Effects Of Sewage Discharge Research Articles

Effects and driving factors of domestic sewage from different sources on nitrous oxide emissions in a bog

Abstract Direct sewage discharge may enhance soil nitrous oxide (N2O) emissions, worsening the greenhouse effect. However, the effects of sewage discharge into bogs on N2O flux, drivers and influencing mechanisms remain unclear. Additionally, investigating the impact of reclaimed water on N2O flux is important for bog replenishment and water shortage alleviation. This study simulated sewage from different sources into a bog and analyzed N2O fluxes, soil (organic carbon, total nitrogen, ammonium nitrogen, nitrate nitrogen, total phosphorus, available phosphorus, pH and electrical conductivity), plant (species richness and biomass) and microorganisms (ammonia-oxidizing archaea, napA, nirS, nirK and nosZ genes). Results showed that the reclaimed water did not significantly change N2O flux, while 50% tap water mixed with 50% domestic sewage and domestic sewage significantly increased the N2O flux. Among soil factors, available nitrogen and pH were key in influencing N2O flux. Among plant parameters, species richness was the primary factor affecting N2O flux. Nitrogen transformation functional genes contributed the most to the increase in the N2O fluxes, with an increase in domestic sewage input leading to a higher abundance of these genes and subsequent N2O emissions. Therefore, domestic sewage should be considered, as it significantly increases N2O emissions by affecting the soil, plants and microorganisms, thereby increasing the global warming potential. This study’s findings suggest that using treated reclaimed water for bog replenishment could be an environmentally friendly approach to wetland management.

Land-derived wastewater facilitates antibiotic resistance contamination in marine sediment of semi-closed bay: A case study in Jiaozhou Bay, China

The emergence of antibiotic resistance is a severe threat to public health. There are few studies on the effects of sewage discharge on antibiotics and antibiotic resistance genes (ARGs) contamination in Jiaozhou Bay sediment. Herein, a total of 281 ARG subtypes, 10 mobile genetic elements (MGEs), 10 antibiotics and bacterial communities in marine sediments from Jiaozhou Bay were characterized. Similar bacterial community structures and ARG profiles were identified between the various sampling sites inside the bay, which were both dominated by multidrug and (fluoro)quinolone resistance genes and harbored lower relative abundances of ARGs than those in the sampling sites near the bay exit. Compared with antibiotics and MGEs, bacterial community composition was a more important driver of ARG diversity and geographic distribution. The abundance of pathogens carrying genetic information increased dramatically in southern Jiaozhou Bay is affected by sewage discharge, which indicating that wastewater discharge facilitated ARG contamination of marine sediments. This study highlights the risk of disseminating antibiotic resistance-influencing factors from treated wastewater discharge into marine environment there is an urgent need to optimize or improve wastewater treatment processes to enhance the removal of antibiotics and ARGs. This study has necessary implications for filling the gap in information on antibiotic resistance in Jiaozhou Bay and developing future pollution regulation and control measures.

The diversity of comammox bacteria and the effect of sewage discharge on their abundance in eutrophic lake sediments

Complete ammonia oxidation (comammox) bacteria can independently oxidize ammonia to nitrate, and their discovery has changed the long-term understanding of nitrification. Comammox bacteria have been found in a variety of natural environments, but there is still a lack of understanding regarding their presence in eutrophic lakes. The main purpose of this study was to investigate the diversity and abundance of comammox bacteria in a eutrophic lake and the effects of sewage discharge on bacterial abundance. Samples were taken from five areas of Lake Tangxun, China, i.e., a water chestnut (Trapa natans) area, a lotus (Nelumbo) area, a bare sediment area, a food sewage disposal area, and a domestic sewage disposal area. The diversity of comammox bacteria and the abundance of ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), comammox bacteria, and anaerobic ammonia-oxidizing (anammox) bacteria were measured. Comammox bacteria were widely found in Lake Tangxun and were closely related to Candidatus Nitrospira nitrosa and Candidatus Nitrospira inopinata. The abundance of the comammox amoA gene was lower in the two sewage discharge areas (1.3 × 107 copies g−1) than in the emergent plant areas (1.75 × 108 copies g−1) and the bare sediment area (1.0 × 108 copies g−1). The abundance of the comammox amoA gene at the five sampling areas was higher than that of the AOA amoA gene and AOB amoA gene, which indicated that comammox bacteria had a growth advantage in this eutrophic lake. Comammox bacteria were found in eutrophic lake sediments, and these bacteria belonged to comammox clade A. The abundance of comammox bacteria in the two sewage discharge areas was the lowest, indicating that they could survive in eutrophic waters, but eutrophication inhibited their growth.

Sewage discharges in oceanic islands: effects and recovery of eulittoral macrofauna assemblages

Sewage discharges are among the most common anthropogenic stressors on rocky shores. However, studies on benthic invertebrates’ responses to sewage pollution on insular assemblages are rare. In order to fulfil this gap, (i) the effects of sewage pollution and (ii) the recovery capacity of eulittoral insular assemblages were examined. The study was conducted on Terceira Island (Azorean Archipelago, Portugal), in four distinct areas: one impacted area (outfall in operation), one post-impacted area (decommissioned outfall) and two undisturbed reference areas. Results showed that the abundance of the dominant species changed between reference and impacted areas. More specifically, the abundance of limpets Patella candei, and barnacles Chthamalus stellatus decreased, while the abundance of littorinids Tectarius striatus and Melarhaphe neritoides increased near the sewage discharges. Seventeen months after removal of the outfall, limpet and barnacle populations had partially recovered, but littorinid populations had still not fully recovered. This study confirms the negative effects of sewage discharges on eulittoral assemblages, and provides information on the resilience of benthic species following the cessation of sewage disposal.

Are eulittoral assemblages suitable for detecting the effects of sewage discharges in Atlantic and Mediterranean coastal areas?

The search for cost-effective indicators able to detect anthropogenic impacts is an essential prerequisite to plan mitigation interventions, which can prevent further deterioration of coastal areas. Eulittoral assemblages are accessible for sampling, and their dominant species are easy to identify and widely distributed. This study assessed the potential of eulittoral assemblages to reflect environmental perturbations related to sewage discharge across different environmental and geographical locations. Sampling occurred in impacted (near sewage discharge) and control areas, on both Atlantic and Mediterranean shores. Multivariate analyses showed that the structure of eulittoral invertebrate assemblages differed significantly between control and impacted areas for the Mediterranean, but not for the Atlantic case study. Macroalgae responses to sewage discharge were found on the Mediterranean shore with a significantly higher abundance of Chlorophyta near the outfall. Limpet populations of the genus Patella appear to be affected by sewage discharge. The response of limpet populations differed between Atlantic and Mediterranean shores, probably due to among-species differences of ecological traits. Our results suggest that the response of eulittoral assemblages and limpets to sewage discharge might be strictly context-dependent, thus limiting their potential to serve as general indicators in monitoring the effects of this source of human impact over large spatial scales.

Trace Elements in Edible Rocky Shore Species: Effect of Sewage Discharges and Human Health Risk Implications

ABSTRACTSewage pollution is a worldwide concern and can result in increasing levels of trace elements in the environment that can pose serious risks both to wildlife and human health. This highlights the importance of studying the role of sewage discharges in the contamination of aquatic systems, especially in rocky shores, since part of our food resources is directly collected from coastal waters. For this purpose, the accumulation of trace elements (Cu, Zn, Pb, Ni, Co, Cd, Fe, Mn, and As) by edible molluscs (Mytilus galloprovincialis, Patella ulyssiponensis, and Phorcus lineatus) was compared between one sewage-impacted area and two reference areas.This study suggests that the concentrations of trace elements in the soft tissues of the selected molluscs can be affected by the presence of sewage discharges, and that limpets seem to be the best bioindicator. Moreover, the sewage pollution increased the concentrations of As in the mollusc species, emphasizing its potential damaging effects on natural systems and on edible species.

Effects of Sewage Discharge on Trophic State and Water Quality in a Coastal Ecosystem of the Gulf of California

This paper provides evidence of the effects of urban wastewater discharges on the trophic state and environmental quality of a coastal water body in a semiarid subtropical region in the Gulf of California. The concentrations of dissolved inorganic nutrients and organic matter from urban wastewater primary treatment were estimated. La Salada Cove was the receiving water body and parameters measured during an annual cycle were temperature, salinity, dissolved oxygen, nitrite, nitrate, ammonia, orthophosphate, and chlorophyll a. The effects of sewage inputs were determined by using Trophic State Index (TRIX) and the Arid Zone Coastal Water Quality Index (AZCI). It was observed that urban wastewater of the city of Guaymas provided 1,237 ton N yr−1 and 811 ton P yr−1 and TRIX indicated that the receiving water body showed symptoms of eutrophication from an oligotrophic state to a mesotrophic state; AZCI also indicated that the environmental quality of the water body was poor. The effects of urban wastewater supply with insufficient treatment resulted in symptoms of eutrophication and loss of ecological functions and services of the coastal ecosystem in La Salada Cove.

Effects of sewage discharges on lipid and fatty acid composition of the Patagonian bivalve Diplodon chilensis

Lipid and fatty acid (FA) composition and selected oxidative stress parameters of freshwater clams (Dipolodon chilensis), from a sewage-polluted (SMA) and a clean site, were compared. Trophic markers FA were analyzed in clams and sediment. Saturated FA (SAFA), and bacteria and sewage markers were abundant in SMA sediments, while diatom markers were 50% lower. Proportions of SAFA, branched FA, 20:5n−3 (EPA) and 22:6n−3 (DHA) were higher in SMA clams. Chronic exposure of D. chilensis to increasing eutrophication affected its lipid and FA composition. The increase in EPA and DHA proportions could be an adaptive response, which increases stress resistance but could also lead to higher susceptibility to lipid peroxidation TBARS, lipofuscins (20-fold) and GSH concentrations were higher in SMA clams. FA markers indicated terrestrial plant detritus and bacteria are important items in D. chilensis diet. Anthropogenic input in their food could be traced using specific FA as trophic markers.

Will improving wastewater treatment impact shorebirds? Effects of sewage discharges on estuarine invertebrates and birds

AbstractHuman communities often discharge wastewaters into estuaries, influencing their organic and pollutant loading, benthic community and trophic structure. The implementation of the Water Framework Directive has encouraged the treatment of wastewater discharges across European estuaries, but the implications for invertebrate and waterbird communities are poorly understood. We explore the effects of untreated sewage discharges on the distribution and abundance of foraging black‐tailed godwits Limosa limosa and their main benthic prey (bivalves and polychaetes) on the Tejo estuary in Portugal, a major European Special Protection Area with ongoing wastewater improvements. Patches of mudflat in close proximity to sewage streams (<30 m) can support polychaete densities and biomass that are an order of magnitude higher than more distant sites (>70 m), and godwits foraging in these areas can attain the highest intake rates recorded for the estuary. However, high intake rates can also be attained on bivalve prey, and bivalve biomass and density increase slightly with distance from sewage streams. As the organic input from sewage outfalls influences invertebrate abundance and godwit foraging rates over relatively small areas, the ongoing implementation of a sewage treatment network on the Tejo estuary seems likely to have only a limited impact on the wintering godwit population. The localized effect of untreated sewage discharges on benthic communities suggests that the implications for predatory birds are relatively minor where alternative prey are available, but may be more severe in locations with more depauperate, polychaete‐dominated invertebrate communities.

The effect of sewage discharge on the ecosystem engineering activities of two East African fiddler crab species: Consequences for mangrove ecosystem functioning

A number of studies have suggested that mangrove forests and their faunal components may be pre-adapted to the impact of organic waste discharge, making them possible natural wastewater treatment wetlands. However, the results from recent research are contradictory. Some studies have shown that negative effects, sometimes subtle and difficult to observe, can be detected on specific biotic components of forests subjected to organic pollution. Therefore, the aim of the present study was to investigate possible alterations in the ecosystem engineering activities of a fiddler crab community dominating the landward belts of Kenyan mangrove forests. The total processed sediment produced by burrowing and foraging activities in a population from a peri-urban mangrove area receiving untreated domestic sewage was compared with that from a forest not affected by urban wastewater. The results showed how the peri-urban site hosted a higher biomass of crabs, which produced a significantly lower amount of processed sediment compared with the pristine site, resulting in a lower total top sediment mixing activity of the crabs. Thus, the present study showed a link between sewage exposure and top sediment reworking by crabs, which is potentially beneficial for mangrove growth and ecosystem functioning. This represents a possible example of cryptic ecological degradation in mangal systems.

Corrigendum to: Effects of sewage discharges on microbial components in tropical coastal waters (Senegal, West Africa)

Coastal ecosystems are frequently submitted to anthropogenic pressure but little is known about how the dynamics of aquatic communities can be altered. The impact of urban and industrial discharges on microbial plankton was studied in Hann Bay near Dakar (Senegal) on the Atlantic Ocean. Spatial patterns were studied using three transects, with a total of 20 stations, during two periods in May and November (before and after the seasonal upwelling), revealing a clear contrast between near shore stations and the intermediate and seaward stations. In November, phytoplankton were associated with dissolved nutrient availability (e.g. with nitrate, r = 0.76) whereas in May, phytoplankton were more correlated with microbial variables (e.g. with heterotrophic nanoflagellates, r = 0.63). Most samples (40) failed to meet the quality levels for the faecal indicator bacteria (FIB) defined by the European Union bathing water quality directive. The topography plays a major role in water circulation explaining the presence of FIB at the seaward stations. The high prevalence of FIB during the two periods suggests chronic pollution and a potential risk to recreational swimmers and fish consumers in Hann Bay. Thus, as demonstrated in various temperate systems, the decline of water quality constitutes a serious problem in many West African countries.

Effects of sewage discharges on microbial components in tropical coastal waters (Senegal, West Africa)

Coastal ecosystems are frequently submitted to anthropogenic pressure but little is known about how the dynamics of aquatic communities can be altered. The impact of urban and industrial discharges on microbial plankton was studied in Hann Bay near Dakar (Senegal) on the Atlantic Ocean. Spatial patterns were studied using three transects, with a total of 20 stations, during two periods in May and November (before and after the seasonal upwelling), revealing a clear contrast between near shore stations and the intermediate and seaward stations. In November, phytoplankton were associated with dissolved nutrient availability (e.g. with nitrate, r = 0.76) whereas in May, phytoplankton were more correlated with microbial variables (e.g. with heterotrophic nanoflagellates, r = 0.63). Most samples (40) failed to meet the quality levels for the faecal indicator bacteria (FIB) defined by the European Union bathing water quality directive. The topography plays a major role in water circulation explaining the presence of FIB at the seaward stations. The high prevalence of FIB during the two periods suggests chronic pollution and a potential risk to recreational swimmers and fish consumers in Hann Bay. Thus, as demonstrated in various temperate systems, the decline of water quality constitutes a serious problem in many West African countries.

Environmental assessment of water-courses of the Turvo Limpo River basin at the Minas Gerais State, Brazil

A study was performed to evaluate the environmental contamination in the Turvo Limpo River basin which receives effluent discharges from domestic (residential and commercial) activities. The watercourses examined were the São Bartolomeu Stream, Turvo Sujo River, and Turvo Limpo River, located in the Minas Gerais State, Brazil. Water samples were collected at the river-side and analyzed for evaluation of pollutant inputs. The pH, temperature, electrical conductivity, redox potential (Eh), dissolved oxygen (DO), total and settleable solids, visual color, hardness, chemical oxygen demand (COD), biochemical oxygen demand (BOD), chloride, total phosphate, total nitrogen, ammonia nitrogen, nitrate, total coliforms and E. coli, as well as the Cd, Pb, Cu, and Zn speciation were determined in the watercourses. The data obtained were compared with those of the Brazilian Environmental Standards and with data from non-contaminated areas. River water characteristics in some sites were far from the limit values established for superficial waters with satisfactory quality. For instance, the BOD values reached 411 mg L(-1) for a maximum limit of 10.0 mg L(-1), while the ammonia nitrogen concentration reached 28 mg L(-1) for a maximum limit of 13.3 mg L(-1). Some sites showed E. coli values above those of non-contaminated regions. Besides the effects of sewage discharges into the water-courses, agriculture activities and the use of the area for cattle husbandry influenced the quality of the river waters, for instance, the pH of a spring-water sample reached the value of 4.3. The São Bartolomeu Stream has been contributing to the deterioration of the water quality of the Turvo Sujo River, while the Turvo Limpo River has also been affected by anthropogenic discharges in the Turvo Sujo River. The speciation of Cd, Cu and Pb showed that these metals were mainly found in the particulate fraction (i. e., associated with the suspended material). Fifty five percent of the water samples showed labile Zn concentrations greater than that of the nonlabile Zn.

Changes in Copper Speciation and Geochemical Fate in Freshwaters Following Sewage Discharges

The main factors determining the geochemical fate of copper in urban freshwaters affected by raw sewage discharges were investigated in this work. Water samples from the Irai and Iguacu rivers were collected monthly during a 1-year period at two points located upstream and downstream from the city of Curitiba, in Brazil. Results revealed that raw sewage discharges from the heavily urbanized area caused an enhancement of humic-coated suspended solids in the Iguacu River. In these waters copper is predominantly associated with the humic-coated particles whereas in the Irai River copper was found primarily in the aqueous phase. The transfer of copper from the aqueous to the solid phase changed its physical speciation along the watercourse. Thus, aspects related to the overall transport of trace metals in watercourses become an important issue to be considered in further studies concerning the effect of sewage discharges on the geochemical speciation and fate of trace metals in urban rivers.

The effects of sewage discharge on water quality and phytoplankton of Hawai'ian coastal waters

The effects of sewage discharge on algal populations and the quality of Hawai'ian coastal waters were investigated. Two outfalls were studied. One discharges primary treated sewage and the other discharges secondary treated sewage but are otherwise similar. This enabled comparisons of the effects of these different levels of treatment on the water quality and algal productivity of receiving waters. Plumes were followed and repeatedly sampled in a time-series manner. Rhodamine dye was used as a conservative tracer to compare the dilution behavior of the plume constituents MRP, NO 3+NO 2, NH 4, Silicate, TDP, TDN, total bacteria, PC, and PN. Rates of initial dilution ranged from two to almost three orders of magnitude, and were in reasonable agreement with engineering model predictions. Dilution of plume constituents approximated that of Rhodamine until background concentrations were reached, typically within 10 min of discharge. Chl a concentrations did not increase through time in the primary sewage plume but did increase up to 30% in the secondary sewage plume. However, rates of far-field dilution were so rapid that the increase could not have been due to algal growth. The increase was attributed to the plume mixing with a water mass whose relative chl a concentrations were greater. Rates of secondary dilution ranged from 2 to 3 orders of magnitude resulting in total dilutions of 10 5–10 6 within 3 h of discharge. These rates of secondary dilution were much greater than model predictions. From a nutrient standpoint, secondary treatment exhibited no advantages over primary treatment because dilutions were so rapid.

The effects of sewage discharge on shallow hard substrate sessile assemblages

On rocky shores, sewage discharges can modify natural distribution patterns of sessile organisms. The impact of sewage on shallow hard substrate assemblages has been assessed along SW Apulian coast (Ionian Sea, Italy), providing a framework to evaluate the benefits of future sewage displacement to deeper waters. Four locations (three controls and one putatively impacted) were selected and three sites were chosen at each location. Each site was sampled by 10 replicate photographic records. Univariate analyses revealed that the outfall did not affect the spatial distribution of number of taxa, total cover and abundance of some dominant taxa (mostly algae, sponges and bryozoans). The outfall negatively influenced the natural distribution pattern of filamentous green algae, whilst some algae (i.e. Gelidiales and Colpomenia sinuosa) were exclusively present at the impacted location. Multivariate analyses revealed that the outfall heavily modified the natural pattern of variability in the structure of the assemblage.

Variation in Clutch Size of the Common Eider: A Study Based on 41 Breeding Seasons on Coquet Island, Northumberland, England

--The clutch size of the Common Eider (Somateria mollissima) nesting on Coquet Island, Northumberland, UK has been studied for 41 successive years, during which time there has been a progressive decline in the annual mean clutch size, from a peak in 1962 of 5.37 eggs per nest to 3.43 eggs in 1996. There is evidence of a density-dependent relationship between clutch size and numbers of adult ducks from 1958 to 1981, but since 1982 the relationship has changed significantly and there has been a positive correlation between clutch size and numbers of adult ducks. In the early years of the study, the mean clutch size laid by young birds was lower than those laid by older birds, but this effect has been lost in recent years, apparently associated with the overall decline in clutch size. Clutch size did not change with age after the first breeding attempt. Comparisons of annual average clutch sizes for ten years' results from the Sands of Forvie, and for twelve years from The Netherlands, with those in the same years on Coquet Island showed no significant correlations. The mean clutch size in the sample of birds captured each year was significantly higher than that in the birds which left the nest early on the observer's approach. This could be an age effect or reflect the general body condition of the birds. I suggest the decline in clutch was caused by a deterioration in the food of the eider around Coquet Island, which in turn is possibly linked with an effect of sewage discharges on mussel beds. The eider appears to be a very suitable species for monitoring environmental conditions of inshore waters near its breeding sites, through systematic recording of clutch size and numbers of adults. Received 28January 1999, accepted 22 May 1999.

The Effect of Sewage Discharge On Water Quality Off the Coast of Alexandria in Spring and Summer

Abstract Water samples were taken from 7 transects at El-Anfushy, Eastern Harbour, El-Ebrahymea, Stanly, Gleem, Sidi-Bishr and El-Asafra along the coast off Alexandria. the area lies between latitude 31°10′ and 31°20′ N and longitude 29°55′ and 30° E. Nitrate, nitrite, ammonium, urea, dissolved inorganic phosphate, silicate and pH values were measured with average values 1,13, 0.43, 1.41, 1.21, 1.71, 7.16 μmol l−1, respectively. the investigated area is considered to be eutrophic. Levels of nutrients measured in 1991 are all significantly higher than those found in the same area in 1976.

Effects of sewage discharge, fishing pressure and habitat complexity on coral ecosystems and reef fishes in Hawaii

Effects of sewage discharge, fishing pressure and habitat complexity on coral ecosystems and reef fishes in Hawaii

Effects of sewage discharge, fishing pressure and habitat complexity on coral ecosystems and reef fishes in Hawaii

The major factor controlling the abundance of reef fishes in Hawaii (USA) appears to be habltat complexity (bottom topographic relief and interstitial space) Fishes aggregate In areas of h ~ g h hab~tat complexity at b~o~nass levels whlch, in areas protected from fishing, may significantly (by 2 to 5 times) exceed levels supported by pnmary production within the ecosystem. High relief natural areas 'act' like artificial reefs in terms of aggregating fishes. Reef fish abundance is also affected by fishing pressure in the main Hawaiian Islands. Areas protected from fishing (Marine Life Conservation Districts, MLCDs) support standing crops of reef fishes that average about 45 g m-2 higher than areas open to fishing. In areas unprotected from fishing, reef fish abundance has significantly declined in recent years. Conservation and management of reef fishes would be ~mproved if more hlgh relief areas were protected from fishing. Thus far. 11 MLCDs have been established in such areas In Hawaii. The discharge of primary or secondary treated sewage effluent into the ocean in Hawaii through deep ocean outfalls causes no apparent negative environmental impact to coral reef ecosystems. Deep ocean outfalls in fact attract reef fishes. Increases in abundance around the outfalls appears to result from increased habitat complexity brought about by the construction of the pipelines and surrounding caprock and concrete. A small amount of the variability (Increase) in reef flsh abundance around the outfalls may also be due to food subsidies (particulate organlc matter) in the effluent. No species of fish, coral, invertebrate or algae at the outfalls exhibited any pathological symptoms. Hence, statewide declines in reef fish abundance in areas unprotected from fishing are not related to the discharge of sewage effluents via deep ocean outfalls. Rather, these declines appear to have been caused by overfishing.