The paper “ Methods to Achieve Waste Minimization in Paper and Pulp Manufacturing, Estimation of Moisture Content, Seawater Desalination Process” is a perfect example of an assignment on technology. From the table, the SS value of stream #4 and #5 is very high as compared to other streams. This means it is highly concentrated. Therefore, an effective scheme will involve separating #4 and #5 followed by anaerobic digestion treatment. Stream #3 has more water content. This water can be recycled in order to minimize wastes. Stream #6 and #7 have got low SS values. This shows that it is lowly concentrated.
They contain a lot of water or are dissolved in water. Some of the components in #6 and #7 should first be separated from any water content before further processing. Streams #1, 2, and 7 can be let to settle in order to segregate them from other wastes, and then subject them to further treatment. The flow and the BOD concentration of the combined stream of #4 and #5.The BOD concentration of combined #4 and #5 stream is given by: =The Flow of the combined #4 and #5 stream is given by = 0.3991 L/min Question 2The three methods used to achieve waste minimization in paper and pulp manufacturing processes. By-product recoveryIn paper and pulp manufacturing process, by-products can be recovered through two main methods.
This includes recovery from black liquor and recovery from effluents. Black liquor gets concentrated in many stages through the process of evaporation. It is heated using steam until it remains with about 66% solids and then the black liquor obtained is burnt within the recovery boiler and different salts are produced in the process.
Such salts include sodium sulfate, sodium carbonate, and sodium sulfide. Process chemical changeBleaching in the pulping mills leads to the production of COD by almost half. Therefore, in order to reduce the COD in the pulping mills, hydrogen peroxide or chlorine oxide can be used instead of ozone or chlorine bleaching. Hydrogen peroxide is very strong in both oxidizing and reducing. It does not have the environmental impacts associated with chlorine and that is why the chemical change to use hydrogen peroxide is preferable. It can reduce the yellowing of pulp. Wastewater recyclingThe different chemicals used in the paper industry make the paper to be colored.
A lot of water and some additions are used in order to decolor the paper. Wastewater is produced depending on the bleaching agents used. The wastewater results from the paper machines and processes. It is treated and put back into use. Some of the methods of water treatment include a reverse osmosis process. Question 3Human Barriers of Waste MinimizationPeople’ s attitudesPeople normally tend to waste rather than to save. Some do not know how to segregate the wastes.
The negative attitude of the workers may also lead to insubordination towards waste minimization. Lack of resourcesA lot of knowledge, people, or money are needed in order to carry out effective waste minimization. Some recycling processes need technological know-how. For instance, besides having the equipment, some knowledge is required in the operation of the reverse osmosis equipment. Money may also pose challenges because some equipment is expensive. Lack of environmental concern and awarenessThis is a common barrier since most people do not have sufficient information about the need to preserve the environment.
Awareness of the need to preserve water resources and natural resources, such as trees, should be used in the most economical ways to avoid waste. Trees play a crucial role in purifying the environment.
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