scholarly journals Familias de agua subterránea y distribución de sólidos totales disueltos en el acuífero de La Paz Baja California Sur, México

2018 ◽  
Vol 36 (1) ◽  
pp. 39 ◽  
Author(s):  
Arturo Cruz Falcón ◽  
Enrique Troyo Diéguez ◽  
Janette M. Murillo Jiménez ◽  
José Luis García Hernández ◽  
Bernardo Murillo Amador
Keyword(s):  
Seawater Intrusion ◽  
Service Use ◽  
Monitoring Network ◽  
High Concentration ◽  
La Paz ◽  
Piper Diagram ◽  
Representative Sampling ◽  
Water Wells ◽  
Tds Concentration ◽  
Set Up

The aquifer of La Paz has been overexploited for several years, causing contamination by seawater intrusion. A well-monitoring network, which included public-urban, agricultural, livestock and service use water wells, was set up in 2013. Representative sampling during the dry and rainy seasons was carried out. Concentration of total dissolved solids (TDS), temperature, dissolved oxygen and pH were measured. Results indicate that most agricultural wells contain high TDS concentration, compared to potable water wells with concentration below 1000 mg L-1, which is the limit allowed by the Mexican official standard (MOS). Majority ion data from 14 wells near the coast with high concentration of TDS were also analyzed, with which a Piper diagram was constructed. Two main types of water were found: calcium-chloride and sodium-chloride. The presence of sodium in concentrations exceeding 200 mg L-1 in 8 wells, and magnesium with more than 50 mg L-1 in 10 wells, both above the MOS, reveal that its origin is seawater. Calcium concentrations above 250 mg L‑1 in 7 wells points to the existence of sedimentary layers of chemical-organic origin that compose the inner stratigraphy of the aquifer through which groundwater circulates. High chloride concentrations of more than 1000 mg L-1 in 6 wells with high concentration of TDS, suggests that its source is seawater intrusion. Based on the distribution of TDS concentration, two broad areas affected by seawater intrusion were delimited, and along with the distribution of water families, three main aquifer zones were identified.

scholarly journals Ground effects and hydrological changes in the Southern Apennines (Italy) in response to the 23 July 1930 earthquake (<i>M<sub>S</sub></i>=6.7)

2009 ◽  
Vol 9 (2) ◽  
pp. 539-550 ◽  
Author(s):  
E. Esposito ◽  
R. Pece ◽  
S. Porfido ◽  
G. Tranfaglia
Keyword(s):  
Monitoring Network ◽  
Water Levels ◽  
Great Earthquake ◽  
Southern Apennines ◽  
Stream Flows ◽  
Loma Prieta Earthquake ◽  
Hydrological Changes ◽  
Water Wells ◽  
Porosity And Permeability ◽  
Set Up

Abstract. The 23 July 1930 earthquake (MS=6.7) in the Southern Apennines (Italy) was a catastrophic event that produced many effects such as surface faulting, fractures, landslides, settlements, hydrological changes, variations in chemical/physical activity related to the volcanic and/or thermal zones and also acoustic and optical phenomena. It is the first great earthquake of the twentieth century that was studied, thanks to the hydrological monitoring network of the Italian Hydrographic Survey (IHS) set up from 1925 to 1929. For this earthquake we analysed the initial IHS hydrometric and pluviometric data, looking for significant anomalies in springs, water wells and mountain streams. Hydrological data relative to rivers, springs and water wells indicate that some changes can be correlated with the earthquake: a post-seismic excess discharge in some streams, pre- and co-seismic decreases in stream flows and water levels in wells, pre- and post-seismic increases in discharges. The pre- and co-seismic stresses and the tectonic deformations were studied in order to find a possible model of interaction between stress state and hydrological variations. The anomalies found in this work can be considered "rebound anomalies", which are the most common precursor reported by many authors and related to increases in porosity and permeability caused by the fracturing that precedes an earthquake. An estimation of the total excess discharge (0.035 km3) caused by the MS=6.7 Irpinia earthquake is consistent with the excess discharge of about 0.01 km3 determined for the Mw=6.9 Loma Prieta earthquake.

scholarly journals Volatility of secondary organic aerosol during OH radical induced ageing

2011 ◽  
Vol 11 (21) ◽  
pp. 11055-11067 ◽  
Author(s):  
K. Salo ◽  
M. Hallquist ◽  
Å. M. Jonsson ◽  
H. Saathoff ◽  
K.-H. Naumann ◽  
...  
Keyword(s):  
Gas Phase ◽  
Organic Aerosol ◽  
Oh Radical ◽  
High Concentration ◽  
Volatile Material ◽  
Phase Oxidation ◽  
Gas Phase Oxidation ◽  
Institute Of Technology ◽  
Set Up ◽  
Pinic Acid

Abstract. The aim of this study was to investigate oxidation of SOA formed from ozonolysis of α-pinene and limonene by hydroxyl radicals. This paper focuses on changes of particle volatility, using a Volatility Tandem DMA (VTDMA) set-up, in order to explain and elucidate the mechanism behind atmospheric ageing of the organic aerosol. The experiments were conducted at the AIDA chamber facility of Karlsruhe Institute of Technology (KIT) in Karlsruhe and at the SAPHIR chamber of Forchungzentrum Jülich (FZJ) in Jülich. A fresh SOA was produced from ozonolysis of α-pinene or limonene and then aged by enhanced OH exposure. As an OH radical source in the AIDA-chamber the ozonolysis of tetramethylethylene (TME) was used while in the SAPHIR-chamber the OH was produced by natural light photochemistry. A general feature is that SOA produced from ozonolysis of α-pinene and limonene initially was rather volatile and becomes less volatile with time in the ozonolysis part of the experiment. Inducing OH chemistry or adding a new portion of precursors made the SOA more volatile due to addition of new semi-volatile material to the aged aerosol. The effect of OH chemistry was less pronounced in high concentration and low temperature experiments when lower relative amounts of semi-volatile material were available in the gas phase. Conclusions drawn from the changes in volatility were confirmed by comparison with the measured and modelled chemical composition of the aerosol phase. Three quantified products from the α-pinene oxidation; pinonic acid, pinic acid and methylbutanetricarboxylic acid (MBTCA) were used to probe the processes influencing aerosol volatility. A major conclusion from the work is that the OH induced ageing can be attributed to gas phase oxidation of products produced in the primary SOA formation process and that there was no indication on significant bulk or surface reactions. The presented results, thus, strongly emphasise the importance of gas phase oxidation of semi- or intermediate-volatile organic compounds (SVOC and IVOC) for atmospheric aerosol ageing.

scholarly journals Retracted: Study Hydrogeochemistry Exploration of Thermal Spring in Ramsar Area, (North of Iran)

2013 ◽  
Vol 2 (11) ◽  
pp. 134-143
Author(s):  
Hamid Reza Samadi
Keyword(s):  
Surface Temperature ◽  
Classification System ◽  
Relevant Information ◽  
Thermal Spring ◽  
Thermal Springs ◽  
High Concentration ◽  
Temperature Conductivity ◽  
Ph Values ◽  
North Of Iran ◽  
Set Up

Ramsar area is located across and between Alborze Mountain and Caspine Sea in North of Iran. About 30 spas are located south of the Ramsar and Sadatshar town. They are almost in between 20 to 70 m elevation. Paleozoic, Mesozoic and Tertiary rocks and alluvial deposit are exposed around the Ramsar area. In tertiary, acidic Plutonism was active and intrusion into the Paleozoic and Cenozoic formations. Quaternary and Alluvium deposits are exposed and extending on the Jurassic formations in Ramsar plain and have thickness lower than 10 m in show springs. The annual precipitation in the Ramsar region is 976 mm. There has not any proper Thermal spring management in Ramsar area yet. This could post some serious problem on improper management of Thermal spring sites, where its environment has been put into jeopardy. This study aims to provide a way to classify the Thermal springs in Ramsar area. The result of this study help in the classification of Thermal spring sites for official planning improvement of administration and sustainable development of natural resources of the area. The study makes use of the Department of Applied Geosciences in Islamic Azad University. GIS data of a total of 9 Thermal springs in the attempt to set up a classification system of Thermal springs in Ramsar area. These data include surface temperature, conductivity, alkalinity, acidity, TDS, pH values, H2S, Ca, Cl, Fe, K, Mg, Mn, Na, SiO2, SO4 contents, their locations, usages and other relevant information. The surface temperature of Thermal springs are between 19oC – 65oC and Na-K-Cageothermometer shows estimated reservoir temperature range from 25 o C – 195 o C. Most of the water from these Thermal springs is relatively turbidness and their composition is sodium choloride. The Thermal springs in this area generally exhibit high SiO2 and Na content; strong smell of sulfur. In addition, there are 9 Thermal springs that show high concentration of Cl, Ca, Na, K and Mg. There are three major criteria used in the classification system in this study, temperature, pH and their usage. On the basis of temperature, there are three classes of Thermal springs in Ramsar area: hyper thermal spring (10 %, 50-99o C); thermal spring (80%, 30-50o C). There is one class achieved on the basis of pH values: all of Thermal springs exhibit weak acids. There are 4 types of usage classification: swimming pools, Tourism, space heating and drying of organic materials.

Temperature and conductivity as control parameters for pollution-based real-time control

2006 ◽  
Vol 54 (11-12) ◽  
pp. 257-263 ◽  
Author(s):  
R.P.S. Schilperoort ◽  
G. Gruber ◽  
C.M.L. Flamink ◽  
F.H.L.R. Clemens ◽  
J.H.J.M. van der Graaf
Keyword(s):  
Real Time ◽  
Monitoring Network ◽  
Storm Event ◽  
Real Time Control ◽  
Normal Behaviour ◽  
Time Control ◽  
Wastewater Systems ◽  
Typical Behaviour ◽  
Good Relation ◽  
Set Up

Most sewer system performance indicators are not easily measurable online at high frequencies in wastewater systems, which hampers real-time control with those parameters. Instead of using a constituent of wastewater, an alternative could be to use characteristics of wastewater that are relatively easily measurable in sewer systems and could serve as indicator parameters for the dilution process of wastewater. This paper focuses on the possibility to use the parameters of temperature and conductivity. It shows a good relation of temperature and conductivity with the dilution of DWF (dry weather flow) during WWF (wet weather flow) a monitoring station in Graz, Austria, as an example. The simultaneous monitoring of both parameters leads to valuable back-up information in case one parameter (temperature) shows no reaction to a storm event. However, for various reasons, anomalies occur in the typical behaviour of both parameters. The frequency and extent of these anomalies will determine the usefulness of the proposed parameters in a system for pollution-based real-time control. Both the normal behaviour and the anomalies will be studied further by means of trend and correlation analyses of data to be obtained from a monitoring network for the parameters of interest that is currently being set up in the Netherlands.

Study of water salinity in the Chtouka plain (Morocco) using TEM geophysical method, chemical and isotopes tracers

2021 ◽  
Author(s):  
Henrik Schreiber ◽  
Saadou Oumarou Danni ◽  
Amine Touab ◽  
Fatima Abourig ◽  
Nelly Montcoudiol ◽  
...  
Keyword(s):  
Seawater Intrusion ◽  
Monitoring Network ◽  
Water Salinity ◽  
Geophysical Method ◽  
Transient Electromagnetic ◽  
Rock Water Interaction ◽  
Groundwater Overexploitation ◽  
Local Water ◽  
Stable Isotopes Of Water ◽  
Tem Method

&lt;p&gt;The Chtouka plain in Morocco suffers from groundwater overexploitation and a significant increase in water salinity. In this study, a multidisciplinary approach combining water chemistry, stable isotopes of water (&amp;#61540;18O, &amp;#61540;2H) and Transient Electromagnetic (TEM) method was used. The main objective was to identify the water salinity sources and the extension of the marine intrusion. Water samples were collected from wells and boreholes, springs, the Massa river and the main source of freshwater in the region, the Youssef Ibn Tachfine Dam. Geophysical (TEM) measurements (12 profiles comprising 83 measurement points) were carried out along the coastal zone and around the northern bank of the Massa river. The results show a spatial variability of water salinity, indicating rock-water interaction, seawater intrusion and anthropogenic influence. The interpretation of the TEM soundings allow to draw the front line of the marine intrusion in the aquifer. The results, compared to previous numerical simulations, show a significant progress of the marine intrusion into the coastal aquifer. The intrusion indeed reaches a distance of 2.5 km from the coast, far beyond models&amp;#8217; predictions. The local water authorities can use these results to improve their monitoring network and better assess the progress of the seawater intrusion.&lt;br&gt;Keywords: Water salinity, TEM geophysical method, chemical and isotopes tracers, marine intrusion&lt;/p&gt;

Aerobic granulation in a sequencing batch reactor (SBR) for industrial wastewater treatment

2005 ◽  
Vol 52 (10-11) ◽  
pp. 335-343 ◽  
Author(s):  
M. Inizan ◽  
A. Freval ◽  
J. Cigana ◽  
J. Meinhold
Keyword(s):  
Industrial Wastewater ◽  
Removal Rate ◽  
Batch Reactor ◽  
Experimental Tests ◽  
Cod Removal ◽  
High Concentration ◽  
Granule Formation ◽  
Aerobic Granulation ◽  
Cod Removal Rate ◽  
Set Up

Aerobic granulation seems to be an a attractive process for COD removal from industrial wastewater, characterised by a high content of soluble organic compounds. In order to evaluate the practical aspects of the process, comparative experimental tests are performed on synthetic and on industrial wastewater, originating from pharmaceutical industry. Two pilot plants are operated as sequencing batch bubble columns. Focus was put on the feasibility of the process for high COD removal and on its operational procedure. For both wastewaters, a rapid formation of aerobic granules is observed along with a high COD removal rate. Granule characteristics are quite similar with respect to the two types of wastewater. It seems that filamentous bacteria are part of the granule structure and that phosphorus precipitation can play an important role in granule formation. For both wastewaters similar removal performances for dissolved biodegradable COD are observed (&gt; 95%). However, a relatively high concentration of suspended solids in the outlet deteriorates the performance with regard to total COD removal. Biomass detachment seems to play a non-negligible role in the current set-up. After a stable operational phase the variation of the pharmaceutical wastewater caused a destabilisation and loss of the granules, despite the control for balanced nutrient supply. The first results with real industrial wastewater demonstrate the feasibility of this innovative process. However, special attention has to be paid to the critical aspects such as granule stability as well as the economic competitiveness, which both will need further investigation and evaluation.

Computational Studies for the Exhausted Flue Gas

2005 ◽  
Author(s):  
V. C. S. Ferreira ◽  
C. S. S. M. Cordeiro ◽  
J. W. Kaehler
Keyword(s):  
Flue Gas ◽  
Gas Flow ◽  
Simulation Analysis ◽  
Thermal Power ◽  
Computational Studies ◽  
Rio Grande Do Sul ◽  
High Concentration ◽  
Abrasive Particles ◽  
Set Up ◽  
Technical Solutions

Pulverized coal with low average heating, producing ashes with high percentage of silica, is fired inside the furnaces of a Thermal Power Plant (TPP) of Candiota, State of Rio Grande do Sul, Brazil. The produced hot flue gas heats the water of the ECONOMIZER 01 (ECO 01) placed inside the exhausted duct. Distorted velocity profile at inlet of ECO 01 and high concentration of abrasive particles of flue gas cause drastic erosion. So intensive has been the abrasive action that some well-identified tubes end up collapsing. The unpredictable fail has caused many non-scheduled stops of the TPP. A study focused on the reduction this effect, was set up years ago. The paper shows part of this study end present results, obtained from the numerical simulation analysis of the flue gas flow. Some technical solutions are suggested to reduce the erosion of tubes providing that avoiding it showed be impossible.

scholarly journals Green Food Development in China: Experiences and Challenges

Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 614
Author(s):  
Jiuliang Xu ◽  
Zhihua Zhang ◽  
Xian Zhang ◽  
Muhammad Ishfaq ◽  
Jiahui Zhong ◽  
...  
Keyword(s):  
Environmental Sustainability ◽  
Large Scale ◽  
Rapid Development ◽  
Arable Land ◽  
Monitoring Network ◽  
Environmental Benefits ◽  
Nutrition Security ◽  
Green Food ◽  
Set Up ◽  
Development Center

China feeds approximately 22% of the global population with only 7% of the global arable land because of its surprising success in intensive agriculture. This outstanding achievement is partially overshadowed by agriculture-related large-scale environmental pollution across the nation. To ensure nutrition security and environmental sustainability, China proposed the Green Food Strategy in the 1990s and set up a specialized management agency, the China Green Food Development Center, with a monitoring network for policy and standard creation, brand authorization, and product inspection. Following these 140 environmental and operational standards, 15,984 green food companies provided 36,345 kinds of products in 2019. The cultivation area and annual domestic sales (CNY 465.7 billion) of green food accounted for 8.2% of the total farmland area and 9.7% of the gross domestic product (GDP) from agriculture in China. Herein, we systemically reviewed the regulation, standards, and authorization system of green food and its current advances in China, and then outlined its environmental benefits, challenges, and probable strategies for future optimization and upscaling. The rapid development of the green food industry in China suggests an applicable triple-win strategy for protecting the environment, promoting agroeconomic development, and improving human nutrition and health in other developing countries or regions.

Groundwater and soil CO2 efflux weekly monitoring network for the surveillance of Cumbre Vieja volcano, Canary Islands

2020 ◽  
Author(s):  
Cecilia Amonte ◽  
Alana Mulliss ◽  
Elizabeth Sampson ◽  
Alba Martín-Lorenzo ◽  
Claudia Rodríguez-Pérez ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Monitoring Program ◽  
Monitoring Network ◽  
Volcano Monitoring ◽  
Co2 Efflux ◽  
Chemical Parameters ◽  
High Concentration ◽  
Average Value ◽  
Physical Chemical ◽  
Cumbre Vieja

&lt;p&gt;La Palma Island (708.32 km&lt;sup&gt;2&lt;/sup&gt;) is located at the north-western end of the Canary Archipelago and is one of the youngest of the archipelago. In the last 123 ka, volcanic activity has taken place exclusively at Cumbre Vieja, the most active basaltic volcano in the Canaries, which is located at the southern part of the island. Since no visible geothermal manifestations occur at the surface environment of this volcano, during the last 20 years there has been considerable interest in the study of diffuse degassing as a powerful tool in the volcano monitoring program. In this study we have used two different geochemical approaches for volcano monitoring from October 2017 to November 2019. First, we have developed a network of 21 closed static chambers to determine soil CO&lt;sub&gt;2&lt;/sub&gt; effluxes. Additionally, we have monitored physical-chemical parameters (temperature, pH, electrical conductivity -EC-) and chemical/isotopic composition and dissolved gases in the water of two galleries (Pe&amp;#241;a Horeb and Trasvase Oeste) and one water well (Las Salinas). Soil CO&lt;sub&gt;2&lt;/sub&gt; effluxes for the alkaline traps showed an average value of 7.4 g&amp;#183;m&lt;sup&gt;-2&lt;/sup&gt;&amp;#183;d&lt;sup&gt;-1&lt;/sup&gt; for the entire Cumbre Vieja volcano. The gas sampled on the head space of the traps can be considered as CO&lt;sub&gt;2&lt;/sub&gt;-enriched air, showing an average value of 1,942 ppmV of CO&lt;sub&gt;2&lt;/sub&gt;. Regarding the CO&lt;sub&gt;2&lt;/sub&gt; isotopic composition (&amp;#948;&lt;sup&gt;13&lt;/sup&gt;C-CO&lt;sub&gt;2&lt;/sub&gt;), most of the stations exhibited CO&lt;sub&gt;2&lt;/sub&gt; composed by different mixing degrees between atmospheric and biogenic CO&lt;sub&gt;2&lt;/sub&gt; with slight contributions of deep-seated CO&lt;sub&gt;2&lt;/sub&gt;, with an average value of -19.3&amp;#8240;. The results of the physical-chemical parameters measured in waters showed mean temperature values of 23.7&amp;#186;C, 19.6&amp;#186;C and 22.1&amp;#186;C, 7.40, 6.27 and 6.60 for the pH and 1,710 &amp;#181;S&amp;#183;cm&lt;sup&gt;-1&lt;/sup&gt;, 411 &amp;#181;S&amp;#183;cm&lt;sup&gt;-1&lt;/sup&gt; and 41,100 &amp;#181;S&amp;#183;cm&lt;sup&gt;-1&lt;/sup&gt; for the EC, for Pe&amp;#241;a Horeb, Trasvase Oeste and Las Salinas, respectively. The &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C-CO&lt;sub&gt;2&lt;/sub&gt; composition of the dissolved gas has a mean value of -7.8&amp;#8240;, -10.2&amp;#8240; and -3.8&amp;#8240; vs. VPDB for Pe&amp;#241;a Horeb, Trasvase Oeste and Salinas, respectively. The highest values of CO&lt;sub&gt;2&lt;/sub&gt; efflux coincided with the stations showing highest CO&lt;sub&gt;2&lt;/sub&gt; concentration values located at the southern end of Cumbre Vieja, where the most recent volcanic eruption took place, and also on the northwest flank. This is in accordance with the results obtained for Las Salinas well, located in the south of the island, which show a high concentration of dissolved CO&lt;sub&gt;2&lt;/sub&gt; and &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C-CO&lt;sub&gt;2&lt;/sub&gt; values with a strong deep-seated CO&lt;sub&gt;2&lt;/sub&gt; contribution. This study represents an interesting contribution to detect early warning signals of future unrest episodes at Cumbre Vieja.&lt;/p&gt;

scholarly journals Two instruments based on differential optical absorption spectroscopy (DOAS) to measure accurate ammonia concentrations in the atmosphere

2011 ◽  
Vol 4 (4) ◽  
pp. 5037-5078
Author(s):  
H. Volten ◽  
J. B. Bergwerff ◽  
M. Haaima ◽  
D. E. Lolkema ◽  
A. J. C. Berkhout ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Absorption Spectroscopy ◽  
Monitoring Network ◽  
Fast Response ◽  
High Accuracy ◽  
Differential Optical Absorption Spectroscopy ◽  
Optical Absorption Spectroscopy ◽  
Open Path ◽  
Set Up ◽  
Similar Accuracy

Abstract. We present two Differential Optical Absorption Spectroscopy (DOAS) instruments built at RIVM, the RIVM DOAS and the miniDOAS. Both instruments provide virtually interference free measurements of NH3 concentrations in the atmosphere, since they measure over an open path, without suffering from inlet problems or interference problems by ammonium aerosols dissociating on tubes or filters. They measure concentrations up to at least 200 μg m−3, have a fast response, low maintenance demands, and a high up-time. The RIVM DOAS has a high accuracy of typically 0.15 μg m−3 for ammonia over 5-min averages and over a total light path of 100 m. The miniDOAS has been developed for application in measurement networks such as the Dutch National Air Quality Monitoring Network (LML). Compared to the RIVM DOAS it has a similar accuracy, but is significantly reduced in size, costs, and handling complexity. The RIVM DOAS and miniDOAS results showed excellent agreement (R2 = 0.996) during a field measurement campaign in Vredepeel, the Netherlands. This measurement site is located in an agricultural area and is characterized by highly variable, but on average high ammonia concentrations in the air. The RIVM-DOAS and miniDOAS results were compared to the results of the AMOR instrument, a continuous-flow wet denuder system, which is currently used in the LML. Averaged over longer time spans of typically a day the (mini)DOAS and AMOR results agree reasonably well, although an offset of the AMOR values compared to the (mini)DOAS results exists. On short time scales the (mini)DOAS shows a faster response and does not show the memory effects due to inlet tubing and transport of absorption fluids encountered by the AMOR. Due to its high accuracy, high uptime, low maintenance and its open path, the (mini)DOAS shows a good potential for flux measurements by using two (or more) systems in a gradient set-up and applying the aerodynamic gradient technique.

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