1. For avoiding blockage of sewer lines, they must be designed taking consideration of slope. Also as mentioned by VIT, what material is causing blockage to sewer is also important.
2. The foul smell in sewer is mainly due to stagnant conditions of sewage which leads to anaerobic decomposition of organic matter. As mentioned earlier, slope must be provided to avoid blockage as well as stagnant conditions of sewage in sewer lines. You must remember, sewer lines are provided to carry sewage from the sources & not for the decomposition or treatment of various pollutants of sewage.
3. You need to be more precise for answer of 3rd question. Biological degradation of plastic waste is quite complicated process.
Add more details to your questions, so that they can be answered accordingly.
Hi. Dr. D C.. Pl issue your questions re done. However for SLWM meaning Solid Liquid Waste Managemnt and apt remediation can be done using bio-means. Even air pollution processed by one site greens etc.. w wshs Prof Ajit Seshadri. Vels University. Chennai .
If it is a solid waste directly go for biological pretreatment where microorganism will degrade the solid by utilizing the carbon source. Even it can be utilized for biomass to ethanol production. If it is liquid then go for activated sludge aeration system
I agree the question is unclear. However, in general, waste is constantly being treated in the environment by physical, chemical and biological means, both aerobic and anaerobic. This is true on land and in water. Man-made systems often are designed to try to mimic such natural processes. This is true in a wastewater treatment plant designed to utilize the activated sludge process whereby a variety of microorganisms break down biosolid waste into carbon dioxide and water, resulting in a treated waste effluent (water) and usually a sludge bi-product. This sludge bi-product is then usually also treated which can be by say aerobic or anaerobic digestion or in other ways such as composting, all of which rely on microorganisms to provide the treatment. Organic solid waste (garbage, yard waste, etc.) can also be treated in a similar way by composting. All of this is just touching the surface as to the many ways biological treatment reduces waste.