A new domestic wastewater management concept: Ecological Sanitation ECOSAN

Son yıllarda gündeme gelen ve ekolojik evsel atıksu yönetimini benimseyen ECOSAN (Ecological Sanitation) yaklaşımına göre evsel atıksu bir kirletici değil yeniden değerlendirilerek kullanılabilecek bir kaynaktır. Bu yaklaşımda ayrıca, kaynakta kontrol ve nütrient döngülerinin tamamlanması gibi konular ön plana çıkmaktadır. Buna göre, evsel atıksuların kaynağında fraksiyonlara ayrılarak toplanması ve her bir fraksiyonun özelliklerine uygun olan bir dizi işlemden geçirilerek tekrar kullanımda değerlendirilmesi önerilmektedir. Bu çerçevede, sarı su (yellow water), kahverengi su (brown water) ve gri su (grey water) şeklinde fraksiyonlar tanımlanmaktadır. Tuvalet haricindeki sulardan oluşan ve en çok organik madde yönünden zengin olan gri su, bu fraksiyonlardan en az kirletici özelliğe sahiptir ve bu akımın gerekli arıtımdan sonra sulama ve yeraltı suyu beslemesi gibi yollarla su döngüsüne geri verilmesi önerilmektedir. Kaynakta ayrılarak toplanmış insan idrarından oluşan ve evsel atıksuların  içindeki azotun % 90’a yakın bir kısmı ile fosfor ve potasyumun da yaklaşık yarısını içeren sarı suyun tarımda gübre olarak kullanımı, organik madde, potasyum ve patojenik mikroorganizma yönünden zengin olan ve esasen ayrı toplanmış insan dışkısından oluşan kahverengi sudan ise bir dizi işlemden sonra biyogaz üretiminde ya da toprak şartlandırıcısı olarak yararlanılması öngörülmektedir. Kavramsal çalışmaların Almanya ve İsveç’te, uygulamaların ise Asya ve Afrika ülkelerinde daha yaygın olduğu izlenen ECOSAN’la ilgili olarak ülkemizde de çalışmalar başlatılmıştır. Bir arıtma teknolojisinden ziyade evsel atıksu yönetim yaklaşımı olan ECOSAN, hem altyapı hem de arıtma / işleme yönünden konvansiyonel yaklaşıma göre önemli farklılıklar göstermektedir. 2000’li yılların konsepti olan ECOSAN gerek araştırma gerek uygulama açısından çok açık bir alan sunmaktadır. Anahtar kelimeler: ECOSAN, ekolojik evsel atıksu yönetimi, altyapı ve arıtma, evsel atıksu fraksiyonları, geri kazanım ve tekrar kullanım, kaynakta ayırma.The emerging sanitation and wastewater management concept of the recent years Ecological Sanitation (ECOSAN) claims that domestic wastewater is not a waste to be discarded but a source to be revaluated. Within that context, various domestic wastewater fractions are separated at their source of origin, collected, stored and processed as necessary as different streams. Basically three fractions are defined: grey water, yellow water and brown water. A very important advocation of ECOSAN is the closing of material loops, especially those for the nutrients. Grey water which is all but toilet wastewater, constitutes about three fourths of conventional domestic wastewater and is the fraction which is the weakest among the three in terms of pollution potential. As such, its final reuse in the water cycle is suggested. The use of processed grey water as irrigational water or as a source for groundwater recharge is recommended after treatment mainly to provide organic matter removal in various biological treatment systems. Yellow water consists of source separated urine at its origin. This fraction is rich in terms of nutrients and contains nearly 90 % of the nitrogen and over 50 % each of phosphorus and potassium in domestic wastewater. As such, its use in agriculture as fertilizer is recommended after storage for hygienic reasons. Storage periods of up to six months are recommended for the complete destruction of pathogens. During storage characteristics of urine change significantly, especially in terms of the form of nitrogen, as urea is converted into ammonium, and in terms of salinity. Work undertaken in the field of processing and reuse of yellow water has mainly concentrated on the direct application of urine onto agricultural fields. The results from such efforts have given results comparable to synthetic fertilizers from the point of view of crop production; however the need for further research regarding the possible fate of pharmaceuticals and hormones from urine together with the issue on salinity has also been brought to attention. A group of work, although more limited in number, has also been presented in the literature directed towards the indirect use of urine for agricultural purposes, for example upon processing with the natural zeolite clinoptilolite or struvite precipitation. Brown water on the other hand is mainly separately collected human feces at its origin. This stream contains the majority of pathogenic microorganisms, nearly half of each of organic matter and potassium in domestic wastewater. The use of brown water for biogas production upon anaerobic digestion or as soil conditioner after composting is suggested. Clearly, the practice of ECOSAN at the large scale as a new means of domestic wastewater management necessitates the installation and construction of relevant infrastructure which will be considerably different form their conventional counterparts, like toilets which can separate yellow and brown water fractions, and processing units together with storage facilities. Guidelines and limits regarding the reuse of domestic wastewater fractions are extremely limited at this time, and the existing ones given by the World Health Organization are directed towards the deactivation of pathogenic microorganisms and the routes of application of the urine onto agricultural fields. Setting of limits and guidelines in terms of concentrations of constituents is a very significant issue which is yet to be handled. The majority of the work devoted to the subject matter in terms of conceptual research seems to be generated mostly in Germany and Sweden, while the majority of practical applications are conducted mostly in Asian and African countries. Although limited in number, ECOSAN related research is also on the way in Turkey as well, and most of those efforts are directed towards alternatives devoted to the indirect use of urine in agriculture together with alternatives related to the treatment of grey water. ECOSAN seems to be one of the developing concepts of the future and ECOSAN related research is one of the open areas in environmental engineering, as well as in terms of practice and practical applications. Keywords: ECOSAN (Ecological Sanitation), domestic wastewater management, infrastructure and treatment, domestic wastewater fractions, recovery and reuse, source separation

Mevsimsel nüfus değişiklikleri ve atıksu yönetimi üzerine bir inceleme

One of the most critical issues in terms of management of touristic areas is the variability of population throughout the year. The population increase during the peak season due to tourism imposes a stress on water resources and leads to pollution risks in the coastal areas. Coastal tourism is widely regarded as one of the fastest growing areas of the world?s tourism industry. All over the world, coastal areas are developing rapidly and are attracting more and more tourists each year. The Mediterranean is the main tourist destination in the world. The main problems of Mediterranean destinations are the seasonal and coastal concentration of tourism activities. Every year more than 250 millions of people flock to the Mediterranean coasts. Additionally, second housing increases the population during the peak season.  This increase in population brings about a peak in water demand for domestic use. Tourism activity peaks in summer, coinciding with the time when natural water availability is at its lowest. According to European Environmental Agency (EEA, 2000), tourists consume up to 300 litres (up to 880 litres for luxury tourism) and as apposed to a use of 150-250 litres of water per person per day by a regular user. Extensive landscaping, water parks, swimming pools and golf courses are typical tourist facilities that require water during the dry season. Taking the example of Bodrum, a touristic summer town in the Eastern Mediterranean region, the top reasons for preference were reported to be the sea, the sun, the beaches, its natural beauty and cultural heritage. In this case study, the resident population of the Bodrum peninsula is 118237 and this is regularly and officially recorded. However vast increases in population are observed during the peak season due to national and international tourists and second housing in the area in addition to the busy pleasure craft traffic. No doubt, knowing the correct number people in town throughout the year is one of the prerequisites of water and wastewater management. However no information about second housing and tourism population seems to be officially recorded. This work focuses mainly on the prediction of the variations in the total population of Bodrum throughout the year. Predictions were based on an investigation to quantify the monthly percentages of resident, second housing, touristic and pleasure craft populations, based on currently available data to lead to a relevant wastewater management approach and an evaluation of its implications on wastewater management. The predictions have indicated that dominated by the tourists and second housing in July and August, the population is more than fourfold of that of February. As a result of the vast seasonal variations in population together with the topographical conditions of the peninsula, wastewater disposal of in Bodrum consists of central facilities and a large number of individual biological treatment systems serving second housing sites, hotels and marinas. Treated effluent is reused for irrigation of gardens in these areas. Holding tanks, which are widely used throughout the peninsula, also provide an alternative to individual biological treatment plants. Despite the quality of reclaimed domestic wastewaters is judged by the fecal coliform standard in the Turkish environmental legislation and international guidelines (WHO 89/2006 and USEPA2004), at this time, regulatory agencies allow the use of reclaimed domestic wastewater that has been treated to essentially secondary level followed by disinfection, for landscape purposes, park and golf course irrigation. The reclaimed effluent is monitored for BOI5, COD, pH and SS. but not for pathogenic microorganisms, which may lead to health concerns.The allocation of revenues of the general budget which is determined according to residential population, is the most significant financial source for municipalities. However this allocation does not seem fair for touristic summer towns like Bodrum as the population increase during the peak season is almost four times that of resident population. Environmental protection and pollution prevention is obviously one of the main factors in the sustainability of Bodrum peninsula as a popular and preferred touristic town, as well as other towns of similar character. A thorough recording of its demographical status and a serious well-planned monitoring and control strategy regarding wastewater management and water quality will provide powerful tools towards sustainability of the area. Keywords: Seasonal population, tourism, second housing, wastewater management, Bodrum.Turizm; yerleşimlerin nüfusunu arttıran ve yıl içinde mevsimsel nüfus hareketliliklerine neden olan bir aktivite olup, özellikle Akdeniz kıyılarındaki birçok yerleşimin ekonomisinde belirleyici olmaktadır. Mevsimsel nüfus hareketlilikleri de daha çok kıyı turizmi yapılan bölgelerde görülmekte, yerleşik nüfusla birlikte ikinci konut nüfusu, turizm nüfusu ve günübirlik nüfusun toplamından oluşan yaz nüfusu, kış nüfusunun birkaç katına çıkmaktadır. Turizmin neden olduğu mevsimsel nüfus hareketlilikleri özellikle atıksu yönetimi açısından önemli problemler oluşturmaktadır. Yerleşik nüfus göz önüne alınarak yapılan tesisler yaz aylarında yetersiz kalmaktadır. Bodrum Yarımadası son 30 yılda dünyanın önemli turizm merkezlerinden biri haline gelmiştir. Yarımada da yerleşik nüfus ile ilgili kayıtlı verilere ulaşılabilmekte ancak, ikinci konut ve turizm nüfusuna yönelik sınıflandırılmış veri bulunmamaktadır. Bu çalışmada yapılan kestirimlerde yarımada genelinde toplam nüfusun yerleşik nüfusun 4, ortalama nüfusun da 2 katına çıktığı hesaplanmıştır. Bodrum’da topoğrafik yapı ve mevsimsel nüfus değişiklikleri nedenleriyle merkezi ve bireysel arıtma tesisleri ile foseptikler bir arada kullanılmaktadır. Özellikle bireysel arıtma tesisleri çıkışları sulama amaçlı kullanılmakta olup denize deşarj edilmelerine izin verilmemektedir. Bodrum yarımadasındaki 397 arıtma tesisinin 387’si bireysel arıtma tesisi olup bunların işlevlerini yerine getirdiklerinin dikkatle planlanmış bir izleme denetim mekanizmasıyla takibi halk sağlığı ve sürdürülebilirlik açısından önemlidir. Mevsimsel nüfus hareketliliklerinin belirgin olduğu turizm yörelerinde teknik bakımdan pik nüfusun, finansal bakımdan ortalama nüfusun dikkate alınması uygun görülmektedir.  Anahtar Kelimeler: Mevsimsel nüfus hareketliliği, turizm, ikinci konut, atıksu yönetimi, Bodrum

Çok amaçlı filtrelerde farklı zeolit kullanımları için amonyum ve askıda katı madde giderimi

With increasing quantities of pollutants being discharged into receiving waters over the years, new and more stringent effluent quality standards have been adapted in various countries of the world. In many cases compliance with new standards may be possible by using different systems. The selection of the most beneficial treatment plant scheme will turn  out to be more and more important in the future. Available land for treatment plants are generally limited, therefore it must be used efficiently. For this reason, retention times in reactors, hence reactor volumes should be kept reasonably small to reduce area requirements. In recent years, there are more stringent standards for some parameters, especially for discharging in sensitive areas. Two of these parameters are ammonium and suspended solids which standardizied by European Council directive named "Urban Wastewater Treatment Directive",  (91/271/EEC) which is also adapted  for Turkey. Ammonium is classically removed in biological treatment units through nitrification. This is an effective removal technique when influent ammonium concentration is more or less constant, but in the case of variable and peak loads, the same pattern of fluctuations in the influent may be observed in the effluent stream. This seems to be even a more significant problem for plants at areas in which standards are altered to more stringent ones in time. Classically suspended solids are removed in secondary treatment units, but if high suspended solids removal rate will be needed, filters are used for advanced treatment of suspended solids. This study is aimed to determine the conditions which will give the highest benefits for the simultaneous removal of ammonium and suspended solids in a multi-purpose filter for different zeolite placement types, and zeolite  volume/bed volume ratios at the same filtration rate. In experimental analysis, Bigadiç clinoptilolite which is a natural zeolite from the western Anatolia is used as ion exchanger and sand is used as filtration support material. There are batch tests  and coloumn analysis in laboratory studies. In batch tests, the capacity of Bigadiç clinoptilolite was determined as  10.4 mg/g for 20 mg/lt initial wastewater ammonium concentration at pH 7.3 and 0.5-1 mm diameter zeolite is used. In column analysis, different multi-purpose filters are designed with different zeolite placement types and  zeolite  volume/bed volume ratios, at the same filtration rate. Ammonium and suspended solids removal rates are observed and compared for all multi-purpose systems. The column analysis are  aimed to determine the conditions which will give the highest benefits for the simultaneous removal of ammonium and suspended solids in a multi-purpose filter. Having that purpose, analysis are made in two stages. In both of the stages, systems are operated downflow and 0.5-1 mm zeolite and sand used as filter material. In first stage three different systems are constituted to determine the effects of zeolite placement on ammonium and suspended solids removal; 1- A  multi purpose  filter in which 25% of filter material is zeolite and zeolite is located at the upper layer of the filter bed. 2- A  multi purpose  filter in which 25% of filter material is zeolite and zeolite is located at the bottom layer of the filter bed. 3- A  multi purpose  filter in which 25% of filter material is zeolite and zeolite is mixed with sand through the filter bed. In second stage two different systems are constituted to determine the effects of zeolite quantity on ammonium and suspended solids removal; 1- A multi purpose filter in which 25% of filter material is zeolite and zeolite is located at the upper layer of the filter bed. 2- A multi purpose filter in which 50% of filter material is zeolite and zeolite is located at the upper layer of the filter bed. By the evaluation of experimental analysis,  a multi-purpose filter in which 50% clinoptilolite used as upper layer is recommended  with 100% ammonium removal and 82% suspended solids removal in working period of 120 hours .The success of this investigation could be an alternative both for the upgrading of existing treatment plants or polishing stage for ammonium and with a high removal suspended solids rate by using a multi-purpose filter. Keywords: Multi purpose filter, filtration, ion exchange, suspended solids removal, ammonium removal, clinoptilolite. Son yıllarda özellikle hassas alanlara deşarj konusunda Avrupa Birliği tarafından uygulanan ve Türkiye'de de yürürlükte olan "91/271/EEC" nolu "Kentsel Atıksu Arıtımı Yönetmeliği" ile daha sıkı standartlar getirilen parametrelerden ikisi amonyum ve Askıda Katı Madde (AKM) parametreleridir. Bu çalışmanın amacı, klasik atıksu arıtma sistemleri çıkış sularında önemli bir problem olan amonyum ve askıda katı madde parametrelerini, standartların altına düşürmek için hazırlanan "klinoptilolit+kum" malzemeli çok amaçlı filtrelerde klinoptilolit konum ve miktarının  giderim üzerindeki etkilerinin incelenmesidir. Deneysel çalışma kısmında öncelikle tez kapsamında kullanılan klinoptilolitin amonyum giderim kapasitesi belirlenmiştir. 20 mg/lt amonyum içeren atıksu konsantrasyonunda,  0,5-1 mm dane boyutunda klinoptilolit için pH 7.3'de bu çalışmada kullanılan Bigadiç klinoptilolitinin amonyum tutma kapasitesi 10.4 mg/g olarak bulunmuştur. Sürekli deneylerin ilk aşamasında, çok amaçlı filtre sisteminde zeolit farklı  konumlara yerleştirilerek amonyum ve AKM giderim verimleri belirlenmiştir. Daha sonra aynı  filtrasyon hızında %25 ve %50 oranlarında klinoptilolit içeren iki farklı çok amaçlı filtre sistemi oluşturularak amonyum ve AKM giderim verimleri tespit edilmiştir. Yapılan deneysel çalışmalar sonucunda toplam yatak hacminin %50'si oranında klinoptilolit kullanılan, klinoptilolitin üste yerleştirildiği aşağı akışlı sistem, 120 saatlik işletim süresinde %100 amonyum giderimi ve %82 AKM giderimi sağlamış olduğundan en uygun çok amaçlı filtre sistemi olarak önerilmiştir. Giriş amonyum ve AKM konsantrasyonlarına bağlı olarak pilot çalışmalar ile belirlenecek uygun filtre hızı ve temas süreleri için oluşturulabilecek çok amaçlı filtre sistemleri ile, amonyum ve AKM'nin birlikte giderimi için uygulamada verimli sonuçlar elde edilebileceği düşünülmektedir. Anahtar Kelimeler: Çok amaçlı filtre, filtrasyon, iyon değişitirme, askıda katı madde giderimi, amonyum giderimi,klinoptilolit.&nbsp