Domestic Wastewater Discharges Research Articles

A Preliminary Study on the Occurrence of Pharmaceutically Active Compounds in the River Basins and Their Removal in Two Conventional Drinking Water Treatment Plants in Chongqing, China

The occurrence of 21 selected pharmaceutically active compounds (PhACs) in river water was examined; meanwhile the presence and removal of these PhACs at different water treatment steps in two conventional drinking water treatment plants (DWTPs) were evaluated. Monitoring results showed that of all 21 target PhACs, twelve PhACs were ubiquitously detected in water samples from the Yangtze river and its two tributaries (Jialing River and Huaxi stream), whereas alodipine was not found in any river water sample. The concentrations of PhACs detected in Huaxi stream were statistically significantly higher than those found in the Jialing River and the Yangzi River because of the direct discharges of uncontrolled domestic sewage and poultry wastewater and the abuse of PhACs in the rural areas served by the Huaxi stream. An environmental risk assessment of PhACs based on the risk quotient value approach indicated that sulfamethoxazole, ofloxacin and dehydrated erythromycin and clofibric acid had a medium risk, and the mixture of the studied PhACs showed high risk for the aquatic ecosystems. Fourteen out of 21 target PhACs were found in the raw water of the two studied DWTPs with azithromycin having the highest concentration (about 20 ng/L). Following the conventional water treatment processes, the studied PhACs were found to be removed by an average of 54 and 48% in DWTP A and DWTP B, respectively. Among the target PhACs, six and three PhACs were detected in finished water of DWTP B and DWTP A, respectively. This is the first study in southwestern China reporting the presence of PhACs in surface water and drinking water.

Spatiotemporal distribution of the bacterial contamination of agricultural and domestic wastewater discharged to a drainage ditch (Sinaloa, Mexico)

The agricultural drainage water from the Sinaloa valley (Mexico) is often reused in agriculture and aquaculture before reaching coastal water bodies. Discharged water must be of good quality to maintain the health of ecosystems and prevent damage to the organisms that compose them. This research determined the occurrence of coliforms in a drainage ditch known as La Michoacana (Sinaloa) that receives contaminated water from agricultural and urban sources. A section of 3.6 km was studied during 2013 and samples were obtained monthly from five equidistant sampling sites. Each water sample was analyzed for total coliform (TC) and fecal coliform (FC) content, pH, salinity, temperature, and dissolved oxygen percentage (%DO). The sampling sites with the highest bacterial contamination were associated with direct discharges of domestic wastewater and those with the lowest to the output drain. The performance of this agricultural ditch decreased the concentration of coliforms, with median and average values of 96% and 87% for TC, and 98% and 85% for FC, respectively. The most common bacteria were Escherichia coli (67.7%), Kluyvera cryocrescens (10.2%), and Enterobacter agglomerans (6.3%). Coliform concentration was positively correlated with temperature and negatively with %DO. The ditch improved the microbiological quality of the water, demonstrating remediation activities in the system. Proper management and maintenance of agricultural drainage ditches would favorably impact the health and biodiversity, as well as the intensive aquaculture and agricultural activities of the Sinaloa valley.

Analysis of Discharge Characteristics of Typical Rural Domestic Wastewater along the Tuojiang River

Environmental pollution caused by rural domestic wastewater has become increasingly serious. However, data on the current characteristics of rural domestic wastewater are scarce. In this study, we selected typical villages along the Tuojiang River as study objects. We analyzed the pollution status and discharge characteristics of rural domestic wastewater along the Tuojiang River through field research in winter and summer. Data analysis and collection, as well as water monitoring, were performed to determine the water quality and quantity characteristics of the rural domestic wastewater. The per capita daily discharges of rural domestic wastewater along the Tuojiang River are 11.26–50.37 L in winter and 18.39–303.57 L in summer. Both the maximum and average concentrations of pollutants in the rural domestic wastewater are higher than those in urban domestic wastewater, but the per capita daily discharge of pollutants is clearly lower in rural areas than in urban areas. The analysis of the typical discharges of rural domestic wastewater along the Tuojiang River provides a valuable reference for rural wastewater discharge treatment planning and process selection.

Application of Constructed Wetland to Rural Domestic Wastewater Treatment in China

Constructed wetland is a new wastewater treatment technology. It not only is more effective in wastewater treatment, but also has good eco-landscapes value. According to the characteristics of domestic wastewater discharge in rural, constructed wetlands is a key technology to solving this problem in China. Application of constructed wetland to Chinese rural domestic wastewater treatment was reviewed in this paper. On this basis, the issues in the application of constructed wetland encountered, and future trends are discussed. On the one hand, constructed wetlands were prone to clogging and low nitrogen removal efficiency. On the other hand, some existing constructed wetlands were abandoned due to poor maintenance and management. Therefore, in order to play better the role of wastewater treatment, anti-blocking ability and denitrification efficiency of constructed wetlands should be improved. Meanwhile, the maintenance and management of constructed wetlands should be strengthened. Application of constructed wetlands in the rural area provides a strong guarantee for sustainable development of rural economy.

Phycoremediation of wastewaters: a synergistic approach using microalgae for bioremediation and biomass generation

Discharge of untreated domestic and industrial wastewater into aquatic bodies is posing a serious eutrophication threat, leading to a slow degradation of the water resources. A number of physical, chemical and biological methods have been developed for the treatment of wastewaters; among these, the use of microalgae is considered as a more eco-friendly and economical approaches. Microalgae are versatile organisms which perform multiple roles in the environment—bioremediation of wastewater, gleaning of excess nutrients and in turn, generate valuable biomass which finds applications in the food, biofuel and pharmaceutical industries. They are currently being utilized to reduce the high nutrient load (especially N and P) from wastewaters, which fulfill the growth requirements of microalgae, making it a suitable cultivation medium for biomass production. The present review represents a comprehensive compilation of reports on microalgal diversity of wastewaters, followed by a critical overview of their utilization, suitability and potential in bioremediation vis-a-vis biomass production. This review also emphasizes the superiority of polyalgal and consortial approaches in wastewater treatment, as compared to the use of unialgal inocula, besides providing useful pointers for future research needs in this area.

SMALL CONCENTRIC CONSTRUCTED WETLAND FOR TREATMENT OF DOMESTIC WASTEWATER IN A TEA ESTATE IN SRI LANKA

Water pollution due to indiscriminate discharge of domestic wastewater is one of the major issues limiting access to safe water. A study was conducted to characterize water use and effluent in communities in a tea estate in the upper watershed in Sri Lanka. A questionnaire survey, field visits and focus group discussions were conducted to quantify water consumption. At a pilot scale, concentric rings with diameters of 0.3, 0.75 and 1.5 m were used for constructed wetland. Aggregates and soil were used to fill the rings. Scirpus grossus and Nasturtium officinale were planted in the middle and outer rings respectively. Wastewater from a collection tank was fed into the inner ring and treated wastewater was discharged through the outer ring. Water was sampled at the inlet – at the inner ring, middle ring and outer ring for analysis of Biological Oxygen Demand (BOD5) and other quality parameters. Domestic water usage varied with income, education and access to water. Per capita daily water use was higher in high-income and medium-level educated people. Per capita daily water usage of stream water users and pipe-borne water users were 246 and 194 L, respectively. Major consumption was for bathing followed by laundry. BOD5 of greywater varied from 20-55 mg/L and was highly contaminated with total coliform and E coli. The pilot-scale constructed wetland showed higher removal efficiency of BOD5, SS and TDS at 85, 65 and 55%, respectively. The constructed wetlands were in concentric rings. The hydraulic retention time of 2.3 days increased the pathways and facilitated the filtration, biodegradation and plant uptake of nutrients. This system can be recommended for small communities in the upper watershed in Sri Lanka.

Spatial–temporal distribution and potential ecological risk assessment of nonylphenol and octylphenol in riverine outlets of Pearl River Delta, China

The aquatic environments of the Pearl River Delta in Southern China are subjected to contamination with various industrial chemicals from local industries. In this paper, the occurrence, seasonal variation and spatial distribution of alkylphenol octylphenol (OP) and nonylphenol (NP) in river surface water and sediments in the runoff outlets of the Pearl River Delta were investigated. NP and OP were detected in all water and sediment samples and their mean concentrations in surface water during the dry season ranged from 810 to 3366ng/L and 85.5 to 581ng/L, respectively, and those in sediments ranged from 14.2 to 95.2ng/g dw and 0.4 to 3.0ng/g dw, respectively. In surface water, much higher concentrations were detected in the dry season than those in the wet season. In sediments, the concentrations in the dry season were also mostly higher. High concentrations of NP and OP were found in Humen outlet, likely due to high levels of domestic and industrial wastewater discharges. An ecological risk assessment with the use of hazard quotient (HQ) was also carried out and the HQ values ranged from 3.6×10−5 to 35 and 64% of samples gave a HQ>1, indicating that the current levels of NP and OP pose a significant risk to the relevant aquatic organisms in the region.

Evaluation of Owabi Reservoir (Ghana) water quality using factor analysis

AbstractThe Owabi Reservoir receives water inflows from several streams that drain through the rapidly urbanizing towns in the Kumasi metropolis. The reservoir catchment had been encroached upon by various human activities, resulting in the generation of large volumes of waste water being discharged into streams draining to the reservoir. This study presents a comprehensive evaluation of the water quality of Owabi Reservoir. Water samples from 10 sampling sites within the reservoir were analysed for various water quality parameters; namely, pH, electrical conductivity (EC), sulphate (), phosphate (), chloride (Cl−), lead (Pb), arsenic (As), zinc (Zn), iron (Fe), copper (Cu), total dissolved solids (TSS), turbidity, faecal coliform and E. coli. The measured water quality parameters were compared to the guidelines proposed by the WHO for drinking water and natural background levels. Mean values for Pb, As, turbidity, TDS, faecal coliform and E. coli were greater than the WHO guidelines. Factor analysis for the measured parameters resulted in the extraction of five factors accounting for 83.13% of the total variance. Factor 1 showed strong loadings for , and TDS, reflecting a negative influence on the water quality by agricultural discharges. Factor 2 showed high loadings for EC, Cl− and apparent colour, while Factor 3 registered high loadings for colour and faecal coliform, suggesting domestic wastewater discharges and the presence of decaying organic matter. Factors 4 and 5 showed high loadings for copper, lead, turbidity and E. coli, an indication of both organic and inorganic pollution. Accordingly, periodic monitoring of Owabi Reservoir water quality, and the streams draining into it, is recommended as a means of ensuring good water quality, as well as facilitating the identification of the possible types and sources of water pollutants entering the reservoir.

Occurrence of polycyclic aromatic hydrocarbons in the Soan River, Pakistan: Insights into distribution, composition, sources and ecological risk assessment

Present study investigates the occurrence, distribution and sources of ∑17 polycyclic aromatic hydrocarbons (PAHs) in the surface water of Soan River, Pakistan. The concentrations of total PAHs ranged from 61 to 207ng/l. Low molecular weight (LMW) PAHs were recorded higher in concentrations (64.7 percent) as compared to high molecular weight (HMW) PAHs (35.6 percent). Principal component analysis (PCA) revealed domestic and industrial wastewater discharge, vehicular exhaust, petroleum residues and biomass combustion as the main sources for PAHs contamination. Using the USEPA toxic equivalency factor (TEF) approach: Benzo(a)Pyrene and Dibenzo(a,h)Anthracene contributed highly carcinogenic exposure equivalent. The surface water of the Soan River is found to be slightly polluted with PAHs thereby posing health risks to aquatic bodies.

Evaluating the leachable metals in Kaohsiung Harbor sediment using the toxicity characteristic leaching procedure (TCLP)

AbstractThe toxicity characteristic leaching procedure (TCLP) method was used to analyze the contaminants in the sediment materials of Kaohsiung Harbor as to evaluate the pollution potential associated with the Kaohsiung Harbor. A total of 80 sediment samples were collected at 20 locations and characterized for water content, organic matter (OM), total nitrogen (TN), total phosphorus (TP), and total grease (TG) as well as the leachable and total metals. The results indicated that the leachable metal concentrations were below the low detectable levels for mercury (Hg), lead (Pb), cadmium (Cd), chromium (Cr), and silver (Ag), between 0.005 and 0.281 mg/L, 0.07 and 24.0 mg/L, and 0.013 and 0.221 mg/L for Cu, Zn, and Ni, respectively. The leachable metal concentration at the river mouth vicinity was higher than that at other locations indicating that upstream industrial and domestic wastewater discharges were the main pollutant sources. Results of correlation studies revealed that the OM concentration in the ...

Spatio-temporal variations of water quality in Yuqiao Reservoir Basin, North China

Fuzzy comprehensive assessment and multivariate statistical techniques including cluster analysis, discriminant analysis, principal component analysis, and factor analysis were applied to analyze the water quality status of Yuqiao Reservoir Basin, North China, for assessing its spatio-temporal variations and identifying potential pollution sources. In this paper, we considered data for 14 water quality parameters collected during 1990–2004 at 7 water quality monitoring sites. The results of fuzzy comprehensive assessment revealed that water quality in Yuqiao Reservoir Basin showed a downtrend from 1990 to 2001 with fluctuation, and a slowly upward trend after 2001. The major water quality belonged to Class III and IV. Besides, hierarchical cluster analysis divided 7 monitoring sites into two groups (Group A and B), and 12 months into three periods (low-flow (LF), normal-flow (NF), and high-flow (HF) period). Temp, pH, SS, T-har, DO, NO3-N and TP were identified as significant variables affecting spatial variations, and Temp, pH and NO2-N were identified as significant variables affecting temporal variations by discriminant analysis. Factor analysis identified four latent pollution sources for water quality variations: nutrient pollution, organic pollution, inorganic pollution, and natural pollution. Moreover, for Group A regions, pollution inputs mainly came from domestic wastewater and industrial sewage. For Group B regions, it is more likely that water pollution resulted from the combined effects of domestic wastewater, hospital wastewater, agriculture runoff, and fishpond discharge, as well as the incoming water from upstream.

Satellite data regarding the eutrophication response to human activities in the plateau lake Dianchi in China from 1974 to 2009

Human activities contribute highly to water eutrophication. In this study, the relationship between human activities and water eutrophication in Dianchi Lake in China was characterized using a combination of satellite imaging, sedimentary physicochemical and meteorological data analyses. The heavy eutrophic status and algal bloom in Dianchi Lake were first observed by satellite in 1977 and 1989, respectively. The C/N ratio, an indicator of organic sources in sediments, also showed that the planktonic organic source in the sediment significantly increased beginning in 1989. The land use cover in the Dianchi basin showed that both farm lands and forests, but particularly farmlands, were reduced during the period from 1974 to 2009. The urbanized land area increased from 1974 to 2009, particularly after 2000. The effects of human activities on water eutrophication were expressed by land use cover, population, gross domestic product (GDP; separated into primary, secondary and tertiary industries) and wastewater discharge. For land use cover, farm and urbanized lands were the main sources of water nutrients; forest contributed slightly to these nutrients. For GDP, primary (correlation coefficient=0.94, P<0.001) and tertiary (correlation coefficient=0.95, P<0.001) industries were highly correlated with total nitrogen. Secondary (correlation coefficient=0.95, P<0.001) and tertiary (correlation coefficient=0.96, P<0.001) industries were highly correlated with total phosphorus. The algal bloom area was significantly correlated with wastewater discharge (correlation coefficient=0.78, P<0.005) (except industrial wastewater), which was primarily led by the non-agricultural population, from 2000 to 2009. This study suggests that the protection of water environments requires a comprehensive protection policy in addition to a unilateral protection policy.

Assessment of Mosquitofish (Gambusia affinis) Health Indicators in Relation to Domestic Wastewater Discharges in Suburbs of Houston, USA

Personal care products, pharmaceuticals, and other contaminants of emerging concern (CECs) in domestic wastewater treatment plant (WWTP) effluents can impact aquatic organisms. Health indicators were compared for mosquitofish (Gambusia affinis) collected above and below WWTP discharges from five streams in suburban areas of the Houston metropolitan area, Texas, USA. Specimens were evaluated for reproductive, morphological, and histological indicators. Several indicators revealed significant spatial and temporal variation; however, possibly because of their mobility, fish collected upstream and downstream of wastewater treatment plants did not reveal consistent trends based on the endpoints examined. CEC concentrations in water samples from stream reaches below WWTP discharges were quantified for the first time in the Houston Metropolitan area. The 18 CECs detected in stream water had concentrations lower than values currently reported to impact fish. Future research should examine caged fish at each site and fish collected over longer stream reaches that receive successive discharges from WWTP and stronger CEC gradients.

The long road to improving the water quality of the Western Bug River (Ukraine) – A multi-scale analysis

• We analyse water quality along a river basin and identify relevant pollution sources. • Administrative, spatial and temporal scales have to be equally considered for the analysis. • Wastewater sector is identified as dominant polluter due to deteriorated infrastructure. • River basin management approach has the potential to overcome conflicting scales. • To improve water quality substantial reforms and investments are required. River basin management (RMB) was introduced to combat high levels of water pollution across Ukraine. The Western Bug River provides an example of how water quality is impacted by industrial and domestic wastewater discharges as well as pollution from agriculture and mining activities. The paper draws from a broader interdisciplinary study which aims to outline the sources of pollution within the upper Western Bug River catchment and identify the driving institutional forces behind this enduring environmental problem. The results of this study show that the administrative and spatial scales concerning river catchment management in the Western Bug River basin are not aligned. Furthermore, the temporal scale is often conflicting with the two above mentioned scales. The current political and financial situation of the State, as well as outdated administrative structures hinders effective water governance and results in low water quality. Despite these findings, there is also some evidence that in the longer term the RBM approach could succeed in the Western Bug River, especially if political and legal reforms are properly implemented and enforced.

신도시 개발 후 도시하천의 장래수질 평가

Abstract : Water pollution problems of urban rivers due to the urbanization and industrialization have been the subject of public attention. In particular, considering the fact that the characteristics of water cycle of each basin change dramatically through the development of new towns, a large number of concerns about future water quality have been raised. However, reasonable measures to predict future water quality quantitatively have not been presented by this moment. In this study, by the linkage of annual unit load generation based on long-term monitoring results of the ministry of environment (MOE) to a semi-distributed rainfall runoff model, SWMM (Storm Water Management Model), we proposed a new methodology to estimate future water quality macroscopically and testified it to verify its applicability for the estimation of future water quality of a small watershed at G new town. As a result of the estimation using Y-EMC (Yearly based Event Mean Concentration), future water quality were simulated as BOD 18.7, T-N 16.1 and T-P 0.85 mg/L respectively which could not achieve the grade III of domestic river life guidance and these criteria could be satisfied by the reduction of domestic wastewater discharge load by over 80%. The results of this study are shown to be utilized for one of basic tools to estimate and manage water quality of urban rivers in the course of new town developments.

Tracking anthropogenic influences on the continental shelf of China with sedimentary linear alkylbenzenes (LABs)

Surface sediments collected along the entire continental shelf of China, including Yellow Sea, the East China Sea (ECS) inner shelf and the South China Sea (SCS), were analyzed for linear alkylbenzenes (LABs), from which regional anthropogenic influences on the marine environment were assessed. The occurrence of LABs (5.6–77ng/g; mean: 25ng/g; median: 20ng/g) implied light sewage contamination in coast sediment off China. Specifically, the SCS had higher sedimentary LAB levels than Yellow Sea and the ECS inner shelf, which was mainly related to the intensity of domestic wastewater discharge and marine fishing activities. Values of L/S and C13/C12 (defined in the main text) suggested certain degradation while I/E indicated limited degradation of LABs. Also, additional input sources and congener inter-conversions may have contributed to the inconsistent results for degradation of LABs in offshore sediments. Atmospheric inputs and wastewater discharge from marine fishing vessels predominantly contributed to sedimentary LABs in Yellow Sea and the SCS, while riverine input was mainly responsible for LABs along the ECS inner shelf.

Spatial and seasonal characteristics of river water chemistry in the Taizi River in Northeast China

Anthropogenic activities have led to water quality deterioration in many parts of the world, especially in Northeast China. The current work investigated the spatiotemporal variations of water quality in the Taizi River by multivariate statistical analysis of data from the 67 sampling sites in the mainstream and major tributaries of the river during dry and rainy seasons. One-way analysis of variance indicated that the 20 measured variables (except pH, 5-day biological oxygen demand, permanganate index, and chloride, orthophosphate, and total phosphorus concentrations) showed significant seasonal (p ≤ 0.05) and spatial (p < 0.05) variations among the mainstream and major tributaries of the river. Hierarchical cluster analysis of data from the different seasons classified the mainstream and tributaries of the river into three clusters, namely, less, moderately, and highly polluted clusters. Factor analysis extracted five factors from data in the different seasons, which accounted for the high percentage of the total variance and reflected the integrated characteristics of water chemistry, organic pollution, phosphorous pollution, denitrification effect, and nitrogen pollution. The results indicate that river pollution in Northeast China was mainly from natural and/or anthropogenic sources, e.g., rainfall, domestic wastewater, agricultural runoff, and industrial discharge.

Situation analysis of China's wastewater discharge

Great progress has been made in reducing China’s water pollution after decades of efforts. From the perspective of wastewater discharge, the situation of wastewater discharge since 1985 is analysed in this study, with importance attached to industrial wastewater, including wastewater from township enterprises, and to municipal domestic wastewater. In general, the total wastewater discharge in China is still growing year by year, resulting mainly from the increasing municipal domestic wastewater discharge. Industrial wastewater discharge has been under effective control, with the discharge rate that meets standards being higher than 90%. Take township enterprises as an example, their wastewater discharge and chemical oxygen demand (COD) discharge, which for a time accounted for 21% of the total industrial wastewater discharge and 44.3% of the total industrial COD discharge, respectively, have decreased greatly, after taking a series of measures such as shutting down, stopping run, combination and transferr...

A novel pollution index based on the bioavailability of elements: a study on Anzali wetland bed sediments

In this research, we study on the distribution of several elements in bed sediments of Anzali wetland. Anzali, one of the most important international wetlands, is located on the southern coast of the Caspian Sea in Iran. This wetland receives discharges of domestic, agricultural, and industrial wastewater, which affect the distribution of elements. Our contribution in this study is threefold. First, we measured the total concentration of metals as well as their chemical partitioning and bioavailability in the sediments. Second, we calculated anthropogenic portions of metals in the sediment of this area. The results reveal anthropogenic portion of metals as Mo > Mn > Cd > As > Zn > Hg > Co > Sn > Cu > V > Ag > Ni > Pb > Fe > Cr > Al, respectively. We evaluated the intensity of pollution by using an enrichment factor, the geo-accumulation index and the pollution index. All these indices do not take into consideration the bioavailability of the elements. As our third and most important contribution, we introduced a new formula that takes into account the bioavailability of different elements. In comparison with aforementioned pollution indices, our newly introduced pollution index has a higher Pearson correlation with anthropogenic portion of metals. This high-correlation coefficient shows that our proposed pollution index is an effective indicator for determining the level of pollution, while other indices preserve their own merits.

&lt;b&gt;Effects of intensive fish-farming and domestic wastewater on the periphytic algal community in a tropical coastal lagoon (Juara, Brazil)&lt;/b&gt; - doi: 10.4025/actascibiolsci.v35i3.17094

This study aimed at evaluating the effects of the intensive fish-farming and the domestic wastewater on the structure of the phycoperiphyton community. Three experimental supports containing artificial substrate were assembled in two sampling sites: IF – region with intensive fish-farming and DW – near the domestic wastewater discharge. Samplings were carried out after the 21st, 26th and 31st day of colonization. The abiotic variables evaluated were: transparency, electrical conductivity, pH, turbidity, total suspended solids, alkalinity, dissolved oxygen, water temperature and nutrients. Phycoperiphyton was examined with regard to density, richness, abundance, dominance, diversity and eveness. Nutrients (total nitrogen, nitrate, ammonia nitrogen, orthophosphate and silicate) were different among the sampling sites. Although the total density, richness, diversity and evenness of phycoperiphyton were not affected by the different impacts, the density by class had differences between the sampling sites, with Bacillariophyceae presenting higher density at IF and Cyanophyceae and Coscinodiscophyceae at DW. Four taxa have been associated with the impact by domestic wastewater, and four, to the intensive fish-farming. The density by class of phycoperiphyton was the best attribute to evaluate the effects of human activity.