Superwetting Ag/α-Fe_(2)O_(3) anchored mesh with enhanced photocatalytic and antibacterial activities for efficient water purification

Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation.However,it is still a challenge to fabricate multifunctional and environmentally friendly materials,which can be stably applied to purify the actual complicated wastewater.Here,a Ag/Ag/α-Fe_(2)O_(3) heterostructure anchored copper mesh was intentionally synthesized using a facile two-step hydrothermal method.The resultant mesh with superhydrophilicity and underwater superoleophobicity was capable of separating various oil/water mixtures with superior separation efficiency and high permeationflux driven by gravity.Benefiting from the joint effects of the smaller band gap of Ag/α-Fe_(2)O_(3) heterojunction,inherent antibacterial capacity of Ag/α-Fe_(2)O_(3) and Ag nanoparticles,favorable conductive substrate,as well as the hierarchical structure with superwettability,such mesh presented remarkably enhanced degradation capability toward organic dyes under visible light irradiation and antibacterial activity against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)compared with the pure Ag/α-Fe_(2)O_(3) coated mesh.Impressively,the mesh exhibited bifunctional water purification performance,in which organic dyes were eliminated simultaneously from water during oil/water separation in onefiltration process.More importantly,this mesh behaved exceptional chemical resistance,mechanical stability and long-term reusability.Therefore,this material with multifunctional integration may hold promising potential for steady water purification in practice.

DNA barcoding of fishes from Zhoushan coastal waters using mitochondrial COI and 12S rRNA genes

Accurate species identification is a key component of biodiversity research.DNA barcoding is an effective molecular method used for fish species identification.We aimed to study the DNA barcoding of fish in Zhoushan coastal waters,explore the differences and applicability of two gene fragments(12S rRNA and COI)of DNA barcoding in fish species identification,and established a comprehensive fish barcoding reference database.Two hundred and eighty-seven captured fish samples from Zhoushan coastal waters were identified using morphological characteristics and DNA barcoding.A total of 26412S rRNA sequences(belonging to eight orders,31 families,55 genera,and 66 species)and 188 COI sequences(belonging to seven orders,30 families,48 genera,and 58 species)were obtained.The lengths of the 12S rRNA sequences ranged from 165 to 178 bp,and the guanine-cytosine(GC)content was 45.37%.The average 12S rRNA interspecific and intraspecific genetic distances(K2P)were 0.10%and 26.66%,respectively.The length of the COI sequence ranged 574–655 bp,and the content of GC was 45.97%.The average 12S rRNA interspecific and intraspecific genetic distances(K2P)were 0.16%and 27.45%,respectively.The minimum interspecific genetic distances of 12S rRNA and COI(1.23%and 1.86%)were both greater than their maximum intraspecific genetic distances(2.42%and 8.66%).Three molecular analyses(NJ tree,ABGD,and GMYC)were performed to accurately identify and delineate species.Clustering errors occurred when the 12S rRNA sequences were delimited using the NJ tree method,and the delimitation results of ABGD and GMYC are consistent with the final species identification results.Our results demonstrate that DNA barcoding based on 12S rRNA and COI can be used as an effective tool for fish species identification,and 12S rRNA has good application prospects in the environmental DNA(eDNA)metabarcoding of marine fish.

Fishing Dynamic and Stock Status of Endeavour Shrimp(Metapenaeus ensis de Haan)in Bombana Waters,South-East Celebes

The high market demand for endeavour shrimp(Metapenaeus ensis de Haan)has caused intensive fishing for this resource and tends to threaten their sustainability.Assessment of fishing dynamic and stock status of fisheries resource is the main point to formulate its proper sustainable management in the future.The purpose of this study was to determine the stock status of endeavour shrimp in the Bombana and its surrounding waters.The study was conducted from April to November 2021 using a survey method to analyze the length at first capture(L_(c)),length at first maturity(L_(m)),growth rate(K),maximum theoretical carapace length(Loo),and mortality rate such as total mortality rate(Z),fishing mortality rate(F)and natural mortality rate(M).The study results revealed that the endeavour shrimp growth pattern in Bombana was negative allometric and that the ratio of males and females was not balanced.The length at first capture(L_(c))was 29.83 mm(carapace length)and the length at first maturity(L_(m))was at a total carapace length of 31.67 mm.The growth rate(K)was 1.0 per year and maximum theoretical length(L_(∞))was 46.2 mm.The estimate total mortality rate(Z)was 2.52 per year,the fishing mortality rate(F)and natural mortality rate(M)were 0.91 per year and 1.61 per year respectively.The exploitation rate(E)was 0.36 per year,therefore the stock status is not categorized overfishing.In order to ensure the sustainability of the endeavour shrimp,then the effort must be increased by about 28%of the current effort.

The progress of catalytic technologies in water purification:A review

Catalytic technologies have been paid increasing attention in refractory pollutants abatement due to its practical and potential values in water purification. As effective and efficient approaches for water purification, Fenton＇s reagent, ozonation, electrochemical and photocatalytic methods have been widely studied and applied in different aspects and have been reviewed by several articles. In recent years, some novel catalytic processes based on above processes have been developed for enhancing the efficiency of removing the organics from water. This review emphasized on the recent development of heterogeneous catalytic ozonation, electrocatalysis in respect of novel electrodes and electro-Fenton method, photoelectrocatalysis process and photoelectron-Fenton in water purification. It was also an attempt to propose general ideas about mechanism and principle enhancing the catalytic efficiency for the degradation and the mineralization of organics in water.

Relationship Between the Spatiotemporal Distribution of Dominant Small Pelagic Fishes and Environmental Factors in Mauritanian Waters

The relationship between the spatiotemporal distribution of three dominant small pelagic fishes,including chub mackerel(Scomber japonicus),horse mackerel(Trachurus trecae)and round sardinella(Sardinella aurita),and the environmental factors in Mauritanian waters were analyzed by using 4 years of logbook data of commercial purse seine fisheries to improve the efficiency of fishery and management of sustainable exploitation.A Tweedie-generalized additive model(GAM)of 8-day average catches and the monthly geostatistical analysis of daily catches were used in this study to analyze the influence of environmental factors on catch per unit of effort(CPUEs)and to map the spatial distribution of three mixed dominant small pelagic fishes,respectively.A 10'×10' grid was used,and environmental factors were processed from remote sensing,including 8-day average sea surface temperature(SST),the nearest distance between SST fronts and CPUE position(Df),chlorophyll-a(Chl-a)concentration,salinity,and eddy kinetic energy.Results showed that 1)the distribution of three dominant small pelagic fishes might be related to the intensity of upwelling in Mauritanian waters;2)oceanic fronts might play a key role in the ecology of chub mackerel,horse mackerel,and round sardinella;3)Chl-a concentration might be associated with the feeding grounds of chub mackerel;4)the target species distribution appeared sensitive to gradient changes in the amount of salinity;5)three zones(northern,central,and southern)with variable abundances were delineated;and 6)a high concentration of the center of gravity in the central zone might be related to the strong upwelling of nutrient-rich waters.This study can provide new insights to enhance the fishery efficiency and sustainable exploitation management of purse seiners in certain area off Mauritania.

Presence of Acanthamoeba spp.in water purification plants in southern England

Objective:To identify the prevalence of Acanthamoeba in drinking water treatment plants during the course of the purification processes.Methods:Samples were taken from two drinking water purification plants and monitored for the presence of Acanthamoeba in order to estimate the removal capacity of treatment methods employed. Water samples were collected at each step in the purification,during the one year survey,and analysed for the presence of Acanthamoeba spp.by plating on bacterial-seeded plates.Results:The results showed that amoebae were present in surface raw waters in 100%of the samples tested.Acanthamoeba spp.were isolated from 71%and 57%of the water samples collected from post flat-bottom clarifier 1 and post-sedimentation plant respectively.Considering the outflow drinking waters,the removal capacity was 100%in both purification plants monitored.The occurrence of Acanthamoeba was not associated with seasonality.Conclusion: These findings confirm that water purification plants employing methods of flocculation,sedimentation,and filtration in combination with activated charcoal filtration,ozonisation and chlorination exhibited sufficient Acanthamoeba removal capacity and the presence of amoebae in the tap water may be due to older plumbing,water storage tanks,tap water hygiene,and/or environmental settings.

Determination of the Contents of EPA and DHA and Lipid Constituents in Main Fresh Water Fishes in China

In this study the molecular formula and structure of lipid constituents of silver carp and bighead carp in middle reaches of Yangtze River were determined by gas chromatography-mass spectrometry. The position of double bounds was identified by the method of double bounds chemical localization. These carps are proved to contain eicosapantaenoic acid (EPA) and decosahexenoic acid (DHA). The contents of EPA and DHA, which were determined by gas chromatography, in silver carp and bighead carp were approximately the same as in tuna and salmon. The contents of EPA and DHA in 100 g wet sample were 0. 187 g, 0. 229 g and 0. 246 g, 0. 325 g respectively, but the cholesterol contents in silver carp and bighead carp were much lower than in tuna and salmon.

Supercritical Water Technology Applied to the Purification of Waters Contaminated by Toxic Micro-Polluting Organic Compounds

Purification of water contaminated by toxic organic compounds at low and very low concentration is a quite interesting challenge from both the technical and the economical point of view. In fact, the direct destruction of organic compounds dissolved in very diluted aqueous solution is very costly and hardly achievable. To overcome this problems it was studied and developed a new water purification process which is made of three steps: a) removal of the diluted and toxic polluting compounds by adsorption on activated carbon beds operating at ambient P ant T;b) regeneration of the exhausted carbon bed with supercritical water in order to obtain a mixture of water and polluting compounds signifi-cantly more concentrated than the contaminated liquid water;c) destruction of the toxic compounds in a continuous Supercritical Water Oxidation Reactor. Step a) was studied at laboratory scale in order to obtain all the required information for modeling the adsorption operation;step b) was modeled by using literature experimental data and, step c) was validated at pilot plant scale. In all the above mentioned steps, phenol was used as representative of polluting compounds.

Influence of Wetland Self-purification Capacity on the Utilization of Water Resources——A Case Study of the Project for Recycling Yanshan River Water

[ Objective] The study aims to resolve water resource problem availably. [ Method] On the basis of wetland self-purification capacity, Yanshan River water was purified by Xixi Wetland, and the feasibility of using treated Yanshan River water for urban greening and watering road was analyzed. [Result] Compared with direct utilization of tap water, it is more economic to recycle Yanshan River water purified by Xixi Wetland for urban greening and watering read, with obvious economic, ecological and social benefits, so it is an effective method to address shortage of water resources and is worth spreading. [ Conclusion] It is feasible to use Yanshan River water purified by Xixi Wetland for urban greening and watering read.

Synthesis of Geopolymers Using Local Resources for Construction and Water Purification

Large deposits of impure kaolins exist in Jordan and many parts of the world;geoplymers can reduce environmental impacts and have multi-application in many fields, such as water purification, waste treatment, fire proof construction, etc. The aim of this research is to investigate the use of alkali activated zeolitic tuff and low purity metakaolin as precursors for the production of functional geoplymers exhibiting proper mechanical properties and high potential for water storage and decontamination of polluted solutions. The results confirmed that this type of geopolymers showed superior mechanical characteristics and higher adsorption capacity towards heavy metals such as Cu(II) ions, which was similar to natural zeolite. X-ray diffraction analysis showed that phillipsite, a major zeolite mineral, disappeared upon geopolymerization, while scanning electron microscopy analysis showed that geopolymers exhibit a porous matrix of nano-particles. The geopolymers have also displayed high compressive strength and tensile bending strength of about 7.8 MPa and 45 MPa respectively, compared to reference geopolymers. This functional-geopolymers indicate that they are efficient, cost effective and have a potential for number of applications including construction, water storage and wastewater treatment.

The Occurrence and Prevention of Filamentous Algae in Ecological Purification System of Micro-polluted Water

[ Objective ] The aim was to study the influence of filamentous algae on the process of water ecological purification. [ Method ] The occurrence mechanism of filamentous algae and its ecological system were summarized and analyzed. Considering the ecological purification in north- ern Jiangsu, the occurrence and prevention of filamentous algae in water, the method to prevent filamentous algae in polluted water was discussed. [ Result] The results showed that by measures of improving planting density, regular harvesting, and water flow state control before the filamentous algae blooming period, together with improving local pH value, light interference and ecological control during the blooming period, can effectively control the filamentous algae blooming. [ Condusion] The study of the happening mechanism of filamentous algae provided theoretical references and the technical basis in the work of filamentous algae prevention and control.

Water Purification Capacity of Four Kinds of Aquatic Plants in the Upper Reaches of Luanhe River

Under artificially simulated conditions, the water purification effects of Lythrum salicaria, Typha minima, Scirpus validus, Iris wilsonii and their configurations were studied. The results showed that various aquatic plants and their configurations showed purification effects for total nitrogen(TN), nitrate nitrogen(NO_3^-), total phosphorus(TP), orthophosphate(PO_4^(3-)) and chemical oxygen demand(COD) in water body, and the purification effects of aquatic plant configurations were better than those of single ones. Regression analysis was conducted for dynamics of various water quality indicators. The removal rates of TN and COD within 50 d by the combination of L. salicaria and I. wilsonii were 73.83% and 77.4%, respectively, with the best purification effect; the removal rate of NO_3^- within 20 d by the combination of S. validus and I. wilsonii was 89.41%; and the combination of S. validus and I. wilsonii showed the best removal effect for TP and PO43-, of which the 50-d removal rates were 88.98% and 92.39%, respectively. Reasonable choice of local aquatic plants and their optimal combinations can be applied in the improvement of water quality of rivers.

The Status Quo of Industrial Development of Cold Water Fishes in Henan Province

This article first analyzes the status quo of industrial development of cold water fishes in Henan Province. And then it points out the main problems in the process of cold water fish industrialization as follows: the parent fish rearing of cold water fishes and the supply of roe and fry are inadequate; the demand for feed nutrition,research and development of disease prevention and control technology lag behind. In order to provide scientific basis for promoting the industrial independent innovation and international competitiveness,finally the following ideas and recommendations for industrial development of cold water fishes are put forward: strengthening policy support for the enterprises,and striving to create the leading enterprises,to achieve dramatic development; implementing the strategy of developing fishery by relying on science and technology,promoting the industrial independent innovation and competitiveness; creating specialized cooperative organizations,actively improving the supporting system,and expanding the space for development of the industry.

Biocontamination in Metal Traces (Pb, Cd) of Waters, Sediments and Fish from Urban and Periurban Marine Perimeters in the Community of Lokossa in Benin

In Benin, market gardening has become a new profession and plays an important role in the supply of fresh vegetables. In the coastal regions, fish farming is practiced on the outskirts of market gardening sites. However, poorly regulated cultivation practices and increasing pollution do not necessarily guarantee the sanitary quality of the products delivered. This study aims to evaluate the physico-chemical qualities of the water used for watering and, secondly, the lead and cadmium contamination of the water used for watering, the soil (sediment) and the fish products (fish) on the urban market gardening perimeter in the commune of Lokossa in Benin. These various samples taken for this purpose were analysed at the Ministry of Health’s Water and Food Quality Control Laboratory. We noted pollution of organic elements through the physico-chemical parameters measured such as temperature, NTK, COD, BOD and total phosphorus and confirmed by average lead and cadmium levels of 0.42 mg/L in water, 0.52 mg/L in sediment and 0.31 mg/L to 0.76 mg/L in fish tissue (Carp and Catfish) for lead and 0.07 mg/L in water, 0.1 mg/L in sediment and 0.5 mg/L in fish for cadmium. These rates are well above the normal values accepted by the GESAMP, PNEC INERIS and FAO standards. The consequences of this contamination are health risks for consumers.

Effect of Digested Sewage Sludge on the Ventilation and Coughing Rates of Two Fresh Water Fish

Addition of digested sewage sludge at concentrations of 2% and 10% (v/v) to the water increased coughing rate in big head and tilapia (P<0.05). Ventilation rate was significantly decreased (P<0.05) in big head and tilapia at sludge concentrations of 6% and 2% (v/v)respectively. Copper (Cu), cadmium (Cd) and zinc (Zn) are trace metals which are commonly found in sludge. Cu caused a significant increase (P<0.05) in coughing rate in both tilapia and big head at concentrations of 0.3 and 0.2 μg/ml respectively. Zn caused significant increase (P<0.05) in coughing rate only in big head at 2 μg/ml. Neither fish responded to Cd of up to 2μg/ml in the water. However, when the levels of these trace metals in the digested sludge were measured, they were below that which can cause significant changes in the respiratory movements. Therefore, the changes in ventilation and coughing rates after addition of sludge may be due to the presence of substances other than these metals. The results of this experiment provides a guideline to control the level of sludge that can be used in rearing these fresh water fish in ponds

Clean and Safe Supply of Fish and Shellfish to Clear the HACCP Regulation by Use of Clean and Cold Deep Ocean Water in Rausu,Hokkaido,Japan

For the supply of fish and shellfish to consumers in fresh condition, clean handling after catch from the sea is es-sential. According to HACCP (Hazard Analysis and Critical Control Points), it is important to meet such requirement bykeeping fish and shellfish under a certain low temperature and clean conditions after catching. The deep ocean water(DOW) characterized by low temperature and cleanliness has been chosen for fish and shellfish handlings, particularly forsalmon, cod, and sea urchin in Town ’Rausu’ in Hokkaido, Japan. DOW below 2.9°C of an amount of nearly 5 000m3 isplanned to be pumped up every day from a depth of about 350 m, and temporarily stored in a large simulated tank on land.DOW is then supplied to fish boats through hydrants distributed throughout the harbor and used for keeping salmon in cleanand cold conditions. Ice made from DOW is also used for lowering temperature if necessary. DOW and ice made from DOWare also used during the transportation of fish and shellfish. The entire system is scheduled to be completed by the summer of2005.

Influence of Management on the Water Quality and Sediment in Tropical Fish Farm

A seven-month research evaluated the management effect on the water quality and sediment of seven fish ponds. Water and sediment were collected at nine sample sites: seven in the fish ponds;one in inlet water and another in the fish farm’s effluent. The soil samples were analyzed for macro- and micro-nutrients and the water samples were analyzed for physical and chemical parameters. Management and local climate conditions affected nutrient seasonality in the sediment and featured high concentrations of Al, Ca, Cu, K, Mg, C, Na, Zn and OM at the effluent with low pH, ranging between 4.4 and 6.5. Sudden decrease of DO (less than 3 mg/L) during the rainy season, with a 180 mmrainfall, and a TSS increase (approximately 10 mg/L) were reported. Use of organic manure in fish pond V6 caused higher rates of ammonia (over 1 mg/L). Due to the sediment’s acid pH (less than 4.8) and Al at 0.92 mg/L at the effluent, great care was required in the fish farm. Maintenance and procedures management in the fish farm under analysis should be given more attention since high levels of Al, Fe and acid pH and low levels of potassium and phosphorus in the sediment may produce unfavorable conditions in the water column, and may ultimately have an impact on fish.

Green Liver Systems for Water Purification:Using the Phytoremediation Potential of Aquatic Macrophytes for the Removal of Different Cyanobacterial Toxins from Water

The protection and reasonable use of freshwater is one of the main goals for our future, as water is most important for all organisms on earth including humans. Due to pollution, not only with xenobiotics, but also with nutrients, the status of our water bodies has changed drastically. Excess nutrient load induces eutrophication processes and, as a result, massive cyanobacterial blooms during the summer times. As cyanobacteria are known to produce several toxic secondary metabolites, the so-called cyanotoxins, exhibiting hepato-, neuro- and cell-toxicity, a potential risk is given, when using this water. There is an urgent need to have a water purification system, which is able to cope with these natural toxins. Using aquatic plants as a Green Liver, the Green Liver System?, was developed, able to remove these natural pollutants. To test the ability of the Green Liver System?, several cyanobacterial toxins including artificial and natural mixtures were tested in a small-scale laboratory system. The results showed that within 7 - 14 days a combination of different aquatic macrophytes was able to remove a given toxin amount (10 μg·L-1) by 100%. The phytoremediation technology behind the Green Liver Systems? uses the simple ability of submerged aquatic plants to uptake, detoxify and store the toxins, without formation and release of further metabolites to the surrounding water.

Drinking water safety and the development of purification technology

This paper briefly introduced the evolution of purification technology for drinking water over time. After description of the 1st generation processes in the beginning of the 20th century - conventional processes and the 2nd generation processes in 1970s - advanced treatment processes, a tertiary processes - UF (ultrafiltration) based on integrated processes was proposed. Moreover, reaction measures (dosing variety of regents for different contaminants) for urban source water emergencies were illustrated in brief. A new technology of KMnO4 and potassium permanganate composite (PPC) for drinking water purification which was developed by Harbin Institute of Technology (HIT) was concisely introduced.