A study on ruthenium-based catalysts for pharmaceutical wastewater treatment

2011 ◽  
Vol 64 (1) ◽  
pp. 117-121 ◽  
Author(s):  
Y. J. Lei ◽  
X. B. Wang ◽  
C. Song ◽  
F. H. Li ◽  
X. R. Wang
Keyword(s):  
Fixed Bed ◽  
Oxygen Demand ◽  
Pyridine Derivatives ◽  
Catalytic Wet Oxidation ◽  
Pharmaceutical Wastewater ◽  
High Concentration ◽  
High Chemical ◽  
Organic Components ◽  
Fixed Bed Reactors ◽  
High Chemical Oxygen Demand

Ruthenium-based catalysts were prepared by a saturation-dip method. Their catalytic activity was evaluated by a catalytic wet oxidation (CWO) process. The ruthenium-based catalysts were used to purify organic pharmaceutical wastewater with high concentration pyridine and pyridine derivatives that have high chemical oxygen demand (COD). In the CWO process, organic pharmaceutical wastewater was continuously pumped into fixed-bed reactors filled with Ru-based catalysts, while the organic components in wastewater were catalytically degraded by oxygen at high temperatures and pressures (temperature, 170–300 °C; pressure, 1.0–10 MPa). The experimental results showed that the prepared catalysts could effectively purify pharmaceutical wastewater with high concentration organic components, which are difficult to degrade biochemically, and that the removal rates of both COD and total nitrogen were over 99%.

scholarly journals Catalytic wet oxidation of high concentration pharmaceutical wastewater with Fe3+ as catalyst

2018 ◽  
Vol 2017 (3) ◽  
pp. 661-666
Author(s):  
Xu Zeng ◽  
Jun Liu ◽  
Jianfu Zhao
Keyword(s):  
Oxygen Pressure ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Kinetic Studies ◽  
Cod Removal ◽  
Wet Oxidation ◽  
Catalytic Wet Oxidation ◽  
Pharmaceutical Wastewater ◽  
High Concentration ◽  
Temperature Time

Abstract Catalytic wet oxidation of high concentration pharmaceutical wastewater with Fe3+ as catalyst was carried out in a batch reactor. Results showed that the degradation of pharmaceutical wastewater was enhanced significantly by Fe3+. The effects of reaction parameters, such as the catalyst dose, reaction temperature, time, and initial oxygen pressure, were discussed. The chemical oxygen demand (COD) removal increased with the increases of catalyst dose, temperature, time and oxygen supply. With the initial COD 34,000–35,000 mg/L, approximately 70% COD removal can be achieved under the conditions of catalyst 1.0 g and oxygen pressure 1.0 MPa at 250 °C after 60 min. The results of kinetic studies showed that two reaction steps existed in this oxidation process, which followed an apparent first-order rate law. This process provides an effective approach for the pretreatment of high concentration pharmaceutical wastewater.

scholarly journals Treatment of landfill leachate with different techniques: an overview

2020 ◽  
Author(s):  
Amin Mojiri ◽  
John L. Zhou ◽  
Harsha Ratnaweera ◽  
Akiyoshi Ohashi ◽  
Noriatsu Ozaki ◽  
...  
Keyword(s):  
Landfill Leachate ◽  
High Performance ◽  
Membrane Filtration ◽  
Combined Treatment ◽  
Oxygen Demand ◽  
Ammonium Oxidation ◽  
High Chemical ◽  
Treatment Techniques ◽  
High Chemical Oxygen Demand ◽  
Biological Methods

Abstract Landfill leachate is characterised by high chemical and biological oxygen demand and generally consists of undesirable substances such as organic and inorganic contaminants. Landfill leachate may differ depending on the content and age of landfill contents, the degradation procedure, climate and hydrological conditions. We aimed to explain the characteristics of landfill leachate and define the practicality of using different techniques for treating landfill leachate. Different treatments comprising biological methods (e.g. bioreactors, bioremediation and phytoremediation) and physicochemical approaches (e.g. advanced oxidation processes, adsorption, coagulation/flocculation and membrane filtration) were investigated in this study. Membrane bioreactors and integrated biological techniques, including integrated anaerobic ammonium oxidation and nitrification/denitrification processes, have demonstrated high performance in ammonia and nitrogen elimination, with a removal effectiveness of more than 90%. Moreover, improved elimination efficiency for suspended solids and turbidity has been achieved by coagulation/flocculation techniques. In addition, improved elimination of metals can be attained by combining different treatment techniques, with a removal effectiveness of 40–100%. Furthermore, combined treatment techniques for treating landfill leachate, owing to its high chemical oxygen demand and concentrations of ammonia and low biodegradability, have been reported with good performance. However, further study is necessary to enhance treatment methods to achieve maximum removal efficiency.

Treatment of wine distillery wastewater by high rate anaerobic digestion

2007 ◽  
Vol 56 (2) ◽  
pp. 9-16 ◽  
Author(s):  
X.L. Melamane ◽  
R. Tandlich ◽  
J.E. Burgess
Keyword(s):  
Removal Efficiency ◽  
Biological Treatment ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
High Rate ◽  
High Chemical ◽  
Distillery Wastewater ◽  
The Mean ◽  
Removal Efficiencies ◽  
High Chemical Oxygen Demand

Wine distillery wastewaters (WDW) are acidic and have a high content of potential organic pollutants. This causes high chemical oxygen demand (COD) values. Polyphenols constitute a significant portion of this COD, and limit the efficiency of biological treatment of WDWs. WDW starting parameters were as follows: pH 3.83, 4,185 mg/l soluble COD (CODs) and 674.6 mg/l of phenols. During operation, amendments of CaCO3 and K2HPO4, individually or in combination, were required for buffering the digester. Volatile fatty acid concentrations were <300 mg/l throughout the study, indicating degradation of organic acids present. Mean CODs removal efficiency for the 130 day study was 87%, while the mean polyphenol, removal efficiency was 63%. Addition of 50 mg/l Fe3 +  between days 86 and 92 increased the removal efficiencies of CODs to 97% and of polyphenols to 65%. Addition of Co3 +  improved removal efficiencies to 97% for CODs and 92% for polyphenols. Optimization of anaerobic treatment was achieved at 30% WDW feed strength. Removal efficiencies of 92% and 84% were recorded at increased feed strength from days 108 to 130. High removal efficiencies of CODs and polyphenols after day 82 were attributed to the addition of macronutrients and micronutrients that caused pH stability and thus stimulated microbial activity.

scholarly journals Development of biofilm in anaerobic reactors treating wastewater from coffee grain processing

2010 ◽  
Vol 14 (2) ◽  
pp. 210-217 ◽  
Author(s):  
Fátima R. L. Fia ◽  
Alisson C. Borges ◽  
Antonio T. de Matos ◽  
Iolanda C. S. Duarte ◽  
Ronaldo Fia ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Fixed Bed ◽  
Oxygen Demand ◽  
Grain Processing ◽  
Anaerobic Reactors ◽  
Fixed Bed Reactors ◽  
Volatile Solids ◽  
High Pollution ◽  
Curved Rods ◽  
The Mean

In recent decades the use of anaerobic fixed bed reactors has been established in Brazil for the treatment of different effluents. As the capability of retaining microorganisms by support media (fixed bed) is a factor influencing the performance of these reactors, the present study aims at evaluating the influence of three fixed bed on the effectiveness of treating an effluent with high pollution potential: wastewater from coffee grain processing (WCP), with organic matter concentrations varying from 812 to 5320 mg L-1 in the form of chemical oxygen demand (COD). Support media used for the immobilization of biomass were: blast furnace slag, polyurethane foam and #2 crushed stone with porosities of 53, 95 and 48%, respectively. The mean efficiency of COD removal in the reactor filled with polyurethane foam was 80%, attributed to its higher porosity index, which also provided greater retention and fixation of biomass which, when quantified as total volatile solids, was found to be 1301 mg g-1 of foam. The biofilm was made up of various microorganisms, including rod, curved rods, cocci, filaments and morphologies similar to Methanosaeta sp. and Methanosarcina sp.

scholarly journals Opportunities and challenges for greywater treatment and reuse in Mongolia: lessons learnt from piloted systems

2014 ◽  
Vol 4 (3) ◽  
pp. 182-193 ◽  
Author(s):  
Sayed Mohammad Nazim Uddin ◽  
Zifu Li ◽  
Heinz-Peter Mang ◽  
André Schüßler ◽  
Tobias Ulbrich ◽  
...  
Keyword(s):  
Suspended Solids ◽  
Oxygen Demand ◽  
National Standards ◽  
Who Guidelines ◽  
High Chemical ◽  
Treatment Unit ◽  
User Training ◽  
Environment And Health ◽  
Business Opportunities ◽  
High Chemical Oxygen Demand

In Mongolia, as worldwide, communities are challenged by water scarcity, depletion and pollution. Greywater treatment and reuse could partially meet water demand and help protect the environment and health. In March 2010, greywater from six randomly sampled households in the Ger areas of Ulaanbaatar, Mongolia, was analyzed followed by the development of three innovative treatment systems: an underground (UG-), greenhouse (GH-) and ice-hole greywater treatment unit (IH-GWTU). The UG- and GH-GWTU were implemented to identify opportunities and challenges for future investments in greywater treatment and reuse. Users' and non-users' perceptions, and business opportunities, were assessed. Laboratory analysis showed a high chemical oxygen demand (6,072–12,144 mg/l), N-NH4+ (183.7–322.6 mg/l), PO4− (12.6–88.2 mg/l) and total suspended solids (880–3,200 mg/l) – values exceeding the WHO guidelines and much higher than in any other country: low water consumption combined with traditional diet might be major reasons. Odourless and colourless water after treatment in a UG-GWTU lead to more acceptance than a GH-GWTU. Business opportunities include the use of treated water for irrigation, considering WHO and national standards. Further research focuses on seasonality of installation, technical shortcomings, maintenance, biological quality control and user training.

Study on Coking Wastewater Treatment by Fixed Bed of Metallization Pellets with High Carbon

2011 ◽  
Vol 356-360 ◽  
pp. 1942-1946 ◽  
Author(s):  
Wu Feng Jiang ◽  
Su Ju Hao ◽  
Yun Han Ling
Keyword(s):  
Wastewater Treatment ◽  
Degradation Rate ◽  
Fixed Bed ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Coking Wastewater ◽  
High Carbon ◽  
Fixed Bed Reactors ◽  
Ft Ir ◽  
Degradation Effect

Coking wastewater produced in the coking process is poisonous and difficult to be degraded. Coking wastewater was treated by fixed bed reactors of metallization pellets with high carbon (MPHC). In this paper, it studies the effect of removing phenols, cyanide, chemical oxygen demand（COD）and ammonia nitrogen in coking wastewater by MPHC. The results show that MPHC has good degradation effect on phenols and cyanide in coking wastewater, and the degradation rate reaches to 99.88% and 99.81% respectively; and has certain degradation effect on COD, the degradation rate is 70.61%; has poor degradation effect on ammonia nitrogen. The results of FT-IR indicate that the degradation of organic pollutants in coking wastewater by MPHC is not simply adsorption, but is removed completely.

scholarly journals Physico-chemical Characterization of the Leachate from Fermentation Composts Treated with Lime and Soda: Case of the Composting Platform in Aného, Togo

2021 ◽  
pp. 117-126
Author(s):  
Edem K. Kolédzi ◽  
Nitale M’Balikine Krou ◽  
Kwamivi N. Ségbéaya ◽  
E. Aziablé
Keyword(s):  
Suspended Matter ◽  
Reduction Rate ◽  
Oxygen Demand ◽  
Chemical Characterization ◽  
Household Waste ◽  
Good Reduction ◽  
High Chemical ◽  
Physico Chemical ◽  
High Chemical Oxygen Demand

This study aims to determine the parameters measuring the reduction rate of the organic matter during fermentation and its bio-availability after maturation of the compost made using fermentable fractions of household waste. Thus, a physico-chemical characterization of the raw leachate and the leachate treated with lime and caustic soda was carried out. The results showed that, the contents of the other parameters measured are higher for the raw leachate compared to those obtained for the treated leachate. Organic and inorganic pollution is reflected by high Chemical Oxygen Demand (COD), absorbance at 254 nm, turbidity and suspended matter. The COD values ​​in the raw leachate vary between 13000 and 19150 mg/O2/L; those of the absorbance at 254 nm between 30.5 and 34.15 OD; those of turbidity between 156 and 255 NTU (Nephelometric Turbidity Unit) and those of suspended matter between 48 and 1600 mg/L. In the treated leachate, the COD values ​​oscillate between 4489 and 8743 mg/O2/L; those of the absorbance at 254 nm between 6.69 and 31.1 OD; those of turbidity between 57.8 and 122 NTU and those of suspended matter between 70 and 92 mg. These results reflect a good reduction after treatment with lime and soda.

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