Wastewater Management Essay Example for Free

Wastewater Management Essay In this age of rising costs and depletion of natural resources due to over use by the ever growing population on our planet, it is absolutely essential that we find ways to recycle and conserve wherever possible. One way of doing this is by managing wastewater. The first step in the process replicates what occurs in nature; the only difference is that it is faster. In this initial step, called primary treatment, water is collected in huge tanks and the solid particles are allowed to settle by force of gravity while the remaining mixture is allowed to run off. This process removes about 60 percent of the suspended particles and is only suitable for irrigation of trees or other non consumable crops in remote areas. The secondary treatment is significantly different from the primary in that it involves the biological removal of the organic materials contained in the wastewater. The most common form is called activated sludge method, where the wastewater is placed in tanks which are aerated with oxygen to encourage the growth of microbes found in the waste. The microbes eat the organic matter and the solids are allowed to settle to the bottom. Trickling method is another option in the secondary treatment method. In this process tanks of coarse material are filled with rocks three to ten feet in depth. The rocks are used as surface area on which bacteria called biomass is allowed to grow. Next, a long arm-like distributor sprays the waste water in the air over the biomass, which feeds on the organic waste and allows the remaining liquid to trickle through the rocks. Here water is collected and then sedimentation is allowed to take place. The final method is known as Lagoons. In this method large ponds are used. Algae grows in the ponds and with the use of sunlight produces oxygen. The oxygen then is used by the microbes in wastewater to breakdown the organic material and the solids then settle at the bottom of the pond. After applying the primary and secondary methods the water then is treated with chlorine or other disinfectants. The tertiary treatment goes beyond what is done in the secondary treatment and can involve chemical, physical or biological processes to further remove contaminants, Tertiary processes include filtration, lagooning, nutrient removal and disinfection. Filtration is a common tertiary treatment method. Water is allowed to pass through sand or activated carbon, which allows the particles in water to stick to the filer material used and water to pass through. In some cases the excessive levels of nitrogen and phosphorous must be removed before releasing the water to the environment. If water is released into the environment without removal of these compounds, they can cause over growth of algae and other water plants which in turn can throw the ecosystem out of balance. Some wastewater treatment plants use one tertiary method others a combination of methods. There are many uses of reclaimed water, for example it can be used for irrigation, power generation, decorative fountains, fire control, aquifer recharge, cooling or other industrial processes. Reclaimed water contains nutrients such as nitrogen, phosphorus and oxygen which help fertilize plants. The use of reclaimed water reduces pollution in areas which are sensitive. It cannot be used in swimming pools, or other places where it comes in contact with the body, cooking, drinking, or irrigation of herbs and vegetables. Recent studies show there may be a possible public health effect when using reclaimed water. It has been known for some time that treated wastewater effluent, or reclaimed water, contains pathogens that could be transferred to people through contact and some parasites are not killed by chlorination A water treatment plant in Lake Tahoe, California has been producing drinking quality water from wastewater and astronauts reclaim all their wastewater and use it for drinking. Using wastewater to recharge the water basin and using that for drinking is not an issue provided WHO guidelines for the quality of drinking water are maintained. This means that tertiary wastewater treatments will have to be used before the wastewater can be used to recharge the basin. Since this process is more expensive than secondary treatments, it may not be feasible in the long run.Using secondary wastewater treatments to recharge basins and using that for drinking poses health issues and is not advisable. REFENCES Primary Treatment. (2010). In Encyclop? dia Britannica. Retrieved May 24, 2010, from Encyclop? dia Britannica Online: http://www. britannica. com/EBchecked/topic/476238/primary-treatment An Introduction and Comparison of Primary, Secondary, and Tertiary Wastewater Treatment Methods. (2003-2010). Conjecture Corporation. Retrieved May 24, 2010, from http://www. brighthub. com/environment/science-environmental/articles/68537. aspx Using Wastewater as a resource. By Mark Shwartz. Woods Institute for the Environment Stanford University. Retrieved May 24, 2010 from http://woods. stanford. edu/cgi-bin/index. php. Asano T, Wassermann KL (1980). Groundwater recharge operations in California. Journal of the American Water Works Association, 72(7):380–385. Cotruvo JA (1988). Drinking water standards and risk assessment. Regulatory Toxicology and Pharmacology, 8:288–299.