Oxidation-reduction Potential Research Articles

A novel long short-term memory artificial neural network (LSTM)-based soft-sensor to monitor and forecast wastewater treatment performance

Commercial instrumentation for measurement of various wastewater treatment processes parameters is costly and time-consuming in wastewater treatment plants (WWTPs). Long short-term memory neural network (LSTM) based soft-sensors to monitor and forecast crucial performance parameters including chemical oxygen demand (COD), NH4+ and total nitrogen (TN), which was based on lower-cost sensors dataset (e.g., dissolved oxygen, oxidation reduction potential (ORP) and suspended solids), were developed for a two-staged anoxic-oxic (A/O) process for wastewater treatment. Pearson correlation analysis was conducted to identify the essential model input features before LSTM development. With optimization of look-back periods, the proposed LSTM-based soft-sensors outperformed multiple linear regression model (MLR)-based soft-sensors for prediction of influent COD, influent NH4+, effluent COD and effluent TN. It was supported by the lower mean absolute percentage error, lower root mean squared error and higher Pearson correlation for LSTM-based soft-sensors compared to those of MLR-based soft-sensors. The overall results indicated that LSTM-based soft-sensors can achieve automated high-resolution measurement and effectively forecast the crucial performance of biological wastewater treatment, potentially lowering the capital cost for sensor installation in WWTPs.

Indigo reduction by using microorganism: Comparison of reducing power between Dietzia sp. KDB1 and yeast (Saccharomyces cerevisiae)

AbstractThis study aims to develop microbial indigo reduction by comparing the reducing power between Dietzia sp. KDB1 and yeast (Saccharomyces cerevisiae) at some reduction conditions. Oxidation–reduction potential (ORP), colour strength (K/S), and fluorescence intensity (FI) were applied to evaluate the reduction level as a function of microorganism concentration, pH, and glucose addition at 30°C. For both of the microbial systems, ORP decreased further −20 mV and K/S increased more than two by adding glucose. The reduction level became higher slightly by adding glucose, which played a role of metabolite in both of the reduction systems. Overall, reduction level of the yeast system was about a half of KDB1 system at the same reduction condition of 45 mL volume, 15 g/L natural indigo, 6 g/L reducing agents, pH 10.0, 30°C and glucose added.

Nutritional Supplementation and Enhanced Antioxidant Function by Dietary Intake of Selenoneine and Other Selenium Compounds in Red Seabream Pagrus major

Selenoneine, 2-selenyl-Nα, Nα, Nα-trimethyl-L-histidine, is the major organic selenium compound in marine fish. To characterize biological antioxidant function of selenoneine in fish, the accumulation of selenoneine and other selenium compounds, i. e., sodium selenite and selenomethionine, in the muscle and other tissues of red seabream. We reared red seabream by feeding of 1% dry pellet containing of sodium selenite, selenomethionine, or selenoneine of body weight twice a day for 4 weeks. After that, we replaced to 1% of normal commercial dry pellet of body weight twice a day for 1 week from the selenium supplementation, and tissue distribution of total selenium was determined. Selenium supplementation with selenoneine, selenomethionine, and sodium selenite enhanced selenium accumulation in the white muscle, kidney, and hepatopancreas in comparison with the control group. By the dietary intake of selenoneine, total selenium concentrations were increased in the white muscle, heart, kidney, spleen, hepatopancreas, brain, and blood cells in a dose-dependent manner during the trials after 2 weeks. Dietary intake of selenoneine as well as sodium selenite and selenomethionine reduced oxidation–reduction potential (ORP). Selenoneine concentrations in the white muscle and blood cells were accumulated for 4 weeks by the selenoneine intake, whereas selenoneine concentration was not elevated by the intake of selenomethionine and sodium selenite, suggesting that tissue selenoneine levels might be derived from only selenoneine-containing diet. The uptake factor of selenoneine from the artificial feed containing selenoneine was calculated to be 0.0062 in the white muscle and 4.0 in the blood. The half-life of total selenium in the blood cells and white muscle were estimated to be 60 days in the white muscle and 30 days in the blood.

Effects of complex sulphur substrates on sludge bioleaching to improve heavy metal removal and microbial community diversity

In this study, H2S was used as a partial replacement nutrient substrate for sludge bioleaching. The effects of different combinations of H2S/sludge load and monomeric sulphur on heavy metal removal and microbial communities were investigated. Changes in pH, oxidation-reduction potential (ORP), SO42− concentration, heavy metal removal, and the content of heavy metal states during bioleaching were investigated, and community diversity analysis was performed. Daily introduction of H2S three times (at an interval of 8 h) at a gas flow rate of 2 ml/min and an H2S/sludge load of 15 ml/L with 5 g/L FeSO4·7H2O and 2 g/L monomeric sulphur as a nutrient substrate significantly accelerated both the bioleaching process and the pH drop in the sludge system, promoted the production of SO42−, and maintained a higher redox potential. The combination of H2S and monomeric sulphur had a significant effect on the leaching of heavy metals. Compared with the experimental group containing only H2S or monomeric sulphur, the removal rates of Zn, Ni, Pb, and Cr increased by 4.63%/13.8%, 8.5%/20.07%, 3.84%/9.5%, and 4.24%/8.02% respectively, while promoting the transformation of various heavy metal states to labile states, improving heavy metal stability, and reducing sludge ecotoxicity. High-throughput sequencing analysis showed that introducing the H2S gaseous matrix accelerated the decreasing trend of species number, bacterial abundance, and community diversity in the sludge system, promoting Proteobacteria as the dominant phylum, Acidithiobacillus, Metallibacterium, and Thiomonas as the dominant genera, and improving the bioleaching treatment effect.

Efficient treatment of bio-contaminated wastewater using plasma technology for its reuse in sustainable agriculture

Water-related crisis represents one of the significant challenges of the rapidly growing world population. This study demonstrates an example of the novel technology of Non-Thermal Plasma (NTP) wastewater treatment for its sustainable recovery and reuse in agriculture. NTP treatment of wastewater not only causes microbial decontamination but produces Reactive Oxygen and Nitrogen Species (RONS), which can consequently improve seed germination and plant growth. We investigated the effects of the new Fountain Dielectric Barrier Discharge air plasma reactor for the treatment of bulk quantity water contaminated by Staphylococcus epidermidis or Escherichia coli bacteria. Then, employing the treated water for barley seed germination showed >20% enhancement compared to using tap water. The inactivation of bacteria in water was determined in dependence on pH, Oxidation-Reduction Potential, and correlated with chemical RONS produced in the water (hydrogen peroxide, nitrites, and especially nitrates). By utilizing the Responses Surface Methodology, we identified the optimal plasma treatment time per litre required for efficient RONS production and bactericidal effect in the wastewater treatment, which was linearly scalable with water volume. After the optimum plasma treatment time, a sharp drop in pH, and the concentrations of nitrites and hydrogen peroxide were observed, which is related to the peroxynitrite formation leading to the significant bacterial reduction up to 7-log.

Designing a novel portable oxidation–reduction potential and microbial fuel cell‐based sensor to monitor microbial growth

AbstractThis study demonstrates the potential application of a portable 3D‐printed sensor to monitor microbial growth during soil bioremediation. Bacillus subtilis, a commonly found soil microorganism, is used to evaluate its growth characteristics. The integration of real‐time oxidation–reduction potential (ORP) reading and voltage output allows for a better illustration of microbial growth, with a focus on the mid‐exponential growth phase. This new technology can potentially increase the efficiency of soil bioremediation techniques by providing a better understanding of the microbial interactions and growth patterns involved.

Improving soil aquifer treatment efficiency using air injection into the subsurface

Abstract. Soil aquifer treatment (SAT) is an effective and sustainable technology for wastewater or stormwater treatment, storage, and reuse. During SAT, the vadose zone acts as a pseudo-reactor in which physical and biochemical processes are utilized to improve the infiltrated-water quality. Dissolved oxygen (DO) is necessary for aerobic microbial oxidation of carbon and nitrogen species in the effluent. Therefore, to enhance aeration, SAT is generally operated in flooding and drying cycles. While long drying periods (DPs) lead to better oxidizing conditions and improve water quality, they reduce recharge volumes. As the population grows, the quantity of effluent directed to SAT sites increases, and increasing recharge volumes become a concern and often a limiting factor for SAT usage. In this study, direct subsurface air injection SAT (Air-SAT) was tested as an alternative to long-DP operation. Six long-column experiments were conducted (2 m column) that aimed to examine the effect of air injection on the soil's water content, oxidation–reduction potential (ORP), DO concentrations, infiltrated amounts, and ultimate outflow quality. In addition to basic parameters, such as dissolved organic C (DOC) and N species, the effluent quality analysis also included an examination of three emerging water contaminants: ibuprofen, carbamazepine, and 1H-benzotriazole. Pulsed-air-injection experiments were conducted during continuous flooding using different operation modes (i.e., air pulse durations, frequencies, and airflow rates). Our results show that Air-SAT operation doubled the time during which infiltration was possible (i.e., the infiltration was continuous with no downtime) and allowed up to a 46 % higher mean infiltration rate in some cases. As a result, the infiltration volumes in the Air-SAT modes were 47 %–203 % higher than conventional flooding–drying operation (FDO). A longer air pulse duration (60 min vs. 8 min) and higher airflow rate (∼2 L min−1 vs. ∼1 L min−1) led to a higher mean infiltration rate, whereas a high pulse frequency (4.5 h−1) led to a lower mean infiltration rate compared with low-frequency operation (24 h−1). Air injection also allowed good recovery of the ORP and DO levels in the soil, especially in the high-frequency Air-SAT experiments, where steady aerobic conditions were maintained during most of the flooding. Consequently, the mean DOC, total Kjeldahl N (TKN), and ibuprofen removal values in these experiments were up to 9 %, 40 %, and 65 % higher than those with FDO, respectively. However, high-frequency Air-SAT during continuous flooding also led to significant deterioration of the mean infiltration rate, probably due to enhanced biological clogging. Hence, it may be more feasible and beneficial to combine it with conventional FDO, allowing a steady infiltration rate and increased recharge volumes while sustaining high effluent quality. While these results still need to be verified at full scale, they highlight the possibility of using air injection to minimize the DP length and alleviate the pressure on existing SAT sites.

Characterization of 20 Oenological Tannins from Different Botanical Origins for Formulation of Blends with Redox Potential Tuning Ability in Model Wine Solution.

Twenty oenotannins from different botanical origins were studied in model wine solution (1 g/L, 12% ethanol, pH 3.5). An original device was created for measuring Oxidation-Reduction potential (ORp) of the solutions at 20 °C in strict anoxic condition by the electrochemical method of the platinum electrode zero-current potential. Reactivity against proteins and antioxidant properties were related to the chemical structure and, consequently, to the botanical origin of the oenotannins. The highest turbidity after BSA addition (ΔNTU > 1000) values were measured for the gallic hydrolysable tannins. The ORp versus standard hydrogen electrode ranged from 420 to 260 mV. The ellagitannins had the highest antioxidant power (AP%), followed by condensed tannins and gallotannins, highlighting a correlation with the phenolic profile. Based on these findings, two formulations were prepared as a blend of some of the tested oenotannins, with the ability to increase (MIX1) and decrease (MIX2) the ORp of the model wine.

Microbial electrolysis cell simultaneously enhancing methanization and reducing hydrogen sulfide production in anaerobic digestion of sewage sludge

The effects of microbial electrolysis cells (MECs) at three applied voltages (0.8, 1.3, and 1.6 V) on simultaneously enhancing methanization and reducing hydrogen sulfide (H2S) production in the anaerobic digestion (AD) of sewage sludge were studied. The results showed that the MECs at 1.3 V and 1.6 V simultaneously enhanced the methane production by 57.02 and 12.70% and organic matter removal by 38.77 and 11.13%, and reduced H2S production by 94.8 and 98.2%, respectively. MECs at 1.3 V and 1.6 V created a micro-aerobic conditions for the digesters with oxidation-reduction potential as −178∼-232 mv, which enhanced methanization and reduced H2S production. Sulfur reduction, H2S and elemental sulfur oxidation occurred simultaneously in the ADs at 1.3 V and 1.6 V. The relative abundances of sulfur-oxidizing bacteria increased from 0.11% to 0.42% and those of sulfur-reducing bacteria decreased from 1.24% to 0.33% when the applied voltage of MEC increased from 0 V to 1.6 V. Hydrogen produced by electrolysis enhanced the abundance of Methanobacterium and changed the methanogenesis pathway.

Smart capsule for monitoring inflammation profile throughout the gastrointestinal tract

Inflammatory bowel disease (IBD) has become alarmingly prevalent in the last two decades affecting 6.8 million people worldwide with a starkly high relapse rate of 40% within 1 year of remission. Existing visual endoscopy techniques rely on subjective assessment of images that are error-prone and insufficient indicators of early-stage IBD, rendering them unsuitable for frequent and quantitative monitoring of gastrointestinal health necessary for detecting regular relapses in IBD patients. To address these limitations, we have implemented a miniaturized smart capsule (2.2 cm × 11 mm) that allows monitoring reactive oxygen species (ROS) levels as a biomarker of inflammation for quantitative and frequent profiling of inflammatory lesions throughout the gastrointestinal tract. The capsule is composed of a pH and oxidation reduction potential (ORP) sensor to track the capsule's location and ROS levels throughout the gastrointestinal tract, respectively, and an optimized electronic interface for wireless sensing and data communication. The designed sensors provided a linear and stable performance within the physiologically relevant range of the GI tract (pH: 1–8 and ORP: −500 to +500 mV). Additionally, systematic design optimization of the wireless interface electronics offered an efficient sampling rate of 10 ms for long-running measurements up to 48 h for a complete evaluation of the entire gastrointestinal tract. As a proof-of-concept, the capsule the capsule's performance in detecting inflammation risks was validated by conducting tests on in vitro cell culture conditions, simulating healthy and inflamed gut-like environments. The capsule presented here achieves a new milestone in addressing the emerging need for smart ingestible electronics for better diagnosis and treatment of digestive diseases.

A Smart System for Environmental Parameter Monitoring in Underwater Archaeological Sites

In this paper, we present a prototype for the remote monitoring of underwater archaeological sites. The system aims to provide autonomous and real-time data collection from environmental probes and also includes biofouling detection based on image processing. The monitoring system is equipped with sensors to measure various parameters of interest, including temperature, pH, conductivity, dissolved oxygen, and oxidation-reduction potential. To detect biofouling, a camera is integrated into the system, and an analysis is performed on the captured images utilizing indices such as the Normalized Difference Vegetation Index (NDVI) and the PYM method. The system consists of a subsea node placed near the monitoring site, connected to a surface buoy through an umbilical cable. The surface buoy contains an LTE router for data transmission to a remote web platform for data storage and visualization. The hardware of the underwater node includes an embedded computer, responsible for providing functionalities for image processing and interfacing with the web platform, and a micro-controller board to read the sensor measurements. The developed remote monitoring system has been tested in a marine environment and offers a comprehensive solution for long-term environmental parameter analysis, biofouling detection, and real-time data access. It holds great potential for applications in marine research, environmental monitoring, and ecosystem studies.

Assessment of suitability and lipid quality indicators of lamb meat of Polish native breeds

Abstract The aim of our study was to evaluate the technological (pH, water holding capacity, cooking loss, oxidation-reduction potential, water activity, color parameters, and microbiological purity) and nutritional suitability of the meat of selected lamb breeds by analyzing the indicators (fatty acid profile, fat nutritional indices, lipid oxidation, basic meat composition) that determine the quality of lipids present in the meat. A comparative analysis of meat from native Polish breeds Uhruska, Świniarka, and Wrzosówka showed that these breeds are characterized by high-quality meat. The chemical composition of meat did not significantly differ between the studied breeds. However, the fatty acid composition and atherogenicity and thrombogenicity indices of meat differed significantly between the breeds with the meat of Wrzosówka lambs having a distinct advantage and the most significant potential to protect against cardiovascular problems. Furthermore, the meat of Wrzosówka breed had color parameters that are most desired by consumers. The results presented here are of practical importance as combining meat from different breeds of lambs can allow achieving high product quality. The meat of Wrzosówka breed can be successfully used for producing such products and can serve as flagship meat for export to other European and global markets.

A multi-model data fusion methodology for reservoir water quality based on machine learning algorithms and bayesian maximum entropy

A major concern in the management of reservoirs is water quality because of the negative consequences it has on both environment and human life. Artificial Intelligence (AI) concept produces a reliable framework to recognize complicated and non-linear correlations between input and output data. Although various machine learning (ML) algorithms in recent studies were employed to predict water quality variables, the existing literature lacks exploring the combination of these algorithms, which has the potential to significantly amplify the outcomes achieved by individual models. Thus, the current study aims to bridge this knowledge gap by evaluating the precision of Random Forest Regression (RFR), Support Vector Regression, Multilayer Perceptron (MLP), and Bayesian Maximum Entropy-based Fusion (BMEF) models to estimate such water quality variables as dissolved oxygen (DO) and chlorophyll-a (Chl-a). The comparisons were conducted in two primary stages: (1) a comparison of the outcomes of different ML algorithms with each other, and (2) comparing the ML algorithms' findings with that of the BMEF model, which considers uncertainty. These comparisons were evaluated using robust statistical measures, and, finally, to indicate the utility and efficacy of the newly introduced framework, it was efficiently utilized in Wadi Dayqah Dam, which is situated in Oman. The findings indicated that, throughout both training and testing phases, the BMEF model outperformed individual machine learning models, namely MLP, RFR, and SVR by 5%, 26%, and 10%, respectively, when R2 and Chl-a are considered as evaluation index and water quality variables, respectively. Additionally, as the individual ML models are not capable of predicting electrical conductivity and oxidation-reduction potential efficiently, the BMEF model leads to better results by R2=0.89, which outperforms MLP (R2=0.81), RFR (R2=0.79), and SVR (R2=0.62) for oxidation-reduction potential. Regarding the study limits of the present study, spatio-temporal data should be collected over a long time to increase the data frequency and reduce the uncertainty related to climate variability.

Effects of soil habitat changes on antibiotic resistance genes and related microbiomes in paddy fields

The changes of paddy soil habitat profoundly affect the structure and function of soil microorganisms, but how this process drives the growth and spread of manure- derived antibiotic resistance genes (ARGs) after entering the soil is unclear. Herein, this study explored the environmental fate and behavior of various ARGs in the paddy soil during rice growth period. Results showed that most ARG abundances in flooded soil was lower than that in non-flooded soil during rice growth (decreased by 33.4 %). And soil dry-wet alternation altered microbial community structure in paddy field (P < 0.05), showing that Actinobacteria and Firmicutes increased in proportion under non-flooded conditions, and Chloroflexi, Proteobacteria and Acidobacteria evolved into the dominant groups in flooded soil. Meanwhile, the correlation between ARGs and bacterial communities was stronger than that with mobile genetic elements (MGEs) in both flooded and non-flooded paddy soils. Furthermore, soil properties, especially oxidation reduction potential (ORP), were proved to be an essential factor in regulating the variability of ARGs in the whole rice growth stage by structural equation model, with a direct influence (λ = 0.38, P < 0.05), following by similar effects of bacterial communities and MGEs (λ = 0.36, P < 0.05; λ = 0.29, P < 0.05). This study demonstrated that soil dry-wet alternation effectively reduced the proliferation and dissemination of most ARGs in paddy fields, providing a novel agronomic measure for pollution control of antibiotic resistance in farmland ecosystem.

Evaluation of Groundwater Quality and Suitability for Irrigation Purposes and Human Consumption in Saudi Arabia

Studying groundwater quality is crucial for ensuring its safety because it is widely used for drinking and for domestic, agricultural, and industrial purposes. Owing to the lack of surface water in the Tabuk area of Saudi Arabia, here groundwater wells are one of the primary sources of water for drinking, agriculture, and industry. Groundwater quality is determined by the aquifer characteristics of the regional geology, and it is extensively influenced by both natural and anthropogenic activities. To understand the geochemical evolution and assess the suitability of groundwater for irrigation, major ion geochemistry was utilized to characterize the chemical composition of groundwater in the Tabuk area, which is considered a semiarid plateau region. Depending on its mineral composition, irrigation water’s quality reflects how it affects plants and soil. In total, 80 groundwater samples have been collected and analyzed in laboratory for major cations and anions. Temperature, alkalinity (ALK), pH, total dissolved solids (TDS), electric conductivity (EC), total hardness (TH), oxidation reduction potential (ORP), and cation and anion concentrations were measured. Water chemistry classification was carried out by using a Piper diagram and a Gibbs diagram. In the current study, statistical methods, combined with geochemical modeling and conventional plots, have been used to investigate groundwater and related geochemical processes in the Tabuk area of Saudi Arabia. Applications and calculations of hydrogeochemical parameters, specifically SAR, RSC, PI, CR, MH, Na%, KR, and HI, showed that 92.5% of the collected groundwater well samples are suitable for drinking and irrigation purposes after treatment processes.

P-275 Oxidation reduction potential (ORP) levels in blood plasma could represent the ORP status in follicular fluid from oocyte donors and patients

Abstract Study question Does the evaluation of oxidation-reduction potential (ORP) levels in blood plasma from subfertile patients and oocyte donors represents the ORP status in follicular fluid? Summary answer ORP levels in blood plasma from oocyte donors and sub fertile patients could be an indicator of oxidative stress in follicular fluid What is known already Oxidation-reduction potential (ORP) measurement of seminal plasma is one method to diagnose oxidative stress in male patients, which can help physician to recommend antioxidants administration when it is elevated. Seminal plasma is easily accessible by masturbation. An empirical analogue for semen could be follicular fluid (FF). Unfortunately, it is very difficult to access to FF, unless a surgical procedure is performed. Hence, it is necessary to find indirect parameters to evaluate the ORP status in FF. Since blood plasma (BP) circulation provides antioxidants to the FF, we studied the BP ORP measurement to indirectly determine ORP levels in FF. Study design, size, duration Prospective study conducted at CITMER, Mexico from December 2022 to January 2023. We included under informed consent 15 oocyte donors (age 26.8 ± 4.06 years old) and 55 patients (age 35.2 ± 4.8 years old) undergoing IVF/ICSI. Participants/materials, setting, methods ORP levels in BP and FF from dominant follicles were measured at the same time of oocyte collection with MiOXSYS system. Oocytes were inseminated and zygotes were cultured until blastocysts stage. We calculated correlation of a) ORP levels in FF vs BP, b) ORP of FF and BP vs number of retrieved oocytes, c) ORP of FF and BP vs number of fertilized oocytes, d) ORP of FF and BP vs number of blastocysts Main results and the role of chance A total of 172 oocytes from oocyte donors were collected. After fertilization check, 135 zygotes (78%) were observed. A total number of 55 blastocysts (31%) were observed at day 5 + day 6. For patients, a total of 550 oocytes were collected, 360 zygotes were observed (65%) and 164 blastocysts at day 5 + day 6 were obtained (45%). The correlation between ORP levels from FF and BP for oocyte donors was 0.90 and 0.51 for patients. The overall ORP levels in FF and BP in patients were 136.2 ± 14.9 mV and 148.3 ± 15.97 mV, respectively. For oocyte donors, ORP levels in FF and BP were 160.3 ± 13.8 mV and 170.28 ± 17.67mV, respectively. There was a mild correlation of ORP levels in BP with numbers of oocytes retrieved (r = 0.25). The correlation of BP ORP with oocyte fertilization was 0.24 in patients with autologous oocyte utilization. The mean ORP levels of FF were 136.2 ± 14.9 mV, versus a mean ORP of 148.3 ± 15.97 mV in BP. The FF ORP levels between 100-150 mV [LRD1] were moderately correlated and predictive of blastocyst development [LRD2]. For donor oocytes there was a weak negative correlation [LRD3] of FF ORP with oocyte fertilization (-0.06) and a weak negative correlation for blastocyst formation was found (-0.18). Limitations, reasons for caution The MiOXSYS System ( Careous Biotechnology, Lituania) is a device calibrated to measure ORP levels in seminal plasma but not to measure ORP levels in FF nor BP. The number of analyzed data should be increased. Wider implications of the findings According to this study, the use of blood plasma to surrogate the measurements of ORP levels in follicular fluid could represent a further strategy to include female patients to be treated by antioxidants before an IVF treatment. Trial registration number None

P-033 Impact of the sperm reactive oxygen species on Intrauterine Insemination outcome

Abstract Study question Does sperm reactive oxygen species values affect the pregnancy rate after Intrauterine Insemination (IUI)? Summary answer Sperm reactive oxygen species values affect pregnancy rate and can be used as a predictive marker for IUI outcome. What is known already Oxidative stress resulting from excessive production of reactive oxygen species (ROS) can profoundly affect the sperm and subsequent functional sperm integrity. Diagnostics to measure semen oxidative stress have been added to the 6th edition of the WHO laboratory manual for examining and processing of human semen, under advanced examinations. Although a semen analysis has classically been used as the gold standard for determining a man’s fertility, basic sperm analysis alone cannot accurately predict infertility since between 6 and 27 % of men with normal semen parameters are infertile. Determination of oxidative stress in diagnosing infertility may contribute to better outcomes. Study design, size, duration This study was based on semen analyses of 50 male patients whose samples were used for IUI treatment between November 2022 and January 2023. The oxidation-reduction potential was measured using novel galvanostat-based technology, the MiOXSYS System. Briefly, 30 μL of liquefied semen at room temperature were applied to the MiOXSYS sensor. Both absolute ORP (mV) and normalized sORP values ( mV/10 6 sperm/ml) based on sperm concentration were calculated. Participants/materials, setting, methods Sperm analysis were performed according to the WHO laboratory manual sperm criteria (Sixth edition 2021). All participants followed a period of 3–5 days of sexual abstinence and had a diagnosis of unexplained infertility (normozoospermia). Ovarian stimulation for IUI cycle was initiated on the 5th day of menstruation by using recombinant gonadotropins. Clinical pregnancy was determined based on the Beta-hCG values. For statistical comparison between group values the Mann-Whitney U test was used. Main results and the role of chance According to the guidelines of the World Health Organization, all participants included in the study had normal BMI (21.85±3.80 kg/m2). The average age of the female patients included in the study was 33.9 ± 3.1 years while the average age of the male patients was 37.8 ± 4.8 years. Out of the 50 patients, 32% (N = 16) got pregnant. For the study propose sperm ORP and sORP values were compared between patients based on the pregnancy outcome. Statistical analysis showed a significant difference in ORP values. Patients with a positive pregnancy outcome after IUI had a lower ORP value compared to patients where IUI was not successful [25.65 [6.7-52.6] mV vs. 40.2 [6.3-109.8] mV, respectively, p = 0.02]. Additionally, normalized values according to the sperm concentration (sORP) were also significantly different between those groups [ 0.37(0.17-1.44) mV/10 6 sperm/ml vs. 0.88(0.13-20.81) mV/10 6 sperm/ml, respectively p = 0.006]. Due to the above-mentioned significant difference logistic regression analysis were performed, and the obtained results confirm that sperm ORP (p = 0.02) as well sORP (p = 0.016) significantly affects the pregnancy rate after the IUI procedure. Limitations, reasons for caution The limitation of the presented study was a relatively small patient cohort. Additionally, pregnancy was determined based on the beta hCG values, therefore future research should link ORP values and live birth rate as well. Wider implications of the findings In the present study suggests ORP as an additional parameter with diagnostic value to identify the best therapeutic approach concerning IUI in couples that show minimal or no impairments of the WHO semen parameter. Trial registration number not applicable

A New Slurry for Photocatalysis-Assisted Chemical Mechanical Polishing of Monocrystal Diamond

Diamond needs to have a perfectly smooth surface due to the growing requirements in the fields of electronic semiconductors, optical windows and high-fidelity loudspeakers. However, the polishing of diamonds is highly challenging due to their exceptional hardness and chemical stability. In this study, a new polishing slurry is prepared for the proposed photocatalysis-assisted chemical mechanical polishing (PCMP) approach to obtain an ultra-smooth surface for large-area diamond. The analyses and experimental findings revealed the significance of the photocatalyst, abrasive, electron capture agent and pH regulator as essential components of the PCMP slurry. TiO2 with a 5 nm pore size and P25 TiO2 possess improved photocatalysis efficiency. Moreover, diamond removal is smooth under the acidic environment of H3PO4 due to the high oxidation–reduction potential (ORP) of the slurry, and, during the methyl orange test, P25 TiO2 exhibits reasonable photocatalytic effects. Moreover, in 8 h, a smooth surface free of mechanical scratches can be obtained by reducing the surface roughness from Ra 33.6 nm to Ra 2.6 nm.

Freezing degradation of the anticonvulsant oxcarbazepine by bromate in water ice under sunlight irradiation

Ice plays a crucial role in contaminant transformation in seasonally ice-covered waters. In this study, the characteristics and mechanisms of an emerging contaminant oxcarbazepine (OXC) degradation by a disinfection by-product bromate (BrO3–) in ice were explored via combined experiments and theoretical calculations. Results showed that 74.0 % and 86.4 % of OXC was degraded by BrO3– in ice after 140 min in dark and 120 min under solar irradiation, respectively, while the reaction was negligible in water. The oxidation-reduction potential of BrO3– solution at 1000 μmol L−1 was 56.9 % higher than that at 50 μmol L−1. The oxidation-reduction potential of BrO3– solution at pH 2 was 14.8 %–109.5 % higher than those at other pH values. Enhanced OXC degradation by BrO3– in ice could be attributed to increased BrO3– oxidation capacity resulting from locally elevated BrO3– and H+ concentrations. Hypobromous acid (HOBr), •OH, and Br• generated by direct photolysis under solar irradiation further promoted the OXC degradation in ice. Br• formed by the direct photolysis of accumulated HOBr under solar irradiation caused the generation of bromine-containing degradation products. Bromine-containing degradation products possessed higher potential toxicities, which could contribute to increase the secondary pollution of water environment.

Microbial community dynamics in a feedback-redox controlled bioreactor process that enabled sequential selenate, nitrate and sulfate removal, and elemental selenium recovery

Oxidation reduction potential (ORP) feedback-control by ethanol-dosing was recently proved effective in facilitating a two-stage fluidized bed reactor (FBR) process to remove selenate, nitrate, and sulfate from wastewater, and recover high-purity elemental Se without the formation of carcinogenic SeS. However, further optimization requires knowledge on the relationship between microbial community composition and process performance. Here, changes of microbial communities during the reduction of selenate and nitrate in the first FBR (FBR1) under various ORP conditions (−240 to −520 mV vs. Ag/AgCl), sulfate reduction in subsquent FBR (FBR2) and sulfide oxidation in sulfide oxidation reactor (SOR) were examined. Based on 16S rRNA gene sequencing, high ORP (stage i without sulfate: >−360 mV; stage ii with sulfate: >−440 mV) and elevated sulfate at ORP ≤ −480 mV (stage iii) in FBR1 altered the microbial communities both on fluidized carrier and bulk liquor. Selenate reducers (Geoalkalibacter and Geovibrio genera) were impacted at ORP > −360 mV (stage i) or >−440 mV (stage ii), when selenate removal in FBR1 declined. However, nitrate reducers (Caenispirillum and Paracoccus genera) were not affected in the FBR1, and facilitated ~100 % nitrate removal. At ORP ≤ −480 mV, selenate reducers were readily enriched in FBR1. In the FBR2, the major sulfate reducing genera were Desulfomicrobium, Desulfovibrio and Desulfuromonas, whereas the dominant sulfide-oxidating genera in SOR were Paracoccus, Thiobacillus and Acholeplasma. This study suggested that both nitrate- and selenate-reducing communities could remain active under elevated sulfate concentrations, enabling sequential oxyanions removal and elemental Se recovery from wastewater.