scholarly journals Synthesis, Characterization, and Sludge Dewaterability Evaluation of the Chitosan-Based Flocculant CCPAD

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 95 ◽  
Author(s):  
Chunhong Shi ◽  
Wenquan Sun ◽  
Yongjun Sun ◽  
Lei Chen ◽  
Yanhua Xu ◽  
...  
Keyword(s):  
Intrinsic Viscosity ◽  
Ammonium Chloride ◽  
Ph Value ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Monomer Concentration ◽  
Carboxymethyl Chitosan ◽  
Sludge Dewatering ◽  
Illumination Time ◽  
Sludge Dewaterability

Carboxymethyl chitosan (CMCS), acrylamide, and methacryloxyethyltrimethyl ammonium chloride were used as co-monomers to produce a sludge dewatering agent carboxymethyl chitosan-graft-poly(acrylamide-methacryloxyethyltrimethyl ammonium chloride) (CCPAD) by UV-induced graft polymerization. Single-factor experiments and response surface methodology were employed to investigate and optimize the grafting rate, grafting efficiency, and intrinsic viscosity influenced by the total monomer concentration, CMCS concentration, cationic degree, pH value, and illumination time. The structure, surface morphology, and thermal stability of CCPAD were characterized by infrared spectroscopy, hydrogen nuclear magnetic resonance, X-ray diffraction, scanning electron microscopy, and differential thermal-thermogravimetry. The raw sludge with 97.9% water content was sourced from the concentrated tank of a sewage treatment plant and used in the sludge condition experiments. In addition, CCPAD was applied as the sludge conditioner to investigate the effects of cationic degree, intrinsic viscosity, and pH on the supernatant turbidity, moisture content, specific resistance to filtration, and sludge settling ratio. Moreover, the mechanism of sludge conditioning by CCPAD was discussed by examining the zeta potential and extracellular polymeric substance (EPS) content of the supernatant. The sludge dewatering results confirmed that CCPAD had excellent performance for improving sludge dewaterability.

scholarly journals UV-Initiated Polymerization of Cationic Polyacrylamide: Synthesis, Characterization, and Sludge Dewatering Performance

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Huaili Zheng ◽  
Yongjun Sun ◽  
Xiaomin Tang ◽  
Mingzhuo Tan ◽  
Jiangya Ma ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Light Intensity ◽  
Intrinsic Viscosity ◽  
Ammonium Chloride ◽  
Solid Content ◽  
Trimethyl Ammonium Chloride ◽  
Sludge Dewatering ◽  
Illumination Time ◽  
Rsm Model ◽  
Uv Initiation

P(AM-DAC-BA) was synthesized through copolymerization of acrylamide (AM), acryloyloxyethyl trimethyl ammonium chloride (DAC), and butylacrylate (BA) under ultraviolet (UV) initiation using response surface methodology (RSM). The influences of light intensity, illumination time, and photoinitiator concentration on the intrinsic viscosity[η]of P(AM-DAC-BA) were investigated. RSM model based on the influencing data was established for optimizing synthetic conditions. It was found that, at light intensity 1491.67 μw·cm−2, illumination time 117.89 min, and photoinitiator concentration 0.60‰, there was a better material performance achieved. Thus P(AM-DAC-BA) prepared under the above conditions showed excellent dewatering performance that, with 40 mg·L−1P(AM-DAC-BA) at pH 7, the residual turbidity of supernatant and the dry solid content were up to 38 NTU, 28.5%, respectively.

H2O2/UV-Initiated Copolymerization of Acrylamide and Dimethyl Diallyl Ammonium Chloride: Characterization and Flocculation Performance

2020 ◽  
Vol 12 (7) ◽  
pp. 1046-1054
Author(s):  
Yisen Li ◽  
Xinyu Zheng ◽  
Huaili Zheng
Keyword(s):  
Intrinsic Viscosity ◽  
Ammonium Chloride ◽  
Monomer Concentration ◽  
Urea Concentration ◽  
Illumination Intensity ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Illumination Time ◽  
Monomer Ratio

The cationic polyacrylamide flocculant P(AM-DMDAAC) is prepared by copolymerizing acrylamide (AM) and dimethyl diallyl ammonium chloride (DMDAAC) initiated by H2O2 under UV irradiation conditions. The structural features and thermal stability of P(AM-DMDAAC) are characterized via infrared spectroscopy, thermogravimetry/differential scanning calorimetry, and proton nuclear magnetic resonance spectroscopy. The effects of multiple factors, including monomer concentration, mass monomer ratio, illumination time, initiator H2O2 concentration, solution pH, illumination intensity, and urea concentration, on the intrinsic viscosity of P(AM-DMDAAC) are studied. The optimum preparation conditions are found to be 30% monomer concentration, 1:4 mass monomer ratio, 0.5‰ initiator concentration, 5.5 pH, 30 min illumination time, 1800 uW/cm2 illumination intensity, and 0.5% urea concentration. Under optimal conditions, the intrinsic viscosity of P(AM-DMDAAC) reaches 18.31 dL/g, which corresponds to a molecular weight of 9.6 × 10 6. Sludge dewatering experiments show that P(AM-DMDAAC) exhibits superior flocculating performance compared with other flocculants.

Comparison of lime and alum as oily sludge conditioners

1997 ◽  
Vol 36 (12) ◽  
pp. 117-124 ◽  
Author(s):  
Tay Joo Hwa ◽  
S. Jeyaseelan
Keyword(s):  
Specific Resistance ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oily Sludge ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Sludge Cake ◽  
Solids Content ◽  
Optimum Chemical

Chemical conditioning improves sludge dewatering. Choice of chemical conditioners is very much dependent on the characteristics of the sludges and the type of dewatering devices. Lime, alum, ferric chloride and polyelectrolytes are commonly used chemical conditioners. Anaerobic digested sludge samples collected from a sewage treatment plant with different oil contents varying from 1.8% to 8.0% by weight have been examined in the laboratory to find out their specific resistance, capillary suction time and filter yield. Lime and alum were used separately as conditioners. Different dosages of conditioner varying from 2% to 12% by weight were used to determine the optimum chemical dosage for varying oil contents. Lime dosages of about 6% were found to yield favourable characteristics. Addition of alum decreases the specific resistances and capillary suction times of oily sludges rapidly up to 4% dosages. Alum dosages beyond 4% only increase the solids content in the sludge cake and increase the sludge volume to be handled. A correlation between CST and specific resistance to filtration was established. CST can be measured easily and quickly in the laboratories. Using the CST and the correlation a quick prediction on dewaterability can be established.

Toxicity assays and their evaluation on organic polymer flocculants used for municipal sludge dewatering

1998 ◽  
Vol 38 (7) ◽  
pp. 207-215 ◽  
Author(s):  
H. Takigami ◽  
N. Taniguchi ◽  
Y. Shimizu ◽  
S. Matsui
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Algal Growth ◽  
Pilot Scale ◽  
Organic Polymer ◽  
Municipal Sludge ◽  
Sludge Dewatering ◽  
Algal Toxicity ◽  
Reproduction Tests

The toxicity of organic polymer flocculants used for the dewatering of municipal sludge was evaluated by using two different toxicity assays: the Closterium ehrenbergii algal toxicity test and the Bacillus subtilis rec-assay. The algal toxicity of the effluents from a pilot-scale sewage treatment plant was investigated with and without the addition of a flocculant (0, 0.05, 0.10 and 0.20 mg/L). No clear evidence on the toxicity caused by the flocculant was observed on both asexual and sexual reproduction tests of C. ehrenbergii. It was also found that the algal growth inhibition of various types of flocculants (i.e., cationic, anionic, amphoionic and non-ionic) was in the order of 1 to 20 mg/L, which was mainly due to a molecular weight (MW) fraction of greater than 100,000. The results of the B. subtilis rec-assay for these flocculants indicated that eight out of ten cationic flocculants caused the direct DNA damage with LC50 =0.1 to 10 mg/L. One of the genotoxic flocculants was also fractionated into their components by MW. The experimental results showed that the lethal effects were mainly contributed by the polymer fraction of MW greater than 100,000, although the genotoxicity was not detected in that fraction. Therefore, the detected genotoxicity of the flocculants could be caused by the combined effects of various components, such as polymers, oligomers, monomers and additives.

Control of Heavy Metals and Organochlorines Using the Oil from Sludge Process

1990 ◽  
Vol 22 (12) ◽  
pp. 249-258 ◽  
Author(s):  
T. R. Bridle ◽  
I. Hammerton ◽  
C. K. Hertle
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Control Mechanisms ◽  
Sludge Dewatering ◽  
Water Board ◽  
Unit Operations ◽  
Set Up

A four month pilot plant program, evaluating all unit operations comprising an integrated Oil from Sludge (OFS) plant has been successfully completed for the Sydney Water Board. The unit operations of sludge dewatering, drying and conversion to oil in the patented OFS reactor system were set up at the Malabar Sewage Treatment Plant in Sydney. Pilot testing of the char combustor was conducted off site. Extensive heavy metal and organochlorine monitoring across each unit operation has revealed the following information. There is no loss of contaminants across the dewatering and drying operations. With the exception of arsenic and mercury, all heavy metals fed to the OFS reactor are retained in the char. Greater than 75% of PCB's and 85% of HCB present in sludge are destroyed in the OFS reactor. Greater than 99.7% of the heavy metals fed to the fluid bed combustor are retained in the ash (with exception of mercury, which reported 3% in the flue gas). The FBC ash is classified non-hazardous, using the Toxic Characteristic Leaching Procedure.No organochlorines were detected in the dryer or FBC off-gases. The OFS technology offers decoupling of heavy metal and organochlorine control mechanisms, thus allowing each to be optimally controlled.

The Change of Environmental in Sewage Sludge Compost

2015 ◽  
Vol 733 ◽  
pp. 334-337
Author(s):  
Ang Li ◽  
Li Na Sun
Keyword(s):  
Moisture Content ◽  
Ph Value ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Sludge Disposal ◽  
Early Rise ◽  
Value Changes ◽  
Sludge Composting ◽  
Maturity Parameters

By aerobic composting bin type of sewage treatment plant sludge composting, through periodic sampling, research composting process temperature, moisture content, PH value changes and study the changes in compost maturity parameters of the DH. The results show that the compost temperature increased rapidly in the early rise in the first two days when fast to 50 degrees Celsius, in the tenth day decreased to room temperature; moisture content than the original sludge reduced by 40 percent to compost indicators; PH by reaction initial 6.2, and gradually becomes neutral and alkaline 7.8 biased. Experiments show that after aerobic sludge composting in temperature, moisture content, PH value terms have been reached sludge disposal requirements.

scholarly journals Study on Fluid-Rock Interaction and Reuse of Flowback Fluid for Gel Fracturing in Desert Area

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Tianbo Liang ◽  
Linjie Shao ◽  
Erdong Yao ◽  
Jie Zuo ◽  
Xiongfei Liu ◽  
...  
Keyword(s):  
Ph Value ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Reservoir Rock ◽  
Chemical Compositions ◽  
Desert Area ◽  
Rock Interaction ◽  
Flowback Water ◽  
Reservoir Conditions

Hydraulic fracturing requires a large volume of fresh water, which is difficult and expensive to obtain in the desert area such as Tarim Basin. Currently, flowback fluid is typically transported to the sewage treatment plant and then discharged after reaching environmental requirements; however, this is not only costly, but also a waste of water resource. Therefore, it is imperative to understand the potential interactions between fracturing fluid and reservoir rock, and then find solutions to reuse the flowback water for subsequent fracturing. In this study, once flowback fluid was directly collected from the field, its chemical compositions were analyzed; then, filtering, decoloring, and chelating methods were chosen to effectively remove or shield the unfavorable reintroduced components. Moreover, pH value was further tuned during different stages of the recycling process to ensure good gelation and cross-linking properties of guar. Cross-linked guar synthesized with the flowback fluid was evaluated in the lab through shear resistance tests and coreflood tests under the reservoir conditions; results indicated the recycled gel behaved similarly as the original gel, or even better. From this work, a cheap and effective treatment process was proposed to reuse the flowback fluid in the desert area.

scholarly journals Stability Analysis of Mechanical Sludge Dewatering Machine Frame Based on Numerical Simulation

2022 ◽  
Vol 2152 (1) ◽  
pp. 012047
Author(s):  
Li Chen
Keyword(s):  
Equivalent Stress ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Normal Operation ◽  
Motor Speed ◽  
Sludge Dewatering ◽  
Element Analysis ◽  
Operation Conditions ◽  
Interference Frequency

Abstract Sludge is the inevitable product of sewage treatment plant and sewage treatment. Before sludge treatment, dewatering is generally required. Mechanical sludge dewatering machine is a common sludge dewatering equipment. Due to the complex operation conditions, the stability of sludge dewatering machine frame directly affects its reliability. In this paper, a mechanical sludge dewatering machine frame as the research object, based on ANSYS Workbench finite element analysis platform, static analysis and modal analysis. The analysis results show that: under normal working conditions, the maximum variable of the frame is 0.07mm, which can effectively ensure the normal operation of the sludge dewatering machine; the equivalent stress is 4.22Mpa, which is far less than the Xu Yong stress of the material; the vibration of the first two modes of the frame is relatively concentrated, and the corresponding motor speed under the interference frequency is 1241.4-1595.4r/min, which should be avoided in the use process.

Automation and Optimisation of Centrifuge Sludge Dewatering

1989 ◽  
Vol 21 (10-11) ◽  
pp. 1319-1324 ◽  
Author(s):  
Gunter Schrank ◽  
Clive Murren
Keyword(s):  
Continuous Measurement ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Effective Control ◽  
Excess Sludge ◽  
Chemical Additives ◽  
Sludge Dewatering ◽  
Sludge Thickening ◽  
Very High

The dehydration of sewage treatment plant sludges has become one of the major problems in the treatment of waste Water. Very high costs, especially those of flocculation additives, increasingly call for optimisation of this phase of the process. Taking the dewatering of sludge by centrifugation as an example, two different approaches can be considered: mechanical excess sludge thickening without the use of additives and the dehydration of sewage sludge with use of chemical additives. A prerequisite of any automation is the reliable acquisition of data of the parameters required for control. Continuous measurement of the concentration of suspended solids in the sludge that is to be dewatered, of sludge flow and of the turbidity of the clear phase (centrate) leaving the centrifuge, make it possible to design several methods of effective control.

Study of Adsorbent Derived from Sewage Sludge Incineration Residue for the Removal of Ni2+ in Wastewater

2011 ◽  
Vol 474-476 ◽  
pp. 158-161 ◽  
Author(s):  
Jin Yong Liu ◽  
Xu Nan Ning ◽  
Zuo Yi Yang
Keyword(s):  
Sewage Sludge ◽  
Room Temperature ◽  
Ph Value ◽  
Removal Rate ◽  
Low Cost ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Sludge Incineration ◽  
Incineration Residue

Sewage sludge incineration residue was obtained from a sewage treatment plant in Guangzhou and used as a low-cost sorbent for removing Ni2+ from wastewaters. The adsorption effectiveness and their factors of Ni2+ in aqueous solutions were simulated detailed using the adsorbents of the sludge incineration residue. The simulation contents and the factors included the adsorption time, the pH of solution and the dosage of adsorbents and so on. The results showed that at room temperature, the adsorption equilibrium of Ni2+ can be achieved in 6h and the best pH value of the solution was about 7.0. The removal rates of Ni2+ were increased with the adsorbent concentration increasing and the optimal concentration of adsorbent was 10g/L with the initial concentration of Ni2+ less than 30mg/L.At the best adsorption conditions, the removal rate of Ni2+ reached more than 70%.

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