Water Suspended Matter Research Articles

Influence of Turbidity on Foraging Behaviour in Three-Spined Sticklebacks (Gasterosteus aculeatus)

Anthropogenic activities increase turbidity in coastal marine environments globally, and turbidity is particularly caused by eutrophication. Turbidity is a measurement of the scattering and absorption of light by suspended matter in water. An increase in turbidity influences visual predators and affects community structures and whole ecosystems. The three-spined stickleback (Gasterosteus aculeatus) is a widespread species in the northern hemispheric Pacific and Atlantic oceans. It is a visual predator and, therefore, a very well-suited species for studying the effects of increasing turbidity on foraging behaviour and activity. Sticklebacks used for this study were from an aquarium in the North Sea Oceanarium. They have been in the aquarium for around two months and were originally collected in a highly eutrophicated marine fjord system. They were individually placed in an observation aquarium, fed with krill, given 10 min to forage, and observed by video cameras. The video films were analysed to study stickleback predation behaviour. Experiments were repeated with four different turbidity treatments, ranging from a mean of 0.034 up to 10 NTU (nephelometric turbidity unit). Bentonite clay was used as a turbidity-increasing substance. A statistically significant difference in foraging behaviour and activity between the turbidity treatments was observed. The test subjects were found to lunge less for prey and had a higher feeding latency with increasing turbidity. Additionally, they were less active with increasing turbidity. The behavioural instability estimated as a variation in feeding latency increased with increasing turbidity but decreased at the highest turbidity value. Our study indicates an effect of turbidity-increasing events on the behaviour of the three-spined stickleback and potentially also other similar visual predators.

CONTACT CLARIFIERS IN DRINKING WATER TREATMENT PROCESSES

The article deals with the issues of resource-saving technology in the preparation of drinking water on contact clarifiers. One of the methods of water purification from coarse and colloidal contaminants is the method of contact coagulation using aluminum sulfate coagulant. It is advisable to use contact clarifiers in single-stage treatment schemes for low-turbid colored and cloudy-colored waters, when the total content of suspended solids in the water entering the contact clarifiers, including the suspension formed as a result of introducing reagents into the water, does not exceed 150 mg/l. With a higher content of suspended matter in water, the water consumption for washing contact clarifiers increases sharply. To intensify the preparation of drinking water on contact clarifiers, a resource-saving technology is proposed using contact clarifiers using a modified aluminum sulfate coagulant solution, which makes it possible to: reduce the consumption of coagulants used in water purification, improve the quality of water clarification by weighing substances, and reduce the cost of water treatment. Theoretical prerequisites for improving the operation of contact clarifiers with a modified coagulant solution are considered. The use of a modified coagulant solution allows, without deteriorating the quality of water clarification, to reduce the calculated doses of the coagulant by an average of 25-30%, which confirms the feasibility of using a modified aluminum sulfate coagulant solution when clarifying water on contact lights. It has been established that the treatment of clarified water with a modified aluminum sulfate coagulant solution during contact coagulation makes it possible to reduce the residual aluminum content in clarified water by an average of 50-60%, the quality of water purification in terms of bacteriological and hydrobiological indicators is much higher than when treating water with a conventional coagulant solution.

Shape-Controlled Self-Assembly of Light-Powered Microrobots into Ordered Microchains for Cells Transport and Water Remediation.

Nature presents the collective behavior of living organisms aiming to accomplish complex tasks, inspiring the development of cooperative micro/nanorobots. Herein, the spontaneous assembly of hematite-based microrobots with different shapes is presented. Autonomous motile light-driven hematite/Pt microrobots with cubic and walnut-like shapes are prepared by hydrothermal synthesis, followed by the deposition of a Pt layer to design Janus structures. Both microrobots show a fuel-free motion ability under light irradiation. Because of the asymmetric orientation of the magnetic dipole moment in the crystal, cubic hematite/Pt microrobots can self-assemble into ordered microchains, contrary to the random aggregation observed for walnut-like microrobots. The microchains exhibit different synchronized motions under light irradiation depending on the mutual orientation of the individual microrobots during the assembly, which allows them to accomplish multiple tasks, including capturing, picking up, and transporting microscale objects, such as yeast cells and suspended matter in water extracted from personal care products, as well as degrading polymeric materials. Such light-powered self-assembled microchains demonstrate an innovative cooperative behavior for small-scale multitasking artificial robotic systems, holding great potential toward cargo capture, transport, and delivery, and wastewater remediation.

Comparison of mineralogy and geochemistry of the suspended matter of waters from river runoff and snow cover of Lake Onega

Abstract. The data of mineralogy and geochemistry of suspended matter in water (filtered 0.45 microns), suspended solids (from filters of snow-fallen, river, lake waters) are compared from different parts of Lake Onego. We revealed the mineral composition of the suspended matter differs in the absolute contents of the suspended matter in the water, the ratio of the amount of organic matter in it, the presence or absence of aggregates of technogenic genesis and their quantity. The geochemistry of suspended matter from river s waters is highly similar to the geochemistry of suspended matter from water in various areas of Lake Onego, but significantly differs from the suspended matter of snow-covered waters.

Study of aluminium speciation in the coagulant composite of polyaluminium chloride-chitosan for the optimization of drinking water treatment

The control of aluminium speciation in coagulant composites is the appropriate approach to remove turbidity and natural organic matter from raw water effectively. This suspended matter in water affects its organoleptic quality and triggers problems by causing interference with the water treatment process. This study examined the behaviour of composite coagulants polyaluminium chloride-chitosan (PAC-CTS) with different aluminium speciation and polymer ratio to remove oxidizable matter and turbidity residing in surface waters. The fraction of basicity ratio (Al/OH) in the preparation of polyaluminium chloride (PAC) and chitosan (CTS) were simultaneously evaluated and optimized according to aluminium speciation by experimental design. The interaction between PAC and CTS was examined via Al-Ferron timed spectrophotometric approach, theoretical study and fourier transform infrared (FTIR) analysis. Ferron analyses reveal that basicity ratio and CTS fraction affect the distribution of aluminium forms (mononuclear Ala, medium polymeric Alb, colloidal, and high polymeric Alc) in PAC-CTS. The theoretical study showed that Al(OH)2+, Al13, and Al30 species are more reactive than aluminium hydroxide Al(OH)3 at different magnitudes and sites with chitosan. The FTIR analysis confirmed the existence of an interaction between PAC and CTS by revealing a new peak for Al-NH2 stretches. The coagulation performance study of composite coagulant PAC-CTS with different compositions showed that the increase of chitosan and the preponderance of Alb and Alc species compared to Ala are suitable for removing colloidal suspensions. Further, incorporation of PAC with high basicity (74.1%) in 16.3% of chitosan (PAC-CTS1) removed 99.51% of turbidity and 66.66% of oxidizable matter at AlCl3 concentration of 10 mg l−1. However, increasing the percentage of chitosan to 34.1% at the same basicity (74.1%) in the PAC-CTS4 compound was not beneficial for oxidizable matter removal. It was speculated that the improvement in coagulation performance could be achieved by considering the aluminum speciation and polymer content in the composite flocculant PAC-CTS. The present work could be a useful model for synthesizing and studying organometallic interactions in developing new composite coagulants to improve coagulation performance.

Evaluation of Total Nitrogen in Water via Airborne Hyperspectral Data: Potential of Fractional Order Discretization Algorithm and Discrete Wavelet Transform Analysis

Controlling and managing surface source pollution depends on the rapid monitoring of total nitrogen in water. However, the complex factors affecting water quality (plant shading and suspended matter in water) make direct estimation extremely challenging. Considering the spectral response mechanisms of emergent plants, we coupled discrete wavelet transform (DWT) and fractional order discretization (FOD) techniques with three machine learning models (random forest (RF), bagging algorithm (bagging), and eXtreme Gradient Boosting (XGBoost)) to mine this potential spectral information. A total of 567 models were developed, and airborne hyperspectral data processed with various DWT scales and FOD techniques were compared. The effective information in the hyperspectral reflectance data were better emphasized after DWT processing. After DWT processing the original spectrum (OR), its sensitivity to TN in water was maximally improved by 0.22, and the correlation between FOD and TN in water was optimally increased by 0.57. The transformed spectral information enhanced the TN model accuracy, especially for FOD after DWT. For RF, 82% of the model R2 values improved by 0.02~0.72 compared to the model using FOD spectra; 78.8% of the bagging values improved by 0.01~0.53 and 65.0% of the XGBoost values improved by 0.01~0.64. The XGBoost model with DWT coupled with grey relation analysis (GRA) yielded the best estimation accuracy, with the highest precision of R2 = 0.91 for L6. In conclusion, appropriately scaled DWT analysis can substantially improve the accuracy of extracting TN from UAV hyperspectral images. These outcomes may facilitate the further development of accurate water quality monitoring in sophisticated global waters from drone or satellite hyperspectral data.

Inversion and distribution of total suspended matter in water based on remote sensing images-A case study on Yuqiao Reservoir, China.

In this paper, Yuqiao Reservoir is taken as the research object. The total suspended matter (TSM) produced by the economic development in the upper reaches of the reservoir and its surrounding areas has brought great ecological harm to the safe operation of the reservoir. Satellite remote sensing technology provides a good way to obtain the temporal and spatial variation of TSM in the study area. Two field surveys were carried out in the Yuqiao Reservoir, a total of 44 sampling points collected in the two tests. The spectral data and concentration of TSM were obtained. We developed and validated a robust empirical model to estimate the concentration of TSM in the water of the Yuqiao Reservoir for the first time. The TSM distribution map of the Yuqiao Reservoir in 2013-2018 is retrieved based on Landsat 8 OLI images. This paper analyzes the spatial distribution characteristics of TSM concentration in the Yuqiao Reservoir for several years, as well as the interannual, seasonal, and monthly variation laws and development trends. The results show that the spatial distribution of TSM in Yuqiao Reservoir shows a decreasing trend from the periphery to the center; the interannual changes are mainly as follows: The annual change trend of TSM in Yuqiao Reservoir is not obvious; the seasonal changes are significant: the highest in summer (higher than 40mg/L), the second in autumn, and the lowest in spring and winter (lower than 15mg/L); and the monthly changes show regular fluctuations: In a year cycle, the concentration of TSM generally shows an inverted V-shaped trend; that is, TSM increases gradually from January to August and decreases gradually from August to December. The research results of this paper can be applied to other similar types of land water bodies, which will promote the wide application of Landsat 8 OLI images in the monitoring of TSM in lakes, rivers, and reservoirs in different regions across China, and provide data support for the scientific management of the safe operation of research areas. PRACTITIONER POINTS: The monitoring model of TSM in Yuqiao Reservoir was built for the first time. Temporal and spatial analysis of TSM concentration in Yuqiao Reservoir for the first time. The concentration of TSM is in Yuqiao Reservoir greatly affected by wind speed and precipitation.

The study of the suitability for use in agriculture of sludge and hydrochemical indicators of water in the reservoirs of the fish farm LLC “Albashi”

The study of suitability for the use in agriculture of sludge deposits and hydrochemical indices of water bodies of fish-growing enterprise of LLC “Albashi” were carried out. It is an enterprise engaged in breeding and growing pond fish and sturgeon in pools and gardens, crayfish, growing aquapon greens. Fresh water bodies of reservoir type LLC “Albashi” contain a large number of bottom deposits. The layer of sludge deposits on the bottom in places reaches the power of 2-5 meters, and the underground power is difficult. Bottom sediments were taken from a depth of 1.0-1.2 m from the surface. The hydrochemical regime of the studied water bodies fully corresponds to the cultivation of aquaculture objects and hydroponic plants. Sufficient suspended matter in water (8.2 mg/dm3). The complete absence of dichlorodiphenyl trichloroethane, its metabolites and pesticides characterizes the products produced as environmentally safe. Consequently, bottom sediment site under study can be considered suitable for agricultural production.

Restrained fall velocity of suspended solids particles sedimentation in still water

The deposition rate is sufficiently studied in the case of single particles or in conditions of low concentrations of suspended matter, in which the precipitating particles do not affect each other. In the article, the method of calculation of the rate of the constrained deposition is offered, comparative calculations of the rate of the free and constrained deposition of particles are executed, the settlement results reflecting essential difference of the speed of the constrained and free deposition of particles are presented. The factors influencing the rate of confined deposition, among which the main one is the concentration of suspended matter in water, are considered. The experimental data confirming the reduction of speed of the constrained deposition of more than 3 times in a five-fold increase in the concentration of suspended solids is given. The dependence of the strained deposition rate of particles on the concentration of the suspension is obtained.

Low Cost Chitosan Biopolymer for Environmental Use Made from Abundant Shrimp Wastes

Chitosan, an important biopolymer with many uses, is made by deacetylation of chitin. Classical hydrolysis at high temperatures (above 100 °C) in 50 % concentrated sodium hydroxide during several hours produces chitosan, a poly-beta-glucosamine. This chemical deacetylation step is often performed under pressure in boiling ethyleneglycol and tends to degrade polymer chain length, thus the interesting polymer properties. It is convenient to search for a more economical production pathway in order to make chitosan available for environmental applications, such as use in water suspended matter flocculation. Chitin was extracted from the exoskeletons of shrimps and its deacetylation kinetics was followed for 35 days at 20 and 35 °C. The results obtained using different techniques (conductivity, viscometry, 13C NMR and thermogravimetry) showed that the deacetylation degree of chitin increased with the incubation time reaching 99 and 88 % at 35 and 20 °C, respectively, after 35 days. Moreover, during the incubation time, the molecular weight of chitosan showed moderate decrease compared to deacetylated chitin at high temperature. Clarification or urban waste water with chitosan biopolymer demonstrated good results at 1.5 mg/L concentrations.

Distribution and composition of suspended matter in water and snow cover in Kaliningrad Bay

Field data, collected by the authors during winter expedition studies in Kaliningrad Bay, are analyzed. Notwithstanding the presence of ice cover, considerable advective processes are shown to be taking place in the bay. Seawater enters the bay, spreading in the bottom horizon all over the water area. Suspended sediment concentration in under-ice period is on the average three times less than that in the ice-free period. The space and time variations of its quantitative and qualitative composition under ice are mostly governed by two factors—the effect of the sea and river runoff. The values of vertical fluxed of eolian material to the bay surface in winter vary from 0.5 to 2.9 with the average of 1.7 mg m–2 day–1.

The Effects of Meteorological Factors Anomalies on Oceanic Coral Reef Systems in the Northwestern South China Sea

Climate warming, variation of East Asian atmospheric system have affected the Chinese offshore environment through the air-sea interaction, the coastal waters of South China Sea had been influenced, leading a corresponding impact on the coral reef growth. This paper reports on coral coverage and dominant coral species changes in Xu wen National Coral Reef Nature Reserve, examines their relationship with meteorological factors anomalies recorded by satellite. The study reveals that: compared to the period from 1979 to 2003, the temperature of surface coastal water dropped significantly in South China Sea in 2004-2008, the divergence of low layer of atmosphere over it strengthened, produced a zonal westerly anomaly field, which had an opposite direction to the local northeastern trade wind. The increasing of suspended matter in water, the decreasing of down welling in northwestern South China Sea, made the water quality deteriorating, water transparency decreased significantly, coral reef survival environment worsened, which would cause adverse effects on coral reef building capacity in the Reserve. Continued monitoring efforts are necessary to further assess the relationship between coral building capacity and in situ meteorological factors anomalies and improve the use of the dataset in future regional degradation predictions.

Seasonal dynamics of suspended matter in waters of Lake Khanka

Outline maps of the distribution of suspended mineral matter in the waters of Lake Khanka are constructed from the summer, spring, autumn, and winter observation results. The analysis allows distinguishing seasonal variations in the distribution of suspended mineral matter over the lake water area and shows that the lake ecosystem functions under conditions of an uninterrupted annual cycle of suspended matter concentration.

Forms of some metals in the suspended sediments of the Northern Dvina River and their seasonal variations

The results of the analysis of samples of the Northern Dvina River’s suspended particulate matter obtained by the sedimentation method from large water volumes in the periods of the spring high water and summer low water are presented. By the method of sequential leaching using different reagents, four fractions have been separated: the F1 is the sorbed complex and carbonates, the F2 is the amorphous hydroxides of Fe and Mn, the F3 is the form connected with the organic matter, and the F4 is the residual or silicate-detrital (inert) form. The data have shown that all ten elements determined were grouped with respect to the ratio of the distinguished forms: F4 is the predominant form for Al and Fe (73–88% of all the forms; however, the summer sample contains only 38% of this form of iron, and F2 is the predominant form for this period with 46.6%). As to Mn, the F1, F2, and F4 are nearly equally distributed in the spring high water samples, and only the F3 form is less important (5.4%). In the summer sample, the manganese sorbed complex is predominant (53.5%); for Cu, Ni, Cr, and Co, the inert F4 form is predominant (60–70%) in the sample of the spring suspended matter. The summer low water suspended matter has a lower F4 contribution (25–45%); for Zn, Pb, and Cd, the equal distribution of the forms in the spring samples is typical, while the summer suspended matter differs by the F2 form’s predominance (53–61% for Zn and Pb). The main conclusion from the acquired data is that the geochemical mobility of all the studied elements, except for cadmium, in the summer low water suspended matter is higher than in the spring suspended matter. The more intensive biogeochemical processes in August, the high level of organic matter, and the higher contribution of phytoplankton lead to the intensification of the metals’ geochemical activity in the Northern Dvina suspended matter in the end of the summer compared to the spring high water period when the physical processes are predominant over the biogeochemical ones due to the high speeds of the freshened waters flow.

Protection of non-human biota against radiation in freshwater—Effect of time dependence in tiered exposure assessment

The ERICA's European framework that have been proposed to assess the exposure of biota to radionuclides is based on tiered approach: the Tier 1 assessment is based on equilibrium assumptions (constant radioactive releases over time, equilibrium at the interfaces water-suspended matter and water-biota); the Tier 2 assessment allows to use time-dependent and site-specific data to perform a more precise evaluation. The objective of this paper was to compare these two tiers in the context of routine releases from nuclear power plants in freshwater ecosystem. The Loire River where 14 nuclear power plants (NPPs) operate was chosen as a case study and the transport of 60Co in the river, its partition between water and suspended particles and its bioaccumulation was calculated under equilibrium and time-dependent assumptions respectively. Using this case study allowed to quantify the overpredictions linked to conservatisms assumed in Tier 1. Recommendations were identified on when a Tier 2 approach is actually needed.

フィルター法を用いた蛍光Ｘ線分析法による水中懸濁物質の化学分析の評価

フィルター法を用いた蛍光Ｘ線分析法による水中懸濁物質の化学分析の評価

Improving chlorine disinfection of wastewater by ultrasound application

The presence of soluble organic material as well as high concentrations of suspended matter in waters and wastewaters affect the efficiency when chlorine is used as disinfection agent. The objective of our work is to explore to which extend ultrasonic treatment can facilitate wastewater disinfection with chlorine in order to bring down doses of ecologically questionable chlorine and to shorten contact times. Sewage treatment plant (STP) effluents with different concentrations of suspended solids are exposed to sonication in combination with chlorine dosage. We observed that enhancement of chlorine efficiency is better for samples with higher concentrations of suspended matter. For samples with a TSS concentration of 50 mg/L chlorination efficiency (2 mg/L) can be doubled from 0.7 to 1.4 log when treated simultaneously with 20 kHz ultrasound for 5 minutes, i.e. levels of indicator organisms can be brought down to numbers that conventionally require far higher doses of chemical disinfectants. As subsequent sonication/chlorination does not have the same significant effect as simultaneous application of these two means, ultrasound does not just have a declumping effect; it seems that ultrasound application provokes a better chlorine dispersion in the aqueous media which improves the fast chemical and bactericidal reaction.

Copper, lead and zinc distribution in soils and sediments of the south-western coast of the río de la plata estuary

The compositional study of suspended matter in water from rivers of different latitudes and climates has revealed that the fine fraction reflects both substrate lithology from source areas or topsoil composition along the course. Metal distribution patterns are also strongly related to the clay mineral fate in fluvial aquatic systems. For the particular case of the coastal area of the Río de la Plata estuary in South America, previous studies have, on the one hand, focused on the analysis of distribution patterns of heavy metals in bottom river sediments and, on the other hand, on the assessment of metal contents in topsoils. The present study was conducted to evaluate the Cu, Pb and Zn distribution in soils and sediments from four drainage basins crossing two differentiated geomorphologic units composed of unconsolidated materials and to understand the metal behaviour. Data used included the existent, self-produced soil and sediment data sets (grain size, organic matter and Cu, Pb and Zn contents from 124 samples). Analyses were performed by using standardised methods: grain size analysis by sieving and settling; organic matter content based on the reduction of dichromate ion followed by titration; metal content by atomic absorption spectrophotometry following acid digestion. Results and Discussion. The average (% w/w) clay and organic matter content were 45.9 ± 17.1 and 1.5 ± 1.7 for sediments and 32.0 ± 19.8, and 7.5 ± 7.6 for soils, respectively. The raw mean metal concentrations (mg-kg-1 dry weight) for sediments and soils were: Cu: 28.02 ± 27.28, 32.08 ± 21.64; Pb: 32.08 ± 46.94, 68.44 ± 69.25 and Zn: 83.09 ± 150.33, 118.22 ± 74.20, respectively. A good correlation for each clay-normalised metal concentration was found between soil and sediments using regression analysis considering average data for each basin sampling site (r > 0.89, p < 0.05). A comparison between metal concentration levels taking into account geomorphologic units by a t independent sample test showed significant differences for the normalised soil-sediment metal data (p < 0.001), responding to differences in grain size, clay mineralogy, organic matter and neoformed Fe-Mn oxide composition. A clear parenthood between the topsoils and the bottom sediments in the study area was found. The Argiudolls from the inner zone are frequently affected by rainwater erosion, which washes the fine materials with sorbed metals and carries them to the streams. These watercourses reach the flat coastal plain, where soil flooding and bottom sediment depositional processes predominate. Here, both soils and bottom sediments are enriched in clay, organic matter and metals. The topography and lithology, under the environmental conditions of a temperate and humid climate control the fate of metals within these small basins. The influence of the physical media on the distribution and fate of pollutants should not be minimised in the understanding of the governing processes from natural systems.

A New Power-Law Relation For The Vertical Distribution of Suspended Matter

Generally, the vertical distribution of suspendedmatter is described by a simplepower-law relation in which it is assumed that thefriction velocity is constant withheight. This is a simplification of the actual mechanismof turbulent transport, sinceturbulence will most likely be reduced in the presenceof suspended particles for avariety of reasons. Here we investigate analytically,by assuming a constant shearstress with height, how the increased density of thetwo-phase mixture reduces thefriction velocity. This reduces the upward turbulentflux of particles, which tends todecrease the drift density compared to a situation inwhich changes in friction velocityare neglected. A new power-law relation is derived,which in snowdrift predicts amaximum reduction in drift density of 25% (and 40%for Martian dust) over thestandard power-law relation. In other geophysicaltwo-phase flows, such as suspendedmatter in water, the effects are shown to be negligiblebecause of the small ratio of driftdensity and medium density. Generally, this and otherinteractions between the particlesand the flow should be taken into account to betterunderstand the vertical profile ofsuspended matter in geophysical two-phase flows.

Wind-induced long term increase and short term fluctuations of shallow water suspended matter and nutrient concentrations, Ringkøbing Fjord, Denmark

Abstract The terrestrial supply of nutrients to the shallow lagoon Ringkøbing Fjord has shown a significant downward tendency for phosphorus during the past 10 years. In spite of a decreasing supply, there is at the same time an increase in nutrient concentrations, especially for P, but also for the suspended matter content in the fjord- Analyses af wind data from nearby lighthouses show that the frequency of strong winds from the SW (equal to the longest fetch) has gone up in the same period of time and that both the nutrients and suspended matter concentrations in the water column are well correlated with available wind energy and hence, with the possibilities for wave-induced resuspension of material from the fjord bottom. During a 6 month period, daily fluctuations of concentrations in the water column were measured in samples taken by automatic samplers at four stations with different exposures. Due to wave induced resuspension, the day to day variations were between 2-895 mg DW l-1 of suspended matter, 0.2.-24.5 mg l-1 of organic matter, 0.1-1.1 mg l-1 of Total-N, and 0.01-0.18 mg l-1 of Total-P. Fortnightly measurements of erosion rates at station bottoms showed that as much as 3 cm of the sediment surface were resuspended during periods of hard wind conditions. The resuspended particles had mode sizes of 30-40µ, i.e. high sinking rates are assumed. The concentrations af suspended matter observed in the water column, however, were not below 40 mg DW l-1 in 50% og the time, leading to a marked effect on light penetration in water. The Secchi-depth is on average reduced to 0.6 m in summer and 0.7 m in winter.