Türk linyitlerinin biyolojik yolla sıvılaştırılması ve gazlaştırılması

TÜBİTAK KTÇAG Proje31.10.1993Linyitlerin yakılmaları sırasında ortaya çıkan hava kirliliğinin önlenebilmesi amacıyla bu araştırmada Ülkemizde geniş rezervlere sahip, yüksek kükürt içerikli ve düşük kalorili linyitlerden olan Elbistan, Çanakkale Çan ve Ankara-Beypazarı linyitlerinin biyolojik olarak çözündürülebilirliği ve daha sonra çözündürülen malzemenin karakterize edilerek yine biyolojik olarak gazlaştırılabilirliği araştırılmıştır. Yapılan deneysel çalışmalar sonucunda özellikle Elbistan linyitlerinin Phanerochaete chrysosporium adlı beyaz çürükcül fungus tarafından sekonder metabolizma ürünü ligninaz enzimleri vasıtasıyla %90 üzerinde depolimerize edilebildiği gösterilmiştir. Çan linyitlerinin de 8N $HNO_3$ ile ön muameleyi takiben bir miktar biyolojik depolimerizasyona yatkın oldukları anlaşılmaktadır. Beypazarı linyitleri ise ön muamele ile dahi biyolojik olarak çözündürülemektedir. Fungus tarafından çözündürülen malzemenin daha sonra anaerobik şartlarda gazlaşt ırı Imas ı. deneylerinde brjinal linyitin kalorifik değerinin yaklaşık % 4.6'sı gaz olarak geri alınmaktadır. Kalitatif olarak yapılan gaz analizlerinden gasifikasyon sırasında çıkan gazın hemen tamamen metandan meydana geldiği ve anaerobik çürütme sırasında asit Üretici mikroorganizmaların etkin olmadıkları anlaşılmaktadır. Kullanılan anaerobik kültürün çözündürülen malzemeye yeterince alıştırılamamış olduğu ve çözündürülen malzemenin çok muhtemelen büyük molekül ağırlıklı oligomerlerden meydana gelmiş olduğu düşünülecek olursa oligomerelerin daha küçük molekül ağırlıklı monomerlere ayrıştırılması ve biyolojik gazifikasyon çalışmalarına devam edilmesinde yarar vardır. Diğer taraftan çözündürülen malzemenin yeniden polimerleştirilmesi ile çevre dostu plastiğe benzer bir malzemenin elde edilebilecegi düşünülmüş ve bu yönde çalışmaların südürülmesi önerilmiştir

Kesikli Ozonlama İle Atık Çamur Minimizasyonu Ve Endokrin Bozucu Madde (ebm) Arıtımının İncelenmesi

Bu projede atıksu arıtma tesislerinden ortaya çıkan atık çamurun kesikli ve ardaşık olarak ozonlanması ve ardından havalandırılması ile birlikte etkin çamur arıtımının sağlanması hedeflenmektedir. Proje kapsamında çeşitli atık çamurlar laboratuvarda ozonla muamele edildikten sonra havalandırılacaktır. Bu işlem dört kez tekrar edildikten sonra çamurun çürütülmesi tamamlanmaktadır. Çamurun çalkalamalı etüvde havalandırılması sırasında belirli aralıklarla alınacak örneklerde MLVSS, MLSS, tot-P, PO4 ve çözünmüş KOİ bakılacaktır. Normalda 20-30 gün sürmesi gereken havasal çürütme işleminin bu suretle 4 gün'e kadar kısaltılması ve %40-50 olması gereken çürütülen çamur miktarının da % 80'lere ulaşması beklenmektedir. Ozonla çamur çürütme sırasında çamurdaki patojenlerin de uzaklaştırılması beklenmektedir. Bu olgu çamurda başlangıçta ve sonuçta Koli basili ölçülerek takip edilecektir. Yine ozon muamelesinin çamur tarafından sorbe edilen Endokrin Bozucu Maddelerin (EBM) de parçalanmasına neden olması beklenmektedir. Bu amaçla çürütme işlemi ve sonunda çamurda seçilmiş EBM'ler ölçülecektir. Atıksularda çok düşük onsantrasyonlarda bulunan EBM'ler özellikle çamura yapışmaları sonucunda burada önemli ölçüde konsantre edilmektedir. Bu nedenle çamurların bertarafı sırasında EBM'lerin de uzaklaştırılması beklenmektedır

Treatment of softwood bleacbery effluents by Penicillium camemberti in anaerobic jars

Penicillium camemberti was found to be very effective in treating softwood pulp bleaching effluents and chlorinated model compounds like PCP, 2-chlorophenol and trichloroacetic acid. This paper examines the ability of Penicillium camemberti to degrade softwood pulping and bleaching effluents in anaerobic jars. Softwood chlorinated pulping and bleaching effluents inoculated with Penicillium camemberti (20 ml in 25-ml universal tubes) were incubated under anaerobic conditions (oxoid anaerobic jars) at 25 degrees C for up to 20 days. Samples were analyzed for adsorbable organic halogens (AOX), color and total organic carbon (TOC) removals and gas chromatograms of the samples were recorded. 61% AOX, 62% TOC and 57% color removal was obtained with mineral salts as nutrient and 2 g/l acetate as carbon source. It was found to be remarkable that TOC removal was extremely increased from 62% to 81% with the nutrient only, and without any carbon source. There was a slight increase in AOX (from 61% to 63%) and slight one in color (from 57% to 52%). The highest efficiencies, 62% AOX, 81% TOC and 59% color removal, were achieved, when Penicillium camemberti has been added without any nutrient and carbon source

Developing fungal reactor for organic chlorine removal from pulping effluents

Organic halides are considered environmentally suspect as some are known to have toxic, mutagenic and carcinogenic effects on the biota. A fungus, which is able to affect close to 60 % AOX, colour and TOC removals from softwood bleachery effluents in batch tests have been isolated and tentatively identified. This fungus was subsequently tested for its ability to degrade PCP, a common preservative used in controlling wood rot. Low agitation speeds preferred by the fungus during batch culturing indicated its tendency towards immobilization on a solid matrix. A continuous upflow packed bed reactor was designed and operated successfully in our laboratory for over one and half year with somewhat higher performances over those obtained in batch tests. Around 80% AOX and 60% colour and TOC removals were observed in this packed-bed reactor treating effluents from a softwood pulp bleachery. The PCP removals, which were tested separately, were also comparable to the AOX removals

Identification of electron acceptor properties of Penicillium camemberti used for effective treatment of chlorinated organic compounds

Two methods described in this paper use respirometric monitoring of the accumulated oxygen uptake rate, following the addition of bleachery effluents to a reactor containing Penicillium camemberti and detection of inorganic chloride removal by a chloride electrode for electron acceptor identification. In the case of respirometric studies, adsorbable organic halogens (AOX) removal was retarded at high acetate concentrations and the metabolism shifted towards aerobic respiration. Contrary to this, aerobic respiration was suppressed at low acetate concentrations and the removal of AOX was enhanced. Inorganic chloride removal detected with a chloride electrode verified these findings too. Cl- ion production paralleling AOX removal supports the hypothesis that organic chlorine acts as electron acceptor for this fungus

Removal of chlorinated organics from pulping effluents by activated sludge process

Combined effluents of a Kraft pulp mill using yearly plants were treated in a lab-scale activated sludge system. Average TOC and AOX removal efficiencies were 83% and 21% respectively. The effect of the operating solids retention time (SRT) on AOX removal was investigated and it was found that highest AOX removal (30%) occurs at longer SRT's. Mass balance on the system revealed that the principal AOX removal mechanism was metabolization at long SRT. About 90% of the AOX removed was metabolized. As SRT was lowered both AOX removal efficiency decreased and AOX removal mechanism changed to removal by wastage of the AOX adsorbed onto the daily wasted biomass. The effect of influent AOX concentration and additional carbon source on microbial activity was investigated by performing batch tests. The presence of additional COD increased the activity, however, the effect of influent AOX concentration was not clear

Degradation of chlorinated compounds by Penicillium camemberti in batch and up-flow column reactors

A Penicillium camemberti strain isolated in this laboratory was studied for its ability to degrade chlorinated compounds including pentachlorophenol (PCP), 2-chlorophenol and trichloroacetic acid. The batch experiments were conducted in shake flasks using PCP as co-substrate resulting in around 56% PCP removal by the fungus. Experiments in shake flasks not containing acetate but Tween 80, produced 86% of PCP and 53% of 2-chlorophenol removals in 21 days. PCP was also fed to a column reactor with an adsorbable organic halogens (AOX) concentration of 63.4 mg/l. On the fourth day of operation, AOX removal was 77%, but this steadily dropped to 18.8% on the 18th day

Modeling off a large-scale wastewater treatment plant for efficient operation

Environmental legislations in the Western world impose stringent effluent quality standards for ultimate protection of the environment. This is also observed in Turkey. The current paper presents efforts made to simulate an existing 0.77 million m(3)/day conventional activated sludge plant located at Ankara, AWTP. The ASM1 model was used for simulation in this study. The model contains numerous stoichiometric and kinetic parameters, some of which need to be determined on case by case bases. The easily degradable COD (SS) was determined by two methods, physical-chemical and respirometric methods, namely. The latter method was deemed unreliable and rejected in the further study. Dynamic simulation with SSSP program predicted effluent COD and MLSS values successfully while overestimating OUR. A complete fit could only be obtained by introducing a dimensionless correction factor (eta(O2)=0.58) to the oxygen term in ASM1

Treatment of chlorinated organics in bleached Kraft mill effluents by activated sludge process

Combined effluents from a bleached Kraft pulp mill using annual plants were treated in a lab-scale activated sludge (AS) system. The effects of operating solids retention time (SRT) and concentration of additional carbon source on AOX removal were investigated. Higher AOX removals (30%) were observed with long SRTs, 99% of which was pure metabolization. As SRT was decreased AOX removal efficiency also decreased (4%) and principal AOX removal mechanism changed to adsorption onto wasted biomass. The AOX removal efficiency was lower (10%) on a 20% decrease in the supplemental carbon source, with no apparent effect on the removal mechanism. (C) 1997 IAWQ. Published by Elsevier Science Ltd