mgVSS min). Methane formation decreased when sulfate and LA were added. Methane formation was lowest in cultures receiving elevated LA concentrations. The percent electron flow fluxes increased towards sulfidogenesis and decreased towards methanogenesis with increasing LA levels. Less than 0.6% electron flow was diverted to methanogenesis in cultures containing high levels of LA (≥700 mg/L) while ≤ 45% was diverted to sulfidogenesis. Acetate and propionate were the major volatile fatty acids (VFAs) detected during glucose degradation. The amount of sulfate reduced in the cultures receiving only LA or sulfate and no other carbon source was comparable (approximately 10%), which suggests that LA did not contribute to electrons during the course of experiment for sulfate reduction.

Research for Treating Avermectin Wastewater with UASB Technique

2011 ◽  
Vol 356-360 ◽  
pp. 1281-1284
Author(s):  
Yan Hong Chang ◽  
Hui Tao Feng ◽  
Hui Luo ◽  
San Jian Ma
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Nitrogen Concentration ◽  
Ammonia Nitrogen ◽  
Cod Removal ◽  
Stable Phase ◽  
Volume Load ◽  
Cod Removal Rate

The avermectin wastewater was treated with UASB technique. The paper was focused mainly on the removal rate of COD and the change of ammonia nitrogen of influent and effluent wastewater in the first running stage. At the stable phase of anaerobic operation, the removal rate of COD could be stabilized at 85% when the influent volume load was 9.21 kg/(m3•d), and the effluent COD was about 1400 mg/L. As for ammonia nitrogen concentration of influent and effluent wastewater, in the first 50 days, the former was larger than the latter, after then, it was opposite. In the condition of same volume load but different hydraulic retention time (COD concentration of influent being different), COD removal rate kept almost the same. In the second running stage, the influent COD volume load reached 9.21 kg/(m3•d) at the 16th day, with the COD removal rate being around 87%.

Two-Phase Mesophilic Anaerobic Co-Digestion of Food Waste and Sewage Sludge: Effect of Hydraulic Retention Time

2014 ◽  
Vol 852 ◽  
pp. 789-796 ◽  
Author(s):  
Guo Hua Wang ◽  
Lei Wang ◽  
Xue Jun Tan ◽  
Yi Xian Wang ◽  
Feng Wang
Keyword(s):  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Food Waste ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Two Phase ◽  
Acidogenic Reactor ◽  
In Series ◽  
The Impact

The impact of hydraulic retention time (HRT) on two-phase mesophilic (35°C) anaerobic co-digestion of food waste and sewage sludge was studied under mixing ratio of 1:1 on the TS basis. Laboratory-scale, two-phase anaerobic digestion systems were employed with each system consisting of an acidogenic reactor and a methanogenic reactor linked in series. For the acidogenic phase, an increase of volatile fatty acid (VFA) concentration was observed as HRT increased from 1d to 5d and the HRT of 5d was recommended for significantly higher VFA production and less propionate percentage, which could provide stable and favourable substrates for the methane reactor. Under acidogenic HRT of 5d, 20d was proved to be the optimum HRT for methanogenic phase with the methane content, methane production rate, methane yield and two-phase VS removal rate reached 71%, 0.7L/(L·d), 0.69L/gVSremoved and 64.7%, respectively. Results verified that the constraints of conventional anaerobic digestion for food waste or sewage sludge separately could be overcome by synergistic effect of co-digestion strategy and two-phase treatment.

scholarly journals Perencanaan Septic Tank Skala Rumah Tangga Untuk Penanganan Air Limbah

2018 ◽  
Vol 3 (2) ◽  
pp. 21-24
Author(s):  
Rudy Yoga Lesmana
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Cod Removal ◽  
Septic Tank ◽  
Cod Removal Rate ◽  
Bod Removal

Air limbah yang dihasilkan dari kegiatan rumah tangga jika tidak dikelola dengan baik maka akan menimbulkan masalah yang serius bagi lingkungan. Salah satu solusi dalam mengatasi permasalahan air limbah, yang ada di Indonesia yaitu dengan menggunakan septic tank. Septic tank umum digunakan di Indonesia karena menggunakan prinsip anaerob, yang hanya dibuat kemudian dibiarkan saja, tanpa perawatan yang rutin, dan jika ingin operasionalnya optimal maka perlu dikuras dengan jangka waktu 1 kali dalam setahun. Penelitian ini bertujuan untuk mengetaui Perkiraan kualitas dari effluent (BOD & COD) septic tank dan Berapa kapasitas volume dari septic tank untuk rumah tempat tinggal. Metode penelitian Besaran air limbah yang dihasilkan dari kegiatan rumah tangga menuju septic tank menurut Jayanudin (2016), adalah sebesar 120 L/hari atau 0,12 m3/hari dengan jumlah anggota keluarga ideal yaitu 5 orang. Dalam penelitian ini, air limbah mengalir selama 12 jam yang berasal dari kegiatan rumah tangga. Kadar COD yang dihasilakan Effluent pada septic tank ini adalah sebesar 207 mg/ltr dan COD Removal rate sebesar 31,5%, sedangkan Kadar BOD yang dihasilkan Effluent pada septic tank ini sebesar 411 mg/l dan BOD removal rate sebesar 31,5%. Untuk Akumulasi Volume lumpur yang dihasilkan selama 2 tahun (24 Bulan) adalah sebesar 0,081m3. Penurunan volume lumpur/sludge pada septic tank sebesar 68% atau Setelah 24 bulan volume lumpur menjadi 0,055 m3, semakin lama waktu penyimpanan lumpur di septic tank maka volumenya akan semakin berkurang. Volume septic tank yang dibutuhkan untuk menginapkan limbah selama 15 jam adalah sebesar 0,075, Semakin lama waktu Hydraulic retention time (HRT)/waktu tinggal limbah, maka akan semakin baik penguraian mikroorganisme dalam septic tank serta sebaliknya, semakin singkat waktu HRT maka proses penguraiannya samakin tidak baik.

scholarly journals Experimental study on treating agate dyeing wastewater with sulfate-reducing bacteria strengthening peanut shells and scrap iron

2017 ◽  
Vol 76 (4) ◽  
pp. 939-952
Author(s):  
Junzhen Di ◽  
Mingxin Wang
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Mesh Size ◽  
Sulfate Reducing Bacteria ◽  
Dyeing Wastewater ◽  
Sulfate Reducing ◽  
Peanut Shells ◽  
Scrap Iron ◽  
Reducing Bacteria

To solve the problems of high concentrations of Cr6+, SO42- and H+ in agate dyeing industrial wastewater and heavy pollution and high treating cost, single-factor and orthogonal experiments were conducted to determine the optimum particle size, the ratio of adsorbents dosing and hydraulic retention time based on peanut shells and scrap iron. Experiments, using five dynamic columns filled with the peanut shells, scrap iron and sulfate-reducing bacteria (SRB), were also conducted to determine the effect and mechanism of treating the wastewater. The results show that the best treatment effect was obtained when the diameter of peanut shells was 3 mesh, scrap iron being 60 mesh size, scrap iron and peanut shells with a ratio of 1:2, and hydraulic retention time being 24 h. By the comprehensive comparison of five groups of columns, the treating effect of column 4 was best, in which the removal rate of SO42- and Cr6+ was 30.17% and 88.36% respectively before adding the microorganisms, and 25.34% and 99.31% respectively after adding the microorganisms. The average of chemical oxygen demand (COD) release quantity was 62.11 and 513.75 mg·L−1, and the average effluent pH was 7.09 and 7.93 before and after addition of microorganisms respectively. In conclusion, peanut shells, scrap iron and SRB had a certain synergistic effect on treating agate dyeing wastewater.

Impact of the Hydraulic Retention Time on the Performance of a Sulfidogenic Bioreactor

2013 ◽  
Vol 825 ◽  
pp. 392-395 ◽  
Author(s):  
Robert Klein ◽  
Michael Schlömann ◽  
Yun Zeng ◽  
Bernd Wacker ◽  
Franz Glombitza ◽  
...  
Keyword(s):  
Microbial Community ◽  
Sulfate Reduction ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Reduction Process ◽  
Nucleotide Sequence Analysis ◽  
Rrna Gene ◽  
Mine Waters ◽  
Depth Analysis ◽  
Acidic Mine Water

Treatment of acidic Fe (II)- and sulfate-rich mine waters represents a major problem in many areas of the world. Therefore, a process was developed which utilises naturally occurring sulfate-reducing microorganisms for the elimination of sulfate and of part of the acidity from the acidic mine water. In order to improve the performance of this biological sulfate reduction process an in-depth analysis of the microbial diversity and activity in dependence of the hydraulic retention time (HRT) and other process parameters used to run the bioreactors was undertaken. This comparison demonstrated a positive correlation between shorter HRT and increasing sulfate reduction rates. The improvement in performance with decreasing HRT was paralleled by an increase of the total enzymatic activity (measured as hydrolase activity) of the microbial community and of the biomass (measured as protein concentration) in the bioreactors. A partial taxonomic identification of the microbial community in the bioreactors was achieved via nucleotide sequence analysis of a clone library of PCR-amplified 16S rRNA gene fragments prepared from a sample of the microbial biofilm in the bioreactor. Additionally, the genetic fingerprint technique T-RFLP was used to assess temporal changes of the microbial community in the biofilm within the reactor.

scholarly journals Simultaneous removal of Fe3+ and nitrate in the autotrophic denitrification immobilized systems

2017 ◽  
Vol 18 (5) ◽  
pp. 1625-1634
Author(s):  
Jun feng Su ◽  
Ting ting Lian ◽  
Ting lin Huang ◽  
Dong hui Liang ◽  
Wen dong Wang
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Nitrate Removal ◽  
Simultaneous Removal ◽  
Autotrophic Denitrification ◽  
Four Levels ◽  
Experimental Group

Abstract In this study, strain CC76, identified as Enterobacter sp., was tested for the reduction of Fe3+ and denitrification using immobilized pellets with strain CC76 as experimental group (IP) and immobilized pellets with strain CC76 and magnetite powder as experimental group (IPM) in the autotrophic denitrification immobilized systems (ADIS). Compared with IP, a higher nitrate removal rate was obtained with IPM by using three levels of influent Fe3+ (0, 5, and 10 mg/L), four levels of pH (5.0, 6.0, 7.0, and 8.0), and three levels of hydraulic retention time (HRT) (12, 14, and 16 h), respectively. Furthermore, response surface methodology (RSM) analysis demonstrated that the optimum removal ratios of nitrate of 87.21% (IP) and 96.27% (IPM) were observed under the following conditions: HRT of 12 h, pH of 7.0 and influent Fe3+ concentration of 5 mg/L (IP) and 1 mg/L (IPM).

Research on Performance Effected by HRT of PAC-MF Integrated Process

2010 ◽  
Vol 113-116 ◽  
pp. 1115-1118
Author(s):  
Cong Ma ◽  
Shui Li Yu ◽  
Li Wei ◽  
Lin Yan Zhang
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Membrane Separation ◽  
Removal Rate ◽  
Ammonia Nitrogen ◽  
High Dose ◽  
Hydraulic Residence Time ◽  
Water Treatment Process ◽  
Operation Conditions ◽  
Capital Construction

The hydraulic residence time (HRT) is a key parameter affecting the water treatment process, concerning water quality guarantee, short HRT will shrink capacity of structure, in order to reduce capital construction fee and operation cost. Filtration experiments using a bench-scale immersed membrane separation system combined with a high dose of PAC (powdered activated carbon) were conducted in order to investigate the effect for organic matters, pesticides and ammonia-nitrogen, and choose the optimal hydraulic retention time. The experiments were carried out under such operation conditions as a filtration rate of 0.5m/d, water temperature of 20°C. Synthetic water was used as the source water; the average influent concentrations of TOC (total organic carbon), and NH3-N (ammonia nitrogen) were 7.8mg/l, 6.8mg/l, respectively，201μg/L for THMFP and 201μg/L for Nitrobenzene. The results illustrated that, when HRT reduced from 3h to 1h, the removal rate of TOC, UV254 decreased a little, so did ammonia-nitrogen. But it had little effect on THMFP and nitrobenzene. When HRT was 1 hour, the average removal rate of TOC was 75%, 92% for ammonia-nitrogen, 97.5% for nitrobenzene and 75% for THMFP, which was all less than that of GB5749-2006 and that’s the optimal hydraulic retention time.

Study on Domestic Sewage Treatment with Rotating Biological Contactor

2012 ◽  
Vol 178-181 ◽  
pp. 376-379
Author(s):  
Fang Li ◽  
Zeng Lu Qi
Keyword(s):  
Removal Efficiency ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Domestic Sewage ◽  
Operating Parameters ◽  
Good Prospect ◽  
Rotating Biological Contactor

This paper adopted a 3-stage rotating biological contactor (RBC), while the operating parameters could be controlled properly, this kind of RBC can obtain better removal effect in domestic sewage treatment. At 25oC, when hydraulic retention time (HRT) is 4h ,6h,8h,10h and 12h ,removal rate of COD is 65.14%,86.10%,89.82%,85.93% and 78.58%.HRT fixes on 8h, removal rate of NH3 –N is 75% after adjusting alkalinity. When rotating rate of RBC is 4,6,8,10,12 and 14 r/min, the removal rate of TN is 53.88%,56.78%,60.03%,58.49%,55.32% and 54.87%.RBC also has a good removal efficiency of TP and obtains the removal rate of TP 45%.There is good prospect in domestic sewage treatment with RBC.

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