Low Removal Rate Research Articles

Evaluation of MC-LR Removal by Sodium Hypochlorite Disinfection as Best Available Technology (BAT) for Algal Toxin Removal

Harmful cyanobacteria produce various toxic substances, among which microcystin is the most commonly detected toxin in water resources, with microcystin-LR(MC-LR) known to be the most toxic. For the removal of microcystin, sodium hypochlorite(NaOCl) disinfection is recognized as an effective best available technology(BAT) in water treatment facilities for MC-LR removal, within limits that minimize the formation of disinfection by-products. However, chlorine disinfection of microcystin is affected by various factors, including temperature and pH, with environmental factors such as the presence of organic matter in raw water potentially influencing the efficiency of microcystin removal. In this study, raw water was collected from the Nakdong River, and Intracellular Organic Matter(IOM) was extracted from algal cells. NaOCl was then added to both the IOM raw water and DI water to assess the chlorine disinfection rate of MC-LR removal and to analyze the pseudo-first-order reaction kinetics, evaluating the impact of organic matter in raw water on MC-LR chlorination. The results showed that the MC-LR removal rate in IOM by chlorine disinfection was a maximum of 17%, while the MC-LR removal in deionized water reached up to 99%. The pseudo-first-order reaction rate constants were 3.99×10<sup>-5</sup>s<sup>-1</sup> and 9.11×10<sup>-4</sup>s<sup>-1</sup> for IOM and deionized water, respectively, indicating that MC-LR removal in IOM was slower and had a lower removal rate compared to that in deionized water. This study demonstrates that chlorine disinfection is suitable as the BAT for algal toxin removal and highlights the need to reduce the amount of organic matter through pre-treatment before chlorine disinfection.

A Single-Center Retrospective Study on the Clinical Outcomes of TightRope Fixation Versus Syndesmotic Screw Fixation in the Management of Acute Traumatic Ankle Syndesmotic Injuries.

Background Ankle fractures are one of the most commonpresentations in orthopaedic surgery and represent the third most frequent musculoskeletal injury in the elderly population. Syndesmotic injuries can be associated with ankle fractures, and surgical intervention is critical in these injuries to restore stability and prevent long-term disability. Traditionally, syndesmotic screw fixation has been the standard treatment for acute traumatic syndesmotic injuries, but controversies regarding this fixation method remain. Over recent years, the TightRope system (Arthrex,Florida, US)has gained popularity as a dynamic alternative, offering the advantage of restoring anatomical function while maintaining reduction. The optimal surgical fixation method for managing syndesmotic injuries remains a topic of ongoing debate withinorthopaedic practice. Therefore, this study aims to compare the clinical outcomes of these two fixation methods to provide further guidance on their use in managing acute traumatic syndesmotic injuries. Methods A retrospective cohort study was performed for all patients with ankle syndesmotic injuries who underwent surgical fixation using either TightRope devices or syndesmotic screws at Buckinghamshire Healthcare NHS Trust between June 2020 and June 2023, identified through the BlueSpier electronic record system (Bluespier, Droitwich, United Kingdom). Data on demographics and surgical details were extracted from electronic medical recordswhile radiographic images were systematically reviewed to confirm eligibility for inclusion. Clinic letters were also reviewed for complications and reasons for metalwork removal. Results A total of 217 patients met the eligibility criteria for this study, with 132 (61%) females and 85 (39%) males, aged between 13 and 93 years (mean age: 49 years). Of the cohort, 28 (13%) underwent syndesmotic fixation with TightRope deviceswhile 189 (87%) were treated with syndesmotic screws. Metalwork removal was required in 11% of TightRope cases (3 patients) and 28% of syndesmotic screw cases (52 patients). The most commonreason for metalwork removal in our study cohort was for broken or loosened screw(s), followed by discomfortand patient preferences. The metalwork removal rates in our study cohort are consistent with those reported in the current literature. Conclusion In conclusion, our study found that the use of TightRope devices is associated with lower removal rates in comparison to syndesmotic screws. This finding is consistent with those reported in the current literature. The most commondocumented reason for metalwork removal in our study cohort was due to screw breakage or loosening. Although emerging evidence suggests that routine removal of syndesmotic screws may not be necessary, given the lack of consensus regarding the routine removal of syndesmotic screws, decisions for metalwork removal should be tailored by clinical judgement and individual patient needs. Despite its limitations, this study contributes valuable insights into the outcomes and metalwork removal rates associated with syndesmotic fixation methods in the management of acute ankle fractures with syndesmotic injuries.

Low Complication Rates in Olecranon Fracture Fixation With Dual Plating.

Most olecranon fractures are intra-articular, affecting the extensor mechanism of the elbow, and are treated surgically with dorsal plate fixation or tension band. Due to shortcomings of dorsal plates related to prominence, insufficient fixation of sagittal fracture lines, and difficulty matching proximal ulna dorsal angulation (PUDA), dual medial and lateral plating (DP) has been developed. We hypothesized that olecranon fractures treated with DP would have low complication rates and low incidence of hardware removal compared with those treated with traditional methods of fixation. The database of a single institution was reviewed for the period January 2017 to April 2023 for adults with olecranon fractures receiving DP fixation. Open fractures, fracture dislocations, previous elbow injuries, and pathologic fractures were excluded. Demographics, pre- and postoperative imaging, reoperations, and range of motion were collected. PUDA and varus angulation measurements, intra-articular step off, and fracture distraction were recorded. A total of 42 fractures in 41 patients were reviewed. Mean follow-up was 8.7 months (range, 3-36 months). One patient reported symptomatic hardware at 6 weeks that had resolved by 3 months, and 1 reported persistent symptomatic hardware not bothersome enough to warrant removal. Five patients (11.9%) had at least 1 postoperative complication. The hardware removal rate was 2.4%. DP for olecranon fractures represents a valuable strategy in fracture treatment. We report a low hardware removal rate of 2.4%, with removal being done for infection, not symptomatic hardware. DP provides a reliable method of fixation, helps re-create native anatomy, and has a low complication rate compared with standard dorsal plating. [Orthopedics. 202x;4x(x):xx-xx.].

Acute Lisfranc injury management.

Lisfranc injuries were previously described as fracture-dislocations of the tarsometatarsal joints. With advancements in modern imaging, subtle Lisfranc injuries are now more frequently recognized, revealing that their true incidence is much higher than previously thought. Injury patterns can vary widely in severity and anatomy. Early diagnosis and treatment are essential to achieve good outcomes. The original classification systems were anatomy-based, and limited as tools for guiding treatment. The current review, using the best available evidence, instead introduces a stability-based classification system, with weightbearing radiographs and CT serving as key diagnostic tools. Stable injuries generally have good outcomes with nonoperative management, most reliably treated with immobilization and non-weightbearing for six weeks. Displaced or comminuted injuries require surgical intervention, with open reduction and internal fixation (ORIF) being the most common approach, with a consensus towards bridge plating. While ORIF generally achieves satisfactory results, its effectiveness can vary, particularly in high-energy injuries. Primary arthrodesis remains niche for the treatment of acute injuries, but may offer benefits such as lower rates of post-traumatic arthritis and hardware removal. Novel fixation techniques, including suture button fixation, aim to provide flexible stabilization, which theoretically could improve midfoot biomechanics and reduce complications. Early findings suggest promising functional outcomes, but further studies are required to validate this method compared with established techniques. Future research should focus on refining stability-based classification systems, validation of weightbearing CT, improving rehabilitation protocols, and optimizing surgical techniques for various injury patterns to ultimately enhance patient outcomes.

Assessment of Cyanotoxins Removal Efficiency Using a Simulated Drinking Water Treatment Process for Downstream Source Water of the Nakdong River

Objectives : This study aims to evaluate the removal rates of nine cyanotoxins produced by cyanobacteria using a laboratory-scale simulated drinking water treatment process (DWTP), providing useful data for DWTP operations during algal blooms.Methods : A lab-scale simulated DWTP was used to evaluate the removal rates of nine cyanotoxins under typical operating conditions, including specific chemical dosages and contact times. The study employed chlorine and ozone, as well as powdered activated carbon (PAC) and biological activated carbon (BAC).Results and Discussion : According to the experimental results of removal efficiency for chlorination and ozonation, microcystin-LR (MC-LR), MC-RR, MC-LA, MC-LF, MC-LY, MC-YR, cylindrospermopsin (CYN), and nodularin (NOD) were effectively removed within the typical ranges of pre- and post-chlorine and pre- and post-ozone concentrations in the DWTP. However, anatoxin-a (ANA) exhibited a significantly lower removal efficiency. The evaluation of removal efficiency for PAC treatment indicated that MC-LA, MC-LF, and MC-LY had low removal rates. In contrast, the other six cyanotoxins achieved over 50% removal when PAC concentrations were above 25 mg/L and contact times exceeded 30 minutes. The evaluation of removal rate for BAC treatment showed that under conditions with an empty bed contact time (EBCT) of more than 5 minutes, over 70% of the nine cyanotoxins were removed. When the EBCT exceeded 2 minutes, removal rates reached between 95% and 100%. In the BAC process, the removal of MC-RR was primarily facilitated by the biodegradation, while the removal of CYN was mainly achieved through adsorption.Conclusion : Due to climate change, the bloom periods of various cyanobacteria in domestic water sources are gradually increasing, resulting in a rising trend in both the frequency and concentration of detected cyanotoxins. This study evaluated the removal efficiency of various cyanotoxins in DWTPs, focusing on chlorine/ozone treatment (oxidation), PAC treatment (adsorption), and BAC (adsorption and biodegradation). The different DWTPs at the facility act as multiple barriers, effectively removing cyanotoxins upon their introduction.

How Well Do Endemic Wetland Plant Species Perform in Water Purification?

Rising anthropogenic-induced nutrient enrichment of surface waters is of great concern globally as it jeopardizes the ecological integrity and functioning of freshwater ecosystems. Floating wetlands have been successfully used to treat nutrient enriched wastewater in developing nations, and provide additional co-benefits. We aimed to quantify the nutrient removal efficiency of high-potential, endemic wetland species on floating wetlands in different conditions and to understand whether the nutrient uptake process was characterised by key plant functional traits. Two experiments were run under Mediterranean-climate conditions of the Western Cape of South Africa: (1) a closed, oligotrophic mesocosm experiment representing local conditions and (2) a real-life (in-situ) eutrophic application. The mesocosm experiment conducted under oligotrophic local conditions yielded low nitrate, phosphate and ammonium removal rates (34.8–35.2 mgNO3-Nm− 2.d− 1, 10.4–10.7 mgPO4-Pm− 2.d− 1 and 3.6–3.8 mgNH4-Nm−2.d− 1) in comparison to other floating wetland studies globally, yet high removal efficiencies (> 90%). However the eutrophic in-situ experiment demonstrated the potential for these same endemic plants to remove up to 312 g.m− 2 of nitrogen and 47 g.m− 2 of phosphorus per year– which is relatively high compared to similar global research. Cyperus textilis had the highest daily nutrient uptake and content followed by Prionium serratum and Juncus lomatophyllus, while J. lomatophyllus had the greatest nutrient uptake efficiency. Two of the three species (C. textilis and P. serratum) stored significantly more total nutrients in their shoot tissue compared to their root tissue, suggesting that the permanent removal of nutrients from the system is possible through shoot harvesting. Floating wetlands planted with endemic plant species have the potential to remove nutrients effectively and sustainably from eutrophic water and can thus be implemented as low-cost nature-based solutions to mitigate pollution of lentic systems.

Selective oxidation of nitrogenous heterocyclic compounds by heat/peroxymonosulfate in phenol-rich wastewater

In phenol-rich wastewater, such as coking wastewater, due to the high reactivity of phenol to various reactive oxygen species, it is difficult to selectively oxidize pollutants having lower biodegradability and higher toxicity than phenol. As one kind of such pollutants in coking wastewater, some nitrogenous heterocyclic compounds (NHCs) are more difficult to be removed by SO4•- or HO• than phenol, but this study found that NHCs (quinoline, isoquinoline, and pyridine) can be selectively removed by peroxymonosulfate (PMS) direct oxidation in the presence of 10 mM phenol under thermal condition. The selective oxidation of NHCs needs a suitable pH range (4 < constant pH < 9) because protonated state of NHCs (pH < 4) is unfavorable to their oxidation and high pH would improve the extra PMS consumption by phenol. Under the conditions benefiting the removal of NHCs in heat/PMS system, there was no generation of SO4•- and HO•. Being treated by 60 °C/PMS for 60 min, the biodegradability (BOD5/COD) of real coking wastewater (RCW) was improved from 0.21 to 0.44 with low removal rate of phenols (about 10 %). Quinoline and indole, as the two typical NHCs in the studied RCW, their removal rates can be up to 45 % and 85 %, respectively. Thus, heat/PMS pretreatment is a potential good way to selectively remove high toxic pollutants in phenol-rich wastewater.

Significant effects of rural wastewater treatment plants in reducing microplastic pollution: A perspective from China's southwest area

Sewage systems are a major source for microplastics in riverine exports to oceans. Urban areas are generally considered hotspots for microplastic discharge, whereas emissions from rural areas remain largely understudied. Hence, this study investigated the abundance, characteristics, and polymer types of microplastics in rural wastewater treatment plants (WWTPs) in Guiyang and estimated the annual microplastic emissions of China based on sewage discharge. The influent abundance of microplastics was 3.8–8.2 items/L, the effluent abundance was 3.1–5.9 items/L, with a lower removal rate of 14.4 %−54.6 %, which might be influenced by lower operating loads and influent concentrations. Raman spectroscopy analysis revealed that polyvinyl alcohol (PVA) was the predominant polymer type. Rural WWTPs were more effective at removing large-sized particles (> 0.1 mm) and films, resulting in higher removal effectiveness by weight (49.1 %) compared to urban WWTPs (30.8 %). Based on the abundance of microplastics in WWTPs within the study area and China's annual sewage discharge, this study estimated the microplastic emissions released through sewage in China in 2022. The annual microplastic emissions through sewage in China were estimated to be 2995.7 tons, with rural and urban areas contributing 25.1 % and 74.9 %, respectively. Approximately 724.8 tons and 1001.6 tons of microplastics were removed from rural and urban WWTPs, respectively. This work indicates the unignorable emissions of microplastics from rural sewage and highlights the crucial role of rural WWTPs in reducing microplastic pollution.

Oxygen Reduction Reaction Coupled Electro‐Oxidation for Highly‐Efficient and Sustainable Water Treatment

AbstractElectro‐oxidation (EO) technology demonstrates significant potential in wastewater treatment. However, the high energy consumption has become a pivotal constraint hindering its large‐scale implementation. Herein, we design an EO and 4‐electron oxygen reduction reaction coupled system (EO‐4eORR) to replace the traditional EO and hydrogen evolution reaction (HER) coupled system (EO‐HER). The theoretical cathodic potential of the electrolytic reactor is tuned from 0 V (vs. RHE) in HER to 1.23 V (vs. RHE) in 4eORR, which greatly decreases the required operation voltage of the reactor. Moreover, we demonstrate that convection can improve the mass transfer of oxygen and organic pollutants in the reaction system, leading to low cathodic polarization and high pollutant removal rate. Compared with traditional EO‐HER system, the energy consumption of the EO‐4eORR system under air aeration for 95 % total organic carbon (TOC) removal is greatly decreased to 2.61 kWh/kgTOC (only consider the electrolyzer energy consumption), which is superior to previously reported EO‐based water treatment systems. The reported results in this study offer a new technical mode for development of highly efficient and sustainable EO‐based treatment systems to remove organic pollutants in waste water.

Oxygen Reduction Reaction Coupled Electro-Oxidation for Highly-Efficient and Sustainable Water Treatment.

Electro-oxidation (EO) technology demonstrates significant potential in wastewater treatment. However, the high energy consumption has become a pivotal constraint hindering its large-scale implementation. Herein, we design an EO and 4-electron oxygen reduction reaction coupled system (EO-4eORR) to replace the traditional EO and hydrogen evolution reaction (HER) coupled system (EO-HER). The theoretical cathodic potential of the electrolytic reactor is tuned from 0 V (vs. RHE) in HER to 1.23 V (vs. RHE) in 4eORR, which greatly decreases the required operation voltage of the reactor. Moreover, we demonstrate that convection can improve the mass transfer of oxygen and organic pollutants in the reaction system, leading to low cathodic polarization and high pollutant removal rate. Compared with traditional EO-HER system, the energy consumption of the EO-4eORR system under air aeration for 95 % total organic carbon (TOC) removal is greatly decreased to 2.61 kWh/kgTOC (only consider the electrolyzer energy consumption), which is superior to previously reported EO-based water treatment systems. The reported results in this study offer a new technical mode for development of highly efficient and sustainable EO-based treatment systems to remove organic pollutants in waste water.

Enhanced desalination performance of flow capacitive deionization with the addition of conductive polymer in redox couples and activated carbon

Freshwater scarcity is a critical global issue and desalination of brackish water and seawater technologies are regarded as effective solution to mitigate the increasing severity of water shortage. Flow-electrode capacitive deionization (FCDI) is an emerging electrochemical desalination technology capable of continuous deionization behavior. However, reducing energy consumption and enhancing desalination rate are now markedly needed for its advancement. Herein, we propose a FCDI system with energy consumption as low as 88.08 kJ mol−1 and a desalting rate of 1.75 μg cm−2 s−1. This is achieved by using flow electrodes containing 0.03125 wt% conductive polymer, 5 wt% activated carbon/carbon black and 80 mM/80 mM ferricyanide/ferrocyanide at a current density 3 mA cm−2 (3.36 mA current for a 1.12 cm2 active area). We further investigate the effects of polymer content, redox pair content, salt content and current densities on desalination performance. Seawater with a conductivity of 52.78 mS cm−1 was successfully desalinated to 0.50 mS cm−1 in continuous process. This research provides a promising approach to enhance FCDI system by achieving a low energy consumption and high salt removal rate, representing a significant advancement in continuous electrochemical desalination technology.

Effect of manufacturing new U-shaped electrode on die sinking EDM process performance

Traditional electrical discharge machining (EDM) electrodes have several limitations such as long machining time, low material removal rate MRR, hazard emissions and high energy consumption. To overcome these limitations, new electrodes (plane and frame U-shaped) were manufactured considering the electrode manufacturing classifications, such as electrode flushing mechanism, electrode cross-sectional area and electrode bottom machining area. Experiments were performed on a die-sinking EDM machine using copper electrodes and aluminum alloy workpieces. The results were compared with those obtained using the conventional electrode. The newly manufactured electrodes significantly improved the EDM process performance, reducing the machining time by more than 50%, which implies a higher MRR. The reduced machining time also led to lower costs, emissions and energy consumption for efficient EDM processes. Additionally, surface roughness measurements were performed to compare the surface quality of the machined areas using different pulse-code generator systems and electrodes. The results showed an improvement in the machined surface quality when using the new electrodes in comparison with the conventional electrode when using a roughing pulse code generator system.

Enhanced removal of nanoplastics from freshwater using in-situ synthesized and anchored nano-Fe3O4 via two-step ferrous oxidation

Magnetic separation is a promising strategy for removing nanoplastics (NPs) from water; however, it often requires complex processeses, such as synthesizing nano-Fe3O4 magnets and attaching them to specific carriers. This study presents an innovative and efficient strategy to in-situ synthesize and anchor nano-Fe3O4 onto polystyrene (PS) NPs through a two-step oxidation of ferrous ions, which significantly enhances NPs removal via magnetic separation. The two-step process involves initial alkalization of a ferrous aqueous solution under anoxic conditions, followed by oxidation in air. In the presence of PS spheres, nano-Fe3O4 forms in-situ on the PS surfaces, promoting sedimentation under a magnetic field. Results demonstrate that two-step ferrous oxidation achieves superior removal rates, with 99.32 % for 500 nm PS spheres (PS-500) and 93.16 % for 100 nm PS spheres (PS-100) using a low Fe2+ dosage of 0.1 mM. In contrast, the conventional one-step method, which simultaneously alkalizes and oxidizes ferrous sulfate in aerobic conditions, fails to form nano-Fe3O4 and results in low removal rates of only 56.49 % for PS-500 and 8.89 % for PS-100, respectively. Furthermore, the turbidity and residual Fe can be reduced to below 1 NTU and 0.1 mg/L by using two-step process, respectively, meeting drinking water safety and hygiene standards. This approach not only simplifies the magnetic nanomaterial preparation process but also substantially improves the NP removal efficiency, offering a promising solution for enhanced water treatment technologies and safer drinking water.

Occurrence and Ecological Risk Assessment of Highly Toxic Halogenated Byproducts during Chlorination Decolorization of Textile Printing and Dyeing Wastewater.

Textile printing and dyeing wastewater is a substantial source of highly toxic halogenated pollutants because of the chlorination decolorization. However, information on the occurrence and fate of the highly toxic halogenated byproducts, which are produced by chlorination decolorization of the textile printing and dyeing wastewater, is very limited. In this study, the occurrence of six categories of halogenated byproducts (haloacetic acids (HAAs), haloacetonitriles (HANs), N-nitrosamines (NAs), trihalomethanes, halogenated ketones, and halonitromethanes) was investigated along the full-scale treatment processes of textile printing and dyeing wastewater treatment plants. Furthermore, the ecological risk of the halogenated byproducts was evaluated. The results showed that the total concentration of halogenated byproducts increased significantly after chlorination. Large amounts of HAAs (average 122.1 μg/L), HANs (average 80.9 μg/L), THMs (average 48.3 μg/L), and NAs (average 2314.3 ng/L) were found in the chlorinated textile wastewater, and the results showed that the generations of HANs and NAs were positively correlated with the BIX and β/α index, indicating that the HANs and NAs might form from the microbial metabolites. In addition, HAAs and HANs exhibited high ecological risk quotients (>1), suggesting their high potential ecological risk. The results also demonstrated that most halogenated byproducts could be effectively removed by reverse osmosis treatment processes except NAs, with a lower removal rate of 18%. This study is believed to provide an important theoretical basis for controlling and reducing the ecological risks of halogenated byproducts in textile printing and dyeing wastewater effluents.

Nitrogen reducing mechanism by microporous aeration based on microbial population characteristics: water temperature factor

ABSTRACT The formation of black odour water is primarily attributed to the elevated concentration of organic pollutants, along with an excessive amount of nitrogen and phosphorus, ultimately leading to an anoxic aquatic environment. The water temperature influence mechanism on black-odorous water restoration by microporous aeration is still lacking depth study. This paper selected (15–18) ℃ (spring and autumn), (22–25) ℃ (summer), (8–11) ℃ (winter) as temperature conditions, and investigated temperature influence on nitrogen reduction. Researches showed that: (1) The removal rates of COD, NH4 +-N and TN were significantly positively correlated with temperature (r = 0.99, 0.96, 0.97), the lowest removal rates were 83.16%, 95.68%, 58.7% ((8–11) ℃), the highest values were 92.67%, 98.27%, 70.96% ((22–25) ℃), respectively. (2) At a temperature range of 22–25°C, the microbial community exhibited the highest levels of abundance, diversity, and uniformity. Notably, Proteobacteria dominated this temperature range with a relative abundance of 79.72%. Furthermore, temperature positively correlated with the majority of dominant bacterial species, suggesting that conditions at 22–25°C are highly conducive to the growth of most bacterial communities. Among these, Limnohabitans, Alsobacter, and Candidatus_Aquirestis, which possess key functions in denitrification and nitrogen removal, displayed significantly higher abundances. It explains the positive correlation between temperature and removal rates of COD, TN and NH4 +-N from microbial population’s perspective. Thus, the best temperature for repairing black-smelly water is (22–25) ℃. This study provides technical reference for mechanism research and practical application of microporous aeration.

A simple modified technique for screw fixation of displaced intra-articular calcaneus fracture through a sinus tarsi approach: a comparison with plate fixation

BackgroundPlates and screws are frequently used for the fixation of displaced intra-articular calcaneus fracture (DIACF). In this study, we compared the outcomes of a modified screw fixation technique with plate fixation via a sinus tarsi approach (STA).MethodsA series of 187 DIACF patients who were treated via an STA using a plate fixation (n = 81) or a screw fixation (n = 106) were included. Screw fixation was done with two 2.7 mm screws and two 6.5 mm cannulated screws. Outcomes were evaluated radiographically and clinically. Clinical evaluations included pain assessment by Visual Analogue Scale (VAS) and functional assessment by the American Orthopaedic Foot and Ankle Society (AOFAS) questionnaire and Foot Function Index (FFI).ResultsThe mean final VAS was smaller in the screw group (P = 0.01). The mean AOFAS and FFI scores were not significantly different between the two groups (P = 0.17 and P = 0. 19, respectively). The mean improvement of Bohler’s angle, but not the Gissane’s angle, was significantly greater in the screw group (P = 0.014 and P = 0.09, respectively). The mean improvement of calcaneal length and height were not significantly different between the two groups (P = 0.78 and P = 0.22, respectively). The hardware removal rate was 14.8% in the plate group and 3.8% in the screw group (P = 0.007).ConclusionThe modified screw fixation method provides lower pain, better radiographic outcome, and lower rate of hardware removal compared to plate fixation in the treatment of DIACF.

Reuse and Recovery of Water from Industrial Textile Dyeing Effluent Using High-Performance Electrodes Continuous Flow Electrocoagulation Reactor

The dye effluents released from the textile and printing industries contain strong colorants, inorganic salts, and other toxic compounds. The conventional coagulation technique of dye effluent treatment is plagued with issues of low removal rate of color, generation of large quantities of sludge, and toxic end-products. Recently electrocoagulation technique gained immense attention due to its high efficiency. This technique involves the dissolution of the sacrificial anodes to provide an active metal hydroxide as a strong coagulant that destabilizes the pollutants and removes them by precipitation or flocculation. This study is about the efficiency of the electrocoagulation process using titanium coated - aluminum and mild steel electrodes to treat industrial dye wastewater. Effects of parameters such as current density &amp; initial dye concentration were investigated. It was observed that, for the same current density, electrode consumption was higher with TiO2/Al electrode than with mild steel electrode, resulting in more color removal efficiency (CRE) using TiO2/Al electrode. The settling rate of the flocs was higher in the rector having TiO2/Al electrode at the 100 mL with current density (2.5 mL.min-1 to 5.3 mL.min-1), while in the reactor with mild steel electrode, the settling rate was very less. The results showed that dye removal was 95.11% and 92.1% for mild steel and titanium-coated electrodes, respectively. It was observed that 50 % of Aluminum was removed from the treated effluent after the final stage of filtration. Based on the multicriteria analysis to identify the optimum operational parameters to be applied at the field level, it was observed that maximum CRE may be obtained with TiO2/Al electrode and the applied current of 1 Amps with a flow rate of 100 mL.min-1. It can be concluded that electrocoagulation is a highly efficient and the fastest method to treat dye effluents from industries.

Enhancing microplastic removal from natural water using coagulant aids

Microplastic (MP) pollution poses a significant environmental challenge, underscoring the need for improved water treatment methods. This study investigates the effectiveness of coagulation, flocculation, and sedimentation processes for removing microbeads, focusing on key factors that influence removal efficiency. Among the coagulants tested, polyaluminium chloride (PAC) demonstrated superior performance by enhancing the aggregation of microplastics with flocs. Optimal treatment conditions were determined to be 0.4 mmol/L PAC and 3 mg/L polyacrylamide (PAM) at pH 8 (before adding PAC), with rapid stirring at 240 rpm for 1 min, followed by slow stirring at 35 rpm for 13 min, and a sedimentation period of 25 min. Under these conditions, removal efficiencies exceeded 95 % for a range of microbeads (10–1000 μm: Polystyrene (PS), Polypropylene (PP), Polyvinyl chloride (PVC), Polyamide (PA), Polyethylene (PE), and Polyurethane (PU)) from natural water samples. Without PAM, PAC alone achieved a 97 % removal rate for PS microbeads. The addition of PAM maintained high removal efficiency, while aluminium sulphate and ferric chloride were less effective, with removal rates of 67 % and 48 % for PS microbeads, respectively. PAM enhanced MP removal across various coagulants and microbead types, with maximum efficiency observed at PAM concentrations of ≥3 mg/L. The treatment also demonstrated that organic matter in Regent's Park pond water could further improve MP removal. Size significantly impacts removal efficiency: larger microbeads (1 mm to >250 μm) were removed more effectively (95 %) compared to smaller ones (10 to <250 μm), which had a lower removal rate of 49 %. Denser microbeads like PVC (density 1.38 g/cm³) settled more efficiently than lighter microbeads such as PE (density 0.97 g/cm³). These findings suggest a need for advanced technologies to better remove lighter, smaller MPs from water.

Thermophilic bacterial agent inoculation enhances biodrying of kitchen waste: Insights into process properties, organic degradation, bacterial communities and metabolic pathways

The high moisture content of kitchen waste (KW) restricts the future treatment and resource utilization. Biodrying is an effective approach to remove the water of KW. However, conventional biodrying only uses the heat generated by the indigenous microorganisms to remove water, which has long treatment cycle and low moisture removal rate. Microbial bioaugmentation is an emerging approach to improve the biodrying efficiency of KW. In this study, a thermophilic bacterial agent (TBA) composed of Bacillus, Geobacillus and Acinetobacter was used to promote water evaporation during the biodrying process. Based on the results, the moisture removal rate of experimental group inoculated with TBA was 82.20 %, which was notably higher than CK group without inoculation. Moreover, TBA significantly increased the amount of organic matter degradation. Microbial community analysis revealed that TBA could promote the proliferation of thermophilic bacteria and make bacterial community more tolerant to high temperature environment. Further analysis of metabolic pathways showed that quorum sensing and glyoxylate and dicarboxylate metabolism were enhanced by TBA inoculation, which can help microorganisms to better adapt to high temperature environment and release more energy to facilitate the water evaporation. This study offers a fresh approach to improve the water removal efficiency in biodrying process.

Exploring fecal sludge treatment technologies in humanitarian settings at Cox’s Bazar, Bangladesh: a comprehensive assessment of treatment efficiency through characterization of fecal sludge

IntroductionEfficient treatment of fecal sludge in densely populated settings is essential as it has a direct impact on public health and the environment. This study presents a comprehensive assessment of fecal sludge treatment technologies in Rohingya camps at Cox’s Bazar, Bangladesh, focusing on removal efficiencies and compliance with regulatory standards.MethodsSeventeen treatment plants of five different technologies were evaluated based on removal efficiency and standard discharge guidelines for various physicochemical and microbiological parameters.ResultsWaste Stabilization Pond (WSP) was the top performer compared to four other different treatment technologies evaluated, achieving notable removal rates: 97.3% reduction in E. coli, 100% in helminth eggs, 98.3% for COD, 97.8% for BOD, 98.7% for TSS, 92.1% for TS, 82.8% for phosphate, and 93.3% for total nitrogen. Lime Stabilization Ponds showed lower removal rates, except for E. coli (98.9%), with reductions of 99.7% for helminth eggs, 81.6% for COD, 80.9% for BOD, 86.3% for TSS, 68.6% for TS, and 49.2% for phosphate. Upflow Filters demonstrated good removal efficiencies for E. coli (99.7%), TSS (95.9%), COD (91.7%), BOD (93.5%), and helminth eggs (93.7%). WSP consistently outperformed other technologies across all seasons. Despite these, none of the technologies fully met discharge standards.DiscussionThese findings highlight the need for a comprehensive approach, the combination of physicochemical and biological processes, to enhance efficacy. Promoting improved fecal sludge management technologies through awareness campaigns and technical support can mitigate environmental health risks in densely populated humanitarian settings.