How much you are familiar with Environmental water quality Models

 چقدر با مدلهای کیفیت آب آشنایی دارید؟

چرا باید مسائل زیست محیطی رودخانه ها و سد ها را بیشتر در نظر بگیریم؟
چگونه میتوان با شیمی محیط زیست خطرات را ارزیابی کرد؟
مدلهای ریاضی مناسب کیفی آب در رودخانه ها , کدامند؟

مدلهای ....WASP7, QUAL12, SWAT, SMADA, MAIKE....
...چه کمکی به ما میکنند؟

How models like WASP7, QUAL12,
SWAT, SMADA, MAIKE help to us
با چه روشهای ساده ای کیفیت آب قبل از رسیدن به تصفیه خانه (در رودخانه و سدها ) تغییر میکند ؟
 !

 

please waite a minute  

 

 شما را نمیدانم , ولی من میخواهم بدانم ,اگر چیزی در اختیار دارید که در این راه به من کمک میکند.
لطفا دریغ نکنید .

 شما در مورد ارزیابیهای خطر تقریبا همه جا شنیده اید, اما آیا بروشنی فهمیده اید آنکه  چیست؟  ابزار و اثرات آن چگونه است؟

now more wait and see deep, why are them

see small peaces and big things ,look at the pictures  carefully , all are talking to you

 

 please set your idea and messages in this section

Water analysis accuracy tester

TDS and Electrical Conductivity

Water hardness calculator

 more sites about accuracy tester

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Dissolved oxygen saturation tables

========================

Download the Alkalinity Calculator

EPA On-line Tools for Site Assessment Calculation

http://www.epa.gov/ATHENS/learn2model/part-two/onsite/toc_onsite.htm

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SOLUTIONS

PERCENT, MOLAR, NORMAL, SATURATED

Solutions Menu

Percent

Molar

Normal

Solutions from Solutions and Titrations

Concentrated Solutions (making solutions from concentrated solutions)

===============

Calculating NSF Water Quality Index

Water Quality Index: pH

Water Quality Index: Turbidity

Water Quality Index: BOD

Water Quality Index: Nitrate

Water Quality Index: Total Phosphate

Alkalinity Speciation Calculator

More References Related to :

WQI Index- Consumer Support Group Online Calculators
http://www.csgnetwork.com/h2oqualindexcvttemponlycalc.html

Path Finder Science
http://pathfinderscience.net/stream/cproto4.cfm

Water Quality Index Stream Monitoring Program
http://www.ecy.wa.gov/pubs/0203052.pdf

Water Quality Index System for Rivers in Malaysia
http://agrolink.moa.my/did/river/sgklang/sgklang_wqi.htm

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 A. Schezerianum

============

Analysis methods environmental chemistry

The best way to determinat water quality is SMWW or 

Standard Methods for Examination of Water & Wastewater (Standard Methods for the Examination of Water and Wastewater)
by Lenore S. Clescerl, Arnold E. Greenberg, Andrew D. Eaton

or

free

http://rapidshare.com/files/65046390/SMWW-StandardMethodsForTheExaminationOfWater_Wastewater-APHA_AWWA_20thEd-1999

http://rapidshare.com/files/89117694/smww_20th_pdf.rar

=====================

If you know any better Analytical method please inform me by sending your massage

  پیام های شما برای من(.....)  set your message to me please  ( ......  ) 

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Water Quality Parameters and Methods used for Analysis

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 Quality control measures

Quality control measures were started from the filed. Standard sampling methods were adopted to collect the samples. Four types of samples were collected for monitoring purpose where as three kinds of samples were collected for quality control. The detail of these samples is as under:

     Maximum Holding time (MHTs) for common water quality determain parameters 

Samples for Monitoring Purposes

a)  Samples for microbiological examination in sterile bottle.

b) Samples for the analysis of trace elements by addition of HNO₃ as preservative.

c) Samples for the analysis of Nitrate (N) by addition of boric acid as preservative.

d) Samples without preservative for the analysis of EC, pH, Hardness, Ca,      Mg, Na, K and HCO₃ etc.

============

==============

 Why Should You Measure the TDS level in your Water?
  The EPA Secondary Regulations advise a maximum contamination level (MCL) of 500mg/liter (500 parts per million (ppm)) for TDS. Numerous water supplies exceed this level. When TDS levels exceed 1000mg/L it is generally considered unfit for human consumption. A high level of TDS is an indicator of potential concerns, and warrants further investigation. Most often, high levels of TDS are caused by the presence of potassium, chlorides and sodium. These ions have little or no short-term effects, but toxic ions (lead arsenic, cadmium, nitrate and others) may also be dissolved in the water.

============================

How to Measure Dissolved Oxygen

Sampling stations and depths should be selected according to whether or not you are trying to measure these differences or notWhen collecting stream DO samples at several stations for comparison, it is important to select stations with similar flow conditions.

------------------======Azide-winkler method - ===----------------

Measuring pH Accurately

======

  A CONVENTIONAL METHOD FOR MEASURING
THE pH OF A SOLUTION

·  Allow the meter to warm up.

·  Open the filling hole; be certain filling solution is nearly to the top. (Refillable electrodes only.)

·  If the meter has a "standby” mode, use it when the electrodes are not immersed. Use the "pH" mode to read the pH of a sample or standard.

·  Calibrate the system each day or before use:

Adjust the meter temperature setting to room temperature, or use an ATC probe.

Obtain two standard buffers: pH of 7.00 at room temperature and an acidic standard if the sample is acidic and a basic standard if the sample is basic.

Rinse the electrodes with distilled water and blot dry. Do not wipe the electrodes as this may create a static charge leading to an erroneous reading.

Immerse the electrodes pH 7.00 calibration buffer. Be certain that the junction is immersed and that the level of sample is below the level of the filling solution. Disengage the standby mode (if present) or follow the manufacturer’s instructions. Allow the reading to stabilize.

Adjust the meter to read 7.00. Go to the standby mode (if present).

Remove the electrodes, rinse with distilled water, and blot dry. Alternatively, rinse the electrodes with the next solution and do not dry.

Place the electrodes in the second standardization buffer, set the meter to read pH, and allow the reading to stabilize. Adjust the meter to the pH of the second buffer with the proper method of adjustment. Remove, rinse, and blot the electrodes.

With an older pH meter, recheck the pH 7.00 buffer as in step d and readjust as necessary. Recheck the second buffer and readjust the meter as necessary. Readjust as needed up to three times. If the readings are not within 0.05 pH units of what they should be after three adjustments, the electrode probably needs cleaning

Optional: It is possible to perform quality control checks at this point.

a.                   Linearity Check. To check the linearity of the measuring system, take the reading of a third calibration buffer. For example, if the meter was calibrated with pH 7.00 and pH 10.00 buffers, check a pH 4.00 calibration buffer. Immerse the electrodes in the third buffer, allow the reading to stabilize, and record the value. Do not adjust the meter to this third calibration buffer; the purpose of this third buffer is to check the system’s linearity. If the reading is not within the proper range, as defined by the laboratory’s quality control procedures, the electrodes require maintenance.

b.                  A second quality control check is to test the pH of a control buffer whose pH is known and that has a pH close to the pH of the sample. It is common to set the maximum allowable error of the control buffer to be ± 0.10 pH units. Do not adjust the meter to the pH of the control buffer; the purpose of this buffer is to check the accuracy of the system. If the pH reading of the control buffer is not within the required tolerance, the electrodes require maintenance.

=======

Image:Glass-microreactor

.

Lab-on-a-chip made of glass, developed at Micronit Microfluidics

Lab-on-a-chip (LOC) is a term for devices that integrate (multiple) laboratory functions on a single chip of only millimeters to a few square centimeters in size and that are capable of handling extremely small fluid volumes down to less than pico liters. Lab-on-a-chip devices are a subset of MEMS devices and often indicated by "Micro Total Analysis Systems" (µTAS) as well. Microfluidics is a broader term that describes also mechanical flow control devices like pumps and valves or sensors like flowmeters and viscometers. However, strictly regarded "Lab-on-a-Chip" indicates generally the scaling of single or multiple lab processes down to chip-format, whereas "µTAS" is dedicated to the integration of the total sequence of lab processes to perform chemical analysis. The term "Lab-on-a-Chip" was introduced later on when it turned out that µTAS technologies were more widely applicable than only for analysis purposes

Industrial and academic sectors, including: all areas of chemistry; pharmaceuticals; medicine; analytical science; synthesis; biotechnology; BioMEMS; physics; material science; bioengineering and electronics

Incorporation of well controlled temperature gradients into a microreactor provides a powerful route to separate the nucleation and growth during the synthesis of quantum dots, resulting in good size uniformity of the formed products.

.

application areas

Microfluidic structures include on one hand micropneumatic systems, i.e. microsystems for the handling of off-chip fluids (liquid pumps, gas valves, etc), and on the other hands microfluidic structures for the on-chip handling of nano- and picolitre volumes. The commercially most successful application today is the inkjet printhead.Advances in microfluidics technology are revolutionizing molecular biology procedures for enzymatic analysis (e.g., glucose and lactate assays), DNA analysis (e.g., polymerase chain reaction and high-throughput sequencing), and proteomics. The basic idea of microfluidic biochips is to integrate assay operations such as detection, as well as sample pre-treatment and sample preparation on one chip. An emerging application area for biochips is clinical pathology, especially the immediate point-of-care diagnosis of diseases. In addition, microfluidics-based devices, capable of continuous sampling and real-time testing of air/water samples for biochemical toxins and other dangerous pathogens, can serve as an always-on "bio-smoke alarm" for early warning.

Silicone rubber and glass microfluidic devices. Top: a photograph of the devices. Bottom: DIC micrographs of an undulating channel ~15 μm wide.

Glass-coated microchannels

28 February 2008

Scientists in the US have developed a simple method of coating the channels of microfluidic devices to make them more resistant to chemicals.

David Weitz and colleagues from Harvard University, Cambridge, used a sol-gel method to create a glass coating on polydimethylsiloxane (PDMS) microchannels. PDMS, a type of silicone rubber, is easy to make into microfluidic devices using soft lithography, where the material is 'stamped' with a channel pattern. This makes it ideal for large-scale use.

However, PDMS is not a robust material. It is permeable to liquids and gases, which can affect reactions occurring in the channels. Additionally, organic solvents make the PDMS channels swell, degrading device performance. Glass, on the other hand, is a far more chemically robust material but is much more difficult to make into microfluidic devices.

The glass coating developed by Weitz's group is easily deposited on PDMS channels and acts as a barrier, providing resistance to chemicals and solvents. Weitz said that this method of coating would make device production easier as it 'combines the chemical robustness of glass with the ease of fabrication of PDMS'.

The scientists discovered that the coated channels were resistant to the fluorescent chemical Rhodamine B. After an hour of exposure to the organic solvent toluene the channels changed very little. By contrast, uncoated channels swelled upon exposure to toluene.

Stephen Haswell, who develops microfluidic devices at the University of Hull, UK, said that although there would be issues with performing reactions at high temperatures, the work represented a step towards merging the advantages of PDMS and glass. 'Lack of chemical resistance is a big problem, and it will be something of a breakthrough to extend the fabrication benefits of PDMS to give more glass-type robustness,' he said.

Weitz's group are working on refining the technique so that the thickness of the coating can be more finely controlled. 'We are also developing extensions to the method which take advantage of the glass coating,' he said.

Fay Riordan

Link to journal article

Glass coating for PDMS microfluidic channels by sol–gel methods
Adam R. Abate, Daeyeon Lee, Thao Do, Christian Holtze and David A. Weitz, Lab Chip, 2008
DOI: 10.1039/b800001h

Also of interest

Rapid reactions using microfluidic devices

A glass microchip has been used for the first time to carry out fast carbonylative cross-coupling reactions of arylhalides to form secondary amides.

Microfluidic devices with heart

Japanese researchers have harnessed the pumping power of heart cells to make better microfluidic devices.

 where is the shop of this kind of glass,?do you know

---------------------===----------------------

familiar instrumental 

 ICP)(1)

Inductively coupled plasma

 Inductively coupled plasma atomic emission spectroscopy (ICP-AES), also referred to as Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), is a type of emission spectroscopy that uses a plasma (e.g. inductively coupled plasma) to produce excited atoms and ions that emit electromagnetic radiation at a wavelength characteristic of a particular element.^[1][2] The intensity of this emission is indicative of the concentration of the element within the sample.

Applications

Examples of the application of ICP-AES include the determination of metals in wine,^[3] arsenic in food,^[4] and trace elements bound to proteins.^[5

 

ICP-MS Instrument
Acronym	ICP-MS
Classification	Mass spectrometry
Analytes	Inorganic compounds Organometallics

 

 

 

Radioactive pollution can be defined as the release of radioactive substances or high-energy particles into the air, water, or earth as a result of human activity, either by accident or by design. The sources of such waste include: 1) nuclear weapon testing or detonation; 2) the nuclear fuel cycle, including the mining, separation, and production of nuclear materials for use in nuclear power plants or nuclear bombs; 3) accidental release of radioactive material from nuclear power plants. Sometimes natural sources of radioactivity, such as radon gas emitted from beneath the ground, are considered pollutants when they become a threat to human health.

Since even a small amount of radiation exposure can have serious (and cumulative) biological consequences, and since many radioactive wastes remain toxic for centuries, radioactive pollution is a serious environmental concern even though natural sources of radioactivity far exceed artificial ones at present.

====================================================== 

Iranian Scientist  in radio polutions 

====================================================

I am so busy so i have littel time to think about my probelems and involved it 

===================================================

3112 B. Cold-Vapor Atomic Absorption Spectrometric Method
1. General Discussion This method is applicable to the determination of mercury.
2. Apparatus hen possible, dedicate glassware for use in Hg analysis. Avoid using glassware previously xposed to high levels of Hg, such as those used in COD, TKN, or Cl– analysis. . Atomic absorption spectrometer and associated equipment: See Section 3111A.6. nstruments and accessories specifically designed for measurement of mercury by the cold vapor technique are available commercially and may be substituted.  b. Absorption cell, a glass or plastic tube approximately 2.5 cm in diameter. An 11.4-cm-long ube has been found satisfactory but a 15-cm-long tube is preferred. Grind tube ends erpendicular to the longitudinal axis and cement quartz windows in place. Attach gas inlet andoutlet ports (6.4 mm diam) 1.3 cm from each end. . Cell support: Strap cell to the flat nitrous-oxide burner head or other suitable support and lign in light beam to give maximum transmittance.
d. Air pumps: Use any peristaltic pump with electronic speed control capable of delivering 2  air/min. Any other regulated compressed air system or air cylinder also is satisfactory. . Flowmeter, capable of measuring an air flow of 2 L/min.
f. Aeration tubing, a straight glass frit having a coarse porosity for use in reaction flask. g. Reaction flask, 250-mL erlenmeyer flask or a BOD bottle, fitted with a rubber stopper to hold aeration tube. . Drying tube, 150-mm × 18-mm-diam, containing 20 g Mg (ClO4)2. A 60-W light bulb ith a suitable shade may be substituted to prevent condensation of moisture inside the bsorption cell. Position bulb to maintain cell temperature at 10°C above ambient. . Connecting tubing, glass tubing to pass mercury vapor from reaction flask to absorption ell and to interconnect all other components. Clear vinyl plastic*#(79) tubing may be ubstituted for glass.
3. Reagents†#(80) . Metal-free water: See Section 3111B.3c.
b. Stock mercury solution: Dissolve 0.1354 g mercuric chloride, HgCl2, in about 70 mL water, add 1 mL conc HNO3, and dilute to 100 mL with water; 1.00 mL = 1.00 mg Hg. . Standard mercury solutions: Prepare a series of standard mercury solutions containing 0 to  μg/L by appropriate dilution of stock mercury solution with water containing 10 mL concHNO3/L. Prepare standards daily. . Nitric acid, HNO3, conc.
e. Potassium permanganate solution: Dissolve 50 g KMnO4 in water and dilute to 1 L. f. Potassium persulfate solution: Dissolve 50 g K2S2O8 in water and dilute to 1 L.
g. Sodium chloride-hydroxylamine sulfate solution: Dissolve 120 g NaCl and 120 g
(NH2OH)2⋅H2SO4 in water and dilute to 1 L. A 10% hydroxylamine hydrochloride solution may e substituted for the hydroxylamine sulfate. . Stannous ion (Sn2+) solution: Use either stannous chloride, ¶ 1), or stannous sulfate, ¶ 2), o prepare this solution containing about 7.0 g Sn2+/100 mL. 1) Dissolve 10 g SnCl2 in water containing 20 mL conc HCl and dilute to 100 mL.
2) Dissolve 11 g SnSO4 in water containing 7 mL conc H2SO4 and dilute to 100 mL.
Both solutions decompose with aging. If a suspension forms, stir reagent continuously during use. Reagent volume is sufficient to process about 20 samples; adjust volumes prepared toaccommodate number of samples processed.
i. Sulfuric acid, H2SO4, conc. . Procedure . Instrument operation: See Section 3111B.4b. Set wavelength to 253.7 nm. Install bsorption cell and align in light path to give maximum transmission. Connect associated quipment to absorption cell with glass or vinyl plastic tubing as indicated in Figure 3112:1. urn on air and adjust flow rate to 2 L/min. Allow air to flow continuously. Alternatively, follow anufacturer’s directions for operation. NOTE: Fluorescent lighting may increase baseline noise.
b. Standardization: Transfer 100 mL of each of the 1.0, 2.0, and 5.0 μg/L Hg standard solutions and a blank of 100 mL water to 250-mL erlenmeyer reaction flasks. Add 5 mL conc 2SO4 and 2.5 mL conc HNO3 to each flask. Add 15 mL KMnO4 solution to each flask and let tand at least 15 min. Add 8 mL K2S2O8 solution to each flask and heat for 2 h in a water bath at 5°C. Cool to room temperature. Treating each flask individually, add enough NaCl-hydroxylamine solution to reduce excess MnO4, then add 5 mL SnCl2 or SnSO4 solution and immediately attach flask to aeration apparatus. As Hg is volatilized and carried into the absorption cell, absorbance will increase to a aximum within a few seconds. As soon as recorder returns approximately to the base line, emove stopper holding the frit from reaction flask, and replace with a flask containing water. lush system for a few seconds and run the next standard in the same manner. Construct a
standard curve by plotting peak height versus micrograms Hg.
c. Analysis of samples: Transfer 100 mL sample or portion diluted to 100 mL containing not more than 5.0 μg Hg/L to a reaction flask. Treat as in ¶ 4b. Seawaters, brines, and effluents highin chlorides require as much as an additional 25 mL KMnO4 solution. During oxidation step, hlorides are converted to free chlorine, which absorbs at 253 nm. Remove all free chlorine efore the Hg is reduced and swept into the cell by using an excess (25 mL) of hydroxylamine eagent.
Remove free chlorine by sparging sample gently with air or nitrogen after adding
hydroxylamine reducing solution. Use a separate tube and frit to avoid carryover of residual stannous chloride, which could cause reduction and loss of mercury.
5. Calculation etermine peak height of sample from recorder chart and read mercury value from standard urve prepared according to ¶ 4b.
6. Precision and Bias ata on interlaboratory precision and bias for this method are given in Table 3112:I

1. Refference : KOPP, J.F., M.C. LONGBOTTOM & L.B. LOBRING. 1972. ‘‘Cold vapor’’ method for
determining mercury. J. Amer. Water Works Assoc. 64:20..

Compendium of Pesticide Common Names

Classified Lists of Pesticides

These classified lists of pesticides include all of the compounds in the Compendium of Pesticide Common Names, of which there are more than 1500.

Each major group of pesticides (e.g. herbicides or plant growth regulators) is subdivided into chemical or other classes (e.g. chloroacetanilide herbicides or auxins).

Pesticide or herbicide polymer complexes for forming aqueous dispersions

 This is a invention and it  relates to pesticides and herbicides which form complexes with a polymer for storage and handling as a solid, the pesticides and herbicides instantly dispersable into a stable emulsion when added to water.

they will develope there resistance

to insecticides 

Environmental Impact Statement

Document Title

would you like go to this site 

FEASIBILITY STUDY DOCUMENTATION

Conversion Factors @ ChemScience

1 megagram (Mg) = 1 000 kilograms

1 kilogram (kg) = 1 000 grams (g)

1 gram (g) = 1 000 milligrams (mg)

1 milligram (mg) = 1 000 micrograms (γg)

1 microgram (γg) = 1 000 nanograms (ng)

1 nanogram (ng) = 1 000 picograms (pg)

EXAMPLE of different concentration units:

5.84% m/v sodium chloride solution = 5.84g sodium chloride (solute) dissolved in water (solvent) made up to final volume of 100ml (solution);

 = 58 400ppm NaCl = 58 400mg NaCl/litre = 1.0 mol/l = 1.0N NaCl = 1.0M NaCl

 = 1.0 mol NaCl dm^-3

where:

N   = Normal Solution = number of gram-equivalent mass of solute per one litre solution;

M   = Molarity Solution = number of moles of solute per one litre solution = mol dm^-3 = mol l^-1;

m   = Molality Solution = number moles of solute per one kilogram solvent = mol kg^-1;

F    = Formality Solution = number gram-formula mass solute per one litre solution;

mol = mole = gram-molecular weight of substance = amount of substance (solute).

Temperature conversion factors:

· degrees Fahrenheit (°F) to Centigrade:   °C = (5 (°F - 32)) /9

· degrees Centigrade (°C) to Fahrenheit:   °F = (9/5 °C) + 32                                                                        

· degrees Kelvin (°K) to Centigrade:        °C = °K - 273.15

· degrees Fahrenheit (°F) to Rankine:       °R = °F + 459.67

· degrees Réaumur (°r) to Centigrade:      °C = (°r-10)/8

NOTE:   degrees Centigrade = degrees Celsius

               degrees Kelvin = degrees International Temperature ical (1968)

· parts per million = ppm = 1 part solute in 1 000 000 parts solution:

ppm by volume = g/m³ = mg/l  = mg/dm³ = ug/ml = ng/ul = % m/v x 10⁴ 

ppm by weight = g/mg = mg/kg = ug/g = ng/mg = % m/m x 10⁴

  · parts per billion (US) = ppb = 1 part solute in 1 000 000 000 parts solution:

ppb by volume = ug/l = ng/ml = pg/ul = % m/v x 10⁷ 

ppb by weight = ug/kg = ng/g = pg/mg = % m/m x 10⁷

· parts per billion (UK) = ppb = 1 part solute in 1 000 000 000 000 parts solution

· % m/m = percentage mass by mass = g/100g;

    % v/v = percentage volume by volume = ml/100ml;

· ppm by weight = ppm by volume x density

· 1 g/ml = 1kg/l = 1 x 10³ kg/m³ = 1 x 10² kg/hectoliter

· 1 g/l = 1 kg/m³

Some useful technical information and unit conversion factors

Prefixes:

tera                     T           10¹²

giga                    G           10⁹

mega                  M           10⁶

kilo                     k            10³

hector\                h            10²

deca                   da          10

deci                    d            10^-1       

centi                   c            10^-2

milli                     m           10^-3

micro                  γ            10^-6

nano                   n            10^-9

pico                    p            10^-12

femto                  f            10^-15

atto                     a            10^-18

Some typical chemical reactions and examples:

FORMATION: elements to compounds, e.g. C + O₂ = CO₂ (combustion)

COMBINATION: two or more substances to form a new substance, e.g. 2Na + Cl₂ = 2NaCl

OXIDATION-REDUCTION: oxidation states change, e.g. xFe + 3O₂ = xFe₂O₃ (rusting)

NEUTRALISATION: acid/alkali, e.g. HCl + NaOH = NaCl + H₂O (forms a salt)

DECOMPOSITION: single substance yields multiple substances, e.g. 2HgO = 2Hg + O₂

DISPLACEMENT: element replaces another element to form a compound, e.g. Zn + 2HCl = H₂ + ZnCl

Some other useful and interesting chemical websites:

www.saci.co.za                                                      The South African Chemical Institute, membership, seminars

www.rsc.org                                                           The Royal Society of  Chemistry, membership, news, etc

www.chemsoc.org                                                 The Chemical Society, news, articles, etc

www.chemicalonline.com                                      News & info on industry

www.sanas.co.za                                                  The South African National Accreditation System

www.nla.org.za                                                       National Laboratory Association, training, seminars, etc

www.iupac.org                                                        International Union of Pure & Applied Chemistry

www.chemfinder.com                                            Chemical structures

http://casweb.cas.org/chempatplus/                      Chemical patents

www.xe.net/currency/                                            Currency converter

www.tucows.co.za                                                 Internet programmes

www.geocities.com                                                Personal WebPages

www.google.com                                                   Best search engine

www.allexperts.com                                               For expert advice

http://uncweb.carl.org                                            Uncover document awareness service

www.onelook.com                                                 Reference materials

www.eevl.ac.uk/eese/                                            Engineering search engine

www.albany.edu/library/internet/syntax.html         Reference to search engine syntax

www.chemicalbid.com                                           Chemical auctions

www.freemarkets.com                                           Auction site

www.techex.com                                                   Technology exchange

www.chemcenter.org                                             American Chemical Society

http://chemweb.com                                               Chemistry general, forums, etc

www.chem.ucla.edu/chempointers.html                Chemistry library

www.cas.org                                                          Chemistry abstracts (CAS)

www.beilstein.com                                                 Organic chemistry

http://chemfinder.camsoft.com                               Links to chemical databases

http://physchem.ox.ac.uk/MSDS/                          Material safety data sheets

www.shef.ac.uk/~chem/web-elements                  Info on chemical elements

WEIGHT:

kilograms x 2.2046 = lbs  (pounds)

lbs x 0.4536 = kilograms

grams x 0.0352740 = ounces (US)

grams x  0.0321507 = ounces (troy)

VOLUME:

litres x 0.2642 = gallons (US)

litres x 0.21997 = gallons (Imperial)

litre x 0.56825 = pints    or

1 litre = 1.7598 pints

8 pints = 1 gallon (Imperial) = 4.546 litres

1 litre = 1000.027 cc = 35.1960 fluid ounces

1. alt.                  alternative
2. approx.            approximately
3. a.s.a.p.            as soon as possible
4. C                     century
5. c.                     approximately
6. cd                    could
7. cf.                    compare
8. cont’d               continued
9. exc.                  except
10. e.g.                  for example
11. esp.                 especially
12. et al.                and others
13. et seq.              and what follows
14. ff.                              following pages
15. fr.                              from
16. ibid.                 in the same work as quoted above
17. inc.                  including
18. i.e.                   that is
19. info                  information
20. i.r.o.                in respect of
21. no.                   number
22. op. cit.             in the work quoted
23. opp.                 opposite
24. p.                     page
25. pp.                   pages
26. q.v.                  see
27. re:                   with reference to
28. shd                  should
29. usu.                 usually
30. v.                     very
31. vs                              against
32. viz.                  namely
33. wd                   would
34. wh.                  which
35. w/o                  without

1. +                      and
2. &                     and
3. =                      equals
4. ¹                      doesn’t equal
5. <                      less than
6. >                      more than
7. //                    parallel, similar or equivalent to
8. \                     therefore
9. Q                     because
10. @                     approximately equal to
11. ®                      it follows that
12. ¬                       results from, depends upon
13. #                      space

           

 

 

 

2. The Bangladesh arsenic crisis

Arsenic is a poisonous metalloid that can be found in three forms; yellow, grey and black arsenic. Arsenic compounds are used as pesticides and in various alloys. It is not only toxic to insects and some plants, but also to humans. Its toxicity stems from the similarity of the chemical structure to phosphorus, causing it to partly substitute phosphorus in chemical reactions.
Bangladesh, has had major drinking water problems for many decades. Most people used to drink surface water, which led to the spread of pathogens such as cholera and dysentery. International organizations started promoting groundwater welling for drinking water production. It was however not known that groundwater in Bangladesh contained significant amounts of arsenic. The arsenic present in the groundwater is of natural origin, being released from subsurface sediment layers under anoxic conditions. Many other Asian countries, such as Vietnam, Cambodia and Tibet are thought to have similar geological environments as Bangladesh. These countries may also have high-arsenic groundwater.

When drinking water wells were installed in Bangladesh, approximately 57 million Bangladeshi people started drinking groundwater with arsenic concentrations far above the legal limit of 0,05 mg/L. After several years of applying groundwater as drinking water over a quarter of the Bangladeshi population exhibited symptoms of arsenic poisoning (arsenicosis).
Arsenic poisoning kills people by disrupting the digestive system. Symptoms include changes in skin colour, formation of skin patches (see picture), stomach pains, vomiting, delirium and gangrene. Chronic low level arsenic poisoning in Bangladesh also results in cancers, such as lung cancer, skin cancer, kidney cancer and bladder cancer.

The arsenic problem was first discovered in the early 1980s, but public awareness of the arsenic crisis did not emerge until the mid-1990s. The World Health Organisation has described the naturally occurring arsenic as the largest mass poisoning of a population in history. Today, more than 85 million Bangladeshi people are drinking the arsenic-rich groundwater. It is very probable at least 80 million people now suffer from arsenic poisoning. The exact number is uncertain because it may sometimes take up to 10 years before arsenic poisoning can be diagnosed.

Legal proceedings began in London in 2003 to determine whether the British Geological Survey was negligent in failing to detect arsenic in Bangladeshi water supplies. The organization conducted research on behalf of the Bangladesh government in 1992, but did not test the groundwater for arsenic. The organization pleas 'not guilty' and argues that at the time of its report little was known about the geological origins of arsenic poisoning.

 .

 Determination of arsenic with sodium borohydride

 hydride generator: The basic unit is composed of two parts: a precision
peristaltic pump, which is used to meter and mix reagents and sample solutions, and the
gas-liquid separator. At the gas-liquid separator a constant flow of argon strips out the hydrogen and metal hydride gases formed in the reaction and carries them to the heated quartz absorption cell (Section 3114B.1b and Section 3114B.2b), which is supported by a metal bracket mounted on top of the regular air acetylene burner head. The spent liquid flows out of the separator via a 

constant level side drain to a waste bucket. Schematics and operating parameters are shown in.

Check flow rates frequently to ensure a steady flow; an uneven flow in any tubing will cause
an erratic signal. Remove tubings from pump rollers when not in use. Typical flow rates are: sample, 7 mL/min; acid, 1 mL/min; borohydride reagent, 1 mL/min. Argon flow usually is re-fixed, typically at 90 mL/min.
 
 .Determination of arsenic with sodium borohydride: To 50 mL digested standard or sample in a 200-mL Berzelius beaker (see Figure 3114:1) add 5 mL conc HCl and mix. Add 5 mL NaI rereductant solution, mix, and wait at least 30 min. (NOTE: The NaI reagent has not been found necessary for certain hydride reaction cell designs if a 20 to 30% loss in instrument sensitivity is not important and variables of solution acid conditions, temperatures, and volumes for production of As(V) and arsine can be  controlled strictly. Such control requires an automated delivery system ;
 .Attach one Berzelius beaker at a time to the rubber stopper containing the gas dispersion tube for the purging gas, the sodium borohydride reagent inlet, and the outlet to the quartz cell.
Turn on strip-chart recorder and wait until the base line is established by the purging gas and all air is expelled from the reaction cell. Add 0.5 mL sodium borohydride reagent. After the nstrument absorbance has reached a maximum and returned to the base line, remove beaker,inse dispersion tube with water, and proceed to the next sample or standard. Periodically ompare standard As(III) and As(V) curves for response consistency. Check for presence of hemical interferences that suppress instrument response for arsine by treating a digested sample ith 10 μg/L As(III) or As(V) as appropriate. Average recoveries should be not less than 90%.
 Calculation

Construct a standard curve by plotting peak heights or areas of standards versus
concentration of standards. Measure peak heights or areas of samples and read concentrations from curve. If sample was diluted (or concentrated) before sample digestion, apply an ppropriate factor. On instruments so equipped, read concentrations directly after standard alibration.
 .

Arsenic Poisoning

It is another  usfull weblog

 please set your idea and messages in this section

 =============================================================================

who is rigth? the one is killed or killer?i

  you know that some one that dont shake hand  others , but he alwase shake hand (touched)  animals (who is right?)i

------------------------======-----------------------

and now this is some thing in my heart

 .....

 تو، هشتمین خورشیدی که درسایه‌اش آسمان را تجربه کرده‌ایم

..... in mashhad,Iran It is a picture of emam reza mausoleum ..

مشهد مقدس -- حرم آقا علی ابن موسی الرضا (ع)

روضه منوره (ضریح مطهر )

پخش زنده ومستقیم از کربلا و مشهد و نجف

An atheist professor of philosophy speaks to his class on the problem science has with God, The Almighty. He asks one of his new students to stand and.....

Prof: So you believe in God?

Student: Absolutely, sir.

Prof: Is God good?

Student: Sure.

Prof: Is God all-powerful?

Student: Yes.

Prof: My brother died of cancer even though he prayed to God to heal him. Most of us would attempt to help others who are ill. But God didn't. How is this God good then? Hmm?
(Student is silent.)

Prof: You can't answer, can you? Let's start again, young fella. Is God good?

Student: Yes.

Prof: Is Satan good?

Student: No.

(The class is in uproar.)

Student: Is there anyone in the class who has ever seen the Professor's brain?
(The class breaks out into laughter.)

Student: Is there anyone here who has ever heard the Professor's brain, felt it, touched or smelt it? No one appears to have done so. So, according to the established rules of empirical, stable, demonstrable protocol, science says that you have no brain,sir. With all due respect, sir, how do we then trust your lectures, sir?
(The room is silent. The professor stares at the student, his face unfathomable.)

Prof: I guess you'll have to take them on faith, son.


Student: That is it sir... The link between man & god is FAITH . That is all that keeps things moving & alive.

NB: I believe you have enjoyed the conversation...and if so...you'll probably want your friends/colleagues to enjoy the same...won't you?....this is a true story, and the student was none other than......... 

Dr APJ Abdul Kalam, the former President of India .

When I was a child I saw in my dream  that Some one was fasten me with chain to others

I thought he was mohamad massenger of moseams

than I saw more and more thing that make my life nice more and more

I hope to accure for others too

so

It is naturaly I think about environmental intellectuality of the world

Is it means like this picture? so

please send your massage

Macca

Time Series Modelling of Water Resources and Environmental Systems

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SAMPLING AND ANALYSIS OF ENVIRONMENTAL CHEMICAL POLLUTION

ACOMPLEATE GUIDE

EMMA P. POPEK

Data Plotting

The Durov diagram can be used to plot all samples in the open database or selected sample groups. In addition, the symbols representing the sample values can be customized according to shape and color. Other options include individual multiplication factors for each selected ion to prevent data point accumulation along a base line. The highlighted sample points indicate samples that are selected in the database and are also highlighted on all other open graphical displays.

Environmental changes may be traced far downstream, at times even out into the sea. In the tropics there may be great seasonal variations as to the amount of precipitation, and in dry periods evaporation from lakes and reservoirs may be considerable. This may affect the water level of the reservoirs more dramatically than in temperate areas. The watercourse and its watershed mutually influence each other. The watercourse, for example, may affect the local climate and the ground-water level in surrounding areas. The sedimentation taking place in a reservoir can often lead to an increased erosion downstream, i.e. an increase in the total erosion. Changes in water flow and water level will also lead to changes in the transportation of sediments.
During the construction phase the transport of mud and sediments will be especially large downstream from the construction area. Excavation and tunnelling may lead to greatly reduced water quality and problems for those dependent on the water

.

GROUNDWATER
The groundwater level is important for the ecosystem‘s composition and development of plant and animal species. Groundwater is particularly important as a drinking-water source in most countries. The filling of a reservoir of hydro power plant and the flow of a watercourse are of great importance to the groundwater level and for the feeding of the groundwater reservoirs. A reservoir, together with the changes and variations of the water level caused by its operation, will change the groundwater level in surrounding areas. These areas may in turn influence the quality of the water and the sediment transport of the watercourse as a result of area run-off and erosion.

EXCESSIVE FERTILIZATION
Whenever nutrients are trapped in a reservoir, the result may be excessive fertilisation - eutrophication - in the reservoir. It may lead to an increased growth of algae or large amounts of higher-order aquatic plants. A substantial production of organic matter in the reservoir, or the supply of external organic matter, may cause anaerobic conditions - lack of oxygen - in the deep-water layers.
On the whole, shallow lakes with a large surface area are most at risk, partly because the reserve of oxygen in the deep-water layers is limited in proportion to the productive area in the top layers. In deep, narrow lakes the oxygen content in the deep-water layers will be sufficient to recycle organic matter sinking down, provided there is a regular circulation of the waters. This is not always the case in the tropics. If the watercourse is initially rich in nutrients, the risk of eutrophication will increase.
Evaporation may cause a concentration of nutrients, leading to excessive fertilisation or eutrophication. Tropical soil normally has-a low humus content. This, combined with the great seasonal variations as to the amount of precipitation, and the fact that precipitation often comes in heavy showers, may cause considerable erosion. The transportation of eroded sediments will be halted and deposited in a reservoir. The reservoir’s lifetime may in this way be reduced. Transport of sediments and nutrients tends to play a crucial role in the ecosystem of a watercourse. The population’s utilization of nature and natural resources may be completely dependent on floods and waterborne sediments and nutrients.

TRANSPORT OF NUTRIENTS
A reservoir serves as a trap for nutritious elements and mud flowing in, possibly leading to a considerable reduction of the total transport of nutrients downstream. In addition, the annual variations in supply downstream may undergo changes. This may reduce the biological production all the way to the sea. There are grave examples of marine fishing being impaired in the wake of a major dam development.

FISH
The composition of fish species may be altered, since reproduction for some species may be hindered if the operation involves changes in the water level during the spawning period. Artificial reservoir tends to contain a less varied composition of species than a natural lake. Changes in the water flow and water-flow pattern may radically alter nutrient and spawning conditions downstream. The primary production as well as the direct accessibility of nutriment for fish will change. Changes made to the downstream floods, as a result of water control, may be decisive. At dam and turbine outlets a surfeit of gas may occur, principally of nitrogen, which can cause death among fish.

Some hydro power plants are equipped with fish ladders.

FLORA AND FAUNA
Submerging and water-flow changes, moreover, will lead to changes in the fauna and vegetation beyond the watercourse as such. Large reservoirs will exert a considerable direct impact on the flora and fauna of the hydro power plant area through submerging the area permanently or periodically. Animals may to some extent move to new habitats beyond the reservoir area, provided that suitable conditions are to be found. But normally the types and species of nature existing in areas being submerged must be considered as lost.
It is difficult to predict in general terms how changes beyond the submerged area will turn out. Local climatic changes and changes to the ground-water level may affect the flora and fauna. Valuable types and species of nature may be lost. A general activity increase in the area, such as traffic, noise etc., may also affect the fauna in a negative way. This especially pertains to the construction period.
Further, a reduced water flow or changed flow pattern downstream may influence the flora and fauna. The effects may be direct ones in that the flora and fauna react to the water flow, or the effects may be indirect owing to changes in the ground-water level and the transport of nutrients.

.

۱- از سال ۵۹ تا ۷۹ یعنی بیست سال تمام مخزن سد سفید رود تخلیه رسوبات می شد که اگر خواستید براتون می نویسم ولی تا سال ۷۶ کسی خیلی به اثرات زیست محیطی اون واقف نبود و لی کم کم سرو صداها بلند شد و اولین اونهاهم سیل و تخریب زمینهای کشاورزی حاشیه رودخانه بود بعدهم نابودی آبزیان و جلوگیری از تخم ریزی ماهیها .

الف - میدونید در خرداد ماه هر سال که مخزن پر از آب می شد یک زلزله خفیف (القائی ) رخ می داد و در سال ۶۸ یعنی پس از ۹ سال از رسوب زدائی (شاس) زلزله بزرگ رود بار با ۴۰۰۰۰ کشته روی داد یعنی گسل رود بار با این زلزله القائی فعال شده بود .!

ب- میدونی تا قبل از سال ۷۹ چرا هوای تهران فقط در زمستان ها آلودگی شدید داشت واعلان حالت بحرانی می شد ؟ همین رسوب زدائی مخزن سد سفید رود بود بود !

ج- می دونی چرا دیگه بانک جهانی دیگه برای ساخت سد های بزرگ وام نمی دهد؟