Tuesday, 23 October 2018

Water Positive Campus

What is Water Positive Campus?

“A commercial or residential developments are said to be water positive when they are creating more water than they are using.
“A water positive campus produces more water than it consumes.”

How can it be Achieved?

There are three ways by which campus can become water positive:

1) Rainwater Harvesting: We have already discussed earlier rainwater potential in India. Harvesting rainwater is the simplest way to conserve water. This water can be used for drinking and other purposes after treatment or it can be transferred to GW recharge pit for groundwater recharge.

2) Wastewater treatment, Recycling and reuse: Recycling wastewater after treatment is next step towards being water positive. About 50 percent of domestic wastewater generated can be reused after treatment. For an efficient treatment, microSTP is a electro-coagulation based low-cost treatment plant which can be installed in small homes to large campuses.

3) Optimizing Water Use: It means reducing the amount of water you consume by installing water-efficient appliances, taps and fittings or limiting your water usage. For an example, replacing ordinary tap with tap aerator can save as much as up to half your water usage. Adopting sensor-based irrigation system (SMART DRIP) for home-garden can save up to 95 percent of water.

Example: A college hostel has the strength of 300 students who stay in the hostel for 300 days a year. The per capita water demand of students is 125 Liters/day. College campus has a rooftop area (5,500 m2) and green area (16,500 m2) available.  The average rainfall in the region is 900 mm.  Is this campus have the potential to become water positive?

Why it is Important?

In India, freshwater resources are depleting every year. Today India is water-stressed and moving towards what's technically termed “water scarcity condition” with a majority of the country. Water positive campus is a sustainable concept which can overcome the water crisis in future in a greener way! 

Wastewater Generation, Treatment and Reuse

In India, wastewater generation from all class-I cities and class-II towns is 38254 MLD and treatment capacity is 11787 MLD, which is about 30 % of total sewage. About 70% of wastewater remain untreated and discharged in water streams like rivers and ocean leaving them polluted.

Average domestic water consumption pattern
In urban India, about 48,000 MLD water is supplied and on average a person uses 165 litres of water per day. The chart and table below show the break up of per capita domestic water use pattern.

Micro STP for Greywater Treatment and Reuse
Greywater is wastewater from non-toilet plumbing fixtures such as showers, basins and taps. Almost 50% of the water supplied for domestic use, comes out as greywater.

         Micro STP is small-scale sewage treatment plant designed for the domestic greywater treatment. Treatment processes, it may employ biological, chemical, mechanical or electrochemical means. The treated water should be free from any kind of harmful bacteria/pathogens, therefore, in addition, disinfection systems may also require with this system, if water is reused indoors.

               Treated greywater can be reused for toilet flushing and laundry which are two of the biggest consumer of the water in an average household. Apart from this,  it can also be reused for other purposes like gardening, car washing, floor mopping etc. Reusing greywater after treatment can reduce per capita water demand by 50 percent or about 80 litres/day.

Environmental Impact
Centralize wastewater treatment is a big challenge as one of the largest issues facing wastewater management facilities is energy consumption. Wastewater treatment consumes almost 3% of the developed nation’s electrical power annually. That is a large expense for the wastewater industry alone. Why not treat the wastewater at a point source and reuse it. Onsite water reuse can not only reduce per capita water requirement but also help in reducing environmental footprint by suppressing the water pollution.

Rainwater Harvesting Potential in India

Water has been considered as a free resource for years. With the rapid growth in population and increasing demand for water on one hand and depletion of available water on the other has led India to acute water stress. This article explains the rainwater harvesting potential in India and how it can save us from becoming water scare nation.

Rainfall In India
On average, India receives about 4,000 cubic kilometres of rains annually or about 1,720 cubic metres of fresh water per person every year, out of which 700 cubic kilometres is immediately lost of the atmosphere, 2150 cubic kilometres soaks into the ground, and 1150 cubic kilometres flows as surface run-off.
More than 70 % of annual rainfall occurs during its monsoon seasons (June to September), with the northeast and north receiving far more rains than India's west and south. India currently stores only 6% of its annual rainfall or 253 billion cubic metres, while developed nations strategically store 250% of the annual rainfall in arid river basins.

Water Demand and Resources
India dedicated about 688 cubic kilometres (84%) to irrigation, 56 cubic kilometres (7%) to municipal and drinking water applications and 69 cubic kilometres (9%) to industries and other applications.

Other than rains, the melting of snow over the Himalayas after winter season feeds the northern rivers to varying degrees. India also relies excessively on groundwater resources, which accounts for over 50 percent of the irrigated area.

Rainwater Harvesting Potential
Based on average annual rainfall and water demand, India has great rainwater harvesting potential to fulfil water needs of all the sectors alone. 

Water Demand in km3
Rainwater Utilization(When 80 % rainwater is harvested)
688910107220.9 %27.5 %32.4 %
Drinking Water
56731021.6 %2.2 %3 %
Industry & Others
691102732 %3.3 %8.3 %
8131093144725 %33 %44 %

Way Forward
It is clearly extrapolated that not even 50 % of rainwater is utilized on combing all the sectors water demand by 2050. This is just rainwater, we have other water resources too. India just needs a proper water management and it will never run out of water for at least 100 years. Water conservation, it all starts with us. Individual contribution is important to protect our natural resources. Use water precisely and save it to use it tomorrow.  

Sunday, 3 December 2017

Why Water Tank Cleaning is Important.

We use water for almost every purposes in our daily life like bathing, cooking, drinking etc. The quality of water really matters when it comes to the health of our loved ones. We invest a lot of money in branded water purifiers to ensure our family health but most of the time we become ignorant when it comes to the hygiene of the water storage tanks.

The water storage tanks in houses, apartment & society are the primary reservoirs which store the water for our daily need. It is very important to maintain hygiene of storage tanks during a period of time to prevent water from contamination and avoid the growth of algae & bacteria within the tank.

Tank cleaning can be done manually or there are many professional services available in the market.

1) Manual Cleaning: In this process, the tank is scrubbed and washed with bare hands. This can be done by anyone. No professional skills are required.

2) Professional Cleaning: The professional tank cleaning services include, jet spay, vacuum cleaning, antibacterial sprays and UV sterilization which ensures the quality cleaning and make tanks safer to store water for longer time.

It does not matter how you are cleaning your tank either by the manual or professional method. The important is that it should be hygienic and free from contamination.  Basically,  it is recommended to clean your water tank every three months.

Sunday, 26 November 2017

Is Alkaline Water Good?

These days we have heard many claims about the alkaline water and its health benefits. Many companies market their product saying it can help in maintaining your body pH level, have anti-aging properties and prevent chronic disease like cancer.   But is alkaline water is good for your health?  Lets find out.

What is Alkaline Water?
Alkaline water is referred to water having pH value greater than 7. Alkaline water typically has a pH between 8-9. pH value is a measure of acidity or basicity of the substance. Pure water free from any kind of impurities have pH value of 7. Many promoters believe that alkalinity in water can help in neutralizing the excess amount of acid in the body and increase the metabolism rate.

What is Body pH and How it is Regulated?
The normal range for pH in your body is between 7.35-7.45 so, very slightly alkaline. At times, this balance can be disrupted by our diet and lifestyle.

pH can go up or down and this is caused by many factors however, when this does occur, the body has mechanisms in which it can attempt to restore balance. Our lungs and kidneys work together  to regulates body pH when the value falls above or below the normal range. It is generally regulated by two processes:

1) Respiratory Compensation: When body experience low pH, lungs start blowing of CO2 by hyperventilation process and when body experience high pH, breathing is slowed down to increase body CO2 level.

2) Renal Compensation: When your body pH is low, kidney will try to excrete H+ and retain HCO3- and when body pH is high kidney will try to retain H+ and excrete HCO3-.

Is alkaline water good?
Now the the next question comes what if we drink slightly alkaline water which can help in neutralizing excess acidity in the body.

The answer is, human body is very complicated. It's not simple as acid and base neutralization reaction. Many health professionals argue against use of alkaline water, saying there isn’t enough research to support the many health claims made by users and sellers. There is no scientific evidence that fully verifies the claims made by supporters of alkaline water.

However on other hand some studies has suggested some health benefits of alkaline water for people who have high blood pressure, diabetes, and high cholesterol. Therefore more research is needed beyond these small studies, specifically into some of the other claims made by alkaline water supporters.

Possible Side Effects 
Drinking alkaline water may have some side effects like lowering stomach acidity, which helps kill bacteria and expel other undesirable pathogens from entering your bloodstream. Too much alkalinity may lead to alkalosis which can affect bone health.

Drinking natural water free from any harmful impurities is always considered safe. Water found in nature is itself alkaline in nature as it passes over rocks and picks up minerals. But health effect of drinking chemically generated alkaline water is still topic of research. Therefore drinking alkaline water for health benefits is not a great idea unless some strong scientific evidence is presented. The best suggestion to maintain your body pH  naturally is by having healthy diet and regular exercise!

Saturday, 25 November 2017

Water for Construction

Water is an important element for life. It is required in almost every process and operation. In construction quality of water plays  an important role, either it is used in concrete or cement mortar or curing. Many times we have seen that in spite of using best material in cement, required results are not achieved. Most of us think that there is something wrong in cement, but we do not consider quality of water being used.

Using bad quality water in construction  may result to:

a) Loosening of  wall
b) Reduction in compressive strength 
c) Dampness persistently
d) Surface efflorescence
e) Corrosion in steel bars

As per IS:456-2000 standards there are listed some checks/tests which one should perform before using the water for construction purposes:

1) pH: The pH values of water shall generally be not less than 6 and not more than 8.

2) Acidity Limit: It should not require more than 5ml of 0.02 normal NaOH to neutralize 100ml sample of water, using phenolphthalein as an indicator.

3) Alkalinity limit: It should not require more than 25ml of 0.02 normal H2SO4 to neutralize 100ml sample of water, using mixed indicator.

4) Permissible limit for solids: The maximum permissible limits for solids are given below: 

Types of solids
Organic solids
200 mg/liter
Inorganic solids
3000 mg/liter
400 mg/liter
2000 mg/liter for concrete not containing embedded steel, and
500 mg/liter for reinforced concrete work
Suspended matter
2000 mg/liter

5) Water should not contain any organic material.

The water that do not conform IS:456-2000 standards is not recommended to be used in construction. Therefore it is recommended to test your water quality before building your dream house.