Rapid screening for ecotoxicity of plating and semiconductor wastewater employing the heartbeat of Daphnia magna

A critical review on quantitative evaluation of aqueous toxicity in water quality assessment

Conventional chemical techniques have inherent limitations in detecting unknown chemical substances in water. As a result, effect-based methods have emerged as a viable alternative to overcome these limitations. These methods provide more accurate and intuitive evaluations of the toxic effects of water. While numerous studies have been conducted, only a few have been applied to national water quality monitoring. Therefore, it is crucial to develop toxicity evaluation methods and establish thresholds based on quantifying toxicity. This article provides an overview of the development and application of bioanalytical tools, including in vitro and in vivo bioassays. The available methods for quantifying toxicity are then summarized. These methods include aquatic life criteria for assessing the toxicity of a single compound, comprehensive wastewater toxicity testing for all contaminants in a water sample (toxicity units, whole effluent toxicity, the potential ecotoxic effects probe, the potential toxicology method, and the lowest ineffective dilution), methods based on mechanisms and relative toxicity ratios for substances with the same mode of action (the toxicity equivalency factors, toxic equivalents, bioanalytical equivalents), and effect-based trigger values for micropollutants. The article also highlights the advantages and disadvantages of each method. Finally, it proposes potential areas for applying toxicity quantification methods and offers insights into future research directions. This review emphasizes the significance of enhancing the evaluation methods for assessing aqueous toxicity in water quality assessment.

Improving the Accuracy of a Biohybrid for Environmental Monitoring

Environmental monitoring should be minimally disruptive to the ecosystems that it is embedded in. Therefore, the project Robocoenosis suggests using biohybrids that blend into ecosystems and use life forms as sensors. However, such a biohybrid has limitations regarding memory-as well as power-capacities, and can only sample a limited number of organisms. We model the biohybrid and study the degree of accuracy that can be achieved by using a limited sample. Importantly, we consider potential misclassification errors (false positives and false negatives) that lower accuracy. We suggest the method of using two algorithms and pooling their estimations as a possible way of increasing the accuracy of the biohybrid. We show in simulation that a biohybrid could improve the accuracy of its diagnosis by doing so. The model suggests that for the estimation of the population rate of spinning Daphnia, two suboptimal algorithms for spinning detection outperform one qualitatively better algorithm. Further, the method of combining two estimations reduces the number of false negatives reported by the biohybrid, which we consider important in the context of detecting environmental catastrophes. Our method could improve environmental modeling in and outside of projects such as Robocoenosis and may find use in other fields.

Defining Quality Criteria for Nanoplastic Hazard Evaluation: The Case of Polystyrene Nanoplastics and Aquatic Invertebrate Daphnia spp

Polystyrene nanoparticles are the most investigated type of nanoplastics in environmental hazard studies. It remains unclear whether nanoplastic particles pose a hazard towards aquatic organisms. Thus, it was our aim to investigate whether the existing studies and data provided therein are reliable in terms of data completeness. We used the example of Daphnia spp. studies for the purpose of polystyrene nanoplastic (nanoPS) hazard evaluation. First, a set of quality criteria recently proposed for nanoplastic ecotoxicity studies was applied. These rather general criteria for all types of nanoplastics and different test organisms were then, in the second step, tailored and refined specifically for Daphnia spp. and nanoPS. Finally, a scoring system was established by setting mandatory (high importance) as well as desirable (medium importance) criteria and defining a threshold to pass the evaluation. Among the existing studies on nanoPS ecotoxicity for Daphnia spp. (n = 38), only 18% passed the evaluation for usability in hazard evaluation. The few studies that passed the evaluation did not allow for conclusions on the hazard potential of nanoPS because there was no consensus among the studies. The greatest challenge we identified is in data reporting, as only a few studies presented complete data for hazard evaluation.

Treatment of electropolishing industrial wastewater and its impact on the immobilisation of Daphnia magna

The amount of industrial pollution entering the environment and its impact on living organisms is an ongoing concern. At the same time, due to an increasing awareness, new methods of wastewater treatment are being explored that are not only effective but also environmentally acceptable. Meeting environmental standards for permitted concentrations is a necessity, but investigating the effects of wastewater on living organisms is also an important issue. In this paper, the influence of metal ions (Fe(III), Cr(III), Ni(II), Cu(II)) in industrial wastewater from electropolishing of stainless steel on Daphnia magna has been investigated. Daphnids have been exposed to wastewater both before and after treatment (Ca(OH)₂ precipitation, sorption with peat). Immobilisation in a 48-h acute toxicity test and EC₅₀ has been determined. In the case of studied industrial wastewater, the organic content (expressed as total organic carbon) of the effluent has a positive impact in terms of the survival of D. magna and increases the range of heavy metal concentrations tolerated by them. The application of a two-stage process with Ca(OH)₂ neutralisation followed by sorption with peat allows for the removal of almost 100% of metal ions from the wastewater. The reduction obtained ensured a limited impact on D. magna and a decrease in immobilisation to less than 10%. Proper execution of the wastewater treatment process ensures a reduction of its negative impact on living organisms.

Treatment of heavy metals containing wastewater using biodegradable adsorbents: A review of mechanism and future trends

The direct disposal of industrial effluents into the aquatic system is considered as a significant environmental hazard in many countries. Because of poisonous chemicals, substantial volumes of effluent release, as well as the lack of adequate of conventional treatment methodologies, industrial effluent treatment is extremely difficult. Numerous researchers have been interested in adsorption technology for its high efficiency of pollutant removal, low cost, and abundantly available adsorbent. Various adsorbent materials, both natural and modified form, have been widely used for the removal of toxic contaminants from industrial effluent. This paper highlights recent advancements in multiple modification types to functionalize the adsorbent material, resulting in higher adsorption capacity on various toxic pollutants. This review provides an overview of the adsorption mechanism and parameters (pH, adsorbent dosage, initial concentration, temperature and interaction time), which influencing the removal efficiency of adsorbents. Furthermore, this review compiles the desorption study to recover the adsorbent and improve the cycle's financial viability. This review provides a concise overview of the future directions and outlook in the framework of adsorbent application for industrial wastewater treatment.

Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS) in Surface Water of China: National Exposure Distributions and Probabilistic Risk Assessment

This study presents a comprehensive application of the probabilistic risk assessment methodology for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), which are two types of perfluoroalkyl acids frequently studied in recent years. The exposure characteristics of PFOA and PFOS in Chinese surface water on a nationwide scale were summarized. Individual predicted no-effect concentration (PNEC) and the sensitivities for taxonomic groups of primary producers, invertebrates, and vertebrates were derived by the species sensitivity distributions method. Both hazard quotients (HQs) and joint probability curves were calculated to assess the risks to aquatic organisms. Among seven Chinese river basins, the mean concentrations of PFOA and PFOS in the Yangtze River Basin were the highest (58 ng/L and 22 ng/L, respectively), while the lowest concentrations (< 1 ng/L) were in the Songhua River Basin. The acute PNEC value was 2.43 mg/L for PFOA and 0.96 mg/L for PFOS, and the chronic PNEC value was 0.0067 mg/L for PFOA and 0.0012 mg/L for PFOS, respectively. The sensitivities of different taxonomic groups revealed higher sensitivity of primary producers for PFOA and higher sensitivity of invertebrates for PFOS. The acute HQs of PFOA and PFOS were less than 1. The probabilities of exposure concentrations exceeding 5th percentile toxicity value of the chronic data for all aquatic organisms were 1.65% for PFOA and 1.23% for PFOS, respectively, suggesting a low probability of effects to aquatic organisms. Compared with the risk scenarios worldwide, the ecological risks for chronic effects decreased in the order of PFOS (worldwide) > PFOA (China) > PFOS (China) > PFOA (worldwide).

Physiological and Behavioral Effects of SiO2 Nanoparticle Ingestion on Daphnia magna

The increasingly widespread use of engineered nanoparticles in medical, industrial, and food applications has raised concerns regarding their potential toxicity to humans and the environment. Silicon dioxide nanoparticles (SiO2 NPs), which have relatively low direct toxicity, have been increasingly applied in both consumer products and biomedical applications, leading to significantly higher exposure for humans and the environment. We carried out a toxicity assessment of SiO2 NPs using the common water flea D. magna by focusing on physiological and behavioral indicators such as heart rate, swimming performance, and growth. Exposure to SiO2 NPs did not produce acute or chronic toxicity at limited concentrations (<100 μg/mL), but did have statistically significant negative effects on heart rate, swimming distance, and body size. The use of fluorescein isothiocyanate in a silica matrix allowed the tracing and visualization of clear SiO2 NP accumulation in D. magna, which was confirmed by ICP-MS. Although exposure to SiO2 NPs seemed to affect cardiac and swimming performance, such end-point experiments may be insufficient to fully understand the toxicity of these nanoparticles. However, the physiological and behavioral changes shown here suggest potential adverse effects on the aquatic environment by substances previously considered nontoxic.

Protective effect of surfactin on copper sulfate-induced inflammation, oxidative stress, and hepatic injury in zebrafish

Surfactin, an antibacterial peptide, produced by various Bacillus subtilis strains, have broad-spectrum antibacterial and immune-enhancing functions. In this study, we investigated the anti-inflammatory, antioxidant, and hepatoprotective effect of surfactin on zebrafish (Danio rerio) larvae following their exposure to copper sulfate (CuSO₄ ). The mature AB wild-type and a transgenic line of zebrafish larvae that expressed enhanced GFP (EGFP) named Tg (Lyz:EGFP) were exposed to 0, 20, 40, and 60 μg/mL surfactin after incubation with 3.2 μg/mL CuSO₄ for 2 h from 72 h postfertilization (hpf). Different endpoints, such as migration of GFP-labeled neutrophils, analysis of inflammatory cytokines and transaminases, markers of oxidation, expression of certain genes, and histological changes of liver, were studied to evaluate the function of surfactin. The protein expression levels of NF-κBp65, TNF-α, cyclooxygenase-2 (COX-2), and iNOS were determined in murine macrophage RAW 264.7 cells by western blotting. Our results show that surfactin reduced migration of neutrophils and relieved hepatic injury. In addition, surfactin reduced the index levels of inflammatory factors, oxidative stress response, and improved hepatic function. Surfactin also significantly inhibited the expression of IL-1β, IL-8, TNF-α, nitric oxide, NF-κBp65, COX-2, and iNOS, and increased the expression of IL-10. Thus, our results demonstrate that surfactin has anti-inflammatory, antioxidant, and hepatoprotective activities. Surfactin has potential as a novel inflammation and immune adjustment.

The release of contaminants from steel slags and natural aggregates: Evaluation of toxicity and genotoxicity

Steel slags (SS) are the major waste produced by iron and steel industry. Slags may be reused as recycled materials, instead of natural aggregates (NA), to reduce the final disposal in a landfill and the exploitation of raw materials. However, the reuse of SS may generate a potential release of toxic compounds for the environment and humans. The purpose of this study was to evaluate the toxicity and genotoxicity of SS, in comparison with NA, by using an integrated chemical-biological approach to enable their safe reuse in engineering applications. Leaching solutions from samples were obtained by using short-term leaching tests (CEN EN 12457-2, 2004) usually adopted for the evaluation of waste recovery and final disposal. Chemical analyses of leachates were performed according to the Italian legislation on waste recovery (Ministerial Decree 186/2006). The leaching solutions were assayed by using toxicity test on Daphnia magna. Moreover, mutagenicity/genotoxicity tests on Salmonella typhimurium, Allium cepa, and human leucocytes and fibroblasts were carried out. The releases of pollutants from all samples were within the limits of the Italian legislation for waste recovery. Despite the effects that SS and NA could have on different cells, in terms of toxicity and genotoxicity, globally, SS do not seem to be any more hazardous than NA. This ecotoxicological assessment, never studied before, is important for promoting further studies that may support the decision-making process regarding the use of such types of materials.

Wastewater treatment, reuse, and disposal-associated effects on environment and health

This paper presents the review of the literature published in the year 2019 related to treatment and reuse of wastewater and effects on the environment and human health. The scientific review on the treatment and reuse of wastewaters is divided into various sections in the paper. The review sections cover wastewater management, reuse, removal of microorganisms, and chemical constituents. Besides, the review also covers research focused on wastewater treatment plants, disposal, and the management of wastewater sludge as well as biosolids in the environment. PRACTITIONER POINTS: This paper highlights the review of scientific literature published in the year 2019.Review provide issues related to health risks associated with human and the general environment on the reuse of wastewater, treatment as well as disposal.The literature review covers selected papers relevant to the topic.