Question

 

ANSWER ALL QUESTIONS.

 

Use the HARVARD METHOD to refer to sources used in the text

 

QUESTION ONE 30 MARKS Describe Waste Water Treatment options.

 

 

QUESTION TWO 30 MARKS Discuss the concept of Operation and Maintenance of Waste Water Treatment

 

 

QUESTION THREE 40 MARKS Discuss the Effects of poor Operation and Maintenance of Waste Water Treatment

 

TOTAL 100 MARKS                                                                                                                                

 

Answer 1

1) Four common ways to treat wastewater include physical water treatment, biological water treatment, chemical treatment, and sludge treatment. Let us learn about these processes in detail.

Physical Water Treatment
In this stage, physical methods are used for cleaning the wastewater. Processes like screening, sedimentation and skimming are used to remove the solids. No chemicals are involved in this process.

One of the main techniques of physical wastewater treatment includes sedimentation, which is a process of suspending the insoluble/heavy particles from the wastewater. Once the insoluble material settles down at the bottom, you can separate the pure water.

Another effective physical water treatment technique includes aeration. This process consists of circulating air through the water to provide oxygen to it. Filtration, the third method, is used for filtering out all the contaminants. You can use special kind of filters to pass the wastewater and separate the contaminants and insoluble particles present in it. The sand filter is the most commonly used filter. The grease found on the surface of some wastewater can also be removed easily through this method.

Biological Water Treatment
This uses various biological processes to break down the organic matter present in wastewater, such as soap, human waste, oils and food. Microorganisms metabolize organic matter in the wastewater in biological treatment. It can be divided into three categories:

• Aerobic processes: Bacteria decomposes the organic matter and converts it into carbon dioxide that can be used by plants. Oxygen is used in this process.
• Anaerobic processes: Here, fermentation is used for fermenting the waste at a specific temperature. Oxygen is not used in anaerobic process.
• Composting: A type of aerobic process where wastewater is treated by mixing it with sawdust or other carbon sources.

Secondary treatment removes most of the solids present in wastewater, however, some dissolved nutrients such as nitrogen and phosphorous may remain.

Chemical Water Treatment
As the name suggests, this treatment involves the use of chemicals in water. Chlorine, an oxidizing chemical, is commonly used to kill bacteria which decomposes water by adding contaminants to it. Another oxidizing agent used for purifying the wastewater is ozone. Neutralization is a technique where an acid or base is added to bring the water to its natural pH of 7. Chemicals prevent the bacteria from reproducing in water, thus making the water pure.

Sludge Treatment
This is a solid-liquid separation process where the least possible residual moisture is required in the solid phase and the lowest possible solid particle residues are required in the separated liquid phase.

An example of this includes dewatering of sludge from industrial wastewater or sewage plant where the residual moisture in dewatered solids determines the disposal costs and the centrate quality determines the pollution load returned back to the treatment facility. You need to minimize both.

A solid-liquid separation device such as a centrifuge is used for removing the solids from the wastewater.

Wastewater has a lot of impact on the natural world and it is important to treat it effectively. By treating wastewater, you don't just save the creatures thriving on it, but also protect the planet as a whole.

2) Operations and Maintenance are the decisions and actions regarding the control and upkeep of property and equipment. Operations are the activities to make sure the plant produces the desired quality and quantity of treated water and meets the current legislation, while maintenance are the activities to make sure the plant equipment continues to work efficiently to achieve the operational objectives.

Water and wastewater treatment plants are no longer traditional plants; monitoring is not just taste, odor, iron and manganese; water treatment facilities are more complex now a days, new technologies have emerged, raw water is more difficult to treat, the treatment requires more innovative solutions, there is an increasing demand for services, diminishing resources, rising service expectations of customers and increasingly stringent regulatory requirements. This all leads to analyzing and enhancing the way we look at operation and maintenance in the water and wastewater industry and the treatment facilities that should be developed and expanded to accommodate these dramatic changes.

Another reason is the growing trend in outsourcing the operation and maintenance of water and wastewater treatment plants.There are many books and articles talking about operation and maintenance and some are talking about the water treatment plant operation, but it seems that we are missing that comprehensive approach between them to successful operation and maintenance. This article will provide a comprehensive approach on the ‘O’ and the ‘M’ in the operation and maintenance of water and wastewater treatment plants.

The operation and maintenance of water and wastewater plants has been generally been broken up in to five main critical elements; operation, maintenance, engineering, training and administration

The new approach is broken down to eight critical elements; WH&S plan, Scope of service, Operation plan, asset and maintenance plan, people, analytical protocols, communication and reporting, and administration.

The main objective of all elements is to support the effectiveness of the fundamental core element; operation and maintenance.All of these elements should be well defined before starting an implementation process and analyze should be undertaken as to how these elements are linked to form a sound program structure. However the link is very obvious – O&M work together.

3) Poor operation and maintenance of wastewater and sewage treatment infrastructure is a cause for concern. Many water quality studies revealed that this problem contributes to the pollution of water resources upon which most rural communities depend for all their domestic and other purposes. Pollution as a result of poor wastewater and sewage treatment infrastructure has a direct impact on human health and the environment.

poor operation and maintenance of wastewater and sewage treatment plants have a great impact on both the environment and human health. Ignorance to properly maintain wastewater and sewage treatment infrastructure has led to effluents with various types of pollutants being deposited into water resources.