scholarly journals An Effective Flocculation Method to the Kaolin Wastewater Treatment by a Cationic Polyacrylamide (CPAM): Preparation, Characterization, and Flocculation Performance

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Badradine Zakaria Djibrine ◽  
Huaili Zheng ◽  
Moxi Wang ◽  
Shuang Liu ◽  
Xiaomin Tang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Wastewater Treatment ◽  
Ph Value ◽  
Incident Light ◽  
Monomer Concentration ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Illumination Time ◽  
Floc Size ◽  
Flocculation Test

P(AM-DMC) (PAD) was synthesized by ultraviolet- (UV-) initiated copolymerization with methacryloxyethyl trimethyl ammonium chloride (DMC) and acrylamide (AM) as the monomers and initiator 2,2-azobis [2-(2-imidazolin-2-yl) propane] dihydrochloride (VA-044) as the photoinitiator. Parameters that affect the molecular weight were reviewed by using the single-factor approach. The results showed that the molecular weight (MW) of PAD could come to 7.88 × 106 Da with the optimum polymerization conditions as follows: monomer concentration of 30%, monomer mass ratio m(AM) : m(DMC) of 3 : 1, initiator concentration of 0.6‰, illumination time of 80 min, solution pH value of 4.5, and incident light intensity of 1000 μW cm−2. The PAD was represented by several instruments. The results of FTIR and 1H NMR showed that PAD was indeed polymerized by AM and DMC. The results of TGA showed that PAD was very stable at room temperature while the result of SEM revealed that PAD had a porous structure and rough surface. For PAD used as flocculant in kaolin wastewater treatment, the results confirmed that, at optimal conditions, the turbidity and the floc size d50 could reach to 5.9 NTU and 565.936 μm, respectively, at the optimal conditions (pH = 7.0 and dosage = 2 mg l−1). Kaolin wastewater flocculation test outcome reveals that the PAD with high cationic degree and intrinsic viscosity could boost the charge neutralization and bridging capability. Consequently, the result is an excellent flocculation performance of treating kaolin wastewater.

Study on the Removal Effect of Chromium(VI) in Wastewater by Rice Husk

2014 ◽  
Vol 1073-1076 ◽  
pp. 825-828 ◽  
Author(s):  
Xue Min Dai ◽  
Shu Na Wang ◽  
Xia Wang
Keyword(s):  
Particle Size ◽  
Rice Husk ◽  
Ph Value ◽  
Removal Rate ◽  
Experimental Studies ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Adsorption Time ◽  
Chromium Vi

Rice husk was used as an adsorbent to study the adsorption of Cr (VI) from wastewater, Based on the experimental studies on influences of the particle size of rice husk, solution pH value, adsorption time, temperature and rice husk dose, the optimal conditions of the adsorption were determined as follows: temperature of 35°C, pH of 2, the particle size of rice husk in the range of 80-100 mesh, adsorption time of 3h, dose of 30g/0.2g. Under the optimal conditions, the removal rate of chromium from wastewater by rice husk can reach 91%.

scholarly journals Study on the removal of high contents of ammonium from piggery wastewater by clinoptilolite and the corresponding mechanisms

2019 ◽  
Vol 17 (1) ◽  
pp. 1393-1402
Author(s):  
Liu Nan ◽  
Li Yingying ◽  
Li Jixiang ◽  
Ouyang Dujuan ◽  
Wang Wenjuan
Keyword(s):  
Contact Time ◽  
Adsorption Process ◽  
Ph Value ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Piggery Wastewater ◽  
Column Study ◽  
Ammonium Removal ◽  
Ammonium Adsorption ◽  
Pseudo Second Order

AbstractIn this study, a clinoptilolite was applied to remove ammonium from piggery wastewater. The performance of ammonium removal and the correspondingly mechanisms were discussed. Under the optimal conditions of clinoptilolite dosage of 12 g/L, solution pH value of 8.3, shaking speed of 280 rpm and contact time of 55 min obtained by using response surface methodology (RSM), 19.7 mg of ammonium can be adsorbed onto 1 g of clinoptilolite, which was declined when metal cations were presented in the piggery wastewater. The ammonium adsorption process by the clinoptilolite can be well fitted by Langmuir isotherm with a spontaneous nature and pseudo–second–order kinetics model. Furthermore, column study showed that to some extent, the increased flow rate was beneficial to the removal of ammonium, and the ammonium adsorption capacity of clinoptilolite in column study was much higher than those in batch study.

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.

Research on Microbial Degradation of Bamboo Lignin for Extraction of Natural Bamboo Fiber

2013 ◽  
Vol 650 ◽  
pp. 273-278
Author(s):  
He Li ◽  
Guo Ying Zhou ◽  
Jian Liu ◽  
Sheng Jie Wang
Keyword(s):  
Microbial Degradation ◽  
Ph Value ◽  
Orthogonal Experiment ◽  
Bamboo Fiber ◽  
Ammonium Tartrate ◽  
Optimal Conditions ◽  
Buffer Solution ◽  
Solution Ph ◽  
Natural Bamboo Fiber ◽  
Liquid Quantity

This study optimizes on the technological conditions for extraction of natural bamboo fiber by means of microbial degradation of bamboo lignin. Results show that by the orthogonal experiment, we have studied out optimal conditions for combining three strains with fermentation to produce enzyme: 10.0 g/L glucose, 0.2 g/L ammonium tartrate, 4.5 buffer solution pH value and 20.0/250 ml loading liquid quantity. In these above four factors, the primary and secondary factors affecting enzyme production are: carbon source > pH value > loading liquid quantity > nitrogen source. Meanwhile, the experiment has studied the influence of single factor on lignin degradation: at the temperature of 37 °C, about 4 x 107spore concentration, adding 1.5 mg/L veratryl alcohol and introducing air at the efflux rate of 1 L/min are bamboo crude fiber optimal conditions for microbial selective degradation of lignin.

Removal of p-arsanilic acid and phenylarsonic acid from water by Fenton-coagulation process: influence of substituted amino group

2021 ◽  
Author(s):  
Qiang Peng ◽  
Wenze Xu ◽  
Weixiao Qi ◽  
Chengzhi Hu ◽  
Huijuan Liu ◽  
...  
Keyword(s):  
Emerging Contaminants ◽  
Ph Value ◽  
Inorganic Arsenic ◽  
Amino Group ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Arsanilic Acid ◽  
Coagulation Process ◽  
Coagulation Performance ◽  
Phenylarsonic Acid

Abstract Phenylarsonic acid compounds, which were widely used in poultry and swine production, are emerging contaminants due to their considerable solubility in water and the highly toxic inorganic arsenic species forming potential during their biotic and abiotic degradation in the natural environment. Herein, we investigated the optimal conditions to treat typical organoarsenic contaminants ( p -arsanilic acid ( p -ASA) and phenylarsonic acid (PAA)) in aqueous solution based on Fenton-coagulation process for oxidizing them and capturing the released inorganic arsenic, and elucidated the influence mechanism of substituted amino group on removal. Results showed that the pH value and the dosage of H 2 O 2 and Fe 2+ significantly influenced the performance of the oxidation and coagulation processes. The optimal conditions for removing 20mg L -1 -As in this research were: 40mg L -1 Fe 2+ and 60mg L -1 H 2 O 2 (the mass ratio of Fe 2+ /H 2 O 2 = 1.5), initial solution pH of 3.0 and final solution pH of 5.0 adjusting after 30 min Fenton oxidation reaction. Meanwhile, the substituted amino group observably influence the oxidation and coagulation performance of phenylarsonic acid compounds. Amino group could make phenylarsonic acid compounds more easily be attacked by ·HO and supply more binding sites for forming complexes with Fe 3+ hydrolysates, resulting in higher oxidation rate and better coagulation performance.

BIOGAS PRODUCTION IN THE CONCENTRATED DISTILLERY WASTEWATER TREATMENT

2018 ◽  
pp. 51-59 ◽  
Author(s):  
N. Golub ◽  
M. Potapova ◽  
M. Shinkarchuk ◽  
O. Kozlovets
Keyword(s):  
Wastewater Treatment ◽  
Dry Matter ◽  
Ph Value ◽  
Biogas Production ◽  
Anaerobic Sludge ◽  
Methane Formation ◽  
Maximum Output ◽  
Processing Technologies ◽  
Spent Wash ◽  
Distillery Spent Wash

The paper deals with the waste disposal problem of the alcohol industry caused by the widespread use of alcohol as biofuels. In the technology for the production of alcohol from cereal crops, a distillery spent wash (DSW) is formed (per 1 dm3 of alcohol – 10–20 dm3 DSW), which refers to highly concentrated wastewater, the COD value reaches 40 g O2/dm3. Since the existing physical and chemical methods of its processing are not cost-effective, the researchers develop the processing technologies for its utilization, for example, an anaerobic digestion. Apart from the purification of highly concentrated wastewater, the advantage of this method is the production of biogas and highquality fertilizer. The problems of biotechnology for biogas production from the distillery spent wash are its high acidity–pH 3.7–5.0 (the optimum pH value for the methanogenesis process is 6.8–7.4) and low nitrogen content, the lack of which inhibits the development of the association of microorganisms. In order to solve these problems, additional raw materials of various origins (chemical compounds, spent anaerobic sludge, waste from livestock farms, etc.) are used. The purpose of this work is to determine the appropriate ratio of the fermentable mixture components: cosubstrate, distillery spent wash and wastewater of the plant for co-fermentation to produce an energy carrier (biogas) and effective wastewater treatment of the distillery. In order to ensure the optimal pH for methanogenesis, poultry manure has been used as a co-substrate. The co-fermentation process of DSW with manure has been carried out at dry matter ratios of 1:1, 1:3, 1:5, 1:7 respectively. It is found that when the concentration of manure in the mixture is insufficient (DSW/manure – 1:1, 1:3), the pH value decreases during fermentation which negatively affects methane formation; when the concentration of manure in the mixture is increased (DSW/manure – 1:5, 1:7), the process is characterized by a high yield of biogas and methane content. The maximum output of biogas with a methane concentration of 70 ± 2% is observed at the ratio of components on a dry matter “wastewater: DSW: manure” – 0,2:1:7 respectively. The COD reduction reaches a 70% when using co-fermentation with the combination of components “wastewater: DSW: manure” (0,3:1:5) respectively.

Ecological aspects of modernization of alcohol industry enterprises at the present stage of development

2020 ◽  
Vol 5 (3) ◽  
pp. 179-184
Author(s):  
Marianna Havryshko ◽  
◽  
Olena Popovych ◽  
Halyna Yaremko ◽  
◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Food Industry ◽  
Ph Value ◽  
Negative Impact ◽  
Water Bodies ◽  
Raw Material ◽  
Present Stage ◽  
Alcohol Industry ◽  
Stage Of Development ◽  
World Industry

At the present stage of development, the entire world industry has faced the problem of rational use of renewable natural resources, in particular the most efficient ways of wastewater treatment and the use of accumulated waste in the production process as a secondary raw material. In particular, the alcohol industry, as one of the components of food, medical, chemical and various industries,leads to the formation of huge amounts of waste, including wastewater. The food industry, like any other industry, has a negative impact on the environment. Water bodies are the most affected by the food industry. Almost the first place in terms of water consumption per unit of production is the production of alcohol. Consumption of large amounts of water leads to the formation of wastewater, which is highly polluted and adversely affects the environment. Due to the high chemical and biological consumption of oxygen, specific color and odor, suspended solids, low pH value, the purification of such waste in the filtration fields and discharge into water bodies is not possible. The purpose of our work is: 1) conducting the analysis of the alcohol industry potential in Ukraine in recent years, and methods of waste disposal as a potential source for the development of bioenergy. 2) environmental aspects of the alcohol industry modernization at present stage of development and implementation of modern wastewater treatment technologies.

Floc size distribution and bacterial activities in membrane separation activated sludge processes for small-scale wastewater treatment/reclamation

1997 ◽  
Vol 35 (6) ◽  
pp. 37-44 ◽  
Author(s):  
Boran Zhang ◽  
Kazuo Yamamoto ◽  
Shinichiro Ohgaki ◽  
Naoyuki Kamiko
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Membrane Separation ◽  
Small Scale ◽  
Nitrification Rate ◽  
Floc Size ◽  
Denitrification Activity ◽  
Concentration Changes ◽  
Activated Sludge Processes

Activated sludges taken from full-scale membrane separation processes, building wastewater reuse system (400m3/d), and two nightsoil treatment plants (50m3/d) as well as laboratory scale membrane separation bioreactor (0.062m3/d) were analyzed to characterize membrane separation activated sludge processes (MSAS). They were also compared with conventional activated sludges(CAS) taken from municipal wastewater treatment plants. Specific nitrification activity in MSAS processes averaged at 2.28gNH4-N/kgMLSS.h were higher than that in CAS processes averaged at 0.96gNH4-N/kgMLSS.h. The denitrification activity in both processes were in the range of 0.62-3.2gNO3-N/kgMLSS.h without organic addition and in the range of 4.25-6.4gNO3-N/kgMLSS.h with organic addition. The organic removal activity in nightsoil treatment process averaged at 123gCOD/kgMLSS.h which was significantly higher than others. Floc size distributions were measured by particle sedimentation technique and image analysis technique. Flocs in MSAS processes changed their sizes with MLSS concentration changes and were concentrated at small sizes at low MLSS concentration, mostly less than 60 μm. On the contrary, floc sizes in CAS processes have not much changed with MLSS concentration changes and they were distributed in large range. In addition, the effects of floc size on specific nitrification rate, denitrification rate with and without organic carbon addition were investigated. Specific nitrification rate was decreased as floc size increased. However, little effect of floc size on denitrification activity was observed.

scholarly journals Characterization of efficient xylanases from industrial-scale pulp and paper wastewater treatment microbiota

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jia Wang ◽  
Jiawei Liang ◽  
Yonghong Li ◽  
Lingmin Tian ◽  
Yongjun Wei
Keyword(s):  
Wastewater Treatment ◽  
Xylanase Activity ◽  
Pulp And Paper ◽  
Optimal Conditions ◽  
Paper Wastewater ◽  
Termite Hindgut ◽  
Uncultured Microorganisms ◽  
Metagenomic Approach ◽  
Gh10 Family

AbstractXylanases are widely used enzymes in the food, textile, and paper industries. Most efficient xylanases have been identified from lignocellulose-degrading microbiota, such as the microbiota of the cow rumen and the termite hindgut. Xylanase genes from efficient pulp and paper wastewater treatment (PPWT) microbiota have been previously recovered by metagenomics, assigning most of the xylanase genes to the GH10 family. In this study, a total of 40 GH10 family xylanase genes derived from a certain PPWT microbiota were cloned and expressed in Escherichia coli BL21 (DE3). Among these xylanase genes, 14 showed xylanase activity on beechwood substrate. Two of these, PW-xyl9 and PW-xyl37, showed high activities, and were purified to evaluate their xylanase properties. Values of optimal pH and temperature for PW-xyl9 were pH 7 and 60 ℃, respectively, while those for PW-xyl37 were pH 7 and 55 ℃, respectively; their specific xylanase activities under optimal conditions were 470.1 U/mg protein and 113.7 U/mg protein, respectively. Furthermore, the Km values of PW-xyl9 and PW-xyl37 were determined as 8.02 and 18.8 g/L, respectively. The characterization of these two xylanases paves the way for potential application in future pulp and paper production and other industries, indicating that PPWT microbiota has been an undiscovered reservoir of efficient lignocellulase genes. This study demonstrates that a metagenomic approach has the potential to screen efficient xylanases of uncultured microorganisms from lignocellulose-degrading microbiota. In a similar way, other efficient lignocellulase genes might be identified from PPWT treatment microbiota in the future.

Breaking Down the Supramolecular Ensemble: Single-Molecule Studies of the Concentration Dependence of Main-Chain Supramolecular Polymer Molecular Weight Distributions on Surfaces

2010 ◽  
Vol 63 (4) ◽  
pp. 624
Author(s):  
Michael J. Serpe ◽  
Jason R. Whitehead ◽  
Stephen L. Craig
Keyword(s):  
Molecular Weight ◽  
Single Molecule ◽  
Monomer Concentration ◽  
Supramolecular Polymer ◽  
Force Microscopy ◽  
Molecular Weight Distributions ◽  
Atomic Force ◽  
Multi Stage ◽  
Single Molecule Studies ◽  
Supramolecular Ensemble

Single molecule atomic force microscopy (AFM) studies of oligonucleotide-based supramolecular polymers on surfaces are used to examine the molecular weight distribution of the polymers formed between a functionalized surface and an AFM tip as a function of monomer concentration. For the concentrations examined here, excellent agreement with a multi-stage open association model of polymerization is obtained, without the need to invoke additional contributions from secondary steric interactions at the surface.

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