Ruchinilo from IIT Guwahati made an agricultural app for mobile Get Timely Advice & Assistance from Experts

One Man Made an App to Help Farmers Get Timely Advice & Assistance from Experts around the Country

In April 2015, Ruchinilo graduated from IIT Guwahati with a Masters in Development Studies

What’s more impressive is that the entire initiative required no funds: “I have a background in programming and assembled the app myself, using open data sources,” Ruchinilo says.

“If I buy phones to give them, they will have a sense of indebtedness to me. They will think of it as an act of charity and will not have a feeling of ownership, of entitlement about it,” explains Ruchinilo.
Determined to ensure that the farmers developed a sense of ownership about the project and viewed him not as a donor but as a partner in their development, Ruchinilo urged the farmers to pitch in and buy common smartphones or use existing phones for their respective communities.
“I used Information Communication Technology (ICT) in the form of a mobile interface to develop an app for farmers where, if they are facing any problems, they can reach out to experts. They can also use the app to create reports about their farm and build a knowledge bank. This will prove to be very useful to the communities in the future,” he explains.
“The objective is to connect farmers with individuals who are experts in the agriculture sciences in order to promote knowledge sharing and sharing of best farming practices,” Ruchinilo elaborates.

With the app, a farmer can reach out to five experts in different parts of the country. He can communicate using photographs, videos or even text messages in his mother tongue.
Queries and requests for help from the farmers are then picked up by the Cloud. These make their way to Ruchnilio and his team, who filter the messages and direct them to the appropriate experts.
The project was launched in October 2015 and, in just eight months, the app has already met with resounding success. “In the months of January and February, we saw close to five or six queries from farmers a day,” Ruchinilo says.

The app has helped 44 farmers in nine villages across Udaipur district connect with experts who can help them efficiently navigate the choppy waters of being a farmer in India.

Oxytocin “the feel-good” hormone”

Oxytocin “the feel-good” hormone”

Oxytocin has other benefits as well like making you feel more aroused, increasing feelings of trust, lowers heart rate, reduces blood pressure and simply makes you more ready for sexual interaction. 

Skin to skin touching (with intimacy, a massage, intercourse, or cuddling) is all that is required. Also involved in sexual responsiveness and orgasm, the hormone oxytocin counteracts stress and depression by combating the harmful effects of cortisol and reduces blood pressure. It has also been shown to improve gut motility and decrease intestinal inflammation.

One of the most prevalent benefits of sleeping naked is that it let’s your body cool properly at night better. Doing this helps to maintain healthy (more balanced) cortisol levels. Cortisol is also known as the stress hormone as i’m sure you’re aware. The higher your cortisone levels the more you are at risk for certain health conditions. Conditions like high blood pressure, higher than optimal cholesterol levels, as well as other imbalances, weaker immunity and increased appetite which is weight gaining effects. Cortisol is also a fat storing hormone so the higher your cortisol levels the more your body will store fat. The cortisol levels in the body are usually lowest when you are sleeping deeply  (between 10 p.m. and 2 a.m or so) But after deep sleep your cortisol levels start to rise again in order to wake you up in the morning. Want to lower your stress levels and help the body release fat stored by cortisol? Sleeping naked is a step in the right direction. Sleeping naked keeps you cool which helps cortisol levels.

Sleeping naked does in fact stimulate oxytocin which is a feel good hormone. This is also known as the “love hormone” which also happens to be released when you are experiencing sex and orgasm. It is a hormone that helps fight depression as well as contributing to gut health and a healthy blood pressure levels. Sleeping naked with your partner can light the flame and increase your sex-drive and physical connection.

When we sleep in total darkness, melatonin is released, triggering a very slight but critical cool-down in the body. As body temperature drops, growth hormone is released and works its regenerative magic.

6 amazing health benefits of sex in a loving relationship

Majority of relationship therapists will tell you that not having sex with your partner frequently enough (at least twice a week) will make either or both of you unhappy, frustrated, depressed. Research shows people who have intercourse (not masturbation) at least once or twice a week are better placed to live longer due to the companionship, happiness and pleasure they both bring.

One passionate sex session and all your problems are gone.

1.      Sex helps your heart: Having sex at least twice a week will heavily reduce your chances of having a heart attack and helps maintain a healthy heart.

2.     Sex relieves stress and tension: This is because the feel good hormones – endorphins and oxytocin – are released during sex.

3.     Sex relieves pain: Studies show that after you orgasm, the hormones released will actually help stop your pain; headaches or any other body pains.

4.     Sex makes you feel and look great: The more sex you have the more hormones like testosterone and estrogen are released into the body and this helps keep your body looking young and fresh. If you want softer skin and shiny hair, then estrogen is your answer.

5.     Sex helps you sleep better : A relaxed sex session, which results in an orgasm, will release the hormone prolactin. This is the hormone that is heavily linked to a good night sleep.

6.     Sex fights disease: People who have frequent sex have a higher level of an antibody called immunoglobulin A (IgA). According to research, these antibodies help combat diseases 

7.       SOURCE OF THE ARTICLLE : https://tuko.co.ke/149926-health-benefits-of-sex-6-ways-that-sex-in-a-loving-relationship-can-amazingly-improve-your-health.html

TANNERY WASTE WATER TREATMENT FLOW CHART WITH ZLD

Source of the article: http://www.slideserve.com/camden/introduction-to-t-he-t-reatment-of-tannery-effluents/?utm_source=slideserve&utm_medium=website&utm_campaign=auto+related+load

Moving Bed Biofilm Bioreactor (MBBR) -Design and Construction Principles of FMR

Moving Bed Biofilm Bioreactor (MBBR) process uses the whole tank volume for biomass growth. It uses simple floating media, which are carriers for attached growth of biofilms. Biofilm carrier movement is caused by the agitation of air bubbles. This compact treatment system is effective in removal of BOD as well as nitrogen and phosphorus while facilitating effective solids separation.

Design and Construction Principles

MBBR units are placed in series based on the load entering each reactor. Neutralised and settled wastewater passes through MBBR for reduction in BOD/COD. Most of the MBBR plants are provided with vertically or horizontally mounted rectangular mesh sieves or cylindrical bar sieves. Biofilm carriers are made up of high density (0.95 g/cm³) polyethelene. These are normally shaped as small cylinders with a cross inside and fins outside. The standard filling of carrier is below 70% with a maximum specific area not more than 465 m²/m³. Generally, design load for COD-BOD removal is 20 g COD / m²d. Smaller carriers need smaller reactor volume at a given loading rate (as g/m²d) when the carrier filling is same. 

It is advisable to use MBBR in combination with a septic tank, DEWATS or a pre-coagulation step as a pre-treatment unit, depending on the local conditions and input characteristics. It is a very robust and compact alternative for secondary treatment of municipal wastewater, having removal efficiency for BOD 90 – 95% (low rate) and that of 75 – 80% for high rate. Average nitrogen removal is about 85%. There is no need for sludge recirculation. Phosphorus and faecal coliform reduction is feasible with additional passive (non-mechanical) or active (mechanical) system components.

A constantly operating MBBR does not require backwashing or return sludge flows. It has minimal head-loss. Coarse-bubble aeration in the aeration zone in the wastewater treatment tank provides ease of operation at low-cost. Agitation continuously moves the carrier elements over the surface of the screen thus preventing clogging. Maintenance of MBBR system includes screening, influent equalisation, clarifier system, sludge handling and integrated control system. There is no need to maintain f/M ratio as there is self-maintenance of an optimum level of productive biofilm. Skilled labour is required for routine monitoring and operations of pumps and blowers.

You always need expert advise to design a efficient and cost effective system.

	ITEMS OF ENVO COMPACT MODULE
Sr No	Item	Specification	Qty	Cost
1	Raw Sewage Pump	Submersible,auto running,kirlosker	1 No
2	Compact module consisting of following units,. 1.Aeration-I with aeration grid 2.Aeration-II with aeration grid 3.Tube settler with baffle and weir 4.Treated water tank 5.Sludge holding tank with aeration	MS with support frame, inside FRP, outside painted	LOT
3	Diffuser in Aeration Tank-I & II	Dome type,Make:ENVO	LOT
4	Floating Media in aeration tank-I & II		LOT
5	Tube Deck Media in Tube Settler		LOT
6	Air Blower,	Twin lobe Rotary type, Make: SGN	1 No
7	Filter Feed Pump	Kirlosker	1 No
8	Pressure sand  filter	MS module with media and frontal pipes and valves,Make:ENVO	1No
9	Activated carbon filter	MS module with media and frontal pipes and valves,Make::ENVO	1No
10	Electric starters,wires	Panel,starter  and wires to pump and blowers	LOT
11	Pipe & Fittings, PVC	PVC pipe and fittings	LOT
12	Sludge Pump	kirlosker pump	1 No
13	Filter Press	PP plates with filter cloth, Make:Saraswati	1 No
14	Erection commissioning of the system		LOT

14+ Tools for Bloggers

source of the article http://www.socialmediaexaminer.com/14-plus-tools-for-bloggers/

Are you a busy blogger?

Looking for new, unique tools to help you work smarter?

The right tools will help streamline and improve your blogging.

In this article, you’ll discover more than 14 tools to help bloggers quickly, efficiently perform common tasks

Screaming Frog SEO Spider Tool

The SEO Spider is a small desktop program you can install locally on your PC, Mac or Linux machine which spiders websites’ links, images, CSS, script and apps from an SEO perspective.

https://www.screamingfrog.co.uk/seo-spider/

DEWATS SLIDES decentralised-natural-waste-water-treatment-system

Source of the article: http://www.slideshare.net/csrwwt/dewats-decentralised-natural-waste-water-treatment-system

DESTINY FATE IN ISLAM IN NUTSHELL

DESTINY FATE IN ISLAM IN NUTSHELL

Tawakkul means putting in one’s best efforts—leaving no stone unturned, and then putting one’s trust in Allah and not in one’s own efforts or availability of the means one has, because whatever the outcome, it comes about only with the approval and decree of Allah and not otherwise. It is reported that one day Prophet Muhammad (SAW) noticed a Bedouin leaving his camel without tying it and he asked the Bedouin, “Why don’t you tie down your camel?” The Bedouin answered, “I put my trust in Allah.” The Prophet then said, “Tie your camel first, then put your trust in Allah.” 

To work and to strive is within the ability and the limits of man..whether the striving is accepted or not, or whether the desired result is achieved or not is entirely in the Blessed Hands of the Lord Most Majestic Who Created Alone!.

OPERATION MANUAL FOR 10 KLD ETP CHEMICAL DOSE OF ALUM

OPERATION MANUAL FOR 10 KLD ETP

OPERATION INSTRUCTION :

1.         The total quantity of waste water from kitchen for which the ETP is designed is 10,000 liter per day. The unit functions 8 hours in a day .There is no flow at day.The ETP is designed for continuous flow treatment of effluent at a average flow rate of 1250 liter per hour. The air blower will have to be run continuously for mixing of chemicals in reaction tank and flocculation tanks.

2.         Allow all the effluent of the day generated to enter the underground collection tank. Collected effluent is planned to be pumped continuously for eight hours at a average flow rate of 1250 liter per hour . The plant and machinery cant take more than this flow.

.

CHEMICAL DOSING  :

1.   Lime, add 20 Kg per day to maintain pH at 10 at collection tank. Check pH at Collection tank after adding lime manually. pH maintaining is extremely important or alum will not work properly. Use it up in one day.

2.    Alum, add 15 Kg in the auto doser tank of the reaction tank in 100 liter of water and use it up in one day. pH will come down to 8 after addition of alum.

3.   PAC, add 100 gm in the auto doser tank in the flocculation tank and use it up in one day.

COMMON INSTRUCTION FOR ETP  :

1.   When the pumps are on, the blower must be on also for mixing the chemicals with water. Note down the time in log sheet.

2.   The Auto doser for alum in reaction tank should be on when pump is on. Note down the time in log sheet

3.   The Auto doser for PAC in flocculator should be always on continuously when pump is on. Note down the time in log sheet

4.   Fill the auto doser tank with fresh water and mix the estimated chemical in it for the day and set it at the desired dose. Note down the time and quantity in log sheet

5.   Preventive maintenance of pumps and blowers like oiling etc should be regularly done.

6.   Note down the pH of the inlet and outlet water and note it at log sheet.

7.   The waste sludge from tube settler is to be suitably disposed off to the sludge drying bed by opening the valve provided at the hopper bottom of the tube settler.

8.   Backwash the Sand filter and carbon filters after each 4 hours.

9.   Raw and treated effluent is to be analyzed periodically for pH, TSS, BOD and O&G. .

10.Skilled Operator will be required  to carry out all these instructions.

11.The operator will maintain a log book. And chemical stock registers.

12. The performance of the ETP is dependent on the proper skill of the operator and proper chemical dosing.

Polishing pond for Magur fish in ETP treated water.

Polishing pond for Magur fish in ETP treated water.

 Oxygen level in the tanks should exceed 3 mg/l. If the magur fish tanks are supplied with turbid water it is advisable to filter it with through a sand filter and to aerate the tanks at night for maintaining oxygen level by using an air blower The aeration grid should be one feet above the bottom of the tank so that mud can settle at the bottom..Magur requires mud. .

A tank containing such a fish group required approximately 5 liter/min water supply. Depth of fish tanks should be 0.5–0.75 m. Let us take water depth 0.75 meter.The freeboard of the tank should be 0.5 meter so that fish don’t jump out. So total depth of tank is 1.25 Meter. Volume of the tank should be 10,000 liter. Normally it should be square in size. So length and width of tank will be 4 Meter by 4 meter. 

For avoiding the direct contact between tank wall and fish it is better to cover the inner surface of tank with polyethylene sheet.

Inlet water should be sprayed in the tank from a perforated PVC tube throughout the length.

Outlet water will overflow from a overflow weir at the outlet side. The top of the overflow weir will be covered by net/mesh. The proper mesh size is 1.0–1.5 mm

Most efficient way of plankton maintenance is frequent manuring with small doses of poultry or cattle manure. In addition to plankton maintenance, frequent manuring maintains an active and effective bacterial population in pond water. It facilitates decomposition of metabolites hampering fish growth. Poultry (5–15 kg/bigha) or cattle (10–20 kg/bigha) manure is sufficient for frequent treatment of pond.

Daily brushing of wall and bottom of the tanks is essential. Moreover, when there is deterioration in water quality, 10–20 % fresh water replacement is suggested.

Lime is used for killing different living organisms remaining in muddy pools after dewatering of ponds.

IF MAGUR SURVIVES IN THE POLISHING TANK, IT MEANS THE ETP IS RUNNING PROPERLY.

TANK SIZE : 4 x 4 x 1.25 Meter. Water depth = 0.75 Meter. Free Board=0.5 M

THE COMPLETE GUIDE OF WATER TREATMENT IN SLIDE SHOW.Monroe L. Weber-Shirk S chool of Civil and Environmental Engineering Water Treatment

THE COMPLETE GUIDE OF WATER TREATMENT IN SLIDE SHOW.THE BEST I HAVE SEEN YET

Watch the slide show at the URL given
http://slideplayer.com/slide/5014325/#.Vx9hmpV99aw.facebook

Monroe L. Weber-Shirk S chool of Civil and Environmental Engineering Water Treatment 

• Slide 1

  Monroe L. Weber-Shirk S chool of Civil and Environmental Engineering Water Treatment 

  Slide 2

  Reflections ä What are the two broad tasks of environmental engineers? ä What is the connection between the broad tasks of environmental engineers and building a water treatment plant? ä Why may the water need to be changed/treated? ä What are the two broad tasks of environmental engineers? ä What is the connection between the broad tasks of environmental engineers and building a water treatment plant? ä Why may the water need to be changed/treated?

  Slide 3

  Simple Sorting ä Goal: clean water ä Source: (contaminated) surface water ä Solution: separate contaminants from water ä How? ä Goal: clean water ä Source: (contaminated) surface water ä Solution: separate contaminants from water ä How?

  Slide 4

  Where are we going? particles dissolved chemicals pathogens ä Unit processes* designed to ä remove ___________ ä remove __________ ___________ ä inactivate __________ ä *Unit process: a process that is used in similar ways in many different applications ä sedimentation ä filtration ä... ä Unit processes* designed to ä remove ___________ ä remove __________ ___________ ä inactivate __________ ä *Unit process: a process that is used in similar ways in many different applications ä sedimentation ä filtration ä...

  Slide 5

  Unit Processes Designed to Remove Particulate Matter ä Screening ä Sedimentation ä Coagulation/flocculation ä Filtration ä slow sand filters ä rapid sand filters ä diatomaceous earth filters ä membrane filters ä Screening ä Sedimentation ä Coagulation/flocculation ä Filtration ä slow sand filters ä rapid sand filters ä diatomaceous earth filters ä membrane filters

  Slide 6

  Conventional Surface Water Treatment Screening Coagulation Flocculation Sedimentation Filtration Disinfection Storage Distribution Raw water Alum Polymers Alum Polymers Cl 2 sludge

  Slide 7

  Screening ä Removes large solids ä logs ä branches ä rags ä fish ä Simple process ä may incorporate a mechanized trash removal system ä Protects pumps and pipes in WTP ä Removes large solids ä logs ä branches ä rags ä fish ä Simple process ä may incorporate a mechanized trash removal system ä Protects pumps and pipes in WTP

  Slide 8

  Sedimentation ä the oldest form of water treatment ä uses gravity to separate particles from water ä often follows coagulation and flocculation ä occurs in NYC’s __________ ä the oldest form of water treatment ä uses gravity to separate particles from water ä often follows coagulation and flocculation ä occurs in NYC’s __________ reservoirs

  Slide 9

  Sedimentation: Effect of the particle concentration ä Dilute suspensions ä Particles act independently ä Concentrated suspensions ä Particle-particle interactions are significant ä Particles may collide and stick together (form flocs) ä Particle flocs may settle more quickly ä Particle-particle forces may prevent further consolidation ä Dilute suspensions ä Particles act independently ä Concentrated suspensions ä Particle-particle interactions are significant ä Particles may collide and stick together (form flocs) ä Particle flocs may settle more quickly ä Particle-particle forces may prevent further consolidation

  Slide 10

  How fast do particles fall in dilute suspensions? Gravity Fluid drag ä What are the important parameters? ä Initial conditions ä After falling for some time... ä What are the important forces? ä _________ ä __________ ä What are the important parameters? ä Initial conditions ä After falling for some time... ä What are the important forces? ä _________ ä __________

  Slide 11

  projected Sedimentation: Particle Terminal Fall Velocity Identify forces

  Slide 12

  Particle Terminal Fall Velocity (continued) Force balance (zero acceleration) We haven’t yet assumed a shape Assume a _______ sphere

  Slide 13

  Drag Coefficient on a Sphere laminar turbulent turbulent boundary Stokes Law

  Slide 14

  Drag Coefficient: Equations Laminar flow R < 1 Transitional flow 1 < R < 10 4 Fully turbulent flow R > 10 4 General Equation

  Slide 15

  Example Calculation of Terminal Velocity Determine the terminal settling velocity of a cryptosporidium oocyst having a diameter of 4  m and a density of 1.04 g/cm 3 in water at 15°C [  =1.14x10 -3 kg/(sm)]. Reynolds? Work in your teams. Use mks units (meters, kilograms, seconds). Convert your answer to some reasonable set of units that you understand. Solution

  Slide 16

  Sedimentation Basin Settling zone Sludge zone Inlet zone Outlet zone Sludge out ä long rectangular basins ä 4-6 hour retention time ä 3-4 m deep ä max of 12 m wide ä max of 48 m long ä long rectangular basins ä 4-6 hour retention time ä 3-4 m deep ä max of 12 m wide ä max of 48 m long We can’t do this in our laboratory scale plants!

  Slide 17

  Sedimentation Basin: Critical Path Horizontal velocity Vertical velocity L L H H Sludge zone Inlet zone Outlet zone Sludge out A = WH Q = flow rate What is V c for this sedimentation tank?

  Slide 18

  Sedimentation Basin: Importance of Tank Surface Area L L H H W W Suppose water were flowing up through a sedimentation tank. What would be the velocity of a particle that is just barely removed? Want a _____ V c, ______ A s, _______ H, _______ . smalllarge Time in tank smalllarge

  Slide 19

  Lamella ä Sedimentation tanks are commonly divided into layers of shallow tanks (lamella) ä The flow rate can be increased while still obtaining excellent particle removal ä Sedimentation tanks are commonly divided into layers of shallow tanks (lamella) ä The flow rate can be increased while still obtaining excellent particle removal Lamella decrease distance particle has to fall in order to be removed

  Slide 20

  Settling zone Sludge zone Inlet zone Outlet zone Design Criteria for Sedimentation Tanks Minimal turbulence (inlet baffles) Uniform velocity (small dimensions normal to velocity) No scour of settled particles Slow moving particle collection system Q/A s must be small (to capture small particles) This will be one of the ways you can improve the performance of your water treatment plant. ä _______________________________

  Slide 21

  Sedimentation of Small Particles? ä How could we increase the sedimentation rate of small particles? Increase d (stick particles together) Increase g (centrifuge) Decrease viscosity (increase temperature) Increase density difference (dissolved air flotation)

  Slide 22

  Particle/particle interactions ä Electrostatic repulsion ä In most surface waters, colloidal surfaces are negatively charged ä like charges repel __________________ ä van der Waals force ä an attractive force ä decays more rapidly with distance than the electrostatic force ä is a stronger force at very close distances ä Electrostatic repulsion ä In most surface waters, colloidal surfaces are negatively charged ä like charges repel __________________ ä van der Waals force ä an attractive force ä decays more rapidly with distance than the electrostatic force ä is a stronger force at very close distances stable suspension

  Slide 23

  Energy Barrier ä Increase kinetic energy of particles ä increase temperature ä stir ä Decrease magnitude of energy barrier ä change the charge of the particles ä introduce positively charged particles ä Increase kinetic energy of particles ä increase temperature ä stir ä Decrease magnitude of energy barrier ä change the charge of the particles ä introduce positively charged particles + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + Layer of counter ions van der Waals Electrostatic

  Slide 24

  Coagulation ä Coagulation is a physical-chemical process whereby particles are destabilized ä Several mechanisms ä adsorption of cations onto negatively charged particles ä decrease the thickness of the layer of counter ions ä sweep coagulation ä interparticle bridging ä Coagulation is a physical-chemical process whereby particles are destabilized ä Several mechanisms ä adsorption of cations onto negatively charged particles ä decrease the thickness of the layer of counter ions ä sweep coagulation ä interparticle bridging

  Slide 25

  Coagulation Chemistry ä The standard coagulant for water supply is Alum [Al 2 (SO 4 ) 3 *14.3H 2 O] ä Typically 5 mg/L to 50 mg/L alum is used ä The chemistry is complex with many possible species formed such as AlOH +2, Al(OH) 2 +, and Al 7 (OH) 17 +4 ä The primary reaction produces Al(OH) 3 Al 2 (SO 4 ) 3 + 6H 2 O  2Al(OH) 3 + 6H + + 3SO 4 -2 ä The standard coagulant for water supply is Alum [Al 2 (SO 4 ) 3 *14.3H 2 O] ä Typically 5 mg/L to 50 mg/L alum is used ä The chemistry is complex with many possible species formed such as AlOH +2, Al(OH) 2 +, and Al 7 (OH) 17 +4 ä The primary reaction produces Al(OH) 3 Al 2 (SO 4 ) 3 + 6H 2 O  2Al(OH) 3 + 6H + + 3SO 4 -2 pH = -log[H + ]

  Slide 26

  Coagulation Chemistry ä Aluminum hydroxide [Al(OH) 3 ] forms amorphous, gelatinous flocs that are heavier than water ä The flocs look like snow in water ä These flocs entrap particles as the flocs settle (sweep coagulation) ä Aluminum hydroxide [Al(OH) 3 ] forms amorphous, gelatinous flocs that are heavier than water ä The flocs look like snow in water ä These flocs entrap particles as the flocs settle (sweep coagulation)

  Slide 27

  Coagulant introduction with rapid mixing ä The coagulant must be mixed with the water ä Retention times in the mixing zone are typically between 1 and 10 seconds ä Types of rapid mix units ä pumps ä hydraulic jumps ä flow-through basins with many baffles ä In-line blenders ä The coagulant must be mixed with the water ä Retention times in the mixing zone are typically between 1 and 10 seconds ä Types of rapid mix units ä pumps ä hydraulic jumps ä flow-through basins with many baffles ä In-line blenders

  Slide 28

  Flocculation ä Coagulation has destabilized the particles by reducing the energy barrier ä Now we want to get the particles to collide ä We need relative motion between particles ä Brownian motion is too slow ä _________ _____________ rates ä __________ shears the water ä Coagulation has destabilized the particles by reducing the energy barrier ä Now we want to get the particles to collide ä We need relative motion between particles ä Brownian motion is too slow ä _________ _____________ rates ä __________ shears the water Differential sedimentation Turbulence

  Slide 29

  Flocculation ä Turbulence provided by gentle stirring ä Turbulence also keeps large flocs from settling so they can grow even larger! ä High sedimentation rate of large flocs results in many collisions! ä Retention time of 10 - 30 minutes ä Turbulence provided by gentle stirring ä Turbulence also keeps large flocs from settling so they can grow even larger! ä High sedimentation rate of large flocs results in many collisions! ä Retention time of 10 - 30 minutes

  Slide 30

  Coagulation/Flocculation ä Inject Coagulant in rapid mixer ä Water flows from rapid mix unit into flocculation tank ä gentle stirring ä flocs form ä Water flows from flocculation tank into sedimentation tank ä make sure flocs don’t break! ä flocs settle and are removed ä Inject Coagulant in rapid mixer ä Water flows from rapid mix unit into flocculation tank ä gentle stirring ä flocs form ä Water flows from flocculation tank into sedimentation tank ä make sure flocs don’t break! ä flocs settle and are removed

  Slide 31

  Jar Test ä Mimics the rapid mix, coagulation, flocculation, sedimentation treatment steps in a beaker ä Allows operator to test the effect of different coagulant dosages or of different coagulants ä Mimics the rapid mix, coagulation, flocculation, sedimentation treatment steps in a beaker ä Allows operator to test the effect of different coagulant dosages or of different coagulants

  Slide 32

  Unit Processes in Conventional Surface Water Treatment ä We’ve covered ä Sedimentation ä Coagulation/flocculation ä Coming up! ä Filtration ä Disinfection ä Removal of Dissolved Substances ä We’ve covered ä Sedimentation ä Coagulation/flocculation ä Coming up! ä Filtration ä Disinfection ä Removal of Dissolved Substances

  Slide 33

  Conventional Surface Water Treatment Screening Coagulation Flocculation Sedimentation Filtration Disinfection Storage Distribution Raw water Alum Polymers Alum Polymers Cl 2 sludge

  Slide 34

  Filtration ä Slow sand filters ä Diatomaceous earth filters ä Membrane filters ä Rapid sand filters (Conventional Treatment) ä Slow sand filters ä Diatomaceous earth filters ä Membrane filters ä Rapid sand filters (Conventional Treatment)

  Slide 35

  Slow Sand Filtration ä First filters to be used on a widespread basis ä Fine sand with an effective size of 0.2 mm ä Low flow rates (10 - 40 cm/hr) ä Schmutzdecke (_____ ____) forms on top of the filter ä causes high head loss ä must be removed periodically ä Used without coagulation/flocculation! ä First filters to be used on a widespread basis ä Fine sand with an effective size of 0.2 mm ä Low flow rates (10 - 40 cm/hr) ä Schmutzdecke (_____ ____) forms on top of the filter ä causes high head loss ä must be removed periodically ä Used without coagulation/flocculation! filter cake

  Slide 36

  Diatomaceous Earth Filters ä Diatomaceous earth (DE) is made of the silica skeletons of diatoms ä DE is added to water and then fed to a special microscreen ä The DE already on the microscreen strains particles and DE from the water ä The continuous DE feed prevents the gradually thickening DE cake from developing excessive head loss ä Was seriously considered for Croton Filtration Plant ä Diatomaceous earth (DE) is made of the silica skeletons of diatoms ä DE is added to water and then fed to a special microscreen ä The DE already on the microscreen strains particles and DE from the water ä The continuous DE feed prevents the gradually thickening DE cake from developing excessive head loss ä Was seriously considered for Croton Filtration Plant

  Slide 37

  Membrane Filters ä Much like the membrane filters used to enumerate coliforms ä much greater surface area ä Produce very high quality water (excellent particle removal) ä Clog rapidly if the influent water is not of sufficiently high quality ä More expensive than sand and DE filters ä Much like the membrane filters used to enumerate coliforms ä much greater surface area ä Produce very high quality water (excellent particle removal) ä Clog rapidly if the influent water is not of sufficiently high quality ä More expensive than sand and DE filters

  Slide 38

  Rapid Sand Filter (Conventional US Treatment) Sand Gravel Influent Drain Effluent Wash water Anthracite Size (mm) 0.70 0.45 - 0.55 5 - 60 Size (mm) 0.70 0.45 - 0.55 5 - 60 Specific Gravity 1.6 2.65 Specific Gravity 1.6 2.65 Depth (cm) 30 45 Depth (cm) 30 45

  Slide 39

  Particle Removal Mechanisms in Filters Transport Attachment Molecular diffusion Inertia Gravity Interception Straining Surface forces

  Slide 40

  Filter Design ä Filter media ä silica sand and anthracite coal ä non-uniform media will stratify with _______ particles at the top ä Flow rates ä 2.5 - 10 m/hr ä Backwash rates ä set to obtain a bed porosity of 0.65 to 0.70 ä typically 50 m/hr ä Filter media ä silica sand and anthracite coal ä non-uniform media will stratify with _______ particles at the top ä Flow rates ä 2.5 - 10 m/hr ä Backwash rates ä set to obtain a bed porosity of 0.65 to 0.70 ä typically 50 m/hr smaller

  Slide 41

  Sand Gravel Influent Drain Effluent Wash water Anthracite Backwash ä Wash water is treated water! ä WHY? ä Wash water is treated water! ä WHY? Only clean water should ever be on bottom of filter!

  Slide 42

  Disinfection ä Disinfection: operations aimed at killing or ____________ pathogenic microorganisms ä Ideal disinfectant ä _______________ ä Disinfection: operations aimed at killing or ____________ pathogenic microorganisms ä Ideal disinfectant ä _______________ inactivating Toxic to pathogens Not toxic to humans Fast rate of kill Residual protection Economical

  Slide 43

  Disinfection Options ä Chlorine ä chlorine gas ä sodium hypochlorite (bleach) ä Ozone ä Irradiation with Ultraviolet light ä Sonification ä Electric Current ä Gamma-ray irradiation ä Chlorine ä chlorine gas ä sodium hypochlorite (bleach) ä Ozone ä Irradiation with Ultraviolet light ä Sonification ä Electric Current ä Gamma-ray irradiation Poisonous gas – risk of a leak

  Slide 44

  Chlorine ä First large-scale chlorination was in 1908 at the Boonton Reservoir of the Jersey City Water Works in the United States ä Widely used in the US ä Typical dosage (1-5 mg/L) ä variable, based on the chlorine demand ä goal of 0.2 mg/L residual ä Trihalomethanes (EPA primary standard is 0.08 mg/L) ä First large-scale chlorination was in 1908 at the Boonton Reservoir of the Jersey City Water Works in the United States ä Widely used in the US ä Typical dosage (1-5 mg/L) ä variable, based on the chlorine demand ä goal of 0.2 mg/L residual ä Trihalomethanes (EPA primary standard is 0.08 mg/L) Pathogen/carcinogen tradeoff Chlorine oxidizes organic matter

  Slide 45

  Chlorine Reactions Cl 2 + H 2 O  H + + HOCl + Cl - HOCl  H + + OCl - ä The sum of HOCl and OCl - is called the ____ ______ _______ ä HOCl is the more effective disinfectant ä Therefore chlorine disinfection is more effective at ________ pH ä HOCl and OCl - are in equilibrium at pH 7.5 Cl 2 + H 2 O  H + + HOCl + Cl - HOCl  H + + OCl - ä The sum of HOCl and OCl - is called the ____ ______ _______ ä HOCl is the more effective disinfectant ä Therefore chlorine disinfection is more effective at ________ pH ä HOCl and OCl - are in equilibrium at pH 7.5 free chlorine residual low +1-2+10Charges Hypochlorous acid Hypochlorite ion

  Slide 46

  EPA Pathogen Inactivation Requirements ä SDWA requires 99.9% inactivation for Giardia and 99.99% inactivation of viruses ä Giardia is more difficult to kill with chlorine than viruses and thus Giardia inactivation determines the CT ä SDWA requires 99.9% inactivation for Giardia and 99.99% inactivation of viruses ä Giardia is more difficult to kill with chlorine than viruses and thus Giardia inactivation determines the CT Concentration x Time Enumerating Giardia is difficult, time-consuming and costly. How would you ensure that water treatment plants meet this criteria? Safe Drinking Water Act

  Slide 47

  EPA Credits for Giardia Inactivation Treatment typeCredit Conventional Filtration99.7% Direct Filtration*99% Disinfectionf(time, conc., pH, Temp.) Treatment typeCredit Conventional Filtration99.7% Direct Filtration*99% Disinfectionf(time, conc., pH, Temp.) * No sedimentation tanks

  Slide 48

  Disinfection CT Credits Contact time (min) chlorinepH 6.5pH 7.5 (mg/L) 2°C10°C2°C10°C 0.5300178430254 115994228134 Contact time (min) chlorinepH 6.5pH 7.5 (mg/L) 2°C10°C2°C10°C 0.5300178430254 115994228134 To get credit for 99.9% inactivation of Giardia : Inactivation is a function of _______, ____________ ______, and ___________. concentrationtime pH temperature

  Slide 49

  NYC CT? Kensico Hillview Delaware Pipeline 21.75 km long 5.94 m diameter peak hourly flow = 33 m 3 /s Delaware Pipeline 21.75 km long 5.94 m diameter peak hourly flow = 33 m 3 /s 3.4 x 10 6 m 3 volume =603,000 m 3 5 hour residence time!

  Slide 50

  NYC CT Problem ä Hillview Reservoir is an open reservoir ä Should the chlorine contact time prior to arrival at Hillview count? ä Hillview Reservoir is an open reservoir ä Should the chlorine contact time prior to arrival at Hillview count? Giardia contamination from Upstate Reservoirs will be decreased, but recontamination at Hillview is possible

  Slide 51

  Ozone ä Widely used in Europe ä O 3 is chemically unstable ä Must be produced on site ä More expensive than chlorine (2 - 3 times) ä Typical dosages range from 1 to 5 mg/L ä Often followed by chlorination so that the chlorine can provide a protective _______ ä Widely used in Europe ä O 3 is chemically unstable ä Must be produced on site ä More expensive than chlorine (2 - 3 times) ä Typical dosages range from 1 to 5 mg/L ä Often followed by chlorination so that the chlorine can provide a protective _______ residual

  Slide 52

  Removal of Dissolved Substances (1) ä Aeration (before filtration) ä oxidizes iron or manganese in groundwater ä oxidized forms are less soluble and thus precipitate out of solution ä removes hydrogen sulfide (H 2 S) ä Softening (before filtration) ä used to remove Ca +2 and Mg +2 ä usually not necessary with surface waters ä Aeration (before filtration) ä oxidizes iron or manganese in groundwater ä oxidized forms are less soluble and thus precipitate out of solution ä removes hydrogen sulfide (H 2 S) ä Softening (before filtration) ä used to remove Ca +2 and Mg +2 ä usually not necessary with surface waters

  Slide 53

  Removal of Dissolved Substances (2) ä Activated Carbon (between filtration and disinfection) ä extremely adsorbent ä used to remove organic contaminants ä spent activated carbon can be regenerated with superheated steam ä Reverse Osmosis ä semi-permeable membrane allows water molecules to pass, but not the larger ions and molecules ä primarily used for desalination ä also removes organic materials, bacteria, viruses, and protozoa ä Activated Carbon (between filtration and disinfection) ä extremely adsorbent ä used to remove organic contaminants ä spent activated carbon can be regenerated with superheated steam ä Reverse Osmosis ä semi-permeable membrane allows water molecules to pass, but not the larger ions and molecules ä primarily used for desalination ä also removes organic materials, bacteria, viruses, and protozoa

  Slide 54

  Conventional Surface Water Treatment Screening Coagulation Flocculation Sedimentation Filtration Disinfection Storage Distribution Raw water Alum Polymers Alum Polymers Cl 2 sludge

  Slide 55

  Summary Clearwell Backwash Lagoon Flocculation Sedimentation Filtration Rapid Mix

  Slide 56

  Cryptosporidium Oocyst

  Slide 57

  Reynolds Number Check R<<1 -6="" 10="" and="" in="" law="" r="1.1" range="" stokes="" td="" therefore="" x="">

  Slide 58

  Diatomaceous Earth DE Clay

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