Detergents and their negative impacts on waterJanuary 17, 2008
Detergents- not so clean for water
They wash white and they wash whitest. Two spoons will do for some and just one for others. They come as powder and they come as bars. Some are meant for hand wash and some for washing machines. They are now nuanced enough to address top loading washing machines and frontloading ones separately. Welcome to the world of detergents and clean clothes India. The ubiquitous soap is now quickly being replaced by detergents for washing clothes as well as for washing dishes. In India the consumption is at 2.7 kg. per person per annum according to one source and therefore over 2.70 million tones of detergents are sold. This market is growing at nearly 9% annually. Comparisons are made with the USA with 10 kg. per person per annum.
As they clean clothes quicker and whiter, detergents have to perform certain functions. Firstly they have to soften water. In India much of the water used from the ground can be hard. The removal of calcium and magnesium salts which generally because the hardness by precipitating them is part of the detergent action. The second is to remove dirt. This is done by increasing the alkalinity of water to dislodge acidic soil. Then the dirt is removed and not allowed to lodge back again by keeping it suspended in the water till the water itself is removed.
In the case of detergents used for utensils, the grease cutting and removal is a key action. This needs phosphorous in the detergent to do the job.
This is all good for the clothes to look clean or the utensils to gleam but the problem is with the water that comes after the wash. Whether it is from a washing machine or from a normal hand wash this wash water has a relatively high level of phosphates. When these phosphates end up in surface water bodies they cause a phenomenon called eutrophication. Due to the phosphate present, the water is nutrient rich. The nutrient rich water is good food for algae to grow and bloom. When these algae die they settle down at the bottom of the river or lake. The micro organisms which feed on the algae demand oxygen from the water for survive. Slowly the water loses its oxygen and fish and other organisms find it difficult to survive in waters without oxygen and they die. Eventually the water itself ‘dies’ in that it is unable to support living organisms.
While there do not seem to be any detailed studies of the problem in India, these impacts have been well documented in Canada and the USA. In Bangalore a sewage channel started foaming and even now when one sees the Vrishbhavati flow on Mysore road flying foam is not an unusual phenomena. Is this due to detergents? Most likely so.
Lessons: There is complete lack of awareness of the impacts that detergents cause on the environment. With a fast going urban consumer market the consumption of detergents will only increase. The detergent industry has to be regulated and standards for the reduction of phosphates brought in so that in a specified time line they are brought down to a minimum or eliminated altogether. Though the Ecomark label was introduced for detergents with no phosphates in them none in India claim this label.
The sewerage systems in India are abysmal and the treatment of collected sewage is also pathetic. More investments will need to go in to the sector. Collection system for waste water needs to improve so that no waste water is allowed uncollected. Treatment systems have to cater to both nutrients, nitrate and phosphate so that these are used as soil fertilizers rather than allowed to enter water bodies, be they rivers or lakes.
What we put into our waters is crucial to understand and manage. It is better for us to pay to keep the water clean than to first pollute the water and then try to clean it later. The ecological cleaning of waters takes a long time and is in general costlier. Prevention as always is better than cure.
Finally we must need to make the right choice of the most eco-friendly detergent and use them sparingly and judiciously realizing fully the negative impact they can have on the environment. Water wisdom is in knowing what we put into our waters and what we can do to minimize its negative impact and then acting on it