Wastewater Treatment Processes PDF

WASTEWATER DEFINITION OF TERMS Wastewater - Contaminated Water - Also known as Sewerage - Consists of Storm Runoffs and Other Human Related Activities Sludge - Wastewater Tratment Byproduct - Mix of Organic Matter form Human Wate, Food Waste, etc. Wastewater Engineering - A field in Engineering with...

WASTEWATER DEFINITION OF TERMS Wastewater - Contaminated Water - Also known as Sewerage - Consists of Storm Runoffs and Other Human Related Activities Sludge - Wastewater Tratment Byproduct - Mix of Organic Matter form Human Wate, Food Waste, etc. Wastewater Engineering - A field in Engineering with the Objective to Keep the Environment and People from Harm due to Undtreated Wastewater Wastewater Treatment - A process of converting Wastewater to clean and treated Water Influent - Wastewater is flowing INTO the treatment plant Effluent - Wastewater flowing FROM the treatment plant TYPES OF WASTEWATER ❖ Black Water ➢ Toilet ➢ Kitchen ➢ Dishwasher Waste ❖ Gray WAter ➢ Showers ➢ Laundry ➢ Bathroom Sink Waste ❖ Yellow Water ➢ Pure Urine Waste SOURCES OF WASTEWATER ❖ Storm Runoff ➢ Melted Snow ➢ Rain from Roof ➢ Rooftops ➢ Roads ❖ Domestic Wastewater ➢ Household ➢ Public and Commercial Faciities ❖ Industrial Wastewater ➢ Manufacturing Plants ■ Contains significant amounts of contaminants COMMON POLLUTANTS OF WASTEWATER ❖ Physical ❖ Chemical ❖ Biological HEALTH & ENVIRONMENTAL IMPACT OF WASTEWATER - Wastewater consists of microorganisms that may cause diseases. - It is a Potential Threat ❖ Severe Water Pollution ❖ Eutophication ❖ Disrupt the Balance GENERAL PROCESSES IN A SEWERAGE TREAMENT PLANT ❖ Primary Treatment ➢ Separates Wastewater through Sedimentation Tank ➢ Solid Materials or Sludge are pumped away to be dewatered ➢ Either Incinerated or Dumped in a Landfill ❖ Secondary/Biological Treatment ➢ Exposes wastewater to bacteria ➢ Uses Bacteria and Microbes ➢ Microbes can consume and break apart organic materials in the wastewater ❖ Wastewater Disinfection ➢ Sterilizes/Sanitizes the Wastewater ➢ Filled with bacteria and Microbes ➢ After this step, wastewater is released back to nearby waterwaste TREATMENT SYSTEMS (Secondary Treatment) ❖ Fixed-Film Treatment System ➢ Uses an inert medium that can support the growth of biomass/microbes ➢ Once Waster passes through the film. The microbes on the film break down any matter or material in wastewater ❖ Aeration Treatment System ➢ Air is Pumped into the wastewater causing bubbles ➢ Excess Air promotes rapid bacterial growth ➢ These bacteria digest matter and material in wastewater PROCESS (Wastewater Disinfection) ❖ Chlorination ➢ Adds Chlorine to wastewater to remove bacteria and microbes ➢ Negative effects in Environement ❖ Ultra-Violet Disinfection ➢ Safer method ➢ No chemical used ➢ Requires more energy GENERAL PROCESSES IN A SEWERAGE TREATMENT PLANT BENEFIT OF SEWERAGE TREATMENT PLANT ❖ Waste Water Reduction ❖ Energy Production ❖ Fertilizer Production CONSTRUCTED WETLANDS Components ❖ Wetland Cells ➢ Made up of one or more shallow interconnected basins or cells ➢ Engineered substrates to promote water treatment ❖ Substrate Materials ➢ Facilitiate Microbial Attachment ■ Gravel ■ Sand ■ Limestone ■ Specialized Media ❖ Wetlland Plants ➢ Cells are planted with indigenous wetland plants ➢ Essential for water treatment ❖ Water Distribution System ➢ System of Pipes or Channels ➢ Distribute wastewater uniformly throughout the wetland cells ❖ Monitoring and Control Equipment ➢ Utilized to Track water quality parameters to ensure treatment process is effective ■ pH Level ■ Dissolved Oxygen ■ Nutrient concentrations Types of Constructed Wetlands ❖ Surface Flow Wetlands ➢ Wastewater flows over the surface of wetland cells ➢ Providing contact with plants and substrate ❖ Subsurface Flow Wetlands ➢ Wastewater is directed through the substrate and plant root zone below the surface ❖ Hybrid Wetland ➢ Systems combine both surface and subsurface flow components to optimize treatment efficiency Applications of Wetlands ❖ Municipal Wastewater Treatment ➢ Constructed Wetlands can be integrated into municipal wastewater treatment plants to provide secondary or even tertiary treatment ❖ Industrial Wastewater Treatment ➢ Used to treat various industrial effluents ■ Food processing ■ Mining ■ Chemical Manufacturing ❖ Stormwater Management ➢ Help control and treat stormwater runoff ➢ Remove Poluutants ➢ Reducing Flooding ❖ Habitat Resoration ➢ Enhance wildlife habitat and biodiversity ➢ Providing Valuable Ecosystem services Benefits of Constructed Wetland ❖ Effective Removal of Pollutants ➢ Organic Matter ➢ Nutrients ➢ Heavy Metal ➢ Pathogens ❖ Low operational and Maintenance costs compared to conventional treatment technologies ❖ Improved Aesthetics and Wildlife Habitat ❖ Sustainable and Ecofriendly SANITATION PROGRAMS IN INFORMAL SETTLEMENTS The United Nations Educational, Scientific, and Cultural Organization (UNESCO) defines informarmal settlements or slums as “ a contiguous settlement where the inhabitants are characterized as having inadequate housing and basic services” Significance of Sanitation Programs in Informal Settlements ❖ ❖ ❖ ❖ Access to Proper Sanitation Facilities Safe Drinking Water Hygiene Promotion Health and Disease Prevention WATER REUSE - The use of treated wastewater for beneficial purposes, which increases an community’s available water supply and makes it more reliable, especially in times of drought Various Application of Water Reuse ❖ Irrigation ➢ Most common uses of reclaimed water is for agricultural irrigation. ➢ Treated wastewater is well suited for this purpose because it provides a consistent source of water even during dry seasons ➢ Reduces the demand on freshwater sources for agriculture ➢ Prevent the contamination of natural water bodies with nutrients and chemical frm untreated runoff ❖ Industrial Processes ➢ Require large quantities of water ➢ Cooling ➢ Manufacturing ➢ Cleaning ➢ Uses reclaimed water ❖ Landscaping and Recreational Uses ➢ Reclaimed water is used for landscaping ■ Parks ■ Golf Course ■ Green Spaces ➢ Reclaimed water reduces the demand on potable water supplies ❖ Construction and Dust Control ➢ Reclaimed water used for dust control and compaction, reducing the need for freshwater ➢ Useful in areas where water resources are scarce ❖ Aquifer Recharge and Environmental Enhancement ➢ Treated water is injected into underground aquifers to replenish groundwater supplies ■ Known as Indirect potable reuse ■ Allowing water to undergo natural filtration and purification ❖ Toilet Flushing and Industrial Boiler Feeds ➢ Reclaimed water used for toilet flushing ➢ Used as a feedwater source for boilers ➢ Reduce demand for freshwater for non-potable uses within the facility ❖ Direct Potable Reuse ➢ Advanced water treatment techology ➢ To purify reclaimed water for potable standards ➢ Involves multiple treatment barriers ■ Advanced Filtration ■ UV disinfection ■ Chemical Processes ➢ Complex and highly regulated process SEPTIC SYSTEMS - A kind of wastewater treatment system - Decentralized and often employed in rural and suburban parts of the country that do not have access to centralized sewage systems - Properly treat and dispose wastewater from households - Use a combination of biological and mechanical processes Components of a Septic System ❖ Septic Tank ➢ Buried ➢ Watertight Container ➢ Typically made of: ■ Concrete ■ Fiberglass ■ Polythylene ➢ Receives all wastewater from the house ❖ Distribution Box ➢ Drain Fields ■ Also known as Leach Fields ➢ Used to enely distribute effluent from the septic tank to the drain pipes ❖ Drain Field ➢ Also known as Leach Field ➢ Network of Perforated pipes buried intrenches filled with gravel or sand How a Septic System Works 1. Wastewater Generation a. Toilets, Sinks, Showers, WAshing Machines, and other household sources flows in to the septic tank 2. Separation a. Solid settle in the bottom (forms sludge) b. Scum Floats to the Top c. Remaining liquid called effluent 3. Distribution to Drain Field a. Distributes Effluent into the drain field pipes 4. Treatment in the Soil a. Happens in Drain field b. Effluent Distributed in Soil c. Natural Filtration d. Water re-enters the groundwater 5. Maintenance a. Pumping out septic tank every 3-5 years b. Remove accumulated solids Advantages of Septic Tank ❖ Decentralized treatment ❖ Can be installed in areas without access to centralized sewage treatment facilities ❖ Lower environmental impact ❖ Rely on Natural Processes ❖ Reduce risk of pollutants