Trends in Iron and Phosphorus Loading to Lake Ontario from Waste Water Treatment Plants in Hamilton and Toronto

Resurgences in toxic cyanobacterial blooms, especially Microcystis, have been observed in the lower Great Lakes over the last decade in areas where total phosphorus (TP) levels are below historically high levels. Compliance with regulatory standards for TP in municipal wastewater effluent has likely depended on increased use of iron chloride as a flocculating agent for phosphorus removal in some wastewater treatment plants (WWTP). Since some ecological research suggests that increased supply of biologically available forms of iron may stimulate cyanobacterial growth, TP and iron loadings from WWTPs in the Hamilton Harbour and Toronto areas were examined. TP loadings from the Hamilton and Toronto WWTPs over the last 10–15 years have, in general, not increased. Effluent sampling frequency for iron is much lower than for a regulated parameter such as TP, consequently there is greater uncertainty in loading estimates. Moreover, iron loading estimates are available for only one plant from 1996 and three plants from 1999 so long-term loading trends cannot be established. Iron loading from the Humber WWTP in Toronto increased 5-fold between 2001–2004 while iron loading from the Woodward WWTP in Hamilton is quite high for its size. Iron consumption (i.e., dosing) data are available for three plants from the early 1990s. There was a clear increase in iron consumption by the Burlington-Skyway WWTP beginning in 1997 which was accompanied by a clear decrease in TP loading. However, there were no clear long-term trends in iron consumption in the Toronto plants even when normalized for flow. Increased monitoring and reporting of iron in WWTP effluent by all WWTP operators is recommended along with a review of methods for iron retention.     

Assessments of Composite and Discrete Sampling Approaches for Water Quality Monitoring

Achieving an operational compromise between spatial coverage and temporal resolution in national scale river water quality monitoring is a major challenge for regulatory authorities, particularly where chemical concentrations are hydrologically dependent. The efficacy of flow-weighted composite sampling (FWCS) approaches for total phosphorus (TP) sampling (n?=?26–52 analysed samples per year), previously applied in monitoring programmes in Norway, Sweden and Denmark, and which account for low to high flow discharges, was assessed by repeated simulated sampling on high resolution TP data. These data were collected in three research catchments in Ireland over the period 2010–13 covering a base-flow index range of 0.38 to 0.69. Comparisons of load estimates were also made with discrete (set time interval) daily and sub-daily sampling approaches (n?=?365 to >1200 analysed samples per year). For all years and all sites a proxy of the Norwegian sampling approach, which is based on re-forecasting discharge for each 2-week deployment, proved most stable (median TP load estimates of 87–98%). Danish and Swedish approaches, using long-term flow records to set a flow constant, were only slightly less effective (median load estimates of 64–102% and 80–96%, respectively). Though TP load estimates over repeated iterations were more accurate using the discrete approaches, particularly the 24/7 approach (one sample every 7 h in a 24 bottle sampler - median % load estimates of 93–100%), composite load estimates were more stable, due to the integration of multiple small samples (n?=?100–588) over a deployment.     

Determination of first flush criteria using dynamic EMCs (event mean concentrations) on highway stormwater runoff.

Recently the Ministry of Environment in Korea has developed the total maximum daily load program in accordance with the target pollutant and its concentration goal on four major large rivers. Since the program is largely related to regional development, nonpoint source control is both important and topical. Of the various nonpoint sources, highways are stormwater intensive land uses since they are impervious and have high pollutant mass emissions from vehicular activity. The event mean concentration (EMC) is useful in estimating the loadings to receiving water bodies. However, the EMC does not provide information on the time varying changes in pollutant concentration or mass emissions, which are often important for best management practice development, or understanding shock loads. Therefore, in this study a new concept, the dynamic EMC determination method, will be introduced to clearly verify the relationship between EMC and the first flush effect. Three monitoring sites in Daejeon metropolitan city areas were equipped with an automatic rainfall gauge and a flow meter for accumulating the data such as rainfall and runoff flow. The dynamic EMC method was applied to more than 17 events, and the improved first flush criteria were determined on the ranges of storm duration and accumulated rainfall.     

中小河流非点源污染治理负荷估算及分区分类研究

针对中小河流非点源污染治理过程中存在的河流数量众多、基础资料缺乏、重点难以把握等状况,提出一套基于遥感（RS）和地理信息系统（GIS）技术的污染负荷估算方法,识别主要污染物和污染源,确定重点防治地区和流域。以哈尔滨地区为例,在分析非点源污染来源基础上,使用输出系数模型（ECM）估算2010年非点源TN、TP污染负荷及空间分布特征,计算TN、TP等标负荷,确定主要污染物。根据等标污染负荷空间分布差异,将哈尔滨地区划分为5个污染负荷区,以流域为单元用聚类分析法将中小河流归为5类,确定了区域中小河流非点源污染防治重点。     

苏南运河对太湖主要入湖河流污染物通量的贡献率

为了解苏南运河对太湖主要入湖河流污染物通量的贡献,基于一维平原河网水量、水质数学模型,模拟计算了2011年受苏南运河影响的主要入湖河流的入湖污染物通量(COD、氨氮、TN、TP),量化分析了苏南运河对主要入湖河流入湖污染物通量的贡献率。研究结果表明:苏南运河主要影响湖西区的太湖主要入湖河流,对湖西区主要入湖河流入湖通量的总体贡献率约为23%,其中对太滆运河的贡献率最大,约42%,漕桥河次之,约23%,对太滆南运河、社渎港、陈东港污染物通量的贡献率由北向南依次减小。     

丹江口水库入库非点源污染负荷的计算与讨论

正确估算丹江口水库入库非点源污染负荷对于水源区水环境保护具有重要意义。根据丹江口库区6条主要入库河流汉江、天河、堵河、丹江、老灌河、淇河控制水文站2013年逐日流量数据,采用数字滤波法对基流进行了分割。以逐日流量、河川基流量和代表污染物（CODMn和TP）2013年逐月浓度监测值为基础,采用通量法计算了背景污染负荷和点源污染负荷、非点源污染负荷。结果表明：（1） 6条河流入库流量占总入库流量的95.9%,非点源污染已成为丹江口水库水质变化的主导因素。（2） 汉江是入库污染负荷的最大来源,其次是堵河。（3） 由于非点源污染伴随降雨汇入河道,水库污染负荷主要集中于丰水期,2013年度丰水期CODMn和TP的比例分别达到了80.8%和90.9%。      

Cumulative metal leaching from utilisation of secondary building materials in river engineering.

The present paper estimates the utilisation of bulky wastes (minestone, steel slag, phosphorus slag and demolition waste) in hydraulic engineering structures in Dutch parts of the rivers Rhine, Meuse and Scheldt over the period 1980-2025. Although they offer several economic, technical and environmental benefits, these secondary building materials contain various metals that may leach into river water. A leaching model was used to predict annual emissions of arsenic, cadmium, copper, chromium, lead, mercury, nickel and zinc. Under the current utilisation and model assumptions, the contribution of secondary building materials to metal pollution in Dutch surface waters is expected to be relatively low compared to other sources (less than 0.1% and 0.2% in the years 2000 and 2025, respectively). However, continued and widespread large-scale applications of secondary building materials will increase pollutant leaching and may require further cuts to be made in emissions from other sources to meet emission reduction targets and water quality standards. It is recommended to validate available leaching models under various field conditions. Complete registration of secondary building materials will be required to improve input data for leaching models.     

River flow indexing using British benthic macroinvertebrates: a framework for setting hydroecological objectives

A method linking qualitative and semi‐quantitative change in riverine benthic macroinvertebrate communities to prevailing flow regimes is proposed. The Lotic‐invertebrate Index for Flow Evaluation (LIFE) technique is based on data derived from established survey methods, that incorporate sampling strategies considered highly appropriate for assessing the impact of variable flows on benthic populations. Hydroecological links have been investigated in a number of English rivers, after correlating LIFE scores obtained over a number of years with several hundred different flow variables. This process identifies the most significant relationships between flow and LIFE which, in turn, enables those features of flow that are of critical importance in influencing community structure in different rivers to be defined. Summer flow variables are thus highlighted as being most influential in predicting community structure in most chalk and limestone streams, whereas invertebrate communities colonizing rivers draining impermeable catchments are much more influenced by short‐term hydrological events. Biota present in rivers with regulated or augmented flows tend to be most strongly affected by non‐seasonal, interannual flow variation. These responses provide opportunities for analysing and elucidating hydroecological relationships in some detail, and it should ultimately be possible to use these data to set highly relevant, cost‐effective hydroecological objectives. An example is presented to show how this might be accomplished. Key areas of further work include the need to provide robust procedures for setting hydroecological objectives, investigation of habitat quality and LIFE score relationships in natural and degraded river reaches and evaluation of potential links with other biological modelling methods such as RIVPACS. Copyright © 1999 John Wiley & Sons, Ltd.     

Site length for biological assessment of boatable rivers

There is increasing international interest by water resource management agencies worldwide in developing the capacity for quantitative bioassessments of boatable rivers. This interest stems from legal mandates requiring assessments, plus growing recognition of the threats to such systems from multiple and co‐varying stressors (e.g. chemical pollutants, physical habitat alterations, altered flow regimes, channel modifications and alien species). The elevated cost and inefficiencies of jurisdictionally‐ and taxonomically‐segregated assessments is widely recognized, as is the desire to obtain comparable data that can be easily shared among political jurisdictions and ecological regions. The objectives, sampling methods, indicators, site‐scale sampling designs and geographic extent of the resources being sampled differ among programmes, thereby limiting such data exchanges. Our objective in this paper is to review major biological assessment design alternatives for boatable rivers, with special attention given to the sample site length from which data are collected. We suggest that sufficient site length determinations should be based on the survey objectives, the relative heterogeneity of the habitat template, and the quality of data necessary for meeting programmatic data quality objectives. Future sampling effort studies should be designed to allow separate samples of several short sub‐sites at many diverse sites to generate multiple data points for each site. Data from those multiple sub‐sites should be analysed using randomization‐based data evaluation methods. We hope that our recommendations will be useful to the maximum number of institutions, including those with limited funds and a purely local focus, as well as those responsible for sampling at continental geographic extents. Copyright © 2010 John Wiley & Sons, Ltd.     

Application of continuous turbidity sensors to supplement estimates of total phosphorus concentrations in the Grand River,Ontario, Canada

Accurate estimates of total phosphorus (TP) loadings to eastern Lake Erie are critical for developing load reduction targets and for determining if commitments are being met under the Great Lakes Water Quality Agreement, 2012 (GLWQA). Currently, loading calculations from Canadian priority tributaries are supported by year-round event-focused water quality sampling using automated samplers and laboratory water quality measurements. Here we evaluate the suitability of continuously-measured parameters, namely turbidity and flow, to supplement or enhance knowledge about TP concentrations in the Grand River, ON, by providing continuous data alongside event-focused sample measurements. A series of simple and multiple linear regression models were evaluated and compared with respect to their ability to predict TP water concentrations as a function of different combinations of explanatory variables. Explanatory variables included turbidity, flow, season and flow condition (i.e. hysteresis). The models that performed best explained 63–65% of the variation of TP which is comparable to surrogate model applications in the U. S and elsewhere. Additional model calibration work is needed due to gaps in turbidity data particularly during high flow events. We emphasize the need for continued automated, event-focused water quality sampling. However, provided that operational challenges are overcome, our results indicate that sensor-derived water quality parameters to predict TP concentrations is a promising technique that may supplement and improve nutrient loading estimates in the Grand River into the future and provides guidance for the utilization of this method in other tributaries.     

Utilizing RBF-NN and ANFIS Methods for Multi-Lead ahead Prediction Model of Evaporation from Reservoir

Evaporation as a major meteorological component of the hydrologic cycle plays a key role in water resources studies and climate change. The estimation of evaporation is a complex and unsteady process, so it is difficult to derive an accurate physical-based formula to represent all parameters that effect on estimate evaporation. Artificial intelligence-based methods may provide reliable prediction models for several applications in engineering. In this research have been introduced twelve networks with the RBF-NN and ANFIS methods. These models have applied to prediction daily evaporation at Layang reservoir, located in the southeast part of Malaysia. The used meteorological data set to develop the models for prediction daily evaporation rate from water surface for Layang reservoir includes daily air temperature, solar radiation, pan evaporation, and relative humidity that measured at a case study for fourteen years. The obtained result denote to the superiority of the RBF-NN models on the ANFIS models. A comparison of the model performance between RBF-NN and ANFIS models indicated that RBF-NN method presents the best estimates of daily evaporation rate with the minimum MSE 0.0471 , MAE 0.0032, RE and maximum R² 0.963.     

Intrinsic and extrinsic sources of phosphorus loading into the Nyando River,Kenya

The Nyando River supports a large human population and an enriched biodiversity. The basin has undergone extreme modification over the last century through changes in hydrological changes and land‐use activities. The impacts of the changes have severely shifted the ecology of the river from desirable to less desirable. Of all the major rivers draining into Lake Victoria‐Kenya, the Nyando River is consistently the most turbid and exhibits the greatest phosphorus load. The present study investigated the present limnological status and sources of phosphorus loads between 2015 and 2016 through water and sediment sampling during high and low flow regimes. The samples were analysed for various phosphorus fractions, including soluble reactive phosphorus (SRP), total phosphorus in water (TP_w), non‐apatite inorganic phosphorus (NAIP), apatite phosphorus (AP), inorganic phosphorus (IP), organic phosphorus (OP), total phosphorus in sediments (TP_s) and elemental compositions. The measured SRP and TP_w concentrations indicated hypertrophic conditions, with means for both high and low flows ranging from 79.3 to 165.7 μg P/L, and 200.0 to 243.9 μg P/L, respectively. The AP concentrations were high, with mean measurements for high and low flows being 766.9 and 790.5 mg/kg, respectively. The sources of high phosphorus loads were established to be both natural and anthropogenic, with major drivers being the industrial establishments along the river basin. Erosion of the catchment phosphorus‐enriched carbonatite rocks and river banks also contributed significant phosphorus loads. Enhanced effluent treatment, quarry dust containment, improved forest cover and regeneration of riverine buffer strips are recommended to restore the river's ecosystems.     

河流控制断面污染负荷计算方法比较

为了选择适合我国资料条件的河流控制断面污染物负荷估算方法,采用渭河下游潼关吊桥断面长期周水质监测数据和渭河华县断面逐日流量资料,选择了8种方法分别计算出潼关吊桥断面年污染负荷,并将各种方法的计算结果与实际负荷对比。结果表明:方法 7,即用流量加权浓度乘以年流量,分别计算丰、平、枯各季负荷,然后相加求和来计算年污染负荷的方法精度较高。最后对部分方法提出了改进措施。     

Nutrient concentrations and loadings in the St. Clair River–Detroit River Great Lakes Interconnecting Channel

Long-term (2001–2015) water quality monitoring data for the St. Clair River are presented with data from studies in the Detroit River in 2014 and 2015 to provide the most complete information available about nutrient concentrations and loadings in the Lake Huron–Lake Erie interconnecting corridor. Concentrations of total phosphorus (TP) in the St. Clair River have reflected declines in Lake Huron. We demonstrate that St. Clair River TP concentrations are higher than offshore Lake Huron values. The recent average (2014 and 2015) incoming TP load from the upstream Great Lakes is measured here to be 980 metric tonnes per annum (MTA), which is roughly three times greater than previous estimates. Significant TP load increases are also indicated along the St. Clair River. We treat the lower Detroit River as three channels to sample water quality as part of a two year monitoring campaign that included winter sampling and SRP in the parameter suite. We found concentrations of many parameters are higher near the shorelines, with the main Mid-River channel resembling water quality upstream measured at the mouth of the St. Clair River. Comparison with past estimates indicates both concentrations and loadings of TP have dramatically declined since 2007 in the Trenton Channel, while those in the Mid-River and in the Amherstburg Channel have remained similar or have possibly increased. The data demonstrate that the TP load exiting the mouth of the Detroit River into Lake Erie is currently in the range of 3740 (in 2014) to 2610 (2015) MTA.     

Zooplankton sampling in large riverine systems: A gear comparison

Large river systems create challenges when sampling zooplankton. The dynamics of large rivers, spatial heterogeneity of biota, and behaviours of zooplankton can all contribute to large variation in estimation. The gear utilized for zooplankton collections may also be a factor, and there is not a well‐studied gear, nor industry standard, for collection in riverine systems. The lack of consistent sampling methods makes it difficult to compare zooplankton within and across systems. A standard method for zooplankton collection would be valuable for comparison among studies. To optimize zooplankton assessment in large river habitats, we tested how community estimations varied between four common zooplankton sampling devices across three river habitat types. We tested four gears: the Schindler–Patalas trap, integrated tube sampler, powered water pump, and horizontal tow net. Each device was used to collect samples in thalweg, channel border, and backwater river habitats within Pool 8 of the Upper Mississippi River in June, July, and August of 2017. Our results support that there are qualitative and quantitative differences in zooplankton estimates among gear in different habitats. The powered pump most often yielded highest abundances of total and individual zooplankton taxa allowing for more reliable community comparisons. With some modification, the pump is recommended as the most appropriate sampling gear when performing quantitative studies of zooplankton composition and abundance in large river habitats.     

分汊型河道水流运动特性和污染物输移规律研究进展

对分汊型河道的水流运动特性和污染物输移扩散规律的相关研究进行综述,分别从分汊型河道中分汊口、交汇口、整个分汊河道的水流特性及分汊型河道中的污染物输移特性等4个方面进行总结。介绍分汊口和交汇口处的水流从其能量损失、水位变化、水流分离等一维、二维过流特征到三维流动结构和紊动特性的研究过程;从野外现场试验、室内物理模型试验和数学模型模拟等角度出发阐述了整个分汊河道的水流特性;认为污染物在分汊河道中的输运规律研究主要集中在数值模拟上,并进行了回顾和分析;提出分汊河道水流水质输移特性研究中一些有待深入探究的问题,尤其亟待加强不同排放方式、不同污染物密度和不同分汊形态下污染物输移机制的试验研究。     

Modelling Effects of Remedial Programs to Aid Great Lakes Environmental Management

Computer simulation of remedial programs was carried out employing a large and diverse information base on both point and nonpoint pollutant sources in the Great Lakes basin to provide a more holistic environmental management perspective. The process utilizes a cascading system of sub-basin unit area pollutant loads (classified by land use and land form), per capita municipal pollutant inputs, river transmission factors, and remedial program effectiveness, in terms of reduced loadings to the lakes and costs. It was employed by PLUARG (Pollution from Land Use Activities Reference Group) to determine scenarios of remedial programs which apparently were practicable and would achieve target lake loads of phosphorus most cost-effectively. The analysis, presented here for Lake Erie, Lake Ontario, and southern Lake Huron, provides a means of evaluating the effectiveness of various remedial program options to fulfill commitments by Canada and the United States to load reductions for these lakes. The methodology can be extended to other pollutants as sufficient data become available to permit a suitable degree of resolution for management decisions.     

Lake Erie Central Basin Total Phosphorus Trend Analysis from 1968 to 1982

The total phosphorus data from 1968 to 1982 in the Lake Erie central basin trend study area was analyzed to determine in-lake responses to the Great Lakes Water Quality Agreement (GLWQA) phosphorus loading reduction program. The available data for each year were divided into five subsets according to time of year and depth of the water column. Each data subset was regressed as a function of time and total phosphorus loadings to Lake Erie. Linear regression analysis indicates that the in-lake phosphorus concentrations have been decreasing and are well correlated with decreased loadings to the lake. The highest rate of phosphorus decrease with time (0.56 ± 0.10 mg · m⁻³ yr⁻¹) was obtained by using epilimnetic concentrations from April to December for each year. This data subset also shows the best correlation with decreasing phosphorus loadings. From 1968 to 1982, Lake Erie offshore phosphorus concentrations responded to decreasing external phosphorus loadings at a rate of 0.45 ± 0.09 mg · m⁻³ per thousand metric tonnes.     

Pollutant loadings generated by nonpoint sources in the Santa Monica Bay Drainage Basin: A case study

The Santa Monica Bay provides a number of beneficial uses. To protect these, best management practices that control urban runoff should be utilized. In order to determine the types of best management practices to be used, an estimation of nonpoint source pollutant loads generated by the Santa Monica Drainage Basin is needed. Local land use, runoff, and chemical data were used to estimate pollutant loads from nonpoint source pollution and pollutant loads by land use in three subbasins of the Santa Monica Drainage Basin: namely, Ballona Creek, Malibu Creek, and Topanga Creek. The time period of available data was May 1988 to May 1990.The study found that (1) nonpoint source pollutant loads may be derived from local data, (2) pollutant loads by land use could not be derived because of lack of data, (3) an evaluation of seasonal pollutant loads fails to show significant trends.It is possible to evaluate pollutant loads that need control by best management practices in the Santa Monica Bay Drainage Basin by utilizing the pollutant load estimates of this study with pollutant impacts to beneficial uses.     

基于数据同化校正参数的河流磷迁移估计研究

通过磷迁移数学模型合理估计磷在河流中的时空分布,对防治水体富营养化,抑制水华暴发具有重要的科学和工程意义。数据同化方法可以将模型和观测两种研究手段有机地结合起来,将观测数据融入模型,优化模型状态变量,校正模型参数,进而提高数学模型的模拟预报精度,并依托物联网技术将传统数学模型发展为实时数学模型。本文将粒子滤波数据同化算法引入到水动力-泥沙-磷迁移模型中,以实测的断面磷含量作为观测数据,在观测时刻优化磷含量估计结果,同时校正模型参数磷相平衡分配系数Kd,构建了水动力-泥沙-磷迁移模型同化系统。将其应用于长江上游寸滩至坝前河段的计算结果表明,所构建的同化系统在真实的河流中计算效果良好,可以有效地优化更新状态变量各相磷含量浓度,并反演出模型参数Kd随水沙水环境条件变化的动态变化过程,同化之后模型模拟预报磷输移过程的精度显著提升,为水质实时模型打下基础。