Final Water Quality Research Articles

Isolation and assessment of highly sucrose-tolerant yeast strains for honey processing factory's effluent treatment.

Wastewater from many food and beverage manufacturers is enriched in organic content, and it must therefore be treated before being discharged to comply with the strict environmental regulations to protect the final water quality. Concretely, the honey processing wastewater, that remains in holding tanks until is disposal, is a rich source of sugars and this high level of organic material will degrade the water quality if not treated properly provoking an imbalance in the ecosystem. There are different strategies for an adequate treatment of this wastewater effluent to obtain a sustainable usage. One of the techniques that is more cost-effective and environmental friendlier than chemical procedures used for water remediation, is the use of microorganisms (including algae, fungi, yeasts, or bacteria). Given that they are fast-growing, robust, and metabolically diverse, yeast strains are often used for wastewater treatment. In this work, we have studied the potential for bioremediation of non Saccharomyces yeast isolated from a honey processing wastewater generated by an Argentine exporting company. The inoculation of these yeast strains to the existing flora in the honey wastewater yielded a better improvement in the treatment yield. These results suggest that these strains display a promising role could for optimizing bioremediation strategies in industrial wastewater treatment processes.

Evaluating groundwater vulnerability and assessing its quality for sustainable management

Areas with a dry climate constitute about 15% of the Earth's surface, so groundwater can be considered a safe alternative available for people who are living in these areas. Groundwater has special advantages compared to surface water in terms of spatiotemporal presence, high stability, easy access, and often of high quality and capable of resisting pollution and could be the alternative to solve the problem of water shortage.The current study evaluated Irrigation Water Quality Indices (WQIs) as well as the predicting of GIS maps to evaluate groundwater resources for agricultural uses in Al-Najaf city. 24 samples were taken from the existing wells and examined for the characteristics relating the groundwater quality. Total hardness (TH), Sodium Adsorption Ratio (SAR), Residual Sodium Carbonate (RSC), Soluble Sodium Percentage (SSP), Magnesium Hazard (MH), Permeability Index (PI), and Kelley's Index (KI) were among the irrigation indices that were assessed and evaluated. The results showed that 95.8% of sites fall within the region of extremely high salinity danger /low sodium, and 4.2% of sites fall onto the medium sodium water class, Concerning SSP and RSC all samples are considered of good quality, 95.8% of samples are suitable for irrigation based on Kelly's Ratio index, while only 4.2% regarded unsuitable. The final WQIs values were exported to the ArcMap software to create the final study area's water quality indices maps. Conducting spatial variability of groundwater quality is essential for making reliable groundwater quality interpretations and for making accurate predictions of quality at any particular site, there must be a continuous salinity and contaminants concentrations checking up calculations in case there were a need for groundwater desalination process.

Formation, speciation, and temporal variability of DBPs in drinking water distribution systems in the context of ASR operations and extended storage periods

As climate change induces changes in water quality and available water quantity of drinking water supply sources, the final product water quality changes in terms of trace organics including disinfection byproducts (DBPs) formed during water treatment. In this study, the seasonal variability and speciation of DBPs across nine sample sites within a drinking water distribution system serving ∼400k people over a one-year period was investigated considering the governing parameters of water quality and treatment/transport/storage of finished water. The system considered treats surface water from a river and practices aquifer storage and recovery to address seasons water availability changes. Eighty-eight (88) sample sets were collected and held for 6-months in the laboratory to simulate extended storage scenarios associated with ASR operations, and each was analyzed at 9 different timesteps for concentration and speciation of chlorinated DBPs. Samples from groundwater influenced sites exhibited significantly lower total organic carbon (TOC) compared to other sites from the river source, and also were observed to have the lowest DBP formation. Three sites exceeded the Maximum Contaminant Level (MCL) for four total trihalomethanes (THM4) within 30–60 days of storage. Chloroform was the predominant THM4 species, even in groundwater-influenced locations, whereas di- and tri-chloroacetic acid (DCA and TCA) were the most prevalent haloacetic acids (HAA5). Extended water age at one site, coupled with low initial chlorine concentrations exhibited higher initial THM4 concentrations and flat DBP formation curves. The study results provide new insights into DBP occurrence and fate in drinking water distribution systems which consider water storage such as in ASR.

Capabilities of Microbial Consortia from Disparate Environment Matrices in the Decomposition of Nature Organic Matter by Biofiltration

Dissolved organic matter (DOM) plays a pivotal role in drinking water treatment, influencing the performance of unit processes and final water quality (e.g. disinfection byproduct risk). Biofiltration is an effective method of reducing DOM, but currently lacks a comprehensive appreciation of the association between microbial profiles and biofiltration performance. In this study, bench-scale biofiltration units inoculated with microbial consortia from river and soil matrices were operated successively for comparing their efficacy in terms of DOM removal. The results showed that biofiltration units receiving soil microbes were significantly superior (p < 0.05) to those receiving river inoculated microbes in terms of decomposing DOM recalcitrant fractions and reducing DBP formation potential, resulting in DOC and DBP precursor removals of up to 58.4 % and 87.9 %, respectively. Characterization of the taxonomic composition revealed that differences in the microbial assembly of the two biofilter groups were subject to deterministic rather than stochastic factors. Furthermore, more complicated interspecific relationships and niche structures in soil inoculated biofilters were deciphered by co-occurrence network, providing a plausible profile on a taxonomic division of labor in DOM stepwise degradation. Accordingly, the contribution of microbial compositions was found to be of greater importance than the GAC mass and biomass attached to the media. Thus, this study has advanced the understanding of microbial-mediated DOM decomposition in biofiltration, and also provided a promising strategy for enhancing the process for water use via developing appropriate engineered consortia of bacteria.

Safety of Tap Water in Terms of Changes in Physical, Chemical, and Biological Stability

Monitoring the quality of tap water in the distribution system and the ability to estimate the risk of losing its sanitary safety is an important aspect of managing the collective water supply system. During monitoring, the physical, chemical, and biological stability of water was assessed, which is the main determinant ensuring the appropriate quality of water for consumers. The physicochemical and microbiological quality of water was analyzed for two distribution systems (DSs), including the analysis of heavy metals (Zn, Fe, Mn, Cr, Ni, Cu, Cd, Pb). The tests carried out showed that in both distribution systems, the water supplied to consumers met the guidelines for water intended for human consumption. It can be considered that the risk of uncontrolled changes in water quality in DSs with an average water production of &lt;10,000 m3/d and the length of water pipelines &lt; 150 km is very low. The water introduced into the system differed in the place of water intake and water purification technology, which influenced the final water quality. In DS(II), higher values were recorded for hardness, conductivity, calcium, alkalinity, nitrates, and DOC. It was found that the content of heavy metals during water transport to the consumer increased in the case of DS(I) for Zn, Ni, Cu, Cd, and Pb, and in the case of DS(II) for Fe, Mn, Ni, Cu, Cd, and Pb. The observed differences resulted from the different quality of the intake water as well as from different materials used to build internal installations and their age and technical condition. The analyzed tap water was characterized by physical and chemical stability. However, the water did not meet the guidelines for water biostability due to the increased content of biogenic substances.

Unlocking the potential of lignocellulosic waste: A kinetic modeling approach for bio-coagulants in sewage water treatment

This study explores the potential of lignocellulosic materials, specifically sugarcane bagasse (SB) and coconut fibers (CNW), as coagulants and flocculants for sewage water treatment in combination with alum. The main aim is to evaluate the efficacy of alum:SB and alum:CNW combinations in improving water quality parameters, such as turbidity, EC, pH, TSS, TDS, DO, BOD, and COD, using modified methods (primary and secondary treatment). The results of the water quality parameters show significant reductions in turbidity of 95.32% and 90.94% for sewage waters treated with alum:SB and alum:CNW, respectively, as well as notable reductions in TDS (70.58%, 60.78%), TSS (98.63%, 97.27%), BOD (76.51%, 51.13%), and COD (95.07%, 76.47%). Moreover, bio-coagulants such as alum, SB, CNW, alum:SB, and alum:CNW were characterized by FT-IR. In comparison to other coagulants, the alum:SB treated sewage water was found to be efficient and have excellent coagulation activity (90%). The turbidity removal by both lignomaterials conformed to the WHO and BIS acceptable limits for finished water quality. Therefore, the highest turbidity reduction was achieved in alum:SB>alum:CNW treated sewage water. Statistical analysis also confirmed the effectiveness of alum:SB, highlighting its potential as a feasible option for sewage water treatment through factor and correlation analysis. The MANOVA (p < 0.05) result indicates that both bio-coagulants were significantly different. This study emphasizes the potential and eco-friendly method of using lignocellulosic bio-coagulants for the treatment of municipal sewage water.

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

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

Modeling and experimental evaluation of membrane distillation aimed at urine treatment for direct potable reuse in space stations

Improving wastewater reuse systems represents a game changer for the economy of space exploration activities. The goal of this research is to evaluate direct contact membrane distillation for the treatment of urine aimed at direct potable reuse in space stations. A transient, 2-D model able to predict the membrane distillation system behavior under different operating conditions is developed. The model is validated by experimental tests conducted with a synthetic urine-like feed solution, considering both productivity and final water quality. The water flux and quality analyses imply high rejection of soluble salts and organics. However, direct water reuse may be compromised by the ammonia passage. A sensitivity analysis is thus performed to investigate the effects of feed pH, temperature, and cross-flow velocity on water flux and ammonia passage. The system shows the capability of treating 8 L of urine up to 90–95 % recovery rate, during 10 h of daily operation at 40 °C feed and 20 °C distillate inlet temperatures. This amount is sufficient to satisfy four crew members while meeting high system compactness. Concurrently, the ammonia passage may be limited by lowering the feed pH, thus easing the post-treatment steps necessary for safe direct reuse.

Pilot study of emerging low-energy seawater reverse osmosis desalination technologies for high-salinity, high-temperature, and high-turbidity seawater

The increasing impact of climate change has worsened drought conditions, leading to a surge in the demand for seawater desalination. However, current seawater reverse osmosis (SWRO) desalination technologies are not energy-efficient for handling the high-salinity, high-temperature, and high-turbidity seawater found in the Arabian Gulf. Therefore, a pilot-scale SWRO desalination plant was established to evaluate the new desalination technologies. The pilot plant tested high-performance SWRO membranes, meshed tube filtration (MTF) as a low-energy pretreatment for the high turbidity induced by algal blooms, and membrane capacitive deionization (MCDI) to improve permeate quality. The high-performance SWRO membrane demonstrated exceptional salt rejection and produced permeate quality in the range of 250–455 mg/L from the feed with salinities of 47,500–53,500 mg/L. MTF was effective in controlling turbidity, and the energy consumption was reduced by 77 % compared to the existing pretreatment process. Furthermore, MCDI exhibited similar levels of energy efficiency as brackish water reverse osmosis and may have the potential for future deployment by enhancing process development. Based on the pilot plant results, it is expected that a 100,000–200,000 m3/d SWRO desalination plant will have a specific energy consumption of 3.11–3.13 kWh/m3 for final product water quality at or below 200 mg/L.

Recirculating Water through Concrete Aggregates Rapidly Produced Ecologically Hazardous Water Quality

The use of recycled concrete aggregates as a construction material is growing and this study was conducted to investigate the potential water quality issues that arise when concrete aggregates are exposed to water. The water used in the study was from a high-conservation-value wetland. It was dilute (17.8 µS cm−1), acidic (pH 5.97) and poorly buffered. The ionic composition comprised sodium, bicarbonate and chloride ions. Water was recirculated for 60 min through a control treatment and three treatments containing recycled concrete aggregates (RCAs) of different fragment sizes (10 mm, 20 mm and 60 mm). The fragment size influenced the final water quality, but the response patterns varied between the attributes tested. Post-recirculation, the RCA treatments increased the electrical conductivity by 6 to 12 times; pH by 2.3 to 3.8 pH units; and concentrations of calcium, potassium, bicarbonate and sulphate. The water exposed to RCA materials also increased the concentrations of several metals (aluminium, arsenic, copper, lead and zinc), resulting in hazardous concentrations for aquatic species according to ecological water quality guidelines. Strontium concentrations in water exposed to RCAs increased by 30 to 120 times background levels. The results from this study added further support to a growing body of evidence that the exposure of concrete materials to water can produce environmentally hazardous water quality.

Practical Framework for Evaluation and Improvement of Drinking Water Treatment Robustness in Preparation for Extreme-Weather-Related Adverse Water Quality Events.

Robustness is the ability of a drinking water treatment plant (DWTP) to achieve the desired finished water quality even during adverse raw water quality events. Increasing the robustness of a DWTP is beneficial for regular operations and especially for extreme weather adaptation. This paper proposes three robustness frameworks: (a) a general framework outlining the main steps and methodology for systematic assessment and improvement of the robustness of a DWTP, (b) a parameter-specific framework applying the general framework to a water quality parameter (WQP), and (c) a plant-specific framework applying the parameter-specific framework to a DWTP. A parameter-specific framework for turbidity is presented using the turbidity robustness index (TRI) for evaluation and applied to a full-scale DWTP in Ontario, Canada. This evaluation was conducted with historical plant data, as well as bench-scale experimental data simulating extremely high-turbidity scenarios. The framework application is capable of identifying (i) less robust processes which are likely to be vulnerable during climate extremes, (ii) operational responses to increasing short-term robustness, and (iii) a critical WQP threshold beyond which capital improvements are necessary. The proposed framework provides insights into the current state of robustness of a DWTP and serves as a tool for climate adaptation planning.

Understanding point-of-use tap water quality: From instrument measurement to intelligent analysis using sample filtration

In most cases, point-of-use tap water quality is not routinely monitored due to widely-dispersed sampling sites and the costly tests. Although previous studies have revealed the variation of drinking water quality during distribution in municipal networks, the influence of aging pipes in buildings on quality is still unknown and this makes it difficult for water utilities to conduct regular maintenance. Herein, we have undertaken a survey of tap water samples across 8 districts in Beijing (China) to evaluate the potential effects of pipe age on point-of-use water quality, including turbidity, organic matter characteristics, and bacterial community. By grouping the collected samples according to the pipe age and source water respectively, the results suggested that bacterial diversity is significantly influenced by the pipe age. However, bacterial community structure is clearly influenced by the source water. Similarly, aging pipes in buildings are also responsible for the deterioration of the final water quality, and their effects have been closely linked to selected water quality parameters by evaluating the relevant factors. Moreover, the interrelationships between physico-chemical parameters and bacteria abundance were identified. For example, pH, Ca2+, Mg2+, Na+ and K+ showed a positive relationship with Bacillus abundance. In addition, an intelligent analysis method for understanding pipe age, organic matter concentration, and hardness (i.e., Ca2+ and Mg2+ concentration), based on image analysis of filtered membranes has been developed. The accuracy of prediction was encouraging, but can be improved with the collection of more data from tap water samples. We expect that this method can be exploited by the public to monitor their tap water and provide a feasible and cost-effective approach for water suppliers to locate aging/deteriorating pipes which need to be replaced or maintained.

Modification of Disinfection Process at a Local Water Treatment Plant—Skawina (Poland)

This paper summarizes studies undertaken at a water treatment plant in Skawina (WTP Skawina) where the disinfection process was modified by introducing a mobile ozonation system. The application of a small-size, fully-automated ozonation installation only slightly complicates the water treatment process, without the need to redesign the water treatment line, and with relatively low investment costs. The aim of this study was to analyze whether the change of the disinfection method affects the final water quality. The investigated water samples were treated in the mobile ozonation system using a disinfection process with only sodium hypochlorite. Treated water was of excellent quality, and seasonal variations in raw water parameters (variable organic matter contents) did not result in elevated trihalomethanes (THM) and bromate concentrations. Despite the trace amounts of bromides in the water prior to treatment, the water in the municipal drinking water system did not contain determinable amounts of bromates. The bromine concentrations in the treated water supplied to the water distribution system were higher than in raw water, which could be attributable to the presence of bromine as a contaminant in sodium hypochlorite (the disinfection agent). Water quality tests carried out by the water treatment plant (WTP) and by the State Sanitary Inspectorate after the modification of the process line confirmed the high quality of water in the distribution network after the change of disinfection method.

Improvement of wastewater quality of Dhaleswari river, Bangladesh using submerged macrophyte Egeria densa

Clean water is one of the significant goals among the 17 Sustainable Development Goals (SDGs), which will be achieved by at least 2030. It includes six outcome-oriented targets- improve water quality, wastewater treatment, ensure freshwater supplies are three of them. In Bangladesh, Freshwater ecosystem is continuously degraded due to rapid industrialization, which occurred along the riverside areas. In this context, laboratory-based work has been conducted to analyze the water quality of Dhaleshwari River, Bangladesh, which has already been polluted by industrial waste. The collected water samples were treated by submerged macrophyte Egeria densa to observe the changing water quality parameters. The growth of plants and roots were assessed after 10 days of exposure to three categories of water treatment. Initial and final water quality parameters were observed by the analysis of pH, EC, TDS, TSS, Acidity, Alkalinity, Total Hardness, Ca Hardness, COD, Sulphate (SO42-), Phosphate (PO43) Total Chlorine (Cl-) and Copper (Cu2+). The result showed that almost all the toxic parameters of water were reduced significantly at the end of the experiment. The present study hypothesized that submerged macrophyte E. densa can be used as a potential tool to upgrade the water quality of polluted rivers.Keyword: Clean water, Submerged macrophyte, SDG 6, Dhaleswari River, Freshwater ecosystem

Quality difference between sachet and bottled water produced under the same conditions

The study investigated the physicochemical and microbial qualities of freshly produced packaged water in Nsukka, Nigeria in a way that reveals the effect of the filling and sealing processes on the final water quality. The result shows that the physicochemical parameters were largely within standards, except for a few packaged water that violated the standards for pH (7%), iron (Fe) (39%), and conductivity (32%). More than 70% and 3% of the packaged water tested positive for total coliform and E. coli respectively, which suggest inadequate disinfection and recent faecal contamination. The uniformity of the physicochemical parameters among sachet and bottled water collected from the same brand suggests that the filling and sealing processes either have similar or no effect on the physicochemical properties. Microbial parameters of packaged water from the same brand were less uniform but still within the same confident limits. Better surveillance and stricter supervision by the regulatory authorities, including insistence on full compliance with the general hygiene provisions, are required to put an end to the proliferation of unsafe packaged water and the associated life-threatening illnesses.

Water Quality Classification for Inland Lakes and Ponds with Few Color Image Samples Based on Triple-GAN and CSNN

Water color is an important representation reflecting the characteristics of its quality in inland lakes or ponds; however, sufficient water color image samples are often difficult to obtain due to the limitation of fishery production. For few color image samples, the existing data enhancement methods based on the depth generation model have the problems of low quality of generated data, difficulty of network training, and so on; moreover, for image classification, traditional methods based on convolutional neural network (CNN) cannot effectively extract the potential manifold structure features in the image and the full connection layer in CNN cannot simulate biological neurons well, resulting in high time cost and low efficiency. In this paper, a water quality classification method has been proposed to solve the above problems, the improved semisupervised triple-generation adversarial network (triple-GAN) algorithm is used to enhance the few water color image samples, and the feature data can then be extracted from enhanced data by manifold learning method t-distributed stochastic neighborhood embedding (t-SNE). Moreover, convolutional spiking neural network (CSNN), in which spiking neural network (SNN) has replaced the original full connection layer of CNN, is used for final water quality classification. The main contribution of this paper is to build a new algorithm framework, introduce triple-GAN and CSNN into the field of classification of few water color image samples for the first time, and make an exploration of integrating artificial intelligence (AI) and water quality analysis problems. By comparing with traditional methods, the proposed method is proved to have the advantages of less time-consuming, low operation cost, and high classification accuracy.

Organic matter removal and antifouling performance of sulfonated polyaniline nanofiltration (S-PANI NF) membranes

Natural organic matter (NOM) removal from water prior to other treatment processes can improve treatment efficiency and final water quality. Here, NOM removal across five size fractions by newly developed sulfonated polyaniline nanofiltration (S-PANI NF) membranes was compared with a commercial membrane and conventional adsorption-coagulation-flocculation, optimized for NOM removal. Artificially prepared surface water and seawater containing 10 – 100 mg C L−1 NOM extract and a stabilized landfill leachate served as test solutions. S-PANI NF membranes showed best NOM separation performance for both surface and seawater followed by the commercial membrane and conventional treatment. For landfill leachate conventional treatment had the best performance followed by S-PANI NF membranes. S-PANI performed slightly better in removal of chemical oxygen demand (COD) (74%) compared to the commercial membrane (70%) and conventional treatment (70%). Both membranes performed consistent with increasing salinity and NOM concentration, while experiencing a modest carryover at higher salinity. During long-term fouling S-PANI exhibited slower growth in transmembrane pressure (TMP), less affinity towards organic matter and higher flux recovery compared to the commercial membrane, particularly at high NOM concentration. This is the first study to investigate S-PANI membranes for water treatment applications and under high-fouling conditions. Results indicate S-PANI NF membranes are promising for such applications. In addition, this study also provides an inter-process comparison for NOM removal over an extreme range of water matrix conditions.

Induksi hormon oodev untuk meningkatkan tingkat kematangan gonad ikan cupang betina (Betta splendens) melalui pakan

Betta fish are freshwater ornamental fish that are very popular and have quite high economic value, but the reproductive process still depends on the spawning season, so an increase in reproductive potential is needed. The experiment was conducted in order to determine the role of each induction Oocite development (Oodev) hormone in the diet to betta fish female final maturation process and morphology gonads. Completely randomized design (CRD) with one factor consisting of 5 treatments and 3 replications. The main factors are Oodev hormone dosage: 0.0 mL.kg-1 fish weigh; 0.5 mL.kg-1 fish; 1.0 mL.kg-1 fish; 1.5 mL.kg-1 fish and 2.0 mL.kg-1 fish. We used 135 female broodstock with initial weight range ± 1-2.15 g tail-1 and at stage II of gonad maturation. Fish were fed three a day at 07.00 am, 12.00 am and 05.00 pm at satiation level during 45 days. During the final maturation, gonad morphology, survival rates and water quality were observed. The results show that Oodev hormone induction could improve final maturation up to 266.66%. This result comparatively higher than 0.0 mL.kg-1 and 0.5 mL.kg-1 fish hormone induction, and produce 100% of mature broodstock. Thus, the Oodev hormone induction at optimal dose of 1.16 mL.kg-1 of fish can improve the induction maturation up to 2-3 times faster maturation frequency on the out of spawning season.Keywords: Female Betta splendens; Feed; Final maturation; Oodev

Induction of Oodev Hormone to increase Gonad Maturity Rate Female Betta Fish (Betta splendens) Through Feed

Betta fish are freshwater ornamental fish that are very popular and have quite high economic value, but the reproductive process still depends on the spawning season, so an increase in reproductive potential is needed. The experiment was conducted in order to determine the role of each induction Oocite development (Oodev) hormone in the diet to betta fish female final maturation process and morphology gonads. Completely randomized design (CRD) with one factor consisting of 5 treatments and 3 replications.The main factors are Oodev hormone dosage: 0.0 mL.kg-1 fish weigh; 0.5 mL.kg-1 fish; 1.0 mL.kg-1 fish; 1.5 mL.kg-1 fish and 2.0 mL.kg-1 fish. We used 135 female broodstock with an initial weight range ± 1-2.15 g.ekor-1 and at stage II of gonad maturation. Fish were fed three a day at 07.00 am, 12.00 am, and 05.00 pm at satiation level during 45 days. During the final maturation, gonad morphology, survival rates, and water quality were observed. The results show that Oodev hormone induction could improve final maturation up to 266.66%. This result is comparatively higher than 0.0 mL.kg-1 and 0.5 mL.kg-1 fish hormone induction and produces 100% of mature broodstock. Thus, the Oodev hormone induction at optimal dose of 1.16 mL.kg-1 of fish can improve the induction maturation up to 2-3 times faster maturation frequency on the out of spawning seasonKeywords:Female Betta splendens; final maturation; Oodev; feed

Final rinse water quality for flexible endoscopy to minimize the risk of post-endoscopic infection. Report from Healthcare Infection Society Working Party

Endoscopic procedures in diagnostic and surgical settings are performed routinely and the number of patients undergoing these procedures is progressively increasing. Outbreaks and sporadic cases of infection associated with the use of endoscopes have decreased due to improvements in endoscope decontamination. The majority of infections occur due to the failure in endoscope reprocessing; however, microbial contamination of the final rinse water has been implicated in some outbreaks and pseudo-outbreaks.