scholarly journals Influence of Digested Sludge Conditioning on the Dewatering Processes and the Quality of Sludge Liquid

2020 ◽  
Vol 27 (1) ◽  
pp. 151-164 ◽  
Author(s):  
Beata Bień ◽  
Jurand D. Bień
Keyword(s):  
Sewage Sludge ◽  
Oxygen Demand ◽  
Ultrasonic Field ◽  
Ammonium Nitrogen ◽  
Digested Sludge ◽  
Capillary Suction ◽  
Combined Action ◽  
Sludge Conditioning ◽  
Combination Of Methods

AbstractTo increase the dewatering effect, sewage sludge should be properly prepared before dewatering. Sludge conditioning is a process whereby sludge solids are treated with chemicals or various other means to improve dewatering characteristics of the sludge by reducing the specific resistance and compressibility of the sludge. The aim of the research was to determine the possibility of increasing the efficiency of sewage sludge dewatering by applying chemical agents and ultrasonic field. Some parameters, such as suspension, chemical oxygen demand (COD), phosphorus and ammonium nitrogen content in sludge supernatant, were also analysed. Digested sludge belonged to the group of hardly dewatered sludge, its capillary suction time (CST) was of high value (2639 s). The lowest CST value (88.5 s) was obtained for the unsonicated sludge prepared only with PIX 113 at a dose of 7.0 mg/g d.m. Both the dose and the type of chemicals used, as well as the time of sonication, had an impact on the changes occurring in sludge properties. The increase in mechanical dewatering efficiency was obtained by using a combination of methods applied for sludge preparation, where the sonication of sludge was used at the preliminary stage and followed by dosing chemical substances. This resulted in the reduction of sludge final hydration and changes of other parameters. In addition, combined action of PIX 113 and Zetag 8180 allowed to reduce the content of suspended solids and COD in sludge supernatant.

scholarly journals Conditioning of Sewage Sludge with Physical, Chemical and Dual Methods to Improve Sewage Sludge Dewatering

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5079
Author(s):  
Beata Bień ◽  
Jurand D. Bień
Keyword(s):  
Sewage Sludge ◽  
Ammonium Nitrogen ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Pressure Filtration ◽  
Technical Parameters ◽  
Combined Action ◽  
Final Water Content ◽  
Physical And Chemical ◽  
The Impact

The paper presents the impact of different methods of sewage sludge conditioning on the improvement of sludge dewatering during pressure filtration processes. The following conditioning methods were tested for sludge preparation: sonication, addition of organic and inorganic chemicals (Zetag 8180, PIX 113 and the combined action of both substances). The research covered: physical and chemical analysis of sewage sludge, measurement of capillary suction time as an indicator of sludge dewaterability, some technical parameters of sludge pressure filtration process and the analysis of filtrate to assess the degree of contamination. The results of the research showed that the final water content of the prepared sludge decreased, while the specific filtration resistance increased. Among the tested methods the best results of sludge dewatering effects were obtained for sonicated sludge and its preparation with inorganic coagulant PIX 113. The combined effect of sonication with the addition of chemicals Zetag 8180 and PIX113 to sludge allowed for the reduction of organic substances, ammonium nitrogen and phosphates in filtrate after sludge dewatering.

Changes of some sewage sludge parameters prepared with an ultrasonic field

1997 ◽  
Vol 36 (11) ◽  
pp. 101-106 ◽  
Author(s):  
January Bien ◽  
Lidia Wolny
Keyword(s):  
Sewage Sludge ◽  
Microscopic Analysis ◽  
Chemical Compounds ◽  
Ultrasonic Field ◽  
Water Removal ◽  
Vacuum Filter ◽  
Additional Criterion ◽  
New Methods ◽  
Sludge Conditioning

Studies of sewage sludge conditioning by ultrasonic field concentrate on determination of the increase of water removal effect, which depends on kind of sludge and chemical compounds used in the dewatering process. An attempt was made to find new methods of sludge preparation before dewatering. Tests presented here focused on digested and difficult dewatered sludge. The sludge was dewatered on a vacuum filter after conditioning with polyelectrolytes and the ultrasonic field. The microscopic analysis was an additional criterion to evaluate changes in the sludge structure after preparation. The polyelectrolyte dose of 3 mg/g d.m. sonicated within 15 sec. resulted in the 50% decrease of sludge volume. Results presented confirmed our previous experiences, concerning the relation between conglomerates of sludge and the effect of dewatering.

scholarly journals Migration and transformation of heavy metals during the microwave-assisted thermal hydrolysis of sewage sludge

2021 ◽  
Author(s):  
Chunsheng Qiu ◽  
Jinxin Zheng ◽  
Chenchen Wang ◽  
Bingbing Wang ◽  
Nannan Liu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Ecological Risk ◽  
Risk Index ◽  
Oxygen Demand ◽  
Microwave Treatment ◽  
Potential Ecological Risk ◽  
Ammonium Nitrogen ◽  
Thermal Hydrolysis ◽  
Microwave Assisted

Abstract The migration, transformation and ecological risk of heavy metals (Cr, As, Ni, Cu, Zn, Cd and Pb) in the sewage sludge during the microwave-assisted thermal hydrolysis process were investigated under different temperatures (80 °C, 100 °C, 120 °C, 140 °C, and 160 °C). The potential relationship between the bio-availability of heavy metals and the variables of microwave treatment, including pH, ammonium-nitrogen, soluble chemical oxygen demand, pH, soluble protein, soluble polysaccharide and volatile solid, was also explored. The results showed that the migration of heavy metals between solid-liquid phase mainly depended on the temperature. The percentage of all heavy metals (except Cu) in mobile (acid-soluble/exchangeable and reducible) forms decreased after microwave-assisted thermal hydrolysis treatment. The solubilization of compounds with C = O and O-H accompanied with the generation of organic and inorganic metal halides were also observed in the treated sludge through fourier transform infrared spectroscopy analysis. NH4+-N showed the highest negative correlation to the bio-availability of most heavy metals (except Cu and Cr) with coefficients (absolute value) over 0.87 (P < 0.05). VS showed a positive correlation to the bio-availability of most heavy metals (except Cu). The total potential ecological risk index (RI) decreased by 46.65% after microwave treatment at 160 °C.

scholarly journals Ultrasounds Energy as an Agent of Polyelectrolyte Modification Prior to Sewage Sludge Conditioning

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6165
Author(s):  
Lidia Wolny ◽  
Paweł Wolski
Keyword(s):  
Sewage Sludge ◽  
Chemical Compounds ◽  
Ultrasonic Field ◽  
Field Exposure ◽  
Field Frequency ◽  
Geometrical Characteristics ◽  
Sludge Conditioning ◽  
Quantitative Changes ◽  
Ultrasonic Modification ◽  
Shape And Size

The presented research concerned the phenomenon of polyelectrolyte changes resulting from modification by applying the ultrasonic field. The main aim of this research was to determine the activation degree of this macromolecular chemical compound and its effect on sewage sludge subjected to conditioning and followed by dewatering. The overall goal was to investigate the potential way of reducing the dosage of chemical compounds prior to sewage sludge conditioning. The polyelectrolyte samples were sonicated with the ultrasonic disintegrator UD-20 coupled with a sandwich concentrator. The power output of the generator was 180 W and the ultrasonic field frequency was 22 kHz. To describe the geometrical characteristics of the separated phases, the following parameters were determined: surface area (AA), perimeter (LA) and non-dimensional coefficient. With reference to the obtained results, the most significant quantitative changes in shape and size of the separated phases were observed for the ultrasonic field exposure time in the range of 0 to 10 s. This was in agreement with the results observed during dewatering of the investigated sewage sludge. In view of the quantitative analysis of the structure of the polyelectrolyte subjected to the ultrasonic modification, dewatering of sewage sludge was considerably improved by the application of the presented method.

scholarly journals Potential of anaerobic co-digestion in improving the environmental quality of agro-textile wastewater sludge

2020 ◽  
Author(s):  
Jean G. Tapsoba ◽  
Hans C. Komakech ◽  
Johnson Odera Ouma
Keyword(s):  
Heavy Metal ◽  
Sewage Sludge ◽  
Environmental Quality ◽  
Oxygen Demand ◽  
Wastewater Sludge ◽  
Effluent Treatment ◽  
Cow Dung ◽  
Biogas Yield ◽  
Textile Sludge

Abstract Sludge from textile effluent treatment plants (ETP) remains a challenge for many industries due to inefficient and limited waste management strategies. This study explores the potential of using anaerobic digestion (AD) to improve the environmental quality of textile ETP sludge. The AD of ETP sludge is affected by the low C/N ratio (3.7), heavy metal content, and toxicity. To improve the process, co-digestion of ETP sludge with different substrates (sewage sludge, cow dung, and sawdust) under mesophilic conditions (37 °C), followed by a thermochemical pretreatment was assessed. The results showed that anaerobic co-digestion of the textile sludge with the co-substrates is effective in reducing pollution load. It was found that organic matters degraded during the 30-day AD process. The chemical oxygen demand and biological oxygen demand reduction was in the range of 33.1–88.5% and 48.1–67.1%, respectively. Also, heavy metal (cadmium, lead, iron, and, mercury) concentration was slightly reduced after digestion. Maximal biogas yield was achieved from co-digestion of textile sludge and sewage sludge at a mixing ratio of 3:1, 1:1, and 1:3, and methane content was respectively 87.9%, 68.9%, and 69.5% of the gas composition. The results from this study show that co-digestion will not only reduce the environmental pollution and health risks from the textile industry but also recover useful energy.

NITRIFICATION OF SEWAGE SLUDGE USING MISCIBLE DISPLACEMENT AND PERFUSION TECHNIQUES

1975 ◽  
Vol 55 (4) ◽  
pp. 467-472 ◽  
Author(s):  
N. E. STEWART ◽  
C. T. CORKE ◽  
E. G. BEAUCHAMP ◽  
L. R. WEBBER
Keyword(s):  
Sewage Sludge ◽  
Flow Rate ◽  
Organic Nitrogen ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
Miscible Displacement ◽  
Digested Sludge ◽  
Displacement Experiments ◽  
Digested Sewage Sludge ◽  
Lower Flow Rate

Miscible displacement and soil perfusion techniques were used to study the transformations of nitrogen in fractions of anaerobically digested sewage sludge. In miscible displacement experiments the rates of nitrification of NH4+-N of supernates of sludge were 115 μg NO3−-N/g soil/day at a flow rate of 0.17 cm h−1, and 81 μg NO3−-N/g soil/day at the lower flow rate of 0.10 cm h−1. The soil perfusion experiments indicated that only the ammonium-nitrogen of the sludge solids was oxidized to nitrate-nitrogen. The rates of nitrification of sludge were 37 μg NO3−-N/g soil/day for an application of 5.0 cm ha−1 and 15 μg NO3−-N/g soil/day for a sludge application equivalent to 2.5 cm ha−1. The experiments were not of sufficient duration to determine that mineralization of the organic-nitrogen in the digested sludge and subsequent nitrification occurred.

scholarly journals Iron compounds and a magnetic field as the conditioning agents for municipal sewage sludge

2018 ◽  
Vol 45 ◽  
pp. 00022 ◽  
Author(s):  
Kamila Hrut ◽  
Tomasz Kamizela
Keyword(s):  
Magnetic Field ◽  
Sewage Sludge ◽  
Flow Direction ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Capillary Suction ◽  
Field Action ◽  
Time Test ◽  
Filter Cakes

The purpose of the research was to determine the possibility of using a magnetic field as a factor supporting the conditioning of municipal sewage sludge prepared using a chemical method. In order to condition the sludge, PIX 113 iron coagulant or Fe3O4 nanoparticles were used. Two types of organic flocculants: medium cationic Superfloc ® C-494 and high cationic Superfloc ® C-496 were also applied. For the various test combinations a capillary suction time test was performed, the specific resistance to filtration and the final filtration of the filter cakes were determined. For selected combinations, a quality of supernatants analysis was also performed, the measure of which was the COD values. The results show, that in the dual chemical conditioning method, the use of PIX 113 coagulant was more favorable than the nanoparticles Fe3O4. The influence of a magnetic field on the susceptibility to the dewatering of the tested sludge was variable, depending on process parameters such as the flow direction and flow rate through the solenoid. The type of polyelectrolyte used in the conditioning method with magnetic field action was also significant.

scholarly journals Prediction of Wastewater Quality at a Wastewater Treatment Plant Inlet Using a System Based on Machine Learning Methods

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 85
Author(s):  
Barbara Wodecka ◽  
Jakub Drewnowski ◽  
Anita Białek ◽  
Ewa Łazuka ◽  
Joanna Szulżyk-Cieplak
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Ammonium Nitrogen ◽  
Support Vector ◽  
Process Conditions ◽  
Wastewater Quality

One of the important factors determining the biochemical processes in bioreactors is the quality of the wastewater inflow to the wastewater treatment plant (WWTP). Information on the quality of wastewater, sufficiently in advance, makes it possible to properly select bioreactor settings to obtain optimal process conditions. This paper presents the use of classification models to predict the variability of wastewater quality at the inflow to wastewater treatment plants, the values of which depend only on the amount of inflowing wastewater. The methodology of an expert system to predict selected indicators of wastewater quality at the inflow to the treatment plant (biochemical oxygen demand, chemical oxygen demand, total suspended solids, and ammonium nitrogen) on the example of a selected WWTP—Sitkówka Nowiny, was presented. In the considered system concept, a division of the values of measured wastewater quality indices into lower (reduced values of indicators in relation to average), average (typical and most common values), and upper (increased values) were adopted. On the basis of the calculations performed, it was found that the values of the selected wastewater quality indicators can be identified with sufficient accuracy by means of the determined statistical models based on the support vector machines and boosted trees methods.

Behaviour of endocrine disrupting chemicals during the treatment of municipal sewage sludge

2004 ◽  
Vol 50 (5) ◽  
pp. 133-140 ◽  
Author(s):  
P. Ivashechkin ◽  
P.F.-X. Corvini ◽  
M. Dohmann
Keyword(s):  
Sewage Sludge ◽  
Calcium Hydroxide ◽  
Ph Value ◽  
Endocrine Disrupting Chemicals ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Digested Sludge ◽  
Endocrine Disrupting ◽  
Anaerobically Digested Sludge ◽  
Sludge Conditioning

Agricultural application of municipal sewage sludge has been emotionally discussed in the last decades, because the latter contains endocrine disrupting chemicals (EDCs) and other organic micro-pollutants with unknown fate and risk potential. Bisphenol A (BPA) was chosen as a model substance to investigate the influence of sludge conditioning on the end-concentration of EDCs in sludge. Adsorption studies with radioactive-labelled BPA showed that more than 75% BPA in anaerobically digested sludge is bound to solids (log Kd = 2.09-2.30; log Koc = 2.72-3.11). Sludge conditioning with polymer or iron (III) chloride alone had no influence on the adsorption of BPA. After conditioning with iron (III) chloride and calcium hydroxide desorption of BPA took place. Apparently, it occurred due to the deprotonation of BPA (pKa = 10.3) as the pH-value reached 12.4 during the process. The same behaviour is expected for other phenolic EDCs with similar pKa (nonylphenol, 17β-estradiol, estron, estriol, 17α-ethinylestradiol). This study shows high affinity of BPA to the anaerobically digested sludge and importance of conditioning in the elimination of EDCs during the sludge treatment. Addition of polymer is favourable in the case of sludge incineration. Conditioning with iron (III) chloride and calcium hydroxide shows advantages for the use of sludge as fertiliser.

Effect of the addition of rice straw on microbial community in a sewage sludge digester

2014 ◽  
Vol 70 (5) ◽  
pp. 819-827 ◽  
Author(s):  
E. Nakakihara ◽  
R. Ikemoto-Yamamoto ◽  
R. Honda ◽  
S. Ohtsuki ◽  
M. Takano ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Rice Straw ◽  
Dna Sequences ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Shannon Index ◽  
Methanosarcina Barkeri ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Digested Sludge ◽  
Capillary Suction

Rice straw was added to a sewage sludge digester and its effects on methane production, dewatering characteristics, and microbial communities in the digested sludge were examined by a continuous digestion experiment under mesophilic conditions (35 °C). Stable gas generation was monitored in all digestion experiments. Methane yield from raw sludge, chopped rice straw and softened rice straw were estimated to be 0.27, 0.18 and 0.26 NL/g total solids load, respectively. The capillary suction time of digested sludge was decreased by the addition of rice straw. Archaeal and bacterial communities in the sludge were elucidated by PCR-DGGE (polymerase chain reaction – denaturing gradient gel electrophoresis) targeting 16S rRNA genes. The Shannon index of DGGE profiles indicated that bacterial diversity increased with the addition of softened rice straw. DNA sequences of significant bands of the digested sludge were most closely related to Methanosaeta concilii (97.4% identity) and Methanoculleus bourgensis (100% identity). Meanwhile, those in the co-digested sludge with rice straw were most closely related to Methanosarcina barkeri (98.4% identity) and Methanoculleus bourgensis (99.3% identity). Although both Methanosaeta spp. and Methanosarcina spp. metabolize acetate to methane, Methanosarcina spp. have a competitive advantage at acetate concentrations of >70 mg/L. Results suggested that the quantity of acetate produced during rice straw degradation may change the archaeal community.

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