A study of water quality in an urban river and potential improvement using a prototype instream aerator

1989 ◽  
Vol 16 (3) ◽  
pp. 308-316 ◽  
Author(s):  
C. A. Town ◽  
D. S. Mavinic ◽  
B. Moore
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Data Base ◽  
Chlorophyll A ◽  
Late Summer ◽  
Urban River ◽  
Agricultural Activity ◽  
Fish Kills ◽  
Low Dissolved Oxygen ◽  
Oxygen Levels

Urban encroachment and intensive agricultural activity within the Serpentine–Nicomekl watershed (near Vancouver, B.C.) have caused a series of fish (salmon) kills on the Serpentine River since 1980. Low dissolved oxygen was responsible for these kills. This field project investigated some of the dynamic chemical and biological relationships within the river, as well as the use of an instream aerator as a temporary, in situ, water quality improvement measure. Weekly sampling for a 6-month period during the latter half of 1985 established a solid data base for deriving and interpreting meaningful interrelationships. A strong correlation between chlorophyll a and dissolved oxygen levels before the algae die-off supported the hypothesis that algae blooms dying in the fall could create a serious oxygen demand. Because of these environmental conditions, the river is unable to sustain healthy dissolved oxygen levels during this period. As such, a prototype, 460 m artificial aeration line was designed, installed, and monitored to evaluate its potential for alleviating low dissolved oxygen conditions and improving overall water quality during the critical fall period.The instream aerator ran continuously for over 2 months, starting in September 1985. Despite better-than-expected weather conditions (i.e., cool, wet weather) and relatively high dissolved oxygen levels during the fall of 1985, the data base appeared to support the use of this prototype aeration unit as a means of "upgrading" a stretch of an urban river subject to periodic, low dissolved oxygen levels. As a result, a 2-year follow-up study and river monitoring was initiated. In both 1986 and 1987, late summer and early fall river conditions resulted in the potential for serious salmon kills, due to higher-than-normal river temperatures and very low dissolved oxygen. In both instances, the instream aerator prevented such fish kills in a key stretch of the river. Expansion of the system to include other critical stretches of the Serpentine and other urban river systems, near Vancouver, is being considered. Key words: algae, aerator, chlorophyll a, eutrophic, fish kills, instream aeration, river improvement, urban river.

scholarly journals SISTEM FUZZY PADA KONTROLING AERATOR UNTUK MENINGKATKAN KUALITAS AIR KOLAM PEMBIBITAN IKAN MENGGUNAKAN SENSOR DO DAN SENSOR SUHU

2021 ◽  
Vol 8 (1) ◽  
pp. 39
Author(s):  
Andi Farmadi ◽  
Muliadi Muliadi
Keyword(s):  
Water Quality ◽  
Control System ◽  
Dissolved Oxygen ◽  
Continuous Control ◽  
Engine Control ◽  
Inference System ◽  
Analysis And Design ◽  
Oxygen Levels ◽  
Engine Control System ◽  
Smart Machine

<p><em>Dissolved oxygen levels in water will affect water quality directly and indirectly for fish life as well as conditions in the water environment, therefore, it is very important to control water quality for adequate dissolved oxygen levels, because this plays an important role in the health condition of the environmental ecosystem for fish nurseries. Researchers usually measure and monitor water quality using measuring instruments that are widely sold in the market, for conditions of decreasing dissolved oxygen levels in fish nurseries tank can usually be controlled by adding an air bubble machine to the water using an aerator machine. Giving air bubbles to water is an effort to control the conditions for the adequacy of dissolved oxygen in the water, and the best system is to carry out a continuous control system regarding water quality, sometimes the oxygen condition in the water is sufficient for the standard of dissolved oxygen in water. However, the blower blower is still running, this is less effective because it requires unnecessary electrical energy or wastes energy. Analysis of the aerator engine control system is needed to make a design as to what state the aerator engine should be turned on. Analysis of the aerator engine control system can be done by measuring the level of oxygen and water temperature in the fish nursery tank, then designing a fuzzy model with the Sugeno inference system for how long the engine must be turned on. The analysis and design of this aerator system is a proposed solution to these problems with a system of measurement and monitoring carried out intelligently by a machine, so that it is able to measure how late this aerator machine must be turned on. and the developed design is capable of being a smart machine using a fuzzy system</em></p><p><strong><em>Keywords</em></strong><em>: Fuzzy inference, aerator engine, smart system, water quality.</em></p><p><em>Kadar oksigen terlarut dalam air akan mempengaruhi kualitas air secara langsung dan tidak langsung bagi kehidupan ikan juga keadaan di lingkungan air tersebut, oleh karena itu peningkatan kualitas air untuk keadaan kecukupan kadar oksigen yang terlarut sangat penting untuk dikontrol, karena hal ini berperan penting pada kondisi kesehatan ekosistem lingkungan pembibitan ikan. </em><em>Para peneliti biasanya melakukan pengukuran dan pemantauan kualitas air dengan menggunakan alat ukur yang banyak di jual dipasaran, untuk kondisi menurunnya kadar oksigen yang terlarut pada kolam pembibitan ikan biasanya dapat di kontrol dengan menambahkan mesin gelembung udara pada air menggunakan mesin aerator. Pemberian gelembung udara pada air merupakan salah satu upaya untuk mengontrol kondisi kecukupan kadar oksigen yang terlarut di dalam air, dan sistem yang terbaik yaitu melakukan sistem kontrol secara terus menerus mengenai kualitas air, terkadang kondisi oksigen di dalam air telah mencukupi standar kecukupan oksigen terlarut pada air, namun mesin penyembur gelembung udara masih dinyalakan, hal ini menjadi kurang efektif sebab akan membutuhkan energi listrik yang tidak semestinya atau terjadinya pemborosan energi. Analisis sistem pengontrolan mesin aerator dibutuhkan untuk melakukan desain seperti apa sebaiknya keadaan mesin aerator dihidupkan. Analisis sistem pengontrolan mesin aerator ini dapat dilakan dengan mengukur tingkat kadar oksigen dan suhu air pada kolam pembibitan ikan, kemudian melakukan perancangan model fuzzy dengan sistem inferensi sugeno seberapa lama mesin harus dihidupkan. Analisis dan desain sistem aerator ini merupakan usulan solusi permasalahan tersebut dengan sistem pengukuran dan pemantauan dilakukan secara cerdas oleh mesin, sehingga mampu mengukur seberapa lalma mesin aerator ini harus dihidupkan desain alat ini juga diharapkan mampu memberikan solusi peningkatan kualitas air pada pembibitan ikan dan diharapan pula analisis dan desain yang dikembangkan ini mampu menjadi mesin cerdas dengan menggukan sistem fuzzy</em></p><p><strong><em>Kata kunci</em></strong><em> : Fuzzy inferensi, mesin aerator, Sistem cerdas, kualitas air.</em></p>

scholarly journals Fish Rescue during Streamflow Intermittency May Not Be Effective for Conservation of Rio Grande Silvery Minnow

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3371
Author(s):  
Thomas P. Archdeacon ◽  
Tracy A. Diver ◽  
Justin K. Reale
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Fish Assemblages ◽  
Sublethal Effects ◽  
Rio Grande ◽  
Quality Data ◽  
Water Quality Data ◽  
Low Dissolved Oxygen ◽  
Rio Grande Silvery Minnow ◽  
Oxygen Concentrations

Streamflow intermittency can reshape fish assemblages and present challenges to recovery of imperiled species. During streamflow intermittency, fish can be subjected to a variety of stressors, including exposure to crowding, high water temperatures, and low dissolved oxygen, resulting in sublethal effects or mortality. Rescue of fishes is often used as a conservation tool to mitigate the negative impacts of streamflow intermittency. The effectiveness of such actions is rarely evaluated. Here, we use multi-year water quality data collected from isolated pools during rescue of Rio Grande silvery minnow Hybognathus amarus, an endangered minnow. We examined seasonal and diel water quality patterns to determine if fishes are exposed to sublethal and critical water temperatures or dissolved oxygen concentrations during streamflow intermittency. Further, we determined survival of rescued Rio Grande silvery minnow for 3–5 weeks post-rescue. We found that isolated pool temperatures were much warmer (>40 °C in some pools) compared to upstream perennial flows, and had larger diel fluctuations, >10 °C compared to ~5 °C, and many pools had critically low dissolved oxygen concentrations. Survival of fish rescued from isolated pools during warmer months was <10%. Reactive conservation actions such as fish rescue are often costly, and in the case of Rio Grande silvery minnow, likely ineffective. Effective conservation of fishes threatened by streamflow intermittency should focus on restoring natural flow regimes that restore the natural processes under which fishes evolved.

scholarly journals Optimization of water flushing in lowland urban river in Jiaxing, Zhejiang using dissolved oxygen as the indicator

2018 ◽  
Vol 246 ◽  
pp. 02048
Author(s):  
Peiying Tan ◽  
David Z. Zhu ◽  
Yiping Zhang ◽  
Yongchao Zhou
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Urban River ◽  
Saturation Level ◽  
Evaluation Index ◽  
Urban Rivers ◽  
Time Intervals ◽  
Exponential Relationship ◽  
Do Concentration

River flushing has been considered as an effective tool for improving water quality in heavily polluted urban rivers. Dissolved oxygen (DO) as the evaluation index of water quality varied with time during and after water flushing. The time intervals between the flushing should be optimized such that the DO concentration remains above 2mg/L in the river. The duration between the flushing was found to be mainly correlated to the water temperature and the saturation level of dissolved oxygen. For the study river, when the temperature was below 15 ℃, there was an exponential relationship between the duration and saturation level of DO. For instance, the estimated duration was 157 hours or about 7 days for the subsequent flushing when the saturation level of DO was 90%. This duration was no more than 2 days when the temperature was above 15 ℃.

Some Effects of Temporary Exposure to Low Dissolved Oxygen Levels on Pacific Salmon Eggs

1958 ◽  
Vol 15 (2) ◽  
pp. 229-250 ◽  
Author(s):  
D. F. Alderdice ◽  
W. P. Wickett ◽  
J. R. Brett
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Oxygen Demand ◽  
Oxygen Availability ◽  
Oncorhynchus Keta ◽  
Hatching Rate ◽  
Oxygen Level ◽  
Low Oxygen ◽  
Low Dissolved Oxygen ◽  
Oxygen Levels

Eggs of the chum salmon (Oncorhynchus keta) were exposed to various constant levels of dissolved oxygen for a period of seven days. The procedure was repeated with fresh egg samples at various developmental stages. Temperatures were constant at 10 °C. from fertilization to hatching. Estimates of oxygen consumption uninhibited by low dissolved oxygen levels were obtained at various stages of egg development for whole eggs and also on the basis of the weight of larvae, excluding the yolk. Eggs were most sensitive to hypoxia between 100–200 Centigrade degree-days and compensated for reduced oxygen availability by reducing the oxygen demand and rate of development. Very low oxygen levels at early incubation stages resulted in the production of monstrosities. At about the time the circulatory system becomes functional the compensatory reduction in rate of growth under hypoxial conditions is reduced, but eggs no longer survive extreme hypoxial conditions. Eggs subjected to low dissolved oxygen levels just prior to hatching hatch prematurely at a rate dependent on the degree of hypoxia. The maximum premature hatching rate corresponded approximately with the median lethal oxygen level. Estimated median lethal levels rose slowly from fertilization to hatching. Oxygen consumption per egg rose from fertilization to hatching while the consumption per gram of larval tissue declined from a high to a low level at about the time of blastopore closure. Subsequently, a slight rise in the rate occurred up to a level which was more or less constant to hatching. "Critical" dissolved oxygen levels were calculated and they appear to define the oxygen level above which respiratory rate is unmodified by oxygen availability. Critical levels ranged from about 1 p.p.m. in early stages to over 7 p.p.m. shortly before hatching.

scholarly journals Water quality changes in floodplain lakes due to the Amazon River flood pulse: Lago Grande de Curuaí (Pará)

2011 ◽  
Vol 71 (3) ◽  
pp. 601-610 ◽  
Author(s):  
AG Affonso ◽  
C. Barbosa ◽  
EMLM. Novo
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Chlorophyll A ◽  
Water Use ◽  
Flood Pulse ◽  
Human Consumption ◽  
Trophic State Index ◽  
Amazon Floodplain ◽  
Marginal Areas ◽  
State Index

Assurance of water quality for human consumption is essential for public health policies. In the Amazon floodplain, the seasonal water level variation causes periodic flooding of marginal areas that are usually used for settlements, agriculture and livestock. Therefore, the exchange of materials between the terrestrial and aquatic ecosystem affects the proportion of suspended and dissolved components in water and its physical-chemical characteristics, and consequently the quality of the water used by local people. Following this approach, the aim of this study is to evaluate changes in water quality in Lago Grande de Curuaí floodplain, Óbidos, Pará in response to the flood pulse, during one hydrological year from 2003 to 2004, based on water use classes (according to National Water Agency 357/2005 resolution) using chlorophyll-a and dissolved oxygen concentration as parameters and the eutrophication index. Ordinary kriging was applied to interpolate chlorophyll-a and dissolved oxygen and to predict values at non sampled locations. Each location was then classified according to water use acceptable parameters and to Carlson Trophic State Index modified by Toledo to map lake water classes and trophic status. The result showed that Lago Grande de Curuaí floodplain is a supereutrophic system, with levels of dissolved oxygen and chlorophyll-a not suitable for human supply during the receding water phase. These areas are located near the riverine communities, which can cause health problems due to the presence of potentially toxic algae. Therefore, monitoring water quality in Amazon lakes is essential to ensure the availability has appropriate quality for human and animal supplies.

scholarly journals Lithuanian karst region rivers' water ecology: hydrochemical and hydrobiological evaluation

2004 ◽  
Vol 35 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Rimvydas Tumas
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Point Sources ◽  
Biotic Index ◽  
Karst Region ◽  
Agricultural Activity ◽  
Nitrogen And Phosphorus ◽  
Stream Pollution ◽  
Biological Water ◽  
Biological Water Quality

The Lithuanian karst region covers about 1000 km3 in the northern part of the country. This is the most vulnerable area from a pollution point of view. The structure of the total dissolved solids (TDS) shows that the flow of rivers in the karst region is from hydraulically interconnected aquifers. For the last decade (1991–2000) TDS has varied considerably, from 529 to 732 mg/l. The predominant sources of nitrogen and phosphorus within the headwaters of the monitored rivers were diffuse and agricultural in nature. Downstream from the towns nitrogen and especially phosphorus showed both diffuse and point source signals. Contributions of point sources to the stream pollution by nutrients prevail. The time series of monthly dissolved oxygen (O2) in the main karst region river – the Musa – shows the existence of multiplicative seasonality. The trend cycle (1991–1999) shows low levels of dissolved oxygen in 1991–1993, with a similar fluctuation in 1994, 1995 and 1996 (due to point pollution from the town of Siauliai) and a gradually improving situation since 1997. The general multiplicative trend of dissolved oxygen in the lower reaches of the Musa river (near the border with Latvia) is decreasing (within the accuracy limits). The abundance and species of zoo benthos are suitable criteria (biotic index – BI) for evaluation of a river's biological water quality. Zoo benthos demonstrates tolerances that vary among species, the oxygen regime and the pollution with nitrogen. The best living conditions for invertebrates are in the riverhead of the karst region rivers – BI=5.62–6.74 (1991–1999), where pollution with nutrients is caused mostly by agricultural activity. Rare and asynchronous data of biological water quality shows up tendencies that invertebrates prefer less contaminated reaches of rivers.

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