scholarly journals Preparation of sludge-based hydrochar at different temperatures and adsorption of BPA

Author(s):  
Liyuan Chen ◽  
Dapeng Li ◽  
Yong Huang ◽  
Wenjuan Zhu ◽  
Yuqin Ding ◽  
...  

Abstract This study sought a new way to utilize sludge as a low cost and efficient adsorbent. Preparation of sludge adsorbent by hydrothermal carbonization was done at different temperatures (160–250 °C). Various characterization techniques were used in this study including elemental analysis, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The adsorption performance of the organic matter was analyzed by adsorption experiments with the endocrine disruptor bisphenol A (BPA). Results showed that as the hydrothermal temperature increased, the solid yield of hydrochar decreased from 84.73% to 55.19%, and the maximum specific surface area was 11.9 m2/g. Elemental analysis showed that the hydrochar contains more aromatic carbon than the raw sludge. It was found using the FT-IR and XPS that the hydrochar retains a large amount of oxygen-containing functional groups on the surface after hydrothermal treatment. Hydrochar can be used as an organic-pollutant adsorbent in water; it has a good adsorption effect on BPA and the removal rate can reach 96%. The adsorbed hydrochar can be hydrothermally retreated and returned to the sewage treatment plant for reuse.

2014 ◽  
Vol 926-930 ◽  
pp. 4353-4356
Author(s):  
Jing Zhao ◽  
Xiao Jun Xu ◽  
Qiang Zhan ◽  
Xuan Li ◽  
Shu Li Liu ◽  
...  

A lead-resistant strains was isolated from activated sludge of the sewage treatment plant in Chenggong County, Kunming, which was identified as Klebsiella by 16 SrDNA. The wet microbial cells were used as adsorbent, we studied adsorption properties for water Pb (II) ions in water of sorbent. The results showed that when the adsorbent treated the waste water with Pb (II) ions, the pH was 5, the time was 60min, the temperature was 30°C, the equilibrium adsorption amount was 73.45mg/g; Adsorbent’s adsorption of Pb (II) ions can better fit Langmuir isotherm model. The FT-IR result presented that the main component of adsorbent was polysaccharide, the physical adsorption and chemisorption occurred between the adsorbent and the Pb (II) ions in the solution, adsorption mainly involved with hydroxyl functional groups, the amide group and the carboxyl group, etc.


2014 ◽  
Vol 522-524 ◽  
pp. 854-860
Author(s):  
Qing Tao Zhang ◽  
Zhi Jian Zhang ◽  
Jiong Ma ◽  
Jiao Xiang

The growth performance of duckweed (Spirodela polyrrhiza) and its removal rate of nitrate and phosphorus in sewages taken from sewage treatment plant with different processes were studied. The experiments were conducted in an environmentally controlled growth chamber. Three kinds of sewages were taken from a grit chamber, a sedimentation tank, and the anoxic pond in a sewage treatment plant, respectively. The fourth kind of sewage was mixed using the sedimentation tank sewage and the anoxic pond sewage in a volumetric ratio 1:1. The weight of duckweed biomass were determined with a balance. Wastewater samples taken from the media were analyzed for total nitrogen (TN), ammonium nitrogen (NH4N), total phosphorus (TP), phosphatephosphorus (PO4P) using AA3 Continous Flow Analyzer. The results showed that Spirodela polyrrhiza grew well in sewages taken from grit chamber and sedimentation tank of a sewage treatment plant, whereas a lot of duckweed fronds were dead in the sewage taken from the anoxic pond due to the high TP (higher than 7.9 mg/L) and TN (higher than 51.6 mg/L). The suitable TN concentration for Spirodela polyrrhiza growth should not be higher than 45 mg/L. Compared with the treatments without duckweed, the NH4N concentrations were reduced more than 60% in ST and GC sewages with duckweed due to the NH4N uptake by duckweed. Spirodela polyrrhiza could remove TN efficiently in sewages with relative low concentration TN (less than 20 mg/L), while duckweed could not remove TN effectively in sewages with high concentration TN (higher than 20 mg/L). The TN concentration in GC sewage decreased greatly in the first four days, which probably brought about anaerobic condition, thus P uptake switched to net release of P, which caused the increase of the TP concentration in the GC sewage without duckweed in the last six days. O2 or oxidant should be provided for sewage treatment system using duckweed to ensure that efficient removal of TN and TP meanwhile. The TP and PO4P concentrations in the mixed sewage with duckweed increased far more than those for no-duckweed treatments, which could be related that the dead duckweed released P into the sewage.


2015 ◽  
Vol 737 ◽  
pp. 649-652
Author(s):  
Ming Li ◽  
Shuai Wang ◽  
De Chen Shan ◽  
Li Wei ◽  
Wen Jia Yin

In this study, IC anaerobic reactor was made to deal with the wastewater with high-concentration sulfate, the sludge from sewage treatment plant was put into two cells of IC reactor to domesticate sulfur-reducing bacteria (SRB), artificial water was made to simulate the wastewater with high-concentration SO42−. In order to remove the SO42− efficiently, two stages were designed in this study: sludge domestication stage and concentration strengthening stage. In sludge domestication stage, SRB could grow normally, the removal rate of SO42− was between 34.14% and 36.2%;in concentration strengthening stage, removal rate of SO42− was between 26% and 26.86%,demonstrating that SRB could grow and remove SO42− in such high-concentration SO42−( 38000 mg/L ) wastewater.


2013 ◽  
Vol 361-363 ◽  
pp. 601-605
Author(s):  
Ji Ku Zhang ◽  
Yang Yang Li ◽  
Chen Zhang ◽  
Yan Bin Yang

By treating the secondary effluent of Sanbaotun sewage treatment plant in Fushun with the CS type UV Sterilizer, the experiment researches the influence on the removal rate which includes the factors of turbidity, chromaticity, initial E.coli concentration of raw water, UV dose. The results show that the turbidity does not influence on UV disinfection efficiency with the turbidity from 1.5NTU to 3.8NTU. In the low-dose UV disinfection process, the influent sewage turbidity should under 4NTU to ensure the disinfection efficiency. Low chromaticity does not affect the UV disinfection efficiency, with the influent sewage chromaticity is under 15 degrees.The initial E. coli has a certain impact on little doses of UV disinfection with the concentration from 175 × 104 A/ L to 230 × 104 A/ L, no impact on high doses of UV disinfection。


2020 ◽  
Vol 145 ◽  
pp. 02052
Author(s):  
Weijian Zhou ◽  
Wenzhong Liang ◽  
Yining Ding ◽  
Yutao Lei ◽  
Zhihua Pang ◽  
...  

Considering the land shortage features of a given district in Hangzhou city, the High-sludge sedimentation tank + denitrification filtering tank + nitrification filtering tank + cloth media filtering tank process is adopted for purification treatment. When the system (with the treatment scale of 15,000m3/d) runs for 60 days, the average removal rate of COD and ammoniacal nitrogen are 86% and 96% respectively and the effluent quality reach the quasi grade IV standard.


2015 ◽  
Vol 737 ◽  
pp. 635-638
Author(s):  
Ke Zhao ◽  
Zheng Kong

The general existing low temperature problem in winter of north-city sewage treatment plant in the process of waste water treatment seriously affect the efficiency of the work. The research objective of this paper is to conduct investigate in the application of AICS method in Jilin Province, a sewage treatment plant engineering example has been employed to monitor the effluent of the indicators of sewage treatment under the low temperature condition during the winter the winter low temperature under the condition of sewage treatment plant effluent of the indicators; to understand the operation situation of sewage treatment plant, and to study the efficiency of hydrolysis - AICS processing waste-water. The result shows that: hydrolysis - AICS process works well in low temperature condition, the per TN removal rate is 76.79%, average removal rate of NH3 - N is 85.76%, average TP removal rate was 93.4%, the average COD removal rate was 90.6%. The effluent meet the national level A discharge standard requirements of "urban sewage treatment plant pollutant discharge standard". And through the retrenchment of the second pond and other ancillary equipment, Hydrolysis-AICS process could efficiently reduce the costs. Besides, the advantages of Hydrolysis-AICS process also include occupying small area, and operating easily and simply. Therefore Hydrolysis-AICS process is very helpful to achieve the sewage discharging standard in the northern towns.


Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 827 ◽  
Author(s):  
Yong Li ◽  
Siyuan Zhao ◽  
Jiejie Zhang ◽  
Yang He ◽  
Jianqiang Zhang ◽  
...  

The aerobic denitrifying phosphate accumulating bacteria (ADPB) use NO3− as an electron acceptor and remove nitrate by denitrification and concomitant uptake of excessive phosphorus in aerobic conditions. Activated sludge was collected from the A2O aerobic biological pool of the sewage treatment plant at Hezuo Town, Chengdu City. The candidate ADPB strains were obtained by cultivation in the enriched denitrification media, followed by repeated isolation and purification on bromothymol blue (BTB) solid plates. The obtained candidates were further screened for ADPB strains by phosphorus uptake experiment, nitrate reduction test, metachromatic granules staining, and poly-β-hydroxybutyrate (PHB) staining. The 16 sedimentation ribosome deoxyribonucleic acid (16 S rDNA) molecular technique was used to determine their taxonomy. Further, the denitrification and dephosphorization capacities of ADPB strains were ascertained through their growth characteristics in nitrogen-phosphorus-rich liquid media. The results revealed a total of 25 ADPB strains screened from the activated sludge of the A2O aerobic biological pool of the sewage treatment plant at Hezuo Town. These strains belonged to two classes, four orders, and five genera. Among them, the strain SW18NP2 was a potentially new species in the Acinetobacter genus, while the strain SW18NP24 was a potential new species in the Pseudomonas genus at the time of their characterization. The Acinetobacter was the dominant genus. The obtained ADPB strains demonstrated a rich diversity. The ADPB strains had significant variations in denitrification and dephosphorization capacities. Twenty-three strains exhibited a total phosphorus removal rate of above 50%, and 19 strains exhibited a total nitrogen removal rate of above 50%. The strain SW18NP2 showed the best denitrifying phosphorus removal (DPR) capacity, with a dephosphorization rate of 82.32% and a denitrification rate of 73.73%. The ADPB in the A2O aerobic biological pool of the sewage treatment plant at Hezuo Town demonstrated a rich diversity and a strong DPR capacity.


2013 ◽  
Vol 328 ◽  
pp. 297-303
Author(s):  
Si Mei Zhang ◽  
Lu Liu ◽  
Shu Heng Hu

Orbal oxidation ditch is widely used in urban sewage treatment system ,Oxygen consumption level is an important index to measure process operating characteristic, discuss the operation mode of Oxidation ditch under low dissolved oxygen concentration condition is the main link of Sewage plants energy saving operation. Through the adjustment of chongqing TongLiang sewage treatment plant Orbal oxidation ditch aerations equipment operation parameters, the operating power reduced 7.5 kW, the removal rate of TN increased from 19% to more than 50%,and COD, BOD5, TP, NH3 - N removal rate was not affected, the Water meet the design requirements.


2013 ◽  
Vol 409-410 ◽  
pp. 182-186
Author(s):  
Jun Yin ◽  
Jun Xiang Wang ◽  
Jia Ni Li ◽  
Jing Yi Cui

Based on the problem which is water quality instability and high energy consumption in the running of modified A2/O system in Changchun northern sewage treatment plant, we established the optimum parameters and optimized the operation conditions to provide technical support for the stable operation of the wastewater treatment plant by analyzing effect of the system in different conditions Test results showed the best dissolved oxygen concentration in the end of the aerobic tank, sludge recycling ratio and inner recycling ratio should be chosen 1.5~2.5mg/L, 80% and 180%. The operation results with optimal operation conditions showed that COD, ammonia nitrogen, SS, TN and TP removal rate were 89.07%, 80.44%, 95.27%, 61.09% and 89.88%. The process system effect is stable and effluent can satisfy the sewage discharged standards.


2018 ◽  
Vol 9 (2) ◽  
pp. 240-248 ◽  
Author(s):  
Zhilin Ran ◽  
Jia Zhu ◽  
Ke Li ◽  
Li Zhou ◽  
Pei Xiao ◽  
...  

Abstract The main component of surfactant is linear alkylbenzene sulfonate (LAS), which is toxic to the ecological environment and can cause serious harm. In this study, some activated sludge was taken from the aerobic and anaerobic tank of a sewage treatment plant in Shenzhen, then cultivated and domesticated in a membrane bioreactor with artificial surfactant wastewater. The start-up phase of the reactor adapted the constant-flux filtration, and the HRT was 12 h. The pH was below 5.5, which needed the addition of NaHCO3 after 6 days to adjust to the more optimal level (pH 6.5–7.5). After operation for 20 days, the start-up of the system was considered successful. At the early stage, the removal rates of chemical oxygen demand (COD) and LAS were relatively stable, reaching as high as 85.49%–93.31% and 80%, respectively. When the LAS concentration reached over 175 mg/L and the COD declined to about 83%, the removal rate of LAS also significantly decreased. LAS removal rate further decreased to about 60% when the dosage reached 200 mg/L, indicating that the resistance of microorganisms against LAS toxicity was also limited. LAS degradation could have been mainly driven by Dechloromonas, Gemmata, Pseudomonas and Zoogloea in the system.


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