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.
Water treatment is any process that improves the quality of water to make it appropriate for a specific end-use. The end use may be drinking,industrial water supply,irrigation,river flow maintenance,water recreation or many other uses,including being safely returned to the environment. Water treatment removes contaminants and undesirable components,or reduces their concentration so that the water becomes fit for its desired end-use. This treatment is crucial to human health and allows humans to benefit from both drinking and irrigation use.
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.
Parabens are chemicals that are commonly used as preservatives in cosmetic and pharmaceutical products. Chemically,they are a series of parahydroxybenzoates or esters of parahydroxybenzoic acid. Research is being conducted to evaluate the potential health implications of paraben usage.
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.
Waste stabilization ponds are ponds designed and built for wastewater treatment to reduce the organic content and remove pathogens from wastewater. They are man-made depressions confined by earthen structures. Wastewater or "influent" enters on one side of the waste stabilization pond and exits on the other side as "effluent",after spending several days in the pond,during which treatment processes take place.
The activated sludgeprocess is a type of biological wastewater treatment process for treating sewage or industrial wastewaters using aeration and a biological floc composed of bacteria and protozoa. It is one of several biological wastewater treatment alternatives in Secondary Treatment,which deals with the removal of biodegradable organic matter and suspended solids. It uses air and microorganisms to biologically oxidize organic pollutants,producing a waste sludge containing the oxidized material.
Industrial wastewater treatment describes the processes used for treating wastewater that is produced by industries as an undesirable by-product. After treatment,the treated industrial wastewater may be reused or released to a sanitary sewer or to a surface water in the environment. Some industrial facilities generate wastewater that can be treated in sewage treatment plants. Most industrial processes,such as petroleum refineries,chemical and petrochemical plants have their own specialized facilities to treat their wastewaters so that the pollutant concentrations in the treated wastewater comply with the regulations regarding disposal of wastewaters into sewers or into rivers,lakes or oceans. This applies to industries that generate wastewater with high concentrations of organic matter,toxic pollutants or nutrients such as ammonia. Some industries install a pre-treatment system to remove some pollutants,and then discharge the partially treated wastewater to the municipal sewer system.
An aerated lagoon is a simple wastewater treatment system consisting of a pond with artificial aeration to promote the biological oxidation of wastewaters.
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.
Aerobic granular reactors (AGR) or Aerobic granular sludge (AGS) are a community of microbial organisms,typically around 0.5-3mm in diameter,that remove carbon,nitrogen,phosphorus and other pollutants in a single sludge system. It can also be used for wastewater treatments. Aerobic granular sludge is composed of bacteria, protozoa and fungi,which allows oxygen to follow in and biologically oxidize organic pollutants. AGS is a type of wastewater treatment process for sewages and/or industrial waste treatment. AGR was first discovered by UK engineers,Edward Ardern and W.T. Lockett who were researching better ways for sewage disposal. Another scientist by the name of Dr. Gilbert Fowler,who was at the University of Manchester working on an experiment based on aeration of sewage in a bottle coated with algae. Eventually,all three scientists were able to collaborate with one another to discover AGR/AGS.
Advanced oxidation processes (AOPs),in a broad sense,are a set of chemical treatment procedures designed to remove organic (and sometimes inorganic) materials in water and wastewater by oxidation through reactions with hydroxyl radicals (·OH). In real-world applications of wastewater treatment,however,this term usually refers more specifically to a subset of such chemical processes that employ ozone (O3),hydrogen peroxide (H2O2) and UV light or a combination of the few processes.
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.
A rotating biological contactor or RBC is a biological fixed-film treatment process used in the secondary treatment of wastewater following primary treatment. The primary treatment process involves removal of grit,sand and coarse suspended material through a screening process,followed by settling of suspended solids. The RBC process allows the wastewater to come in contact with a biological film in order to remove pollutants in the wastewater before discharge of the treated wastewater to the environment,usually a body of water. A rotating biological contactor is a type of secondary (biological) treatment process. It consists of a series of closely spaced,parallel discs mounted on a rotating shaft which is supported just above the surface of the wastewater. Microorganisms grow on the surface of the discs where biological degradation of the wastewater pollutants takes place.
Ozonia is a multinational water treatment equipment manufacturer headquartered in Zürich,Switzerland.
The adsorption/bio-oxidation process is a two-stage modification of the activated sludge process used for wastewater treatment. It consists of a high-loaded A-stage and low-loaded B-stage. The process is operated without a primary clarifier,with the A-stage being an open dynamic biological system. Both stages have separate settling tanks and sludge recycling lines,thus maintaining unique microbial communities in both reactors.
Kartik Chandran is an American environmental engineer at Columbia University,where he is a professor in the Department of Earth and Environmental Engineering. He primarily works on the interface between environmental molecular and microbiology,environmental biotechnology and environmental engineering. The focus of his research is on elucidating the molecular microbial ecology and metabolic pathways of the microbial nitrogen cycle. Applications of his work have ranged from energy and resource efficient treatment of nitrogen containing wastewater streams,development and implementation of sustainable approaches to sanitation to novel models for resource recovery. Under his stewardship,the directions of biological wastewater treatment and biological nutrient removal were established for the first ever time in the history of Columbia University.
Moving bed biofilm reactor (MBBR) is a type of wastewater treatment process that was first invented by Professor Hallvard Ødegaard at Norwegian University of Science and Technology in the late 1980s. The process takes place in an aeration tank with plastic carriers that a biofilm can grow on. The compact size and cheap wastewater treatment costs offers many advantages for the system. The main objective of using MBBR being water reuse and nutrient removal or recovery. In theory,wastewater will be no longer considered waste,it can be considered a resource.
Imre Takács is a Hungarian-Canadian environmental engineer and process engineer. He is a founder and CEO of Dynamita SARL,based in France,and developer of process simulators and dynamic models for wastewater treatment plants.
