A comprehensive assessment of upgrading technologies of wastewater treatment plants in Taihu Lake Basin.

To meet the increasingly stringent discharge standards of wastewater treatment plants (WWTPs) in the Taihu Lake Basin, the Chinese government successively established the National Special Water Project Program to develop new technologies to retrofit and upgrade existing wastewater treatment processes during the 11th, 12th, and 13th Five-Year Plans. However, there is a lack of systematic sorting of the existing research outcomes, and thus hinders the application and promotion of the upgrade technologies. Based on the outcomes of the National Special Water Project and a field survey, this research analyzed the current status of wastewater treatment in the Taihu Lake Basin and systematically integrated the retrofitting measures of WWTPs in terms of achieving the Grade IA of the national standard and local stricter discharge standards (DB 32/1072-2018 and DB 33/2169-2018). In particular, the boundary conditions, design parameters, specific recommendations of the technologies, and some typical engineering cases were provided accordingly. Finally, this study discussed the future development directions of WWTPs during the upgrade process from the perspective of carbon neutrality and digitalization. The present work will hopefully assist in retrofitting and constructing WWTPs to achieve the stricter effluent discharge criteria and help optimize the design and construction of WWTPs in the best way.

Carrier effects of face mask-derived microplastics on metal ions: Enhanced adsorption by photoaging combined with biofilms, exemplified with Pb(â ¡).

Face masks have emerged as a significant source of microplastics (MPs) under the influence of biotic and abiotic interactions. However, the combined effects of abiotic photoaging and biofilm-loading on mask-derived MPs as carriers of metal ions are not clear. We investigated the Pb(Ⅱ) adsorption onto polypropylene (PP) and polyurethane (PU) mask-derived MPs treated by photoaging, biofilm-loading, and both combinations, evaluating the composite risks. PU mask-derived MPs (1.157.47 mg/g) exhibited greater Pb(Ⅱ) adsorption capacity than PP mask-derived MPs (0.842.08 mg/g) because of the presence of intrinsic carbonyl functional groups. Photoaging (30.5%, 88.4%), biofilm-loading (110.7%, 87.1%), and both combinations (146.7%, 547.0%) of PP and PU masks enhanced Pb(Ⅱ) adsorption compared to virgin mask-derived MPs due to the increase of oxygen-containing functional groups. High-throughput sequencing indicated that the structural morphology and chemical composition of masks significantly affected the microbial community. Adsorption mechanisms involved electrostatic force and surface complexation. A combination of photoaging and biofilms increased the ecological risk index of mask-derived MPs in freshwater, showing the risk level to be high (PP mask) and very high (PU mask). This research highlights the crucial role of photoaging combined with biofilms in controlling metal ion adsorption onto mask-derived MPs, thereby increasing the composite risks.

Photo-aged non-biodegradable and biodegradable mulching film microplastics alter the interfacial behaviors between agricultural soil and inorganic arsenic.

The impacts of microplastics (MPs) prevalent in soil on the transport of pollutants were urged to be addressed, which has important implications for ecological risk assessment. Therefore, we investigated the influence of virgin/photo-aged biodegradable polylactic acid (PLA) and non-biodegradable black polyethylene (BPE) mulching films MPs on arsenic (As) transport behaviors in agricultural soil. Results showed that both virgin PLA (VPLA) and aged PLA (APLA) enhanced the adsorption of As(Ⅲ) (9.5%, 13.3%) and As(Ⅴ) (22.0%, 6.8%) due to the formation of abundant H-bonds. Conversely, virgin BPE (VBPE) reduced the adsorption of As(Ⅲ) (11.0%) and As(Ⅴ) (7.4%) in soil owing to the "dilution effect", while aged BPE (ABPE) improved arsenic adsorption amount to the level of pure soil due to newly generated O-containing functional groups being feasible to form H-bonds with arsenic. Site energy distribution analysis indicated that the dominant adsorption mechanism of arsenic, chemisorption, was not impacted by MPs. The occurrence of biodegradable VPLA/APLA MPs rather than non-biodegradable VBPE/ABPE MPs resulted in an increased risk of soil accumulating As(Ⅲ) (moderate) and As(Ⅴ) (considerable). This work uncovers the role of biodegradable/non-biodegradable mulching film MPs in arsenic migration and potential risks in the soil ecosystem, depending on the types and aging of MPs.

Eutrophication and algal blooms in channel type reservoirs: a novel enclosure experiment by changing light intensity.

To explore eutrophication and algal bloom mechanisms in channel type reservoirs, a novel enclosure experiment was conducted by changing light intensity (LI) in the Daning River of the Three Gorges Reservoir (TGR). Square enclosures (side 5.0 m) were covered on the surface with shading materials of different thickness, and with their bases open to the river. Changes and characteristics of the main eutrophication factors under the same water quality and hydrodynamic conditions but different LI were evaluated. All experimental water samples were neutral and alkalescent, with high nitrogen and phosphate concentrations, low potassium permanganate index, stable water quality, and different LI. At the same water depth, LI decreased with increasing shade material, while dissolved oxygen and water temperature were both stable. The growth peak of phytoplankton was with light of 345-4390 lux underwater or 558-7450 lux above the water surface, and water temperature of 25.6-26.5 degrees C. Algae were observed in all water samples, accounting for 6 phylum and 57 species, with algal density changing frequently. The results showed that significantly strong or weak light was unfavorable for phytoplankton growth and the function together with suitable temperature and LI and ample sunshine encouraged algal blooms under the same water quality and hydrodynamic conditions. Correlation analysis indicated that algae reduced gradually lengthwise along water depth in the same enclosure while pH became high. The power exponent relationship between chlorophyll a (Chl-a) and LI was found by curve fitting, that is Chl-a = K(LI)(n).

Calcium nitrate as a bio-stimulant for anaerobic ammonium oxidation process.

This study explored the role of calcium nitrate as a bio-stimulant for anaerobic ammonium oxidation (anammox) process. The anaerobic sequencing batch reactor was firstly inoculated with malodorous river sediment and only fed with calcium nitrate until no marked endogenous release of ammonium in effluent (Phase 1). Subsequently, nitrite and ammonium were supplied to test the performance of anammox process (Phase 2). During the operation of Phase 1, the effluent ammonium increased firstly and then decreased. Additionally, continuous nitrite (about 1.54 mgN/L) was observed in the effluent. The microbial analysis showed the simultaneous increase of the relative abundance of heterotrophic denitrifier Denitratisoma and sulfur autotrophic denitrifier Thiobacillus from 0.15% to 5.37% and 0.21% to 4.19%, respectively. Besides, 15N isotopes trace and qPCR results showed that the contribution of anammox to total nitrogen (TN) removal increased from 3.07% to 27.6%, and that the anammox functional gene hzsB increased from 1.37 × 105 to 2.90 × 106 copies/g. These results indicated that calcium nitrate may induce partial mixotrophic denitrification (heterotrophic and sulfur autotrophic denitrification) to provide nitrite as electron acceptor for anammox, thus promoting the occurrence of anammox. In Phase 2, rapid ammonium and TN removal were accomplished in the initial operation with the reduction efficiency of 80.1% and 90.0%, respectively. The relative abundance of anammox bacteria Candidatus_Brocadia significantly increased from 0.01% to 7.15% during the operation of Phase 2. These findings further confirmed the above deduction. Taken together, calcium nitrate can be a promising bio-stimulant for anammox process by promoting the coupling of mixotrophic denitrification with anammox.

Sorption and leaching behaviors between aged MPs and BPA in water: The role of BPA binding modes within plastic matrix.

Due to the hydrophobicity and large specific surface area microplastics (MPs) have become the vector for the migration of environmental organic pollutants. Environmental aging process affects the physiochemical structure of MPs and their corresponding environmental behaviors, in which the effect of bisphenol A (BPA) binding mode within plastic matrix on aging behaviors of MPs is not reported. In this work, the structural properties and BPA sorption behaviors of low density polyethylene (LDPE) MPs with BPA additives and polycarbonate (PC) MPs with BPA monomers exposed to three types of artificial accelerated aging processes including UV/H2O, UV/H2O2, and UV/Cl2 systems were comparatively investigated. Virgin LDPE and PC exhibited obvious leakage of BPA additives or monomers. Aged LDPE had stronger sorption ability towards BPA in water environment with no observed leakage of BPA additives. While, aged PC had extremely high leakage of BPA monomers, which is similar to virgin PCs and was proved to be a persistent source of BPA release. The BPA sorption on aged LDPE or leaching from aged PC was influenced by aging processes, water pH, salinity, co-existing estradiol (E2), and water sources. This study reveals the potential ecological and environmental risks of MPs containing toxic additives/monomers during aging processes from a new perspective.

Highly efficient removal of bisphenol A by a novel Co-doped LaFeO3 perovskite/PMS system in salinity water.

Although it can effectively degrade refractory organic pollutants, advanced oxidation processes (AOPs) can be seriously interfered with the co-existing substance in salinity water. Herein, three-dimensional hierarchical cobalt-doped LaFeO3 perovskites (LaCo0.5Fe0.5O3) micron spheres composed of nano-rods were hydrothermally synthesized and applied to activate peroxymonosulfate (PMS) for degrading bisphenol A (BPA). Nearly 100% BPA was removed by LaCo0.5Fe0.5O3/PMS system in presence of more than 50 mM Cl- within only 2 min compared that of 30 min without Cl-, which was attributed to reactive chlorine species (RCS) including Cl• and HOCl with higher oxidation capacity. •OH and SO4•- produced by LaCo0.5Fe0.5O3 activating PMS played crucial roles as the source of RCS in LaCo0.5Fe0.5O3/Cl-/PMS system. The synergistic effect between ROS and RCS promoted by the enhanced oxygen vacancies and the efficient redox recycling of FeIII/FeII and CoIII/CoII. Other anions like SO42- and NO3- hardly affected the BPA degradation. BPA degradation efficiency was also improved either in a wide pH range or in the presence of natural organic matters in salty water. This work also demonstrated the potential application of FeCo bimetallic LaCo0.5Fe0.5O3 activating PMS system for degradation of BPA or other organic micropollutants in seawater system.

Size-dependent cellular internalization and effects of polystyrene microplastics in microalgae P. helgolandica var. tsingtaoensis and S. quadricauda.

Microplastics (MPs) are persistent contaminants in aquatic environments. Microalgae, as the main phytoplankton and primary producers, usually co-exist with MPs. Despite previous studies that have proved the interaction of MPs and microalgae, it is largely unknown whether MPs can be uptake into cells of microalgae. In this study, both marine P. helgolandica var. tsingtaoensis and freshwater microalgae S. quadricauda were respectively exposed to 10 mg/L polystyrene microbeads with five diameter sizes: 1.0, 2.0, 3.0, 4.0, and 5.0 µm. Confocal laser scanning and 3D image analysis showed that mean 24.0 % or 11.3 % cells of P. helgolandica var. tsingtaoensis contained 1.0 µm or 2.0 µm MPs after 72 h exposure. While mean 43.3 % or 15.3 % of S. quadricauda individuals engulfed 1.0 µm or 2.0 µm MPs within cells. But, none of 3.0-5.0 µm MPs were observed within algal cells. These results demonstrate the size-dependent cellular internalization of MPs in microalgae. Exposure to 1.0-2.0 µm PS MPs caused a significant reduction in the density of microalgae and influenced photosynthesis, which suggests cellular internalization of MPs can influence algal fertility and growth. This discovery first confirms cellular internalization of MPs in phytoplankton, of significance for the fate and eco-toxicity of MPs in the aquatic ecosystem.

Prevalence of microplastics in animal-based traditional medicinal materials: Widespread pollution in terrestrial environments.

Microplastics (MPs) pollution is an emerging environmental and health concern. MPs have been extensively observed in the aquatic environment, yet rarely investigated in the terrestrial ecosystem, especially in relation to health risks. To evaluate potential MPs pollution in land-dwelling animal medicine materials, we collected 20 types of small animal-based medicinal materials and 10 types of available fresh terrestrial animals from eight different regions in China. MPs were found in all medicinal materials with an average incidence rate of 94.67%. The abundance of MPs was in the range of 1.80 ± 0.38 to 7.80 ± 0.83 items/individual or 1.59 ± 0.33 to 43.56 ± 9.22 items/g (dry weight), with polymer distribution by polyethylene terephthalate (40.45%), rayon (30.64%), polyethylene (10.11%), nylon (7.35%), polypropylene (5.93%), and polyvinyl chloride (5.52%). The majority of MPs were microfibers (84.68%), with 15.32% of fragments. Moreover, MPs were directly observed in the intestine, detected in all ten types of fresh medicinal animals with the abundance of 0.83 ± 0.35 to 3.42 ± 0.46 items/individual. Furthermore, significant positive correlations (R: 0.32-0.99, p < 0.05) of MPs characteristics were found between medicinal materials and fresh animals, including shape, size, color, and polymer distribution of MPs. The results support that MPs in the medicinal materials were likely derived from living animals. This study demonstrates the prevalence of MPs in animal-based, traditional medicinal materials, and also suggests widespread MPs pollution in terrestrial environments and latent health risks.

Uptake and adverse effects of polyethylene terephthalate microplastics fibers on terrestrial snails (Achatina fulica) after soil exposure.

Recent studies have demonstrated the occurrence of microplastic fibers (MFs) in soil environments. To determine whether MFs are harmful for soil biota, we evaluated toxic effects on terrestrial snails (Achatina fulica) after 28 d exposure to polyethylene terephthalate MFs at concentrations of 0.01-0.71 g kg-1 (dry soil weight). Digestion kinetics experiments on 24 snails showed that MFs can be ingested and excreted within 48 h. We found the appearance of cracks and deterioration on the surface of MFs after depuration by the digestive system. Prolonged exposure to 40 snails showed that 0.14-0.71 g kg-1 MFs caused an average reduction of 24.7-34.9% food intake and 46.6-69.7% excretion. 0.71 g kg-1 MFs induced significant villi damage in the gastrointestinal walls of 40% snails, but did not influence the histology of the liver and kidney. Moreover, 0.71 g kg-1 MFs exposure reduced glutathione peroxidase (59.3 ±â€¯13.8%) and total antioxidant capacity (36.7 ±â€¯8.5%), but elevated malondialdehyde level (58.0 ±â€¯6.4%) in the liver, which indicates oxidative stress is involved in the toxic mechanism. Our results suggest that MFs have adverse impacts on the fitness of soil organisms, and highlight the ecological risks of microplastic pollution in terrestrial ecosystems.

Modulation of valence band maximum edge and photocatalytic activity of BiOX by incorporation of halides.

To better know the photocatalytic performance of bismuth oxyhalides (BiOX, X = Cl, Br, I) regulated by incorporation of halides within nanostructures, BiOX nanosheets were synthesized through morphology controllable solvothermal method and characterized systematically. The organic structural property greatly influences the photocatalytic activity of BiOX: 1) as for neutral molecular phenol, BiOX shows photocatalytic activity in the order of BiOCl > BiOBr > BiOI under simulated sun light irradiation, and the photo-oxidation kinetics follow Eley-Rideal mechanism; and 2) for adsorbed anionic orange II (OII) and cationic methylene blue (MB), BiOX shows photocatalytic activity in the order of BiOCl > BiOBr > BiOI, and the photo-oxidation kinetics follow Langmuir-Hinshelwood mechanism. The crystal structure of the catalyst also greatly influences the photocatalytic activity of BiOX: 1) The relative photo-oxidation power of O2•- radicals or HO radicals involved in this study were different which were quantitatively detected using typical radical trapping agent, separately; 2) The relative oxidation power of photogenerated holes (h+) in this study were in the order of BiOCl > BiOBr > BiOI, which may be ascribed to lowering the valence band maximum edge of BiOX through incorporation of halides as the atomic number of halides decreased. This study provides novel explanation for fabricating BiOX heterojunctions with tunable photocatalytic reactivity via regulating the halides ratio.

Microplastic and mesoplastic pollution in farmland soils in suburbs of Shanghai, China.

Microplastics are emerging pollutants which have been extensively detected in water environments. However, little is known about microplastic pollution in soil environments. In this study, we investigated microplastics and mesoplastics in farmland soils from twenty vegetable fields around the suburbs of Shanghai. In each site, three duplicate soil samples were collected from shallow (0-3 cm) and deep soils (3-6 cm), respectively. Microplastics (sizes of 20 µm - 5 mm) and mesoplastics (5 mm - 2 cm) were detected using methods of density extraction, 30% H2O2 digestion and micro-fourier transform infrared spectroscopy. The abundance of microplastics was 78.00 ±â€¯12.91 and 62.50 ±â€¯12.97 items kg-1 in shallow and deep soils, respectively. While, mesoplastics were found with abundance of 6.75 ±â€¯1.51 and 3.25 ±â€¯1.04 items kg-1 in shallow and deep soils. Among these micro(meso)plastics, 48.79% and 59.81% were in size of <1 mm in shallow and deep soils. The main morphotypes of microplastics included fiber, fragment and film, mostly in color of black or transparent. Moreover, we found that topsoil contained higher concentrations and larger sizes of micro(meso)plastics than deep soil. In addition, the vast majority of micro(meso)plastics were polypropylene (50.51%) and polyethylene (43.43%). This study reveals occurrence and characteristics of microplastic pollution in typical farmland soils. It provides important data for subsequent research on microplatics in the terrestrial ecosystem.

[Exploration of relationships between phytoplankton and related environmental factors in the Daning River during sensitive period of algal blooms].

To elucidate relationships between phytoplankton and related environmental factors, phytoplankton and environmental parameters of water quality in the Daning River were conducted using multivariate statistical analysis. Most of the investigated physico chemical parameters [water temperature, total nitrogen, nitrate-N (NO3(-) -N), pH and dissolved oxygen concentration (DO)] in Daning River are significantly different among those sampling sites (ANOVA, p < 0.05). The results indicate that the Daning River has a comparatively high spatial and temporal heterogeneity in the phytoplankton community composition (ANOVA, p < 0.05). The maximum cell density was recorded in Dachang and the minimum density was found at Wuxia-kou sites. Multi-algal species blooms were observed in the same time and place with the maximum density appeared. Correlation analysis was performed to illuminate the relationships between algae density and environmental variables, TN (r = - 0.789, p < 0.05), NO3(-) -N (r = - 0.825, p < 0.05) and NO2(-) -N (r = -0.803, p < 0.05) were negatively correlated with algae density. The results indicate that nitrogen soluble nutrients are key regulatory factors for phytoplankton abundance. The results of redundancy analysis (RDA) indicate that main soluble nutrients (TN, TP, NO3(-)-N and NO2(-)-N), suspended substance (SS) and transparency contributed significantly to phytoplankton community composition. Phytoplankton growth could enhance the pH value. The environmental characterizations and sample sites adjacency contributed significantly to phytoplankton community composition.

[Analysis of algal blooms in Da-Ning River of Three Gorges Reservoir].

According to the survey conducted from Apr. to Jun. 2007 and from Apr. to May. 2008, the changes of water quality, forms and distributions of nutrient salts and characters of algal blooms in Da-ning River of Three Gorges Reservoir (TGR) were studied. The results indicated that the concentrations of nitrogen and phosphorus nutrient were abundant during sensitive period of algal blooms in Da-ning River. Total nitrogen (TN) and total phosphorus (TP) values are 0.84-3.21 mg/L and 0.011-0.531 mg/L respectively, and the nutrients concentrations become high gradually from upstream to downstream. Total dissolved nitrogen (TDN) is the major form of TN accounting for 84%, and total dissolved phosphorus (TDP) is dominant (TDP/TP = 60%). Algal blooms bring phosphorus nutrient bio-concentration. The rates of TN and TP are all in excess of 16, which show eutrophication is limited by phosphorus. Potassium permanganate index and dissolved oxygen (DO) are at low levels and change stably. But chlorophyll a (Chl-a) becomes frequently, the value is 1.41-219.04 mg x m(-3). Significant positive correlations are all observed by correlation analysis between Chl-a and the main parameters (r(Chla-TP) = 0.453, r(Chla-potassium permanganate index) = 0.641, r(Chla-DO) = 0.584, r(Chla-pH) = 0.409, p < 0.01), but significant negative correlations are observed between Chl-a and Secchi depth (SD) (r(Chla-SD) = - 0.392, p < 0.01). The pH is fluctuated by multiparameter esp. in algal blooms. Widespread algae are observed by microscope during sensitive period of algal blooms in Da-ning River accounting for 8 phylum 82 genus 124 species, which Bacillariophyta and Chlorophyta are dominant, and then Cyanophyta and Pyrrophyta. Three whole watershed algal blooms break out in Da-ning River during the period, and the highest values of algal density are 14-1 427 times as many as the normal values. The dominant species of algal blooms are mostly involved with O. borgei, C. microporum, Chlorococcum humicola, P. morum and C. vulgaris of Chlorophyta; P. pleuronectes and T. oblonga of Euglenophyta; Cyclotella, Stephanodiscus astraea and Navicula of Bacillariophyta; P. elpatiewskyi of Pyrrophyta. Multi-algal species blooms are observed in the same time and place, and there are few algae in the estuary of Da-ning River to Changjiang River.

[Systematic investigation into winter and spring algal blooms in Daning River of Three Gorges Reservoir].

According to the survey conducted from winter and spring algal blooms, the changes of water quality and characteristics of Daning River of Three Gorges Reservoir (TGR) were studied. The results suggested that during the period of winter algal blooms centered on Tangjia bay in Daning river, chlorophyll a (Chl-a) had a wide range (the rates of (Chl-a)max and (Chl-a)min is 260). The contents of total nitrogen (TN), total phosphorus (TP) and potassium permanganate index were at very high levels because of bioaccumulation from algal blooms, but the values of dissolved oxygen (DO) and pH were very low. During winter algal blooms fastigium poor algae were observed accounting for 2 phylum 4 species, dominant species are Microcystis aeruginosa and Microcystis flos-aquae, the maximum value of algal density was 3.15 x 10(7) cells/L, and the correlation weighted nutrition state index was 80, which indicated water body was at high eutrophication level. However the spring algal blooms belonged to whole watershed outbreak, the values of Chl-a, TN, TP and potassium permanganate index became all markedly high with outbreak of algal blooms. There were 5 phylum 44 species algae being observed during spring algal blooms fastigium, different sections observed different dominant species and algal density values. The correlation weighted nutrition state index showed water of Dongping bar and Baishui River sections was at slight eutrophication level. During winter algal blooms there were significantly positive correlations between Chl-a and TN, TP, potassium permanganate index, water temperature, between pH and SD. Significantly negative correlations were observed between Chl-a and DO, SD, between pH and TN, TP, potassium permanganate index. In spring algal blooms significantly positive correlations were observed between Chi-a and TP, potassium permanganate index, DO, pH, between pH and Chla, TP, potassium permanganate index, DO, air temperature. Significantly negative correlations were observed between Chl-a and SD, between pH and SD.

[Analysis of nitrogen distribution characters and their sources of the major input rivers of Three Gorges Reservoir].

According to the survey conducted from Jan. 2004 to Dec. 2005, the seasonal characters of nitrogen in the water of input rivers of Three Gorges Reservoir (TGR) were discussed, and the forms and distributions of nitrogen among three major input rivers (Changjiang river, Jialingjiang river and Wujiang river) were studied. The results indicate that some primary hydrologic values of input rivers have seasonal characters, and they are in the danger range, which might bring algal bloom. The average contents per year of total nitrogen are 1.55-2.15 mg/L in the three monitor sections of input rivers of TGR, and Wulong monitor section is more severe than the others. The contents of total nitrogen in abundant water period are much higher than them in low water period, which displays the nonpoint source pollution has far-reaching influence upon total nitrogen. The total dissolved inorganic nitrogen (DIN) is the major form of total nitrogen and further nitrate nitrogen (NO3(-)-N) is dominant accounting for 70% or more of DIN. Ammoniacal nitrogen is the uppermost input form of nitrogen pollution of input rivers of TGR. Ammoniacal nitrogen was oxidated to nitroso-nitrogen, and then it was oxidated to nitrate nitrogen using up a lot of dissolved oxygen of water. Nitrate nitrogen sources include agricultural runoff, city pollution water, city runoff and slow-releasing from submersed soil, whenas nitrogen-ammonia (NH4(+)-N) origins are city pollution water, industrial pollution water, and a little source of living garbage and bilgewater.

[Analysis of phosphorus distribution characters and their sources of the major input rivers of Three Gorges Reservoir].

The seasonal characters of the water flux and suspended substance, phosphorus in the water of input rivers of Three Gorges Reservoir (TGR) were discussed, and the their distributions among three major input rivers (Changjiang river, Jialingjiang river and Wujiang river) were studied, according to the survey conducted from Jan. 2004 to Dec. 2005. The results indicate that those parameters' seasonal changes are obvious. The flux and suspended substance in abundant water period are more higher than them in low water period, which displays suspended substance origins from bedload and that the water and soil severely lose in drainage areas of three input rivers. In the three monitor sections of input rivers of TGR, the average contents per year of total phosphorus are about 0.12-0.29 mg/L, which exceeds the 1970s level of the three input rivers. Most of total phosphate is total solid phosphate (TPP) exceeding 75% of them. TP and TPP have both distinct positive correlation with the flux and suspended substance in water of input rivers of TGR, and TPP and TP have also the same correlation, which means that phosphate pollution in the input rivers of TGR comes from bedload. The nonpoint source pollution has had far-reaching influence upon phosphate pollution. Nitrogen and phosphate are not the major limiting factor of the nutritious salts in the input rivers of TGR. The rate of between nitrogen and phosphate (N/P) is in higher level (above 30), that is phosphate first will reach lower level and maybe become the limiting factor of the nutritious salts in the input rivers of TGR.