Biofilm growth characteristic and footprint identification in gravity-driven ceramic membrane bioreactor with electro-coagulation under extreme conditions for roofing rainwater purification.

The identification of biofilm growth footprints influencing on the biofilm detachment and breakup can advance research into how biofilms form. Thus, a gravity-driven ceramic membrane bioreactor (GDCMBR) was used to investigate the growth, detachment and breakup of biofilm using rainwater pretreated by electrocoagulation under 70-days continuous operation. The in-situ ultrasonic time-domain reflectometry (UTDR) technique was applied to non-invasively determine the biofilm thickness. Initially, the biofilm was slowly thickening, but it would collapse and became thinner after accumulating to a certain level, and then it thickened again in a later period, following a cyclic pattern of 'thickening - collapsing - thickening'. This is because the biofilm growth is related with the accumulation of flocs, however, excessive floc formation results in the biofilm being overweight till reaching the thickness limit and thus collapsing. Subsequently, the biofilm gradually thickens again due to the floc production and continuous deposition. Although the biofilm was dynamically changing, the water quality of treatment of the biofilm always remained stable. Ammonia nitrogen and total phosphorus have been almost completely removed, while CODMn removal efficiency was around 25%. And total bacteria amount in the membrane concentrate was obviously higher than that in the influent with the greater microbial activity, demonstrating the remarkable enrichment effect on bacteria. The understanding of biofilm growth characteristic and footprint identification enables us to develop rational approaches to control biofilm structure for efficient GDCMBR performance and operation lifespan.

Non-thermal technologies for broiler litter processing: Microbial safety, chemical composition, nutritional value, and fermentation parameters in vitro.

BACKGROUND: Annually, a massive amount of broiler litter (BL) is produced in the world, which causes soil and surface water pollution due to its high nitrogen content and microbial count. While ruminants can use this non-protein nitrogen (NPN) source for microbial protein synthesis. This issue becomes more critical when protein sources are unavailable or very expensive. One of the sources of NPN is BL which is produced at a considerable amount in the world yearly. OBJECTIVES: This aim of this research was to conduct a survey of non-thermal technologies such as electrocoagulation (EC), ultraviolet (UV) radiation, and ultrasound (US) waves on the microbial safety and nutritional value of BL samples as a protein source in ruminant diets. MATERIALS AND METHODS: The methodology of this study was based on the use of an EC device with 24 V for 60 min, UV-C light radiation (249 nm) for 1 and 10 min, and US waves with a frequency of 28 kHz for 5, 10 and 15 min to process BL samples compared with shade-dried samples. Chemical composition and nutritional values of processed samples were determined by gas production technique and measurement of fermentation parameters in vitro. RESULTS: Based on the results, microbial safety increased in the samples processed with the US (15 min). The EC method had the best performance in reducing the number of fungi and mould. However, none of the methods could remove total bacteria and fungi. Digestibility of BL was similar in shade-dried, EC, and US (10 min) treatments. In general, the use of EC and US15 without having adverse effects on gas production caused a decrease in the concentration of ammonia nitrogen. In contrast, it caused a decrease in neutral detergent fibre (NDF) in the investigated substrate. CONCLUSIONS: In general, it can be concluded that the use of US5 and EC methods without having a negative effect on the parameters of gas production and fermentation in vitro, while reducing NDF, causes a significant reduction in the microbial load, pathogens, yeast, and mould. Therefore, it is suggested to use these two methods to improve feed digestibility for other protein and feed sources.

Investigating the efficiency of electrocoagulation using similar/dissimilar electrodes for the detoxification of Coralene Rubine dye: a cost effective approach.

Efficient treatment of textile dyeing wastewater can be achieved through electrocoagulation (EC) with minimal sludge production; however, the selection of the appropriate electrode is essential in lowering overall costs. Also, the reuse of the treated aqueous azo dye solution from this process has not been explored in detail. With these objectives, this study aims to treat synthetic azo dye solutions and achieve high colour removal efficiency (CRE%) using similar (Ti-Ti) and dissimilar (Ti-Cu) metal electrodes through EC with an attempt to reduce the cost. The aqueous Coralene Rubine GFL azo dye was used to examine the efficiency and cost of the EC process. X-Ray Photoelectron Spectroscopy was used to study the EC mechanism, while High Performance Liquid Chromatography was used to analyse the degradation of the dye and the formation of intermediate compounds. The concentration of metal ions in the treated dye solution was quantified using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), with Ti-Ti treated solution having 14.20 mg/L concentration of Ti and Ti-Cu treated solution having 0.078 mg/L of Ti and 0.001 mg/L of Cu, respectively. Colour removal efficiency of 99.49% was obtained for both electrode sets, with a lower operating time and voltage for dissimilar metal combination. Ecotoxicity studies showed negligible toxicity of Ti-Cu treated dye samples compared to untreated solutions. Survival rate, protein estimation, and catalase activity was used to validate the treatment method's efficacy. The study found that the dissimilar electrode material exhibited reduced toxicity due to the presence of heavy metals below the permissible limit.

Importance of iron complexation and floc formation towards phosphonate removal with Fe-electrocoagulation.

Phosphonates are widely used scale inhibitors, but the residual phosphonates in drainage are challenging to remove because of their chelating capacity and resistance to biodegradation. Here, we reported a highly efficient and robust Fe-electrocoagulation (Fe-EC) system for phosphonate removal. Surprisingly, we found for the first time that phosphonates like NTMP were more efficiently removed under anoxic conditions (80% of total soluble phosphorus (TSP) in 4 min) than oxic conditions (0% of TSP within 6 min) in NaCl solution. A similar phenomenon was observed when other phosphonates, such as EDTMP and DTPMP, were removed, highlighting the importance of iron complexation and floc formation toward phosphonate removal with Fe-EC. We also showed that the removal efficiency of NTMP by electrochemically in-situ formed flocs (97%) was much higher than post-adsorption systems (ex-situ, 40%), revealing that the growth of flocs consumed the active site for NTMP adsorption. Beyond the removal of TSP, 10 % of NTMP-P was also degraded after the electrolysis phase, evidenced by the evolution of phosphate-P. However, this did not happen in anoxic or chemical coagulation processes, which confirms the formation of reactive oxygen species via Fe(II) oxidation in the oxic Fe-EC system. The primary removal mechanism of phosphonates is due to their complexation with iron (hydr)oxide generated in the Fe-EC system by forming a Fe-O-P bond. Encouragingly, the Fe-EC system exhibits comparable or even better performance in treating phosphonate-laden wastewater (i.e., cooling water). Our preliminary cost calculation suggests the proposed system (€ 0.009/m3) has a much lower OPEX under oxic conditions than existing approaches. This study sheds light on the removal mechanism of phosphonate and the treatment of phosphonate-laden wastewater by playing with the iron complexion and flocs formation in classical Fe-EC systems.

Efficiency enhancement of electrocoagulation, ion-exchange resin and reverse osmosis (RO) membrane filtration by prior organic precipitation for treatment of anaerobically-treated palm oil mill effluent.

Anaerobically-treated palm oil mill effluent (POME) still has unacceptable properties for water recycling and reuse, with an unpleasant appearance due to the brownish color caused by tannins and phenolic compounds. This study proposes an approach for treating anaerobically-treated POME for water recycling by combining organic precipitation, electrocoagulation (EC), and ion-exchange resin, followed by reverse osmosis (RO) membrane filtration in series. The results indicated that the organic precipitation enhanced the efficiency of EC treatment in reducing the concentrations of tannins, color, and chemical oxygen demand (COD) of the anaerobically-treated POME effluent, with reductions of 95.73%, 96.31%, and 93.96% for tannin, color, and COD, respectively. Moreover, organic precipitation affected the effectiveness of Ca2+ and Mg2+ ion removal using ion exchange resin and RO membrane filtration. Without prior organic precipitation, the ion-exchange resin process required a longer contact time, and the RO membrane filtration treatment was hardly effective in removing total dissolved solids (TDS). The combined process gave a water quality that meets the criteria set by the Thailand Ministry of Industry for industrial boiler use (COD 88 mg/L, TDS <0.001 mg/L, water hardness <5 mg-CaCO3/L, and pH 6.9).

Application of prostate resectoscope in the treatment of massive rectal bleeding after transrectal prostate puncture.

BACKGROUND: Ultrasound-guided prostate biopsy is a reliable diagnostic procedure for prostate cancer diagnosis with minimal procedure-related trauma. However, complications, such as massive rectal bleeding may occur after the puncture. We hypothesized that using a transrectal resectoscope could help treat massive rectal bleeding after transrectal prostate punctures. AIM: To identify a simple and effective treatment for massive rectal bleeding after transrectal prostate punctures. METHODS: Patients requiring treatment for massive rectal bleeding after transrectal prostate punctures were included. A SIMAI resectoscope was inserted through the anus. Direct electrocoagulation was performed for superficial bleeding points. Part of the rectal mucosa or surface muscle layer was removed to expose deep bleeding points, followed by electrocoagulation. An electric cutting ring was used to compress and stop the bleeding for jet-like points before electrocoagulation. The fluid color in the drainage tube was monitored postoperatively for continuous bleeding. RESULTS: Eight patients were included from 2012 to 2022. None of the patients with massive rectal bleeding after the transrectal prostate punctures improved with conventional conservative and blood transfusion treatments. Two patients had an inferior artery embolism, and digital subtraction angiography was ineffective. All patients received emergency transanal prostate resection, which immediately stopped the bleeding. Four days after the procedure, the patients had recovered and were discharged. CONCLUSION: Using a transanal prostate resection instrument is a simple, safe, and effective method for treating massive rectal bleeding after transrectal prostate punctures.

Optimization and kinetic analysis of electrocoagulation-assisted adsorption for treatment of young landfill leachate.

An investigation was conducted on the electrocoagulation treatment of high-strength young landfill leachate using an electrode made of aluminium in a batch electrochemical cell reactor. An iron sheet of 1 m⨯1 m⨯1.1 m (L: B: H) was used to construct the two landfill simulating reactors, both the reactors were operated at different conditions, i.e., one without rainfall (S1) and the other with rainfall (S2). Both reactors have 51% wet and 49% dry waste, which is the typical waste composition of India, and the quantity of waste taken was 450 kg; hence, the generated leachate was treated. This work focuses on the utilization of electrocoagulation as the sole treatment method where coagulation and adsorption occur simultaneously for young landfill leachate. The study employed a central composite design (CCD) to systematically vary the initial pH, current density (CD), and reaction time to examine their impact on the removal efficiency of COD (Chemical oxygen demand), TOC (Total organic carbon), and TSS (Total Suspended Solids). The optimum conditions obtained were a pH of 7.35, a CD of 15.29 mA/cm2, and a reaction duration of 57 min. When the conditions were optimized, the COD, TSS, and TOC removal efficiencies were 83.56%, 73.12%, and 85.58%, respectively. Also, the electrodes depleted 2.78 g of Al/L. In addition, pseudo-first-order and pseudo-second-order kinetics were employed to examine the elimination of contaminants by adsorption on aluminium hydroxide, thereby confirming the adsorption process. After investigation through energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD), with the produced sludge confirmed that electrocoagulation removed a significant amount of metals from landfill leachate.

Optimization of electrocoagulation process parameters for the treatment of oil industry drill site wastewater.

The effluent from the oil drilling site is a complex mixture of hazardous chemicals that causes environmental impacts on its disposal. The treatment of oil drill-site wastewater has not been explored much, and understanding its characteristics and optimizing the treatment process are required. In the present study, we have optimized the electrocoagulation process with aluminum electrodes for drill-site wastewater treatment. A multi-level factorial center composite design using response surface methodology is applied to optimize the effect of current density (CD), pH, and inter-electrode distance (IED) on chemical oxygen demand (COD) removal. The increasing current density shows a significant increase in COD removal, and a similar trend was observed with a decreased pH. It was found that with current density and inter-electrode distance, the maximum COD removal achieved was 70% at the CD of 19.04 mA cm-2 and IED 2.6 cm. By varying pH and current density, the COD removal reached up to 90% at pH 6 and CD 19.04 mA cm-2. The study shows that the current density is the dominant factor for the process's energy consumption and operating cost, followed by pH. This study's findings could be effectively used to develop large-scale treatment processes through electrocoagulation.

Analysis of factors influencing on Electro-Fenton and research on combination technology (II): a review.

The principle of Fenton reagent is to produce ·OH by mixing H2O2 and Fe2+ to realize the oxidation of organic pollutants, although Fenton reagent has the advantages of non-toxicity and short reaction time, but there are its related defects. The Fenton-like technology has been widely studied because of its various forms and better results than the traditional Fenton technology in terms of pollutant degradation efficiency. This paper reviews the electro-Fenton technology among the Fenton-like technologies and provides an overview of the homogeneous electro-Fenton. It also focuses on summarizing the effects of factors such as H2O2, reactant concentration, reactor volume and electrode quality, reaction time and voltage (potential) on the efficiency of electro-Fenton process. It is shown that appropriate enhancement of H2O2 concentration, voltage (potential) and reaction volume can help to improve the process efficiency; the process efficiency also can be improved by increasing the reaction time and electrode quality. Feeding modes of H2O2 have different effects on process efficiency. Finally, a considerable number of experimental studies have shown that the combination of electro-Fenton with ultrasound, anodic oxidation and electrocoagulation technologies is superior to the single electro-Fenton process in terms of pollutant degradation.

Risk Factors for Post-Endoscopic Submucosal Dissection Electrocoagulation Syndrome in Patients with Colorectal Neoplasms: A Multicenter, Large-Scale, Retrospective Cohort Study by the Honam Association for the Study of Intestinal Disease (HASID).

Background and Objectives: Colorectal endoscopic submucosal dissection (ESD) is an effective technique for removing colorectal neoplasms with large or cancerous lesions. However, there are few studies on post-ESD electrocoagulation syndrome (PECS), a complication of colorectal ESD. Therefore, this study aimed to investigate the various risk factors for PECS after colorectal ESD. Materials and Methods: We retrospectively analyzed the medical records of 1413 lesions from 1408 patients who underwent colorectal ESD at five tertiary hospitals between January 2015 and December 2020. We investigated the incidence and risk factors associated with PECS. Based on the data, we developed a risk-scoring model to predict the risk of PECS after colorectal ESD. Results: The incidence rate of PECS was 2.6% (37 patients). In multivariate analysis, the use of anti-platelet agents (odds ratio (OR), 2.474; 95% confidence interval (CI), 1.088-5.626; p < 0.031), a lesion larger than 6 cm (OR 3.755; 95% CI, 1.237-11.395; p = 0.028), a deep submucosal invasion (OR 2.579; 95% CI, 1.022-6.507; p = 0.045), and an ESD procedure time ≥ 60 min (OR 2.691; 95% CI, 1.302-5.560; p = 0.008) were independent risk factors of PECS after colorectal ESD. We developed a scoring model for predicting PECS using these four factors. As the score increased, the incidence of PECS also increased, from 1.3% to 16.6%. PECS occurred more frequently in the high-risk group (≥2) (1.8% vs. 12.4%, p < 0.001). Conclusions: In this study, the risk factors for PECS after colorectal ESD were the use of anti-platelet agents, a lesion larger than 6 cm, a deep submucosal invasion, and an ESD procedure time ≥ 60 min. The risk-scoring model developed in this study using these factors could be effective in predicting and preventing PECS.

Treatment of azo dye-containing wastewater in a combined UASB-EMBR system: Performance evaluation and membrane fouling study.

This work investigated the treatment of azo dye-containing wastewater in an upflow anaerobic sludge blanket (UASB) reactor combined with an electro-membrane bioreactor (EMBR). Current densities of 20 A m-2 and electric current exposure mode of 6'ON/30'OFF were applied to compare the performance of the EMBR to a conventional membrane bioreactor (MBR). The results showed that dye (Drimaren Red CL-7B) removal occurred predominantly in the UASB reactor, which accounted for 57% of the total dye removal achieved by the combined system. When the MBR was assisted by electrocoagulation, the overall azo dye removal efficiency increased from 60.5 to 67.1%. Electrocoagulation batch tests revealed that higher decolorization rates could be obtained with a current density of 50 A m-2. Over the entire experimental period, the combined UASB-EMBR system exhibited excellent performance in terms of chemical oxygen demand (COD) and NH4+-N removal, with average efficiencies above 97%, while PO43--P was only consistently removed when the electrocoagulation was used. Likewise, a consistent reduction in the absorption spectrum of aromatic amines was observed when the MBR was electrochemically assisted. In addition to improving the pollutants removal, the use of electrocoagulation reduced the membrane fouling rate by 68% (0.25-0.08 kPa d-1), while requiring additional energy consumption and operational costs of 1.12 kWh m-3 and 0.32 USD m-3, respectively. Based on the results, it can be concluded that the combined UASB-EMBR system emerges as a promising technological approach for textile wastewater treatment.

Defluoridation by positive single-pulse current electrocoagulation from photovoltaic wastewater: Energy consumption assessment and mechanism analysis.

The presence of fluoride ions (F-) in photovoltaic (PV) wastewater significantly affects the integrity of the ecological environment. In contrast to direct current electrocoagulation (DC-EC), positive single-pulse electrocoagulation (PSPC-EC) shows a significant reduction in both the formation of passivation films on electrodes and the consumption of electrical energy. Under the experimental conditions of an Al-Al-Al-Al electrode combination, an electrode spacing of 1.0 cm, a NaCl concentration of 0.05 mol L-1, an initial pH of 5.6, an initial F- concentration of 5 mg L-1, a current density of 5 A m-2, a pulse frequency of 500 Hz, and a 40 % duty cycle, the achieved equilibrium F- removal efficiencies were 84.0 % for DC-EC and 88.0 % for PSPC-EC, respectively, accompanied by power consumption of 0.0198 kWh·mg-1 and 0.0073 kWh·mg-1. The flocs produced in the PSPC-EC process were characterized using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy and it is revealed that the F- removal mechanisms in the PSPC-EC process include co-precipitation, hydrogen bond complexation, and ion exchange. When the actual PV wastewater was finally subjected to treatment under the optimal PSPC-EC conditions, the F- concentration in the wastewater was reduced from 4.6 mg L-1 to 1.4 mg L-1. This paper provides both a theoretical framework and a technological basis for the application of PSPC-EC in the advanced treatment of PV wastewater.

Optimization of iron electrocoagulation parameters for enhanced turbidity and chemical oxygen demand removal from laundry greywater.

This study explores the optimization of iron electrocoagulation for treating laundry greywater, which accounts for up to 38% of domestic greywater. Characterized by high concentrations of surfactants, detergents, and suspended solids, laundry greywater presents complex challenges for treatment processes, posing significant environmental and health risks. Utilizing response surface methodology (RSM), this research developed a second-order polynomial regression model focused on key operational parameters such as the area-to-volume ratio (A/V), current density, electrolysis time, and settling time. Optimal treatment conditions were identified: an A/V ratio of 30 m2/m3, a current density of 10 mA/cm2, an electrolysis duration of 50 min, and a settlement period of 12 h. Under these conditions, exceptional treatment outcomes were achieved, with turbidity removal reaching 94.26% and COD removal at 99.64%. The model exhibited high effectiveness for turbidity removal, with an R2 value of 94.16%, and moderate effectiveness for COD removal, with an R2 value of 75.90%. The interaction between the A/V ratio and electrolysis time particularly underscored their critical role in electrocoagulation system design. Moreover, these results highlight the potential for optimizing electrocoagulation parameters to adapt to daily fluctuations in greywater production and meet specific household reuse needs, such as toilet flushing. This tailored approach aims to maximize contaminant separation and coagulant efficiency, balance energy use and operational costs, and contribute to sustainable water management.

A new model of electrosurgical tissue damage for neurosurgery simulation.

BACKGROUND: Bipolar hemostasis electrocoagulation is a fundamental procedure in neurosurgery. A precise electrocoagulation model is essential to enable realistic visual feedback in virtual neurosurgical simulation. However, existing models lack an accurate description of the heat damage and irreversible tissue deformation caused by electrocoagulation, thus diminishing the visual realism. This work focuses on the electrocoagulation model for neurosurgery simulation. METHOD: In this paper, a position-based dynamics (PBD) model with a bioheat transfer and damage prediction (BHTDP) method is developed for simulating the deformation of brain tissue caused by electrocoagulation. The presented BTHDP method uses the Arrhenius equation to predict thermal damage of brain tissue. A deformation model with energy and thermal damage constraints is developed to characterize soft tissue deformation during heat absorption before and after thermal injury. Visual effect of damaged brain tissue is re-rendered. RESULT: To evaluate the accuracy of the proposed method, numerical simulations were conducted and compared with commercial finite element software. The maximum normalized error of the proposed model for predicting midpoint temperature is 10.3 % and the maximum error for predicting the thermal damage is 5.4 %. The contraction effects of heat-exposed anisotropic tissues are also simulated. The results indicate that the presented electrocoagulation model provides stable and realistic visual effects, making it applicable for simulating the electrocoagulation process in virtual neurosurgery.

Association of local steroid injection as a risk factor for electrocoagulation syndrome after esophageal endoscopic submucosal dissection.

BACKGROUND: Postendoscopic submucosal dissection electrocoagulation syndrome (PEECS) is commonly observed after performing endoscopic submucosal dissection (ESD) for esophageal neoplasia. However, data on the incidence and risk factors for PEECS in the esophagus are lacking due to an unclear definition of PEECS and varied clinical settings. Therefore, we aimed to determine the risk factors for PEECS in patients undergoing ESD for esophageal neoplasia. METHODS: We retrospectively reviewed data of relevant clinical and endoscopy-specific parameters from 202 consecutive patients with esophageal neoplasias (139 carcinomas and 63 dysplasias) who underwent ESD under general anesthesia. Esophageal PEECS was defined by satisfying at least two of the following criteria: fever ≥ 37.8 °C, leukocytosis ≥ 10,800/mm3, and localized chest pain ≥ 5/10 points as assessed on a numeric rating scale within 24 h after ESD. Significant factors associated with PEECS were determined by regression analysis. RESULTS: PEECS was recorded in 98 of 202 (48.5%) patients. Patients with PEECS exhibited a larger tumor size (25.0 vs. 17.0 mm, P = 0.002), longer procedure (40.0 vs. 29.5 min, P = 0.021) and hemostasis times (5.0 vs. 3.5 min, P = 0.004), required greater submucosal injection volume (60.0 mL vs. 50.0 mL, P = 0.030), and had a lower rate of local steroid injection (4.1% vs. 12.5%, P = 0.029) than those without PEECS. Multivariate regression analysis revealed tumor size ≥ 17 mm (P = 0.047), procedure time ≥ 33 min (P = 0.027), and hemostasis time ≥ 5 min (P = 0.007) as risk factors for PEECS. In addition, local steroid injection was a significant negatively associated factor (P = 0.001). CONCLUSIONS: Patients with a large tumor, prolonged procedure and hemostasis times are at a high risk of PEECS occurrence. Further, local steroid injection is a negatively associated factor.

Harvesting of cyanobacteria and phosphorus by electrocoagulation-flocculation-flotation: Role of phosphorus precipitation in cell separations and organics destabilization.

A high level of phosphate triggers the excretion of algogenic organic matter (AOM) during algae blooming, leading to disinfection by-products (DBPs) formation. The presence of phosphate could impact cyanobacteria harvesting and AOM separations by electrocoagulation. This study aims to investigate the role of phosphate in cell separations and AOM destabilization by Al-based electrocoagulation-flocculation-flotation (EFF) for harvesting of cyanobacteria and phosphate. The Al-based EFF was conducted to harvest Microcystis aeruginosa (MA) with varied phosphate (0-10 mg/L) at 5 mA/cm2 and pH 8. Fluorescent organic fractions, molecular weight distributions, the properties of flocs and DBPs formation potential were fully investigated. The results showed that the EFF at a low level of phosphate (1 mg/L) effectively improves the harvesting of MA cells, phosphate and the reduction in dissolved organic matter (DOC) up to 99.5 %, 95 % and 50 %, respectively. However, the presence of concentrated phosphate (10 mg/L) alleviates cell harvesting and worsens AOM separations due to ineffective floc formation induced by the fast formation of inactive AlPO4 precipitates along with limited Al(OH)3. At such a condition, it worsens DBPs precursors minimization owing to AOM release from MA cells. The increase in the current density during EFF can compensate for cell harvesting efficiency even though at concentrated phosphate, but it further induces AOM release. It is concluded that Al-based EFF demonstrates an efficient harvesting of cyanobacteria, phosphorus and AOM separations from algae-laden water under phosphate impact.

Leachate treatment via electrocoagulation-coal-based powdered activated carbon process: Efficiencies, mechanisms, kinetics, and costs.

This study aims to improve COD, NH3-N, and turbidity removal from Bingöl's leachate using a single-reactor integrated electrocoagulation (EC)-coal-based powdered activated carbon (CBPAC) process under various experimental conditions. In the EC-CBPAC process, three stainless-steel cathodes and three aluminum electrodes were connected to the negative and positive terminals of the power supply, respectively. The initial concentrations in the leachate were 1044 mg O2/L for COD, 204 mg/L for NH3-N, and 57 NTU (or 71.25-mg (NH2)2H2SO4/L) for turbidity, respectively. After a 40-min EC-CBPAC process, with a CBPAC dosage of 5 g/L and pH of 5 for COD and turbidity, and 9.5 for NH3-N, the optimum removal efficiencies for COD, NH3-N, and turbidity were achieved at 92%, 40%, and 91%, respectively. When the EC process was applied without CBPAC under the same experimental conditions, the removal efficiencies of COD, NH3-N, and turbidity were 87%, 28%, and 54%, respectively. Before and after the EC-CBPAC process, the Brunauer-Emmett-Teller (BET) surface area, pore volume, and mean pore diameter of the CBPAC were found to be (888 m2/g, 0.498 cm3/g, and 22.28 Å) and (173 m2/g, 0.18 cm3/g, and 42.8 Å), respectively. The optimum pseudo-first-order (PFO) rate constants for COD, turbidity, and NH3-N were determined to be 3.15 × 10-2, 4.77 × 10-2, and 8.8 × 10-3 min-1, respectively. With the current density increasing from 15 to 25 mA/cm2, energy consumption, unit energy consumption, and total cost increased from 68.7 to 122.4 kWh/m3, 6.948 to 15.226 kWh/kg COD, and 0.85 to 1.838 $/kg COD, respectively. PRACTITIONER POINTS: EC-CBPAC process has greater COD, NH3-N, and turbidity removal efficiency than EC process. COD and turbidity achieved their optimum disposal efficiencies at 92% and 91%, respectively, at pH 5 The most efficient disposal efficiency for NH3-N was observed to be 40% at pH 9.5. EC-CBPAC process increased removal efficiencies for COD, NH3-N, and turbidity by 20%, 19%, and 38%, respectively, compared with EC alone. The turbidity, NH3-N, and COD disposal fitted PSO model due to high correlation values (R2 0.94-0.99).

Concurrent arsenic, fluoride, and hydrated silica removal from deep well water by electrocoagulation: Comparison of sacrificial anodes (Al, Fe, and Al-Fe).

Some studies have reported the removal of As (As) and fluoride (F-) using different sacrificial anodes; however, they have been tested with a synthetic solution in a batch system without hydrated silica (SiO2) interaction. Due to the above, concurrent removal of As, F-, and SiO2 from natural deep well water was evaluated (initial concentration: 35.5 µg L-1 As, 1.1 mg L-1F-, 147 mg L-1 SiO2, pH 8.6, and conductivity 1024 µS cm-1), by electrocoagulation (EC) process in continuous mode comparing three different configurations of sacrificial anodes (Al, Fe, and Al-Fe). EC was performed in a new reactor equipped with a small flow distributor and turbulence promoter at the entrance of the first channel to homogenize the flow. The best removal was found at j = 5 mA cm-2 and u = 1.3 cm s-1, obtaining arsenic residual concentrations (CAs) of 1.33, 0.45, and 0.77 µg L-1, fluoride residual concentration ( [Formula: see text] ) of 0.221, 0.495, and 0.622 mg L-1, and hydrated silica residual concentration ( [Formula: see text] ) of 21, 34, and 56 mg L-1, with costs of approximately 0.304, 0.198, and 0.228 USD m-3 for the Al, Fe and Al-Fe anodes, respectively. Al anode outperforms Fe and Al-Fe anodes in concurrently removing As, F- and SiO2. The residual concentrations of As and F- complied with the recommendations of the World Health Organization (WHO) (As < 10 µg L-1 and F- < 1 mg L-1). The spectroscopic analyses of the Al, Fe, and Al-Fe aggregates showed the formation of aluminosilicates, iron oxyhydroxides and oxides, and calcium and sodium silicates involved in removing As, F-, and SiO2. It is concluded that Al would serve as the most suitable sacrificial anode.

Risk factors and a nomogram for prediction of post-endoscopic submucosal dissection electrocoagulation syndrome for superficial colorectal lesions.

BACKGROUND: Post-endoscopic submucosal dissection electrocoagulation syndrome (PEECS) is an uncommon complication after colorectal endoscopic submucosal dissection (ESD). This study aimed to explore the risk factors of PEECS for superficial colorectal lesions based on the latest and consistent diagnostic criteria and to establish a predictive nomogram model. METHODS: This retrospective analysis included patients with superficial colorectal lesions who underwent endoscopic submucosal dissection (ESD) between June 2008 and December 2021 in our center. The independent risk factors of PEECS for superficial colorectal lesions were identified using least absolute shrinkage and selection operator (LASSO) logistic regression analysis, as well as univariate analysis and multivariate logistic regression, and derived predictive nomogram model was constructed. RESULTS: Among the 555 patients with superficial colorectal lesions enrolled, PEECS occurred in 45 (8.1%) patients. Multivariate logistic regression revealed that female sex (OR 3.94, P < 0.001), age > 50 years (OR 4.28, P = 0.02), injury to muscle layer (OR 10.38, P < 0.001), non-lifting sign (OR 2.20, P = 0.04) and inadequate bowel preparation (OR 5.61, P < 0.001) were independent risk factors of PEECS for superficial colorectal lesions. A predictive nomogram model was constructed based on the above five predictors. For this model, the area under the receiver operating characteristic (ROC) curve was 0.855, the calibration curve exhibited good consistency between the prediction and the actual observation, and the C-index was confirmed as 0.843 by bootstrap method. CONCLUSION: Female sex, age > 50 years, injury to muscle layer, non-lifting sign and inadequate bowel preparation were independent risk factors of PEECS for superficial colorectal lesions. The proposed nomogram could accurately predict the risk of PEECS for superficial colorectal lesions.

El humo del electrocauterio, el riesgo olvidado y minimizado de la cirugía / Smoke from electrocautery, the forgotten and minimized risk of surgery

Introducción. La nueva era de la cirugía es cada vez más dependiente de la tecnología, y un ejemplo de ello es el uso generalizado de electrocauterio como parte primordial de la práctica quirúrgica. El humo quirúrgico es un subproducto de la disección y la coagulación de los tejidos producidas por los equipos de energía, que representa múltiples riesgos potenciales para la salud del grupo quirúrgico, sin embargo, se han minimizado los peligros causados por la exposición de manera frecuente y acumulativa a este aerosol. Métodos. Se realizó un análisis crítico, desde una posición reflexiva de la información disponible, estableciendo los posibles riesgos relacionados con la exposición al humo quirúrgico. Discusión. Es visible la necesidad imperativa de establecer directrices nacionales, pautas normativas y recomendaciones estandarizadas para cumplir con las exigencias dadas por los sistemas de gestión en salud ocupacional y seguridad del trabajo, cuyo objetivo principal es hacer efectivo el uso de mascarillas quirúrgicas apropiadas, la implementación de programa de vigilancia epidemiológica ambiental en sala de cirugía, la priorización del uso constante de aspiradores y sistemas de evacuación, y la ejecución de programas educativos de sensibilización dirigidos al personal implicado. De igual manera, se abre la inquietud de la necesidad de nuevos estudios para definir con mayor precisión el peligro de este aerosol. Conclusión. Se recomienda de manera responsable utilizar todas las estrategias preventivas existentes para intervenir en salas de cirugía los riesgos minimizados y olvidados del humo quirúrgico.

Introduction. The new era of surgery is increasingly dependent on technology, and an example of this is the widespread use of electrocautery as a primary part of surgical practice. Surgical smoke is a byproduct of the dissection and coagulation of tissues produced by energy equipment, which represents multiple potential health risks for the surgical group; however, the dangers caused by cumulative exposure have been minimized. Methods. A critical analysis was carried out from a reflective position of the available information, establishing the possible risks related to exposure to surgical smoke. Discussion. The imperative need to establish national normative guidelines and standardized recommendations to comply with the demands given by the occupational health and work safety management systems, whose main objective is to make effective the use of appropriate surgical masks, implementation of environmental epidemiological surveillance program in the operating room, prioritizing the constant use of vacuum cleaners and evacuation systems, and carrying out educational awareness programs aimed at the personnel involved. Likewise, there is concern about the need for new studies to more precisely define the danger of this aerosol. Conclusion. It is recommended to responsibly use all existing preventive strategies to intervene in operating rooms to minimize the forgotten risks of surgical smoke.