scholarly journals Removal of PAHs from leachate using a combination of chemical precipitation and Fenton and ozone oxidation

2018 ◽  
Vol 78 (5) ◽  
pp. 1064-1070 ◽  
Author(s):  
H. Ates ◽  
M. E. Argun
Keyword(s):  
Statistical Significance ◽  
Oxygen Demand ◽  
Chemical Precipitation ◽  
Operating Conditions ◽  
Program Optimization ◽  
Ozone Oxidation ◽  
Treatment Processes ◽  
Micropollutant Removal ◽  
Polycyclic Aromatic ◽  
Removal Efficiencies

Abstract In this study, six emerging pollutants, belonging to the polycyclic aromatic hydrocarbons (PAHs) group, found in landfill leachate were investigated for their removal by sequential treatment processes including chemical precipitation (CP), Fenton oxidation (FO) and ozone oxidation (OO). Each treatment process was run under different conditions using an experimental design program. Optimization of both CP and FO processes was designed based on the measured values of the residual chemical oxygen demand (COD) of the samples analyzed. The analysis of variance test was applied to the obtained results for determination of statistical significance of the model. Removal efficiencies of micropollutants were determined in the optimal conditions both for CP and FO processes. Samples obtained after these processes were treated with different pH and ozonation times for observing the performances of ozonation on micropollutant removal under different operating conditions. In this study, the removal of acenaphthylene, acenaphthene, fluorene, phenanthrene, fluoranthene and pyrene micropollutants was investigated. The values obtained for PAHs in leachate were determined to be above 10 ppb. In the CP process, the removal efficiencies for PAHs were ranged between 6% and 40% except for pyrene. Removal efficiencies of all micropollutants with FO were over 70% except for fluorene (55%). The removal efficiencies of the investigated micropollutants were 80–100% as a result of consecutive treatment processes including CP, FO and OO respectively.

Removal of pharmaceutical residue in municipal wastewater by DAF (dissolved air flotation)–MBR (membrane bioreactor) and ozone oxidation

2012 ◽  
Vol 66 (12) ◽  
pp. 2546-2555 ◽  
Author(s):  
Miyoung Choi ◽  
Dong Whan Choi ◽  
Jung Yeol Lee ◽  
Young Suk Kim ◽  
Bun Su Kim ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Ozone Oxidation ◽  
Dissolved Air Flotation ◽  
Treatment Processes ◽  
Pharmaceutical Residue ◽  
Dissolved Air

Growing attention is given to pharmaceutical residue in the water environment. It is known that pharmaceuticals are able to survive from a series of wastewater treatment processes. Concerns regarding pharmaceutical residues are attributed to the fact that they are being detected in water and sediment environment ubiquitously. Pharmaceutical treatment using a series of wastewater treatment processes of the DAF (dissolved air flotation)–MBR (membrane bioreactor)–ozone oxidation was conducted in the study. DAF, without addition of coagulant, could remove CODcr (chemical oxygen demand by Cr) up to over 70%, BOD 73%, SS 83%, T-N 55%, NH4+ 23%, and T-P 65% in influent of municipal wastewater. Average removal rates of water quality parameters by the DAF–MBR system were very high, e.g. CODcr 95.88%, BOD5 99.66%, CODmn (chemical oxygen demand by Mn) 93.63%, T-N 69.75%, NH4-N 98.46%, T-P 78.23%, and SS 99.51%, which satisfy effluent water quality standards. Despite the high removal rate of the wastewater treatment system, pharmaceuticals were eliminated to be about 50–99% by the MBR system, depending on specific pharmaceuticals. Ibuprofen was well removed by MBR system up to over 95%, while removal rate of bezafibrate ranged between 50 and 90%. With over 5 mg/l of ozone oxidation, most pharmaceuticals which survived the DAF–MBR process were removed completely or resulted in very low survival rate within the range of few micrograms per litre. However, some pharmaceuticals such as bezafibrate and naproxen tended to be resistant to ozone oxidation.

Optimization of leachate treatment using persulfate/H2O2 based advanced oxidation process: case study: Deir El-Balah Landfill Site, Gaza Strip, Palestine

2015 ◽  
Vol 73 (1) ◽  
pp. 102-112 ◽  
Author(s):  
Ahmed H. Hilles ◽  
Salem S. Abu Amr ◽  
Rim A. Hussein ◽  
Anwar I. Arafa ◽  
Olfat D. El-Sebaie
Keyword(s):  
Reaction Time ◽  
Advanced Oxidation Process ◽  
Gaza Strip ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Leachate Treatment ◽  
Operating Variables ◽  
Treatment Processes ◽  
N Removal

The objective of this study was to investigate the performance of employing H2O2 reagent in persulfate activation to treat stabilized landfill leachate. A central composite design (CCD) with response surface methodology (RSM) was applied to evaluate the relationships between operating variables, such as persulfate and H2O2 dosages, pH, and reaction time, to identify the optimum operating conditions. Quadratic models for the following two responses proved to be significant with very low probabilities (<0.0001): chemical oxygen demand (COD) and NH3-N removal. The obtained optimum conditions included a reaction time of 116 min, 4.97 g S2O82−, 7.29 g H2O2 dosage and pH 11. The experimental results were corresponding well with predicted models (COD and NH3-N removal rates of 81% and 83%, respectively). The results obtained in the stabilized leachate treatment were compared with those from other treatment processes, such as persulfate only and H2O2 only, to evaluate its effectiveness. The combined method (i.e., /S2O82−/H2O2) achieved higher removal efficiencies for COD and NH3-N compared with other studied applications.

scholarly journals Glucose Addition Enhanced the Advanced Treatment of Coking Wastewater

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3365
Author(s):  
Na Li ◽  
Yu Xia ◽  
Xuwen He ◽  
Weijia Li ◽  
Lianhua Yuan ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Oxygen Demand ◽  
Advanced Treatment ◽  
Secondary Effluent ◽  
Coking Wastewater ◽  
Glucose Addition ◽  
Refractory Organic Matter ◽  
Recalcitrant Compounds ◽  
Polycyclic Aromatic ◽  
Removal Efficiencies

Biological processes have high removal efficiencies and low operational costs, but the secondary effluent of coking wastewater (CWW), even at a low concentration, is difficult for microorganisms to degrade directly. In this study, glucose was used as a carbon source and co-metabolic substrate for microbial acclimation in order to enhance the advanced treatment of coking wastewater (CWW). The removal performance of the pollutants, especially recalcitrant compounds, was studied and the changes in the microbial community structure after activated sludge acclimation were analyzed. The effect of glucose addition on the secondary biochemical effluent of coking wastewater (SBECW) treatment by the acclimated sludge was further studied by a comparison between the performance of two parallel reactors seeded with the acclimated sludge. Our results showed that the concentrations of chemical oxygen demand (COD), total organic carbon (TOC), and UV absorption at 254 nm (UV254) of the wastewater decreased in the acclimation process. Refractory organic matter, such as polycyclic aromatic hydrocarbons and nitrogen-containing heterocyclics, in the SBECW was effectively degraded by the acclimated sludge. High-throughput sequencing revealed that microbes with a strong ability to degrade recalcitrant compounds were enriched after acclimation, such as Thauera (8.91%), Pseudomonas (3.35%), and Blastocatella (10.76%). Seeded with the acclimated sludge, the reactor with the glucose addition showed higher COD removal efficiencies than the control system without glucose addition (p < 0.05). Collectively, glucose addition enhanced the advanced treatment of coking wastewater (CWW).

scholarly journals Performance of Earthworm-Enhanced Horizontal Sub-Surface Flow Filter and Constructed Wetland

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1309 ◽  
Author(s):  
Rajendra Singh ◽  
Dafang Fu ◽  
Jing Jia ◽  
Jiaguo Wu
Keyword(s):  
Constructed Wetland ◽  
Low Impact Development ◽  
Oxygen Demand ◽  
Ammonium Nitrogen ◽  
Surface Flow ◽  
Water Levels ◽  
Operating Conditions ◽  
Experimental Conditions ◽  
Hydraulic Load ◽  
Removal Efficiencies

In this study, the performance of the horizontal sub-surface flow filter (HSSFF) and constructed wetland (HSSFCW) experimental units enhanced with earthworms was investigated for the treatment of construction camp sewage wastewater. All the experimental units (filter and constructed wetland) were filled with the same filler except Eisenia foetida earthworms and Lolium perenne Linn plants. The performance of the earthworm-enhanced filter (EEF) and the earthworm-enhanced constructed wetland (EECW) was compared to that of the blank filter (BF) units. The results revealed that the removal efficiencies for chemical oxygen demand (COD), ammonium-nitrogen (NH4+-N), total nitrogen (TN) and total phosphorus (TP) in EEF were higher than the BF unit. In order to optimize the operating conditions, the experiments were conducted in three different water levels. The results revealed that the removal efficiencies of EEF for these pollutants are the highest in experimental conditions no. 2 (water level ~30 cm; HRT ~3 days; hydraulic load ~4.05 cm/day; and Inflow discharge ~0.27 L/h). Compared to the EEF and BF units, the EECW has higher removal efficiency for COD and TN and has more stable performance than the filters. This work will aid the design and improvement of filters and CWs for treatment of effluent wastewater from construction camps. The selection of appropriate hydraulic parameters and experimental conditions could be very beneficial in achieving the goal of implantation of low impact development (LID).

Chlorinated Phenolics Removal from Bleached Kraft Mill Wastewater in Three Secondary Treatment Processes

1994 ◽  
Vol 29 (5-6) ◽  
pp. 177-187 ◽  
Author(s):  
E. R. Hall ◽  
W. G. Randle
Keyword(s):  
Activated Sludge ◽  
Treatment Process ◽  
Operating Conditions ◽  
Secondary Treatment ◽  
Threshold Values ◽  
Sludge Treatment ◽  
Treatment Processes ◽  
Kraft Mill Effluent ◽  
Kraft Mill ◽  
Removal Efficiencies

Laboratory-scale activated sludge (AS), facultative stabilization basin (FSB) and aerated stabilization basin (ASB) processes were operated in parallel treating bleached kraft mill effluent under controlled SRT and temperature conditions, to assess the chlorinated phenolics removal efficiencies attainable in each. The structure and extent of chlorination of the chlorophenolic compounds monitored appeared to contribute to the differing removal efficiencies observed. Under most operating conditions, treatment process effluents contained chronically toxic levels of pentachlorophenol-equivalent toxicity (TEQ). A companson of the results obtained from the FSB, ASB and AS processes indicated that, under most operating conditions, chlorophenolics removal in low rate treatment systems is superior to that in a higher rate activated sludge treatment process. However, it was also observed that operation at long SRT and moderate temperature permitted enhanced removal of chlorophenolics and reduced TEQs to less than threshold values, in all three treatment processes.

AOX Removal from Bleached Kraft Mill Wastewater: A Comparison of Three Biological Treatment Processes

1992 ◽  
Vol 26 (1-2) ◽  
pp. 387-396 ◽  
Author(s):  
E. R. Hall ◽  
W. G. Randle
Keyword(s):  
Biological Treatment ◽  
Operating Conditions ◽  
Gas Stripping ◽  
Treatment Processes ◽  
Organic Halogen ◽  
System Data ◽  
Kraft Mill ◽  
Removal Efficiencies ◽  
Comparison Of The Results ◽  
Aox Removal

Laboratory scale activated sludge (AS), facultative stabilization basin (FSB) and aerated stabilization basin (ASB) processes were operated under controlled parallel conditions to assess the AOX (adsorbable organic halogen) removal efficiencies attainable in each. A comparison of the results obtained under a variety of operating conditions indicated that higher removal efficiencies of total and filterable AOX were achieved in the FSB and ASB processes than in the AS system. Data are also presented to indicate the extent to which influent AOX was removed by biodegradation, biosorption and off-gas stripping.

scholarly journals Efficient removal of ammoniacal nitrogen from textile printing wastewater by electrooxidation considering the effects of NaCl and NaOCl addition

2021 ◽  
Author(s):  
Bengisu Cifcioglu-Gozuacik ◽  
Sinem Merve Ergenekon ◽  
Bahar Ozbey-Unal ◽  
Cigdem Balcik ◽  
Ahmet Karagunduz ◽  
...  
Keyword(s):  
Oxygen Demand ◽  
Operation Time ◽  
Operating Conditions ◽  
Ammoniacal Nitrogen ◽  
Efficient Removal ◽  
Applied Current ◽  
Solution Ph ◽  
Graphite Electrodes ◽  
Textile Printing ◽  
Removal Efficiencies

Abstract In this study, electrooxidation (EO) process using graphite electrodes as electrode pairs was used for the removal of chemical oxygen demand (COD), ammoniacal nitrogen (NH4+-N), and color from real textile printing wastewater. The effect of solution pH, sodium chloride (NaCl) dosage, sodium hypochlorite (NaOCl), which is the oldest and still most important chlorine-based bleach, dosage, and oxidation time were investigated on the removal efficiencies. Operating conditions of EO reactor were applied to current density 1 mA/cm2, distance between the electrodes: 2 cm, 150 min operation time, and stirring speed of 500 rpm. At optimum condition; pH 9.5, applied current desitiy 1 mA/cm2, NaCl dosage of 8 g/L, NaOCl dosage of 44.4 mg/L and 150 min electrooxidation time, the obtained removal efficiencies were 86.5% and 91.1% for COD and ammoniacal nitrogen, respectively. The efficiency was enhanced to 91.1% for ammoniacal nitrogen from 21.7% after applying EO combined with NaOCl addition compared to individual NaOCl addition.

DECOLOURIZATION AND COD REMOVAL OF WASEWATER FROM ETHANOL PRODUCTION PROCESS FROM MOLASSES BY COAGULANTION USING INORGANIC ALUM

2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le
Keyword(s):  
Ethanol Production ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Treatment Processes ◽  
Physico Chemical ◽  
Biological Methods ◽  
Treatment Step ◽  
Main Material

The industrial production of ethanol by fermentation using molasses as main material that generates large quantity of wastewater. This wastewater contains high levels of colour and chemical oxygen demand (COD), that may causes serious environmental pollution. Most available treatment processes in Vietnam rely on biological methods, which often fail to treat waste water up to discharge standard. As always, it was reported that quality of treated wastewater could not meet Vietnameses discharge standard. So, it is necessary to improve the treatment efficiency of whole technological process and therefore, supplemental physico-chemical treatment step before biodegradation stage should be the appropriate choice. This study was carried out to assess the effect of coagulation process on decolourization and COD removal in molasses-based ethanol production wastewater using inorganic coaglutant under laboratory conditions. The experimental results showed that the reductions of COD and colour with the utilization of Al2(SO4)3 at pH 9.5 were 83% and 70%, respectively. Mixture FeSO4 – Al2(SO4)3 at pH 8.5 reduced 82% of colour and 70% of COD. With the addition of Polyacrylamide (PAM), the reduction efficiencies of colour, COD and turbidity by FeSO4 – Al2(SO4)3 were 87%, 73.1% and 94.1% correspondingly. It was indicated that PAM significantly reduced the turbidity of wastewater, however it virtually did not increase the efficiencies of colour and COD reduction. Furthermore, the coagulation processes using PAM usually produces a mount of sludge which is hard to be deposited.

The Characteristics of Community Wastewater Biological Treatment Processes in Taiwan

1986 ◽  
Vol 18 (7-8) ◽  
pp. 289-296
Author(s):  
C. F. Ouyang ◽  
T. J. Wan
Keyword(s):  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Field Investigation ◽  
Oxidation Ditch ◽  
Trickling Filter ◽  
Rotating Biological Contactor ◽  
Treatment Processes ◽  
Treatment Characteristics ◽  
Sludge Thickening

This study investigated and compared the treatment characteristics of three different kinds of biological wastewater treatment plants (including rotating biological contactor, trickling filter and oxidation ditch) which are currently operated in Taiwan. The field investigation of this study concentrated on the following items: the performance of biological oxygen demand (BOD) and suspended solids (SS) removal; the sludge yield rate of BOD removal; the settleability of sludge solids; the properties of sludge thickening; the power consumption and land area requirement per unit volume of wastewater. Finally, based on the results of the field investigation, a comparison of the treatment characteristics of the three different biological treatment processes was evaluated.

Behaviour of Alkylphenol Polyethoxylate Surfactants and of Nitrilotriacetate in Sewage Treatment

1987 ◽  
Vol 19 (3-4) ◽  
pp. 449-460 ◽  
Author(s):  
W. Giger ◽  
M. Ahel ◽  
M. Koch ◽  
H. U. Laubscher ◽  
C. Schaffner ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Operating Conditions ◽  
Municipal Sewage ◽  
Sludge Treatment ◽  
Loading Rates ◽  
Treatment Conditions ◽  
Physico Chemical ◽  
Treated Sewage ◽  
Removal Efficiencies

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment. Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.

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