محاضرة 1 مقدمة في معالجة مياه الصرف الصحي

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ومضات المعرفة

Keywords:

Lecture (Type Of Public Presentation),Sewage Treatment,بكتيريا,معالجة بيولوجية,معالجة حيوية,ملوثات عضوية,محطة المعالجة,معالجة مياه الصرف الصحي,معالجة المياه,organic pollutants,treatments plants,sewage treatments plants,sewage treatments,sewage,Jules van Lier,Water Treatment,كورس,دورة تدريبية

Subtitles:
what do we do with the collected waters that we used in households and industries we'll dump them in the environment well know welcome to the lecture series introduction to urban sewage treatment as part of our water treatment course my name is Julia and I'm professor in wastewater treatment and environmental engineering at the sanitary engineering section of tu Delft in this part of the course we will discuss the characteristics of urban sewage as well as the common treatment technologies that are applied in the Netherlands in our follow up master courses we are focusing on advanced technologies as well as alternative technologies that are recently developed to reach a higher degree of sustainability following the urban water chain to treat it and distribute the drinking water finds its way to all household and industrial appliances at both uses water is generally used for cleaning or transport of waste products and the only a very limited amount is actually used for drinking in fact less than 1% of the water supply to the households therefore the use waters contain many suspended pollutants and in addition because water is a polar solvent many pollutants will dissolve in the water the water which is suspended and the salt pollutants is now called waste water or sewage and is carried away from the side of use collection of the used urban waters is generally done by means of an extensive sewerage Network which conveys the urban sewage to the side of treatment the term used urban waters over wastewater effect better describes the state of the water and therefore has my strong preference moreover wastewater implicitly is negatively valued water that is wasted and it needs treatment prior to discharge into an environmental sink use urban waters is more positively a calls for treatment for reuse this can be the water it's or the various pollutants that can be recovered as a resource in fact the term used urban waters better fits in the urban water cycle idea the central theme of our entire course the collected sewage is treated at a sewage treatment plant or wastewater treatment plant the sewage treatment plant consists of several functional units each targeting a specific group of pollutants such unit may consist of physical treatment chemical treatment biological treatment electrochemical treatment or combinations of these types of treatments we have to realize that every single cubic metre of drinking water will ultimately become one cubic meter of wastewater and that may impact many cubic meters of surface water or even groundwater when it's discharged without treatment since the self attenuation of these waters is very limited such discharge will lead to severe environmental impacts in order to protect the environment financial investments have to be made to establish treatment technologies and particularly in congested areas or urban settlements and control discharge of large sewage flows is conceived problematic we also have to realize that large areas in the world are yet deprived from adequate sewage collection and proper treatment for instance in Latin America less than 20 percent of the sewage is collected and treated rare isn't a year this is less than 40 percent here in the Netherlands about 100 percent of all households are connected to the sewage network and finally to a sewage treatment plant in this part of our introductory course we will specifically discuss the setup and functionality of the sewage treatment plants that are currently in operation in the Netherlands what will we learn the coming lectures first as any disciplinary field also wastewater treatment engineering has its typical terminology we need to acquaint ourselves to this terminology second why do we need to treat these waters or in other words what is their environmental impact they are discharged and treated third we need to understand the nature of the pollutants and the characteristics of the sewage in general fourth how does a sewage treatment plant look like and what are all the functional units in fact doing in the treatment plant by finishing this course we should be able to design a full-scale sewage treatment plant using the design features commonly applied in the Netherlands how does it sewage or wastewater treatment plant looks like this picture shows the largest sewage treatment plant in the Netherlands here in Delft it has the capacity to treat the sewage of about 1.4 million people it's a modern treatment plant that removes organic matter as well as nutrients phosphorus and nitrogen from the used water but to the restrictions set by law this picture looks great right but how does it function the sewage treatment plant consists of various treatment units of which some make use of physical removal and order of biochemical removal you see screens settling tanks bio reactors excess sludge treatment facilities and more the effluent of the treatment plant is low in organic pollution and lower nutrients you will see this slide very often in the course and every time we will discuss a functional unit inside this treatment plant we will indicate exactly where we are in the treatment plant we hope that this approach will facilitate your comprehension of the entire treatment setup without getting lost in various functional units and since when do we treat the urban sewage the obligation to treat the sewage up to standards prior to discharge follows the deplorable state of our surface water in the 60s of the past century lifeless surface waters were common and species diversity was at stake only in the early 70s the Clean Water Act was approved by our government and from that time onwards it was forbidden to discharge without treatment at the same time a cost recovery system was invented this appears to be successful up to des the polluter pay principle and what does this polluter pay principle mean well every person daily discharges a certain amount of carbon and nutrients this amount of pollutants is therefore denominated F person equivalent abbreviated by PE the person equivalent of pollutants is subsequently translated in money in cash consequently every person receives a bill for the cost that are required to treat these pollutants and up to date we pay up to 80 euros per person per year for supporting the institutions who are responsible for reaching the requested water quality at the treatment plants in this way it is also easy to calculate how much an industry has to pay when a discharge is a certain amount of pollutants just divide the total amount by the person equivalent amount the untreated discharge of organic matter was already forbidden in the Netherlands early 70s of the last century however the uncontrolled discharge of nutrients phosphorus and nitrogen was only regulated in 90s in agreement with our neighboring countries in the so-called North Sea treaty at present we expect even stricter regulation as set by the European framework directive and adapted Dutch regulations and where these regulations effective well yes this table shows the average influent effluent values of the major sewage pollutants the organic pollutants are indicated by the parameter C OD and b OD which will be explained later in the course nitrogen pollutants I indicated as total n and phosphorus as total P this settled this edible solids are termed as SS in every sewage treatment plant the effluent restrictions are met as you can see in the Netherlands in all treatment plants the biological reactor plays a central and crucial role in meeting the requirements particularly the requirement for treating goodnight the nutrients nitrogen and phosphorus to a low level decrease the amount of organic matter in the effluent drastically as indicated in this table therefore biological treatment is often considered the central core of the system and will be discussed in detail in this course as already mentioned defaulting condition we have in the Netherlands is not yet achieved worldwide in fact waterborne diseases are a major killer we have to realize that worldwide every hour about 200 people mainly children lose their life because of these waterborne diseases this make about 200 million people per year these numbers were collected by the World Health Organization in the year 2000 when the Millennium Development Goals or MDG were approved the number speaks for themselves about 1 billion people do not have access to safe drinking water which is particularly a problem in developing countries in Africa Asia and Latin America and note that about 2.4 billion people do not have access to sanitation again the major hurdle has to be taken in developing countries but word is MDG agreements effective on this well no in fact with regard to the sanitation this situation aggravated and now some 2.6 million people have no access to proper sanitation ashame the reason for this incredible backlog are multiple and quite complex and go beyond affect the scope of discourse in industrialized countries we have a full legislative and institutionalized backup to protect our environment and prevent non control discharges this leads to strict control and implementation of the laws also the already mentioned polluter pay principle is widely adopted so industries and individuals actually pay for the required treatment moreover public perception here is strongly in favor of implemented protection although we realize that this cost money how different is the situation in developing countries although many countries have similar restrictive laws as the industrial countries there is literally institutional backup and very little control and implementation in addition cars recovery is hardly implemented so there's an extreme lack of an two resources but needs a high as the scarcely available freshwater resources are more and more threatened now we realize the discourse will not serve the war problems on waterborne diseases but we do want to freely distribute our knowledge on sewage treatment so that anybody interested can take his or her advantage of it

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