The recent statistics show that the world's population is rapidly increasing. This increase negatively afects the water resources and it increases the water demand progressively.Along with the increase in the world's population, the insensible use of water resources, pollution, and drought lead to the increasing reduction of water resources. Due to these factors, all countries, primarily developed countries, have started looking for new water resources. This search has been extended to extraterrestrial water. However, the existing technology and opportunities direct countries toward the puriication of wastewater rather than searching for new water resources. For the reasons outlined above, puriication and recycling of wastewater become important. In addition to the natural resistance of microorganisms against antibiotics, a resistance also arises because of the unconscious and overuse of antibiotics. This resistance spreads through wastewater progressively. Antibiotic resistance shows an increase according to the scientiic data. In order to prevent the resistance, it is of capital importance to treat the wastewater in which the domestic pollution burden is high. In this study, the role of domestic wastewater in the occurrence and spread of antibiotic resistance will be revealed.

Purpose Stabilization of weak soil can be achieved through different methods, some of which include jet column, cement stabilization and fly ash stabilization. Unfortunately, the use of the aforementioned methods of soil improvement affects the environment negatively thereby leading to environmental degradation. With the aforesaid impediment in mind, the need for devising methods of weak soil improvement becomes pertinent. Methods Bacillus sp. — a non-pathogenic organism found abundantly in soil — was investigated in this study as a potential agent of soil improvement. The usability of Bacillus sp. in soil improvement was investigated with direct shear tests and permeability tests under optimum conditions in this study. Result Time-dependent study on the effect of the ureolytic bacteria Bacillus sp.-induced calcium carbonate precipitation shows reduction in permeability and increase in the strength of the soil under study. On exhaustion of the available nutrients in the soil, however, the strength of the soil is not negatively impacted. Conclusion Microbially induced calcium precipitation by Bacillus sp. is effective in soil improvement as such it may serve as substitute for conventional soil stabilization techniques. The ability of the bacteria to precipitate calcium carbonate in the soil leads to reduction in the permeability and increase in the shear strength of the soil.

Purpose: Stabilization of weak soil can be achieved through different methods, some of which include: jet column, cement stabilization and fly ash stabilization. Unfortunately, the use of the aforementioned methods of soil improvement affects the environment negatively thereby leading to environmental degradation. With the aforesaid impediment in mind, the need for devising methods of weak soil improvement becomes pertinent. Methods: Bacillus sp. - a non-pathogenic organism found abundantly in soil - was investigated in this study as a potential agent of soil improvement. The usability of Bacillus sp. in soil improvement was investigated with direct shear tests and permeability tests under optimum conditions in this study.Result: Time-dependent study on the effect of the ureolytic bacteria Bacillus simplex induced calcium carbonate precipitation shows reduction in permeability and increase in the strength of the soil under study. On exhaustion of the available nutrients in the soil however, the strength of the soil is not negatively impacted.Conclusion: Microbially induced calcium precipitation by Bacillus sp. is effective in soil improvement as such it may serve as substitute for conventional soil stabilisation techniques. The ability of the bacteria to precipitate calcium carbonate in the soil leads to reduction in the permeability and increase in the shear strength of the soil.

Son yıllarda, özellikle büyük kentlerde artan nüfusa bağlı olarak arazi kullanımı git gide artmaktadır. Bu durumda, temel zemini bakımından yeterli kriterli sağlayan arazilerin kullanımının yanı sıra bu kriterleri sağlamayan arazilerin kullanımını da zorunlu hale getirmiştir. Temel zemini bakımından yeterli kriterleri sağlamayan arazilerde, kireç, uçucu kül, yüksek fırın cürufu gibi katkılarla zemin iyileştirme yapılarak istenilen kriterlere ulaşılmaktadır. Ancak bu katkılar doğada CO2 salınımını artırdığı için çevre dostu değillerdir. Bu nedenle, bu katkıların yerini yeni nesil çevre dostu zemin iyileştirme katkıları almaktadır. Bu katkılardan bir tanesi enjekte edildiği zemin içerisinde CaCO3 üreterek iyileşme sağlayan Bacillus Sp.'dir. Bu bağlamda çalışma kapsamında, yüksek plastisiteli kil (CH) ve kumlu kil (SC) türü iki farklı zemin türünde yeni nesil iyileştirme katkısı olan Bacillus Sp. kullanılarak, donma çözülme döngüleri altında mukavemet ve şişme basıncı davranışları araştırılmıştır. Sonuçlara göre, Bacillus Sp.'nin CH ve SC türü zeminlerde, mukavemet ve şişme basıncı parametrelerinin iyileştirilmesinde olumlu yönde katkısı olduğu belirlenmiştir.

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