Flocculation Method Research Articles

Pengolahan Lindi (Leachate) dengan Metode Koagulasi – Flokulasi dan Sedimentasi Menggunakan Koagulan Aluminium Sulfate (Al2SO4) dan Poly Alumunium Chloride (PAC)

One of the TPSTs in Sidoarjo Regency is a place that is designated for the collection, sorting, reuse, recycling, processing and final processing of waste. These activities cause environmental problems that come from waste water called leachate. So that it is necessary to have a process that can reduce the contaminant content in leachate. This study aims to treat leachate from one of the TPSTs in Sidoarjo Regency with the coagulation - flocculation and sedimentation method using Aluminum Sulfate (Al2SO4) and Poly Aluminum Chloride (PAC) coagulants. The coagulation - flocculation and sedimentation process uses a 1: 3 dilution with a value of one for leachate and a value of three for air. The stirring speed of the coagulation was 120 rpm for 10 minutes, the flocculation was 45 rpm for 20 minutes and the sedimentation process was 24 hours. From the results of parameter measurement for each coagulant variation, it can be concluded that the Al2SO4 coagulant with a dose of 16 g / L is added to the leachate sample, the smaller the pH, TDS, TSS, BOD5 and COD values of the leachate. Whereas the addition of PAC coagulant at a dose of 30 g / L, the smaller the NH4-N value in leachate

Yeast assisted algal flocculation for enhancing nutraceutical potential of Chlorella pyrenoidosa

The present research describes yeast assisted algal flocculation followed by evaluation of algae-yeast flocs for nutritional profile as potent food product. Co-flocculation of Chlorella pyrenoidosa using Saccharomyces cerevisiae showed 58.33 ± 2.37% flocculation efficiency. Nutrient composition of algae-yeast flocs (CP-Y) depicted higher protein content (35.52%) as compared to algae (23.72%) and yeast biomass (33.89). Amino acid profiles of CP-Y biomass depicted increase in essential amino acid content with higher ratio of essential to non-essential amino acid (0.68) as compared to Y (0.57) and CP (0.57) biomass. Lipid and carbohydrate content of CP-Y flocs was estimated as 26.95 ± 0.57% and 21.12 ± 0.83%, respectively. Fatty Acid Methyl Esters (FAME) analysis showed presence of omega rich polyunsaturated fatty acids (PUFAs) like α-linolenic acid (ω-3), Linoleic acid (ω-6), Palmitoleic acid (ω-7) etc in CP-Y biomass. The study provides novel insights on nutrition enriched biomass obtained after algal-yeast flocculation, which can be a better alternative to existing flocculation methods for food applications.

Development of an effective flocculation method by utilizing the auto-flocculation capability of Phaeodactylum tricornutum

Phaeodactylum tricornutum (P. tricornutum) is a model and unique species of marine diatom with high lipid content and rapid growth. Alkaline flocculation is considered as a potential method to concentrate microalgae biomass, which is critical for large-scale cultivation and harvesting. In this study, we developed an effective approach to the traditional alkaline flocculation method by utilizing the auto-flocculation ability of P. tricornutum. We studied the performance and mechanism of auto-flocculation by comparing the inorganic and organic processes, assisted by scanning electron microscope (SEM), X-ray diffraction (XRD), and zeta potential. And we found that the role of algae growth in mediating Mg(OH)2 precipitation was not only to help increase pH but also adsorb divalent cations around the cell wall, which thus made algae cells the seeds facilitating Mg(OH)2 precipitation. We thus discovered a new pathway named “wrapping-sedimentation” during the auto-flocculation process, besides the charge neutralization and sweeping mechanisms. Through the auto-alkaline flocculation method, higher harvesting efficiency with at least a 2/3 reduction in alkali addition could be achieved.

Effect of the Processing on the Resistance-Strain Response of Multiwalled Carbon Nanotube/Natural Rubber Composites for Use in Large Deformation Sensors.

The dispersion, electrical conductivities, mechanical properties and resistance–strain response behaviors of multiwalled carbon nanotube (MWCNT)/natural rubber (NR) composites synthesized by the different processing conditions are systematically investigated at both macro- and micro-perspectives. Compared with the solution and flocculation methods, the two roll method produced the best MWCNTs distribution since the materials are mixed by strong shear stress between the two rolls. An excellent segregated conductive network is formed and that a low percolation threshold is obtained (~1 wt.%) by the two roll method. Different from the higher increases in conductivity for the composites obtained by the solution and flocculation methods when the MWCNT content is higher than 3 wt.%, the composite prepared by the two roll method displays obvious improvements in its mechanical properties. In addition, the two roll method promotes good stability, repeatability, and durability along with an ultrahigh sensitivity (GFmax = 974.2) and a large strain range (ε = 109%). The ‘shoulder peak’ phenomenon has not been observed in the composite prepared by the two roll method, confirming its potential for application as a large deformation monitoring sensor. Moreover, a mathematical model is proposed to explain the resistance–strain sensing mechanism.

What Affects Dewatering Performance of High Density Slurry?

The dewatering of flocculated high density slurry presents a significant challenge to most mining industries. The new technologies to treat high density slurry require a consistent and robust flocculation method in order to enter the market of tailings management. The flocculation of high density slurry, however, due to its complexity, is always a challenge to be undertaken appropriately and to evaluate the dewatering performance correctly. This paper probes the complexity by using a torque-controlled mixing technique to demonstrate the influence of feed properties, polymer type, polymer dosage, and mixing conditions on dewatering performance. The study shows that flocculant should be dosed at the optimal range to achieve the highest dewatering performance. A full dosage responsive curve including under dosage, optimal dosage, and overdosage is critical to evaluate the dewatering performance of high density slurries and flocculants. The mixing conditions such as mixing speed, mixing time, and geometry of the mixing impeller affect the flocculation efficacy. It was found that the dewatering performance of high density slurry is sensitive to solids content, water chemistry, and clay activity. High sodicity and high clay activity in the high density slurry decreases the dewatering performance. Therefore, it is critical to evaluate flocculants across multiple feeds and dosages with replication in order to select optimal dewatering performance. Using multiple key performance indicators (KPIs) to build technical and economic criteria is also critical for polymer evaluation.

Virological Characterization of Roof-Harvested Rainwater of Densely Urbanized Low-Income Region.

Roof-harvested rainwater (RHRW) is considered relatively clean water, even though the possible presence of pathogens in the water may pose human health risks. In this study, we investigated the occurrence of enteric viruses in the first flush (10mm) of RHRW from a densely populated and low-income urbanized region of Rio de Janeiro. One hundred samples (5 L) were collected from 10 rainfall events between April 2015 and March 2017. RNA and DNA viruses were concentrated using the skimmed milk flocculation method and analyzed using the TaqMan® quantitative RT-qPCR and qPCR. Human adenoviruses, noroviruses, rotaviruses A, and avian parvoviruses were detected in 54%, 31%, 12%, and 12% of the positive samples. JC polyomavirus, also targeted, was not detected. Virus concentrations ranged from 1.09 × 101 to 2.58 × 103 genome copies/Liter (GC/L). Partial nucleotide sequence confirmed the presence of HAdV type 41, norovirus genotype GII.4, and avian parvovirus 1. The results suggest that the first flush diversion devices may not adequately remove enteric virus from the rainwater. Additional treatment of RHRW is required to mitigate potential health risks from potable use of captured water.

Flocculation-based methods of microalgae removal from the eutrophic pond enrichment culture

Abstract The method of flocculation of biomass from the water depth to the bottom can be applied in case of local algae blooms. In our research, the combined application of FeCl3 and Polyethyleneoxide-based cationic flocculant was applied for the first time for the harvesting of the enrichment culture obtained from the reservoir during eutrophication. The effects of coagulant (FeCl3·6H2O), various flocculants based on polyacrylamide (PAA), polyethylenoxide (PEO) and flocculated biomass as ballast agent, dosage and sedimental time on flocculation efficiency of harvesting enrichment culture obtained from Pond Chernoistochinsky during eutrophication have been studied. The results show that the flocculation efficiency achieved about 90% after 5 min of sedimentation when adding coagulant and flocculant mixture (FeCl3 30 mg/L + PEO based Sibfloc-718 2.5 mg/L) or flocculant with ballast agent (FeCl3 30 mg/L + Sibfloc-718 2.5 mg/L + 1,7% flocculated biomass). PAA, PEO and FeCl3·6H2O did not demonstrate a sufficient flocculation capacity with enrichment culture containing different types of microalgae.

Research on the integration of flue gas desulfurization and dust removal in oil shale refining

The flue gas of oil shale retort is characterized by high humidity, low sulfur content and tar content, which makes it impossible for traditional flue gas desulfurization facilities to deal with such flue gas normally. By collecting flue gas parameters at the inlet and outlet of the original desulfurization tower of oil shale dry distillation flue gas, and combining with computational fluid dynamics numerical simulation, this paper analyzes the fault reasons of each step in the process of desulfurization of oil shale dry distillation flue gas. Through experimental study, the flocculation characteristics of suspended solids and petroleum substances in desulfurization circulating liquid were analyzed. The results show that the low concentration of Na2CO3, Ca(HO)2, CaO desulfurizer can promote the flocculation, Ca(HO)2, CaO desulfurizer is beneficial to the removal of petroleum substances. The original wet limestone-gypsum desulfurization system was transformed into the wet sodium carbonate desulfurization and dust removal integrated system. The method of flocculation and sedimentation is used to remove sludge and petroleum substances, which can ensure the normal operation of the system and the emission of flue gas up to the standard.

Treatment of Cutting Oil-in-Water Emulsion by Combining Flocculation and Fenton Oxidation

Recently, the disposal of waste oil-in-water cutting emulsion has become an urgent issue because of its extremely high chemical oxygen demand (COD). The present work focuses on treating the waste cutting emulsion generated from the Samsung Thai-Nguyen factory in Vietnam. This work used multistage methods to treat the waste cutting emulsion to meet the wastewater disposal requirement and characterize the oil recovered. The multistage methods consist of the flocculation method (stage 1) and Fenton oxidation (stage 2). The wastewater after stage 1 treatment has a COD reduction efficiency of 98.24% at the condition of pH 5, Al2(SO4)3 2 g/L, C-PAM 12 mg/L, stirring speed 50 rpm, and stirring time 15 minutes. At that condition, the COD value decreased from 147200 mg/L to 2484 mg/L. After stage 2, the COD value further decreased from 2484 mg/L to 85.4 mg/L with total COD removal efficiency increasing to 99.9% at the optimum conditions of pH 3, H2O2 : FeSO4 concentration ratio of 10 : 1, and FeSO4 concentration of 14.04 g/L. After the stage 2 treatment, the wastewater with the COD value of 85.4 mg/L and BOD5 value of 30 mg/L satisfied the Vietnam standard grade B and grade A, respectively, for industrial wastewater. The oil recovered from the treatment has a heating value of 38095 ± 8 kJ/kg, and thus, it could be reusable as fuel gas.

Comparison of Skimmed Milk and Lanthanum Flocculation for Concentration of Pathogenic Viruses in Water

Concentration of viruses in water is necessary for detection and quantification of the viruses present, in order to evaluate microbiological barriers in water treatment plants and detect pathogenic viruses during waterborne outbreaks, but there is currently no standardised procedure. In this study, we implemented a previously described fast and simple lanthanum-based protocol for concentration of norovirus genogroup I (GI), genogroup II (GII) and hepatitis A virus (HAV) in drinking and surface water. We compared the results with those of a widely used skimmed milk flocculation method, followed by nucleic acid extraction and RT-qPCR detection. Three seeding levels, with intended concentrations 5 × 103, 5 × 104 and 5 × 105 genome copies/10 L, were added to drinking water or surface water. All seed levels were detected with both flocculation methods. Samples extracted with skimmed milk flocculation had on average 1.82, 1.86 and 1.38 times higher measured concentration of norovirus GI, GII and HAV, respectively, than those extracted with lanthanum flocculation, across all seeding levels and water types tested. Mengovirus was used as a positive process control. Mengovirus recovery was higher for skimmed milk (40.7% in drinking water, 26.0% in surface water) than for lanthanum flocculation (24.4% in drinking water, 9.7% in surface water). Together, this indicates that skimmed milk flocculation provides higher viral recovery than lanthanum flocculation. However, lanthanum-based flocculation can be performed much faster than skimmed milk flocculation (1.5 h versus 16 h flocculation time) and thus could be a good alternative for rapid monitoring of viruses in water.

Intelligent control system for flocculation of water supply

Flocculation which affects the quality of water supply is the main step of water treatment. The most commonly used control method for flocculation is the streaming current detection-based control method using a single-loop feedback. However, the traditional control system cannot adapt to the change of raw water’s quality, the set value of streaming current can only be adjusted manually. In order to solve this problem, an intelligent control system for flocculation of water supply is designed based on the neural network and fuzzy control to adjust the set value of streaming current and tune the control parameters automatically in this study. The experimental results show that the proposed intelligent control system can control the flocculant dosage accurately. It is of great significance to improve the quality of water supply and reduce the cost of water treatment.

Evaluation of Influencing Factors of the Flocculation Process Waste Emulsion Cutting Oil to Reduce COD Parameters

Waste emulsion cutting oil has a very high COD (Chemical Oxygen Demand) and it was very harmful to the environment. In this study, flocculation method was investigated to reduce COD of the waste emulsion cutting oil discharged from Samsung, Thai-nguyen company. The waste emulsion cutting oil with the initial parameters such as oil content of 5.35%v/v; pH = 8.72; COD = 147,200 mg/l was used. Particle size and its distribution of the emulsion were determined by laser scattering. Results showed that the particle size of the emulsion has a narrow characteristic ranging from 0.058 to 1.729 µm, averaged at 0.22 µm. Several factors affecting to the flocculation process were pH (ranging from 3 to 10); Al2(SO4)3 content; C-PAM content and stirring speed during treatment of emulsion cutting oil. The best efficiency in COD reduction obtained was 98.24% (COD is 2,586 mg/l) at the optimum condition of pH = 5; Al2(SO4)3 of 2 g/l; C-PAM of 12 mg/kg at a stirring speed of 50 rpm for 25 minutes.

Effect of adsorption processes on oil-containing water purification by flocculation method

The results of the study of the processes of adsorption of cationic flocculants of the “Praestol” brand on sorbents obtained by non-chemical processing of clays of the Astrakhan region, the Volga deposit are presented. The adsorption models of Langmuir, Freundlich, and Temkin were used to describe experimental adsorption isotherms. The parameters of the intensity and efficiency of the sorption process are calculated. A comparative analysis of the obtained constants corresponding to these models is carried out and the most preferred model is determined, taking into account the coefficient of determination. It is established that the Freundlich model is most preferable for adsorption in the cationic flocculant – clay system, which allows us to confidently assume that the surface of the natural materials under consideration contains a large number of energetically heterogeneous active centers and is heterogeneous. The results of the analysis of the adsorption of flocculants on clays showed that this process improves flocculation. The bigger value of parameter of intensity of n from Friendlich’s equation for Praestol 853BC flocculant, confirms a greater influence of sorption on flocculating effect that it is connected with formation of the strong high-viscosity sewed structures on a surface of a firm phase. Experiments on the purification of water from oil by test flocculation were also delivered and the degree of purification efficiency was calculated.

Study on the Removal of Nitrogen-containing Waste outside the Aquaculture Pond by the Method of Electric Flocculation and Quasi Circulating Aquaculture

When the waste containing ammonia nitrogen is removed by electric flocculation circulating aquaculture, not only the colloidal impurities and suspended impurities are coagulated and precipitated, but also a variety of pollutants and bacteria in the water can be removed due to the oxidation of the anode and the reduction of the cathode. In this project, PWM (pulse width modulation) technology is used to overcome the power consumption problem of traditional electric flocculation method, high-voltage pulse and anode-cathode pole exchange technology is used to overcome the iron consumption and plate passivation problem, and echelon potential method is used to solve the difficulty of plate exchange. Compared with the traditional chemical and biological treatment technology, electrocoagulation can ensure the sustainable development of aquaculture without adding oxidants, flocculants and other chemicals. At present, electronic technology and Internet of things technology are used in aquaculture fields to monitor the water quality data in the pond and control the growth of aquaculture organisms in the most suitable environment in real time, so as to increase income, reduce human power and save water and electricity. Therefore, with mature sensing technology, IOT, Im, cloud computing, big data and AI, we can build an intelligent aquaculture production, marketing and digital service system to improve the overall production efficiency, energy and quality, and accelerate the transformation of aquaculture industry.

Evaluation of electrocoagulation, flocculation, and sedimentation harvesting methods on microalgae consortium grown in anaerobically digested abattoir effluent

Microalgae dewatering is a major bottleneck for biomass production in a large-scale microalgal production system which accounts for 20–60% of production cost. In this study, three dewatering systems of electrocoagulation, flocculation, and pH-induced flocculation were evaluated for microalgal consortium grown in anaerobically digested abattoir effluent at pH 6.5 and 9.5. At the shortest time (15 min) and the highest current density (0.08 A cm−2), the highest microalgae recoveries of 78 and 84% were obtained with the corresponding power consumptions of 1.25 and 1.07 kWh kg−1 for cultures at pH 6.5 and 9.5. For microalgae suspension at pH 6.5, the highest biomass recovery of 77% was obtained when 100 mg L−1 of FeCl3·6H2O (after 15 min) or 100 mg L−1 of Al2(SO4)3·18H2O (after 30 min) was added. However, microalgal recoveries significantly increased when FeCl3·6H2O or Al2(SO4)3·18H2O was used with the culture at pH 9.5. pH-Induced experiments showed that cultures adjusted at pH 10.5 had 36% higher biomass recovery compared to that in cultures at pH 8.5 after 2 h. The results of this study showed that cultures at higher pH (9.5) had a better microalgae recovery in all dewatering systems than cultures at lower pH (6.5).

Comparison of the Effectiveness of Natural Coagulant Performance on% BOD Removal and% COD Removal in Pharmaceutical Industry Waste

Waste treatment can be done in variousways. One of the methods that can be used isthe coagulation and flocculation method. Thecoagulant used can be either a chemicalcoagulant or a natural coagulant. Naturalcoagulants can be used in wastewatertreatment for % removal of BOD and %removal of COD. By using moringa seedcoagulant, it showed % removal of BOD of90.12% and % removal of COD in thepharmaceutical industry waste a maximum of71.23%. Through the use of tapioca starchcoagulants, % removal of BOD and CODwas 95.25% and 94.63%. The use of smallcrab chitosan coagulant showed % removalof both BOD and COD’s results was 32%and 31%.

Genetic Diversity and Quantification of Human Adenoviruses and JC Polyomaviruses in Wastewater Samples

Wastewater-based monitoring has been described as a non-invasive approach to assess virus distribution in a specific geographic area. In this study we assess the genetic diversity and concentration of human adenovirus (HAdV) and human polyomavirus JC (JCPyV) in wastewater samples in Rio de Janeiro, Brazil, during the Olympic Games, Rio 2016. Wastewater samples (50 mL) obtained from domestic and hospital sewages were concentrated by the skimmed milk flocculation method and processed using molecular tools. Quantitative polymerase chain reaction using the ABI PRISM 7500 Real Time TaqMan System and TaqMan Universal Master Mix II detected 18 HAdV and 17 JCPyV strains in 95% of those samples (18/19). A mean viral load of 8.6x105 genomic copies (GC)/L and 1.2x107 GC/L, was achieved for HAdV and JCPyV, respectively. Partial nucleotide sequencing using Sanger methodology revealed three HAdV species/ eight serotypes (HAdV B, D, D10, D17, D19, D22, F40 and F41) and seven genotypes/nine subtypes (JCPyV-1B, 2A, 3A, 3B, 4, 6, 7A, 8A and 8B). HAdV-D17 and -D22, as well as genotypes JCPyV-7 and -8, were detected for the first time in the country. The detection of previously undetected viruses in the region demonstrates the importance of our findings, adding data to the epidemiology of those viruses and corroborating the importance of environmental surveillance carried out from wastewater.

Research on Characteristic of Fe<sup>2+</sup>/S<sub>2</sub>O<sup>2-</sup><sub style="margin-left:-7px;">8</sub> Composite CaO Synergetic Conditioning for Municipal Sludge

For the problem as high energy consumption and sludge increment during the municipal sludge management process with advanced oxidation technology of sulfate radical, the Fe2+/S2O2-8 composite CaO reaction system was set up. Meanwhile, systematical studies had been carried out for coordinated conditioning of municipal concentrated sludge. The scientific process parameters were determined with the help of sludge capillary suction time, sewage sludge moisture content and other core indicators and the effect of traditional polyacrylamide flocculation method, Fenton method and activated persulfate method were compared. The results showed that in the neutral concentrated sludge conditioning, there were outstanding advantages for Fe2+/S2O2-8 composite CaO reaction system compared with Fenton, CPAM, and SO-4 methods and the optimal parameters for dosage were as follows: Fe2+/S2O2-8: 80 - 120 mg·g-1 DS, n(Fe2+):n(SPS) = 0.8:1, CaO: 200 mg·g-1 DS. To achieve similar performance index, the dosage of Fe2+ per ton for sludge could be reduced by 20%, the loss rate for iron in filtrate was 0.5%, dewatering of sludge by suction filtration was within 50 s and the moisture content for dewatering cake was 53.7%, which significantly improved the economy and practicability of SO-4 advanced oxidation technology, and the results were expected to form a useful supplement to the popularization and application of SO-4 advanced oxidation technology.

Removal Of Microplastics In The Industrial Wastewater Via The Fe-Based Coagulation Process

Currently, microplastics (MP) in the water environment is a global issue. Microplastics enter the natural environment through various sources such as domestic wastewater and industrial wastewater. The flocculation method - one of the simple and effective methods commonly used in wastewater treatment plants was used in this study to determine the removal efficiency of MPs in the industrial wastewater. The coagulation/flocculation experiments were carried on the Jartest model with the iron coagulant under different conditions. The wastewater was taken from the industrial park Song Than 1. The volume of the wastewater in each experiment was 500 mL with the MPs concentration of 78.4 mg/L which included 3 main forms with MP bead (322 different types / 0.5 L), MP fragment (131 different types / 0.5 L) and MP fiber (125 different types / 0.5 L). The optimal condition of microplastic removal (iron coagulant (FeCl3) = 600 mg/L, pH 8.6 – 8.8, settling time = 60 minutes, fast stirring of 300 rpm, slow stirring of 25 rpm, supporting-coagulant (CPAM) = 50 mg/L) was determined, corresponding with the MPs removal efficiency of 93.11% (MPs in effluent was 7.33 mg/L). The most common MPs categories collected after treatment were MP fragments (19 different types) and MP fibers (17 different types). MPs dimensions were mostly about 0.5 to 1 mm. Our result showed that the coagulation/flocculation process was an efficient method for the removal MPs in the industrial wastewater.

Rational Design of Pillared SnS/Ti3C2Tx MXene for Superior Lithium-Ion Storage.

MXenes have been widely explored in energy storage because of their extraordinary properties; however, the majority of research on their application was staged at multilayered MXenes or assisted by carbon materials. Scientifically speaking, the two most distinctive properties of MXenes are usually neglected, composed of large interlayer spacing and abundant surface chemistry, which distinguish MXenes from other two-dimensional materials. Herein, few-layered MXene (f-MXene) nanosheet powders can be easily prepared according to the modified solution-phase flocculation method, completely avoiding the restacking phenomenon of f-MXene nanosheets in preparation and oxidation issues during the storage process. Via further employing the solvothermal reaction and annealing treatment, we successfully constructed pillared SnS/Ti3C2Tx composites decorated with in situ formed TiO2 nanoparticles. In the composites, MXenes can play the role of a conductive network, a buffer matrix for volume expansion of SnS, while the active SnS nanoplates can fully deliver the advantage of high capacity and further induce interlayer engineering of Ti3C2Tx during cycling. As a result, the pillared SnS/Ti3C2Tx MXene composites exhibit obvious improvement in electrochemical performance. Interestingly, there is an apparent enhancement of capacity at succedent cycling, which can be ascribed to the "pillar effect" of Ti3C2Tx MXenes. The efforts and attempts made in this work can further broaden the development of pillared MXene composites.