scholarly journals Experimental Investigation of Sludge Treatment Using a Rotor-Stator Type Hydrodynamic Cavitation Reactor and an Ultrasonic Bath

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 790 ◽  
Author(s):  
Hyunsoo Kim ◽  
Xun Sun ◽  
Bonchan Koo ◽  
Joon Yong Yoon
Keyword(s):  
Chemical Oxygen Demand ◽  
Reduction Rate ◽  
Oxygen Demand ◽  
Hydrodynamic Cavitation ◽  
Volume Index ◽  
Treatment Technique ◽  
Cross Sectional ◽  
Sludge Treatment ◽  
Ultrasonic Bath ◽  
Oxidation Performance

In the present work, the sludge treatment performance of a sludge treatment using a rotor-stator type hydrodynamic cavitation reactor (HCR) was investigated. To verify the performance, a comparison with an ultrasonic bath was conducted in four experimental cases using three assessment factors. The HCR consisted of a rotor and three covers with inserted dimples resulting in variation of the cross-sectional area in a flow. The experimental cases were established using the same energy consumption for each device. Disintegration performance was analyzed with assessment factors using particle size distribution and sludge volume index (SVI), oxidation performance using total chemical oxygen demand (TCOD) and volatile suspended solids (VSS) reduction rate, as well as solubilization rate using soluble chemical oxygen demand (SCOD). As a result, the particle disintegration and oxidation performance of the HCR were generally superior to those of the ultrasonic bath. However, due to the contradictory interactions of these factors, the solubilization rate of the two devices was measured similarly as 42.3% and 41.4% for each device. Results of the current study proved that the HCR can be an effective, promising and clean sludge treatment technique for use in wastewater treatment plants.

Polyhydroxyalkanoates (PHA) biosynthesis from kraft mill wastewaters: biomass origin and C:N relationship influence

2011 ◽  
Vol 63 (3) ◽  
pp. 449-455 ◽  
Author(s):  
G. Pozo ◽  
A. C. Villamar ◽  
M. Martínez ◽  
G. Vidal
Keyword(s):  
Chemical Oxygen Demand ◽  
Oxygen Demand ◽  
Paper Mill ◽  
Biological Oxygen Demand ◽  
Sludge Treatment ◽  
The Third ◽  
Batch System ◽  
Kraft Mill Effluent ◽  
Kraft Mill ◽  
Relationship Of

The goal of this study is to evaluate the feasibility of PHA biosynthesis from kraft mill effluent using the batch system evaluating the biomass origin and C:N relationship influence. To evaluate feasibility, batch assays were carried out. Also, two levels of the BOD5:N:P relationship (100:5:1 and 100:1:0.2) and three different sludge origins were considered. Inocula were obtained from activated sludge treatment plants for a) sewage (SAS), b) paper mill (PAS) and c) kraft (KAS). The results show that the maximum Biological Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) removal was 80.5% and 59.7% respectively using KAS as inoculum. In these assays, kinetics constants were 17.9±3.2 mg L−1 and 46.5±1.2 d−1 for (KCOD) and (rmax), respectively under a BOD5:N:P relationship of 100:5:1. The maximum PHA accumulation was obtained under a BOD5:N:P relationship of 100:1:0.2 on the third day of batch assays using PAS sludge with 25.72% of the cells accumulating PHA and on the fifth day in batch using SAS and KAS sludge with 25.85% and 30.40% of cells accumulating PHA, respectively. Yields obtained for the 100:1:0.2 relationships ranged from 0.10–0.14 mg PHA mg−1 COD.

scholarly journals The effect of hydrothermal treatment on industrial wastewater: Hungary as a case study

2020 ◽  
Author(s):  
Mahmood Al Ramahi ◽  
Sándor Beszédes ◽  
Gábor Keszthelyi-Szabó
Keyword(s):  
Chemical Oxygen Demand ◽  
Hydrothermal Treatment ◽  
Industrial Wastewater ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Sodium Absorption ◽  
Treatment Technique ◽  
Sodium Absorption Ratio ◽  
High Concentrations ◽  
Wastewater Samples

AbstractIndustrial wastewater is a growing environmental challenge due to its high concentrations of organics and its limited biological degradability. Up to date, however, no published work discussed industrial wastewater characterization, which is the focus of this study. Moreover, the effect of hydrothermal treatment on the chemical oxygen demand (COD) removal and the soluble chemical oxygen demand (SCOD) release was investigated in this work. Wastewater samples were collected from different industrial sites and characterized in order to determine their initial properties. It was summarized that the salinity of wastewater estimated by EC was relatively low, and its pH values were in the acceptable range. On the other hand, however, high values of sodium absorption ratio (SAR) were obtained in all samples post to hydrothermal treatment. Nonetheless, our results revealed higher SCOD release post to hydrothermal treatment suggesting better efficiency of COD removal obtained by this treatment technique.

scholarly journals Influence of ultrasound on the heterogeneous Fenton-like oxidation of acetic acid

2017 ◽  
Vol 76 (10) ◽  
pp. 2793-2801
Author(s):  
Aydın Cihanoğlu ◽  
Gönül Gündüz ◽  
Meral Dükkancı
Keyword(s):  
Acetic Acid ◽  
Chemical Oxygen Demand ◽  
Carboxylic Acids ◽  
Oxidation Process ◽  
Oxygen Demand ◽  
Hybrid Process ◽  
Ultrasonic Power ◽  
Heterogeneous Fenton ◽  
Cod Reduction ◽  
Ultrasonic Bath

Abstract The main objective of this study is to investigate the effect of ultrasound on the heterogeneous Fenton-like oxidation of acetic acid, which is one of the most resistant carboxylic acids to oxidation. For this purpose, firstly, the degradation of acetic acid was examined by using ultrasound alone and the effects of different parameters such as: type of sonication system, ultrasonic power, and addition of H2O2 were investigated on the degradation of acetic acid. There was no chemical oxygen demand (COD) reduction in the presence of sonication alone. In the presence of the heterogeneous Fenton-like oxidation process alone, at 303 K, COD reduction reached only 7.1% after 2 h of reaction. However, the combination of the heterogeneous Fenton-like oxidation process with ultrasound increased the COD reduction from 7.1% to 25.5% after 2 h of reaction in an ultrasonic bath operated at 40 kHz, while the COD reduction only increased from 7.1% to 8.9% in the ultrasonic reactor operated at 850 kHz. This result indicates that the hybrid process of ultrasound and heterogeneous Fenton-like oxidation is a promising process to degrade acetic acid.

The heterotrophic-combined-with-autotrophic denitrification process: performance and interaction mechanisms

2015 ◽  
Vol 71 (8) ◽  
pp. 1212-1218 ◽  
Author(s):  
Guihua Xu ◽  
Cuijie Feng ◽  
Fang Fang ◽  
Shaohua Chen ◽  
Yuanjian Xu ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Reduction Rate ◽  
Oxygen Demand ◽  
Process Performance ◽  
Autotrophic Denitrification ◽  
N Accumulation ◽  
Interaction Mechanisms ◽  
Molar Ratios ◽  
Denitrification Process ◽  
Heterotrophic Denitrification

In this work, the interaction mechanisms between an autotrophic denitrification (AD) and heterotrophic denitrification (HD) process in a heterotrophic-autotrophic denitrification (HAD) system were investigated, and the performance of the HAD system under different S/Ac− molar ratios was also evaluated. The results demonstrated that the heterotrophic-combined-with-autotrophic denitrification process is a promising technology which can remove chemical oxygen demand (COD), sulfide and nitrate simultaneously. The reduction rate of NO3− to NO2− by the HD process was much faster than that of reducing NO2− to N2, while the reduction rate of NO3− to NO2− by the AD process was slower than that of NO2− to N2. Therefore, the AD process could use the surplus NO2− produced by the HD process. This could alleviate the NO2−–N accumulation and increase the denitrification rate. In addition, the inhibition effects of acetate on AD bacteria and sulfide on HD were observed, and the inhibition was compensated by the promotion effects on NO2−. Therefore, the processes of AD and HD seem to react in parallel, without disturbing each other, in our HAD system.

scholarly journals Development of a Field Laboratory for Monitoring of Fecal-Sludge Treatment Plants

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1153
Author(s):  
Johannes Bousek ◽  
Marco Skodak ◽  
Magdalena Bäuerl ◽  
Georg Ecker ◽  
Jan Spit ◽  
...  
Keyword(s):  
Public Health ◽  
Fatty Acid ◽  
Chemical Oxygen Demand ◽  
Process Monitoring ◽  
Volatile Fatty Acid ◽  
Oxygen Demand ◽  
Humanitarian Aid ◽  
Sludge Treatment ◽  
Test Setup ◽  
Fecal Sludge

In urban humanitarian-aid operations, safe treatment of fecal sludge is highly important. While currently field-deployable fecal-sludge treatment plants are being developed, field-ready analytical equipment for process-control and public health monitoring is missing. Within the Microbial Sludge Quality project, a field laboratory was developed. A minimum set of parameters for the considered processes was developed through literature research. The analytical methods were tested on their field applicability and, if necessary, modified. The following methods were modified for field use: bacteriological analysis (sample homogenization and counting), chemical oxygen demand (sample digestion), volatile fatty acid–alkalinity titration (redesigned test setup), total solids (redesigned test setup), and ammonia determination (redesigned test setup). For bacteriological analysis, chemical oxygen demand, and total solids the modifications lead to highly comparable analytical results. The results obtained by the field methodology for volatile fatty acid–alkalinity titration and ammonia determination were sufficient for field-process monitoring; however, they did not correlate as well. To enable rapid startup of the laboratory during humanitarian-aid missions, it was developed to include analytical and support equipment. The usage of the developed laboratory should allow close-in-time process monitoring and public-health assessments of fecal-sludge treatment plants.

REMOVAL OF DYE AND CHEMICAL OXYGEN DEMAND (COD) REDUCTION FROM TEXTILE INDUSTRIAL WASTEWATER USING HYBRID BIOREACTORS

2014 ◽  
Vol 13 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Ghasem Najafpour Darzi ◽  
Reza Katal ◽  
Hossein Zare ◽  
Seyed Omid Rastegar ◽  
Poorya Mavaddat
Keyword(s):  
Chemical Oxygen Demand ◽  
Industrial Wastewater ◽  
Oxygen Demand ◽  
Cod Reduction

Spatio-temporal Variations in Water Quality Parameter Trends in River Waters

2018 ◽  
Vol 69 (10) ◽  
pp. 2940-2952 ◽  
Author(s):  
Martina Zelenakova ◽  
Pavol Purcz ◽  
Radu Daniel Pintilii ◽  
Peter Blistan ◽  
Petr Hlustik ◽  
...  
Keyword(s):  
Water Quality ◽  
Chemical Oxygen Demand ◽  
Quality Indicators ◽  
Water Resource Management ◽  
Oxygen Demand ◽  
Temporal Variations ◽  
Water Quality Parameter ◽  
Agricultural Activity ◽  
Water Quality Indicators ◽  
Nitrite Nitrogen

Evaluating trends in water quality indicators is a crucial issue in integrated water resource management in any country. In this study eight chemical and physical water quality indicators were analysed in seven river profiles in the River Laborec in eastern Slovakia. The analysed water quality parameters were biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), pH, temperature (t), ammonium nitrogen (NH4+-N), nitrite nitrogen (NO2--N), nitrate nitrogen (NO3--N), and total phosphorus (TP). Data from the monitored indicators were provided by the Ko�ice branch of the Slovakian Water Management Company, over a period of 15 years from 1999 to 2013. Mann�Kendall non-parametric statistical test was used for the trend analysis. Biochemical and chemical oxygen demand, ammonium and nitrite nitrogen content exhibit decreasing trends in the River Laborec. Decreasing agricultural activity in the area has had a significant impact on the trends in these parameters. However, NO2--N was the significant parameter of water quality because it mostly exceeds the limit value set in Slovak legislation, Regulation No. 269/2010 Coll. In addition, water temperature revealed an increasing trend which could be caused by global increase in air temperature. These results indicate that human activity significantly impacts the water quality.

scholarly journals Treatment of fish processing industry wastewater using hydrodynamic cavitational reactor with biodegradability improvement

2019 ◽  
Vol 80 (12) ◽  
pp. 2310-2319 ◽  
Author(s):  
Prashant Dhanke ◽  
Sameer Wagh ◽  
Abhijeet Patil
Keyword(s):  
Organic Matter ◽  
New Technology ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Hydrodynamic Cavitation ◽  
Inlet Pressure ◽  
Fish Processing ◽  
Processing Industry ◽  
Cavitation Effect ◽  
Processing Plants

Abstract Water generated from the fish processing industry is contaminated with organic matter. This organic matter present in wastewater increases the biochemical oxygen demand (BOD) and chemical oxygen demand (COD). A new technology, hydrodynamic cavitation (HC) is used to deal with this wastewater produced in fish processing plants. The orifice plate is used in the HC reactor to generate a cavitation effect. The intensification of this technique was carried out with the help of hydrogen peroxide (H2O2) and TiO2. The treatment of this wastewater is reported in terms of percent degradation in BOD and COD and in biodegradability index (BI). Operating parameters like inlet pressure, pH, operating temperature and H2O2 doses were used to find the optimum condition. 15 g/L of H2O2 gave 69.5% reduction of COD in the 120 min of treatment that also increases BI value to 0.93 at inlet pressure 8 bar, Plate-5, temperature (30 °C), and pH 4. In the ultrasonic cavitation (UC) reactor, COD reduction is 68.7% without TiO2 and with TiO2 it is 71.2%. Also, this HC and UC reactor reduced CFU count to a great extent at the same operating conditions.

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