Municipal sewage treatment plants (STPs) are thought to be important point sources of microplastics in freshwater systems and many peer-reviewed articles have been published on this issue since mid-2010s. In this review, we summarize existing literature on the occurrence of microplastics in STPs and experimental methods used for isolation and identification of microplastics. The number concentrations of microplastics in STP influents were 15.1-640 L⁻¹, whereas those in the STP effluents were highly variable and ranged from not detectable to 65 L⁻¹. For most of cases, conventional STPs are removing microplastics very effectively. Fragments and fibers are dominant shapes of microplastics. Thermoplastics (polyethylene and polypropylene) and polyester are the predominant materials recovered. Although further research is needed, size distribution of microplastics in STPs is likely to follow a power law, implying that different studies using different size cutoffs may be compared after establishing a power law relationship.
Fresh Water ; Jurisprudence ; Polyesters ; Sewage*

Municipal sewage treatment plants (STPs) are thought to be important point sources of microplastics in freshwater systems and many peer-reviewed articles have been published on this issue since mid-2010s. In this review, we summarize existing literature on the occurrence of microplastics in STPs and experimental methods used for isolation and identification of microplastics. The number concentrations of microplastics in STP influents were 15.1-640 L⁻¹, whereas those in the STP effluents were highly variable and ranged from not detectable to 65 L⁻¹. For most of cases, conventional STPs are removing microplastics very effectively. Fragments and fibers are dominant shapes of microplastics. Thermoplastics (polyethylene and polypropylene) and polyester are the predominant materials recovered. Although further research is needed, size distribution of microplastics in STPs is likely to follow a power law, implying that different studies using different size cutoffs may be compared after establishing a power law relationship.
Fresh Water ; Jurisprudence ; Polyesters ; Sewage

Worldwide, several regions suffer from water scarcity and contamination. The infiltration and subsurface storage of rain and river water can reduce water stress. Artificial groundwater recharge, possibly combined with bank filtration, plant purification and/or the use of subsurface dams and artificial aquifers, is especially advantageous in areas where layers of gravel and sand exist below the earth's surface. Artificial infiltration of surface water into the uppermost aquifer has qualitative and quantitative advantages. The contamination of infiltrated river water will be reduced by natural attenuation. Clay minerals, iron hydroxide and humic matter as well as microorganisms located in the subsurface have high decontamination capacities. By this, a final water treatment, if necessary, becomes much easier and cheaper. The quantitative effect concerns the seasonally changing river discharge that influences the possibility of water extraction for drinking water purposes. Such changes can be equalised by seasonally adapted infiltration/extraction of water in/out of the aquifer according to the river discharge and the water need. This method enables a continuous water supply over the whole year. Generally, artificially recharged groundwater is better protected against pollution than surface water, and the delimitation of water protection zones makes it even more save.
Filtration ; Fresh Water ; analysis ; Water Purification ; instrumentation ; methods ; Water Supply

Compared to their terrestrial and marine counterparts, little is known about the capacity of freshwater-derived actinomycete bacteria to produce novel secondary metabolites. In the current study, we highlight the disparities that exist between cultivation-independent and -dependent analyses of actinomycete communities from four locations in Lake Michigan sediment. Furthermore, through phylogenetic analysis of strains isolated from these locations, we identified a Streptomyces sp., strain B025, as being distinct from other Streptomyces spp. isolated from sediment. Upon fermentation this strain produced a rare class of eight-membered lactone secondary metabolites, which have been for their antitumor properties. We used spectroscopic and chemical derivitization techniques to characterize octalactin B (1) in addition to its corresponding novel, unnatural degradation product (2).
Bacteria ; Fermentation ; Fresh Water ; Lakes ; Michigan ; Streptomyces*

Ten fresh water fish species (Hypothalmichthys molitrix, Tilapia mossambica, Mylopharyngodon piceus, Cirrhina molitorella, Squaliobabus curriculus, Cyprinus carpio, Carassius carassius, Ophicephatus, Pluta alba, Clarias fuscus) collected from five markets in Ha Noi city: Dang Tran Con (Dong Da district), North Thanh Xuan (Thanh Xuan district), Thanh Cong (Ba Dinh district), Van Dien (Thanh Tri district), and Phung Khoang (Tu Liem district) were examined for Clonorchis metacercaria and Gnathostoma larvea. Seven species were found to be infected with Clonorchis metarcecaria and only eels (Fluta alba) infected with Gnathostoma larvae. The samples of Clonorchis sp metacercaria were identified as Clonorchis sinensis and Gnathostoma larvae as Gnathostoma spinigerum
Clonorchis sinensis ; Larva ; Gnathostoma ; fishes ; Fresh Water

PURPOSE: In order to lower the infection rate and the reinfection rate of Clonorchiasis in high-risk areas, we performed and analyzed a case management on people with chlonorchisis. METHODS: The data was collected from April 2010 to March 2011. A community health practitioner was selected as a case manager based on our training program. The intervention group had 58 participants with three months of case management and the control group had 144 participants handled with traditional methods. RESULTS: The pre and post-test in the intervention group and the control group showed us improved knowledge of Clonorchiasis, attitudes and behavior toward eating freshwater fish. The results of post-test between the intervention group and the control group showed statistically significant differences in all categories, except a hand-washing category. However, one year after a case management, there was no significant difference in the failure rate of treatment. CONCLUSION: The case management was effective for people infected with Clornorchiasis near riverside areas; however, in order to lower the rates of reinfection and treatment failure, it is necessary to perform continuous monitoring and regular evaluations.
Case Management ; Clonorchiasis ; Eating ; Fresh Water ; Parasites ; Treatment Failure

Death by drowning is a major cause of unnatural death worldwide. It is therefore important to conduct forensic examination of immersed bodies following drowning, in order to determine the diagnosis of drowning, because no specific methods have been established thus far. Therefore, we performed a series of rat experiments to compare autopsy findings between seawater and fresh water drowning cases, which included the presence of pleural effusion and histologic findings of the lung. The results showed that the volume of pleural effusion increased in the seawater drowning group compared to the fresh water drowning group, and the total weight of lung was affected by the type of drowning medium and postmortem interval. However, histologic findings of the lung showed no significant difference between the 2 types of drowning mediums.
Animals ; Autopsy ; Drowning ; Fresh Water ; Lung ; Pleural Effusion ; Rats ; Seawater

The prevalence of cercarial infection in freshwater snails and their evolutionary trends were studied in Nakhon Nayok province, Thailand. A total of 2,869 individual snails were examined for parasitic infections. The results showed that 12 snail species were found to host larval stages of trematodes with an overall prevalence of 4.7%. The infected specimens included 7 types at the cercarial stage; cercariae, megalurous cercariae, echinostome cercariae, furcocercous cercariae, parapleurolophocercous cercariae, virgulate cercariae, and xiphidiocercariae. Regarding molecular identification, ITS2 sequence data of each larval trematode were analyzed, and a dendrogram was constructed using the neighbor-joining method with 10,000 replicates. The dendrogram was separated into 6 clades (order/family), including Echinostomatida/Echinostomatidae, Echinostomatida/Philophthalmidae, Opisthorchiida/Heterophyidae, Plagiorchiida/Prosthogonimidae, Plagiorchiida/Lecithodendriidae, and Strigeatida/Cyathocotylidae. These findings were used to confirm morphological characteristics and evolutionary trends of each type of cercariae discovered in Nakhon Nayok province. Furthermore, this investigation confirmed that the ITS2 data of cercariae could be used to study on phylogenetic relationships or to determine classification of this species at order and/or family level when possible.
Cercaria* ; Classification ; Fresh Water* ; Humans ; Methods ; Prevalence ; Snails* ; Thailand*

During a survey of fungal diversity of the order Mucorales, three zygomycete isolates, CNUFC-YR113-1, CNUFC-KNU16-7, and CNUFC-BS1-1 were isolated from freshwater and soil samples in Korea. The strains were analyzed both morphologically and phylogenetically based on internal transcribed spacer and 28S rDNA gene sequences. Based on their morphology and phylogeny, the CNUFC-YR113-1 and CNUFC-KNU16-7 isolates were identified as Actinomucor elegans, and CNUFC-BS1-1 was identified as Mucor minutus. To the best of our knowledge, the species A. elegans and M. minutus, belonging to an undiscovered taxon, have not been previously described in Korea.
DNA, Ribosomal ; Fresh Water ; Korea* ; Mucor* ; Mucorales ; Phylogeny ; Soil

In a survey of undiscovered taxa in Korea, three zygomycete fungal strains–EML-W31, EML-HGD1-1, and EML-RUS1-1–were isolated from freshwater, grasshopper fecal, and soil samples in Korea. On the basis of the morphological characteristics and phylogenetic analysis of internal transcribed spacer and 28S rDNA, the isolates of EML-W31, EML-HGD1-1, and EML-RUS1-1 were confirmed to be Cunninghamella bertholletiae, Cunninghamella echinulata, and Cunninghamella elegans, respectively. These species have not been previously described in Korea.
Bertholletia* ; Cunninghamella* ; DNA, Ribosomal ; Fresh Water ; Fungi* ; Grasshoppers ; Korea* ; Soil