Despite the truth that water covers about 71% of the earth’s floor, one of the main issues we face right now is water pollution. We have to scale back water air pollution and that’s why there are many solutions to resolve this problem.
Sometimes water is contaminated with chemical compounds similar to oil, harmful micro organism and other microorganisms. When water is contaminated, the water quality deteriorates and usually becomes toxic, negatively affecting animals, plants and the surroundings.
The greatest answer to stop water pollution is to cease it at the supply. Fortunately, there are numerous options to reduce water air pollution, corresponding to wastewater therapy, stormwater administration and water conservation.
Next, we’ll cover what water pollution is, solution of water air pollution, and how to measure water quality.
Table of Contents
What is water pollution?
What causes water pollution?
10 solutions to water pollution
Wastewater Treatment
Reducing plastic waste
Water conservation
Water environment friendly bathrooms
Septic tanks
Do not use your bathroom as a trash can
Stormwater management
Green agriculture and wetlands
Denitrification
Ozone wastewater therapy
How do we check and measure water contamination?
pH Testing
Conductivity, salinity and TDS monitoring
Measuring water temperature
Measuring dissolved oxygen
Assessing turbidity and total suspended solids (TSS)
Chlorophyll fluorescence evaluation
CDOM/FDOM monitoring
Summarizing solution of water pollution
What is water pollution?
Water air pollution is the contamination of any water system or physique of water, from lakes and oceans to groundwater. Thanks to media protection, we are very aware of the issue of water pollution, especially when we are still producing dangerous chemical substances and entering our waters thus inflicting a discount or lack of water use.
When digital pressure gauge is polluted, acids, bases, oxidizers, and compounds such as copper, cadmium, mercury, arsenic, and organic toxins corresponding to benzene, dichloroethane, and ethylene glycol in the sewage can poison aquatic life and have an effect on drinking water sources and scenic landscapes. The natural matter within the sewage is decomposed by microorganisms when consuming oxygen within the water, affecting the life of aquatic organisms. After the dissolved oxygen within the water is depleted, the natural matter undergoes anaerobic decomposition, producing disagreeable gases corresponding to hydrogen sulfide and mercaptan, which further deteriorate the water high quality. It can adversely affect crops and animals (which depend upon unpolluted water) as nicely as the sensitive water environment.
Global warming is rising and it is a downside we can not afford to turn a blind eye to. With climate change and international warming, our precious planet is starting to maneuver toward a water crisis. Our international population is growing, placing demands on water provides, and as a result, we are seeing an increase in waterborne ailments due to the pollution of our waters.
What causes water pollution?
To find a resolution to the problem of water air pollution, we must first perceive what causes it. The causes of water air pollution can range from overdevelopment to improper sewage treatment.
Once the cause of water pollution is decided, solutions can be developed to handle the issue.
Water air pollution can come from any of the following.
Urban improvement
Sewage and wastewater
Mining
Agricultural fertilizers and pesticides
Oil spills
Burning of fossil fuels
Ocean dumping
Sewer leaks
Global warming
Acid Rain
Animal manure
Eutrophication
Radioactive waste
10 solutions to water air pollution
We can divide the water air pollution drawback into 10 major solutions.
Waste water therapy
Reduce plastic waste
Water conservation
Water-saving toilets
Septic tanks
Do not use bogs as rubbish bins
Rainwater Management
Green Agriculture and Wetlands
Denitrification
Ozone Wastewater Treatment
Wastewater Treatment
Treating water before it enters the waterway system could also be the best method to cut back water air pollution – on the source!
Wastewater treatment amenities have the expertise and tools to take away most contaminants via biological, physical and chemical processes. For instance, wastewater therapy allows water to move via completely different disinfection chambers to reduce the toxicity ranges of water contaminants and prevent leakage into the water system.
To guarantee correct operation of wastewater remedy, common upkeep of the tools is required. This includes purposes such as water treatment sensors, which are crucial for measuring and removing contaminants to reduce water pollution.
Water treatment sensors.
pH sensors
Redox potential (ORP) sensors
Conductivity sensors
Dissolved oxygen (DO) sensors
Turbidity sensors
COD sensors
Ammonia nitrogen sensors
Nitrate sensors
Reducing plastic waste
Plastic waste is a big drawback. The proven reality that greater than 10 tons of plastic enter our oceans yearly and that there are expected to be extra plastics than fish by 2050 is alarming! Plastic waste also can corrupt water provides. That’s why it’s essential to reduce back plastic waste and improve sustainability globally.
Plastic bottles and baggage get many of the media coverage, however plastic is entering water methods in ways you can’t all the time see, and certain don’t understand.
Microplastics are a significant problem and are present in
Industrial manufacturing
Synthetic textiles
Clothing
Personal care merchandise (toothpaste, shampoo, and so on.)
To cut back plastic waste in our properties, we will do the following.
Recycle plastic
Use options to plastic, similar to reusable tableware, food baggage, and so forth.
Shop domestically and purchase vegetables and fruits that aren’t packaged in plastic
Buy organic/natural and eco-friendly care merchandise
Water conservation
Do you turn off the tap if you brush your tooth, or turn off the faucet if you wash your hair within the shower?
Water is a scarce useful resource, so limiting the amount of water you employ each day will assist cut back water pollution.
Water environment friendly bathrooms
In the previous, bathrooms used about three.5 gallons of water per flush, however, the EPA (Environmental Protection Agency) has mandated that all bogs can only flush 1.6 gallons of water per flush.
Most houses are now constructed with 2 button bogs, one for small flushes (0.8-1.1 gallons of water) and one for full power (1.6 gallons of water). Water-efficient toilets are a step in the proper course to preserve water and cut back water pollution.
Having a water-efficient toilet can prevent cash, too!
Septic tanks
Septic tanks are a good way to effectively deal with wastewater; separating solids from liquids. Septic tanks degrade solids and permit liquids to circulate into the drainage system via a biological process.
Using a septic tank reduces water air pollution by eradicating pollution already current within the water.
Do not use your rest room as a trash can
Your rest room is not a trash can; it’s used only for human excrement. Avoid flushing wet wipes, diapers and the rest you think of down the bathroom – that’s what a trash can is for.
Flushing these things down the toilet may cause a clog within the drain, so the sewer system doesn’t work correctly. When things are clogged, the water in the wastewater facility or septic tank can’t be cleaned successfully.
Stormwater administration
Another method we will fight water air pollution is to manage stormwater each time potential. Stormwater flows alongside roads and different surfaces and may acquire viruses, micro organism and other harmful pollution before getting into sewers, rivers and ultimately the ocean.
Treatment and administration of stormwater contains reverse osmosis (RO), advanced oxidation and sand filtration.
Green agriculture and wetlands
Agriculture is a trillion greenback industry worldwide, using as a lot as 70% of the floor water provide to satisfy the wants of livestock manufacturing and agriculture.
Because agriculture is such a large trade, it is probably one of the main causes of water air pollution. When it rains, runoff transports pesticides and fertilizers.
Agriculture can be environmentally pleasant and is called green farming. Green farming involves using pesticides and fertilizers that don’t include harmful chemical compounds. It additionally includes planting bushes and creating wetlands to create buffers that filter runoff and water pollution.
Denitrification
When nitrate levels in water are high, it creates the right surroundings for eutrophication or over-fertilization of runoff to happen. This permits algae and phytoplankton within the water to grow rapidly, reducing water quality and exacerbating water pollution issues.
Denitrification is the direct conversion of nitrate to nitrogen. This ecological course of prevents nitrate from leaching into the soil and helps scale back groundwater contamination.
Ozone wastewater treatment
Although this is additionally a type of wastewater remedy, it goes through a unique course of than conventional wastewater systems, which is why it is also important to notice this.
Ozonated wastewater treatment makes use of an ozone generator to break down water contaminants. Ultraviolet (UV) radiation or an exothermic subject contained in the generator converts oxygen into ozone. This course of oxidizes bacteria, organic matter and different water contaminants.
There are also a quantity of options you possibly can tackle yourself to scale back water pollution.
Report water polluters
Check which water line your drain or sewage pump is related to
Never pour oil, fat and grease down the drain
Use phosphate-free laundry detergents and dishwashing detergents
Dispose of medical and chemical waste properly – do not dump drugs in bogs or rivers
Eat extra natural foods
Reduce how a lot meat you eat
Support environmental charities
Avoid single-use plastic products, similar to plastic bottles and plastic meals bags
Always take observe of automobile maintenance to forestall oil leaks
Reduce chemicals and use eco-friendly or natural fertilizers and pesticides
Plant more timber and crops
If you live on the coast or remove plastic from a river near your house, do a beach cleanup
Finally, water air pollution should at all times be at the forefront of your thoughts in your every day actions
How do we test and measure water contamination?
Testing and measuring water quality can tell us if a physique of water is contaminated. ไดอะแฟรม ซีล is certainly one of the most essential ways to protect delicate aquatic environments and provide clear water for a broad range of vegetation and animals, together with people.
There are many ways to measure water quality, including numerous parameters corresponding to pH, conductivity, dissolved oxygen (DO), ORP and temperature.
There are 7 methods we can check water high quality and reduce water pollution.
pH testing
Conductivity, salinity and TDS monitoring
Measurement of water temperature
Dissolved oxygen measurement
Assessing turbidity and TSS
Chlorophyll fluorescence analysis
CDOM/FDOM monitoring
pH Testing
pH fluctuations may be extremely harmful in aquatic methods; secure aquatic environments have pH values between 6.zero and 8.zero. Many elements can alter the pH of an aquatic system, rapidly making a poisonous environment.
pH may be examined utilizing colorimetric or electrochemical methods.
Colorimetric methods embrace pH indicators and litmus paper. They are straightforward to use and cheap, however for correct pH readings, electrochemical strategies similar to pH controller are highly really helpful. The pH meter must be calibrated prior to use.
You can find more information about pH sensors and their different applications right here.
Conductivity, salinity and TDS monitoring
The conductivity of water tells us the quality of the water and also impacts the salinity and TDS (total dissolved solids) of the water. Analyzing water quality could be measured using conductivity, TDS and salinity meters.
Even if each meter measures a special water parameter, the outcomes will collaborate with each other to indicate how a lot water contamination is current.
Measuring water temperature
Temperature is a vital water quality parameter because it impacts different parameters within the water system.
There are a big selection of thermometers, temperature controllers and temperature sensors that may document correct readings.
Measuring dissolved oxygen
Measuring dissolved oxygen in wastewater treatment and water our bodies is essential because DO levels under 6 mg/L can be toxic to aquatic ecosystems.
Most commonly used are DO electrochemical sensors, but optical DO sensors, colorimetric strategies may also be used.
Assessing turbidity and complete suspended solids (TSS)
Turbidity is the degree to which water becomes cloudy and is a crucial test of water quality. tss (total suspended solids) and decaying plant and animal matter can alter turbidity ranges, typically decreasing the amount of light that passes through the water.
A sudden improve in turbidity indicates water contamination, usually caused by the influx of heavy metals and other sewage.
The best approach to measure turbidity is with a turbidity tube or Secchi disc, however for more accurate measurements, a turbidity meter is really helpful.
Chlorophyll fluorescence evaluation
When water bodies turn out to be eutrophic, oxygen ranges are depleted and nitrogen and phosphorus levels increase, creating a toxic environment for crops and animals. Measuring algal growth and water quality might help scale back water air pollution.
Chlorophyll fluorescence is measured with a chlorophyll sensor, which data the share of wet chemistry and lively chlorophyll.
CDOM/FDOM monitoring
CDOM (colored dissolved natural matter) is naturally current in water bodies. UV gentle is absorbed by the natural matter and breaks all the means down to launch the natural contaminant tannin, which makes the water cloudy. Tannins are related to decreasing the pH and depleting the oxygen content material of the water. When CDOM fluoresces, it’s referred to as fluorescent dissolved natural matter (FDOM).
Photoelectric sensors are used to measure CDOM/FDOM. they measure the provision of light and the concentration of dissolved organic matter (DOM).
Summarizing resolution of water pollution
Water air pollution is an extremely necessary problem we are presently going through, which is why options should be developed to protect the aquatic environment, human health, and other animals (and plants) that depend upon water techniques.
Testing totally different water parameters will determine water high quality so that water pollution could be recognized.
If you would like more data on what water high quality testing gear we offer, please be happy to contact Apure. We sit up for answering any questions you would possibly have..
As you try to learn how to deal with #keyword#, try to discover what will work the best over the long term. Normally what goes on is that people perform fantastic with #keyword# for a time and then slip back in to older habits. You should not have that hard a time keeping away from this when you find yourself dependable in your endeavours and are genuinely established to get to where you would like to go. You must not feel too badly whenever things are complicated initially, each and every brand new tactic that you take up will require an interval of realignment. #links# is a superb source when you need some help remaining encouraged.
Despite the truth that water covers about 71% of the earth’s surface, one of many primary issues we face today is water pollution. We have to reduce water pollution and that’s why there are numerous solutions to resolve this drawback.
Sometimes water is contaminated with chemical substances corresponding to oil, dangerous micro organism and other microorganisms. When water is contaminated, the water quality deteriorates and normally becomes poisonous, negatively affecting animals, plants and the setting.
The greatest solution to forestall water air pollution is to stop it on the supply. Fortunately, there are many solutions to reduce back water pollution, similar to wastewater therapy, stormwater management and water conservation.
Next, we’ll cowl what water pollution is, answer of water pollution, and the means to measure water quality.
Table of Contents
What is water pollution?
What causes water pollution?
10 options to water air pollution
Wastewater Treatment
Reducing plastic waste
Water conservation
Water efficient bogs
Septic tanks
Do not use your rest room as a trash can
Stormwater administration
Green agriculture and wetlands
Denitrification
Ozone wastewater treatment
How can we take a look at and measure water contamination?
pH Testing
Conductivity, salinity and TDS monitoring
Measuring water temperature
Measuring dissolved oxygen
Assessing turbidity and total suspended solids (TSS)
Chlorophyll fluorescence evaluation
CDOM/FDOM monitoring
Summarizing answer of water pollution
What is water pollution?
Water pollution is the contamination of any water system or body of water, from lakes and oceans to groundwater. Thanks to media protection, we’re very conscious of the issue of water air pollution, particularly once we are nonetheless producing harmful chemicals and getting into our waters thus inflicting a discount or lack of water use.
When water is polluted, acids, bases, oxidizers, and compounds such as copper, cadmium, mercury, arsenic, and organic toxins corresponding to benzene, dichloroethane, and ethylene glycol in the sewage can poison aquatic life and affect ingesting water sources and scenic landscapes. The natural matter in the sewage is decomposed by microorganisms when consuming oxygen within the water, affecting the life of aquatic organisms. After the dissolved oxygen within the water is depleted, the organic matter undergoes anaerobic decomposition, producing unpleasant gases similar to hydrogen sulfide and mercaptan, which further deteriorate the water quality. It can adversely have an effect on vegetation and animals (which rely upon unpolluted water) in addition to the sensitive water environment.
Global warming is increasing and it’s a problem we can not afford to show a blind eye to. With climate change and international warming, our precious planet is beginning to maneuver towards a water crisis. Our global population is increasing, placing demands on water provides, and consequently, we’re seeing an increase in waterborne ailments as a end result of air pollution of our waters.
What causes water pollution?
To find a answer to the issue of water pollution, we must first perceive what causes it. The causes of water air pollution can range from overdevelopment to improper sewage treatment.
Once the reason for water pollution is decided, options can be developed to address the issue.
Water pollution can come from any of the following.
Urban growth
Sewage and wastewater
Mining
Agricultural fertilizers and pesticides
Oil spills
Burning of fossil fuels
Ocean dumping
Sewer leaks
Global warming
Acid Rain
Animal manure
Eutrophication
Radioactive waste
10 solutions to water pollution
We can divide the water air pollution drawback into 10 primary solutions.
Waste water therapy
Reduce plastic waste
Water conservation
Water-saving bathrooms
Septic tanks
Do not use toilets as rubbish bins
Rainwater Management
Green Agriculture and Wetlands
Denitrification
Ozone Wastewater Treatment
Wastewater Treatment
Treating water before it enters the waterway system could additionally be the most effective way to cut back water pollution – on the source!
Wastewater treatment facilities have the technology and tools to take away most contaminants by way of biological, physical and chemical processes. For example, wastewater remedy permits water to circulate by way of different disinfection chambers to scale back the toxicity ranges of water contaminants and stop leakage into the water system.
To ensure proper operation of wastewater remedy, common upkeep of the tools is required. This includes functions such as water treatment sensors, that are important for measuring and eradicating contaminants to scale back water air pollution.
Water treatment sensors.
pH sensors
Redox potential (ORP) sensors
Conductivity sensors
Dissolved oxygen (DO) sensors
Turbidity sensors
COD sensors
Ammonia nitrogen sensors
Nitrate sensors
Reducing plastic waste
Plastic waste is an enormous downside. The proven fact that greater than 10 tons of plastic enter our oceans yearly and that there are expected to be extra plastics than fish by 2050 is alarming! Plastic waste can also corrupt water supplies. That’s why it’s essential to reduce plastic waste and improve sustainability globally.
Plastic bottles and baggage get many of the media protection, however plastic is coming into water methods in ways you can’t all the time see, and likely don’t understand.
Microplastics are a serious drawback and are found in
Industrial manufacturing
Synthetic textiles
Clothing
Personal care products (toothpaste, shampoo, etc.)
To reduce plastic waste in our properties, we are able to do the following.
digital pressure gauge
Use alternate options to plastic, similar to reusable tableware, meals baggage, and so forth.
Shop domestically and buy vegetables and fruits that are not packaged in plastic
Buy organic/natural and eco-friendly care merchandise
Water conservation
Do you turn off the tap whenever you brush your tooth, or flip off the tap if you wash your hair in the shower?
Water is a scarce useful resource, so limiting the amount of water you use each day will assist reduce water pollution.
Water efficient bathrooms
In the previous, bathrooms used about three.5 gallons of water per flush, nevertheless, the EPA (Environmental Protection Agency) has mandated that every one bathrooms can solely flush 1.6 gallons of water per flush.
Most houses are now built with 2 button toilets, one for small flushes (0.8-1.1 gallons of water) and one for full energy (1.6 gallons of water). Water-efficient bathrooms are a step in the proper path to conserve water and scale back water air pollution.
Having a water-efficient rest room can save you cash, too!
Septic tanks
Septic tanks are a nice way to effectively deal with wastewater; separating solids from liquids. Septic tanks degrade solids and allow liquids to flow into the drainage system via a organic course of.
Using a septic tank reduces water air pollution by removing pollution already current in the water.
Do not use your toilet as a trash can
Your toilet just isn’t a trash can; it is used just for human excrement. Avoid flushing moist wipes, diapers and the rest you think of down the toilet – that’s what a trash can is for.
Flushing these things down the bathroom can cause a clog within the drain, so the sewer system doesn’t work correctly. When things are clogged, the water within the wastewater facility or septic tank cannot be cleaned effectively.
Stormwater administration
Another way we can fight water air pollution is to manage stormwater every time possible. Stormwater flows alongside roads and different surfaces and may gather viruses, micro organism and different dangerous pollution before coming into sewers, rivers and ultimately the ocean.
Treatment and management of stormwater includes reverse osmosis (RO), advanced oxidation and sand filtration.
Green agriculture and wetlands
Agriculture is a trillion greenback industry worldwide, utilizing as much as 70% of the surface water supply to meet the wants of livestock manufacturing and agriculture.
Because agriculture is such a large industry, it is among the main causes of water air pollution. When it rains, runoff transports pesticides and fertilizers.
Agriculture can be environmentally friendly and is named green farming. Green farming includes the use of pesticides and fertilizers that do not include harmful chemical compounds. It additionally includes planting timber and creating wetlands to create buffers that filter runoff and water pollutants.
Denitrification
When nitrate ranges in water are high, it creates the perfect surroundings for eutrophication or over-fertilization of runoff to happen. This allows algae and phytoplankton within the water to grow quickly, lowering water quality and exacerbating water pollution problems.
Denitrification is the direct conversion of nitrate to nitrogen. This ecological process prevents nitrate from leaching into the soil and helps cut back groundwater contamination.
Ozone wastewater therapy
Although that is also a kind of wastewater therapy, it goes via a different process than typical wastewater methods, which is why additionally it is important to notice this.
Ozonated wastewater remedy makes use of an ozone generator to break down water contaminants. Ultraviolet (UV) radiation or an exothermic area inside the generator converts oxygen into ozone. This course of oxidizes bacteria, organic matter and other water contaminants.
There are additionally numerous solutions you can take on yourself to reduce back water air pollution.
Report water polluters
Check which water line your drain or sewage pump is connected to
Never pour oil, fat and grease down the drain
Use phosphate-free laundry detergents and dishwashing detergents
Dispose of medical and chemical waste correctly – don’t dump medications in toilets or rivers
Eat extra organic meals
Reduce how a lot meat you eat
Support environmental charities
Avoid single-use plastic merchandise, such as plastic bottles and plastic meals luggage
Always take note of car upkeep to prevent oil leaks
Reduce chemical substances and use eco-friendly or natural fertilizers and pesticides
Plant more timber and crops
If you reside on the coast or take away plastic from a river close to your own home, do a seashore cleanup
Finally, water air pollution ought to at all times be at the forefront of your mind in your every day actions
How can we check and measure water contamination?
Testing and measuring water high quality can tell us if a body of water is contaminated. Testing water high quality is considered one of the most important ways to guard delicate aquatic environments and supply clear water for a broad range of crops and animals, together with humans.
There are many ways to measure water quality, including numerous parameters corresponding to pH, conductivity, dissolved oxygen (DO), ORP and temperature.
There are 7 methods we are in a position to check water quality and reduce water air pollution.
pH testing
Conductivity, salinity and TDS monitoring
Measurement of water temperature
Dissolved oxygen measurement
Assessing turbidity and TSS
Chlorophyll fluorescence analysis
CDOM/FDOM monitoring
pH Testing
pH fluctuations can be extremely harmful in aquatic techniques; protected aquatic environments have pH values between 6.0 and 8.0. Many elements can alter the pH of an aquatic system, rapidly creating a toxic surroundings.
pH can be tested utilizing colorimetric or electrochemical methods.
Colorimetric methods include pH indicators and litmus paper. They are easy to use and cheap, but for correct pH readings, electrochemical methods such as pH controller are extremely really helpful. The pH meter must be calibrated prior to use.
You can discover more details about pH sensors and their completely different purposes right here.
Conductivity, salinity and TDS monitoring
The conductivity of water tells us the standard of the water and also affects the salinity and TDS (total dissolved solids) of the water. Analyzing water high quality can be measured using conductivity, TDS and salinity meters.
Even if each meter measures a different water parameter, the results will collaborate with one another to point how a lot water contamination is current.
Measuring water temperature
Temperature is a crucial water high quality parameter as a outcome of it affects other parameters in the water system.
There are quite so much of thermometers, temperature controllers and temperature sensors that can document correct readings.
Measuring dissolved oxygen
Measuring dissolved oxygen in wastewater therapy and water bodies is essential because DO levels beneath 6 mg/L can be poisonous to aquatic ecosystems.
Most generally used are DO electrochemical sensors, however optical DO sensors, colorimetric methods can be used.
Assessing turbidity and total suspended solids (TSS)
Turbidity is the degree to which water becomes cloudy and is a crucial check of water quality. tss (total suspended solids) and decaying plant and animal matter can alter turbidity levels, often lowering the quantity of sunshine that passes by way of the water.
A sudden improve in turbidity indicates water contamination, often brought on by the influx of heavy metals and other sewage.
The best way to measure turbidity is with a turbidity tube or Secchi disc, however for more correct measurements, a turbidity meter is beneficial.
Chlorophyll fluorescence evaluation
When water our bodies become eutrophic, oxygen ranges are depleted and nitrogen and phosphorus levels improve, making a poisonous environment for plants and animals. Measuring algal growth and water high quality might help scale back water air pollution.
Chlorophyll fluorescence is measured with a chlorophyll sensor, which data the proportion of moist chemistry and active chlorophyll.
CDOM/FDOM monitoring
CDOM (colored dissolved organic matter) is of course present in water our bodies. UV mild is absorbed by the organic matter and breaks right down to launch the natural contaminant tannin, which makes the water cloudy. Tannins are related to reducing the pH and depleting the oxygen content of the water. When CDOM fluoresces, it’s known as fluorescent dissolved natural matter (FDOM).
Photoelectric sensors are used to measure CDOM/FDOM. they measure the provision of sunshine and the focus of dissolved natural matter (DOM).
Summarizing answer of water air pollution
Water air pollution is an extremely important drawback we are at present dealing with, which is why solutions should be developed to protect the aquatic setting, human well being, and other animals (and plants) that rely upon water techniques.
Testing completely different water parameters will decide water high quality in order that water pollution could be recognized.
If you need to more data on what water quality testing equipment we offer, please be at liberty to contact Apure. We sit up for answering any questions you may have..