Coagulant Addition Research Articles

Impact of choroid plexus coagulation on the success of endoscopic third ventriculostomy in children with hydrocephalus: a single-center retrospective observational cohort study.

Hydrocephalus is a common condition in childhood, often treated with ventriculoperitoneal shunts (VPS). Endoscopic third ventriculostomy (ETV) has emerged as an effective alternative, and the addition of choroid plexus coagulation (CPC) is believed to enhance its success, particularly in children under 6months. In this observational study, a retrospective analysis was conducted on 167 pediatric patients who underwent ETV, with and without CPC, at the Hospital da Restauração in Pernambuco. The primary outcome was to evaluate the success rates of ETV and ETV + CPC at immediate postoperative or outcome at discharge and 6-month follow-up. Statistical analyses, including chi-square, univariate, and multivariate logistic regression, were employed to assess correlations between dependent and independent variables. ETV + CPC showed a significantly higher success rate in the immediate postoperative period (91%) compared to ETV alone (75%) (p = 0.007). After 6months, success rates were similar for both groups (67% for ETV + CPC and 66% for ETV), with no significant difference (p = 0.855). Univariate and multivariate analyses revealed that the type of surgery (ETV + CPC vs. ETV) was a significant predictor of immediate postoperative success (OR 2.81, 95%CI 1.18-6.72, p = 0.020). Age and sex did not correlate significantly with surgical outcomes. The addition of CPC to ETV significantly enhances immediate postoperative success in young children with hydrocephalus. Although long-term outcomes equalized, these findings suggest that CPC can be a valuable adjunct in optimizing short-term results.

Rubber latex‐assisted improvement of nano‐zinc oxide dispersion in high density polyethylene matrix: A study on the effect of latex type and proportioning

AbstractHerein, the type of latex and its ratio to nano‐zinc oxide have been investigated for the effectiveness of latex‐assisted dispersion of nano‐zinc oxide. By analyzing the mixed state of latex and nano‐zinc oxide after the addition of coagulants, as well as physical and scanning electron microscope of corresponding composite materials, it was determined that natural rubber latex has the best auxiliary dispersion effect. Based on this result, the effect of the ratio of natural latex to zinc oxide nanoparticles was further investigated. Result showed that when the ratio of the two was too small, the nano‐zinc oxide in the rubber particles would cause the natural rubber latex to fail to solidify rapidly. When the ratio of the two was 2 : 1, the natural rubber latex rapidly solidify and encapsulate the nano‐zinc oxide. Eventually dispersed uniformly in the high density polyethylene matrix. Based on these results, the corresponding composites have a corrected notched impact strength of 142.6 kJ⋅m−2 and a tensile strength of 24.2 MPa. They also have excellent electrical insulation properties. These two properties are retained at a high rate after aging., This work further refines the latex‐assisted dispersion method and can improve the potential of the method for industrial applications.

Benchmarking of key performance factors in textile industry effluent treatment processes for enhanced environmental remediation

This article presents a comprehensive benchmarking analysis of merit performance factors in the Effluent Treatment Plants (ETP) of the textile industry. The study aims to identify and evaluate key factors that contribute to the efficient operation and performance of ETPs. The performance of ETP was analyzed by valuable data gained from figures of PH, Dissolved oxygen, Dissolved solids, Suspended solids, Density, COD and BOD. The technical trends showed the deviations in the working conditions of Effluent Treatment Plant by variation in temperature. This variation is achieved by varying the settling time of wastewater in the sedimentation tank during the working process. The required dosing, plant efficiency and economic factors were taken into account. The Plant efficiency was determined to be 83.5% at normal conditions of water entering at temperature of 30°C and pressure of 1 atm along with addition of coagulants and flocculants in the wastewater. While the efficiency of the ETP plant was calculated about 88% using a Compact photometer at elevated conditions of temperature such as > 45°C, while at other temperatures the efficiency decreases significantly due to several reasons. The operating time of water treatment was decreased due to the variations in temperature of wastewater while other conditions kept constant like pressure, flow rates of water and chemicals (Polyacrylamide and Polymeric Ferric Sulfate). The usage of coagulants and flocculants at optimum conditions has been discussed in this study.

Pathways and enhancement strategies for magnesium hardness removal in modified induced crystallization softening

Elevated levels of total hardness in drinking water can readily result in scaling, which poses a threat to both the safety of water quality and the convenience of its use. While there is a wealth of research on the removal of calcium hardness, there is a dearth of studies focusing on the removal of magnesium hardness. In light of this, the present study employs modified induced crystallization softening (MICS) to delineate the removal pathways and mechanisms of magnesium hardness, and to investigate viable methods for its enhancement and application. Our research has determined that magnesium hardness can be effectively removed from water through the MICS, with the dosage of softening agents (NaOH) being a significant factor that influences this removal, whereas the fixed bed height within the fluidized bed exerts minimal impact on the process. In the low-dose stage (less than 250 mg/L), when the pH is below 10.0, up to 20% of magnesium hardness can be removed, predominantly through the crystallization of (Ca0.936Mg0.064)CO3. As the dosage increases to the moderate stage (250–400 mg/L), the conversion of excess bicarbonate (HCO3−) to carbonate (CO32−) in the water hinders further removal of magnesium hardness. In the high-dose stage (exceeding 400 mg/L), when the pH rises above 10.5, the removal rate of magnesium hardness can be enhanced to over 75%, with the crystallization of Mg(OH)2 being the primary removal mechanism. Density functional theory calculations, along with molecular dynamics simulations of cohesive energy and bond energy, substantiate the feasibility of the identified magnesium removal pathways. The addition of coagulants (FeCl3) and an decrease in the up-flow velocity can further augment the removal efficiency of magnesium hardness by promoting the crystallinity of Mg(OH)2 during the high-dose stage (exceeding 400 mg/L). In practical engineering applications, the strategic control of softening agent dosages enables the achievement of varying levels of magnesium hardness removal, tailored to specific water quality requirements.

Improving yield, functional properties, and aroma profile of rice bran protein through innovative extraction and precipitation methods

Rice bran is a milling byproduct and rice bran protein (RBP) is a promising source of plant-based protein. This study investigated the impact of alkaline and acid extractions followed by isoelectric point (IEP) and heat coagulation precipitations on the quality and functionalities of RBP. Alkaline extraction, followed by IEP and heat coagulation, showed the highest protein recovery of 48.77%, which is double that of conventional alkaline extraction and IEP. The FTIR data showed that β-sheet and α-helix content reduced; however, random coil and β-turn increased by acid and heat addition. Addition of heat coagulation to IEP after alkaline extraction increased solubility from 62.94% to 94.74%. However, the emulsification and surface hydrophobicity were decreased during heat and acid-assisted extraction. The in-vitro digestibility was the highest at 83.57% in alkaline-acid extraction, followed by heat and IEP. The aroma profile of RBP shows a complex mixture of ethanol-2-butoxy, 2-methyl-4-vinyl-phenol, 2,4—heptagonal, (E,E)-, Undecane, and 5-methyl to form a typical flavor with waxy and rancid undernotes. The total amount of volatile compounds in conventional extraction was 1.97 μg/g, while alkaline-acid extraction with IEP had only 0.87 μg/g. The RBP from alkaline-acid extraction with IEP showed the least volatile compounds and most neutral proteins.

Multi-component wastewater from finely dispersed impurities treatment intensification

The article deals with the intensification of flocculation wastewater treatment from finely dispersed suspended dust particles that are formed in the foundry shop at machine-building productions. The dependence of the floc sedimentation rate and wastewater clarification on solid phase concentration and flocculant flow rate was experimentally researched using model wastewater created by mixing dust and water. The multicomponent impurities of ionic flocculants on the aggregation process impact were experimentally proven, and anionic and cationic flocculants combination high efficiency was shown. The optimal parameters for the wastewater treatment process were established. The best flocculating effect and minimum flocculant consumption were observed at a solid phase concentration of 8-14 g/l. It was established that the most effective aggregate formation process is observed when two flocculants’ types are used simultaneously: anionic A-19 and cationic K-7, not each type separately. Flocculant flow rate experimental and calculated dependences for the wastewater treatment process depending on solid phase concentration and floc sedimentation speed necessary for effective sedimentation have been established. A technological scheme for wastewater treatment from suspended dust impurities that are formed in foundry shop at machine-building enterprise has been developed. The scheme includes: wastewater flocculation; water clarification in a sedimentation tank; and water deironing by aeration with coagulant addition and further filtration. It is proposed to use purified water in enterprise technological cycle that helps to reduce tap water consumption.

Extended survival of 9- and 10-gene-edited pig heart xenografts with ischemia minimization and CD154 costimulation blockade-based immunosuppression

BackgroundXenotransplantation has made significant advances recently using pigs genetically engineered to remove carbohydrate antigens, either alone or with addition of various human complement, coagulation, and anti-inflammatory ‘transgenes’. Here we evaluated results associated with gene-edited (GE) pig hearts transplanted in baboons using an established costimulation-based immunosuppressive regimen and a cold-perfused graft preservation technique. MethodsEight baboons received heterotopic abdominal heart transplants from 3-GE (GalKO.β4GalNT2KO.hCD55, n=3), 9-GE (GalKO.β4GalNT2KO.GHRKO.hCD46.hCD55. TBM.EPCR.hCD47.HO-1, n=3) or 10-G (9-GE+CMAHKO, n=2) pigs using Steen’s cold continuous perfusion for ischemia minimization. Immunosuppression (IS) included induction with anti-thymocyte globulin and αCD20, ongoing αCD154, MMF, and tapered corticosteroid. ResultsAll three 3-GE grafts functioned well initially, but failed within 5 days. One 9-GE graft was lost intraoperatively due to a technical issue and another was lost at POD 13 due to antibody mediated rejection (AMR) in a baboon with a strongly positive pre-operative cross-match. One 10-GE heart failed at POD113 with combined cellular and antibody mediated rejection. One 9-GE and one 10-GE hearts had preserved graft function with normal myocardium on protocol biopsies, but exhibited slowly progressive graft hypertrophy until elective necropsy at POD393 and 243 respectively. Elevated levels of IL-6, MCP-1, C-reactive protein, and human thrombomodulin were variably associated with conditioning, the transplant procedure, and clinically significant postoperative events. ConclusionRelative to reference genetics without thrombo-regulatory and anti-inflammatory gene expression, 9- or 10-GE pig hearts exhibit promising performance in the context of a clinically applicable regimen including ischemia minimization and αCD154-based IS, justifying further evaluation in an orthotopic model.

Effectiveness of advanced oxidation process for the pretreatment of mixed agrofood industrial wastewater from Nablus City, Palestine

ABSTRACT Food processing industries generate complex effluent with high levels of organic and inorganic contaminants. Without proper treatment, significant operational, environmental, and public health issues may arise. This study aimed to assess the Fenton reaction’s efficacy as an advanced oxidation process (AOP), to treat mixed dairy and slaughterhouse effluent from Nablus city. Bench-scale tests showed inadequate results (45.2% COD removal) because of high pollution levels (COD: 15400 -18,100 mg L−1). Further tests have combined the Fenton process with three pre-treatment methods: (A) coagulant addition, (B) settling, and (C) flocculent application. Fenton’s process with flocculent achieved significant removal of organic (88.4% COD; 84.1% TKN) and inorganic (91.0% TSS; 62.4% TS) contaminants under optimised conditions (H2O2/COD ratio 2:1, H2O2/Fe + 2 ratio 10:1, pH = 3). Treated wastewater from trial (C) let meeting local regulatory standards with COD levels below 2,000 mg/l.

Low-carbon emitting Fe-cycle recovery of battery-grade FePO4 from biogas slurry for Li-battery application

Under the background of carbon peaking and carbon neutrality in China, anaerobic digestion of sludge to produce methane was an important way to recover biomass energy. But plenty of as-generated biogas slurry (BS) with high P concentration was valuable and difficult to dispose. Here, this work proposed a low-carbon emitting Fe-cycle strategy to recover battery-grade FePO4 from BS. At pH=1.0, the P-leaching rate of Fe-sludge (42.93 ± 1.49 mg g−1) generated by polymerized ferrous sulfate (an inorganic polymer coagulant) addition into BS was 93.46 ± 3.56% and high-purity FePO4 (99.0%) could further be obtained by Fe3+ supplement and pH adjustment (pH=2.0). The contents of all elements in recovered FePO4 product fully complied with the battery grade of national industry standard of China (HG/T 4701-2021). After battery-grade FePO4 precipitate separation, recovery solution (RS) with remaining Fe3+ was reutilized to remove 88.05 ± 1.77% of P when mixed with BS wit RS/BS ratio of 2:1, thus achieving a Fe cycle utilization. Meanwhile, the recovery cost of 5.42 $/kg P and CO2 emissions of 80.83 kg/kg P were lower than those of current FePO4 industrial production (14.60 $/kg P and 110.60 kg/kg P). Finally, the LiFePO4/C cathode material based on recovered FePO4 from BS exhibited stable discharge specific capacity of 84.6–100.2 mAh/g during 100 charge–discharge cycles. In general, this study successfully manifested the feasibility of novel Fe-cycle battery-grade FePO4 recovery strategy from wastewater, paving a viable low-carbon emitting pathway for future Li-battery manufacture industry.

Full factorial design of the effects of coagulants and processing variables on the physicochemical quality and texture profile analysis of kenaf seed tofu

Aim: Kenaf (Hibiscus cannabinus) is an herbaceous plant of economic significance, the seed is rich in essential nutrients and has the potential for the production of protein-based products. This study investigated the holistic effects of coagulants, kenaf seed-to-water ratio for extraction, and temperature of addition of coagulant on the physicochemical and texture quality of kenaf seed tofu. Methods: Randomised full factorial design was used to obtain different formulations of kenaf seed tofu production under 4 factors at different levels. Results: The main factors of coagulant types, seed-to-water ratio and temperature of addition of coagulant significantly affected the yield, pH, crude protein, crude fat, lightness, yellowness and cohesiveness of the kenaf seed tofu while the redness of the tofu was significantly affected by the coagulant types only. However, the hardness, chewiness and springiness of the tofu were affected by coagulant types and concentrations. Additionally, the 2-way interactions significantly affected the texture profile of the tofu. Though, the 3-way and 4-way interactions have no significant effect on the texture characteristics of the kenaf seed tofu. Conclusions: The tofu made with aluminium potassium salt at concentrations of 0.50 g/100 mL and 1.00 g/100 mL, and 80°C temperature of addition of coagulant formed the highest yield of 71.22 g/100 g and 77.57 g/100 g, respectively. This study also found that aluminium potassium salt and glucono-delta-lactone, with the use of 1:3 seed-to-water ratio and 70°C or 80°C temperature of addition of coagulant were better in terms of hardness and chewiness.

The removal of microplastics from reverse osmosis wastewater by coagulation

Wastewater treatment plants (WWTPs) are major sources of microplastic (MP) discharge into water bodies, leading to plastic pollution in the environment and negative effects on aquatic ecosystems. Research is increasingly being focused on MP removal from wastewater, as their presence in freshwater environments, and associated risks, are matters of growing concern. Eliminating MPs from wastewater is a significant challenge for WWTPs, and mitigation actions are required to develop and improve removal treatments. Coagulation has been shown to have high removal efficiency for suspended particles, including MPs. This process involves the addition of coagulants, such as aluminum or iron salts that together with the MPs form larger flocs, facilitating their removal by settling or flotation. Our study evaluated the coagulation process, aiming to improve MP removal from wastewater generated from reverse osmosis (RO) concentrate, backwash microfiltration (MF), and cleaning chemicals for membranes operated by MF and RO processes in industrial water supply facilities. More than 1000 MP particles, predominantly polymers with polyethylene (PE), polypropylene (PP), and polystyrene (PS) were identified as being influenced by the current process. We used polyaluminum chloride (PAC) as chemical coagulant to evaluate MP removal during batch experiments (jar test). Our coagulation process achieved higher efficiencies for microplastic removal than conventional biological treatment processes at an optimal PAC dose and pH. Remarkable results were obtained, with more than 90% of MPs being removed. Our findings indicate that chemical coagulation is effective for removing MPs, and that the process could be optimized by selecting an appropriate coagulant and pH.

Pengaruh Konsentrasi Koagulan Terhadap Proses Pengolahan Air Di PDAM Surya Sembada Kota Surabaya

Coagulation is one of the processes of water treatment by the addition of chemicals, the purpose of which is to bind particles like particles or dissolve so that they clump. Coagulation concentration definitely affects the coagulation process carried out. In addition, the addition of coagulation also affects the water produced for distribution. Testing of the impact of coagulant concentrations on raw water treatment processes has been carried out on the PDAM Surya Sembada Surabaya. The use of laboratory testing methods is done to see the water quality when using different coagulants. The results of the analysis obtained that the difference in the concentration of coagulants has an influence on the process of water treatment, this is due to several factors that support the existence of variation in the use of the coagulation concentration.

Comparing the effects of Al-based coagulants in waste activated sludge anaerobic digestion: Methane yield, kinetics and sludge implications

Due to its effectiveness and ease of application, the process of flocculation and coagulation is often used for pollution removal in wastewater treatment. Most of these coagulants precipitate and accumulate in waste activated sludge (WAS), and could negatively affect sludge treatments, as observed for anaerobic digestion. Nowadays, wastewater treatment plants (WWTPs) are widely discussed because of the current paradigm shift from linear to circular economy, and the treatments performed at the facility should be planned to avoid or reduce adverse effects on other processes. The aim of this study was to compare the impact of poly aluminum chloride (PAC) and aluminum sulfate (AS) on WAS anaerobic digestion, by feeding replicate serum reactors with different levels of coagulant (5, 10 and 20 mg Al/g TS). Reactors without the addition of any coagulants represented the control group. Results revealed that Al-based coagulants inhibited methane production, which decreased as the coagulant addition increased. The inhibition was much more severe in AS-conditioned reactors, showing average reductions in methane yield from 14.4 to 31.7%, compared to the control (167.76 ± 1.88 mL CH4/g VS). Analytical analysis, FTIR and SEM investigations revealed that the addition of coagulants affected the initial conditions of the anaerobic reactors, penalizing the solubilization, hydrolysis and acidogenesis phases. Furthermore, the massive formation of H2S in AS-conditioned reactors played a key role in the suppression of methane phase. On the other hand, the use of coagulant can promote the accumulation and recovery of nutrient in WAS, especially in terms of phosphorus. Our findings will expand research knowledge in this field and guide stakeholders in the choice of coagulants at full scale plant. Future research should focus on reducing the effect of coagulants on methane production by modifying or testing new types of flocculants.

Effect of FeCl3 concentration in chemically enhanced primary treatment on the performance of a conventional wastewater treatment plant. A case study

The effect of coagulant dosage in a chemically enhanced primary treatment (CEPT) on the performance of a conventional wastewater treatment plant (WWTP) has been investigated. Lab-scale experiments simulations were carried out in order to evaluate the effect of coagulant addition on the primary settling performance. In these experiments, FeCl3 was used as coagulant. Later, the WWTP was theoretically simulated using a commercial software (WEST®) to evaluate the effect of coagulation/flocculation on the global system, based on the results obtained at lab-scale. According to these results, the CEPT modifies the organic matter balance in the WWTP, decreasing the contribution of readily (SS) and slowly (XS) biodegradable fractions of COD to the aerobic biological process up to 27.3% and 80.8%, respectively, for a dosage of FeCl3 of 24 mg L−1. Consequently, total suspended solids in the aerobic reactor and the secondary purged sludge decreased up to 33% and 13%, respectively. However, the influence on effluent quality was negligible. On the contrary, suspended solids concentration in the sludge to be treated by anaerobic digestion increased, mainly regarding the Ss and Xs fractions, which caused an 8.1% increase in biogas production potential, with approximately 60% of CH4 concentration.

Controlling membrane fouling of nanofiltration using poly-aluminum chloride and Moringa oleifera coagulants

Membrane fouling control during nanofiltration (NF) of contaminated water sources is critical to establishing a cost-efficient advanced drinking water treatment system. This study aimed to evaluate the effect of pre-coagulation using Moringa oleifera (MO) or poly-aluminum chloride (PACl) coagulant on membrane fouling mitigation and final water quality during NF treatment of lake water. This study used four pre-coagulation methods: (i) full coagulation: coagulation-flocculation-sedimentation, (ii) coagulation and flocculation, (iii) rapid mixing alone, and (iv) without coagulant addition. The full coagulation with PACl or MO before NF treatment mitigated membrane fouling, and the optimum PACl or MO coagulant doses achieved the lowest membrane fouling. PACl or MO pre-coagulation with rapid mixing also mitigated membrane fouling, which suggested the potential use of inline coagulation. Turbidity in the coagulated water was the best indicator to predict the level of NF membrane fouling; thus, turbidity in the pre-coagulated water can be utilized to control NF membrane fouling. Regardless of the types of pre-coagulation methods, turbidity and dissolved organic matter concentrations in the NF permeate were equivalent. The results suggest that nanofiltration coupled with inline pre-coagulation can provide high-quality water.

Development of a Hybrid Technological Scheme for the Treatment of Anaerobically Fermented Sludge (Digestat) of Wastewater of the Food Industry

The issue of dewatering and disposal of sewage sludge is one of the most urgent due to the acute shortage of land resources, the negative ecological burden on water resources, soils and the atmosphere of these sludges in case of their accumulation without proper treatment. Anaerobic stabilization of food production wastewater sludge is one of the most widespread methods of processing this type of sludge due to the possibility of obtaining an important energy resource – biogas. The sludge obtained after anaerobic stabilization in methane tanks is called digestate, and it also needs treatment and further disposal. Digestate can be used as a fertilizer if sanitary and hygienic requirements are met. The development of a technological scheme for processing wastewater digestate is a complex issue that does not have one correct solution. A hybrid technological process for processing wastewater digestate of the food industry is proposed on the basis of experimental studies. Experimental studies include dewatering anaerobically stabilized sludge on a multi-disc dehydrator using dilution of the sludge itself due to its significant viscosity, addition of coagulant and flocculant. Cake with a moisture content of about 65–80% can be transported and used as fertilizer for agriculture. The separated filtrate from the digestate according to the technological scheme is proposed to be purified on two stages of membranes. The efficiency of cleaning the liquid fraction of the digestate on a two-stage membrane installation according to two variants showed the following results: variant 1 (VSEP + RO) – 95%, variant 2 (ZI + RO1 + RO2) – 94%. The VSEP system uses a hermetic RO membrane, so a two-pass membrane process (VSEP+RO) is suitable to achieve the end goal (permeate obtained can be reused), while a ZI membrane requires a three-pass membrane process to achieve the same goal. The achieved parameters make it possible to use the obtained permeate for the production needs of the enterprise or in the technological scheme of the digestate processing itself for dilution of the sediment or for the preparation of reagent solutions. The resulting products (cake and concentrates after membranes) can be used as fertilizers.

Evaluation of Wastewater Coagulation/Flocculation with Chitosan from Shrimp Exoskeletons Waste and Aluminum Sulfate

Intensive use of water, growing cities, and lack of wastewater treatment are some factors increasing hydric stress worldwide. Coagulation/flocculation is one of the preferred treatments for wastewater. However, aluminum salts are traditionally used in this process. This coagulant has a high environmental footprint and residual aluminum in wastewater is a public health concern. The preparation and use of chitosan as a coagulant aid in coagulation/flocculation with aluminum sulfate were investigated. The ef fect of the order of addition of coagulants (aluminum sulfate followed by chitosan, or chitosan followed by aluminum sulfate), dose of the coagulants, pH, and slow mixing velocity for flocculation were studied. It was found that the removal of total suspended solids (TSS) with aluminum sulfate was relatively unaf fected by pH (aluminum sulfate dose of 100 mg L-1 at pH of 5 units achieved 94% removal of TSS and at pH of 8.2 units 89% removal of TSS), whereas with chitosan was highly af fected (chitosan dose of 180 mg L-1 at pH of 4 units achieved 96% removal of TSS and at pH of 8.2 units 25% removal of TSS). In the coagulation/flocculation experiments where both coagulants were used, it was found that the order of coagulant addition and pH of wastewater have a statistically significant ef fect (P-value < 0.05) on the removal of TSS. Higher removal of TSS was achieved when aluminum sulfate was added followed by chitosan at a wastewater pH of 5 units. Chitosan can be ef fectively used to reduce the use of aluminum salts in wastewater treatment. However, it is necessary to optimize the preparation of this coagulant and investigate other factors, such as variation in the wastewater quality, that can af fect the robustness of the process.

Differently charged polyacrylamides (PAMs) significantly affect adsorption affinity and associated floc growth behaviors during ballasted flocculation: Performance and mechanism

Various organic polymers have been widely used to provide inter-particle bridging between microsand and microflocs for producing ballasted floc aggregates during ballasted flocculation. However, it is not yet clear how differently charged polymers will determine predominant mechanisms of ballasted floc growth at diverse coagulant dosages. In this study, three representative aluminum sulfate (AS) coagulant dosages (where microfloc aggregates formed after coagulant addition possessed negative, zero and positive zeta potentials, respectively) were prearranged, and then the role of cationic, anionic and nonionic polyacrylamides (PAMs) in ballasted flocculation of clay suspensions was comparatively evaluated at each AS dosage. As expected, the temporal evolution of floc average size at stages of ballasted floc maturation and regrowth (following breakage) was dependent upon both AS coagulant dosage and PAM selection. Also, the selection of differently charged PAMs produced maturated floc aggregates with different shear-resistant and recovery abilities at a fixed AS dosage, presumably owing to the predominant mechanism of ballasted floc growth. Differently from the removal efficiency of water turbidity after sedimentation, the involvement of nonionic PAM (rather than the case of “without adding PAM”) gave rise to the lowest removal percentage of UV254 at the same AS dosages. This finding was probably attributed to the role of possible flocculation mechanism(s) in the transformation of dissolved humic acid (HA) complexes into insoluble HA composites at the maturation stage. Based on the experimental results, a conceptual model of ballasted floc growth process induced by differently charged polymers was proposed to vividly explore the possible floc-growth mechanism (such as charge neutralization, polymer bridging, and/or electrostatic patch) occurring for each combination of coagulant dosage and PAM type. This research may contribute to gaining a deep insight into the combined effects of coagulant dosage and differently charged polymer selection on the interaction between polymer-enhanced floc cohesion and ballasted floc formation.

Synergistic Effects of Ionizing Radiation Process in the Integrated Coagulation–Sedimentation, Fenton Oxidation, and Biological Process for Treatment of Leachate Wastewater

This study evaluated the feasibility of ionizing radiation combined with coagulation–sedimentation and Fenton oxidation as a treatment method for landfill leachate. The experiments revealed a positive correlation between pollutant removal efficiency and increased ionizing radiation intensity. Remarkable pollutant removal efficiencies were achieved under ionizing radiation at 50 kGy, with a maximum of 27% removal of total organic carbon (TOC), 61% removal of total nitrogen, 51% removal of total phosphorus, and an impressive 93% removal of NO3−-N. With the addition of coagulation–sedimentation and Fenton oxidation, the treatment efficiency further increased by 33% nitrogen, 18% SCOD, and 8% phosphate. The most significant observation from the study was that for all the different treatment methods, the results were always better for leachate samples treated with ionizing radiation than for the untreated samples. Subsequently, biological treatment was applied as a post-treatment method to remove residual organic carbon and nitrogen, which found that the best removal efficiencies were only for the low salt concentration (0.5%) and the removal decreased with increasing salt concentration. These experimental results conclusively demonstrated that when treating leachate wastewater, it was more appropriate to employ physicochemical methods rather than a biological treatment, primarily due to the high salt concentration present.

Review of Advanced Water Treatment for Removal of Nanoplastic Pollution

Drinking water is a very important basic need for humans. One of the detected drinking water pollution that greatly affects the quality is the content of nanoplastics. In aquatic ecosystems, nanoplastics are materials that cannot be decomposed. Through this brief review, the efficiency of removing nanoplastics using various water treatment methods will be reviewed. Some of the treatment methods reviewed are nanoplastic removal using filtration, adsorption, coagulant and flocculant addition, and CFS (Coagulation/Flocculation Sedimentation). The research method used is a literature review related to drinking water treatment to eliminate pollution by nanoplastics. The conclusion from the literature review is that the process of treating drinking water by filtration with the addition of coagulants is the most efficient treatment for removing pollution by nanoplastics, reaching 99.9%.