What is Reverse Osmosis

reverse-osmosisIf you put a spoonful of honey into a glass of pure water, what will happen? Of course, you cannot separate them anymore and you get a glass of a mixture of honey and water. This phenomenon is called diffusion. There is something different between diffusion and osmosis. Diffusion is the movement of atoms or molecules from a region where the concentration is higher to a region where the concentration is lower. Osmosis does the same and it is one special type of diffusion. In osmosis, molecules that will move are water and there is a semipermeable membrane to separate two different kinds of concentration of water. The membrane only allows water to pass through. Therefore, the water will pass through it from one side of higher concentration to another side of lower concentration. Other larger molecules (like urea, bacteria, glucose) or ions (like Na+, Ca2+, Cl-) cannot pass through the membrane.

Diffusion, as well as osmosis are thermodynamically favorable and don’t stop unless equilibrium is reached. Osmosis is very special, because it can be slowed, fastened, stopped. Plus, there is enough pressure applied to one side of higher concentration. Therefore, water molecules will pass through the membrane from the lower concentration side to the higher concentration side.

Reverse osmosis cannot occur naturally, because this goes against nature. The applied pressure makes water molecules go through the membrane from the lower concentration side to higher concentration side, which is contrary to the concentration gradient. This method is perfect for using for purifying water. If there is a semipermeable membrane between two kinds of concentration water. One side is fresh water and another side is contaminated water. Naturally, the fresh water will pass through the membrane to dilute the contained water. However, we can apply enough pressure on the side of contaminated water and make the diffusion process reversed. Water molecules move from the side of contaminated water to the side of fresh water. Fresh water becomes more and more. This process can allow us to purify our water, because it can separate pollutants from water.

On the market, more and more water filtration method to filter water. It even can be used to desalinate seawater. Compared to other types of water filtration methods, reverse osmosis is regarded on of the most effective and economical ways to purify water.

Pros and cons compared with other types of filtration methods:


  • More effective
  • Can remove more types of contaminants
  • Can offer plenty of filtered water in a short time


  • Costly – the initial cost is a little high and its filters need to be replaced on a regular basis.

7 Power Drill Safety Tips When Using Your Drill

When do you use a drill? It’s mainly because it can provide you more power when drilling. Therefore, it requires your proper operating. It’s very important to carefully use a powerful drill. Here are some power drill safety tips we must follow for our safety. Although a drill is a small appliance, but it may hurt you if you don’t use it properly.

Before you begin to use the drill, first read the manual carefully. And this can tell you how to use the drill properly. In the following, we will give 7 safety tips when using a drill.

1. Choose the right drill

It is known that high voltage means more power. However, different jobs may need different RPM. You must choose the right drill to do the right job. If you have low voltage drill to drill some holes in the wall, it is obviously inappropriate. In the same way, you’d better not use a high voltage just to screw nails.

2. Wear safety goggles and gloves

You’d better wear your safety goggles when do the drilling job, because when drilling tiny fragments may fly all over. To avoid hurting your eyes, wearing your safety goggles is a wise decision. In the meantime, safety gloves can protect your hands from hurting.

3. Properly place the chuck

If you don’t use your drill, make sure to take the chuck key off if the drill has the chuck key. Flying chuck key may cause serious injuries. Before using the drill, make sure the chuck is placed properly. Also it’s very important to use the right drill bit. If you want to change the drill bit, first you should turn off the drill.

4. Be careful about the environment

If you want to use it on the wall or in the floor, make sure there are no live wires. And don’t use the drill in a gaseous explosive and wet environment.Be careful: Sparks from it may cause serious problem.

5. Wear Proper Clothe

When doing drilling job, don’t wear loosing clothe, or the drill may be easily caught in the clothes and cause injury. And avoid putting your hand on the trigger if you don’t use it.

6. Keep hand free

Before starting the drilling job, it’s a good idea to keep your hands free. The drill bit may get clogged or bind in the long time use. Turn off the drill and clean it before the next time use. If the drill you use has the reverse torque option, cleaning is much easier.

7. Charge the batteries properly

If you use a cordless drill (many people use them), the batteries are an essential part of the drill. When you need to charge the batteries, make sure the charger you use come with the batteries. If you use some other charger to charge the batteries, both the charger and batteries have the risk of damage. Different batteries may need different voltage and current to charge. You need to check the charger and drill regularly and repair it if necessary. This ensures the drill lasts for a long time.

Buyers guide to Cordless Drills

If you really need to do some home improvements tasks, choosing the right power tool is very important; no matter you are professionals or DIYers.


The common tool we might use is a drill. On the market, there are two types of drills: Cordless one and corded one. They all have their advantages and drawbacks. But for most people, cordless drills are their best choice.Compared with corded ones, cordless drills don’t have any twisted cables. And they are all lightweight can compact design which make them perfect for tight spaces.


  • More portable and Flexible
  • Without a trailing cord
  • Compact and lightweight Design
  • Perfect for small spaces

Also the cordless drills have their drawbacks. You need to charge the battery. Once the battery is run out, you cannot work. So at least you should buy 2 batteries for longer jobs. Most Cordless drills on the market include 2 batteries.


  • Less Power than a corded one
  • Battery need to be charged regularly

When you decide to buy a cordless drill, some important features are considered.


The voltages are different from 2.4v to 24v. The higher voltage, the more power and better performance, which means you can do your job quickly. If you tend to high speed drills, you may choose a higher voltage one. Normally the charge on higher batteries last the same as the lower ones. But with higher batteries you will get higher power and increased speed.

If you are not a professional or a serious DIYer, a low voltage drill (12v) is enough. 18+v ones are ideal for serious DIYers and professionals, but you may pay more to get such a powerful tool.


Speed is another aspect we must consider. RPM (rotations per minute) can tell you the speed. When you choose a drill, try to choose one with a wide range of speed settings. And this can allow you do a wide range of tasks.

Chuck Size

Chuck sizes have two types: 1/2 inch and 1/3 inch. The chuck size is the maximum size of a hole you can drill. Generally for average DIYers, 1/3 inch is enough. For serious DIYers or professionals, choosing 1/2 inch size is sise.

Hammer Action

If you need to drill concrete, bricks and masonry, you need to buy one with hammer action.

Something to be considered before buying one

There are so many models of cordless drills, but which is the best cordless drill for you? Before buying one, you need to consider the following things:

1. What will you use it for? This determine the voltage you need

2. One or two batteries? Of course, two is perfect. Look for sets included two batteries/

3. Do you need to drill hard masonry? If so, you need to choose one with hammer function.

4. A quick charger is essential for you? If so, you need to choose one which can be charged full around 30 minutes.

The best advice I will give you is to read some consumers reviews before buying it. To do this, you will finally get what you really want. These reviews coming from people who have used it are valuable. There using experience can help us a lot.

DeWalt DCD785C2 20-Volt MAX Lithium-Ion Compact Hammer Drill/Driver Reviews

If you are a plumber, builder, commercial electrician or just a DIYer, having the best power tool is helpful to your job. A lightweight and compact tool will help you do the job easier. Choosing this DeWalt DCD785C2 cordless drill can help you finish the tasks efficiently and avoid accidents.

Many people tend to buy a cordless drill according to its price and their budget. However, the fact is not the truth. They will feel regretted because of having such a drill. When we decide to buy a cordless drill, we need to know which one is the best.

The battery, speed, weight, torque and power of the drill are the key features we need to consider. These features are important to us. This DeWalt DCD785C2 is such one of the best cordless drills. In the next, I will tell you why this model is worth to have.


>>>Click Here to See Pricing, Ratings, and Reviews on Amazon.com

To help you choose the right tool not the wrong one, please read carefully my review of the Dewalt DCD785C2 cordless drill. I will cover the key features of this model: Power, speed, weight, torque and even the battery. If you use it frequently, these features are very important. At last, I have done some research on consumers reviews. These reviews are written by actual users. They are unbiased. They highlight any fault and advantage.

The following is my unbiased reviews of this Dewalt DCD785C2 20-Volt MAX Lithium-Ion Compact Hammer Drill/Driver.

What’s in the box?

  •  The drill/driver and an on-board bit holder
  •  Two Lithium-Ion batteries One 30 Minute Charger, compatible with both 12v and 20v Lithium-Ion Batteries
  •  One belt hook
  •  Strong plastic storage carry case



This model is powered by a 20v max Lithium-ion battery which can provide you with 35% more runtime than other 18v lithium-ion batteries. This battery is not compatible with older Dewalt drills.


The special Dewalt-designed electronics which are built into the switch can provide longer life both for the tool and battery. This is effective to prevent overheating, overloading and deep discharge.

The 30-minute charger can work both with 20v and 12v batteries. If you have a small tool, you can use it to charge it.

Power And Speed

This Dewalt cordless drill has 350w of power. It is ideal for light and medium drilling task. There are two speed settings: high speeds range from 0 to 2000 rpm and low speeds can range from 0 to 600 RPM.


Generally, if the drill has a higher voltage, it may be heavier than others with low voltage. This means the more powerful of the drill, the heavier and bigger it is. However, this Dewalt CD785C2 hammer drill is only 3.5lbs. And the compact design makes it ideal for small spaces.

Other Features

This drill has a moulded handgrip which is helpful for long time use. To make this tool be felt lighter and balanced, the Dewalt has changed the weight allocation. This design is very handy for tight spaces.

Also this model is equipped with LED light, which is above the trigger. This is useful in dim areas.

Where to get this Dewalt DCD785C2?

Although there are many places you can get this model, the best place to buy this model is at Amazon.com because of the best price. At the same time, you can check the consumer reviews before buying it.

>>>Click Here to See Pricing, Ratings, and Reviews on Amazon.com

DEWALT DCD760KL 18v Cordless Drill Reviews

DEWAL-DCD760KL-18v-Cordless-DrillAs a cordless drill manufacturer, the brand Dewalt means more. At least, their drills have never made me feel disappointed. This DEWALT DCD760KL is one of the best cordless drills manufactured by Dewalt. Its reliability and power make me feel good about my drilling job.

This model has enough power to drill through anything I use it to drill. This super guy can easily drill through the knots in the wood.

The chuck size of this model is a 1/2 inch chuck, which is proven to be a godsend to me. It has saved me a lot of time on some of my projects. After using this drill with 1/2 inch chuck, I think I will don’t use other drills with 3/8 inch chuck. Also the compact and lightweight design gives me a good impression.

Generally the batteries for drills tend to be huge size batteries. I found recently there are some smaller lithium batteries. However, I haven’t found that Dewalt offered such kinds of batteries, while other manufactures such as Bocsh and Milwaukee begin to offer many small batteries in their new models. But I recommend choosing this best cordless drill because of its reputation, power and reliabilities.

Even though I prefer a slim battery, I love this model because the packs from Dewalt can be changed between each other. This feature is not widely offered by other companies.

The drill can last for a pretty long time if the battery is fully charged. Also the charging time is very short, about 30 minutes. This feature allows you to prepare your job easily. The old types of nickel batteries are not the same. Before doing drilling job, you need to wait a relatively long time to charge the batteries.


  • A true power tool around the house. This cordless drill can help you handle any drilling task around the house.
  • Chuck is easy to use. Changing the chuck is easy and safe. Once the chuck is placed, it doesn’t slip up any more.
  • Fast batteries charge and a longer battery life. Batteries can be used in other 18v Dewalt models.


  • Batteries are bigger than other drills on the market 

I highly recommend this model. And the average rating of this cordless drill is 4.3 out of 5. There are over 144 consumers’ reviews. Almost most of them think this model is a worthy investment.

>>>Click Here to See Pricing, Ratings, and Reviews on Amazon.com


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