Sludge reduction with pulse ozonation

Biyolojik atıksu arıtma tesislerinde atıksuyun arıtılmasının yanı sıra fazla çamurun da uzaklaştırılması önemlidir. Tesis işletme maliyetlerinin yaklaşık yarıdan fazlası çamur bertarafına harcanmaktadır. Bu nedenle uygulanabilir, ekonomik ve yenilikçi yöntemler araştırılmaktadır. Araştırılan süreçler arasında ozon güçlü bir oksidan olarak ön plana çıkmaktadır. Bu çalışmada 15-30 gün gibi uzun süren aerobik çürütmeyi kısaltmak için havalandırmaya ilave olarak ozon kullanılması araştırılmıştır. Benzer çalışmalardan farklı olarak araştırmada ozon sürekli olarak kullanılmamış olup bakterilerin ikileme zamanı dikkate alınarak 24 saatte bir kez pals şeklinde kısa sürelerle tatbik edilmiştir. Böylece ozonun biyolojik parçalanmaya olan etkisi de incelenmiştir. Ankara Tatlar Atıksu Arıtma Tesisi Havalandırma Tankı’ndan alınan numuneler ile yapılan deneyler sırasında günde bir kez erlenlerdeki çamurlara 2, 3, 4 ve 6 dakikalık sürelerle ozonlama yapılmış, daha sonra çamur 24 saat süreyle çalkalayıcıda bekletilmiştir. Dört gün süreyle devam eden deneylerde rutin olarak TKM, UKM, KOİ ve OTH  ölçümleri yapılmıştır. Sonuç olarak bu süre bitiminde UKM indirgenmesi 2, 3, 4 ve 6 dakika ozonlamalar için sırasıyla %22.6, %40, %75 ve %84 olarak tespit edilmiştir. Standart havasal çamur çürütme ile elde edilen çamur azaltımı %40-50 iken kesikli ozonlama ile elde edilen çamur azaltımı % 80 üzerine çıkmıştır. Yine reaksiyon süresi 20-30 günden 4 günlere inmiştir. Ozon destekli çürütülmüş çamurda yapılan koli basili analizleri de çamurdaki koli basillerinin bu süre içersinde tamamen öldürüldüğünü göstermiştir. Yine ozon destekli havasal çürütmede önemli mitarda ortama fosfor salınmadığı görülmüştür. Anahtar Kelimeler: Ozon, çamur degredasyonu, bakteri, ikileme zamanı, pals.Biological treatment is one of the most widely used treatment techniques. Although its high efficiency and easy design make it a preferable option, excess sludge production is a massive burden for the facilities. Approximately, half of the operation cost for domestic wastewater treatment plants is spent for sludge treatment and disposal. Even after treatment it may act as a secondary pollution source at the disposal site due to its heavy metal, pathogen and persistent organic pollutant contents. Therefore, several strategies are considered for excess sludge treatment. Incineration, dewatering, landfilling and use for agricultural purposes are some of them. However, since regulations on the use and disposal of excess sludge are much more stringent than past years, people tend to use methods which reduce the volume of sludge such as thermal, mechanical, chemical and oxidation pretreatment. Ozonation which is a chemical treatment method establishes disintegration by two mechanisms: first one is the destruction of the cell wall of the microorganism and the second one is the mineralization of the intracellular components. According to high degree of disintegration and cost effectiveness of ozonation make it a feasible technique among the other disintegration techniques. Consequently, ozone treatment of sludge gaining popularity and this leads to a new area of study in environmental engineering. The common point of previous studies is the continuous ozonation of the samples. However, ozone is a very expensive chemical to be wasted. Therefore it should be used properly. That led us to consider about pulse ozonation of sludge which would be economically more feasible if it can be as efficient as continuous ozonation. In this study it was planned to use ozone as a substitute to shorten the 15-30 day-long aerobic digestion process. Waste activated sludge samples from Ankara Tatlar Wastewater Treatment Plant were ozonated for 2, 3, 4 and 6 minutes respectively in Erlenmeyer flasks once a day on each of four consecutive days and left for incubation in between on a shaker. In the experiments, ozone was supplied by OSC-Modular 4HC, WEDECO ITT INDUSTRIES (2007) ozone generator. Operating pressure of the generator is 5 bar and the gas flow rate is 10-140 L/hr with a rated capacity of 4 g/hr. Ozone amount that is released to water in time interval was measured by using Standard Methods 8021 (DPD chlorine reagent) and calibration curve was obtained by spectrophoto-metric measurement (for 25 mL sample). The MLVSS, MLSS, COD and OUR parameters were measured routinely during the four days. MLSS measurements were done according to Standard Methods (2540B) (APHA, 1998). Chemical oxygen demand (COD) was measured by Hach Lange kits according to HACH 8000(US EPA approved) method. Volatile Suspended Solids (MLVSS) was measured according to 2540 solids method. Total-P was analyzed by 365.4 EPA Method and ortho-phosphate was analysed with 365.3 EPA Method. Obviously, one of the most important reasons of sludge treatment is sludge disinfection. In order to have an opinion about this concept, it was decided to count E.coli in the sludge. Also considering the possibility of phosphorus release, total phosphorus and ortho-phosphate were checked in the 6' ozonated sample. At the first day, total phosphorus of the sludge was 0.006 g per g biomass and after the first ozonation this amount increased to 0.0082. By these results, it can be concluded that ozonation does not release significant amounts of phosphorus to the medium. At the end of the experiments, MLVSS reductions for 2, 3, 4, and 6 minutes were observed as 22.6%, 40%, 75% and 84% respectively. As a result of the experiments, by the pulse ozonation of the non-digested activated sludge, both stabilization and reduction of the sludge were achieved in such short period as 4 days. Moreover, it can be ascertained that the obtained sludge was both disinfected from E.coli and phosphorus rich. Furthermore, since the COD left in the medium after the experiments was biodegradable, it was concluded that it would be feasible to return to the beginning of the system.  Hence, it became possible to save on both time of contact and the amount of ozone used in comparison with other studies where samples were ozonated on continuous bases. The obtained results show similar values for MLVSS, MLSS and COD for both 4' and 6' ozonation for first 3 days. Nevertheless, since the 6' ozonation is more effective in sludge stabilization, after the 4' ozonation for the first 3 days, 6' ozonation for the 4th day is suggested. Keywords: Ozone, sludge degradation, bacteria, doubling time, pulse

Levodopa-refractory hyperprolactinemia and pituitary findings in inherited disorders of biogenic amine metabolism

Elevated serum prolactin concentrations occur in inherited disorders of biogenic amine metabolism because dopamine deficiency leads to insufficient inhibition of prolactin secretion. This work from the International Working Group on Neurotransmitter Related Disorders (iNTD) presents the results of the first standardized study on levodopa-refractory hyperprolactinemia (LRHP; >1000 mU/L) and pituitary magnetic resonance imaging (MRI) abnormalities in patients with inherited disorders of biogenic amine metabolism. Twenty-six individuals had LRHP or abnormal pituitary findings on MRI. Tetrahydrobiopterin deficiencies were the most common diagnoses (n = 22). The median age at diagnosis of LRHP was 16 years (range: 2.5-30, 1st-3rd quartiles: 12.25-17 years). Twelve individuals (nine females) had symptoms attributed to hyperprolactinemia: menstruation-related abnormalities (n = 7), pubertal delay or arrest (n = 5), galactorrhea (n = 3), and decreased sexual functions (n = 2). MRI of the pituitary gland was obtained in 21 individuals; six had heterogeneity/hyperplasia of the gland, five had adenoma, and 10 had normal findings. Eleven individuals were treated with the dopamine agonist cabergoline, ameliorating the hyperprolactinemia-related symptoms in all those assessed. Routine monitoring of these symptoms together with prolactin concentrations, especially after the first decade of life, should be taken into consideration during follow-up evaluations. The potential of slow-release levodopa formulations and low-dose dopamine agonists as part of first-line therapy in the prevention and treatment of hyperprolactinemia should be investigated further in animal studies and human trials. This work adds hyperprolactinemia-related findings to the current knowledge of the phenotypic spectrum of inherited disorders of biogenic amine metabolism

Occipital epilepsies in children

PubMed ID: 12374578Occipital lobe seizures, as defined by subjective symptoms and objective signs, can be recognized by clinical seizure characteristics in most cases. Visual symptoms such as hallucinations and amaurosis are the most common occipital lobe seizure symptoms. The patients must be classified in order to be able to define the prognosis. In this study, we classified patients with occipital epilepsy as childhood epilepsy with occipital paroxysms (19 patients), idiopathic photosensitive occipital epilepsy (10 patients) and symptomatic occipital epilepsy (25 patients). They were evaluated according to clinical, electrographic and neuroimaging characteristics

Primary Sjögren's Syndrome Presenting As Neuromyelitis Optica

PubMed ID: 17162200This report presents a patient with Devic's neuromyelitis optica associated with primary Sjögren's syndrome. Her first attack was right-sided optic neuritis at age 10 years. Attacks involving both optic nerves and medulla spinalis were recorded during the ensuing years. The diagnosis of Sjögren's syndrome could not be made until the second decade because it was not suspected. © 2007 Elsevier Inc. All rights reserved

Childhood-onset optic neuritis as the first manifestation of Behçet's disease

A 15-year-old girl presented with sudden blurring of vision in both eyes, which was recurring for the third time. The fundoscopy demonstrated bilateral optic disc edema with macular star exudates. The diagnosis of Behçet's disease (BD) could be made 5 months after the first visual disturbance, when the other manifestations of the disease occurred. Although ocular involvement is frequent, primer optic neuritis has rarely been reported in BD. Childhood onset of the disorder is very uncommon as well. To our knowledge, this is the first report of optic neuritis as the first manifestation of BD in the pediatric age group. Copyright © Taylor & Francis Group, LLC

POEMS syndrome: Case report [POEMS sendromu: Olgu sunumu]

Presented with characteristic polyneuropathy and multisystemic manifestations, POEMS syndrome is a rare plasma cell disorder. Vascular endothelial growth factor, secreted by plasmacytoma, is considered responsible for these symptoms. The first symptoms in this patient were arthralgia, distal sensory impairment ascending proximally and motor impairment of distal lower extremities. By immunoelectrophoresis, M protein in serum and urine was detected. In addition to polyneuropathy and monoclonal gammopathy, the patient presented with organomegaly, endocrine dysfunction and skin changes, and was diagnosed as POEMS syndrome. This rare syndrome should be included in the differential diagnosis of acquired neuropathies associated with multisystemic manifestations

Headache in primary Sjögren's syndrome: A prevalence study

PubMed ID: 18355394Objectives - To determine the prevalence of headache in patients with primary Sjögren's syndrome (pSS) and to examine the relationship between headache types and clinical, serologic features of the disease. Methods - The study enclosed 133 patients with the diagnoses of pSS and 97 healthy controls. A questionnaire designed to assess the presence of headache and if present to classify it according to the criteria of the International Headache Society was used. Results - In 133 of the pSS patients evaluated, 104 had headache. No association was present between types of headache and the clinical and laboratory manifestations of the disease. Both migraine and tension-type headache were more common in patients with pSS when compared with healthy controls (P < 0.001). Conclusions - The high prevalence of migraine in pSS patients might be explained by a vascular headache triggered by immuno-mediated disease activity without an obvious clinic or laboratory marker. Copyright © 2008 The Authors

Multimodal evoked potentials in primary Sjögren's syndrome without neurological manifestations

We evaluated multimodal evoked potentials in patients with primary Sjögren's syndrome without clinical neurological manifestations. While brainstem auditory evoked potentials (BAEP) were performed in ninety patients visual (VEP) and somatosensory evoked potentials (SEP) could be evaluated in fifty-eight patients. The control group included 20 healthy adults matched for sex and chronological age. VEP and AEP studies did not reveal any abnormality. In SEP; N9-N13 interpeak latencies were significantly prolonged in the patients group. However, the latency of N9 potentials recorded from Erb's point was normal as well as the N13-N20 interpeak latencies. This result indicates that central branches of the primary sensory neurons are involved in Sjögren's syndrome

Kluyveromyces türü mayalarda metal dirençliliği, metal biyosorpsiyonu ve metal-bağlama proteinlerinin tanımlanmasına ilişkin çalışmalar

TÜBİTAK TBAG01.09.1993Saccharomyces cerevisiae'nin Cupl bir susu ile karşılaştırıldığında, Kluyveromyces türlerinin toksik ağır metallere çok daha fazla dirençli oldukları bulunmuştur. Metallotiyonin sentezinin S. cerevisiae'da bakır ve gümüş ile indüklenmesine karşın K. marxianus'da konstitütif olduğu görülmüştür Ayrıca, gümüş ve kadmiyum ile muamele edildiğinde, K. marxianus• 'da metallotiyoninden daha küçük molekül ağırlıkta bir diğer proteinin.sentezlendiği bulunmuştur. K marxianus tarafından en hızlı ve en fazla biriktirilen metal gümüştür; bu metalin % 90'ı ilk 6 saat içinde hücreler tarafından bağlanmıştır. Bu organizmada bakır ve kadmiyum biyosorpsiyonu da oldukça yüksek olup. 14 saatlik bir süre içerisinde sırasıyla % 60 ve % 65'lik etkinliklerle gerçekleşmiştir. Kobalt, çinko ve mangan akümülasyonu her iki organizmada da oldukça düşük seviyelerdedir. Metallerin sadece çok küçük miktarlarının çözünür sitoplazma içinde olduğu , hücreler tarafından yüksek seviyede biriktirilen metallerin hücre duvarına ve vakuollere bağlandığı gösterıiMıiştir. K. marxianus'un altın iyonlarının solüsyonlardan geri kazanunında etkin bir şekilde kullanılabileceği de yine bu çalışmada gösterilmiştir