Assessment of the Comparative Toxicity of Sewage Effluent from 10 Sewage Treatment Plants in the Area of Sydney, Australia using an Amphipod and Two Sea Urchin Bioassays

In 1995, Sydney Water Corporation undertook an ecological and human health risk assessment for 10 sewage treatment plants (STPs) that discharge primary (6 STPs) and secondary (4 STPs) treated effluents into coastal waters in the Sydney and Illawarra regions, NSW, Australia. A program of toxicity testing of effluent from the 10 STPs was undertaken to determine the toxic effects of the effluents and as a weight-of-evidence study for the risk assessment.

Three types of bioassays were used to test multiple samples of effluent from each STP. Tests used were the sea urchin (Heliocidaris tuberculata) fertilization and larval development bioassays and the amphipod (Allorchestes compressa) survival bioassay.

Comparing between STPs, primary treated effluent was slightly more toxic than secondary treated effluent for all three tests. The highest toxicity was recorded for those STPs that use primary treatment and discharge to the shoreline. Comparing between tests, the sea urchin fertilization bioassay was slightly more sensitive than the sea urchin larval development bioassay, with the amphipod survival bioassay being the least sensitive.

This paper will describe the results of this toxicity testing program and discuss the application of the study results as weight-of-evidence for the risk assessment study.     

The occurrence and distribution of pharmaceutical compounds in the effluents of a major sewage treatment plant in Northern Taiwan and the receiving coastal waters

The pharmaceutical residues in waste water from the largest sewage treatment plant (STP) in Northern Taiwan and in seawater around the effluent discharged area were determined. An environmental risk assessment for the marine environment was conducted based on the environment risk quotient (ERQ). The concentrations of the analyzed compounds in STP influent and effluent were generally higher than those found in coastal seawater. Relatively higher values were found at the estuarine mouth and the discharged area, suggesting that the STP effluent is a point source. The removal efficiency and half life of the analyzed compounds were 6.3-46.8% and 3-18 days, respectively. The ERQ value theoretical calculation was generally greater than 1. However, when the measured concentrations replaced the predicated concentrations, the ERQ values were considerably lower than 1. Therefore, our results call for a re-evaluation of the risks posed by pharmaceuticals to coastal marine ecosystems in Northern Taiwan.     

Occurrence of endocrine-disrupting chemicals in riverine sediments from the Pearl River Delta, China

The endocrine-disrupting chemicals (EDCs) was investigated in 28 riverine sediments from the Pearl River system, China and analyzed by an ultrasonication extraction and GC-MS method. The concentrations of 4-tert-octylphenol (OP), 4-nonylphenol (NP), and bisphenol A (BPA) in the sediments were in the ranges of <2.0-210, 107-16198 and <1.7-430 ng/g dw, respectively. The steroid estrogens estrone (E1) and 17β-estradiol (E2) in the sediments ranged from <1.3 to 10.9 ng/gdw and from <0.9 to 2.6 ng/gdw, respectively. The spatial distribution of these chemicals was related to the discharge of domestic and industrial wastewater along the rivers. The positive correlation between EDCs and total organic carbon indicates that sedimentary organic carbon is an important factor in controlling the distributions of EDCs. Compared with other previous studies, the ZR and DR rivers from the PRD were heavily contaminated by APs and BPA.     

Alkylbenzenes in mussels from South and South East Asian coasts as a molecular tool to assess sewage impact

Alkylbenzenes, molecular markers of sewage, were measured in 34 green mussels collected from India, Indonesia, Malaysia, Thailand, Cambodia, Vietnam, and the Philippines together with blue mussels collected from Tokyo Bay, Japan. Linear alkylbenzene (LAB) concentrations in South and South East Asian countries ranged from 10 to 1640 ng-∑LAB/g-dry tissue. In some populous cities, LAB concentrations were similar or higher than those found in northern Tokyo Bay which is heavily impacted by sewage effluents. I/E ratios (a ratio of internal to external isomers of LABs) in the South and South East Asian countries (1–3) were much lower than those in Tokyo Bay (3–8), indicating sewage discharged in the coastal zone is poorly treated (e.g., raw sewage and/or primary effluents). Alkylbenzenes with branched alkyl chains, tetrapropylene-based alkylbenzenes, were also detected in mussels from Indonesia and Philippines. This “tell-tale” sign indicates that poorly degradable detergents are still in use in this area, although they have long been phased-out in many industrialized countries.     

Occurrence of endocrine-disrupting chemicals in riverine sediments from the Pearl River Delta,China

The endocrine-disrupting chemicals (EDCs) was investigated in 28 riverine sediments from the Pearl River system, China and analyzed by an ultrasonication extraction and GC–MS method. The concentrations of 4-tert-octylphenol (OP), 4-nonylphenol (NP), and bisphenol A (BPA) in the sediments were in the ranges of <2.0–210, 107–16198 and <1.7–430 ng/g dw, respectively. The steroid estrogens estrone (E1) and 17β-estradiol (E2) in the sediments ranged from <1.3 to 10.9 ng/g dw and from <0.9 to 2.6 ng/g dw, respectively. The spatial distribution of these chemicals was related to the discharge of domestic and industrial wastewater along the rivers. The positive correlation between EDCs and total organic carbon indicates that sedimentary organic carbon is an important factor in controlling the distributions of EDCs. Compared with other previous studies, the ZR and DR rivers from the PRD were heavily contaminated by APs and BPA.     

Phenolic endocrine disrupting chemicals (EDCs) in Anzali Wetland, Iran: elevated concentrations of 4-nonylphenol, octhylphenol and bisphenol A

We have studied the distribution and value of phenolic endocrine disrupting chemicals (EDCs) in surface sediment samples taken from Anzali Wetland, Iran. These samples were collected from 22 stations during the time span of June-May 2010. In each of the sampling stations, we detected 4-nonylphenol (4-NP), octylphenol (OP), and bisphenol A (BPA) with maximal concentrations of 29, 4.3, and 7 μg g(-1) dry weight (dw), respectively. High levels of alkylphenols (APs) and BPA were also found near urban areas. Furthermore there were no significant differences between those stations in terms of the detected levels. One of the important factors in controlling the fate of these compounds in the aquatic environment appeared to be Total Organic Carbon (TOC). Hierarchical cluster analysis showed differences in the biomarker characteristics of EDCs and TOC between the stations. Our findings indicate that EDCs are ubiquitous in sediments from northeast Wetlands of Iran, contaminating the aquatic habitats in this area.     

Steroid markers to assess sewage and other sources of organic contaminants in surface sediments of Cienfuegos Bay,Cuba

Analyses of faecal steroids in coastal sediments from Cienfuegos Bay Cuba indicate chronic sewage contamination at the main outfalls from the city, where concentrations of coprostanol up to 5400 ng g⁻¹ (dry wt) were measured. In contrast, steroid concentrations and compositions from sites from the south part of the Bay are characteristic of uncontaminated sewage environments. The levels of coprostanol in the Cienfuegos sediments compares to the lower to mid-range of concentrations reported for coastal sediments on a world-wide basis, with sedimentary levels markedly below those previously reported for heavily impacted sites. This study delivers baseline data for further investigation of the effectiveness of the proposed sewerage plan promoted by the GEF project in Cienfuegos. Investigations on the correlations between faecal steroids and other organic contaminants confirmed that the major source of petroleum hydrocarbons within the bay was associated with the sewage effluents from the Cienfuegos city.     

Water Quality Management Based on Division of Dry and Wet Seasons in Pearl River Delta,China

In the Pearl River Delta (PRD), river water quality deteriorates continually due to the population increase and ongoing industrialization and urbanization. In this study, a water quality management paradigm based on the seasonal variation is proposed. For better exploring the seasonal change of water quality, wavelet analysis was used to analyze the division of dry and wet seasons in the PRD during 1952–2009. Then water quality seasonal variation in 2008 and relevant impact factors were analyzed by multivariate statistic methods as a case to make some management measures. The results show that there are some differences of dry and wet seasons division among different years. Wet season mainly appear from April to September, which occupy the largest proportion among the 58 years (about 70%) and then followed by the wet season from May to October (about 13.8% of the total years). As to the water quality of 2008, significant differences exist between dry and wet seasons for 17 water quality parameters except TP, , Fe²⁺, and Zn²⁺. Levels of parameters pH, EC, COD_Mn, BOD₅, , , and Cl^? in dry season are much higher than those in wet season. In dry season the variations of river water quality are mainly influenced by domestic sewage, industrial effluents, and salt water intrusion. While in wet season, except the aforementioned pollution sources, drainages from cultivated land and livestock farm are also the main factors influencing water pollution. Thus, water quality management measures are proposed in dry and wet seasons, respectively. The results obtained from this study would further facilitate water quality protection and water resources management in the PRD.     

Spatiotemporal variability of hypoxia and eutrophication in Manila Bay,Philippines during the northeast and southwest monsoons

Hypoxia in Manila Bay, Philippines was previously reported during the northeast monsoon (dry season) in February 2010. In this study, four more field surveys of the same 31 stations were conducted in July 2010, August 2011 and 2012 (wet season, southwest monsoon), and February 2011 (dry season, northeast monsoon). During the wet season, bottom hypoxia spread northward towards the coast with dissolved oxygen (DO) ranging from 0.12 to 9.22 mg/L and the bay-wide average reaching 2.10 mg/L. Nutrient levels were elevated, especially near the bottom where dissolved inorganic nitrogen reached 22.3 μM (July 2010) and phosphorus reached 5.61 μM (August 2011). High nutrient concentrations often coincided with low near-bottom DO content. Our work builds on the preliminary assessment of hypoxia in Manila Bay, the importance of repeated temporal studies, and shows hypoxia to prevail significantly during the southwest monsoon (wet season) when increased freshwater discharge caused strong water column stratification.     

Environmental response to sewage treatment strategies: Hong Kong's experience in long term water quality monitoring

In many coastal cities around the world, marine outfalls are used for disposal of partially treated wastewater effluent. The combined use of land-based treatment and marine discharge can be a cost-effective and environmentally acceptable sewage strategy. Before 2001, screened sewage was discharged into Victoria Harbour through many small outfalls. After 2001, the Hong Kong Harbour Area Treatment Scheme (HATS) was implemented to improve the water quality in Victoria Harbour and surrounding waters. Stage I of HATS involved the construction of a 24 km long deep tunnel sewerage system to collect sewage from the densely populated urban areas of Hong Kong to a centralized sewage treatment plant at Stonecutters Island. A sewage flow of 1.4 million m³ d⁻¹ receives Chemically Enhanced Primary Treatment (CEPT) followed by discharge via a 1.2 km long outfall 2 km west of the harbor. The ecosystem recovery in Victoria Harbour and the environmental response to sewage abatement after the implementation of HATS was studied using a 21-year data set from long term monthly water quality monitoring. Overall, the pollution control scheme has achieved the intended objectives. The sewage abatement has resulted in improved water quality in terms of a significant reduction in nutrients and an increase in bottom DO levels. Furthermore, due to the efficient tidal mixing and flushing, the impact of the HATS discharge on water quality in the vicinity of the outfall location is relatively limited. However, Chl a concentrations have not been reduced in Victoria Harbour where algal growth is limited by hydrodynamic mixing and water clarity rather than nutrient concentrations. Phosphorus removal in the summer is suggested to reduce the risk of algal blooms in the more weakly-flushed and stratified southern waters, while nutrient removal is less important in other seasons due to the pronounced role played by hydrodynamic mixing. The need for disinfection of the effluent to reduce bacterial (E. coli) concentrations to acceptable levels is also confirmed and has recently been implemented.     

Adsorption and desorption behaviors of selected endocrine disrupting chemicals in simulated gastrointestinal fluids

An in vitro technique using simulated gastrointestinal (GI) fluids was applied to investigate the desorption of selected endocrine disrupting chemicals (EDCs), i.e. bisphenol A (BPA) and 17 α-ethinylestradiol (EE2), from the marine sediment in the digestive environment. The results show that the GI fluids suppressed chemical adsorption and greatly increased the desorption of BPA and EE2 from the sediment. Pepsin in the gastric fluid would compete for the adsorption sites with the adsorbates, and bile salts in the intestinal fluid had a solubilization effect on the chemicals. The amount of chemical release from the sediment in different fluids followed intestinal (fed) > intestinal (fasted) > gastric > saline water. During the dynamic desorption tests, 62% and 21% of sediment-bound BPA and EE2, respectively, could be released into the simulated GI fluids. The enhanced desorption of EDCs from sediment in the digestive system would make the pollutants more bioavailable in the ecosystem.     

Chlorohydrocarbon pesticides in the Australian marine environment after banning in the period from the 1970s to 1980s

The chlorohydrocarbon pesticides (CHPs) (principally DDT, dieldrin, hexachlorocyclohexane (HCH) including lindane, chlordane, heptachlor and heptachlorepoxide, aldrin and hexachlorobenzene (HCB)) were used extensively in Australia during the 1960s and 1970s. These were progressively banned from the 1970s with DDT being totally banned in 1987. The levels in marine waters are believed to have progressively declined as indicated by water in the Brisbane River, which consistently fell from maximum concentrations of about 1.7 μg/l in 1972–1973 to not detectable in 1986–1987. In some urban areas sediment concentrations, up to 1700 μg/kg dry weight, were recorded in the early 1990s which may reflect the reworking and exposure of older more contaminated material. Fish exhibited consistent occurrence of DDT, HCH, dieldrin and HCB through the 1970s to the 1990s. Maximum concentrations of DDT and dieldrin occurred generally in the 1970s at 40.3 and 8.8 μg/g wet weight, and minimums in the 1990s at 2.4 and 0.041 μg/g wet weight respectively. Inputs of dialdrin from sewage and DDT from the broad environment, reflected by the calculated daily human uptake in the diet, were shown to decline with half-lives of 1.1–1.5 and about 3 years respectively. This evidence suggests that banning of the CHPs has greatly reduced the inputs into the marine environment with consequent reductions in concentrations in biota but there is the occasional occurrence of relatively high concentrations.     

Ground and surface water quality along a dambo transect in Chihota smallholder farming area,Marondera district,Zimbabwe

In many smallholder farms in sub-Saharan Africa dambos are used for grazing and crop production especially horticultural crops. Increased use of dambos especially for crop production can result in ground and surface water pollution. Ground and surface water quality along a dambo transect in Chihota, Zimbabwe, was investigated between October 2013 and February 2014. The transect was divided into; upland (control), dambo gardens (mid-slope) and the river (valley bottom). Water samples for quality assessment were collected in October 2013 (peak of dry season) and February 2014 (peak of rainy season). The collected water samples were analysed for pH, faecal coliforms, total nitrogen, electrical conductivity, total dissolved solids (TDS), and some selected nutrients (P, K, Ca, Mg, Na, Zn, and Cu). Water pH was 7.0, 6.4 and 6.1 for river water, garden and upland wells respectively. During the wet season total nitrogen (TN) concentrations were 233 mg/L for uplands, 242 mg/L for gardens and 141 mg/L for the river. During the dry season, TN concentrations were all below 20 mg/L, and were not significantly different among sampling stations along the dambo transect. Dry season faecal coliform units (fcu) were significantly different and were 37.2, 30.0 and 5.0 for upland wells, garden wells and river respectively. Wet season faecal coliforms were also significantly different and were 428.5, 258.0 and 479.4 fcu for upland wells, garden wells and river respectively. The other measured physico-chemical parameters also varied with sampling position along the transect. It was concluded that TN and fcu in sampled water varied with season and that wet season concentrations were significantly higher than dry season concentrations. High concentrations of faecal coliforms and total N during the wet season was attributed to increased water movement. Water from upland wells, garden wells and river was not suitable for human consumption according to WHO standards during both the dry and wet seasons.     

Isotopic and microbial indicators of sewage pollution from Stone Town, Zanzibar, Tanzania

In Stone Town, Zanzibar, sewage treatment is minimal, with a biological oxygen demand reduction to 60% and no removal of bacteria or nutrients. Here, Stone Town's sewage pollution was studied by measuring Enterococci and NH(4)(+) concentrations in seawater and δ(15)N of benthic organisms; samples were collected along the Stone Town shoreline and from offshore coral reefs. Public perceptions of sewage pollution were investigated via interviews. Enterococci from the Stone Town shoreline exceeded USEPA guidelines for recreational use. Benthic organisms from two of the four reefs were relatively enriched (δ(15)N>10 ‰), indicative of sewage derived N. δ(15)N values of organisms from Stone Town exceeded 16 ‰. A strong correlation was found between Enterococci and δ(15)N across sites, while step-wise regression indicated rainfall and tidal stage as important predictors for bacterial concentrations. These data provide an important impact assessment from which the efficacy of future policy and management change can be assessed.     

Influence of the Pearl River estuary and vertical mixing in Victoria Harbor on water quality in relation to eutrophication impacts in Hong Kong waters

This study presents water quality parameters such as nutrients, phytoplankton biomass and dissolved oxygen based on 11 years of water quality data in Victoria Harbor and examined how the Pearl River estuary discharge in summer and year round sewage discharge influenced these parameters. Nutrients in Victoria Harbor were strongly influenced by both the Pearl River and sewage effluent, as indicated by the high NO(3) inputs from the Pearl River in summer and higher NH(4) and PO(4) in Victoria Harbor than both its sides. N:P ratios were low in the dry season, but increased to >16:1 in the wet season, suggesting that P is potentially the most limiting nutrient in this area during the critical period in the summer. Although there were generally high nutrients, the phytoplankton biomass was not as high as one would expect in Victoria Harbor. In fact, there were high concentrations of chl near the bottom well below the photic zone. Salinity near the bottom was lower in Victoria Harbor than at the two entrances to Victoria Harbor, suggesting strong vertical mixing within Victoria Harbor. Therefore, strong vertical mixing and horizontal advection appear to play an important role in significantly reducing eutrophication impacts in Victoria Harbor. Consequently, dissolved oxygen near the bottom was low in summer, but only occasionally dipped to 2 mgL(-1) despite the high organic loading from sewage effluent.     

Spatiotemporal variations of dissolved inorganic carbon and controlling factors in a small karstic catchment,Southwestern China

Dissolved inorganic carbon (DIC) is the most important carbon component in karst aquatic system where fluid is highly transmissive, but has rarely been examined in the subtropical karst critical zone (K-CZ). In this study, concentrations of dissolved solutes and isotopic compositions of DIC (δ¹³C_DIC) at 11 sites of a 73.4 km² karstic catchment in Southwestern China were analysed monthly in order to uncover the spatiotemporal variations of both DIC and its dominant sources, and to identify relevant controlling factors. Both DIC concentrations and δ¹³C_DIC were highly variable, ranging from 2.52 to 5.85 mmol l⁻¹ and from −15.7 to −4.5‰, respectively. DIC in underground water (UGW) was higher in concentration and more depleted in ¹³C compared to surface water (SFS). DIC concentrations showed an inconsistent seasonal trend with other solutes, with higher values in the wet season at some sites. δ¹³C_DIC values were lower in the wet season than in the dry season. The results of mixing model IsoSource revealed spatiotemporal patterns of DIC sources. During the dry season, carbonate weathering was the primary contributor to DIC in UGW (excluding in the middle reaches). However, during the wet season, soil CO₂ was the dominant source of DIC in both UGW and SFS, and it was higher than in the dry season. Overall, there are significant spatiotemporal disparities and highly transmissive characteristics of both DIC and its sources in the K-CZ, which are controlled by multiple factors. This study also highlights that rainfall may play a crucial role in accelerating carbon dynamics in the K-CZ. High-frequency sampling campaigns in high-flow periods and deep analyses are needed in future work to elucidate the related processes and mechanisms. © 2019 John Wiley & Sons, Ltd.     

Schoenoplectus californicus as Potential Remover of Metal Elements from Mine Effluents: A Laboratory Assessment

Acid mine drainage (AMD) is one of the most significant environmental challenges facing the mining industry worldwide. For this reason, many methods for AMD treatment are developed, being wetlands a good option for metal elements removal from these mining effluents. The efficiency of Peruvian native plants such as Schoenoplectus californicus (S. californicus) to remove metal elements in effluents through artificial wetlands is studied. Batch removal tests are carried out with different effluents containing copper, zinc, lead, and iron. For iron-metal binary effluents, copper, zinc, and lead are removed by 82%, 75%, and 88%; while in the effluent containing all metals, the removal rate is 90% and 92% for copper and lead, respectively. According to the preliminary results, it is concluded that iron interferes more in the removal of zinc and lead than in copper from binary effluents. The use of S. californicus turns out to be an efficient, attractive, and economical alternative for the treatment of effluents contaminated with copper, zinc, lead, and iron.     

Sources and transport of nitrate constrained by the isotopic technique in a karst catchment: an example from Southwest China

The concentration and isotopic composition of nitrate were analyzed to improve an understanding of nitrate sources and transformation processes in a typical karstic agricultural field in the Houzhai catchment, Guizhou Province, Southwest China. The results revealed that no distinct spatial pattern of content and isotopic composition of nitrate exists in this karst catchment. Nitrate in surface stream (SFS) had slightly lighter isotopic composition and lower concentration compared with nitrate in subterranean stream (STS) during the dry season. Concentrations of SFS nitrate increased to concentrations similar to those of STS during the wet season. The isotopic values indicated that nitrate were mainly impacted by manure sources during the dry season and influenced by a mix of chemical fertilizer and manure during the wet season. The denitrification rates were roughly estimated based on the isotopic compositions of nitrate after considering volatilization and ignoring assimilation. The calculated result showed that approximately one fifth of nitrate load was removed by denitrification in the catchment. Annual nitrate flux from the outlets accounted for 14.2% of applied total fertilizers used in the catchment, approximately 85% of total transported flux from the catchment in the wet season. Furthermore, chemical weathering processes were enhanced by using nitrogen fertilizer because liberated protons and enhanced HCO₃^? flux were produced through by nitrification. Copyright © 2014 John Wiley & Sons, Ltd.     

Laboratory simulation of the salt weathering of schist: 1. Weathering of schist blocks in a seasonally wet tropical environment

Data describing sediment generation focusing on the temporal evolution of size gradation are required for the prediction of long‐term landform evolution. This paper presents such data for the salt weathering of a quartz‐chlorite schist obtained from the Ranger Uranium Mine in northern Australia. Rock fragment samples are subjected to three different climate regimes: (1) a dry season climate; (2) a wet season climate (both based on observations at the Ranger site); and (3) an oven‐drying sequence designed to test the sensitivity of the weathering process by exposing the rocks to more extreme temperatures. Two MgSO₄ salt solutions are applied, one being typical of wet season runoff and the other a more concentrated solution. Salt solution is applied daily in the wet season experiments and once only at the beginning of the dry season experiments. Results of the experiments reveal four stages of weathering. The kinetics of each stage are described and related to the formation of sediment of different sizes. Wet season climate conditions are shown to produce greater moisture variability and lead to faster weathering rates. However, salt concentrations in the wet season are typically lower and so when climate is combined with observed salt concentrations, the dry and wet season experiments weather at approximately equal rates. Finally, small variations in rock properties were shown to have a large impact on weathering rates, leading to the conclusion that rock weathering experiments need to be carefully designed if results are to be used to help predict weathering behaviour at the landscape scale. Copyright © 2006 John Wiley & Sons, Ltd.     

新疆艾比湖流域枯、丰水期三维荧光光谱特性及其与水质的关系

以艾比湖流域主要入湖河流为研究对象,在5月（丰水期）和8月（枯水期）分别沿博尔塔拉河（博河）和精河进行采样,采用平行因子模型（PARAFAC）和三维荧光区域积分法对水体三维荧光特性进行研究并对其与水质的关系在枯、丰水期下的变化进行探讨.结果表明①河流DOM在枯水期与丰水期都含有C1（240、425 nm） UVC类腐殖质,C2（225、290 nm）紫外区内络氨酸类有机物,C3（230/280、330 nm）蛋白类有机物,C4（265、260 nm）腐殖质类共4种组分.通过对水体三维荧光进行区域积分可以看出DOM荧光成分的占比在不同时期的变化.博河在枯水期时EEM光谱中的区域Ⅲ富里酸含量低于丰水期,枯水期时区域Ⅱ芳香类蛋白质、区域Ⅳ可溶性微生物代谢物以及区域Ⅴ类腐殖质酸高于丰水期;对于精河来说,区域Ⅱ芳香类蛋白质和区域Ⅳ可溶性微生物代谢物在枯水期的含量高于丰水期,区域Ⅲ富里酸和区域Ⅴ类腐殖质酸的含量枯水期低于丰水期,这表明水体腐质化程度较高.②本研究选取了一些常规的荧光指数来描述枯、丰水期水体的荧光指数特性.经研究发现,精河的荧光指数、自生源指数和腐殖化指数在不同时期的变化幅度较小,而博河的变化幅度较大.③将荧光指数与水质参数进行相关性分析并建模,结果表明枯水期自生源指数（BIX）与化学需氧量呈显著正相关,相关系数R=0.688;丰水期时BIX与铵态氮浓度呈显著负相关,相关系数R=-0.493.通过对比分析艾比湖主要入湖河流的三维荧光光谱特性与水质在枯、丰水期时的关系进一步表明水体中DOM的特性以及在枯、丰水期下的差异,为艾比湖流域的治理改善提供一定的理论支持和参考依据.