Substances In Water Bodies Research Articles

Formation of halonitromethanes from different nitrophenol compounds during UV/post-chlorination: Impact factors, DFT calculation, reaction mechanisms, and toxicity

As ubiquitous chemical substances in water bodies, nitrophenol compounds (NCs) can form chlorinated halonitromethanes (Cl-HNMs) in the chlorination process. This work chose six typical NCs to explore Cl-HNMs produced during the UV/post-chlorination process, and Cl-HNMs yields from these NCs followed the increasing order of 4-, 2-, 2-amino-3-, 2-methyl-3-, 3-, and 2-chloro-3-nitrophenol. The Cl-HNMs yields increased continually or increased firstly and declined with post-chlorination time. Increasing chlorine dosage favored Cl-HNMs formation, while excessive chlorine dosage decreased Cl-HNMs produced from 2- and 4-nitrophenol. Besides, appropriate UV radiation, acidic pH, and higher precursor concentrations facilitated Cl-HNMs formation. Then, the reaction mechanisms of Cl-HNMs generated from these different NCs were explored according to density functional theory calculation and identified transformation products (TPs), and the main reactions included chlorine substitution, benzoquinone compound formation, ring opening, and bond cleavage. Moreover, the Cl-HNMs generated from 2-chloro-3-nitrophenol were of the highest toxicity, and the six NCs and their TPs also presented ecotoxicity. Finally, two kinds of real waters were used to explore Cl-HNMs formation and toxicity, and they were significantly distinguishable compared to the phenomena observed in simulated waters. This work will give new insights into Cl-HNMs formation from different NCs in water disinfection processes and help better apply the UV/post-chlorination process to water treatments.

Synergistic interactions between the emerging contaminant ivermectin and the ubiquitous pesticide glyphosate at an environmentally relevant ratio on Rhinella arenarum larvae

Glyphosate (GLY) is a widely used broad-spectrum herbicide, and ivermectin (IVM) is a commonly used antiparasitic in livestock farming. Both substances can be found in water bodies from agricultural areas and can have negative impacts on ecosystems. The aim of this study was to evaluate the lethal and sublethal toxicity individually and in combination of a glyphosate-based herbicide (GBH) and an ivermectin commercial formulation (ICF). Groups of 10 larvae were exposed for 504 h, in triplicate to a concentration gradient of the commercial formulation of glyphosate and ivermectin, individually, and to a series of dilutions of a non-equitoxic mixture of both compounds based on environmental concentrations. Additionally, biomarkers of oxidative stress (catalase, glutathione S-transferase, and reduced glutathione) and neurotoxicity (acetylcholinesterase and butyrylcholinesterase) were evaluated at sublethal and environmental concentrations of ivermectin (0.00125 mg/L) and glyphosate (0.7 mg/L) individually and in mixture. The ICF (LC50-504h: 0.047 mg ai IVM/L) was more toxic to larvae than the GBH (LC50-504h: 24.73 mg ae GLY/L). In terms of lethality, exposure to the mixture was synergistic at all exposure times. Both compounds separately caused alterations in the biomarkers of oxidative stress and neurotoxicity. Regarding sublethal effects in organisms exposed to the mixture, potentiation was observed in acetylcholinesterase. The simultaneous exposure to both substances in water bodies can have synergistic and negative effects on aquatic organisms.

Study on Removal of Endocrine Disruptors in Water Bodies by Advanced Persulfate Oxidation Technology: A Review

Endocrine disruptors (EDCs), as emerging micro-contaminants, interfere with hormones secretion and are harmful to human reproductive system when entering human body. Derived from industry pollution, municipal sewage or agricultural irrigation and run-off, they are able to penetrate to groundwater or gather into surface water that finally supply humans daily use. Water quality is closely related to human health, especially drinking water, so it is necessary to remove EDCs from polluted water bodies before water is treated and put into use. It is how to efficiently and maximally remove such substances in water bodies that has been a hot issue recently, which has stirred wide attention both at home and abroad. This paper reviews the previous research achievements in this field, simply expounds the mechanism of the reaction between persulfate and EDCs, discusses the characteristics and drawbacks of different activation methods, and finally gives suggestions on how advanced persulfate oxidation technology will develop to an optimization in the future when considering low cost, high removal efficiency and zero secondary pollution.

Bio remedial Process: A Review on Removal of Fluoride from the Waste Water

Ground water has always been an important and most dependable source of water since prehistoric ages, but with rapid industrialization to meet the needs of growing population has stressed the ground water reservoir. Stress to ground water reservoir is just one problem; industrial waste has also introduced lots of new chemical substances in water bodies. Fluorides are one such pollutant that undermines living life forms especially human beings .There are primarily two sources of fluoride contamination in ground water. Geogenic sources and anthropogenic sources. Talking about the status of fluoride contamination it can be seen in more than 25 countries worldwide. In India itself 19 states and at least 132 districts have witnessed the problem of water contamination, Fluoride contamination is also impacting the health of people adversely. Diseases like skeletal fluorosis, non –skeletal fluorosis, and dental fluorosis are the most common health problem from fluoride contamination .Due to fluoride contamination diseases in plants like Chlorosis, Necrosis is impacting plant body. Thus, to remove fluorine contamination from water we can use bioremediation process. Bioremediation strategies can be classified mainly in two categories in – situ techniques and ex –situ techniques. Its mode of action primarily includes use of microbes in processing the fluoride contamination. This shows that bioremediation has lots of advantages like it’s a natural process, cost effective etc. But it too have some disadvantages like they are highly specific and it takes longer time etc. Considering all the merits and demerits of bioremediation, it is the most effective technological tool that holds great value for the future as scientists learn more about its capabilities and the curiosity to find more appropriate methods are still going on. This review article deals with ground water pollution due to fluoride concentration. We have thoroughly reviewed on its impact on health of plants and animals and the bioremediation processes to cure the water contamination

PHARMACEUTICAL WASTE – A NEW THREAT TO LAKE ECOSYSTEMS

According to the Basel Convention (1998), pharmaceutical waste is waste from medical care in hospitals, medical centers and clinics, waste from the production and preparation of pharmaceutical products, waste pharmaceuticals, drugs and medicines, wastes from the production, formulation and use of biocides and phytopharmaceuticals. They belong to the so-called Yellow List, and are all, without exception, regarded hazardous. A review of the results of studies on pharmaceutical wastes in water bodies (rivers and lakes) in Russia and abroad has been produced. Medicines are an integral part of medical practice. They serve the preservation of the health of the population and, as a result, enhance the quality and prolong the duration of life. On the other hand, pharmaceutical industry waste is increasingly affecting wildlife, as unused medicines are often discarded or disposed of improperly. At the beginning of the 21st century, the European Environment Agency (EEA) designated the impact of active pharmaceutical ingredients on the environment as a new environmental problem. The main pathways by which drugs reach the environment have been charted. Meanwhile, Russia has no system to regulate maximum permissible concentrations of drugs in water bodies. The purpose of this study is to work out a methodology for calculating maximum permissible concentrations of drugs in water bodies of fishery importance. An adequate correlation has been established between maximum permissible concentrations of harmful substances in water bodies of fishery importance (MPCf) and their average lethal concentrations for daphnia. Indicative MPCf values have been calculated for 12 pharmaceutical products.

Multifunctional porous β-cyclodextrin polymer for water purification

Keeping water clean is of vital significance for human health and environmental protection. In order to remove organic micro-pollutants and natural organic substances in water bodies and kill pathogenic microorganisms simultaneously, this study synthesized a multifunctional porous β-cyclodextrin polymer with a high specific surface area by introducing quaternary ammonium groups and rigid benzene rings, respectively, which was then polymerized with crosslinking agent-4,4′-bis (chloromethyl)-1,1′-biphenyl (BCMBP) in an ionic liquid system. The grafting of quaternary ammonium groups was beneficial for the removal of negative-charged humic acid (HA) and sterilization. The introduction of numerous rigid structures during benzylation and Friedel-Crafts alkylation reaction could significantly improve the porosity and specific surface area of the polymer, conducive to the exposure of cyclodextrin binding sites and contaminant adsorption. By changing the proportions of quaternization and benzylation, the structure and surface properties of the polymer could be adjusted, thus further regulating the adsorption performance. Compared with activated carbon, the polymer named BQCD-BP with a huge surface area of 1133 m2 g−1 prepared under optimized conditions showed outstanding adsorption performance and sterilization ability. The pseudo-second-order kinetic constant of BQCD-BP reached 1.2058 g·mg−1·min−1, which was approximately 50 times greater than that of activated carbon (0.0256 g·mg−1·min−1) under the same experimental condition. The adsorption capacity of BQCD-BP to HA was twice as high as that to AC, and the antibacterial ability of BQCD-BP was significant, achieving 90% at the dosage of 1g L−1. Moreover, the adsorption process was hardly affected by the hydrochemical conditions, and the polymer was easy to regenerate. In addition, the excellent adsorption and antibacterial performance of the polymer were also identified by natural water treatment. COD was almost completely removed, and the removal efficiency of TP reached 92% after contact with BQCD-BP. The sterilization rate of BQCD-BP to viable bacteria in complex water bodies reached 82%. Undoubtedly, BQCD-BP is a potential multifunctional water treatment material with reasonable design in the actual water purification.

Research on the Application of Multimodal-Based Machine Learning Algorithms to Water Quality Classification

With the development of society and the accelerated industrialization, the problem of water pollution has become increasingly prominent. In order to stop the gathering and diffusion of harmful substances in water bodies, leading to further deterioration of water quality and more serious environmental problems, environmental management departments have developed a series of pollutant discharge standards to prevent water pollution in real time. Common testing methods are the colorimetric method and TDS (total dissolved solids) value testing method, which are mostly through water bodies that contain acid, alkali, salt, and other indicators of the concentration test, to produce an assessment of water quality. However, the traditional methods of water quality testing, whether in the measurement time or in the accuracy of the test, are certain defects. In order to be able to quickly detect the concentration of water quality indicators in water bodies, timely response and treatment of highly polluted water bodies are urgently needed. In this paper, we propose a water quality detection classification model based on multimodal machine learning algorithm. Firstly, we preprocessed and analyzed the collected water quality dataset and determined the reasonable and perfect water quality classification influencing factors. Then, we successively built 15 kinds of classification models based on machine learning algorithms for water quality detection. At the same time, we evaluated the performance of each model. From the four evaluation indexes of precision, recall rate, F1 value, and accuracy, respectively, the real value is compared with the predicted value of each model. The experimental results show that sulfate, pH, solids, and hardness are the important influencing factors to perform water quality testing. And the three models XGBoost (Extreme Gradient Boosting), CatBoost (Categorical Boosting), and LGBM (Light Gradient Boosting Machine) have better performances in conducting water quality testing. Finally, we further optimized the classification models based on XGBoost, CatBoost, and LGBM by using two major tools: cross-validation and hyperparameter tuning.

Biotechnological principles for improving the ecological state of natural springs in the city of Lviv

A large number of water sources were found on the territory of Ukraine. Water sometimes has healing properties, but spring water's quality and “purity” cannot be guaranteed. It depends not only on people's daily activities but also on the location of the source. On the territory of the city of Lviv, there are several springs, the water used by the city's residents. An important problem is the removal of nitrites, nitrates, and sulfates that enter the water due to metabolic processes and disinfection using chlorammonization. The article examines the current ecological, microbiological and bacteriological state of natural sources in Lviv and characterizes water bodies' physical and chemical indicators. An analysis of literary data on the main characteristics of spring waters and their purification methods was carried out. The necessity, and therefore the relevance, of the analysis and detailed assessment of the water quality of springs in the territory of Lviv, is shown, namely: spring No. 1 in the park “Zalizna Voda” (Lviv, Ternopilska St.); spring No. 2 in the park “Zalizna Voda” (Lviv, Myshugy Street); spring No. 3 in Stryi Park (Lviv, Stryiska St.). Based on the obtained results, biotechnological methods and possible ways of solving the issues of ecologically safe use of spring waters of the city of Lviv are proposed. The results of the analysis were compared with the MPC (limit-permissible concentrations) of harmful substances in water bodies following Order No. 400 dated 12.05.2010 on the approval of the State sanitary standards and rules “Hygienic requirements for drinking water intended for human consumption” (DSanPiN 2.2. 4-171-10). Some problems were identified, which are solved by involving associations of microorganisms. Increased exploitation of biological processes for drinking water purification is the best way to ensure safe water in the city. According to the research results, it was determined that effective methods of water purification could be achieved when applying the proposed biotechnological methods.

Assessment of the quality of pond waters of Lviv region and prospects for the use of phytoplankton biomass in these reservoirs

Reservoirs and ponds belong to specific objects of water resources. Most reservoirs and ponds are of anthropogenic origin. They are of special importance for the Lviv region due to its terrestrial properties. In modern conditions, the importance of reservoirs and ponds is growing significantly. This is due to the fact that in many areas they form nuclei around which recreational complexes are formed. Reservoirs and ponds play an important role in the health and recreation of people. They are created by man to regulate runoff for commercial use of surface waters. The use of artificial reservoirs – reservoirs and ponds is carried out mainly depending on the water content and economic specialization of the regions. Therefore, it is very important to determine the quality of water in the ponds of Lviv region to establish ways of its further use. Recently, the problem of water enrichment with nutrients due to anthropogenic activity, which contributes to the growth of bioproducts of algae and other mass forms of aquatic organisms, has become especially acute. The article considers the rates of Lviv district of Krotoshyn village (№ 1, № 2) and Zhyrivka village (№ 3). The aim of the work was to determine the qualitative assessment of pond waters of Lviv region and the study of phytoplankton biomass and to determine the prospects for its use. The experimental part of the research was performed in the production laboratory at vul. Stryjska, 18a. The material for the research was water samples. The results of the analysis were compared with the list of maximum permissible concentrations (MPC) of harmful substances in water bodies in accordance with Order № 400 of 12.05.2010 on approval of State Sanitary Norms and Rules “Hygienic requirements for drinking water intended for human consumption” DSanPiN 2.2. 4-171-10). According to research, the water in the pond in the village of Zhyrivka turned out to be very dirty. Dirty water was in pond № 2 in the village of Krotoshin and polluted in the same village in pond № 1. The water in the ponds in the village of Krotoshin was pure in color. The water in the pond in the village of Zhyrivka was polluted, green and yellow. The highest pH level with a value of 8.8 was in the water pond in the village of Zhirivka, although it should be noted that this figure was quite high in the other two studied ponds. The lowest concentration of oxygen was in the pond in the village of Zhyrivka, the phosphate content was normal only in the water of the pond № 1 in the village of Krotoshyn. The largest amount of phytoplankton biomass was found in the village of Zhyrivka (pond № 3), which indicates pollution and “blooming” of the reservoir. This biomass can be used directly as an effective organo-mineral fertilizer.

Isolation and Identification of an Efficient Aerobic Denitrifying Pseudomonas stutzeri Strain and Characterization of Its Nitrite Degradation

Nitrogen pollution in water bodies is becoming increasingly serious, and how to remove nitrogen from water bodies economically and effectively has become a research hotspot. Especially in recent years, with the gradual expansion of aquaculture in China, the content of nitrite and other nitrogen-containing substances in water bodies has been increasing, which inhibits the growth of farm animals and is one of the causes of eutrophication in water bodies. In this study, a strain of bacteria was isolated from the sludge of an aquaculture fishpond and identified as Pseudomonas stutzeri, which can efficiently degrade nitrite. After continuous domestication in nitrite mixed solution, the nitrite nitrogen reduction capacity of P. stutzeri was significantly improved. Univariate experiments aiming to optimize the degradation conditions indicate that the optimal culture conditions for strain F2 are: medium with a carbon source of sodium succinate; C/N of 18; pH of 8; culture temperature of 28 °C; and shaking speed of 210 rpm in the shaker. Under the optimal culture conditions, the NO2−-N concentration of the culture solution was 300 mg/L, and the nitrite removal rate reached 98.67%. Meanwhile, the results of the nitrogen balance test showed that the strain converted 6.1% of the initial nitrogen into cellular organic nitrogen and 62.3% into gaseous nitrogen.

Assessment of microbiological indicators and monitoring of a sociological survey of the quality of sources in the city of Lviv

There are a number of springs on the territory of Lviv, water from which is used by the city residents. It should be noted that natural resources cannot be systematically used by the population for drinking purposes, as they are not sources of centralized water supply and, accordingly, do not have service personnel. No sanitary protection zones have been established for such sources, within which economic activities are prohibited. In this regard, the quality of water from such natural sources has unstable indicators, which depend on many factors of man-made and natural factors (sanitary-chemical and sanitary-microbiological indicators can sometimes fluctuate within one week), which makes it unfit for human consumption and can lead to acute intestinal infections of bacterial and viral etiology, a number of infectious diseases. The article considers the current ecological, microbiological state of natural sources of the city of Lviv. The necessity, and hence the relevance of the analysis and detailed microbiological assessment of water quality of springs in the city of Lviv, namely: springs № 1 in the park "Zalizna Voda" (Lviv, Ternopilska Street); springs № 2 in the park "Zalizna Voda" (Lviv, Myshuhy Street); springs № 3 in Stryiskyi Park (Lviv, Stryiska Street). A sociological survey of city residents on the use and consumption of water from the studied sources was conducted. The results of the analysis were compared with the list of maximum concentration limits of harmful substances in water bodies in accordance with the order № 400 from 12.05.2010 on approval of State sanitary norms and rules “Hygienic requirements for drinking water intended for human consumption” (DSanPiN 2.2.4-171-10).

Complexing ability of organic compounds and their influence on the human body (review)

Introduction. Increased content of organic substances in natural waters, expanding the list of input substances to water bodies, owing to industrial and economic activities of a person, and climate changes is an urgent issue. Against this background, compounds with unknown chemical and toxic properties are likely to appear. The purpose of this study is to collect data concerning the ways for organic compounds entering water bodies and the human body, study data on interaction mechanisms of organic substances with metals, reveal the fate of known organic chelators, complexing agents as well as organometallic compound shaped by them inside the body. The literature search was carried out in Scopus, Web of Science, CyberLeninka databases. Sources of organic substances entering water bodies, properties of organic substances. There are three types of organic substances in water bodies, divided by the sources of their occurrence (inflow): terrigenous origin, shaped inside water bodies and coming from man-made sources. Organic compounds may produce soluble and insoluble compounds with metals and colloids. Mechanisms of interaction of organic substances with metals. Bonding of organic substances takes place by the type of chelation and complexation. There are factors for bonding: functional group content, the molecular mass of substances, ion radius, and competitive interaction with binding sites. Substances having binding properties include phenolic compounds, carboxylic acids, polysaccharides, and flavonoids. Considering that phenolic compounds are located in large quantities in plant and animal tissues, this group of compounds has been researched more thoroughly in terms of interactions with metals and toxicometry. Intake of organic and organometallic compounds into the body, their kinetics, metabolism and decay. Organic compounds, chelates, and complexes enter the body with drinking water, food, and drugs. They are also generated in the body, including by replacing ions. Data on biochemical and toxicological studies of currently known compounds is given

The spatiotemporal migration process of Cd content and the theory developed

According to the survey data of Jiaozhou Bay water body from 1984 to 1988, this paper analyzed and explored the data of Cd content each year, and studied the sources, water quality, distribution and migration conditions of Cd content in the waters of Jiaozhou Bay from the perspectives of volume, horizontal distribution, vertical distribution, seasonal distribution, regional distribution, structural distribution and tendency distribution. On the time scale, there are five migration processes of Cd content in the waters of Jiaozhou Bay. The author proposed five material migration theories to present the dynamic migration process of material in the water body. These rules, processes and theories not only provide solid theoretical bases for the migration of Cd content in the waters, but also provide enlightenment for the study of the migration of other substances in water bodies.

Impact of Pesticide Toxicity in Aquatic Environment

The intensified agricultural crop production for growing high yield varieties requires the indiscriminate use of pesticides and fertilizers, which protect the crop from pests, thus helps in improving the quality and quantity of crops. The aquatic environment gets contaminated by the application of pesticides through several routes: runoff, spray drift, and leaching, which pose serious health risks to the aquatic ecosystem as well as to human beings. This exposure can directly affect all levels of biological organization, including primary producers, microorganisms, invertebrates, or fish. Thus, monitoring methods should be adopted for controlling the runoff events in the spraying method, such as suspended matter sampler for particle-associated pesticides that can be used for controlling the number of toxic substances in water bodies.

Environmental Risk assessment of Chlorpyrifos and TCP in Aquatic Ecosystems

Chlorpyrifos is a commonly used pesticide that belong to the organophosphorus pesticides (OPPs) group. Chlorpyrifos is widely used in residential environments and agriculture for pest control. As many OPPs, Chlorpyrifos degrades faster to more complex and toxic compounds under natural conditions, thus diverse effects of these compounds over aquatic species are unknown. Due to the risk that pesticides as Chlorpyrifos, which mainly breaks down to 3,5,6- trichloro-2-pyridinol (TCP) on the ecosystems, there is an increasing need to intensify the environmental monitoring and ecotoxicological risk assessment for both substances. Risk assessment provides a systematic approach for characterizing the nature and magnitude of the risks associated with environmental health hazards. However, in countries like Colombia, where the use of Chlorpyrifos is widespread, the number of investigations on the dynamics and risk involved in the presence of this class of substances in water bodies is limited.

Simulation of spreading of non-conservative passive substances in water bodies

Numerical modeling has become an indispensable tool for solving various physical problems. In this context, two fundamentally different approaches to the derivation of equations describing the motion of a liquid and the transfer of both conservative and non-conservative substances that have or do not affect the flow structure. In addition to the classical approach, in which the hydrodynamic equations of the baroclinic fluid are obtained from the Reynolds equations by introducing the assumption that the turbulent viscosity between jets is neglected, there is another approach, which is to introduce a certain scale of consideration, as well as the use of hypotheses about the magnitude of turbulent viscosity and small changes of flow characteristics along with horizontal coordinates as compared with the changes along with vertical one. Thus, there is the option to obtain similar equations allowing to numerically simulating unsteady flows with fixed boundary conditions (fluctuating streams). Also, the article discusses an approach to numerical simulation of biogenic substances as well as the chemical and biological processes in reservoirs.

Совершенствование методики оценки гетеротрофной активности пресноводных бактерий. Вопросы качества воды

The article describes an improved and approved methodology for assessing the heterotrophic activity of freshwater bacteria using a specific example. Namely, the example of studying the bacterial consumption of organic matter excreted by algae. Utilization of organic substances in water bodies by microorganisms and their oxidation are an important part of the functioning of aquatic ecosystems and water self-purification. This article details innovative modifications to the method based on the use of 14C-labeled organic matter by aquatic organisms. All these methods and techniques have been tested in the study of production and destruction processes in freshwater ecosystems of different trophic levels including mesotrophic, eutrophic and hypertrophic surface ecosystems.

ALGORITHM OF MANAGEMENT OF WATER-PROTECTIVE ACTIVITY OF JSC «SEGEZHA PPM» ON BASIS OF MATHEMATICAL MODELING

Modern environmental legislation of the Russian Federation requires the introduction of automated systems for the control of waste and natural waters for large water users, which include JSC «Segezha PPM». The article proposes an algorithm for integrating the current automated process control system of JSC «Segezha PPM» into a unified system of water safety management. The proposed automated control system contains sensors for monitoring the parameters of the production process, the parameters of biological sewage treatment plants, wastewater and Lake Vygozer in the background section. The process of managing water protection activities is based on the use of neural networks, an event tree, and models of convective-diffusive transfer and transformation of substances in water bodies. The implementation of the system will ensure the environmental quality standards of the water body, optimally redistribute the load between water outlets, optimize the parameters of the production process, and form model forecasts of the state of Lake Vygozero.

PBT assessment under REACH: Screening for low aquatic bioaccumulation with QSAR classifications based on physicochemical properties to replace BCF in vivo testing on fish

Aquatic bioconcentration factors (BCFs) are critical in PBT (persistent, bioaccumulative, toxic) and risk assessment of chemicals. High costs and use of more than 100 fish per standard BCF study (OECD 305) call for alternative methods to replace as much in vivo testing as possible. The BCF waiving scheme is a screening tool combining QSAR classifications based on physicochemical properties related to the distribution (hydrophobicity, ionisation), persistence (biodegradability, hydrolysis), solubility and volatility (Henry's law constant) of substances in water bodies and aquatic biota to predict substances with low aquatic bioaccumulation (nonB, BCF<2000).The BCF waiving scheme was developed with a dataset of reliable BCFs for 998 compounds and externally validated with another 181 substances. It performs with 100% sensitivity (no false negatives), >50% efficacy (waiving potential), and complies with the OECD principles for valid QSARs. The chemical applicability domain of the BCF waiving scheme is given by the structures of the training set, with some compound classes explicitly excluded like organometallics, poly- and perfluorinated compounds, aromatic triphenylphosphates, surfactants. The prediction confidence of the BCF waiving scheme is based on applicability domain compliance, consensus modelling, and the structural similarity with known nonB and B/vB substances.Compounds classified as nonB by the BCF waiving scheme are candidates for waiving of BCF in vivo testing on fish due to low concern with regard to the B criterion. The BCF waiving scheme supports the 3Rs with a possible reduction of >50% of BCF in vivo testing on fish. If the target chemical is outside the applicability domain of the BCF waiving scheme or not classified as nonB, further assessments with in silico, in vitro or in vivo methods are necessary to either confirm or reject bioaccumulative behaviour.

Corrections for matrix effects on fluorescence measurement of a multi-platform optical sensor

The LEDIF (LED-induced fluorescence) is an in situ optical instrument that utilizes fluorescence, absorbance, and scattering to identify and quantify substances in water bodies. In this study, matrix effects on fluorescence signals caused by inner filtering, temperature, intramolecular deactivation, turbidity, and pH were investigated, and compensation equations developed to correct measured values and improve accuracy. Multiple simultaneous matrix effect corrections were demonstrated with a laboratory sample subjected to known interferences and physical conditions. In general, compensation was found to be important to improve the accuracy of fluorescence measurements.