Effectiveness of ferrate (VI) preoxidation in enhancing the coagulation of surface waters

Standard jar tests were conducted to evaluate the effectiveness of ferrate preoxidation in enhancing the coagulation of surface waters. A substantial reduction of residual turbidity after sedimentation and filtration was achieved by ferrate preoxidation in all cases of the investigation of various water qualities at low ferrate dosage (0.5–1.0 mg/l). The enhancement of the coagulation was more obvious when the organic content in the waters were relatively high.     

智能浑浊度检测装置的研制

本文介绍了一种应用红外光电传感原理并通过单片机实现对液体浑浊度的在线检测、数据处理和反馈控制信息的智能浑浊度检测装置。分析了本装置的设计思想、阐述了软硬件的基本结构。     

配水管网中水质变化规律及主要影响因素分析

安全输配是饮用水水质保障的关键。在对中国南方 S 市配水管网水质大量调查的基础上,分析了余氯、浊度、铁、三卤甲烷、卤乙酸、AOC 等主要水质指标在管网中的变化规律,发现余氯沿管线逐渐降低,浊度和铁基本沿管线逐渐增加,其主要影响因素有管道属性、温度及水力条件等;三卤甲烷在管网中表现出增加的趋势,而卤乙酸则在管网中表现出降低的趋势,其主要影响因素有余氯浓度、水质条件、温度条件及水力条件等;供水系统中 AOC 以 AOC-P17为主要组分,沿供水系统有逐渐增加的趋势,其浓度、组成以及在管网中的变化规律呈现明显的季节性。     

Turbidity study of solar ponds utilizing seawater as salt source

A series of experiments were conducted to study the turbidity reduction in solar ponds utilizing seawater as salt source. The experiment on the turbidity reduction efficiency with chemicals indicates that alum (KAl(SO₄)₂·12H₂O) has a better turbidity control property because of its strongly flocculating and also well depressing the growing of algae and bacteria in the seawater. In comparison with bittern and seawater, our experiment shows that the residual brine after desalination can keep limpidity for a long time even without any chemical in it. Experiments were also conducted on the diffusion of turbidity and salinity, which show that the turbidity did not diffuse upwards in the solution. In the experiment on subsidence of soil in the bittern and saline with the same salinity, it was found that soil subsided quite quickly in the pure saline water, but very slowly in the bittern. In this paper we also proposed an economical method to protect the solar pond from the damage of rain. Finally, thermal performance of a solar pond was simulated in the conditions of different turbidities using a thermal diffusion model.     

Effects of porous media on thermal and salt diffusion of solar pond

Laboratory and field experiments were carried out along with numerical simulations in this paper to study the effects of porous media on thermal and salt diffusion of the solar ponds. From our laboratory experiments simulating heat transfer inside a solar pond, it is shown that the addition of porous media to the bottom of a solar pond could help enhance its heat insulation effect. The experiment on salt diffusion indicates that the upward diffusion of the salt is slowed down when the porous media are added, which helps maintain the salt gradient. Our field experiments on two small-scaled solar ponds indicate that when porous media are added, the temperature in the lower convective zone (LCZ) of the solar pond is increased. It is also found that the increase in turbidity is repressed by porous media during the replenishment of the salt to the LCZ. Thermal diffusivities and conductivities of brine layers with porous media such as pebble and slag were also respectively measured in this paper based on the unsteady heat conducting principles of a semi-infinite body. These measured thermal properties were then used in our numerical simulations on the effect of porous media on thermal performance of a solar pond. Our simulation results show that brine layer with porous media plays more positive role in heat insulation effect when thermal conductivity of the ground is big. On the other hand, when the ground has a very small thermal conductivity, the performance of solar pond might be deteriorated and total heat storage quantity of solar pond might be reduced by brine layer with porous media.     

Novel Pragmatic Turbidimetric Data Analysis Method for Evaluating the Stability of Emulsions

A novel pragmatic turbidimetric data analysis method for evaluating emulsion stability by using a spectrophotometer is proposed. An overview of this method is shown in a flowchart. The advantage of this method is that it uses change in turbidity against time, which allows it to be applied to all emulsions and food scientists to easily calculate half-life time. A high half-life time shows that turbidity is decreased slowly and that the emulsion state can be kept for a long time. Due to this simplicity, it is hoped that this will become a commonly used method.     

采用浊度法检测聚丙烯酰胺

采用浊度法检测聚丙烯酰胺(HPAM)的质量浓度,考察了反应时间、波长、温度及矿化度对吸光度的影响。实验结果发现:最佳测试条件为反应时间25 min,波长472 nm,温度18～25℃;一价金属离子Na+,K+和二价金属离子Mg2+,Ca2+对测试结果基本无影响,而三价Al3+对吸光度有很大的影响,当ρ(Al3+)大于80 mg/L时,吸光度值趋于稳定。在最佳测试条件下,绘制不同水质条件下不同ρ(HPAM)的标准曲线,发现水质不同,对吸光度的影响不同,矿化度越高吸光度的变化值越大。因此,在检测油田注入、采出液中ρ(HPAM)时,可通过模拟实测水样配制反应体系溶液进行测定。研究表明,用浊度法检测ρ(HPAM)范围宽、精确度高、重现性好。     

编解码电路在遥测遥控系统中的应用

本文介绍了一种新颖的编解码芯片的工作原理,给出了一个应用实例,讨论了ＵＭ３７５８－１０８在浑水浊度测控系统中的应用,最后给出了实验结果。     

Turbidity dynamics during spring storm events in an urban headwater river system: the Upper Tame, West Midlands, UK

Turbidity is an important water quality variable, through its relation to light suppression, BOD impact, sediment-associated contaminant transport, and suspended sediment effects on organisms and habitats. Yet few published field investigations of wet-weather turbidity dynamics, through several individual and sequenced rainstorms in extremely urbanised headwater basins, have emerged. This paper aims to address this gap through a turbidity analysis of multiple storm events in spring 2001 in an urban headwater basin (57 km2) of the River Tame, central England, the most urbanised basin for its size in the UK ( approximately 42%). Data were collected at 15-min frequency at automated monitoring stations for rainfall, streamflow and six water quality variables (turbidity, EC, temperature, DO, pH, ammonia). Disturbance experiments also allowed estimates of bed sediment storage to be obtained. Six important and unusual features of the storm event turbidity response were apparent: (1) sluggish early turbidity response, followed by a turbidity 'rush'; (2) quasi-coincident flow and turbidity peaks; (3) anti-clockwise hysteresis in the discharge-turbidity relationship on all but one event, resulting from Falling-LImb Turbidity Extensions (FLITEs); (4) increases in peak turbidity levels through storm sequences; (5) initial micro-pulses (IMP) in turbidity; and (6) secondary turbidity peaks (STP) or 'turbidity shoulders' (TS). These features provided very little evidence of a true 'first-flush' effect: instead, substantial suspended solids transport continued right through the flow recessions, and little storm-event sediment exhaustion was evident. A new, dimensionless, hysteresis index, HI(mid), is developed to quantify the magnitude and direction of hysteresis in a simple, clear, direct and intuitive manner. This allowed the degree of departure from the classic 'first-flush', clockwise hysteresis models to be assessed. Of the 15 turbidity events considered, 10 coincided with ammonia spikes of up to 6.25 mg l(-1) at Water Orton (the downstream station): this suggests that spills from combined sewer overflows (CSO) or waste water treatment works (WwTWs) are significant in the throughput of turbid waters here. Substantial ammonia peaks related most strongly to total storm rainfall receipt, of four rainfall variables considered, and significant ammonia peaks were generated even from low-magnitude storms (rainfall totals <4 mm), indicating that spills are a frequent occurrence. Local bed sediment stores appear to be limited, suggesting that other distal sediment sources, such as road networks and old mineworkings are possibly more important. Biofilms may also play a part in delaying sediment release until late in the hydrograph, and in suppressing late spring turbidity levels. Existing first-flush models appear to be an oversimplification here. Such urban headwater basin responses can provide useful insights into the generation of contaminant waves, and offer vital early-warning systems for pollution events propagating downstream.     

You can’t just use gold: Elevated turbidity alters successful lure color for recreational Walleye fishing

Increasing anthropogenic turbidity alters underwater visual environments, leading to disrupted perception of visual cues with a variety of consequences, such as diet shifts and reduced prey consumption. In this study, we used novel techniques, including a citizen science mobile phone application (app), to investigate the effects of altered water clarity on recreational fisheries. Our objectives were to determine if elevated turbidity (suspended sediments or algae) alters lure success in the recreational Walleye (Sander vitreus) fishery and if the behavior of recreational anglers shifts with algal blooms. We developed a mobile phone app to gather real time data on lure success across water clarity conditions in collaboration with Lake Erie charter captains. Citizen science data collected with the app showed that lure color success shifted with water color and clarity: white lures were most successful in clear water, yellow in sedimentary turbidity, and black in algal conditions. A survey of charter captains suggested that fishing practices and lure usage may change over the long term if algal blooms persist.