Sewage Wastewater Treatment-Gray Water Treatment - Term Paper Example

Sewage Wastewater Treatment-Gray Water Treatment Water is the source of every form of life since without water; life cannot be bearable towards human, plants, animals and everything on earth that really needs the presence of water. Sewage originates from institutional, industries, camping centers, shopping centers, hotels, residential establishments (Oke 78). These include waste from showers, toilets, kitchens, sinks, baths, and from another forms of organic disposals. The sewage is separated into black water and gray water, whereby gray water can be used in watering the plants and the same water is recycled to be used for flushing toilets. Gray water is potentially a source of water which is collected from bathing, dish washer, laundry, showers, sinks (which has not used for disposal of hazardous or toxic materials like chemicals), kitchen sinks (water which has not used food preparation or disposal), clothes washing machines and does not include water form toilets. Gray water is considered easier to treat and recycle than the so called black water because of the low levels of contaminants ( Dandigi 78). It used widely because it some benefits which are; reducing household bills since it reduce the need of fresh water and thereby contributing a lot to community benefit because it extremely reduces the high demands of the public water supply. It also reduces the amount of the wastewater, which is entering the sewer, and this can be beneficial to both households and the community at large. There is another kind of wastewater known as black water, which is the water, used in the transportation of human waste since it is the combination of water and waste from toilets (Thawale 54). On the other hand, gray wastewater is used to the land application areas such as; sub-surfaced irrigation, absorption trenches; dripper under mulch or spray irrigation; evapotranspiration beds and if defected it can be easily applied to the surfaces of the ground. It is also used for irrigation, evapotranspiration beds, for gardening, for compositing, for landscaping at single-family residence, around the foundation of a new house to minimize soil movement or in soil cracking (Patnaik 52). This water is beneficial since it can be used to irrigate the gardens in the times of drought water restrictions, can also reduce the amount of pollution which is going into human water ways which is used for domestic use for example for drinking and in another away can help to save money which can be used in building the strong infrastructure in the provision of water and the treatment of the wastewater. Gray water sometimes is not advisable for use when growing vegetables which are meant for human use because it is not good towards human health; it does not have wet soil, does not have ponds on the surface and has limited access since it is used by residents and some pets. This type of water may be chemically polluted by the dissolved salts for example sodium, phosphates and chloride or by the organic chemicals such as soaps and detergents which in one way or the other might provide food for microorganisms and the plant growth. This water has extremely large levels of detergents which actually contains high levels of phosphorus, boron or sodium and hence should be avoided since can terminate with humans life and health. The water can also be polluted physically by dirt particles sand, lint and food. This water is not safe for drinking because since it might contain some organic solids. Some of the water can be applied directly to the garden or n the container fields which will therefore receive another treatment from the soil in its life and the plants roots. All natural enzymes break down so fast and liquefy starches, proteins, carbohydrates, papers, and vegetable oil and fats. By this way, there is combination of waste digesting activity of bacteria naturally and the free enzyme which keeps the system, leach fields which drains some lines free for the process of organic building up ( Thawale 63). Grey water may contain some nutrients, pathogens, which is some discharged warm whereby in this state it is extremely important to first store before it is used either in the irrigation fields. On the same, rain water is considered clean since it has not been polluted with of the non degradable chemicals for example soaps which is a non natural soap indeed. Grey water can be purified under several steps where potable water is needed which will make it good for drinking, and to perform other duties like in domestic for washing, and for taking shower. Grey water is highly considered for irrigation because it breaks down extremely faster and contains phosphorus and nitrogen which are in extremely low levels ( Thawale 48). In the primary treatment, large solids are removed by using screens, and tanks to settle them while in the secondary treatment; the treatment prevents pollution from the degrading organic matter before the water is released to the environment for use. Generally, an activated sludge plant comprises a number of mechanisms and processes that where oxygen is dissolved in the promotion of biological growth that really removes materials that are organic. This process helps in the conversion of ammonia into nitrates and nitrates to nitrogen gas. In the aerated basin system, the aerators are based under two functions where; they transfer air rich in oxygen that supports biological oxidation reactions, and by providing the rate of mixing required for dispensing oxygen that is used for contacting the reactants (Juwarkar 52). Phosphorus can be removed from the wastewaters that have already been discharged in order to receive water that is eutrophic or rich in nutrients. The biggest aim of disinfection is to substantially reduce microorganisms in the wastewater, which is to be discharged into the environment for use. Its effectiveness of disinfection will automatically depend on the level of quality of the treated water, the dosage of the disinfectant, the type of the disinfection, and its variable measures to the environment (Rawitz 63). Gray wastewater should be highly managed domestically in order to protect the public health and the environment from risks and in this way there will be hope to get to the future. Gray water having pathogens organisms and chemical pollutants it is necessary that the reuse practices adequately protect the health of the pubic to be consistent and go with the principles of ecological development sustainably since it does not decrease the local amenity to the community. Gray water follows a series of processes that this water undertakes from its generation that is the household to its final stage of disposal (Thawale 90). There are several alternatives for treatment of the gray wastewater. A septic tank should be build 3.25 feet, from the building, 10ft or 3 metres form any boundary property, 26 feet or 8 metres from any near well, 50 feet or 15 meters form any water course in this without the including the ditch, 26 feet or 8 metres form any embankment or a cut, 10 feet or 3 metres form any swimming pool around, and also 10 feet or 3 metres from a water holding tank around or in this case any cistern. After the water is collected through a sanitary drainage system, it is discharged in a septic tank, which acts as the primary step. In the septic tank, there are two chambers: the sedimentation chamber and the control chamber (Oke). In this chamber, it is where all the organic solids, flotation of greases and oils, and the aerobic breakdown of all the pollutants. The tank is not fitted with filter thus improving the quality of the affluent. Then this water can also be treated in the secondary level or can directly be applied to the land area for use. In the secondary level, the affluent should not contain a lot of the solids. The aerated wastewater treatment system in this stage acts as the secondary treatment because this is where reeds beds are and the sand filtration is done ( Rawitz 45). The rapid and intermittent discharge of the liquid provides a more even distribution of the wastewater effluent throughout the treatment area, provides an important rest period between discharges to allow the treatment area to aerate, and also provides the protection against freezing. The wastewater after it completes its period in the septic tank it comes to its disposal to the fields through two the trench type. The trench should have a width of 60 centimetres to around one metre. The exaction is then filled with graded stones to a level 30 centimetres, and a perforated pipe, which is laid down in the trenches to cover 10 to 15 centimetres of the graded stone (Rawitz 93). This appears as the final step, which is extremely important because it prevents the saturation of the field by surface water and enhances evapotranspiration of the wastewater effluent. In the tertiary level wastewater is improved to quality water than the one obtained in the secondary level. Water treated with chemical and physical agents to remove the high level of contaminants or in another way, any undesirable mass if contained in the wastewater. Smaller compounds are therefore absorbed on the adsorbents such as the activated charcoal, which is therefore separated out from the water (Jayakumar 43). In this way the carbon presence in the water, helps in removing the residual of the toxic substances in the water. Another method of treating the Gray wastewater is by the use of the cesspools. A cesspool is simply a pit into which this water is emptied. It is like a pit privy, since it designed to function in the same way as the water carriage system. Liquids leach into the soil and therefore solids remain in the ground since this is where they decompose from (Thawale 60). On the same, household wastewater contains a lot of grease, oil, soaps, and other soluble substances, which are deposited on the walls of the cesspool thereby, impending the leaching process. Since there is no provision of the surface, distribution of the fluid effluent, cesspool thereby overflows, discharging onto the surfaces of the ground. Then the cleaning process is undertaken frequently ( Patnaik 52). There is another treatment of the water by the use of the stabilization ponds where this is mostly referred to as the oxidation ponds or lagoons, for they are shallow basins where the use of the aerobic and anaerobic degradation of water. Photosynthesis of the algae is presence in these ponds as this is the element in the ecology of aerobic stabilization. The population of the bacteria supplies carbon dioxide for the algal growth, which later in turn in the supply of oxygen to the wastewater, which therefore help in the maintaining the aerobic process balance. Bacteria in this stage metabolizes the water organics in the water( Yekutiel 59). Chlorination is the other method normally applied in the water treatment. It is mostly used because of the two reasons such as prechlorination which help in the control of hydrogen sulfide, and also help in the destruction of pathogenic bacteria and some other undesirable biological life in the effluent. Its highly used because it is an active oxidizing agent since it has the ability to breakdown the hydrogen sulfide ( Juwarkar 73). This therefore help to prevent corrosion by reducing the potential of the hydrogen sulfide to mix with water where is finally forms sulfuric acid which reduces the odor in the water and therefore making it harmless for use in the showers. Works Cited Thawale P R, Juwarkar A S K. 2006. Resource conservation through land treatment of municipal wastewater. Current Science 90: 704-11. Juwarkar AS, Oke B, Juwarkar A and Patnaik SM. 1995. Domestic wastewater treatment through constructed wetland in India. Water Science and Technology 32: 291-294. Jayakumar KV and Dandigi MN. 2002. A cost effective environmentally friendly treatment of Municipal wastewater using contructed wetlands for developing countries In: Proceedings of the 9th International Conference on Urban Drainage, Portland, Oregon, USA. CPCB. 2005b. Performance status of common effluent treatment plants in India. Central Pollution Control Board, India. CPCB (1999). Status of water supply and Wastewater Collection Treatment & Disposal in Class I Cities-1999, Control of Urban Pollution Series:CUPS/44/1999-2000. Shuval HI, Adin A, Fattal B, Rawitz E, Yekutiel P. 1986. Wastewater Irrigation in Developing Countries: Health effects and Technical Solutions. Technical Paper No. 51. World Bank, Washington DC. CPCB (1999). Status of water supply and Wastewater Collection Treatment & Disposal in Class I Cities-1999, Control of Urban Pollution Series:CUPS/44/1999-2000. Read More