Environmental Engineering Water Treatment Processes †Free Samples

Question: Discuss about the Environmental Engineering Water Treatment Processes. Answer: Introduction Treating water and safely storing it in the home are commonly referred to as ?household water treatment and safe storage or treating water at the ?point of use. Although household water treatment is not new, its recognition as a key strategy for improving public health is just emerging. For centuries, households have used a variety of methods for improving the appearance and taste of drinking-water. Successive generations were taught to boil water, expose it to the sun or store it in metal containers with biocide properties, all in an effort to make it safer to drink. It is recognized that the best way to reduce the risks associated with drinking unsafe water is by using the multi-barrier approach. Each step in this approach, from source protection, through water treatment to safe storage, provides an incremental protection against unsafe drinking-water. The concept of the multi-barrier approach is part of water safety plans, the principles of which can be applied at both community and household levels. Both conventional community and household systems follow the same basic water treatment process: sedimentation, filtration and disinfection (Fig below ). A typical community-level system that relies on surface water, for example, may incorporate source protection (drawing water from a deep inlet away from shore), assisted sedimentation (using coagulants), filtration (rapid sand) and disinfection (with ozone and chlorine to minimize recontamination during distribution). The Role Of Waste Water Treatment And Storage Waste water treatment and storage can help improve water quality at the point of consumption, especially when drinking-water sources are distant, unreliable or unsafe. However, waste water treatment and storage should be viewed primarily as a stopgap measure only; it does not replace the obligation of a service provider to provide access to safe drinking-water. It is intended for people who have no access to improved drinking-water sources, for people with access to improved sources outside of their home or premises (i.e. when contamination can occur during transport and storage), for people with unreliable piped supplies who have to store water to bridge the gaps between deliveries, and for people in emergency situations. Waste water treatment and storage can contribute to global efforts to provide universal access to safe drinking water. In many settings, both rural and urban, populations have access to sufficient quantities of water, but that water is unsafe as a result of microbiological or chemical contamination. This is increasingly true even for piped water. Supplies are rarely provided on a continuous basis, leading to faecal contamination of poorly maintained distribution systems and forcing households to store water in ways that can be easily recontaminated. For those who did not have access to sufficient quantities of water that requires treatment to remove pathogens, Waste water treatment and storage made a direct contribution to the Millennium Development Goal water target. Waste water treatment and storage has the potential to advance several health and development aims. There is evidence that the correct and consistent use of effective waste water treatment and storage among those relying on contaminated water supplies can prevent diarrhoeal diseases, a major killer among young children. Because enteric infection interferes with normal absorption of nutrients, waste water treatment and storage also has the potential for alleviating hunger. In conclusion Implementation experience suggests that waste water treatment and storage: ? dramatically improves microbiological water quality; ? can significantly reduce diarrhea disease if used correctly and consistently by a vulnerable population; ? is highly cost-effective; and ? can be quickly implemented and taken up by vulnerable populations. Waste water treatment and storage can contribute to the Sustainable development goals on water target while advancing other health and development goals. Providing safe, reliable, piped-in water to every household is an essential goal. However, the resources needed to construct, operate and maintain a piped community water supply system are not always available. Waste water treatment and storage can provide the health benefits of safe drinking-water while progress is being made in improving water supply infrastructure. Piped water systems and waste water treatment and storage should not be viewed in competition with one another; rather, they are complementary and both play a role in providing safe water and improving health. Resources should not be diverted from piped systems to support waste water treatment and storage programmers. Results Raw Water valuation Phase Turbidity (Nephelometric turbidity units) UV254_10cm DOC Colour (Pt/Co) Remarks Raw water Trial 2 0.274 8.779 32 Table 1 Turbidity From this initial raw water quality assessment, there is a clear detection of greater turbidity of 2.00 NTU as measured using HACH2100 Turbidimeter, this is an indication that there is a greater availability and presence of very fine clay particles. Hence, this water is not recommended for drinking until its purification takes place, since the proportion for turbidity for conducive water to be taken is supposed to be less than 0.1 Nephelometric turbidity units UV Absorbance (UV254) From this initial raw water quality assessment, there is greater indication that the raw water contains dissolve organic compounds with aromatic structures from natural organic materials, as per the record of 0.274, the water hence in recommendation is not suitable for drinking until the purification procedure takes place. Colour from the record of the initial quality assessment of raw water the water colour is found to be 32 Pt/Co, hence the water is able to absorb the light in the visible spectra range, a clear indication that the water contains dissolved minerals, dyes or humic acid from either plants or animals, water state is not recommended for drinking since recommended drinking water should contain below 3 Pt/Co Dissolved organic Carbon From the record of the initial water assessment quality the DOC recorded is 8.779, this is a clear indication that the water contains more dissolved organic carbon, hence the water is not recommended for drinking Optimum dosage of FeCl3.6H2O FeCl3.6H2O (mg/L) 5.00 10.00 25.00 50.00 Turbidity (NTU) 1.00 1.00 1.00 0.00 Colour (Pt/Co)) 21.00 30.00 0.00 -4.00 DOC 7.471 6.774 3.437 2.777 UV254_10cm 0.27 0.27 0.07 0.0652 Table 2 Turbidity The addition of ferric chloride in dosage on the initial raw water is observed to be reducing the turbidity from the initial 2 NTU to 1 NTU, 1 NTU, 1 NTU, 0 NTU on the dosage of 5.00 milligram per litre, 10.00 milligram per litre, 25.00 milligram per litre, 50.00 milligram per litre respectively of ferric chloride, this is an indication that that at 50 milligrams per litre ferric chloride the water is perfectly having no cloudiness. UV Absorbance (UV254) The addition of ferric chloride in dosage on the initial raw water is observed to be reducing the UV absorbance from initial 0.274 to 0,27, 0.27, 0.07 and 0.0652 on the dosage of 5.00 milligram per litre, 10.00 milligram per litre, 25.00 milligram per litre, 50.00 milligram per litre respectively of ferric chloride, this is an indication that much part of dissolve organic compounds with aromatic structure has reacted with the ferric chloride and have be been removed. Colour The addition of ferric chloride in dosage on the initial raw water is observed to be reducing the colour from initial 32 Pt/Co to 21 Pt/Co, 0 Pt/Co and -4 Pt/Co on the dosage of 5.00 milligram per litre , 10.00 milligram per litre, 25.00 milligram per litre, 50.00 milligram per litre respectively of ferric chloride, this is an indication that much part of dissolved minerals, dyes or humic acid from either plants or animals has been removed from their reaction with ferric chloride dosage, hence the water is perfectly colourless. Dissolved organic Carbon The addition of ferric chloride in dosage on the initial raw water is observed to be reducing the dissolve organic carbon from initial 8.779 to 7.471, 6.774, 3.437 and 2.777 on the dosage of 5.00 milligram per litre, 10.00 milligram per litre, 25.00 milligram per litre, 50.00 milligram per litre respectively of ferric chloride, this is an indication that more dissolve organic carbon have been removed from their reaction with ferric chloride Graphical presentation of impact on ferric chloride on the raw water Cl features for raw H2O Date Time Total chlorine (mg-Cl2/L) Remarks MQ Raw water 5.00 mg/L FeCl3 10.00 mg/L FeCl3 25.00 mg/L FeCl3 50.00 mg/L FeCl3 0.00 2.00 2.00 2.00 2.00 2.00 5 0.84 0.93 1.09 1.44 1.41 10 0.56 0.64 0.89 1.35 1.27 20 0.23 0.62 0.73 1.20 1.18 Table 3 From the table of chlorine decay for raw water and water containing ferric chloride, it observed that decay is decreasing with time in all the cases, but the water containing the dosage of ferric chloride at different amount having greater decay respectively as compared to the raw water. This is a clear indication that the raw water had greater availability of microorganism or pathogens as compared respectively to the water with different dosage of ferric chloride, hence lesser used. THM levels in treated, raw and MQ water Date Trihalomethane Before Cl deterioration trial for 50.00 milligram per litre ferric chloride added sample After Cl deterioration trial for 50.00 milligram per litre ferric chloride added sample 0.00 3.00 Table 4 It is observed that the Trihalomethane after Chlorine decay test for 50.00 milligram per litre ferric chloride is higher as compared to before Conclusion In conclusion, for effective water treatment to be recommended for drinking must be able to contain lesser turbidity, lesser UV absorbance, colorless in color and lesser DOC, and all this can be achive by dosage of ferric chloride in the raw water and injection of chlorine at the end to kill the pathogens, during the process of water treatment