Palm oil mills with wet milling process are accounted for major production of palm oil in Malaysia, Indonesia and Thailand. Besides the main product “crude palm oil”, the mills generate many by-products and liquid wastes which may have a significant impact on the environment if they are not dealt with properly.
Palm oil mill effluent (POME) is the mixture of high polluted effluent (from sterilizer and oil room) and low polluted effluent (steam condensate, cooling water, boiler discharge and sanitary effluent).
The effluent characteristics indicates that the COD,BOD and TOC levels are quite high with acidic pH due to free fatty acids.
The primary treatment followed by Anaerobic Treatment reduces COD levels in a range of 3000-6000ppm, which is then treat by Aerobic Process using Aeration Pond/ Extended Aeration.
These programmes reduces BOD levels in a range of 200-300ppm much above the discharge limits.
The poor efficiency is mainly because of:
• Low levels of Dissolve Oxygen
• Limited activity of Bacteria Biomass
The DO levels in both aeration pond or extended aeration systems are always limited as compared to activated sludge treatment.
Lower DO levels also encourage floating sludge and heavy filamentous growth.
Industrial Pollution
With the coming of the Industrial Revolution, humans were able to advance further into the 21st century. Technology developed rapidly, science became advanced and the manufacturing age came into view. With all of these came one more effect, industrial pollution. Early industries were small factories that produced smoke as the main pollutant. However, since the number of factories were limited and worked only a certain number of hours a day, the levels of pollution did not grow significantly. But when these factories became full scale industries and manufacturing units, the issue of industrial pollution started to take on more importance.
Any form of pollution that can trace its immediate source to industrial practices is known as industrial pollution. Most of the pollution on the planet can be traced back to industries of some kind. In fact, the issue of industrial pollution has taken on grave importance for agencies trying to fight against environmental degradation. Nations facing sudden and rapid growth of such industries are finding it to be a serious problem which has to be brought under control immediately.
Industrial pollution takes on many faces. It contaminates many sources of drinking water, released unwanted toxins into the air and reduces the quality of soil all over the world. Major environmental disasters have been caused due to industrial mishaps, which have yet to be brought under control. There are many different factors that comprise of the issue of industrial pollution.
Causes of Industrial Pollution
1. Lack of Policies to Control Pollution: Lack of effective policies and poor enforcement drive allowed many industries to bypass laws made by pollution control board which resulted in mass scale pollution that effected lives of many people.
2. Unplanned Industrial Growth: In most industrial townships, unplanned growth took place wherein those companies flouted rules and norms and polluted the environment with both air and water pollution.
3. Use of Outdated Technologies: Most industries still rely on old technologies to produce products that generate large amount of waste. To avoid high cost and expenditure, many companies still make use of traditional technologies to produce high end products.
4. Presence of Large Number of Small Scale Industries: Many small scale industries and factories that don’t have enough capital and rely on government grants to run their day-to-day business often escape environment regulations and release large amount of toxic gases in the atmosphere.
5. Inefficient Waste Disposal: Water pollution and soil pollution are often caused directly due to inefficiency in disposal of waste. Long term exposure causes chronic health problems, making the issue of industrial pollution into a severe one. It also lowers the air quality in surrounding areas, causing many respiratory disorders.
6. Leaching of Resources From Our Natural World: Industries do require large amount of raw material to make them into finished products. This requires extraction of minerals from beneath the earth. It destroys the land used for mining and drilling, by removing all resources and leaving it to waste away, or through leaks and accidents that cause oil spills in both the land and the sea.
Effects of Industrial Pollution
1. Water Pollution: The effects of industrial pollution are far reaching and liable to affect the eco-system for many years to come. Most industries require large amounts of water for their work. When involved in a series of processes, the water comes into contact with heavy metals, harmful chemicals, radioactive waste and even organic sludge.
These are either dumped into open oceans or rivers, or the water that has been polluted by them is released into the ground. As a result, many of our water sources have trace amounts of industrial waste in them and it seriously impacts the health of our eco-system. This water is used for irrigation, washing our food at home and sometimes recycled into drinking water.
Water pollution has already rendered many ground water resources useless for humans and wildlife. It can at best be recycled for further usage in industries, which costs tremendous amounts of money.
2. Soil Pollution: Soil pollution is creating problems in agriculture and destroying local vegetation. It also causes chronic health issues for the people that come in contact with such soil on a daily basis.
3. Air Pollution: Air pollution has led to a steep increase in various illnesses and it continues to affect us on a daily basis. With so many small, mid and large scale industries coming up, air pollution has taken toll on the health of people.
4. Wildlife Extinction: By and large, the issue of industrial pollution shows us that it causes natural rhythms and patterns to fail, meaning that the wildlife is affected in a severe manner. Habitats are being lost, species are becoming extinct and it is harder for the environment to recover from each natural disaster. Major industrial accidents like oil spills, fires, leak of radioactive material and damage to property are harder to clean-up, since they have a higher impact in a shorter span of time.
5. Global Warming: With the rise in industrial pollution, global warming has been increasing at a steady pace. Smoke and greenhouse gases are released by the factories into the air, which causes an increase in the greenhouse effect and increase in global warming. Melting of glaciers, extinction of polar beers, floods, tsunamis, hurricanes are few of the effects of global warming.
The issue of industrial pollution concerns every nation on the planet. As a result, many steps have been taken to seek permanent solutions to the problem. Better technology is being developed for disposal of waste and recycling as much polluted water in the industries as possible. Organic methods are being employed to clean the water and soil, such as using microbes that naturally use heavy metals and waste as feed. Policies are being pushed into place to prevent further misuse of land. However, industrial pollution is still rampant and will take many years to be brought under control.
Article by Conserve Energy Future
Wastewater treatment is closely related to the standards and/or expectations set for the effluent quality. Wastewater treatment processes are designed to achieve improvements in the quality of the wastewater. The various treatment processes may reduce:
1. Suspended solids (physical particles that can clog rivers or channels as they settle under gravity)
2. Biodegradable organics (e.g. BOD) which can serve as “food” for microorganisms in the receiving body. Microorganisms combine this matter with oxygen from the water to yield the energy they need to thrive and multiply; unfortunately, this oxygen is also needed by fish and other organisms in the river. Heavy organic pollution can lead to “dead zones” where no fish can be found; sudden releases of heavy organic loads can lead to dramatic “fishkills”.
3. Pathogenic bacteria and other disease causing organisms These are most relevant where the receiving water is used for drinking, or where people would otherwise be in close contact with it; and
4. Nutrients, including nitrates and phosphates. These nutrients can lead to high concentrations of unwanted algae, which can themselves become heavy loads of biodegradable organic load Treatment processes may also neutralize or removing industrial wastes and toxic chemicals. This type of treatment should ideally take place at the industrial plant itself, before discharge of their effluent in municipal sewers or water courses.
Widely used terminology refers to three levels of wastewater treatment: primary, secondary, and tertiary (or advanced).
Primary (mechanical) treatment is designed to remove gross, suspended and floating solids from raw sewage. It includes screening to trap solid objects and sedimentation by gravity to remove suspended solids. This level is sometimes referred to as “mechanical treatment”, although chemicals are often used to accelerate the sedimentation process. Primary treatment can reduce the BOD of the incoming wastewater by 20-30% and the total suspended solids by some 50-60%. Primary treatment is usually the first stage of wastewater treatment. Many advanced wastewater treatment plants in industrialized countries have started with primary treatment, and have then added other treatment stages as wastewater load has grown, as the need for treatment has increased, and as resources have become available.
Secondary (biological) treatment removes the dissolved organic matter that escapes primary treatment. This is achieved by microbes consuming the organic matter as food, and converting it to carbon dioxide, water, and energy for their own growth and reproduction. The biological process is then followed by additional settling tanks (“secondary sedimentation", see photo) to remove more of the suspended solids. About 85% of the suspended solids and BOD can be removed by a well running plant with secondary treatment. Secondary treatment technologies include the basic activated sludge process, the variants of pond and constructed wetland systems, trickling filters and other forms of treatment which use biological activity to break down organic matter.
Tertiary treatment is simply additional treatment beyond secondary! Tertiary treatment can remove more than 99 percent of all the impurities from sewage, producing an effluent of almost drinking-water quality. The related technology can be very expensive, requiring a high level of technical know-how and well trained treatment plant operators, a steady energy supply, and chemicals and specific equipment which may not be readily available. An example of a typical tertiary treatment process is the modification of a conventional secondary treatment plant to remove additional phosphorus and nitrogen.
Disinfection, typically with chlorine, can be the final step before discharge of the effluent. However, some environmental authorities are concerned that chlorine residuals in the effluent can be a problem in their own right, and have moved away from this process. Disinfection is frequently built into treatment plant design, but not effectively practiced, because of the high cost of chlorine, or the reduced effectiveness of ultraviolet radiation where the water is not sufficiently clear or free of particles.
Article by The World Bank Group
