提高循环水浓缩倍数节水减排方案探讨

针对川西北某轻烃厂循环冷却水水质的特点,拟采用无磷药剂配方将循环水浓缩倍数从3．0提高到5．0,并新增软水处理系统作为循环水补水,从而达到优化水质、节水减排的目的。针对浓缩倍数提高引起得的水质稳定难题提出相应的技术方案,最终达到改善水质,保护水环境,节水减排的效果。     

降低循环冷却水水耗的生产措施

为了有效降低循环冷却水系统补充水量、排污量,节约水处理剂的消耗、降低冷却水处理成本,关键在于提高循环水的浓缩倍数。本文对影响循环水浓缩倍数的因素进行了分析,总结了哈尔滨石化公司循环水场存在的问题。同时本文给出了提高循环水浓缩倍数的方法,上述方法能取得显著的环境效益和经济效益。     

选矿厂尾矿水零排放及三水自控平衡

本钢歪头山铁矿利用浓缩能力富余的特点，采用絮凝浓缩工艺对污水进行回收。尾矿浓缩机提高底流浓度及计算机集散优化控制，尾矿库静压回水远程自动控制，实现了尾矿输送单运行、三水平衡自动控制和尾矿水零排放，投资省，见效快，效益好。     

新疆主要湖泊,水库的水质综合特征评价模式及灰色预测分析

为了解新疆湖、库的水质现状，采用水质综合评价模式对新疆主要湖、库水质现状给出了适应《地面水环境质量标准》ＧＢ３８３８－８８为标准的水质综合特征模式。该模式给出的信息量大，表达直观，不仅能给出各水质参数的水域类别，划分水域类别的依据参数，还能给出超Ｖ类水域的水质参数的超标倍数。在现状评价基础上，利用灰色系统理论对污染湖、库的主要污染参数进行了预测分析。     

镇江市新区第二污水厂水质水量平衡分析研究

本文针对厂外泵站和厂区进水水质水量不一致现象以及污水厂出水NH3-N指标较高的问题,进行了污水厂外泵站和厂区进水水质水量平衡与污水厂内氮平衡的分析研究.根据研究结果,通过改进泵站取样方式,对SS较高的脱水机冲洗水进行沉淀处理以及加强对排水用户的监管后,目前该污水厂运行稳定,水质水量能够保证平衡,出水NH3-N能够稳定达标.     

含油污泥减量化处理技术探讨

油田开发生产的地面配套含油污水处理工艺中,通常采用的混凝沉降罐和自然沉降罐,以及高效沉降分离设备都需要定期排泥,同时存在如何将处理工艺中过滤设备截留的大量杂质分离出去,从而提高系统处理工艺的处理效果和处理后的水质达标率的问题。文章就上述问题通过试验和技术比较,确定了污泥杂质→污泥沉降浓缩→二相卧螺御料式离心机→外运的污泥减量化处理工艺技术,解决了含油污水处理工艺中的污泥回收问题,满足了油田生产需要,大大提高了整个污水处理工艺的效果和效率,以及水质达标率。     

熔融法处理垃圾焚烧飞灰过程中可溶盐的酸洗分离效果评估

针对垃圾焚烧飞灰中高含量的可溶盐组分钠、钾、氯会影响其资源化处置及利用的问题,利用高温熔融法处理飞灰,使原料飞灰中钠、钾、氯等可溶盐物质向烟气系统产生的3种浓缩灰中富集,并采用酸洗法对浓缩灰中上述物质进行分离,结果表明:最终产品建材基材中氯含量相比飞灰原料含量降幅58. 36%,浓缩灰(预除尘)、浓缩灰(急冷降温)、浓缩灰(布袋除尘)相比原料各成分的富集倍数分别为:钠1. 96、2. 90、5. 59倍;钾2. 17、3. 58、7. 47倍;氯3. 06、3. 93、5. 45倍,优良的富集效果为可溶盐成分回收提供了技术条件。     

濑溪河泸县段水质评价与治理建议

本文运用综合污染指数法对濑溪河泸县段天竺寺大桥和官渡大桥上、下两个断面的水质进行现状评价和污染变化规律分析,表明濑溪河泸县段污染情况逐年恶化,超标频率和倍数都成上升趋势,枯水月份、平水月份、丰水月份分别对水体污染起着不同的作用,在丰水月份来临之前、之后的平水月份非点源污染污染突出,可见濑溪河泸县段非点源污染在濑溪河的水体污染中占有一定的比重,濑溪河泸县段水质状况不容乐观,亟待加强水质污染的防治和控制力度,并提出治理的建议。     

地表水在线水质分析仪实际水样测量准确性和稳定性影响因素分析

从水样预处理、分析方法、运行维护等方面分析了地表水在线水质分析仪实际水样测量准确性和稳定性影响因素,指出只有在解决实际工作问题中多总结经验,才能提高环境水质自动监测技术水平。     

嘉陵江南充段水质监测分析与综合评价

本文依据南充市2011年~2013年嘉陵江流域水环境监测统计资料,采用单因子评价法和综合污染指数法分析与综合评价嘉陵江南充段水质污染特征和现状。结果表明,研究河段内的清泉寺、小渡口和李渡断面总氮含量超标属于地表水Ⅳ类水体,超标倍数年均值分别0.21、0.35、0.37,其他监测项目符合Ⅲ类水质标准,均属于轻度污染。彩虹桥断面总氮、总磷、氨氮、CODMn和BOD5含量超过Ⅲ类标准,均在Ⅳ~Ⅴ类范围,属于中度污染。综合分析嘉陵江南充段,水质主要污染指标为总氮,综合污染指数为0.38,水质综合评价结果属轻度污染。该评价结果能为嘉陵江流域的水环境保护和科学治理提供依据。     

Ecosystem Modeling Applied to Nutrient Criteria Development in Rivers

Threshold concentrations for biological impairment by nutrients are difficult to quantify in lotic systems, yet States and Tribes in the United States are charged with developing water quality criteria to protect these ecosystems from excessive enrichment. The analysis described in this article explores the use of the ecosystem model AQUATOX to investigate impairment thresholds keyed to biological indexes that can be simulated. The indexes selected for this exercise include percentage cyanobacterial biomass of sestonic algae, and benthic chlorophyll a. The calibrated model was used to analyze responses of these indexes to concurrent reductions in phosphorus, nitrogen, and suspended sediment in an enriched upper Midwestern river. Results suggest that the indexes would respond strongly to changes in phosphorus and suspended sediment, and less strongly to changes in nitrogen concentration. Using simulated concurrent reductions in all three water quality constituents, a total phosphorus concentration of 0.1 mg/l was identified as a threshold concentration, and therefore a hypothetical water quality criterion, for prevention of both excessive periphyton growth and sestonic cyanobacterial blooms. This kind of analysis is suggested as a way to evaluate multiple contrasting impacts of hypothetical nutrient and sediment reductions and to define nutrient criteria or target concentrations that balance multiple management objectives concurrently. Any opinions, findings, conclusions, or recommendations expressed in this article are those of the authors alone, and do not necessarily reflect the views of the U.S. Environmental Protection Agency or of the U.S. Government.     

DIGITAL SIMULATION OF THE EFFECT OF THERMAL DISCHARGE ON STREAM WATER QUALITY1

A modified transient version of the Streeter-Phelps model along with the energy balance equation is employed to analyze the effects of waste heat discharge from power plants on stream water quality. Analysis is also made to examine the effects of the upstream water quality and stream velocity on the downstream DO concentration level. The resulting coupled nonlinear hyperbolic partial differential equations representing the energy, BOD and DO concentrations are solved by the method of characteristics and simulated on a digital computer. Final numerical results indicate that the allowable quantity of thermal discharge does heavily depend on the upstream quality.     

TEMPORAL VARIABILITY OF WATER QUALITY IN THE ST. LUCIE ESTUARY,SOUTH FLORIDA1

ABSTRACT: Four years of monthly freshwater discharge and constituent concentration data from three tributaries were related to a concurrent series of data for three segments of the St. Lucie Estuary in South Florida using multiple regression and time-series analysis techniques. Water quality parameters examined were dissolved inorganic and total nitrogen and phosphorus, chlorophyll a, total suspended solids, turbidity, and color. On monthly time scales, a multiple regression, which included freshwater discharge, freshwater constituent concentration, and dilution with ocean water (salinity) as independent variables, explained 50 percent or less of the variability in estuarine constituents. No single independent variable explained more variation than another. By contrast, on seasonal (wet, dry) time scales, freshwater discharge explained the bulk of variation in estuarine water quality (up to 93 percent). On monthly time scales, variability in concentrations of nutrients and other constituents may be largely controlled by processes internal to the system. At seasonal time scales, freshwater discharge appears to drive variability in most estuarine water quality parameters examined. Results indicate that management of tributary input on a seasonal basis, with the expectation of achieving seasonal concentration goals in the estuary, would have a higher probability of success than managing on a monthly basis.     

A process integration approach to industrial water conservation: a case study for a Chinese steel plant

A systematic approach to optimizing water network has traditionally been utilized to exam and plan water conservation in industrial processes. In the present case study, water-pinch technology was used to analyze and optimize the water network of a steel plant near China's Zhangjiakou city. A system design was developed and a limiting constraint (Cl(-) concentration) was identified based on investigations of water quality then the minimum freshwater and wastewater targets were determined without considering water losses. The analysis was then extended by calculating the additional input of freshwater required to balance the actual water losses. A nearest-neighbor algorithm (NNA) was used to distribute the freshwater and recycled water among each of the plant's operations. The results showed that with some reconstruction of the water network, the flow rates of freshwater and wastewater could be decreased by 57.5% and 81.9%, respectively.     

Interaction and influence of two creeks on Escherichia coli concentrations of nearby beaches: exploration of predictability and mechanisms

The impact of river outfalls on beach water quality depends on numerous interacting factors. The delivery of contaminants by multiple creeks greatly complicates understanding of the source contributions, especially when pollution might originate up- or down-coast of beaches. We studied two beaches along Lake Michigan that are located between two creek outfalls to determine the hydrometeorologic factors influencing near-shore microbiologic water quality and the relative impact of the creeks. The creeks continuously delivered water with high concentrations of Escherichia coli to Lake Michigan, and the direction of transport of these bacteria was affected by current direction. Current direction reversals were associated with elevated E. coli concentrations at Central Avenue beach. Rainfall, barometric pressure, wave height, wave period, and creek specific conductance were significantly related to E. coli concentration at the beaches and were the parameters used in predictive models that best described E. coli variation at the two beaches. Multiple inputs to numerous beaches complicates the analysis and understanding of the relative relationship of sources but affords opportunities for showing how these complex creek inputs might interact to yield collective or individual effects on beach water quality.     

Identifying rainfall effects in an arid Gulf of California coastal lagoon

At Ensenada de La Paz, a coastal lagoon on the western side of the Gulf of California, nutrient and salinity data before and after rain events were evaluated using a mass balance model to estimate the exchange of conservative and non-conservative variables with the adjacent sea. Surface salinity, nitrogen (N-NO3, N-NO2), and phosphorus (PO4) were used in the model to obtain the hydraulic balance, water residence time, and nitrogen and phosphorus fluxes. Results showed that residual volume was mainly influenced by evaporation. Rainfall and runoff increased the mixed volume and reduced water residence time. Pre-rainfall hydraulic balance conditions were reestablished about 10 days after a rain storm. Rainwater inputs also modified the quality of the coastal lagoon: the pre-rainfall scenario showed that more nitrogen is consumed than produced, and there is a phosphorus sufficiency. A rain disturbance induces a nitrogen and phosphorus increase. Eleven days after a rain storm, nitrogen and phosphorus levels did not return to the pre-rainfall scenario. Rain disturbances in arid zone coastal lagoons modify their water quality and exchange with the adjacent ocean; some management strategies are suggested.     

彭山岷江大桥国控监测断面水质类别变化分析

彭山岷江大桥国控断面,位于岷江干流,2010年、2011年和2012年,其水质类别分别为IV类、劣V类和劣V类,主要污染物为氨氮和总磷。本文依据其上游府河中黄龙溪断面和南河中董坝子断面水质的例行监测数据来综合分析岷江大桥水质类别变化情况。分别从评价方法、浓度、流量和通量等几方面加以阐述,结果表明,2010—2012年度,岷江大桥氨氮浓度主要受黄龙溪断面水质的影响,岷江大桥总磷的变化受到黄龙溪和董坝子水质的共同作用。     

MOBILITY AND AQUATIC TOXICITY OF COPPER IN AN URBAN WATERSHED1

ABSTRACT: Abundant use of copper based products has resulted in increased violation of copper water quality criteria in runoff from urban storm water systems. The objectives of this work were to understand the mobility and toxicity of copper in an urban watershed and to apportion the amount of copper entering the freshwater receiving stream from different urban land covers using a mass balance approach. Sixteen rainfall events collected from the University of Connecticut study watershed between August 1998 and September 2000 were analyzed to assess copper flux in an urban storm water system. Mean flow weighted dissolved copper concentrations observed in the study for copper based architectural material runoff, pervious area runoff, impervious area runoff, and in the receiving stream were 1210 ± 840, 9 ± 3, 8 ± 2, and 14 ± 7 μg/L, respectively. Mean dissolved copper concentrations in the receiving stream exceeded Connecticut's water quality criteria. Despite exceeding the dissolved concentration based criteria, cupric ion concentrations at the system outlet remained below 0.05 μg/L for all storms analyzed, and no acute toxicity (using Daphnia pulex as the test organism) was measured in samples collected from the stream.