Establishment of a diatom-total phosphorus transfer function for lakes on the Songnen Plain in northeast China

To understand the relationship between planktonic diatoms and environmental variables in the lakes on the Songnen Plain,northeast(NE)China,we investigated water quality and planktonic diatoms from 71 sampling points in 27 lakes,based on which Canonical Correspondence Analysis(CCA)was conducted.The result show that planktonic diatoms displayed certain responses to environment gradients,and the total phosphorus(TP)explained the maximum variation of planktonic diatom species among the 15 environmental variables,suggesting that TP was the most important and significant environmental parameter affecting the distribution of diatom species.In addition,we established a diatom-total phosphorus transfer(DTPT)function,of which component 5 of the weighted averaging partial least squares regression(WAPLS)was chosen to and compared with a series of weighted average regression(WA)models and WA-PLS models.According to the jackknifing statistical test,the component 5 of WA-PLS models provided a lower root-mean-square error prediction(RMSEP=0.202)and a higher correlation coefficient between observation and prediction(R^2_Jack=0.759).After deletion of three outliers,the root-mean-square error prediction of the DTPT function was reduced(RMSEP=0.169)while the correlation coefficient between observation and prediction was increased(R^2_Jack=0.823).Therefore,this DTPT function performed better than other regional TP models in the world.However,it remains demanding for expanding the background dataset to improve the prediction ability of the model.

DISTRIBUTIONS OF TOTAL, INORGANIC AND ORGANIC PHOSPHORUS IN THE SEDIMENTS NEAR THE HUANGHE RIVER ESTUARY

For some hundred surface sediment samples from five cores taken in two cruises near the Huanghe River Estuary, total phosphorus (TP (.inorganic phosphorus (IP (and organic phosphorus (OP)were determined.On the average, 527×10-6, 455×10~6 and 72×10-6 were found for TP,IP and OP for the surface sediments taken in the two cruises. The distribution of OP and IP was controlled by the sample particle size: OP content increased with the decreasing of the sample particle size, while the maximal value of IP was found in the silt fraction due to the existence of apatite in our samples. Vertical distributions reflected well the channel change of the Huanghe River. Results from the multiple regressions between the three forms of phosphorus and the percentages of different particle size agreed well with the analytical data.

Continuous flow analysis of dissolved total phosphorus in seawater by UVK_(2)S_(2)O_(8) online digestion method

Several methods for analysis of dissolved total phosphorus in seawater were reviewed. Discussions were focused on UVirradiation and persulphate oxidation methods which are the most popular dissolved organic phosphorus determinationmethods presently. The compounds used for the phosphorus recovery test were categorized into three groups accordingto their chemical structure. It was found that low power UV irradiation can decompose POC or PC bonds efficientlybut may be inefficient for POP bonds. Heating-bath in acid condition is useful for decomposing POP bonds. Usingthe continuous flow analysis system (Auto-analyzer II), UV digestion and heating-bath, series experiments were carriedout based on the above analysis. Eleven model compounds were employed for the phosphorus recovery test and thefactors influencing the decomposition efficiency of dissolved compounds containing phosphorus were clarified. Finally,the optimal design for determination of dissolved total phosphorus in seawater based on the routine continuous flowanalysis system was presented. For the organic mono-phosphate, the recovery is more than 90% and a recovery of33%~51% was obtained for inorganic or organic polyphosphates. Up to now, this is the highest decompositionefficiency for dissolved phosphorus based on the continuous flow analysis system.

Optical anisotropy of black phosphorus by total internal reflection

Although abundant research on the anisotropy of van der Waals(vd W)materials has been published,we undertake an in-depth study of their optical properties as they have an important guiding role for light control in two-dimensional(2D)nanospace.As an example,we study the reflectance of few-layered black phosphorus(BP)in the total internal reflection(TIR)mode in detail.We demonstrate that its optical anisotropy can be changed on a large scale by varying the incident angles,polarization states,and the in-plane rotation angles of the BP samples.Theoretical analysis indicates that the phenomena observed are common to all the atom-thick biaxial crystals,so these conclusions can be widely applied to other anisotropic 2D materials.This research furthers the current understanding of the properties of BP more comprehensively,and provides guidance for developing new optoelectronic applications,especially when BP and other atom-thick biaxial crystals are integrated with TIR devices.

A data-derived soft-sensor method for monitoring effluent total phosphorus

The effluent total phosphorus(ETP) is an important parameter to evaluate the performance of wastewater treatment process(WWTP). In this study, a novel method, using a data-derived soft-sensor method, is proposed to obtain the reliable values of ETP online. First, a partial least square(PLS) method is introduced to select the related secondary variables of ETP based on the experimental data. Second, a radial basis function neural network(RBFNN) is developed to identify the relationship between the related secondary variables and ETP. This RBFNN easily optimizes the model parameters to improve the generalization ability of the soft-sensor. Finally, a monitoring system, based on the above PLS and RBFNN, named PLS-RBFNN-based soft-sensor system, is developed and tested in a real WWTP. Experimental results show that the proposed monitoring system can obtain the values of ETP online and own better predicting performance than some existing methods.

Advances in Detection of Total Phosphorus and Application of Titanium Dioxide Photocatalytic Technology

Total phosphorus is an important index in the monitoring of water quality, but the existing detection methods waste time and energy during the process of di- gestion. In this paper, the existing detection technology of total phosphorus and the digestion technology of organic phosphorus in the determination of total phosphorus were summarized firstly, of which photocatalytic degradation technology, as one of new technologies of organic phosphorus digestion, was introduced. Afterwards, tita- nium dioxide photocatalytic technology and its application were summarized, and its application prospects were expected.

Effects of Conservation Methods of Water Samples on Determination of Total Phosphorus

Effects of conservation methods of water samples on determination of total phosphorus were analyzed from aspects of methods of adding conserving agent, SS concentration, natural sedimentation time, conservation temperature and time. The results showed that SS concentration in water and natural sedimentation time had the greatest impact on the determination of total phosphorus, while the influence of methods of adding conserving agent, conservation temperature and time was relatively smaller. TP concentration in water samples conserved irregularly was higher than the standard value due to the existence of SS and microorganisms in water, and the deviation became larger with the increase of SS concentration in water. In addition, quality control measures and matters needing attention during the conservation process of water samples were put forward to improve the accuracy of TP concentration.

Effects of Sediment on the Test of Total Phosphorus in Water

Based on previous studies,the effects of the type,content,particle size and state of sediment on the determination of total phosphorus in water are analyzed.The results show that the type of sediment has a certain influence on the determination result of total phosphorus,and the influence cannot be ignored.The degree of influence depends on the specific type.Sediment content is negatively correlated with the determination result of total phosphorus in water.That is,the higher the sediment content is,the lower the determination result is.The particle size of sediment is positively correlated with the determination result of total phosphorus in water.That is,the larger the particle size of sediment is,the higher the determination result is.Among the static,semi-suspended and completely suspended states,the sediment in the static state has the least impact on the determination of total phosphorus,and it has the greatest impact on the determination of total phosphorus when it is fully suspended.Therefore,in the analysis and testing process of total phosphorus,attention should be paid to the impact of sediment to improve the authenticity of the test results.

基于香溪河中游水体总磷总氮高光谱估算模型比较

研究通过地面高光谱遥感技术,针对香溪河中游的水质参数——总氮(TN)和总磷(TP)进行反演分析。研究选取160个数据样本,采用了单波段分析、一阶微分波段分析、波段比值分析、双波长差异指数、归一化差异指数以及偏最小二乘回归(PLS)分析6种方法建立反演模型。结果显示,单波段分析和一阶微分波段分析对于TP和TN的反演效果不佳。而波段比值分析在一定程度上提高了TN的反演准确性,其二次幂回归分析的R^(2)可达0.3674。在双波长差异指数的3次幂分析中,TP的预测模型达到最高R^(2)值,为0.4014。PLS回归分析在TN反演模型中表现突出,波段差值混合模型的R^(2)达到0.39,RMSEP为0.501,ARE为40.278%,展现一定的预测准确性。研究结果有助于利用高光谱遥感预测香溪河中游TN、TP长时间变化趋势,但模型预测精度仍受限于数据集和水体类型,未来研究需进一步探索和优化模型算法。

柴达木盆地干柴沟地区勘探突破及启示

柴达木盆地西部干柴沟地区历经60余年勘探未获重大油气发现。2019年以来,通过强化山地三维地震勘探技术攻关和深化高原咸化湖相混积型碳酸盐岩成储、成藏研究,油气勘探终获突破,发现了古近系下干柴沟组构造油气藏,同时英雄岭页岩油和湖相碳酸盐岩岩性油气藏勘探也展现出良好前景。研究成果主要得益于以下几点:①高品质三维地震资料揭示干柴沟地下构造形态,发现东翼发育断背斜,为油气聚集提供了有利圈闭条件;②大面积咸化湖相混积碳酸盐岩具备储集能力,碎屑岩、湖相碳酸盐岩和膏盐岩层在纵、横向上均呈有序分布,构成了良好的生-储-盖组合;③基于全油气系统理论,认为研究区常规油气(源外)和非常规油气(源内)立体成藏。剖析干柴沟地区油气勘探历程发现:①地震勘探技术进步是干柴沟复杂构造区地下构造圈闭得以落实和油气地质特征得以揭示的基础;②干旱咸化湖盆发育的大面积混积碳酸盐岩不仅是烃源岩而且具备储集能力,这一认识拓展了勘探领域,是勘探取得突破的关键;③全油气系统理论的引入,推动油气勘探向源内拓展,揭示了英雄岭页岩油的良好勘探前景。

浅水湖泊TP分布的迎风有限元数值模型研究

从控制方程出发，以Ｇａｌｅｒｋｉｎ有限元法为基础，结合有限元法的较新改进，推导、建立了一个适合于浅水湖泊ＴＰ浓度分布计算的二维迎风有限元的数值模型，并将其应用于太湖。

2013-2022年洞庭湖水质变化及污染成因分析

以2013-2022年洞庭湖及入湖河流、洞庭湖出口20个水质断面连续10年监测数据为基础,研究洞庭湖水质时空变化特征与污染成因.研究结果表明:洞庭湖水质总氮质量浓度ρ(TN)年平均值在1.21~2.60 mg/L之间;入湖河流ρ(TN)年平均值在1.28~2.88 mg/L之间,洞庭湖出口ρ(TN)年平均值在1.47~2.17 mg/L之间;洞庭湖水质总磷质量浓度ρ(TP)年平均值在0.036~0.128 mg/L之间,入湖河流ρ(TP)年平均值在0.035~0.167 mg/L之间,洞庭湖出口ρ(TP)年平均值在0.048~0.132 mg/L之间.洞庭湖水质时空分布差异明显,空间分布上,TN、TP呈现出入湖河流、洞庭湖出口、湖体依次降低趋势;时间分布上,TN、TP在2013-2020年呈下降趋势,2020-2022年下降趋势明显放缓甚至有所上升.RDA分析结果进一步表明:入湖河流ρ(TN)和ρ(TP)及湖体水位变化对洞庭湖ρ(TN)和ρ(TP)影响较大,洞庭湖水质还受其他污染因素影响.建议加强入湖污染物管控措施,在不同水文阶段积极开展水文调控,改善洞庭湖水质.

LAS对人工快滤系统去除TP的影响

文章运用人工土柱模拟的方法来研究LAS对人工快滤系统去除TP的影响。研究结果表明,随着污水中LAS浓度(≤100mg/L)的增加,人工快滤系统对TP的去除率表现为逐渐下降。TP的去除率大小为处理Ⅰ>处理Ⅱ>处理Ⅲ>处理Ⅳ。在延长干化时间条件下,TP的去除率增大,并且LAS浓度越大效果越明显。LAS对人工快滤系统中TP的去除有着显著的影响;但合理地控制工艺参数能够实现LAS和TP的有效去除。

TPS based on trilateration for the feed measurement of FAST

Five-hundred-meter Aperture Spherical radio Telescope( FAST) is the largest sensitive single dish radio telescope in the world,in which the control and measurement of the feed is one crucial section of the FAST control system. Trilateration is presented to obtain three-dimensional coordinate for tracking feed focus cabin. Every three total stations chase prism movement to be attached on feed focus cabin and the prism position is determined from the measured distances based on the principle of trilateration. Therefore,feed position is determined from three prisms on the focus cabin. This study is to assess the accuracy and reliability of trilateration calculation on tracking focus cabin of FAST. Different arrangement of total stations on trilateration is theoretically studied. Through experiment,the proposed method shows that the accuracy is better than that of the polar coordinate measurement. The average root mean square error is lower than 0. 6 mm,which is found to have high accuracy and reliability.

Identifying Nonpoint Sources of Phosphorus and Nitrogen: A Case Study of Pollution That Enters a Freshwater Wetland (Laguna Cartagena, Puerto Rico)

Point and nonpoint sources of phosphorus (P) and nitrogen (N) can cause reductions in water quality, including eutrophication. Nonpoint pollution represents a special challenge because of dispersed not easily identifiable sources such as the runoff from soil, nutrients, and other chemicals from agricultural fields and residential areas. Laguna Cartagena is a tropical freshwater wetland, situated in southwestern Puerto Rico. It is a eutrophic ecosystem, and its eutrophication is caused by both external nutrient loading and internal, mainly by phosphorus. This wetland has been affected by phosphorus loading from inorganic agricultural fertilizer in this historically oligotrophic wetland system until the end of subsidized fertilizer use and sugar cane cultivation in the late 1990s. This study identifies: 1) nonpoint sources of phosphorus (SRP, Soluble Reactive Phosphorus and TP, Total Phosphorus) and nitrogen (nitrate, nitrite, and ammonia) that enter Laguna Cartagena;and 2) the role of precipitation events on the contributions of phosphorus and nitrogen loading to ecosystems. Herein we assess water samples from five channelized external sources of P and N that enter Laguna Cartagena at two-week intervals from October 2013 through November 2014. Rainfall data were obtained weekly from a rain gauge. Standard methods were used for all chemical analyses. Results showed that the channelized waterways that carry water to the lagoon can be classified as hypereutrophic (>100 μg/L) for TP concentrations and oligotrophic (<200 μg/L) for nitrogen concentrations. Currently agriculture (rice and cattle) is the predominant land use at the nearby University of Puerto Rico (UPR) Lajas Agricultural Experiment Substation, the predominant nonpoint source of nutrient pollution (SRP, TP and ammonia) in the principal channelized water sources to the lagoon. Current nutrient loads are likely derived from fertilizers applied to the Substation’s rice fields, and a high density livestock. The second important cause of external surface water degradation (SRP, TP and ammonia) is the discharge from rural households in the drainage basin that discharge greywater directly to the environment, as indicated by the results from Cerro Alto hills immediately to the north of the lagoon. Precipitation also was associated with SRP, TP and ammonia loads.

Effects of Long-term Located Fertilization on Evolution of Available Phosphorus and Phosphorus Pool in Shandong Fluvo-aquic Soil

This study was conducted to investigate the effects of long-term located fertilization on soil phosphorus,the changes of soil available phosphorus(OlsenP),the evolution of soil total phosphorus(TP)and the ratio change of Olsen-P to TP(PAC)by 33-year fertilization experiments in winter wheat-summer maize rotation system in Shandong fluvo-aquic soil.Eight treatments were designed as no fertilization(CK),nitrogen fertilizer(N),nitrogen and phosphate fertilizer(NP),nitrogen and potassium fertilizer(NK),phosphate and potassium fertilizer(PK),nitrogen-phosphate-potassium fertilizer(NPK),reduced NPK fertilizer(N(15)PK),and increased NPK fertilizer(N_(25)PK).Meanwhile,eight organic fertilizer-added treatments were designed based on the application of inorganic fertilizer the same as the above ones.The results showed that TP,Olsen-P and PAC of treatments added with organic fertilizer were higher than those without organic fertilizer,and those of the treatments applied with phosphate fertilizer were higher than those of no phosphate fertilizer.With the increase of years,soil P pool decreased due to crop absorption,nutrient loss and morphological transformation and other causes under the treatments of without and only phosphate fertilizer,while remained stable under the treatments added with organic fertilizer.The PAC values were generally lower in fluvo-aquic soil,and it could be improved by the application of organic fertilizer.On the whole,the application of chemical phosphate fertilizer combined with organic fertilizer could improve the phosphorus content in soil and ensure the supply of phosphorus nutrition.This study would provide scientific basis for fertilization management and soil fertility in fluvo-aquic soil.

Effects of Phosphorus Concentration on the Treatment of Domestic Wastewater by a Combination of Hydrolytic Acidification and Biological Aerated Filter Filled with Mussel Shells

The combination of hydrolytic acidification and biological aerated filter （BAF） filled with mussel shells was used to treat domestic wastewater, and the removal rates of chemical oxygen demand （COD）, ammonia nitrogen （NH3-N） and total phosphorus （TP） by the system were analyzed under different TP concentrations. When TP concentration ranged from 12.39 to 14.69 mg/L, the removal rate of COD was the best, over 90.92% ; as TP concentration varied from 2.26 to 2.61 mg/L, the removal rates of NH3-N and TP were the best, up to 100.00% and 76.38% respectively. The results show that it is feasible to use mussel shells as the media of BAF, and TP concentration has certain influence on the performance of the system dealing with domestic wastewater.

冠状动脉侧支循环及PCI治疗对CTO患者Tp-e间期、Tp-e/QT比值的影响

目的探讨冠状动脉侧支循环(coronary collateral circulation,CCC)对冠状动脉慢性完全闭塞病变(chronic total coronary occlusion,CTO)患者Tp-e间期、Tp-e/QT比值的影响,以及经皮冠状动脉介入(percutane⁃ous coronary intervention,PCI)治疗对CTO患者Tp-e间期、Tp-e/QT比值的影响及临床意义。方法本研究选取邵阳市中心医院心内科2018年7月至2020年12月期间CTO患者共150例。CCC采用Rentrop评分进行分级,将入选患者分为CCC不良组(Rentrop 0级、1级组),CCC良好组(Rentrop 2级、3级组)。测量各组患者心电图中Tp-e间期、Tp-e/QT比值。另从以上研究对象中按是否成功行PCI治疗分为PCI治疗成功组及PCI治疗失败组。观察两组患者PCI治疗前及治疗后心电图中Tp-e间期、Tp-e/QT比值的情况。结果CCC良好组患者Tp-e间期、Tp-e/QT比值低于CCC不良组,差异有统计学意义(P<0.05)。PCI治疗成功组与PCI治疗失败组患者术前临床资料及Tp-e间期、Tp-e/QT比值比较,差异有统计学意义(P<0.05)。PCI治疗成功组患者术后Tp-e间期、Tp-e/QT比值较术前下降,差异有统计学意义(P<0.05)。PCI治疗成功组患者术后Tp-e间期、Tp-e/QT比值低于PCI治疗失败组,差异有统计学意义(P<0.05)。结论CTO患者中,良好的侧支循环形成有利于降低心室跨壁复极离散度指标Tp-e间期、Tp-e/QT比值,更好地恢复CTO患者心肌细胞电生理稳定性;成功的PCI治疗可以减少CTO患者心室复极离散度指标Tp-e间期、Tp-e/QT比值,从而降低室性心律失常发生的风险。

Measuring Quality of Economic Growth Incorporating Environment and Social Welfare:a Total Productivity Approach with an Application on China

By extending the traditional productivity theory,a new concept total productivity( TP) is introduced. Using a directional distance function approach,the concept is applied to measuring economic growth of 8 economic regions of China covering an 18 years period( 1997—2014) and test its convergence. Results showed that TP grew at an average rate of 6. 6% per year led mainly by technical change( 6. 5%). When environmental undesirable outputs are included,the Middle Yellow River,Northwest and Southwest regions of China witnessed higher productivity changes. Results of the convergence analysis revealed that China had made progress in reducing regional imbalance in growth. Inclusion of undesirable output showed that the energy-saving emission reduction policies had speed up the convergence rate of TP and environment oriented productivity. However,China's welfare oriented productivity is still very low.

Salt effect on MUCT system performance of nitrogen and phosphorus removal

The effect of salinity on biological nitrogen and denitrifying phosphorus removal was investigated in a Modified University of Cape Town(MUCT)system.Removal rates of COD,NH_(4)^(+)-N,NO_(3)^(-)-N,NO_(2)^(-)-N,phosphorus and the sludge characteristics at salt concentrations(0.0,3.2,6.4,11.2 and 16.0 g L^(-1))were analyzed.With the salt concentration increasing,all the COD,NH_(4)^(+)-N,TN and TP removal rates exhibited a trend of decline,and exhibited an initial reduction and subsequent increase at every stage of salt concentration.NH_(4)^(+)-N,TN and TP removal rates were 92.7%,51.5%and 67.2%in 16 g L^(-1) salt concentration,respectively.And they were outperformed the literature reported and acceptable in practical applications.When the salinity of wastewater changed from 0.0 to 16.0 g L^(-1),the biomass yield coefficients increased from 0.0794 to 0.126 g VSS/g COD.Increased salinity had a detrimental effect on phosphorus-accumulating organisms(PAOs)and denitrifying PAOs(DPAOs)(especially DPAOs).Therefore,phosphorus removal gradually depended on PAO.The simultaneous nitrification and denitrification(SND)rate and nitrogen removal rate(including nitrification rate,denitrification rate,and total nitrogen removal rate)gradually decreased with the increased salinity.