VIRTUAL WATER



Virtual Water is the water embodied in a product not in real sense but in virtual sense.

The water required to produce a product is known as virtual water.

It is also known as embedded water or exogenous water. Exogenous water is the water that the countries import in virtual sense and it is exogenous to the importing countries.

In quantitative term one approach defined the virtual water content as volume of water that is used in actual to produce the product. It depends on production conditions such as time and place of production and water use efficiency. e.g. for producing 1 kg of grain in arid environment requires two to three times more water than growing the same grain in humid country.
In second approach virtual water is defined with the perspective of user. It is defined as amount of water that would have been required to produce a product at the location where it is produced. 

VALUE OF VIRTUAL WATER
  • In water scarce conditions import of virtual water in water deficient country reduce the pressure on water resources.
  • Virtual water can be seen as alternative source of water.
  • Virtual water can be used as an instrument to solve the geopolitical problems and water wars. 
  • By exporting virtual water products the nations get economic benefits
  • Virtual water trade from high water productive nations to low water productive nations implies real water savings
  • Water Footprint is making a connection between consumption pattern and impacts on water.


FACTORS TO QUANTIFY THE VIRTUAL WATER CONTENT OF PRODUCTS 
  • Virtual water content determination is not an easy task. It depends on many factors such as:
  • The place and period
  • The point of measurement (e.g. either water use is measured at water withdrawal point or at field level).
  • The production method and efficiency of water use.
  • The method of attributing water inputs to intermediate products to virtual water content of final products.

HOW WALK MAKES HEALTHY AND FIT



Walking makes us healthy. It maintains and improve our health. Walking can be done any time in a day and it requires less or no equipment. A study conducted in 2007 about inactive women depicts that even 75 minutes walk per week makes the person fit as compared to non exercising groups. Walking is a great form of physical activity for the people who are overweight, elder and who have not walked for long time. 

HEALTH BENEFITS FROM WALKING

The benefits gained from walking are as follows:

  • increased cardiovascular and pulmonary fitness
  • strong bones, improve balance
  • increase muscles strength
  • reduce body fat
  • improved management of conditions such as hypertension, diabetes, high cholesterol, high muscular pain
  • walking makes you happy
  • walking boosts vitamin D
  • It prevents dementia
  • It tones up legs, bums and tums
  • It gives us energy
Different studies show that regular exercise lowers the risks to certain cancers  such as breast and colon cancers.

PEDOMETER USE

A pedometer is used to measure that how much steps a person walks. A person should wear it while walking. It motivates the people to do more walk and do better than before. 

WALKING TIME

Walking for 30 minutes is beneficial for health. Moderate walking poses the little risks to health but patients must consult with doctor before initiating any new program of health exercise. It is difficult to walk for continuous 30 minutes. but to make it a habit you can start with dividing them into three sessions each of 10 minutes in day. Gradually it becomes a habit. In case for the purpose to lose the weight exercise  must be done for more than 30 minutes in a day but here also the habit is built gradually by starting the walk for less time than increasing the time.

To build the walking routine some suggestions are as follows:
  • Walk to shops rather than by drive
  • Walk the dog
  • Get off local transport and walk to home or office 
  • Take the stairs instead of lift

Spaghetti with Asparagus, Egg, and Parmesan: a Mutant Freak of Deliciousness

Though I’m cooking more often now, creating my own recipes continues to scare the living daylights out of me. My self-spawned dishes tend to be three-out-of-five star affairs, meaning they’re servable, but won’t necessarily knock your socks off. See, I’m still mastering certain techniques (read: all of them), and find pairing flavors tougher than Advanced Calculus. (Hey, if mathematicians had to eat their results, they’d have never picked up calculators in the first place.)

So, when I invent something that actually works, it’s like … it’s like … hm … how to express this without resorting to hyperbole?

Oh! I have it. It’s like riding a golden unicorn over a rainbow while world peace breaks out in the background. Or U2 playing an acoustic gig in my living room as I’m hand-fed chocolate-covered strawberries by Raoul Bova. Or taking a permanent vacation from my job, but with eternal severance pay and health benefits. (Dare to dream.)

Okay, maybe I’m exaggerating. But it is pretty cool. And today’s recipe, Spaghetti with Asparagus, Egg, and Parmesan, is one of those rare triumphs.

Tuesday night, I was in a spaghetti mood, but had a use-it-or-lose-it pound of asparagus whiling away in the crisper drawer. With no funghi available,Pasta with Asparagus and Mushrooms was out of the question. So was Roasted Asparagus with Poached Egg and Parmesan, since I reallyreallyreally wanted some pasta. But both recipes fused together? That could work.

And did it EVER. It’s my new favorite comfort food. Creamy and cheesy and asparagus-y, I can see myself eating this over and over again until my death in 2097. (Yes, I’m shooting for 120. Believe in the stars!) And? AND? I would say I could eat 14 bowls of the stuff, but a single serving filled me to the brim.

Of course, should you decide to give it a shot:

1) To cut the fat even further, omit ½ tablespoon olive oil and a little parmesan.

2) Don’t throw out the pasta water. Love it. Be liberal with it. It’s vital to everything.

And that’s it, folks. Have a lovely weekend, and experiment if you get the chance. Occasionally, it’s worth it.

GROUND WATER SOURCES GENERAL REMARKS

The water that is percolated in the ground is known as groundwater. 
It is brought on the surface for use. The following points need to be taken into account regarding underground sources:

a) AQUIFERS

The surface of each aquifers is composed of alternate pervious and impervious layers. Pervious strata are those strata through which water can easily pass while impervious strata are those through which water cannot pass. 

The pervious layers are named as aquifers or water holding strata. Aquifers have sand or gravel layer that provides the good quality water. The aquifers that are made of limestone layer gives good quantity of water supply and cracks or fissures are present there.

b) MOVEMENT OF GROUNDWATER

The movement of underground water is through gravity and attraction of molecules of surface tension.

c) POROSITY 

The porosity is defined as the ratio of volume of pores or openings of material to the volume of total volume of material. Porosity is measured in percentage. 

P= V1/V2×100

P= Porosity of soil
V1=  Volume of openings of material
V2= Total Volume of  material

Name of Rock or Soil                                          Porosity in %

Clay                                                                         44-47          
Chalk                                                                      14-15          
Limestone                                                              0.5-17          
Sand and Gravel                                                    35-40          
Sandstone                                                                 4-30          
Compacted Sand and Gravel                               25-30          
Top Soils                                                                 37-65          

d) QUALITY OF WATER

The process of natural filtration occurs when rainfall occurs and rain water percolates through the ground.That's why underground water is free from impurities.Some quantity of bacteria are also present in water. that protect the water from contamination. The groundwater contains different salts depending upon the type of strata and length of underground water flow. The minerals present in underground water are manganese, magnesium, calcium, potassium, sodium and iron. 

Rocky strata give more or less pure water.
water with clayey soil have high turbidity.
Aquifers made of limestone provides long passage of underground water.

e) WATER TABLE

The upper top soil at ground level is pervious and the rain water is percolated through this pervious layer and gathered here.This upper surface of free water is called as Water table of groundwater table.

Water table level changes. It increases in the wet season and falls down in dry season. 

SOLID WASTE ANALYSIS DESIGN AND PLANNING


The second step in waste characterization is analysis design and planning. 

1. TYPE OF SAMPLING

A sample is a subset of a population that represents the results of whole population. It is necessary to take the sample of waste because it is no possible to analyze the whole population.

Stratified random samples must be used as much as possible. Relevant sources of waste must be sampled from any selected strata. For Example waste bins are able to be sampled from selected strata.

2. NUMBER AND TYPE OF STRATA

The number and kind of strata to be used depends on many factors: waste management information, sufficient resources, need of municipality and availability of sufficient waste planning data. 

Maximum five strata could be used. Above than 5 strata's could lead to requiring more sampling from waste to achieve accuracy in results. More sampling would be time requiring so it is preferred to take 5 strata's not more than this. 

It is more helpful to make a stratification matrix at initial planning stage that provides the necessary data and information for stratification.

3. LEVEL OF SAMPLING

At three levels sampling could be done:
  • Inside household or business e.g. from the internal waste bins
  • Outside household or business e.g. from the external waste bins used for kerbside collection
  • A refuse collection vehicle
It is recommended to use external waste bins outside households and business.


Criteria for Level of Sampling
  • Sample level must fulfill the statistical requirement.
  • Sample leveling should not compromise the  manual sorting procedures
  • Allow correlation and evaluation of household level stratification criteria
4. TYPE OF SAMPLING UNIT

There are 3 main sampling units
  • waste bin with volume of 240 liters
  • specific waste of household or commercial waste with 100 kg weight
  • specific number of persons generating that waste e.g. 30 persons
It is recommended to use volume of waste bin but it is noted that it does not mean the volume of waste within the bin.

5. CALCULATION OF NUMBER OF SAMPLING UNITS AND SAMPLE SIZE

Total number of sampling unit depends on:
  • Variation of waste
  • Accuracy of results
If the variation coefficient of waste is unknown than for different type of waste following sample size must be used
  • household waste 45 meter cube
  • mixed household/commercial waste 80 meter cube
  • commercial waste 100 meter cube
6. DURATION OF WASTE COLLECTION CAMPAIGN

Municipal waste collection should be done on weekly or daily basis. 

It is recommended that waste sampling must cover a week waste e.g. sampling from Monday to Friday covers a full collection cycle and variation due to non collecting waste at weekends .

EXECUTION AND EVALUATION OF WASTE ANALYSIS

EXECUTION OF WASTE ANALYSIS

Execution of waste analysis is the third step in waste characterization.

1. COLLECTION OF SAMPLES
  • The Collection team should collect the waste either by emptying the waste containers or by exchanging them with empty ones on regular intervals without informing the property holder who produce this waste to avoid his influence in changing the composition of waste.
  • Each sample should be tagged with a specific reference identification code so that it could be used in wet conditions.
  • The following data must be recorded while collecting waste samples
1)  Sample Address 
2)  Date of Collection
3)  Specific Identification Reference Code
4)  Number and type of waste containers collected
5)  Estimation by seeing the percentage filling level of containers
6)  Estimation of percentage filling level of  other containers at one address for finding the waste amount
  • Number of persons responsible for waste production and collection interval information are useful to give the indication of per capita waste statistics and per household waste statistics.
  • Every waste sample collected must not to be mixed with other waste sample
2. SORTING AND ANALYSIS OF SAMPLES

Each sampling unit is weighed and weight is noted. The sorting of each sampling unit is done separately. The sampling unit is sorted according to a sorting catalog. The catalog will be described in later posts. The catalog has 13 primary waste categories and 35 secondary categories.

Sorting Procedure
  • A waste analysis record sheet (paper copy) is prepared for each sampling unit.
  • The unique code for waste is noted for each sample against waste analysis record.
  • The percentage filling ratio of waste containers is recorded.
  • The sampling unit is weighed with an accuracy of +/- 0.1 kg is recorded.
  • The sorting units can be separated into two fractions above 40 mm and below 40 mm waste category through screens or by screen table. This reduces the effort of sorting.
  • The above 40 mm fraction is sorted into 12 waste primary categories.
  • The below 40 mm fraction is further sorted into two fractions above 10 mm and below 10 mm through 10 mm mesh screen.
  • The below 10 mm waste weight is recorded and considers as "Fines" category.
  • The 10-40 mm waste is weighed too.
The sorting rate recommended is 6 man-hours (sorting team
members) per 100 kg of waste.

EVALUATION OF WASTE ANALYSIS

The evaluation of waste analysis depends upon weight results taken while sorting procedures from all sampling units.

The basic weight results should be transferred from record sheet to excel sheet that will easily calculate the waste composition and required statistical data.

Sample Analysis

Physical analysis is useful in determining the composition o municipal solid waste. Sorting is done for easy handling and management of waste. Water samples are sent to Laboratories for chemical analysis.

Extrapolation

It includes the conclusion from obtained sample results from population.

Presentation of Results

The results presented are:
  • Raw Data
  • Statistical Calculations
  • Evaluation of single results of strata
  • Extrapolation of overall results and waste quantities
  • Graphical representation of results

SURFACE WATER RESOURCES AND THEIR WATER QUALITY


SURFACE SOURCES

Surface water resources includes three types of sources

1) Lakes and Streams
2) Rivers
3) Storage Reservoirs

1) LAKES AND STREAMS

A natural lake is a large water body in the land. A lake is used to supply water to its nearest areas. The runoff of water that goes in the lake should be measured correctly and it should be equal to the demand of that area people. Streams are made by the surface. Streams have plenty of water in rainy season but the flow of water in dry season is quite low and it may cause the streams dry. 

The catchment area of both lakes and streams is low. So, the water supply is also low in these water bodies. Therefore, they cannot be used as water supply schemes for large cities. They can only be used for nearby areas and small towns. 

Water Quality
The water of lakes and streams is free from impurities. This water can be utilized safely for drinking water purpose. 

2) RIVERS

Rivers proves as the large source of water supply schemes for Rivers are classified into two categories. Some rivers are perennial that flows throughout the seasons because these are snow fed rivers. Other rivers are Non Perennial rivers that became dry in hot seasons and floods face the rivers in monsoon seasons. It is necessary to utilize the flood water by storing the water in winter through constructing dams and utilize this water in summer. 

The river water can be used for the following purposes:

  • source of water supply for a town
  • used for navigation
  • source of water supply for irrigation
  • used for purification of waste
  • source of recreation activities such as bathing, boating and fishing etc.
Quality of Water


The quality of river water is not consistent. It has silt and suspended impurities. When sewage water (partially or completely treated) is entered into river, then high contamination in rivers is observed. The river water should be analyzed in the perspective of diseases, bacteria and high impurities. River water should be effectively treated before its use as drinking water. Quality of water changes depends upon many parameters such as catchment area, sewage discharges, climate conditions and season of year. The quality of river water is found good at its head and it turns to deteriorating by reaching at its coarse areas. 

Reasons why River Pollution Undesirable

  • Contamination of water leads to increase in pressure on treatment units
  • Effects on fishes life
  • Hindrance of recreational use
  • Hindrance in navigation
  • Irritation by odor and appearance of river water
3) STORAGE RESERVOIRS

An artificial lake made by the construction of dam across a valley is known as storage reservoir. It has three parts:

1) A dam to store water
2) spillway to promote excessive flow of water
3) Gate Chamber having valves to regulate the water flow

These reservoirs present a source of water for large cities. The reservoir water can be used for irrigation and power generation. 

Site Selection for Reservoir

Following points should be considered while selection of a site:
  • land area to be submerged by reservoir construction
  • availability of construction materials
  • elevation of reservoir level
  • availability of skilled labor
  • water quality in reservoir
  • water availability
  • properties of catchment area
  • density of population over catchment area
  • good foundation bed for dams

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