Environmental engineering is a professional engineering discipline related to environmental science. It encompasses broad scientific topics like chemistry,biology,ecology,geology,hydraulics,hydrology,microbiology,and mathematics to create solutions that will protect and also improve the health of living organisms and improve the quality of the environment. Environmental engineering is a sub-discipline of civil engineering and chemical engineering. While on the part of civil engineering,the Environmental Engineering is focused mainly on Sanitary Engineering.
Stormwater,also written storm water,is water that originates from precipitation (storm),including heavy rain and meltwater from hail and snow. Stormwater can soak into the soil (infiltrate) and become groundwater,be stored on depressed land surface in ponds and puddles,evaporate back into the atmosphere,or contribute to surface runoff. Most runoff is conveyed directly as surface water to nearby streams,rivers or other large water bodies without treatment.
Permeable paving surfaces are made of either a porous material that enables stormwater to flow through it or nonporous blocks spaced so that water can flow between the gaps. Permeable paving can also include a variety of surfacing techniques for roads,parking lots,and pedestrian walkways. Permeable pavement surfaces may be composed of;pervious concrete,porous asphalt,paving stones,or interlocking pavers. Unlike traditional impervious paving materials such as concrete and asphalt,permeable paving systems allow stormwater to percolate and infiltrate through the pavement and into the aggregate layers and/or soil below. In addition to reducing surface runoff,permeable paving systems can trap suspended solids,thereby filtering pollutants from stormwater.
Wastewater treatment is a process which removes and eliminates contaminants from wastewater. It thus converts it into an effluent that can be returned to the water cycle. Once back in the water cycle,the effluent creates an acceptable impact on the environment. It is also possible to reuse it. This process is called water reclamation. The treatment process takes place in a wastewater treatment plant. There are several kinds of wastewater which are treated at the appropriate type of wastewater treatment plant. For domestic wastewater the treatment plant is called a Sewage Treatment. Municipal wastewater or sewage are other names for domestic wastewater. For industrial wastewater,treatment takes place in a separate Industrial wastewater treatment,or in a sewage treatment plant. In the latter case it usually follows pre-treatment. Further types of wastewater treatment plants include Agricultural wastewater treatment and leachate treatment plants.
Water reclamation is the process of converting municipal wastewater or sewage and industrial wastewater into water that can be reused for a variety of purposes. It is also called wastewater reuse,water reuse or water recycling. There are many types of reuse. It is possible to reuse water in this way in cities or for irrigation in agriculture. Other types of reuse are environmental reuse,industrial reuse,and reuse for drinking water,whether planned or not. Reuse may include irrigation of gardens and agricultural fields or replenishing surface water and groundwater. This latter is also known as groundwater recharge. Reused water also serve various needs in residences such as toilet flushing,businesses,and industry. It is possible to treat wastewater to reach drinking water standards. Injecting reclaimed water into the water supply distribution system is known as direct potable reuse. Drinking reclaimed water is not typical. Reusing treated municipal wastewater for irrigation is a long-established practice. This is especially so in arid countries. Reusing wastewater as part of sustainable water management allows water to remain an alternative water source for human activities. This can reduce scarcity. It also eases pressures on groundwater and other natural water bodies.
A constructed wetland is an artificial wetland to treat sewage,greywater,stormwater runoff or industrial wastewater. It may also be designed for land reclamation after mining,or as a mitigation step for natural areas lost to land development. Constructed wetlands are engineered systems that use the natural functions of vegetation,soil,and organisms to provide secondary treatment to wastewater. The design of the constructed wetland has to be adjusted according to the type of wastewater to be treated. Constructed wetlands have been used in both centralized and decentralized wastewater systems. Primary treatment is recommended when there is a large amount of suspended solids or soluble organic matter.
A retention basin, sometimes called a retention pond,wet detention basin,or storm water management pond (SWMP),is an artificial pond with vegetation around the perimeter and a permanent pool of water in its design. It is used to manage stormwater runoff,for protection against flooding,for erosion control,and to serve as an artificial wetland and improve the water quality in adjacent bodies of water.
Blackwater in a sanitation context denotes wastewater from toilets which likely contains pathogens that may spread by the fecal–oral route. Blackwater can contain feces,urine,water and toilet paper from flush toilets. Blackwater is distinguished from greywater,which comes from sinks,baths,washing machines,and other household appliances apart from toilets. Greywater results from washing food,clothing,dishes,as well as from showering or bathing.
Rain gardens,also called bioretention facilities,are one of a variety of practices designed to increase rain runoff reabsorption by the soil. They can also be used to treat polluted stormwater runoff. Rain gardens are designed landscape sites that reduce the flow rate,total quantity,and pollutant load of runoff from impervious urban areas like roofs,driveways,walkways,parking lots,and compacted lawn areas. Rain gardens rely on plants and natural or engineered soil medium to retain stormwater and increase the lag time of infiltration,while remediating and filtering pollutants carried by urban runoff. Rain gardens provide a method to reuse and optimize any rain that falls,reducing or avoiding the need for additional irrigation. A benefit of planting rain gardens is the consequential decrease in ambient air and water temperature,a mitigation that is especially effective in urban areas containing an abundance of impervious surfaces that absorb heat in a phenomenon known as the heat-island effect.
Robert A. (Bob) Gearheart is an emeritus professor of environmental engineering at Cal Poly Humboldt,in Arcata,California.
Sustainable drainage systems are a collection of water management practices that aim to align modern drainage systems with natural water processes and are part of a larger green infrastructure strategy. SuDS efforts make urban drainage systems more compatible with components of the natural water cycle such as storm surge overflows,soil percolation,and bio-filtration. These efforts hope to mitigate the effect human development has had or may have on the natural water cycle,particularly surface runoff and water pollution trends.
Secondary treatment is the removal of biodegradable organic matter from sewage or similar kinds of wastewater. The aim is to achieve a certain degree of effluent quality in a sewage treatment plant suitable for the intended disposal or reuse option. A "primary treatment" step often precedes secondary treatment,whereby physical phase separation is used to remove settleable solids. During secondary treatment,biological processes are used to remove dissolved and suspended organic matter measured as biochemical oxygen demand (BOD). These processes are performed by microorganisms in a managed aerobic or anaerobic process depending on the treatment technology. Bacteria and protozoa consume biodegradable soluble organic contaminants while reproducing to form cells of biological solids. Secondary treatment is widely used in sewage treatment and is also applicable to many agricultural and industrial wastewaters.
Sewage treatment is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable to discharge to the surrounding environment or an intended reuse application,thereby preventing water pollution from raw sewage discharges. Sewage contains wastewater from households and businesses and possibly pre-treated industrial wastewater. There are a high number of sewage treatment processes to choose from. These can range from decentralized systems to large centralized systems involving a network of pipes and pump stations which convey the sewage to a treatment plant. For cities that have a combined sewer,the sewers will also carry urban runoff (stormwater) to the sewage treatment plant. Sewage treatment often involves two main stages,called primary and secondary treatment,while advanced treatment also incorporates a tertiary treatment stage with polishing processes and nutrient removal. Secondary treatment can reduce organic matter from sewage, using aerobic or anaerobic biological processes. A so-called quarternary treatment step can also be added for the removal of organic micropollutants,such as pharmaceuticals. This has been implemented in full-scale for example in Sweden.
Water-sensitive urban design (WSUD) is a land planning and engineering design approach which integrates the urban water cycle,including stormwater,groundwater,and wastewater management and water supply,into urban design to minimise environmental degradation and improve aesthetic and recreational appeal. WSUD is a term used in the Middle East and Australia and is similar to low-impact development (LID),a term used in the United States;and Sustainable Drainage System (SuDS),a term used in the United Kingdom.
A vermifilter is an aerobic treatment system,consisting of a biological reactor containing media that filters organic material from wastewater. The media also provides a habitat for aerobic bacteria and composting earthworms that purify the wastewater by removing pathogens and oxygen demand. The "trickling action" of the wastewater through the media dissolves oxygen into the wastewater,ensuring the treatment environment is aerobic for rapid decomposition of organic substances.
Decentralized wastewater systems convey,treat and dispose or reuse wastewater from small and low-density communities,buildings and dwellings in remote areas,individual public or private properties. Wastewater flow is generated when appropriate water supply is available within the buildings or close to them.
William Joseph Oswald was an American educator,scientist,and engineer who spent his entire academic career at the University of California,Berkeley in the departments of Civil and Environmental Engineering and Public Health. He made foundational contributions to the fields of wastewater treatment and applied phycology,or as he called it,"algology". Throughout a career spanning more than five decades,Oswald was the primary academic advisor to more than two dozen doctoral students,sat on more than 100 additional masters and doctoral thesis committees,and taught seminal courses in applied algology.
Rainwater management is a series of countermeasures to reduce runoff volume and improve water quality by replicating the natural hydrology and water balance of a site,with consideration of rainwater harvesting,urban flood management and rainwater runoff pollution control.
Richard O. Mines Jr. is an American civil/environmental engineer,academic,and author. He is an emeritus professor of environmental and civil engineering at Mercer University. His research is primarily focused on the activated sludge process and biological nutrient removal processes,with particular emphasis on environmental engineering,water treatment,biosolids treatment,and engineering education.
Aisling Dominique O'Sullivan is an Irish–New Zealand academic,and is a full professor at the University of Canterbury,specialising in ecological engineering for removal of heavy metals and nutrients from wastewater,in urban and rural environments and as part of mining remediation.
