Licun River Research Articles

A new freshwater species Achnanthes licunese sp. nov. (Achnanthaceae, Bacillariophyta) from pebbles of Licun River, Shandong Province, China

A new freshwater diatom species, Achnanthes licunese sp. nov., was found on pebble samples collected from Licun River in Shandong Province, China. The various taxonomic characteristics of Achnanthes licunese sp. nov. is observed under light and scanning electron microscope. The living cells of A. licunese sp. nov. possesses two chloroplasts. Its valves exhibit a linear to linear-lanceolate outline, slightly constricted in the middle part, with uniseriate striae. The central area of the raphid valves is expanded into a linear and thickened stauros, and the raphe is filiform. On the araphid valves, there is no central area, and the axial area (sternum) is located in the valve margin. The valve of the A. licunese sp. nov. possesses the marginal spines, but no marginal ridge and terminal orbiculi. By comparing the new species with similar Achnanthes species, A. licunese sp. nov. was confirmed to be sufficiently different regarding valve size, striae density, and the presence of marginal spines. The discovery of this species increases the diversity of freshwater diatoms.

Water quality characteristics and ecological risk evaluation of a landscaped river replenished by three reclaimed water sources in Qingdao, China.

The water crisis may be solved by utilizing reclaimed water. Three reclaimed water sources have restored the lower sections of the Licun River, forming a landscaped river. In this paper, the river's water quality was monitored for a year, and the ecological concerns were analyzed using luminescent bacteria, chlorella, and zebrafish. The results indicated that although basic water quality indicators like COD and ammonia fluctuated along the river, the classification of water quality was primarily affected by factors such as flow rate and water depth. Under experimental conditions, the toxic inhibitory effect of river water on luminescent bacteria, chlorella, and zebrafish was related to the treatment process of reclaimed water. It was found that the reclaimed water produced by the MBR, along with the UV disinfection process, showed no detectable toxicity. In contrast, the MBBR process, when combined with coagulation, sedimentation, filtration, ozonation, and chlorination, seemed to be the source of this toxicity. Along the river, the results of water quality assessments and ecological risk assessments were different, indicating that both should be conducted to evaluate rivers replenished with reclaimed water.

Aquatic ecological risk assessment of imidacloprid and thiacloprid in an urban river of Qingdao, China

Imidacloprid and thiacloprid, two neonicotinoid insecticides that are extensively used in urban areas, are potentially toxic to non-target aquatic organisms. In this study, the concentrations of imidacloprid and thiacloprid in surface runoff after rainfall were 20.79–43.77 ng/L and 25.13–63.84 ng/L, respectively, whereas the levels for the Licun River were 10.78–41.70 ng/L and 2.66–39.68 ng/L, respectively. The acute and chronic criteria for imidacloprid and thiacloprid are 0.865, 0.006, 0.83, and 0.012 μg/L, respectively. Tiered ecological risk assessments revealed the chronic ecological risks of these micropollutants to local aquatic species. There was a moderate chronic toxicity risk associated with imidacloprid and thiacloprid in the Licun River, and the joint probability curves showed a probability of chronic ecological risk to 5 % of the aquatic organisms at 68 %–97 %. The results provide evidence of urban surface runoff transporting micropollutants from surface into rivers and estuaries, highlighting the ecological risks to aquatic ecosystems.

Load quantification and effect evaluation of urban non-point source pollution in the Licun River based on SWAT model.

With the gradual control of point source pollution, the impact of urban nonpoint source pollution on river water quality is becoming more prominent. Regarding the current problem that nonpoint source pollution loads in urban basins are difficult to quantify and the impact on water quality is difficult to analyze, the Licun River basin in Qingdao was selected as the research object. Through the field survey and surface accumulation sampling analysis of the basin, the evaluation model of urban nonpoint source pollution was constructed by revising the land type data of the basin and the urban database of the SWAT model. The results showed that concentration of nitrate in precipitation was most sensitive to the simulation of nitrogen loading; organic P in baseflow was most sensitive to the simulation of phosphorus loading. The Nash-Sutcliffe efficiency coefficient (ENS) and the coefficients of determination (R2) of the SWAT model for runoff, total phosphorus (TP), and total nitrogen (TN) in the simulation validation period meet the model requirements,indicating a good model fit. In addition, the spatial and temporal distribution characteristics of urban nonpoint source pollution of TN and TP in 2021 were analyzed. In July, rainfall-runoff from the Licun River basin was the most polluted.

Influence of Human Activity on Hg Transportation

Hg pollutes the environment, living organisms, and humans; hence, studying Hg content is essential for human health security. Using the dataset in May, September, and October, the Hg content, horizontal distribution, sources and transportation paths in the waters of Jiaozhou Bay were easily determined. These results indicate that the Hg content changing range in the waters in May, September and October was 0.015-0.150 μg/L, corresponding to the national seawater quality standards of Class I and Class II. The Hg content in the water body mainly arises from two sources, the transportation of rivers and offshore ocean currents. It from rivers' offshore ocean currents was 0.019-0.150 μg/L and 0.020 μg/L, respectively. Among them, the transportation of rivers includes the transportation of Haibo River, Licun River and Loushan River. So, a model block diagram has been built to unveil Hg contents and its different paths during the transportation to Jiaozhou Bay. Thus, it becomes easy to quantitively determine the migration process of Hg content through human activities to the ocean and rivers. Hg's different paths and contents reveal four rules for entering Jiaozhou Bay. In May, the offshore ocean currents and Haibo River did not affect by Hg pollution. In September, the Laoshan River was not polluted by it. In October, the Licun River was not, while the Haibo River exhibited light Hg pollution. When the Hg content transported by rivers was relatively low, it by offshore ocean currents became visible. From May to October, three rivers were transporting Hg content. Hg mildly polluted only one river in October, depicting that human activity is a key concern for environmental protection. It discharged by humans to land was relatively low, meanwhile only once was river transportation slightly polluted by it.

Water quality variation of a typical urban landscape river replenished with reclaimed water

Replenishing landscape water with reclaimed water has been an effective way to alleviate urban water shortage. In order to investigate the variation of water quality along the pipeline and flow direction in a typical urban landscape river replenished with reclaimed water, relevant water quality indexes were consecutively monitored for 8 months. Concentrations of chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) all showed a downward trend along the flow direction in reclaimed water effluent pipeline. However, values of turbidity, COD, and chlorophyll a (Chla) were decreased significantly, while concentrations of TN and TP were increased in the mixed area of reclaimed water and river. Furthermore, along Licun River, an upward trend of COD and ammonia-nitrogen (NH4+-N) was observed in summer, while in other seasons, a falling first and then rising trend of COD concentration appeared. The concentration of NH4+-N randomly fluctuated between 0.08 ​mg/L to 2.05 ​mg/L among all seasons, and TN and nitrate-nitrogen (NO3−-N) were below 15 ​mg/L with a downward first and then upward trend in each season. The concentration of TP showed a slightly upward trend (ranging from 0.08 ​mg/L to 0.57 ​mg/L) and Chla was at a relatively low level (0 – 46.32 ​μg/L). The correlation analysis revealed that light intensity, nitrogen and phosphorus were the influential factors of algae growth in river. In addition, the biomass of emergent plants and submerged plants was increased after replenishing with reclaimed water, playing a vital role in the remediation of urban landscape river.

Ecological environment response of benthic foraminifera to heavy metals and human engineering: A case study from Jiaozhou Bay, China

The estuary and coastal zone are the key areas for socio-economic development, and they are also the important channels for pollutants transported to the sea. The construction of the Jiaozhou Bay Bridge changed the hydrodynamic condition of the bay, which made the self-purification capacity of the bay weakened and the pollution in the estuary and adjacent coastal zone become more serious. In this study, 55 surface sediment samples were collected from the three seriously polluted estuaries and the adjacent coastal zone of Jiaozhou Bay to comprehensively study how the benthic foraminifera response to heavy metal pollution and human engineering, and to assess the ecological risks of the bay. A total of 80 species, belonging to 42 genera, were identified in this study. The results showed that Cu, Pb, Cr, Hg, Zn, and As had low to median ecological risks in the study area which would definitely affect the ecological system. The construction of the Jiaozhou Bay Bridge has resulted in pollutants accumulated at the river mouth of Loushan River, which has adverse effects on the survival and growth of benthic foraminifera. The lowest population density and diversity as well as the highest FAI (Foraminiferal Abnormality Index) and FMI (Foraminiferal Monitoring Index) occurred at Loushan River Estuary which indicated that the ecological environment of the northeastern part of Jiaozhou Bay (Loushan River Estuary) had been seriously damaged. Licun River and Haipo River estuaries and the adjacent coastal zone were slightly polluted and had low ecological risk. As a consequence, it suggested that the supervision of industrial and domestic waste discharge and the protection of the ecological environment in northeast Jiaozhou Bay should be paid more attention.© 2022 China Geology Editorial Office.

Pollution Contribution Response in Governance and Potential Pollution Factors in Licun River

The development of the city results in deterioration of the water quality of the Licun River. As a result, years of governance have been conducted to improve its water quality. In order to clarify the response changes of water quality in the water governance, the governance process is divided into three stages (2000–2007, 2008–2016, 2017–2020) according to different priorities. Spearman’s rank correlation coefficient and the comprehensive pollution index are applied to analyze the variation of water quality response at various stages. In addition, the main pollution contributions with the governance changes were obtained. It is concluded that flood control and incomplete river pollution interception have a limited effect on water quality improvement, with NH3-N (ammonia nitrogen) and COD (chemical oxygen demand) being the main pollution contributions at the first stage. At the second stage, the point source control and sewage treatment facilities significantly improve water quality, and the main pollution contributions are NH3-N and TP (total phosphorus). At the third stage, sewage treatment facilities and supporting pipelines are improved, water sources are replenished, and the main pollution contribution is TN (total nitrogen). For further treatment, the factors affecting pollution are analyzed, including the contradiction of sewage system, point source pollution caused by pipe network problems, shortage of water resources, sludge pollution, and non-point source pollution.

Water quality change and pollution source accounting of Licun River under long-term governance

Urbanization and human activities have exerted a tremendous adverse influence on the water quality of the Licun River, Qingdao, China. In order to restore the water quality, a succession of measures have been carried out since 1996, mainly encompassing flood controlling, sewage intercepting and watercourse greening (before 2007), watercourse and point source control based on administrative region (2008–2017), as well as the comprehensive governance based on river basin (after 2018). In 2019, the amount of discharged industrial wastewater, chemical oxygen demand, and ammonia nitrogen decreased by 53.91%, 87.75% and 89.88%, respectively, compared with 2000. Such results indicate that continuous governance has achieved a quantitative effect, and that industrial discharge is not the main pollution source. In the present work, the Spearman rank correlation coefficient and river comprehensive pollution index methods were used to analyze the change trend of main pollutants. The water quality was improved continuously, and the reduction of total phosphorus and ammonia nitrogen was the key to upgrading water quality. Afterward, the emission of pollution sources was accounted for from viewpoints of the point source, non-point source and sludge. Finally, suggestions were put forward to improve the water quality of the Licun River and provide some reference for the urban river management in northern China.

Pollution status, influencing factors and environmental risks of neonicotinoids, fipronil and its metabolites in a typical semi-closed bay in China

The occurrence, spatiotemporal variations, influence factors and environmental risks of eight common neonicotinoids (NEOs), fipronil, and three fipronil metabolites (fipronil and its metabolites are collectively referred to as FIPs) in different seasons from the estuary to the inner area of Jiaozhou Bay, China were comprehensively investigated. First- and second-generation NEOs were found to be the predominant pesticides in this area. The average contents of ∑NEOs and ∑FIPs from the estuary to the inner bay decreased from 12.99 ng/L to 0.82 ng/L and from 1.10 ng/L to 0.17 ng/L, respectively. NEO and FIP concentrations were higher in summer and autumn. High ∑NEO content is distributed in main inflow rivers, such as Dagu River and Licun River, which are influenced by pesticide application. NEO concentrations in all rivers were high upstream and low downstream because of the influence of heavy rainfall and seawater dilution in summer. NEO concentrations were high along the coast and low at the mouth and center of Jiaozhou Bay in summer and autumn and evenly distributed in winter and spring. Temperature has a great influence on most NEOs and FIPs owing to its effect on their degradation. Nitrogen-containing nutrients have an important influence on the distribution of fipronil and acetamiprid, which may be due to the activity of nitrogen-containing functional groups in their structure. Only Licun River, Dagu River and Haibo river sewage treatment plant in summer posed a certain risk of chronic toxicity for NEOs using the new threshold established by the species sensitive distribution (SSD) method for Chinese native aquatic lives. These findings should arouse people's attention.

Mechanism of Cd Content Migration in Sea and Land

based on the survey data of Cd content in Jiaozhou Bay in May, August and October of 1992, the paper studies the process of ocean current transport and the source of Cd content in Jiaozhou Bay. The spatial variation of Cd content from source transport in May, August and October is shown according to Dongfang Yang’s matter content migration rule, which is revealed with the model block diagram. The location, size, type and time scale of source of Cd content transport are also determined. There were three main sources of Cd content in Jiaozhou Bay, from run-off transport, river transport and main sea current transport. Rivers carried Cd content in excess of 0.96μg/L over the year, slightly polluting land and rivers. In addition, Cd content in run-off and main sea current was greater than 1.10μg/L, which means the whole land and ocean were slightly polluted by Cd content. Among rivers flowing into Jiaozhou Bay, there are four major rivers which carried Cd content into the waters of Jiaozhou Bay: Haibo River, Licun River, Loushan River and Dagu River. According to Cd content in the river, from high to low was: Dagu River > Licun River > Loushan River > Haibo River. The Cd content transport time scale of Licun River, Loushan River and Dagu River was the same, while that of Haibo River was shorter. The mechanism of land transport and sea transport is put forward by authors, and the mechanism of alternating migration of Cd content between land and sea is revealed. In May, the land began transporting large quantities of Cd into the sea; from May to August, the land transported Cd content to the sea for three months; In August, the transport from land to sea ended, and the main sea current began to transport Cd content in large quantities; from August to October, the main sea current transported Cd content to the ocean for two months; In October, transport of the main sea current ended, and rivers began to carry Cd to the ocean again. The Cd content transported by northern run-off in May was 1.10μg/L and the Cd content transported by main sea current in August was 1.11μg/L, which further confirmed the authors’ theory of matter uniformity. It can be seen that the Cd content transported by land and by sea was the same. Thus land and sea had the consistency of matter content.

Surface Distribution and Sources of Pb content in the ocean current of Jiaozhou Bay

According to the data on the investigation of Jiaozhou Bay in May, August and October, 1992, the Pb content and the horizontal distribution in the surface of Jiaozhou Bay were studied. The results show that in May, in the waters of Jiaozhou Bay, there were three Pb high content sources - open ocean current, ships and wharf, and Licun River. The open ocean current entered Jiaozhou Bay from the bay outside into the bay inside through the bay mouth with a high content of Pb. The Pb content in the mouth of the bay was 20.79 μg/L. In the bay, the ocean current moved forward the shore of the northeast and reached southeast waters of the bay, transporting 5.54 μg/L Pb content. Then, the ocean current continued to move along the nearshore to the northeast and reached the eastern nearshore waters of Jiaozhou Bay. Here, Pb content was transported via ships and wharf and was 16.34 μg/L. After that, the ocean current continued to move along the nearshore to the northeast and reached the waters in the northeast of the bay, with the Pb content 7.09 μg/L. The ocean current continued to move along the nearshore to the northeast and got the coastal waters near the mouth of the Licun River. Here, Pb content was transported via the Licun River and the Pb content was 37.90 μg/L. Afterwards, the ocean current continued to move along the shore to the northeast and reached the waters in the northeast of the bay, carrying 18.27 μg/L Pb content. Then, the ocean current turned westward along the near-shore direction and got the northern waters of the bay, where the Pb content transported via ocean current was 13.72 μg/L. The ocean current continued to run along the shore to the west and got to the westernmost waters in the northwest of the bay. The Pb content transported via the ocean current was 12.84 μg/L. After that, the ocean current turned southward along the near-shore and reached the waters in the southwest of the bay transporting 8.62 μg/L Pb content. At this moment, a low Pb content area of 7.37 μg/L appeared in the central waters of Jiaozhou Bay.

The land surface mildly contaminated by Hg

The Hg content in the waters of Jiaozhou Bay was within 0.010-0.060μg/L in May, September and October 1993, which conforms to the seawater quality standards of Class I and II. It indicates that in the entire waters of Jiaozhou Bay, there were some water areas that did not get contaminated by Hg while some areas got mild contamination by Hg in May, September and October. In May, the variation range of Hg content in the waters of Jiaozhou Bay was 0.010-0.046μg/L. In September, it ranged within 0.007-0.011μg/L. And in October, the content of Hg detected in the waters of Jiaozhou Bay was 0.060μg/L. There were three sources to transport Hg content, open sea currents, Licun river and the surface runoff. The Hg content from the transportation of open sea currents was 0.046μg/L, from the Licun river was 0.011μg/L and from the surface runoff was 0.060μg/L. This paper builds a model block diagram to present the different paths and Hg contents that were input in the Jiaozhou Bay. In May, the open sea currents did not get any contamination of Hg; in August, the Licun river did not get any contamination of Hg as well; while in September, the surface runoff was mildly contaminated by Hg. The author concluded two points about the migration of Hg content: 1) Human activities discharge Hg to the land so that the Hg content could directly run to the ocean through the surface runoff. As the Hg content transported by surface runoff was relatively high, it resulted that the nearshore waters got mild contamination of Hg content. On the other hand, the surface runoff transported Hg to rivers, resulting relatively low content of Hg. Then rivers delivered the Hg content to nearshore waters, leading to a non-contaminated condition of rivers. 2) Human activities input Hg content to the ocean in a long period, resulting the increase of Hg content in the ocean. As the accumulation of Hg content in the ocean, the ocean got close to the mild contamination status.

Ecological environment response of benthic foraminifera to heavy metals and human engineering: A case study from Jiaozhou Bay, China

The estuary and coastal zone are the key areas for socio-economic development, and they are also the important channels for pollutants transported to the sea. The construction of the Jiaozhou Bay Bridge changed the hydrodynamic condition of the bay, which made the self-purification capacity of the bay weakened and the pollution in the estuary and adjacent coastal zone become more serious. In this study, 55 surface sediment samples were collected from the three seriously polluted estuaries and the adjacent coastal zone of Jiaozhou Bay to comprehensively study how the benthic foraminifera response to heavy metal pollution and human engineering, and to assess the ecological risks of the bay. A total of 80 species, belonging to 42 genera, were identified in this study. The results showed that Cu, Pb, Cr, Hg, Zn, and As had low to median ecological risks in the study area which would definitely affect the ecological system. The construction of the Jiaozhou Bay Bridge has resulted in pollutants accumulated at the river mouth of Loushan River, which has adverse effects on the survival and growth of benthic foraminifera. The lowest population density and diversity as well as the highest FAI (Foraminiferal Abnormality Index) and FMI (Foraminiferal Monitoring Index) occurred at Loushan River Estuary which indicated that the ecological environment of the northeastern part of Jiaozhou Bay (Loushan River Estuary) had been seriously damaged. Licun River and Haipo River estuaries and the adjacent coastal zone were slightly polluted and had low ecological risk. As a consequence, it suggested that the supervision of industrial and domestic waste discharge and the protection of the ecological environment in northeast Jiaozhou Bay should be paid more attention.© 2022 China Geology Editorial Office.

Microalgal Cultivation in Secondary Effluents: Enhancement of Algal Biomass, Nutrient Removal, and Lipid Productivity

The growth performance, nutrient removal, lipid accumulation and morphological changes of Cyanobacterium aponinum OUC1 and Scenedesmus obliquus which were cultured in secondary effluents from two wastewater treatment plants: Tuandao Wastewater Treatment Plant (ETD) and Licun River Wastewater Treatment Plant (ELR) were investigated. The results showed that both C. aponinum OUC1 and S. obliquus have superior growth performances in both undiluted effluents, while the better of them was that in ETD effluent, with cell densities of C. aponinum OUC1 and S. obliquus increased by 159% and 66% over that of BG11 (control), respectively. Regarding nutrient removal, S. obliquus could completely remove inorganic phosphorus, and decrease ammonia nitrogen in ETD effluent by 81%. In addition, both C. aponinum OUC1 and S. obliquus cultivated in ETD exhibited extraordinary potential for biofuel production, increasing lipid productivities by 133% and 89% of that cultivated in ELR, respectively. As to ultrastructural changes, the differences in the lipoidal globules and glycogen granules of S. obliquus and C. aponinum OUC1 among the ETD and ELR treatments were mostly related to phosphorus limitations. The findings from this research reveal the probability using the secondary effluents as cultivation media to enhance algal biomass, nutrient removal and lipid productivity.

The Consistency of the Cd Content in Lands and Oceans

Based on the data from May, August, and October 1992, the Cd content in the Jiaozhou Bay waters varied from 0.11 to 1.53μg/L, up to the water quality standards of Class I and II seawater. This indicates that the water quality of the entire bay was slightly or not polluted by Cd during this period. In May, the variation of the Cd content in the bay ranged from 0.23 to1.53μg/L, more specifically, the Cd content reached a relatively high level of 1.00-1.53μg/L in the offshore waters near the estuary of Dagu River, Loushan River, Licun River and Haibo River and offshore waters of the north of the bay, leading to a mild contamination, while other waters in the bay were not polluted by the Cd content at all. In August, the variation of Cd content in the bay ranged from 0.11 to 1.11μg/L, more specifically, the Cd content hit the record high of 1.11μg/L in the offshore waters near the estuary of Dagu River and in the waters of the south of the bay mouth, making the waters polluted slightly, while other waters in the bay were not polluted by the Cd content at all. In October, the variation of the Cd content in the bay ranged from 0.12 to 1.11μg/L, more specifically, the Cd content reached a relatively high level of 1.04-1.11μg/L in the offshore waters near the estuary of Loushan River and Licun River, leading to mild contamination, while other waters in the bay were not polluted by the Cd content at all. There are three sources of the Cd content in the Jiaozhou Bay waters: rivers, main sea currents and surface runoff. In other words, these are three ways to transport the Cd content. In these ways, 0.96-1.53μg/L, 1.11μg/L and 1.10μg/L of Cd content are transported respectively. In this regard, the order from the largest to smallest of Cd content delivery is as follows: rivers, main sea currents and surface runoff. The Cd content transported by surface runoff is very close to that transported by main sea currents, indicating that the Cd content emitted by humans to land is consistent with that released to the oceans. Besides, the Cd content transported by the three sources is higher than or close to 1.00μg/L, suggesting that both lands and oceans are mildly polluted by the Cd content.

Spatiotemporal Variation of Pb Content Source Transportation in Jiaozhou Bay

Based on research data of the Jiaozhou Bay waters in May, August, and October 1992, the current transportation process and the various sources of Pb contents in the Jiaozhou Bay water body were studied. According to the Yang Dongfang migration law of the content, the results show that: after the ocean current with high levels of Pb content enters the Jiaozhou Bay, spatial change process of the sources carrying Pb content in May, August and October is shown with the transportation of the ocean current. Also, the model block diagram is used to reveal the change process of Pb content imported by ocean currents into the waters of Jiaozhou Bay. The location, magnitude, type, and time of the four sources of Pb content in the waters of Jiaozhou Bay were determined, which are the transportation of ships and terminals, surface runoffs, rivers, and offshore currents. Pb content of surface runoff transport is relatively low, and the transport time is short. Whereas Pb content of the ship terminal is increasing, and the time of transportation is also raising. And the content of Pb transported by rivers is the highest, and it has been transporting from land to sea nonstop throughout the year. Offshore currents carry a very high level of Pb content and constantly transporting it to the water body with low content of Pb. During the year, ships and terminals, land, and rivers were heavily polluted by Pb content, as well as the entire ocean. Among the rivers entering the sea around Jiaozhou Bay, there are four main ones: Haibo River, Licun River, Loushan River, and Dagu River. The sequence of Pb content transported by the rivers from high to low is listed as following: Licun River>Loushan River>Dagu River>Haibo River. The delivery time of Pb content in Licun River is the longer as delivery time in Haibo River, Loushan River and Dagu River is the same. Therefore, it is necessary to strictly control the Pb content from river transportation.

The Only Source of Cu Content from River Flow in Jiaozhou Bay

In August and October, 1991, the variation of Cu content in Jiaozhou Bay was 0.13-0.67μg/L, satisfying the Case I Sea Water Quality Standard. It showed that the water was not polluted by Cu content. Cu content was only transported by the river flow, specifically, 0.64μg/L from Haibo River, 0.59μg/L from Licun River and 0.67μg/L from Loushan River. The three rivers were not polluted by Cu content. The Cu content emitted by human was in the order of Loushan River, Haibo River and Licun River from high to low. However, the Cu contents in the three rivers were far less than 5.00μg/L, showing that the land was not polluted by Cu. Transported by different river flows, the Cu contents reaching the ocean were basically consistent, with a variation of 0.08μg/L. Further, the modelling diagram was established to display the transport path of Cu content to land, atmosphere and ocean in a quantitative way.

Biogeochemical characteristics and ecological risk assessment of pharmaceutically active compounds (PhACs) in the surface seawaters of Jiaozhou Bay, North China

The occurrence and distribution of 168 pharmaceutically active compounds (PhACs) in the surface seawater of Jiaozhou Bay (JZB) were investigated using ultra-high-performance liquid chromatography in tandem with a triple-quadrupole mass spectrometer equipped with an electrospray ionization source (UHPLC-ESI-MS-MS). Thirty-six compounds were detected, and 17 of these compounds were first detected in seawater, including sulfabenzamide, sulphacetamide, cephalonium, desacetyl-cefotaxime, cefminox, cefotaxime, cephradine, cefazolin, carprofen, nabumetone, glibenclamide, glimepiride, glipizide, prednisone, fluoromethalone, diazepam and amantadine. The total concentration of PhACs in the surface seawater ranged from 23.6 ng/L to 217 ng/L. The compounds found at the highest mean concentrations included amantadine (24.7 ng/L), lincomycin (8.55 ng/L), carprofen (8.30 ng/L), and tetracycline (7.48 ng/L). The PhAC concentration was higher in the inner bay than in the outside of the bay. In the inner bay, the eastern district showed higher concentrations of PhACs than the western district. Input from the Licun River may be the primary source of pollution. A statistically significant positive correlation was observed between nutrients and PhACs in seawater. Phosphate can be used to indicate the distribution of PhACs in JZB. Based on the individual risk quotient (RQ) values, lincomycin and ofloxacin posed high risks to the relevant aquatic organisms in JZB, especially in the eastern parts. Regular monitoring is required to evaluate the levels of PhACs as they are constantly released into JZB.

Gradually increasing Petroleum content in Jiaozhou Bay waters

Based on the survey data of Jiaozhou Bay in May, August and October 1992, this paper studied PHC content in Jiaozhou Bay and its horizontal distribution in the surface layer. The results showed that PHC content in the waterbodyof Jiaozhou Bay in May, August and October ranged from 0.006mg/L to 0.075mg/L, which met the first-class, secondand thirdseawater quality standard in China. This fact indicatedthat the waters of Jiaozhou Bay were slightly polluted by PHCduring this period. In May, PHC content in the waterbody of Jiaozhou Bay ranged from 0.006mg/L to 0.070mg/L, showingthat itwasslightly polluted by PHC.The PHC content in the coastalwater at the entrance of Haibo River was 0.070mg/L, beingslightly polluted; The PHCcontent in the other waters of Jiaozhou Bay ranged from 0.006mg/L to 0.042mg/L, not polluted. In August, PHC content in the waterbody of Jiaozhou Bay ranged from 0.019mg/L to 0.056mg/L, slightly polluted by PHC. The PHC content in the central water of theeastern bay was 0.056mg/L, slightly polluted; The PHC content in the other waters of Jiaozhou Bay ranged from 0.019mg/L to 0.048mg/L, not polluted. In October, PHC content in the waterbody of Jiaozhou Bay ranged from 0.028mg/L to 0.075mg/L, showing that it wasslightly polluted by PHC. The PHC content in the coastalwaters at the entrance of Loushan River and Licun River ranged from 0.055mg/L to 0.075mg/L,slightly polluted; The other waters inside Jiaozhou Bay were not polluted. The PHC content in the water at the bay mouthof Jiaozhou Bay was 0.054mg/L, slightly polluted. There were three main sources of PHC in the waters of Jiaozhou Bay, namely oil spill transportation at sea, open sea current transportation and river flow transportation. The PHC content transported through oil spill ranged from 0.042mg/L to 0.056mg/L, that transported through open sea current was 0.054 mg/L, and that transported through river flow ranged from 0.046mg/L to 0.075mg/L. Among them, the PHC content transported through river flow from Loushan River was 0.075mg/L, that from Haibo River was 0.070mg/L, andthat from Dagu River was 0.046mg/L. The PHC content transported through oil spills at sea, open sea currents and river flows caused slight pollution. Therefore, from May to August and then to October, the continuous transportation of much PHC content into the waters of Jiaozhou Bay kept elevating the low level of PHC contentin the waters of Jiaozhou Bay.