Vegetable Plants, animals and human beings are the sources for origination of natural or synthetic organic compounds. Human excreta, paper products, detergents, cosmetics, food, agricultural products, wastes from commercial activities and wastes from industrial sources are organic in origin and considerable in quantity.
Organic compounds generated from the above sources are a combination of carbon, hydrogen, oxygen, nitrogen, sulfur and other trace elements. Organic compounds such as proteins, carbohydrates, and fats are degradable by organisms, however they can cause pollution.
Large concentration of degradable organics in wastewater is dangerous to lakes, streams, and oceans, because organisms consume dissolved oxygen in water to break down the wastes. This can reduce or deplete the supply of oxygen in the water needed by aquatic life, resulting in fish kills, increasing the odors, and overall deterioration of water quality.
Some organic compounds are more stable than others and cannot be quickly broken down by organisms. This poses an additional challenge for treatment. This is true with many synthetic organic compounds developed for agriculture and industry. Some of the synthetic organic compounds that belong to pesticides, herbicides, dyes, pigments, fried oils, and fried meats are toxic to humans, fish, and aquatic plants and often are disposed off improperly in drains or carried in storm-water. In receiving water bodies, they kill or contaminate fish, making them unfit to eat. They also can reduce the efficiency of the processes in treatment.
[This blog has a Help Desk. Please post your queries there, with your Contact details if you want to be contacted. If your query is simple enough, I’ll try and answer back thru Help Desk. If it can only be answered by a specialist, I’ll try to identify a Subject Matter Expert (SME) in the relevant realm, and get him/ her to reply, thru this Help Desk or thru email. If your query is consultative in nature, she/ he may expect a fee, though.]
Important wastewater contaminants and quality factors:
The presence of contaminants (or pollutants) in wastewater leads to the reduction of water quality and consequently interferes with its reuse. Presence of these contaminants also prevents the direct disposal of wastewater into environment since it degrades the quality of water and soil.
The table below lists:
# The contaminant sources
# The type of wastewater
# The effect
Wastewater is categorized in terms of:
# Quality factors
# Quality parameters
# Tests
The physical parameters include:
# Temperature (which affects rates of chemical and biochemical reactions)
# Viscosity (and hence efficiency of sedimentation of settleable solids)
# Solubility of gases
# Odor
# Color
# Solids
The physical characteristics help assessing the condition of domestic wastewater, whether fresh or septic and its earlier incarnations, for example ground water and/or industrial
wastewaters mixed with domestic wastewater.
The chemical quality of wastewater can be determined by studying the following:
# pH
# Alkalinity
# Chlorides
# Various forms of nitrogen
# Phosphorous
# Sulfur
# Heavy metals
# Toxic substances
# Gases
Above all, tests like BOD, COD, and TOC (which are used to estimate the organic content either directly or indirectly as oxygen consumed by organic matter).
The BOD test, in spite of its limitation, which is large time requirement (5 days), is a universally used test as it measures the biodegradable fraction of organic matter, unlike any other test.
Strength:
The strength of wastewater depends mainly on the degree of dilution. The wastewater characteristics can vary widely with local conditions, hour of the day, day of the week, season, and types of sewers
[This blog has a Help Desk. Please post your queries there, with your Contact details if you want to be contacted. If your query is simple enough, I’ll try and answer back thru Help Desk. If it can only be answered by a specialist, I’ll try to identify a Subject Matter Expert (SME) in the relevant realm, and get him/ her to reply, thru this Help Desk or thru email. If your query is consultative in nature, she/ he may expect a fee, though.]
Volume of wastewater discharge:
Wastewater is a combination of excreta, flushing water and other gray-water or sullage and is much diluted depending on the per capita water uses. The personal water consumption alone is between 200 and 300 liters per day. When the industrial and energy production usage is added to the equation, fresh water usage exceeds 5,000 liters per day on a per capita basis.
The volume of wastewater discharge can be reduced substantially through conservation of water. This is a good idea for a number of reasons:
# It lowers monthly water bills
# It can also reduce the money that homeowners and communities spend for wastewater treatment.
# Increased efficiency of wastewater treatment plant and savings on energy costs.
# Significant reduction in wastewater flows also can save on personnel costs, such as overtime, and can eliminate or
postpone the need to upgrade or expand facilities. It lowers sewer charges and taxes for homeowners. Water conservation also directly benefits homeowners with onsite systems. Simply by reducing water use, homeowners can extend the life of their systems for many years, prevent system failures, and minimize maintenance costs, potentially saving hundreds of dollars.
# Water conservation also indirectly helps in maintaining the water quality. Excessive water drawing (exceeding the water holding capacity of the soil) from ground sources allows ground water contamination from neighboring areas or sea. So, avoid unnecessary water drawing from ground sources.
[This blog has a Help Desk. Please post your queries there, with your Contact details if you want to be contacted. If your query is simple enough, I’ll try and answer back thru Help Desk. If it can only be answered by a specialist, I’ll try to identify a Subject Matter Expert (SME) in the relevant realm, and get him/ her to reply, thru this Help Desk or thru email. If your query is consultative in nature, she/ he may expect a fee, though.]
When water becomes wastewater:
The potable water becomes wastewater after it gets contaminated with natural or synthetic microbiological compounds that arises out of human activities, commercial and industrial sources. They may be accompanied with surface water, ground water and storm water. Wastewater is sewage, storm-water and water that have been used for various purposes around the community. Unless properly treated, wastewater can harm public health and the environment. Most communities generate wastewater from both residential and nonresidential sources.
Residential wastewater:
Although the word sewage usually brings toilets to mind, it is actually used to describe all types of wastewater generated from every room in a house. In the U.S, sewage varies regionally and from home to home. They are based on factors such as the number and type of water-using fixtures and appliances, the number of occupants, their ages, and even their habits, such as the types of food they eat. However, when compared to the variety of wastewater flows generated by different nonresidential sources, household wastewater shares many similar characteristics overall. There are two types of domestic sewage: black-water or wastewater from toilets, and gray water, which is wastewater from all sources except toilets. Black-water and gray-water have different characteristics, but both contain pollutants and disease causing agents that require treatment.
Nonresidential wastewater:
Nonresidential wastewater in small communities is generated by diverse sources like offices, businesses, Super markets, restaurants, schools, hospitals, farms, manufacturers, and other commercial, industrial, and institutional entities. Storm-water is a nonresidential source and carries trash and other pollutants from streets, as well as pesticides and fertilizers from yards and fields.
Because of the different nonresidential wastewater characteristics, communities need to assess each source individually or compare similar types of nonresidential sources to ensure that adequate treatment is provided. For example, public restrooms may generate wastewater with some characteristics similar to sewage, but usually at higher volumes and at different peak hours. The volume and pattern of wastewater flows from rental properties, hotels, and recreation areas often vary seasonally as well.
Laundries differ from many other nonresidential sources because they produce high volumes of wastewater containing lint fibers. Restaurants typically generate a lot of oil and grease. It may be necessary to provide pretreatment of oil and grease from restaurants or to collect it prior to treatment. For example, by adding grease traps to septic tanks.
Wastewater from some nonresidential sources also may require additional treatment. For example, storm-water should be collected separately to prevent the flooding of treatment plants during wet weather. Screens often remove trash and other large solids from storm sewers. In addition, many industries produce wastewater high in chemical and biological pollutants that, can overburden onsite and community systems. Dairy farms and breweries are good examples. Communities may require these types of nonresidential sources to provide their own treatment or preliminary treatment to protect community systems and public health.
[This blog has a Help Desk. Please post your queries there, with your Contact details if you want to be contacted. If your query is simple enough, I’ll try and answer back thru Help Desk. If it can only be answered by a specialist, I’ll try to identify a Subject Matter Expert (SME) in the relevant realm, and get him/ her to reply, thru this Help Desk or thru email. If your query is consultative in nature, she/ he may expect a fee, though.]
To be Notified
click the following button:
