Source Pollution Management Research Articles

Characteristics and Health Risk Assessment of Trace Elements in Atmospheric PM1 During Autumn and Winter in Qingdao

From November 1,2018 to January 31,2019 (OP2018-2019) and from November 1,2019 to January 20, 2020 (OP2019-2020), PM1 measurement was conducted daily for two consecutive years. The concentration of trace elements in the atmospheric PM1 in Qingdao in autumn and winter was analyzed. The observation period was divided into four air quality levels (Level Ⅰ, Level Ⅱ, Level Ⅲ, and Level Ⅳ), and the characteristics and sources of the concentration of trace elements in PM1 were analyzed. The non-carcinogenic risks (Zn, Pb, Mn, Cu, and V) and carcinogenic risks (As, Cr, Ni, Cd, and Co) of different people with different air quality levels were evaluated. The results showed that the changes in total metal element concentrations were associated with changes in Ca, K, and Al concentrations at different air quality classes during OP2019-2020 compared to those during OP2018-2019 and were more influenced by dust and biomass combustion sources. Compared with that during OP2018-2019, the V concentration in different air quality levels (Level Ⅰ, Level Ⅱ, Level Ⅲ, and Level Ⅳ) during OP2019-2020 decreased by 19.0%, 60.5%, 82.7%, and 77.5%, respectively. This was presumed to be related to the implementation of the Domestic Emission Control Area (DECA) policy for ships, which led to the significant reduction in V concentration due to the change in fuel quality of ships in the waters around Qingdao. The results of the enrichment factor, the ratio method, and the backward trajectory of airflow further indicated that the changes in V concentrations were mainly influenced by the DECA policy. However, after the implementation of the DECA, the V/Ni value as a limit for judging the influence of ship sources in the area required further exploration. The health risk assessment results showed that the risk factor of Mn ranged from 0.07 to 1.22 during OP2018-2019 and OP2019-2020. It was recommended to strengthen the management and control of Mn-containing pollution sources. The lifetime carcinogenic risk (ILCR) value of As and Cd under different air qualities during OP2018-2019 and OP2019-2020 was lower than 10-4 but higher than 10-6, indicating that there was a carcinogenic probability, although it was still at an acceptable level. During OP2018-2019, when the air quality was Ⅳ, the ILCR value of Cr was higher than 10-4, and there was a risk of cancer.

Macroinvertebrates as bio-indicators of water quality in Omubira Stream, in Kakamega County, Kenya

Human-induced environmental stress can impair freshwater ecosystems by destroying them or altering them in negativeways. Laws and ordinances that stress Kenya's water resources' correct management and utilization were prompted by worries about the management of freshwater bodies. Therefore, understanding of the health status of aquatic environments, particularly their biodiversity, is crucial in order to comprehend the status of water quality and limit the rate of pollution in our streams and rivers. Several well-known biological markers of water quality can be used for this. Bio-indicators are species or groups of species that can quickly reveal the abiotic or biotic condition of an environment, show how environmental change has affected a habitat or ecosystem. In many industrialized nations, including those in Europe and North America, macroinvertebrates are widely utilized as bio-indicators and are part of their national and technical standards for water quality monitoring. Their use is still relatively restricted in developing nations like Kenya. Furthermore, the use of aquatic macroinvertebrates as bio-indicators of water quality to assess the condition of aquatic ecosystems is not stressed by Kenyan environmental laws and regulatory bodies. This can be because the nation doesn't have a well-known and established biomonitoring system. However, only a small number of studies have begun utilizing macroinvertebrate species as bio-indicators at this time. A greater comprehension of the macroinvertebrate variety of the Omubira River could help in the stream management due to continued municipal and agricultural activities along this river. As a result, this study examined the use of macroinvertebrates as bio-indicators of river water quality and determined how they reacted to water quality in the various region of the stream.Macroinvertebrates and selected physicochemical variables were sampled monthly in four sites for a period of four months. On each sampling sites at every sampling episode physicochemical variables including temperature, conductivity, salinity, turbidity, pH, dissolved oxygen and percentage saturation oxygen were measured using a Hydrolab Quanta Multi-Probe Meter. A Surber sampler of an area 1200 cm2 and corer sampler were used with catching area of 20.83 cm2 to capture macroinvertebrates. There was a general decrease of Temprature, turbidity, salinity, conductivity and pH from the town area to the forested area. However, dissolved oxygen increased from the town area to forested area. A general variation of macroinvertebrates species from manucipal area to forested area in the river was observed. The highest abundance of Belostomatidae (16.87), Chironomidae (16.77), Naididae (14.07) and Gomphidae (18.67) were found in the manucipal reach of the river. The highest abundance of Elmidae (20.49) and Notonectidae (19.87) were found in the agricultural reach while the highest abundance of Gerridae (10.53), Hydropsychidae (28.65) and Perlidae (33.92) were found at the forested reach. From the diverse makeup of the macroinvertebrates, Omubira stream's water quality can be described as moderately clean. This could be harmful to aquatic life and communities living along, which depends on highly clean water to exist. This study therefore recommends continuious monitoring and proper management of pollution sources into the stream by the pertinent authorities as well as embracing bio-indictors.

River Pollution by Heavy Metals and Associated Impacts on the Adjacent Community, the Case of Holeta and Golli Rivers, Holeta Town, Ethiopia.

This study aimed to determine the level of heavy metals in the Holeta and Golli rivers and their impacts on the community of Holeta town, Ethiopia. Water samples were collected from eight randomly selected locations (4 sites from each river). A questionnaire survey, FGD, and KII were also used. Secondary data were also taken from the nearby health center. The flame atomic absorption spectrometer was used to analyze the samples. Fe, Mn, Ni, Cr, Pb, Cu, Zn, Co, and Cd were the identified heavy metals. The Holeta River contains Fe > Mn > Zn > Ni > Cr > Cu > Pb > Co > Cd, whereas the Golli River contains Fe > Mn > Zn > Ni > Cr > Cu > Pb > Co > Cd. The levels of Fe, Cr, Ni, Fe, and Mn were above the permissible limit of WHO (1984) and USEPA (1992). The primary sources of income for the people who lived in the area were farming and jobs on flower farms. Wastewaters discharged from the surrounding flower farms were the major polluting source (84.3%) of the river. About 84.3% of the surrounding community claimed that wastewaters discharged from the flower farms are the major polluting sources of both rivers. Many of the flower farmworkers (43.9%) have also exposure to toxic insecticides and pesticides used on the farm. About 60% and 20.5% of the workers have frequent severe headaches and skin irritation due to exposure to heavy metals. Generally, both the surrounding community and flower farmworkers are facing significant health and socioeconomic impacts due to the heavy metals joining the rivers. Therefore, effective management of pollution sources and continuous monitoring of the river quality is very imperative to minimize the impacts.

친환경적 유역관리를 위한 토지이용 관리방안 - 평택호 사례를 중심으로 -

The purpose of this study is to propose land-use policy strategies for environmental friendly watershed management for Pyeongtaek Lake. Primary research methods are 1) review of plans related to the land uses around Pyeongtaek Lake, 2) review of concepts about environmental friendly land use methods, 3) examination of relevant cases in South Korea and other countries. After the review of existing plans related to Pyeongtaek Lake and surrounding watershed areas, we found the following: 1) application of growth management strategies for the area undesignated from Pyeongtaek Lake tourism sites, 2) consideration and application of developable areas and incentive-related growth management plan, 3) necessity for management of local run-off and non-point pollution sources for water circulation system in the watershed. Based on the observation we derived the following conclusions: 1) we need land use management strategies especially for residential areas based on Low Impact Development, 2) land use strategies based on the combination of urban planning and institutional tools, 3) application of LID is necessary through incentives and requirement. We advise that due to the limited nature of literature review, further studies from quantitative approaches for environmental friendly land use management strategies are necessary in the future.

Source tracing of potentially toxic elements in soils around a typical coking plant in an industrial area in northern China

Coking plants are a substantial source of potentially toxic elements (PTEs) in soil. In this study, we examined the concentration of PTEs, the soil physicochemical properties, and the Pb isotopes in the soil inside and around a coking plant in an industrial city in northern China. We analyzed the spatial distribution of PTEs and the pollution risk areas by Igeo index, the enrichment factor (EF), and the Nemerow index, and we quantitatively identified the contribution of PTE pollution sources in the soil on a small- and medium-scale (plant and work section). Our results indicated that the Hg concentration inside the plant and the Cd concentration in the agricultural land around the plant were both relatively high. A comprehensive analysis of the soil in the study area was performed using the positive matrix factorization model and Pb isotope (206/207Pb, 208/206Pb) tracing method, based on the MixSIAR model, this analysis indicated that burning coal was the main source of Pb both inside (46.8%) and outside (26.3%) the coking plant. The pollution emission sources with significant influence on the soil outside the coking plant were diesel vehicles (12.5%), gas tanks (12.4%), and coke ovens (11.5%), while the sources inside the plant were quenching sections (11.1%), atmospheric deposition (11.0%), coke oven sections (9.6%), and diesel vehicles (6.1%). The results of PTE pollution risk zoning and Pb isotope tracing indicated that pollution is more serious in the western part of the plant, which is the area where coking and gas production takes place, and the most serious pollution outside the plant is mainly distributed to the southeast. This study provides theoretical and practical data indicating the contribution of industrial enterprises to soil pollution, and will help identify pollution responsibility and the management of pollution sources.

On-line Automatic Monitoring and Control Management of Environmental Pollution Sources

On-line Automatic Monitoring and Control Management of Environmental Pollution Sources

How far climatic parameters associated with air quality induced risk state (AQiRS) during COVID-19 persuaded lockdown in India.

Global temperature rises in response to accumulating greenhouse gases is a well-debated issue in the present time. Historical records show that greenhouse gases positively influence temperature. Lockdown incident has brought an opportunity to justify the relation between greenhouse gas centric air pollutants and climatic variables considering a concise period. The present work has intended to explore the trend of air quality parameters, and air quality induced risk state since pre to during the lockdown period in reference to India and justifies the influence of pollutant parameters on climatic variables. Results showed that after implementation of lockdown, about 70% area experienced air quality improvement during the lockdown. The hazardous area was reduced from 7.52% to 5.17%. The spatial association between air quality components and climatic variables were not found very strong in all the cases. Still, statistically, a significant relation was observed in the case of surface pressure and moisture. From this, it can be stated that pollutant components can control the climatic components. This study recommends that pollution source management could be a partially good step for bringing climatic resilience of a region.

Impact of the COVID-19 lockdown period on surface water quality in the Meriç-Ergene River Basin, Northwest Turkey

The surface water resources in the Meriç-Ergene River Basin, especially Ergene River and Çorlu Stream are among the most polluted rivers in Turkey. Despite the action plans for prevention and control of surface water pollution in the basin, the desired results have not been achieved. However, the implementation of a nationwide lockdown due to the COVID-19 might probably lead to an improvement in the surface water quality. We evaluated the impact of the lockdown on water quality by measuring the levels of physico-chemical variables and metal(loid)s in water samples taken from 25 sampling stations in the basin. BOD, COD, EC, turbidity, TSS and Mn levels did not show significant differences between the pre-lockdown and lockdown periods due to the ongoing domestic wastewater discharges and agricultural activities in the basin during the lockdown period. However, Cr, Ni, Zn, Cu, As, Pb and Cd concentrations decreased considerably during the lockdown. Similarly, heavy metal pollution index and heavy metal evaluation index values showed a significant improvement in water quality of almost all stations during the lockdown period. Also, total hazard index values for children and adults reduced by 67% and 69%, respectively during the lockdown period, while total carcinogenic risk values for As and Cr reduced by 60% and 94%, respectively. The limited operational status of most industrial facilities in the basin during the lockdown reduced the amount of industrial effluents, leading to significant improvement in surface water quality for metal(loid)s. The lockdown has shown that the solution for preservation and sustainability of natural water resources lies in our hands, and the efficient management of pollution sources can prevent surface water pollution at a very rapid pace. Finally, we suggest that water management policy needs to be improved and implemented.

Enterococci Contamination on Edisto Island, South Carolina: Frequency, Sources of Contamination, and Prospects on How to Improve Water Quality

Beach monitoring samples were collected from 18 (14 currently in use) locations on Edisto Island, South Carolina, from 2000 to 2016 to assess patterns of water quality violations (contraventions) indicated by the presence of multiple Enterococcus species, including Enterococcus faecalis and Enterococcus faecium, bacteria used to assess the health of surface waters for contact recreation. Statistical analyses were conducted comparing Enterococci levels and different environmental variables including location, tidal stages, wind direction, and time. Specific focus was placed on temporal and spatial patterns for dates when the bacteria levels exceeded 104 Most Probable Numbers (MPN) per 100 milliliters (ml), which is the Enterococcus single sample maximum (SSM) water quality standard in South Carolina. Results indicated that 2.2% of the samples exceeded the Enterococcus SSM standard and that the majority of these SSM contraventions occurred in September, during periods without significant rainfall but when primarily easterly winds occurred, at or near the time of flooding associated with King Tides (flood tides higher than 7.5 ft). Statistical analysis indicated that wind direction and tidal stage (at or around high tide—¾ flood to ¼ ebb) appeared to have more of an impact on bacterial levels than rainfall, per se. Microbial source tracking using quantitative polymerase chain reaction (qPCR) analysis was conducted and used to identify potential bacterial pollution sources causing Enterococci levels to exceed the SSM. Results indicated that birds and domestic dogs, rather than humans, were the major sources of bacterial pollution. These findings suggested that flooding during King Tides inundated a larger area of the beach-face surface containing bird and dog waste, which resulted in elevated levels of Enterococcus SSM contraventions, primarily on the southern end of the island. These findings are particularly relevant due to the increasing sea-level rise associated with climate change. Changes in population growth on Edisto Island were also analyzed and indicated that permanent population has been increasing at a relatively low rate, while high rates of tourism growth have been observed and may play a factor in observed increases in Enterococcus SSM contraventions. Comparisons of contact recreational water quality with other South Carolina (SC) beaches indicated that Edisto Island (2.2% of Enterococcus SSM contraventions) was third only behind the Grand Strand (10.9%) and Sullivan’s Island (3.9%), both of which have much higher population densities (777–1,300 people/sq. mile) compared to Edisto Island (36 people/sq. mile). These low population densities at Edisto Island and microbial source tracking results further indicate that most pollution sources were from birds and dogs and indicate the important role of coastal flooding associated with climate change. Coastal flooding is continuing to significantly increase as 24.4% of all King Tide flooding events in Charleston, South Carolina, over the past 67 years have occurred from 2019 to 2020. Better management of microbial pollution sources from dogs and birds is essential to prevent further degradation and loss of ecosystem services.

Assessment the effects of physiochemical parameters on water ecological quality using indices based on macro-invertebrates communities in the Karaj and Jajrood Rivers

This is the first study with the greatest number of multimetric indices calculated in Iran to assess water quality at Jajrood and Karaj protected rivers. Given the point that these rivers supply a large portion of Tehran's drinking water, the present study aims at determining ecological quality of these rivers based on a suitable biotic index among these indices. Physicochemical and macro-invertebrate samples were collected with three replications during three consecutive years from 19 stations with a Surber sampler. In the Jajrood River, macroinvertebrates with 6667 abundance belong to 22 families and in the Karaj River, macro-invertebrates with 13,246 abundance belong to 24 families have been identified. The most appropriate time for sampling is in summer because of the existence maximum abundance and diversity of macroinvertebrates. The results of CCA have been shown physicochemical parameters TSS, EC, pH, and BOD have the most effect on the distribution of macroinvertebrates. Among the 16 biotic indices, the FBI index in Karaj River and the BMWP/ASPT index in the Jajrood River are the most reliable indices for assessing the water quality. The results showed that point pollution sources (orchards, restaurants and villages) and nonpoint sources (tourism activities and recreational area) have the most negative impact on the ecosystem of these two rivers. Results of water quality assessment have been shown the changes in ecological quality of water due to human activities; therefore, it is necessary to increase control and management of pollutant sources to improve the water quality of these two rivers.

Analysis of Nitrogen Pollution and Its Pollution Sources in the Muli River Basin

To identify the sources of nitrogen pollutants in the Muli River basin in the Guangdong-Hong Kong-Macao Greater Bay Area, ammonium salt isotope tracer technology, nitrate isotope tracer technology, and a multiple linear mixing model were applied in this study to effectively identify the changes of nitrogen sources in the basin. The results showed that nitrogen pollution in the Muli River basin was serious, and the concentrations of NH4+-N and NO3--N in the confluence were higher than in the two tributaries. In addition, although there was no obvious population residence at the upstream or downstream of the Muli River basin, higher nitrogen pollution still occurred at some sites (Dakengshan tributary and aquiculture area). Qualitative analysis of ammonium salt and nitrate isotopes showed that nitrogen pollution in the Muli River basin mainly came from soil, fertilizer, atmospheric particles, and animal and human excreta. The results of the multiple linear mixing model showed that the main source of nitrogen in the upper reaches of the Dakengshan tributary is atmospheric subsidence, with a contribution rate of about 80%. The average contribution rate of soil organic nitrogen in the upper reaches of the Jilongkeng tributary was 33%, higher than those of the Dakengshan tributary (9%) and Muli River (24%). The contribution rate of sewage and manure to nitrogen pollution was up to 70% in the lower reaches of the Dakengshan tributary, the lower reaches of the Jilongkeng tributary, and the middle and upper reaches of the Muli River. In addition, while all forms of livestock and poultry farming and aquiculture activity were stopped, the contribution rate of sewage and manure in Yangzhiqu was found to be still as high as 56%, which is much higher than that at the Danshui River Dam section in the lower part of the Muli River (3%); this may be due to residual livestock waste in the sediment. This study qualitatively and quantitatively analyzed the nitrogen sources of the Muli River basin, which provids a theoretical basis for pollution source management in the Greater Bay Area.

COVID-19 pandemic persuaded lockdown effects on environment over stone quarrying and crushing areas

Stone quarrying and crushing spits huge stone dust to the environment and causes threats to ecosystem components as well as human health. Imposing emergency lockdown to stop infection of COVID 19 virus on 24.03.2020 in India has created economic crisis but it has facilitated environment to restore its quality. Global scale study has already proved the qualitative improvement of air quality but its possible impact at regional level is not investigated yet. Middle catchment of Dwarka river basin of Eastern India is well known for stone quarrying and crushing and therefore the region is highly polluted. The present study has attempted to explore the impact of forced lockdown on environmental components like Particulate matter (PM) 10, Land surface temperature (LST), river water quality, noise using image and field derived data in pre and during lockdown periods. Result clearly exhibits that Maximum PM10 concentration was 189 to 278 μg/m3 in pre lockdown period and it now ranges from 50 to 60 μg/m3 after 18 days of the commencement of lockdown in selected four stone crushing clusters. LST is reduced by 3–5 °C, noise level is dropped to <65dBA which was above 85dBA in stone crusher dominated areas in pre lockdown period. Adjacent river water is qualitatively improved due to stoppage of dust release to the river. For instance, total dissolve solid (TDS) level in river water adjacent to crushing unit is attenuated by almost two times. When entire world is worried about the appropriate policies for abating environmental pollution, this emergency lockdown shows an absolute way i.e. pollution source management may restore environment and ecosystem with very rapid rate.

Assessing Cadmium and Chromium Concentrations in Drinking Water to Predict Health Risk in Malaysia.

Although toxic Cd (cadmium) and Cr (chromium) in the aquatic environment are mainly from natural sources, human activities have increased their concentrations. Several studies have reported higher concentrations of Cd and Cr in the aquatic environment of Malaysia; however, the association between metal ingestion via drinking water and human health risk has not been established. This study collected water samples from four stages of the drinking water supply chain at Langat River Basin, Malaysia in 2015 to analyze the samples by inductivity coupled plasma mass spectrometry. Mean concentrations of Cd and Cr and the time-series river data (2004–2014) of these metals were significantly within the safe limit of drinking water quality standard proposed by the Ministry of Health Malaysia and the World Health Organization. Hazard quotient (HQ) and lifetime cancer risk (LCR) values of Cd and Cr in 2015 and 2020 also indicate no significant human health risk of its ingestion via drinking water. Additionally, management of pollution sources in the Langat Basin from 2004 to 2015 decreased Cr concentration in 2020 on the basis of autoregression moving average. Although Cd and Cr concentrations were found to be within the safe limits at Langat Basin, high concentrations of these metals have been found in household tap water, especially due to the contamination in the water distribution pipeline. Therefore, a two-layer water filtration system should be introduced in the basin to achieve the United Nations Sustainable Development Goals (SDGs) 2030 agenda of a better and more sustainable future for all, especially via SDG 6 of supplying safe drinking water at the household level.

Spatial Distribution, Spectral Characteristics, and Sources Analysis of Dissolved Organic Matter from Baiyangdian Lake in Xiong'an New District During the Winter Freezing Period

Based on excitation emission matrix spectroscopy (EEMs) technology combined with parallel factor analysis (PARAFAC) and ultraviolet-visible (UV-vis) spectra, we analyze the spatial distribution, spectral characteristics, and sources of dissolved organic matter (DOM) in Baiyangdian Lake, China, during a winter freezing period. Results showed that the UV-vis absorption spectrum of DOM had no obvious characteristic peak, and that the variation coefficient of absorption exhibited a significant difference (P<0.05) among different districts of Baiyangdian Lake, but that there was no significant difference between the surface and bottom waters. The changes of E3/E4, E2/E3, and SR showed that DOM had low humic and autochthonous characteristics. Two protein-like substances (C1 and C2) and one humic-like substance (C3) were identified by PARAFAC, with a significant correlation (P<0.001) being found between C1 and C3, and C2 and C3. The total DOM fluorescence intensity and the fluorescence intensity of each component exhibited significant differences (P<0.01) in the distribution among the different districts of Baiyangdian Lake, with the maximum value being associated with a sample from the Tanghe River and the minimum value being associated with a sample from Shaochedian. Moreover, the sum of C1+C2 accounted for the major proportion of DOM. DOM exhibited a strong autochthonous characteristic based on the values of BIX, FI, and HIX. Principle component analysis (PCA) and Adonis analysis showed that the spectral characteristics of DOM exhibited a significant difference (P<0.05) among the different districts. C1, C2, and C3 were significantly correlated (P<0.001) with DOM indices (HIX, BIX, Fn280, and Fn355) and water quality parameters[total nitrogen (TN), permanganate index, and total dissolved phosphorus (TDP)] based on multiple linear regression. Our results contribute to previous investigations and provide findings that can assist in the future management and control of organic carbon pollution sources to Baiyangdian Lake.

Determination and Analysis of polycyclic aromatic hydrocarbons (PAHs) in Building Dust Fine particles (PM2.5)

Based on construction of dust particles extraction of polycyclic aromatic hydrocarbons in the optimized analysis, to determine the optimal experimental conditions of ultrasonic extraction of polycyclic aromatic hydrocarbons; Determination of polycyclic aromatic hydrocarbons are normalized concentration analysis, Phenanthrene (PhA) was the highest, accounting for 29.1% of the total PAHs, followed by Naphthalene (NaP) 18.9%, Benzo[b] fluorathene (BbF) 13.1%, Pyrene (Pyr) 8.2%; building the dust PM2.5 fine particles of polycyclic aromatic hydrocarbons the source component spectrum, provide analysis data for the control and management of pollution sources.

Spatiotemporal Distribution of Algae and Characteristics of Algal Abundance in Lake Okjung, Korea

Objectives The objective of this study was to identify the water quality parameters and environmental factors that control the growth and distribution of phytoplankton in Lake Okjung by analyzing water quality and meteorological data using various statistical analysis methods. Methods Water samples collected from the lake between May and November, 2017 were analyzed for various water quality parameters following the Standard Methods for Water Quality Analysis. Identification and quantification of phytoplankton species from the lake were conducted manually under the microscope. Meteorological data of the lake watershed were also collected and analyzed in combination with water quality and phytoplankton data using various statistical analysis methods. Correlation analysis and multivariable statistical methods were applied to identify the parameters that influenced the distribution of phytoplankton in the lake. Results and Discussion While the concentration of particulate matter was elevated in July and August presumably due to concentrated precipitation in the summer, total phosphorus concentration appeared to be controlled by fertilizer application associated with agricultural activities in the area, which was evidenced by the higher concentrations in May and September. Comparison of total nitrogen and total phosphorus data indicated that 76 samples out of 81 showed N/P ratios higher than 17 indicating that Lake Okjung was in a phosphorus-limited condition during the study period. Calculation of Korea Trophic State Index (TSIko) showed that the lake is generally in mesotrophic or oligotrophic conditions. The phytoplankton community was dominated by chlorophyte (50%), diatoms (25%), and cyanobacteria (9.6%) in terms of the number of species, and the highest cell concentrations were observed in the area where Oknyeodong-cheon, one of the tributaries, joins the lake. Principal component analysis identified 4 components that explained 74.6% of the total variance of the data with PC1, PC2, PC3, and PC4 explaining 40.4%, 14.9%, 11.3%, and 8.0%, respectively. These components were attributed to biogeochemical change induced by growth of phytoplankton in response to meteorological fluctuation, inflow of phosphorus from regional agricultural activities and its impact on phytoplankton growth, physical change of the lake water caused by concentrated precipitation in the summer, and environmental changes causing growth of cyanobacteria in the summer. Conclusions Lake Okjung was in P-limited conditions and the distribution of phytoplankton appeared to be controlled by seasonal variation of meteorological conditions and input of nutrients, especially phosphorus from the 2 main tributaries, Oknyeodong-cheon and Seomjin river. Although seasonal distribution of precipitation did not cause a significant increase in phosphorus concentration in the lake, proper management of pollution sources in the watershed of the 2 tributaries seem to be important in controlling algal bloom formation as severely concentrated rainfall in the area has the potential to produce eutrophic conditions in the lake and trigger explosive growth of phytoplankton. Key words: Lake Okjung, Algae, Statistical Analysis, Nutrients, Seomjin River Dam

Pollutant source analysis and tempo-spatial analysis of pollutant discharge intensity in a transboundary river basin.

From the perspective of river basin refined management and pollution control of water bodies, a transboundary river basin and its regional pollutant sources are identified and the typical status of discharging processes of different pollutant sources are screened. Then organic connection which can comprehensively reflect and dynamically characterize the discharge of transboundary water pollutants is constructed. In addition, the integrated prediction (IP) model of the transboundary river basin and its regional water pollutants discharge is established. Finally, the dynamic simulation of typical status characteristics of the transboundary river basin and its regional pollutant sources discharge as well as the tempo-spatial changing pattern of pollutant discharge intensity is conducted in this paper. This paper selected the Songhua River basin as an example where planting, industry, household (urban living and rural living), and livestock and poultry are the main pollutant sources. The dynamic simulation of water pollution discharge in Songhua River basin during the 13th Five-year Plan and its tempo-spatial changing trend analysis are conducted by employing the established IP model of transboundary river basin water pollution discharge. The results show that during the 13th Five-year Plan, through comprehensive management and control of pollutant sources in Songhua River basin, the discharge amounts of different pollutant sources (planting, industry, household, livestock, and poultry) present an overall decreasing trend and the main pollutants discharge intensity decreases significantly year by year. It is demonstrated that pollution discharge in Songhua River basin is controlled effectively.

Water Quality Improvement Plans of Daeho Reservoir based on the Analysis of Watershed Characteristics and Water Quality Modelling

For effective improvement of water quality in Daeho reservoir, this study implemented various analyses including the tributary water quality and flowrate monitoring, analysis of water quality in agricultural drainage, Daeho reservoir and influent from Sapgyo reservoir, pollutants content of sediment, and pollutant discharge characteristic in Daeho reservoir watershed. The water quality of tributaries in Daeho reservoir watershed was good, but due to the drought, the water quality of Daeho reservoir exceeded the class IV of water environment standard in reservoir because the water from Sapgyo reservoir was introduced into the Daeho reservoir. The main pollution sources in the Daeho reservoir watershed were population and livestock. Careful management of livestock pollution sources should be needed because the pollutants content of sediment, which located in spraying area of liquid livestock manure in Daeho reservoir reclaimed land, were high. The water quality of influent from Sapgyo reservoir should be preferentially improved for improving the water quality in Daeho reservoir. As the evaluation results of water quality in Daeho reservoir for the effect of water quality improvement using water quality model, it was found that the water quality in Daheo reservoir due to the biological and chemical treatment of forty percent of the incoming water from Sapgyo reservoir would be predicted satisfaction of the class IV of water environment standard in reservoir. Key words: Daeho Reservoir, Sapgyo Reservoir, Drought, Watershed Characteristic, Water Quality Modelling, Water Quality Improvement Plan

Dealing with reservoir eutrophication in a trans-boundary river

Article 21 of the United Nation 1997 Convention is related to the protection of water resource quality in non-navigable border rivers. Based on this article, the countries located in the border catchment are prohibited from the actions which contaminate the water sources and jeopardize the health of residents. Further, upon the request of one of the beneficiaries, a common standard, integrated monitoring program and planning to reduce non-point and point pollution sources should be developed. In spite of this law, experience has shown that the management of pollution sources, especially non-point resources in border basins, would be very complicated and time-consuming. Selective withdrawal and discharge of contaminated water from lower level of the dam are regarded as one of the effective ways to optimize the eutrophication condition of dam reservoirs in downstream of border basins. The present study aimed to develop an optimization model to improve reservoir water quality and protect water quality of downstream. This method was employed in Dousti dam located on the river of Harirud. Salma dam construction and agricultural development in Afghanistan strengthen the eutrophication condition of the Dousti dam reservoir. The results showed that reservoir conditions in the status quo were Mesotrophic, which convert to the acute conditions of Eutrophic due to the upstream development. In the case of discharging a percentage of downstream need from the reservoir bottom outlet, based on the results of the optimization model, about 30% of the dissolved oxygen is improved.

A Study on the Management of Nonpoint Pollution Source by Precipitation Monitoring by Tributary in Gumho River

In this study, peak concentration was calculated using long - term monitoring results in order to establish nonpoint pollution source management plan for each station. Based on the estimated peak water concentration, the non - point pollution source management method was derived through comparison analysis with various evaluation factors related to runoff.The 113 monitoring results of the Gumho River watershed were statistically analyzed. The number of dry days in the monitoring point was ranged from 1.0 to 14.0 days in each region. Total precipitation was 88.7 ㎜ upstream, 101.3 ㎜ tributary, and 103.1 ㎜ downstream. As a result of analysis of EMCs up to the average peak water quality concentration by pollutant item, BOD was highest in March and April, COD in April, SS in April and August, T-N in April and T-P in August. The peak EMCs of the pollutant up to the average peak pollutant concentration by the monitoring point was high in April - August in the main stream of the Gumho River and between spring and summer in March - August in the tributary. Statistical analysis was conducted using long - term monitoring data, and a non - point pollution source management plan was proposed based on the results of the nationwide pollution source analysis for the target watershed. By analyzing the pollutant ratio by watershed, we can select the main pollutant source and present the nonpoint pollution sources reduction technique suitable for the reduction of the pollutant source, so that it can be used as the basic data for establishing non - point pollutant management plan for the target watershed. Keywords: Nonpoint Source, Tributary, Basin, Management Methods