Suspended Organic Matter Research Articles

While legal regulations require treated wastewater to be tested based only on its physicochemical parameters, surface water assessment also has to include biological indicators. However, neither approach provides a complete picture of water quality due to lack of ecotoxicological information. Therefore, the aim of the study was to perform an ecotoxicological evaluation of treated wastewater and river water in the catchment scale using a battery of biotests. In the period between June 2017 and July 2018, six sets of treated wastewater samples were taken from 17 municipal wastewater treatment plants (WWTPs) of different sizes (small: < 2,000 people equivalent - p.e.; medium size: 2,000–9,999 p.e.; large: 15,000–99,999 p.e.), as well as river water samples from seven sites along the 342 km Pilica River in central Poland. Physical and chemical analysis were performed of total nitrogen (TN), total phosphorus (TP), biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS), as well as organic suspended matter (OSM), ion content (fluorides, nitrates, ammonium, potassium and sulphate), and pH, conductivity and redox potential (RP). Ecotoxicity assessment was performed using a battery of biotests comprising the producer Pseudokirchneriella subcapitata (chronic toxicity biotest), consumer Thamnocephalus platyurus (acute toxicity biotest) and decomposer Tetrahymena thermophila (chronic toxicity biotest). It was found that in small WWTPs, the recommended levels of TN, TP, BOD, COD and TSS were often exceeded. Also, the highest mean toxicity hazard in the ecotoxicological biotests was observed for samples from small WWTPs. No clear dependence was found between any of the studied physicochemical parameters of the water and the ecotoxicity of samples: however, a correlation was observed between growth inhibition of P. subcapitata and TN and NH4+ concentration (r = 0.43 and r = 0.48, respectively). Also, the mortality of T. platyurus was correlated with NH4+(r = 0.72), TN (r = 0.64), BOD (r = 0.52), TSS (r = 0.44) and OSM (r = 0.46). The most sensitive organism in the applied battery of biotests was the alga P. subcapitata (producer), with a 90% toxic response for WWTP samples and 100% for river samples. T. platyurus (consumer) demonstrated a 56% toxic response for WWTP samples and no toxicity (0%) for river samples. In turn, T. thermophila demonstrated a 25% toxic response for WWTP samples and 33% for river samples. The addition of an ecotoxicological evaluation (battery of biotests) to the physicochemical monitoring of treated wastewater and river water delivered new information about the biological impact on organisms related to their different sensitivity. Additionally, the small WWTPs turned out to be the highest source of hazard.

Abstract Food partitioning among coexisting species is often considered advantageous to minimize niche overlap and avoid inter-specific competition. Congeneric fish species such as the mullets Mugil curema and Mugil liza, which co-occur across marine and estuarine habitats, are good models to evaluate resource use and niche overlap or partitioning. We used stomach contents (SCA) and stable isotope analysis (SIA) to assess potential trophic shifts and changes in niche overlap associated with the mullets transitioning from marine to estuarine habitats. SIA included different fractions of organic matter in suspension and in the sediment to estimate the contribution of micro, nano and pico-organisms to the mullets’ diets. We hypothesized higher resource partitioning in the less resource-diverse system (marine surf-zone) than in the more diverse one (estuary). SCA showed diet differences between M. curema and M. liza according to the habitat. They showed distinct diets in the marine area (P &lt; 0.001), but similar diets in the estuary (P = 0.226). A lower niche breadth was observed for both species in the marine area (M. curema = 0.03, M. liza = 0.06) compared with the estuary (M. curema = 0.14, M. liza = 0.16). Isotopic niches of both species were higher in the estuary (64.7%) compared with the marine area (0.7%). These findings corroborated our hypothesis of higher food partitioning in the marine surf-zone. We also demonstrated using SIA the shift from planktonic to benthic feeding following the recruitment of the mullets from the surf-zone into the estuary.

Simple and suitable treatment of swine slurry from small farms is paramount especially in sensitive areas. This paper evaluates the viability of an innovative nature-based technology hybrid system (a Vertical Flow Constructed Wetland followed by a Horizontal Flow Constructed Wetland both planted with reeds – Phragmites australis) to treat swine slurry for further land application or discharge in water bodies with reduced nitrogen impact. Physicochemical parameters, bacterial indicators, surface deposits and biomass inside the filters were monitored. The hybrid configuration offered a dual function for simultaneous solid-liquid separation and biological treatment. Removal of organic matter and suspended solids was very high (&amp;gt;80% for SS and &amp;gt;75% for COD and BOD5) while the overall nitrogen load removal was 65%, due to the combined nitrification/denitrification processes, thus effectively reducing swine slurry nitrogen content. The influence of temperature and design and operational parameters on the treatment efficiency and the hydraulic behavior were also studied. The vertical constructed wetland achieved good hydraulic performance with no clogging problems, despite high pollutant loads. Some of the pollutants were retained and mineralized in the surface deposit layer, increasing around 20 cm each year. This organic biosolid layer improved filtration efficiency. The high ammonia contents interfered with the growth of Phragmites australis, while the high concentration of suspended solids and organic matter determine the operation and design to be implemented.

Land-use change, such as agricultural expansion and intensification, and urbanisation, affects river ecosystem health and threatens riverine biological communities in a multifactorial and interactive way. In this study, we compiled the results of several studies carried out in a 5th-order tropical river, the Rio das Mortes in the upper Rio Grande basin (Southeast Brazil). We analysed if a combination of different environmental indicators, such as river water quality, sediment structure, habitat structural integrity, biochemistry of suspended organic matter, and the composition and distribution of the benthic invertebrate community, provides a complementary and more complete assessment of land-use impacts from headwaters to the river mouth than single indicators. Water quality exhibited longitudinal changes along the studied river, especially during the dry season, corresponding to the urbanisation pattern in the river catchment with considerable urbanisation already in the upper catchment, and several urban centres along the river's course. The predominance of saturated fatty acids and bacterial fatty acids in the river water's suspended organic matter at urbanised river segments showed that the biochemistry of suspended organic matter, an important resource for the river's biological community, was a sensitive indicator of catchment urbanisation. In contrast, river sediment structure and habitat integrity showed local impacts, primarily in mid-catchment urbanised river segments, with notable positive effects of local conservation efforts and natural differences in sediment structure. Chironomidae and Oligochaeta were the dominant groups in the river's macroinvertebrate community. Their spatial distribution was mainly determined by sediment structure and river habitat integrity, and thereby, by local impacts on river structure. We argue that integrated assessment approaches rarely applied to larger tropical rivers, combining local structural, habitat and community characteristics with large-scale land use and water quality patterns, are important to understand and manage land-use stress in these systems.

The manifestation of severe acute respiratory syndrome coronavirus 2 (SARS- CoV-2) in water and wastewater has newly been revealed. The stools and masks of the patients diagnosed with coronavirus disease (COVID-19) were viewed as the key way of CoV diffusion into aquatic medium. Most CoV kinds that attack human (likely for SARS-CoV-2) are frequently demobilized quickly in water (the endurance of human CoV 229E in water being 7 days at 23°C). Nevertheless, the endurance time of CoV in water strongly follows temperature, characteristics of water, concentration of suspended solids and organic matter, solution pH, and dose of disinfectant injected. The present disinfection technique of potable water can efficiently demobilize most of the bacterial and viral communities existing in water, particularly SARS-CoV-2 (more vulnerable to killing agent such as free chlorine). Scientists affirmed that SARS-CoV-2 RNA was observed in inflow wastewater and not found in outflow one. Even if the occurrence of SARS-CoV-2 in water influents has been affirmed, a fundamental interrogation is whether it could remain alive or contaminate following the disinfection method of potable water. Until now, only one study asserted that the infectivity of SARS-CoV-2 in water for persons was null founded on the absence of cytopathic effect in infectivity tests. Thus, more researches must be dedicated to the survival of SARS-CoV-2 in water and wastewater below various working circumstances (temperature and water matrix) and whether the diffusion from COVID-19-infected water to human is an emerging anxiety.

Based on the data of integrated observations, the variability of phytoplankton, the amount of suspended organic matter and zooplankton of the pelagic zone of the Kerch Strait and the pre-strait zone of the Black Sea is considered. The algal flora of the entire Black Sea, the Kerch Strait and the pre-strait is characterized by the predominance of diatoms over pyridineas (pyrrophytes or dinoflagellates). The study of the species range, number and biomass of the phytoplankton community during several periods of the year showed that its dynamics is largely dependent on seasonal weather changes (climate). In the process of phytoplankton development, several phases of autogenic succession were revealed. It is expressed in a sequential change in phytoplankton forms, changes in its abundance and biomass typical of the eastern shelf of the Black Sea. The zooplankton community of the Kerch Strait is represented by micro-, meso- and macro- zooplankton typical of the Black Sea. Microzooplankton is represented by zooflagellates and protozoa, as well as by early larval stages of planktonic crustaceans, apendicularia and mollusks. Its total biomass averages about 80 mg/m3.The above analysis of the collected material allows us to conclude that the distribution of suspended matter and larvae is related primarily to the peculiarities of water circulation in the strait. In the case of low concentrations of larvae, the dynamic factor can be decisive in the process of sedimentation intensity. The amounts of suspended matter can reach 20 mg/m3, which is 2-3 times higher than on average for the Black Sea. It further demonstrates the high productivity of waters and the prospects of the latter to be the area for commercial growing of mussels.

Sedimentation rates of nutrients and particulate material in pond mariculture of shrimp (Litopenaeus vannamei) carried out with different management strategies

Simulation and optimization of a lamella settler for cattle feedlot wastewater treatment and nutrients recovery. Experimental validation in the field

Surface waters are generally turbid because they contain suspended matter, organic matter, chemical and physical or even biological elements that make these waters unfit for drip irrigation. The almond powder of Moringa oleifera that was used in the study was dried in an oven for one month at temperatures of 25, 40 and 50°C and used to treat the water of Kongou Gorou Zarmagandey pond so it is suitable for localized irrigation. The purpose of this study was to evaluate the physico-bacteriological quality of the waters of this pond. The parameters studied are Escherichia. coli, faecal Streptococci, total germs and sulphito-reducers, organic matter, total residues and the color of treated water. After treatment of water with 100 mg/Lp Moringa oleifera seed powders dried at the respective temperatures of 25, 40 and 50°C, the supernatants were removed and analyzed. The results of this analysis show an increase in organic matter of 52.59, 55.84 and 57.14%; a slight reduction in total residues of 0.7%, 4.3% and 2.5% at the respective temperatures of 50, 40 and 25°C; an abatement of Escherichia. Coli is total (100% for all temperatures). For Streptococci, a reduction of 99.24% was observed for the dose at 25°C and 98.48% for those at 40 and 50°C. For Sulfo-reducing agents, the efficacy of the treatments is therefore total, 100% for doses of 100 mg. 1 to 25 and 40°C and about 99.99% for that at 50°C. Finally, in terms of color, there was a drop of 97.62%; 97.858% and 98.167% at the respective temperatures of 50°C, 25°C and 40°C. The analysis of the water in the study area shows that the latter is in line with the FAO guidelines on the physico-bacteriological aspects of irrigation water in general and that of drip irrigation in particular.

Abstract. Zooplankton aggregation, hydrographic and remote sensing data were employed to relate the spatial dynamics of neustonic communities with chlorophyll a (Chl a) and suspended organic matter (SOM) at a spatial mesoscale (10 to 1000 km) in the southern Chilean fjords system along Magellan Strait, Chile (CIMAR 16: October/November 2010 and CIMAR 25; September/October 2019) in order to identify oceanographic process producing aggregation of neuston. Preliminary evidence of CIMAR 25 shows significant concentrations of Chl a and SOM around Dawson Island (DI), Magellan Strait. During CIMAR 16 important aggregation of specific neustonic taxa (copepodites of Microsetella rosea, larvae of the polychaete Polygordius sp and cyphonautes of the bryozoan Membranipora isabelleana) was observed around DI, Magellan Strait. Satelital images in the area of CIMAR 16 provide evidence of important aggregation of chlorophyll a/SOM around DI. CIMAR Cimar 25 showed that the Chl a and SOM aggregation around DI is recurrent and could to explain the high concentration of neuston around this island to spite of mesotrophic conditions. Remote sensing in this study area provides a tool to understanding oceanographic and topographic factors that potentially regulate the abundance and spatial distribution of surface zooplankton to spatial meso-scale along Magellan Strait.

• Petroleum-originated pollutants and their effective mitigation is reviewed. • The persistence of toxic substances causes threats to the living ecosystems. • Effective remediation of contaminated environment is of supreme interest. • Hybrid materials with smart surfaces are effective to remediate hydrocarbons. The generation and controlled or uncontrolled release of hydrocarbon-contaminated industrial wastewater effluents to water matrices are a major environmental concern. The contaminated water comes to surface in the form of stable emulsions, which sometimes require different techniques to mitigate or separate effectively. Both the crude emulsions and hydrocarbon-contaminated wastewater effluents contain suspended solids, oil/grease, organic matter, toxic elements, salts, and recalcitrant chemicals. Suitable treatment of crude oil emulsions has been one of the most important challenges due to the complex nature and the substantial amount of generated waste. Moreover, the recovery of oil from waste will help meet the increasing demand for oil and its derivatives. In this context, functional nanostructured materials with smart surfaces and switchable wettability properties have gained increasing attention because of their excellent performance in the separation of oil–water emulsions. Recent improvements in the design, composition, morphology, and fine-tuning of polymeric nanostructured materials have resulted in enhanced demulsification functionalities. Herein, we reviewed the environmental impacts of crude oil emulsions and hydrocarbon-contaminated wastewater effluents. Their effective treatments by smart polymeric nanostructured materials with wettability properties have been stated with suitable examples. The fundamental mechanisms underpinning the efficient separation of oil–water emulsions are discussed with suitable examples along with the future perspectives of smart materials.

Designing an economical slow sand filter for households to improve water quality parameters

Roughing filters are types of porous media filter used in pretreatment systems where the raw water contains a large amount of suspended particles (SPs) and organic matter. Mesh tube filtration (MTF) media are roughing-filter media composed of low-density polyethylene used for SP removal during wastewater treatment. In this study, we present an improved MTF design—a porous filter bed (PFB), which exhibits superior SP removal performance compared to conventional MTF media. We then compare the applicability of MTF and PFB to both the primary pretreatment process for seawater desalination and the water reuse process. In bench-scale SP removal experiments, PFB shows removal rates of 46.7%, 68.0%, 67.6%, and 68.4% at hydraulic retention times of 15, 20, 30, and 60 min, respectively, which are better than those of MTF. The specific energy consumption (SEC) of batch dissolved air flotation (DAF) was known to range from 0.035 to 0.047 kWh/m3, whereas the SEC calculated for pilot-scale MTF and PFB is 0.027 kWh/m3 and minimum energy for influent supply, respectively. This suggests that PFB can compete with DAF as a primary pretreatment process. MTF predominantly removes SPs by sedimentation, whereas SP removal in PFB typically occurs via deposition of SPs on the mesh tube media.

SARS-CoV-2 coronavirus in water and wastewater: A critical review about presence and concern

Cell membrane intact polar lipids (IPLs) are chemotaxonomic biomarkers whose abundances and distributions in water column environments reflect the living biomass of in situ microbial communities, and can be used to determine the relative contribution of distinct functional and phylogenetic groups to water column carbon stocks. The diversity of IPLs in marine environments is however vast, while our knowledge of their biological origins remains limited. Here, we study the distribution of IPLs in size-fractionated suspended organic matter from the oxygen minimum zone (OMZ) of the eastern tropical South Pacific (ETSP) off northern Chile. Canonical correspondence analyses of total IPL abundances and water column physiochemistry demonstrate distinct distributions of microbial sources associated with different geochemical regions in the water column (chlorophyll maximum, upper chemocline, lower chemocline, upper OMZ, core OMZ, and mesopelagic region). Furthermore, the distribution of IPLs in free-living (0.3–2.7 µm) and particle-attached (2.7–53 µm) suspended organic matter differs, suggesting distinct biological sources in each size fraction. While some parallels exist, the diversity and distribution of IPLs in the OMZ system of the ETSP off northern Chile exhibited some unique features compared to other OMZ systems; for instance, we observed a significantly lower contribution of betaine lipids from phytoplanktonic sources, possibly reflecting a physiological response to severe N-limitation in this area. The overall IPL abundance in the two size fractions also indicates a dominance of free-living biomass in the OMZ and mesopelagic regions, suggesting that these areas of the water column could provide additional sources of submicron organic carbon to deeper waters. This study improves the utility of IPLs as chemotaxonomic biomarkers by providing insight into the contrasting distributions of microbial biomass from different life modes (free-living and particle-attached). Our results suggest that microbial production in low oxygen environments may be more important to total water column carbon stocks than previously thought.

Practical applications of sensor-based methodologies for monitoring peracetic acid (PAA) as a disinfectant of fresh produce wash water

Transport analysis of particulate matter in media-saturated mesh tube filter for the desalination primary pretreatment process

Nejayote is the residual water from the nixtamalization process characterized by an alkaline pH (pH &gt; 10) as well as high concentrations of dissolved and suspendedorganic matter (COD &gt; 10 200 mg/L). As for the above mentioned, nejayote is considered within the more pollutants liquid effluents discharged into different water bodies. In this work, the effectiveness of sodium alginate and chitosan to reduce nejayote pollutants was tested. The application of alginate involved adsorption and gelation, which trapped suspended and dissolved material, and the use of chitosan implied an adsorption-precipitation phenomena. These polymers were used separately and sequentially. In the independent treatments, the alginate was more efficient than the chitosan, obtaining a COD removal of 61.43 ± 0.24 % and of 59.74 ± 0.36 % respectively. In sequential treatments, the removal efficiency of COD with alginate-chitosan was higher (70.19 ± 0.85 %) than that of the chitosan-alginate treatment (67.21 ± 0.24 %). On the other hand, the reduction in the amount of total solids allows that the effluent, after the processing, is within the maximum permissible limit established by the official Mexican standards NOM-002-SEMARNAT-1996 and NOM-001-SEMARNAT-1996.,This permits its discharge to urban or municipal sewerage systems and it can even be used for agricultural irrigation. The use of these biodegradable polymers is a viable option that has the potential to scale at the industrial level, contributing to the purification of discharges from the nixtamalization industry and to the benefit of the environment.

Measurements for determining the effect of chemically enhanced primary treatment (CEPT) on the efficiency of pollutant removal from wastewater were carried out using conventional inorganic coagulants PIX113 with polymer A110 (Kemipol, Police, Poland) and unconventional cationic organic coagulants Cofloc (Attana, Coalville, UK) C29510 (Kemipol, Police, Poland) and Sedifloc 575 (3F Chimica, Sandrigo, Italy). The average removal efficiency in the 2-h sedimentation process was 46%, 34%, 8%, 12% for the total suspended solids, organic matter (COD), total nitrogen, and total phosphorus, respectively. The use of organic coagulants contributed to 14–81% increase of pollutant removal efficiency. Substantial discrepancies in biological nutrient removal processes were not discovered in two-phase (anaerobic-anoxic) experiments without and with the addition of the organic coagulants. The increase in organic matter removal efficiency as a result of the CEPT process may contribute to a 65–80% increase in biogas production. The conducted research confirms the possibility of using organic coagulants in the primary precipitation process in wastewater treatment plants (WWTPs) in accordance with the principles of maximum energy recovery, thereby promoting renewable energy sources. Additionally, organic coagulants, as opposed to inorganic ones, do not cause a significant increase of chloride and sulfate ion concentrations, which facilitates the use of treated wastewater in the water reuse systems, such as irrigation of agricultural crops.

Abstract We developed a technique for reconstructing annual gravel yields and generated a 55‐year record of gravel transport for the North Fork catchment of the Caspar Creek Experimental Watersheds in Northern California. The technique relies on field data collection including annual surveys of weir pond volumes and suspended sediment measurements, as well as an accounting for settling of suspended sediment and organic matter in the pond. We compared these annual yields to gravel yields predicted by the Wilcock two‐fraction bed load transport model, which we calibrated from measured values at Caspar Creek. We considered three velocity‐discharge relationships and found that values of hydraulic variables measured during storms produced the best fit between reconstructed and predicted annual gravel yields when years with large disturbances were excluded. We also compared predicted gravel transport rates to bed load transport rates measured from 1988 to 1995 with bed load pit samplers. We found that the calibrated model predictions agreed well with the field‐measured bed load transport rates. To investigate the role of supply and storage on gravel transport, we compared the reconstructed gravel yields to predicted gravel yields and found that increased occurrence of landslides and headcut erosion in the 1990s and early 2000s did not lead to an increase in gravel yields. Instead, input of large downed wood in the 1990s created storage space and decreased bed load delivery to the weir pond.