Municipal Sewage Discharge Research Articles

Assessment of Metal Contamination in Surface Sediments of Jiaozhou Bay, Qingdao, China

AbstractAn assessment of metal contamination in surface sediments of the Jiaozhou Bay, Qingdao, one of the rapidly developing coastal economic zones in China, is provided. Sediments were collected from 10 stations and a total of 15 heavy metals were analyzed. Concentrations of metals show significant variability and range from 210 to 620 ppm for Ti, 2.7 to 23 ppm for Ni, 4.2 to 28 ppm for Cu, 5.2 to 18 ppm for Pb, 12 to 58 ppm for Zn, 0.03 to 0.11 ppm for Cd, 5 to 51 ppm for Cr, 1.5 to 9.9 ppm for Co, 5.3 to 19 ppm for As, 12 to 32 ppm for Se, and 19 to 97 ppm for Sr. Based on concentration relationships and enrichment factor (EF) analyses, the results indicate that sediment grain size and organic matter played important roles in controlling the distribution of the heavy metals in surface sediments of the Jiaozhou Bay. The study shows that the sediment of the Jiaozhou Bay has been contaminated by heavy metals to various degrees, with prominent arsenic contributing the most to the contamination. The analysis suggests that the major sources of metal contamination in the Jiaozhou Bay are land‐based anthropogenic ones, such as discharge of industrial waste water and municipal sewage and run‐off. Notably, the elevated heavy metal concentrations of the Jiaozhou Bay sediments could have a significant impact on the bay's ecosystem. With the rapid economic development and urbanization around the Jiaozhou Bay, coastal management and pollution control should focus on these contaminant sources, as well as provide ongoing monitoring studies of heavy metal contamination within the bay.

Cumulative impacts assessment along a large river, using brown bullhead catfish (Ameiurus nebulosus) populations

The effects of point-source and diffuse discharges on resident populations of brown bullhead catfish (Ameiurus nebulosus (LeSueur, 1819)) in the Waikato River (New Zealand) were assessed at sites both upstream and downstream of point-source discharges. At each site, the population parameters, relative abundance, age structure, and individual indices, such as condition factor, organ (gonad, liver, and spleen) to somatic weight ratios, and number and size of follicles per female, were assessed. Physiological (blood), biochemical (hepatic ethoxyresorufin-O-deethylase [EROD] and plasma steroids), and other indicators (bile chemistry and liver metals) of exposure or response also were measured. No impacts on brown bullhead health were obvious at individual geothermal, municipal sewage, or thermal discharge sites or cumulatively along the river. Brown bullhead from the bleached kraft mill effluent site showed elevated levels of EROD, decreased numbers of red blood cells, increased numbers of white blood cells, and depressed levels of sex steroids. However, growth rates, condition factor, age structure, and gonadosomatic index suggest that discharges with significant heat or nutrients benefit catfish despite physiological impairment at one site. Consideration of brown bullhead population-level responses to discharges in a monitoring framework revealed three different population-level response patterns resulting from the point-source discharges.

Detailed Endocrine Assessments of Wild Fish in the Northern River Basins, Alberta, in Comparison to EEM Monitored Endpoints

Abstract During the Northern River Basins Study (NRBS), several issues were highlighted regarding the health of resident fish populations. Based on a basin-wide study of gonad morphology and circulating sex steroid levels, there was preliminary evidence of potential endocrine disruption in fish within the basins. The main concern with this was the potential loss of reproductive capability and possible declining populations. The Northern Rivers Ecosystem Initiative was established in response to the NRBS and an endocrine study was conducted to evaluate in more detail reproductive endocrine function of fish within the identified areas. A suite of endocrine endpoints was used and compared to overall fish health assessments using the Environmental Effects Monitoring (EEM) Programs protocol in areas exposed to sewage and pulp and paper mill effluents. As these northern rivers are nutrient-limited, fish responded to effluent addition (increased nutrients) by showing signs of increased growth and development relative to the upstream reference fish. Some signs of altered reproductive function were observed downstream of the one mill site, however additional responses were observed downstream of a municipal sewage treatment plant discharge from the neighbouring community. The reproductive responses were minimal compared to earlier studies at other older pulp and paper facilities. Follow-up studies at the Grande Prairie site documented changes in the fish responses to the effluents in terms of enrichment. The sewage treatment plant had installed tertiary treatment prior to the latest studies and reductions in the release of nutrients may be the cause. It is not known at the present time whether the pronounced eutrophication response that is still present in these fish may mask other endocrine alterations, as these effluents have endocrine-active compounds in them. The results also emphasize the need for EEM-like monitoring downstream of municipal sewage discharges.

Oxidative stress responses in longnose sucker ( Catostomus catostomus) exposed to pulp and paper mill and municipal sewage effluents

While recent evidence indicates that the generation of reactive oxygen species (ROS) and associated oxidative damage are frequently observed in fish populations with exposure to pulp and paper mill effluents, the potential for ROS generation from municipal sewage effluents has not been addressed. This study investigates the utility of measures of oxidative stress in delineating the effects of both pulp and paper mill and municipal sewage discharges. Longnose sucker ( Catostomus catostomus) were collected below three pulp and paper mill and two municipal sewage effluent discharges over a 3-year period within the Wapiti and Athabasca River systems in northern Alberta. Biochemical responses in longnose sucker varied between the two rivers systems, with more pronounced changes occurring within the Wapiti River. Of the suite of biochemical parameters examined, fatty acyl-CoA oxidase (FAO) activity was the most sensitive indicator of pulp and paper mill exposure, but was only infrequently induced with exposure to municipal sewage effluent. Hepatic and gonadal 2-thiobarbituric acid reactive substances, lipid hydroperoxides, and hepatic free iron were less consistently elevated with exposure to pulp and paper mill effluent than FAO activity, and were also only infrequently altered with sewage effluent exposure. Hepatic ascorbic acid, liver somatic index, and condition factor were consistently altered with exposure to both sewage and pulp and paper mill effluents. While specific biochemical and organismal responses varied with effluents and time, the collective suite of oxidative stress endpoints proved to be useful tools in identifying relative influences of municipal sewage and pulp and paper mill effluent on fish populations in adjacent receiving waters.

Rapid assessment of rivers using macroinvertebrates: the role of experience, and comparisons with quantitative methods

We assessed rapid biological assessment (RBA) of macroinvertebrate communities in comparison with quantitative sampling at 18 pairs of river sites in south-eastern Australia. One member of each pair served as a reference site and the other was affected by mild to moderate human disturbance from a point or diffuse source (fish farm effluents, small municipal sewage discharges, a dam, agriculture and grazing). Samples were taken from riffles, stream edges and rocks in pools, mostly using hand nets (RBA) and Hess samplers (quantitative). Macroinvertebrates in RBA samples were always subsampled by live-picking by eye on site for 30 min. Comparisons were made between novice operators (university undergraduates) and experienced river biologists in the application of RBA, including sample identification. Quantitative samples were collected only by experienced river biologists, preserved and picked under stereomicroscopes in the laboratory, either in their entirety or after mechanical subsampling. Specimens were identified to family level for both methods. Novices recorded slightly fewer families than experts and misidentified some specimens, and expert data for the same site and habitat were on average more consistent than novice data. Nevertheless, Procrustes analysis of ordinations showed that differences between RBA and quantitative data did not depend on the type of RBA operator. And regardless of the operator, RBA data were better than quantitative data at discriminating between reference and disturbed sites for all three habitat types. We conclude that this type of RBA is sensitive and cost-effective, and we recommend improvements to inter-operator consistency.

Silicate as the limiting nutrient for phytoplankton in a subtropical eutrophic estuary of Taiwan

The estuary of Tamsui River, located in the northern subtropical area of Taiwan, is eutrophic as a result of municipal sewage discharges from the Taipei metropolitan area. The primary productivity is rather low in this estuary, compared with other estuaries. The objective here was to determine whether nutrient limitation might explain the decreasing productivity that has occurred in the last two decades. Comparison of phytoplankton biomass between four sampling sites revealed a trend of decreasing growth, associated with increasing dominance of diatoms, along a gradient moving towards the mouth of the estuary. This trend corresponded with a spatial gradient in nutrient concentrations among the study sites, which resulted from a mixture of heavily polluted river water with less polluted marine water. An in vitro nutrient enrichment bioassay was done with additions of nitrogen, phosphorus, and silicate to estuarine water containing the natural phytoplankton communities. The results indicated that enrichment with silicate gave rise to a greater enhancement in phytoplankton biomass, mainly of diatoms, than did enrichment with nitrogen or phosphorus. Chemical analysis of estuarine water indicated that non-biogenic fraction of silicate might be depleted at flow tide, giving rise to imbalanced nutrient supply and thus a lowering of primary productivity. In this estuary, the imbalance of nutrient supply resulted from increasing water pollution is possibly the cause of the decrease in productivity over last several decades.

Treated municipal sewage discharge affects multiple levels of biological organization in fish

The objectives of this study were to examine cellular-, organ-, and organism-level responses in longear sunfish ( Lepomis megalotis) and fish community structure in a stream in which treated municipal sewage effluent is discharged and in a nearby reference stream with little surrounding land use. A modified version of the U.S.E.P.A. Rapid Bioassessment Protocol V, which combines a habitat assessment with Karr's index of biotic integrity, was used on 400-m reaches of each stream. The study site had a higher proportion of tolerant species and omnivores and a lower proportion of top predators, suggesting alterations in the fish community and a slight level of water quality impairment. Significant increases in condition factor, hepatosomatic index, serum testosterone, and plasma vitellogenin concentrations were observed in male sunfish collected from the study stream in comparison to fish collected from the reference stream. There were no differences between sites in hepatic expression of the 70-kDa stress protein (HSP70). In conclusion, effects were observed at cellular, organ, organism, and community levels of biological organization in fishes exposed to treated municipal sewage effluent.

The Pollution and Protection of the Inner Oslofjord: Redefining the Goals of Wastewater Treatment Policy in the 20thCentury

The main source of pollution in the inner Oslofjord in the 20th century has been municipal sewage discharges from the city of Oslo. At the beginning of the 20th century, pollution was limited to the coastal waters and the harbor area of Oslo, in the vicinity of sewer outlets. High bacteria content caused a health hazard that city authorities attempted to reduce by constructing a sewerage system, including intercepting sewers and wastewater-treatment plants. Due to population growth, the impact area of increasing wastewater loading expanded. The entire inner Oslofjord was found to be affected in the 1930s. Scientific studies linked municipal sewage discharges to an increase in the algal production. In the 1940s, the bottom layers were found to be anoxic. The Oslo sewerage authorities were aware of the fjord's pollution, but regarded organic matter as the major problem and the activated sludge method as the best solution. The role of nutrients was not commonly acknowledged until in the late 1960s. Phosphorus removal was taken into use in the 1970s, and nitrogen removal was introduced in the late 1990s. Removal of nutrients has resulted in the slow recovery of the fjord.

Spatial distribution and accumulation of heavy metals in tidal flat sediments of Shanghai coastal zone

Surface and core sediments from the high, middle and low tidal flats of Shanghai coastal zone were analyzed for heavy metal (e.g. Cu, Pb, Zn, Cr, Cd, Fe, Mn) concentrations. Besides Cd, the concentrations of Cu, Zn, Cr and Pb are 2–5 times higher than their background values and show serious pollution trend due to the direct discharge of industrial and municipal sewage along the Shanghai tidal flat, as well as the wet and dry depositions of industrial dusts. It seems that heavy metals prefer to accumulate and be enriched in the sediments near large sewage outlets, high flats, and the subsurface layer at the depth of 10–30 cm. Several main factors, which include the direct sewage discharge along the tidal flat, tidal hydrodynamic action, large engineering activity, early diagenesis and windstorm tide, are considered to be responsible for influencing spatial distribution patterns of heavy metals in the Shanghai tidal flat.

Dissolved oxygen decline in ice-covered rivers of northern Alberta and its effects on aquatic biota

To determine whether existing dissolved oxygen (DO) regulationswere adequate to protect riverine biota, the Northern River Basins Studyrequired a research and assessment program to establish the effect ofpulp mill and municipal sewage discharges on under-ice DO concentrationsand aquatic biota in the Athabasca, Wapiti and Smoky rivers of northernAlberta, Canada. Analysis of monitoring data collected over >30 yearsshowed that pulp mill and municipal effluents have caused “sags” in DObelow their discharges and contributed to an increased rate of declinein DO over 10s of kilometers in the Wapiti-Smoky rivers or 100s ofkilometers in the Athabasca River. To permit forecasting of DO declinesin response to changes in river discharge or effluent biochemical oxygendemand (BOD), a one-dimensional steady-state river water quality modelwas implemented that successfully (r2 =0.74–0.92) predicted DO concentrations over an 820 km reach of theAthabasca River for the 1990–1994 winters. Experiments on nativefish and benthic macroinvertebrate species showed that exposure to lowDO and low temperatures (2–3°C) caused delays in hatch ofmountain whitefish eggs (at 6.5 mg/L DO), reduced mass of bull troutalevins post-hatch (at 5.0 mg/L DO), extended the spawning period ofburbot (at 6.0 mg/L DO), and depressed feeding rates and loweredsurvival of the mayfly Baetis tricaudatus (at 5 mg/L DO).As a result of recommendations from this integrated program of rivermonitoring, modelling and experimentation, effluent BOD loading has beenreduced to the Athabasca and Wapiti rivers and the provincial DOguideline for protection of aquatic life has been increased from 5.0 to6.5 mg/L.

Occurrence of butyltin residues in sediment and mussel tissues from the lowermost tennessee river and Kentucky lake, U.S.A.

Surface sediments and mussel samples were collected at six selected locations in the lowermost Tennessee River and Kentucky Lake, U.S.A. and analyzed for butyltin (BT) derivatives. In sediments, total BT concentrations ranged from 6.8 to 356 ng g −1 dry wt. A wide range of concentrations in sediments suggested the presence of localized area of contamination. In mussel tissues, total BT concentrations varied between 26–107 ng g −1 dry wt. BT levels were comparable to the levels reported in mussels from some coastal sites as well as a few freshwater ecosystems. Leaching of tributyltin-containing anti-fouling paints in the ocean-going ships is a source of tributyltin, and discharge of municipal sewage and industrial waste waters in to this watershed may account for the presence of the monobutyltin and dibutyltin derivatives detected in the samples. To our knowledge, this is the first report on the butyltin concentrations in sediment and mussel tissues from the lowermost Tennessee River and Kentucky Lake.

Toxicological characterization of sediments from Baie des Anglais on the St. Lawrence Estuary

The sediments of Baie des Anglais on the St. Lawrence Estuary have a history of environmental contamination, but no information exists relating to their toxicity. The purpose of the present study was to characterize three sites in and near Baie des Anglais, in terms of sediment toxicity and contaminants. Sites 1 and 2 within the Baie des Anglais are relatively close to local industry and municipal sewage discharge points, while Site 3 is outside the bay. Three microscale bioassays, Microtox® , echinoderm fertilization and Toxi-ChromoPad®, showed that sediments from Site 1 were the most toxic, followed by Site 2. Site 3 was non-toxic. While the solid phase Microtox® test did indicate that Site 1 was most toxic, the absolute response was weak. Liver cytochrome P450 lAl mRNA in American plaice ( Hippoglossoides platessoides), captured at Site 1 in the bay was significantly induced compared to the P450 system of plaice captured at Sites 2 and 3. Hepatic metallothionein mRNA levels were not significantly different between plaice captured at all three sites. Sediment chemical analyses revealed a gradient in polycyclic aromatic hydrocarbons, polychlorinated biphenyls and dibenzofurans (PCDF) with the highest levels recorded at Site l, about 10-fold less at Site 2 and 100-fold less at Site 3. Amongst the organochlorines the PCDF group were deemed the most important due to their prevalence and known toxicity. Heavy metal concentrations were low and representative of background levels for the St. Lawrence Estuary.

The effects of untreated municipal sewage discharge to the marine environment off Victoria, British Columbia, Canada

The Victoria area (British Columbia, Canada) discharges screened wastewater through two long deep outfalls (Macaulay and Clover Point) into an oceanic environment characterized by strong turbulent tidal flows. Monitoring of the receiving waters has indicated that conventional water quality parameters have not been affected by the discharges. Fecal coliform levels above the outfalls are periodically elevated but remain well below the swimming standard. Shoreline studies of fecal coliform levels have shown that the deep outfalls have not measurably affected water quality at beaches. Recently, monitoring efforts have concentrated on effects to the seafloor environment. At Macaulay Point, sediment chemical levels of concern were confined to within 100 to 400 m of the outfall. Similarly, sediment toxicity was detected at stations up to 400 m from the diffusers. This toxicity was limited to effects on growth and development. Survival was not affected. The benthic infaunal community exhibited a typical response to organic enrichment. Within 100 m of the outfall abundance was increased and richness depressed. At Clover Point sediment chemical levels of concern were confined to within 100 to 200 m of the outfall. Tissue chemistry of resident mussels showed no consistent pattern with distance from the outfall. Some tissue chemicals increased with distance from the diffuser while others decreased. Overall the impact of the outfalls on the seafloor was found to be minimal and restricted in extent.

Effects of trace chromium on organic adsorption capacity and organic removal in activated sludge

Heavy metals are commonly found in municipal sewage that contains industrial effluents. Metal concentrations above toxic levels inhibit biological processes in municipal sewage treatment works and discharge of metals into surface waters can have severe effects on the environment and public health. However, trace metals at sub-toxic concentrations have also been observed to affect COD removal in activated sludge. In this study, the effects of a trace metal (chromium) on activated sludge in a sequencing batch reactor (SBR) were investigated. Chromium-laden wastewater at a sub-toxic level of 0.05 mg/l affected the SBR performance to different extents depending on the hydraulic retention time (HRT). Organic removal in activated sludge was postulated to proceed by a rapid adsorption of organics on the sludge, followed by a slower metabolic assimilation mechanism. Heavy metal acted as a strong competitor for active sites on the sludge, hampering organic adsorption and affected the COD reduction efficiency under short HRTs of 2.5 days and below.

The effects of untreated municipal sewage discharge to the marine environment off Victoria, British Columbia, Canada

The Victoria area (British Columbia, Canada) discharges screened wastewater through two long deep outfalls (Macaulay and Clover Point) into an oceanic environment characterized by strong turbulent tidal flows. Monitoring of the receiving waters has indicated that conventional water quality parameters have not been affected by the discharges. Fecal coliform levels above the outfalls are periodically elevated but remain well below the swimming standard. Shoreline studies of fecal coliform levels have shown that the deep outfalls have not measurably affected water quality at beaches. Recently, monitoring efforts have concentrated on effects to the seafloor environment. At Macaulay Point, sediment chemical levels of concern were confined to within 100 to 400 m of the outfall. Similarly, sediment toxicity was detected at stations up to 400 m from the diffusers. This toxicity was limited to effects on growth and development. Survival was not affected. The benthic infaunal community exhibited a typical response to organic enrichment. Within 100 m of the outfall abundance was increased and richness depressed. At Clover Point sediment chemical levels of concern were confined to within 100 to 200 m of the outfall. Tissue chemistry of resident mussels showed no consistent pattern with distance from the outfall. Some tissue chemicals increased with distance from the diffuser while others decreased. Overall the impact of the outfalls on the seafloor was found to be minimal and restricted in extent.

Coal and deodorizer residues in marine sediments—contaminants or pollutants?

AbstractSediment studies around the diffuser of a relatively untreated major marine municipal sewage discharge indicated that 1,4‐dichlorobenzene (1,4‐DCB) and polycyclic aromatic hydrocarbons (PAHs) were among the contaminants of concern. Subsequent investigations revealed that elevated PAH concentrations were due to the shipwreck of a collier in the 1890s and were apparently not bioavailable. Coal is a common contaminant in marine and freshwater sediments and may be responsible, in some cases, for high PAH contaminant concentrations not resulting in pollution (i.e., biological effects) and can also affect total organic carbon measurements and normalizations. Little information exists regarding 1,4‐DCB, whose main source to sewage appears to be toilet block deodorizers and which appears to be a useful marker of the extent of contamination for untreated sewage discharges. Correlative analyses suggest it is a pollutant, but this remains to be confirmed by experimental testing.

Hydrocarbon and azaarene markers of coal transport to aquatic sediments

Hydrocarbon and azaarene concentrations and compositions vary systematically in 16 western Washington coal samples ranging in rank from lignite to anthracite. Sub-bituminous and bituminous samples within a vitrinite reflectance range of 0.4-0.8% R/sub 0/ contain hydrocarbon suites and azaarenes whose compositions correspond to those found in Puget Sound and Lake Washington sediments, as well as coal particles sieved from a Puget Sound core. These coals generate an overall lipid signal distinct from other fossil sources including street runoff and municipal sewage discharges. Thus, molecular markers demonstrate the transport of specific local coals to aquatic sediments in adjacent drainage basins resulting from erosion and mining activity.

Electrochemical determination of pollutants in sea water: Toxic substances and nutrients

Coastal marine waters have a wide variety of important human uses and therefore must be protected against contamination. The main sources of their pollution (by toxic substances and nutrients) are the discharge of municipal sewage and runoff from agricultural areas. Excessive nutrient enrichment in the form of inorganic nitrogen (NH 4 +, NO 2 −, NO 3 −) may be directly estimated by the use of ion selective electrodes (ISE), whereas the inorganic phosphorus can only be estimated indirectly. The total content of N, P and heavy metals may be estimated after decomposition of organic substances, using the ISE method in the case of P and N determination and the differential pulse anodic stripping voltammetry (DPASV) method for determining the heavy metals.

The effects of chlorinated municipal sewage and temperature on the abundance of bacteria in the Sheep River, Alberta

The intersite and temporal differences in the abundance of sessile and planktonic bacteria subjected to a chlorinated municipal sewage discharge and a thermal discharge were investigated in the Sheep River, Alberta, from January through December 1978. Significantly higher densities of both sessile and planktonic cells generally occurred within the chlorinated effluent plume. Higher numbers of sessile bacteria were also found below the thermal discharge, with maximum densities occurring in the late winter-early spring and minimum densities following mountain runoff. The higher numbers of sessile bacteria in the chlorinated plume was attributed to nutrient enrichment. These results indicate that chlorinated sewage effluent has no adverse effects on the abundance of sessile bacteria.