No abstract

In this study, it is aimed to determine and map the noise pollution levels in Safranbolu District Center, especially in the regions where motor vehicle and/or pedestrian traffic is intense. Forty-seven measurement points were selected for noise level measurements at the district center. Measurements were conducted at morning (8 a.m.–10 a.m.), lunchtime (12 p.m.–2 p.m.) and evening (6 p.m.–8 p.m.) hours of weekdays and weekends throughout the seasons of summer 2017 and winter 2018. The summer season weekdays noise level ranges from 41.3 to 71.2 dBA in the morning period, 40 to 71.2 dBA in the noon period and 40.6 to 73.1 dBA in the evening. The summer season weekend noise level ranges from 45.3 to 69.1 dBA in the morning period, 44.7 to 71.4 dBA in the noon period and 41.6 to 70.9 dBA in the evening. The result showed that the level of summer season weekday and weekend noise pollution in the morning, noon and evening is close to each other. In addition, the winter season weekdays noise level ranges from 32.3 to 68.5 dBA in the morning period, 30.8 to 73.3 dBA in the noon period and 37.4 to 72.9 dBA in the evening. The winter season weekend noise level ranges from 37.2 to 65.8 dBA in the morning period, 40 to 71.3 dBA in the noon period and 40.5 to 69.7 dBA in the evening. The result showed that the level of winter season weekdays and weekend noise pollution in the noon is generally higher than morning and evening. The obtained data are compared with the limit values specified in the Environmental Hazard Assessment and Management Regulation. The hazardous noise level, which is considered as the threshold for causing physiological problems on humans, was determined to be exceeded at many locations. This situation may cause significant negative consequences on human health, quality of life and tourism sector. Obtained data were processed, and noise pollution levels for the city of Safranbolu were mapped using a geostatistical analysis software. In total, 16 noise pollution maps were drawn for different situations (e.g., weekdays, weekend, daytime, noon, night, summer season, winter season, etc.). Obtained noise level results demonstrate that the overall quality of the acoustic environment in our study area was medium level, which means that exposure to these levels over a long period can affect human health and quality of life. Finally, the results of a survey conducted as a part of this study were given, and possible measures and suggestions to reduce these noise levels in the district down to the desired limit values were discussed. Supplementary Information The online version contains supplementary material available at 10.1007/s10668-021-01303-5.

No abstract

Öz Günümüzün en önemli teknolojilerinden biri olan nanoteknolojideki gelişmeler her alanda olduğu gibi çevre alanında da kullanım şekillerini arttırmaya başlamıştır. Bu teknoloji düşük maliyetli, çevre dostu alternatif malzeme üretiminde kullanılabildiği gibi aynı zamanda hem mevcut kaynaklarımızı korumada ve kirleticilerin tutulması, arıtımında da kullanılabilmektedir. Bu bağlamda bu çalışma nanopartiküllerin çevre mühendisliğinde kullanım alanları ve temel laboratuvar malzemeleri ile gümüş nanopartikül sentezi hakkında hazırlanmıştır. Çalışmanın sentez bölümünde elde edilen nano gümüş çözeltisi, sodyum borhidrür (NaBH₄) kullanılarak gümüş tuzunun (AgNO₃) indirgenmesi ile kimyasal yöntem ile oluşturulmuştur. Oluşturulan ürün Taramalı Elektron Mikroskobu (SEM) ve UV-VIS spektrometre ile karakterize edilmiş ve boyut analizi gerçekleştirilmiştir. Elde edilen nanopartikül boyutlarının yaklaşık 70 nm ~ 77 nm arasında olduğu gözlemlenmiştir. Ayrıca gümüş nano partiküllerin adsorpsiyon seviyesinin 350 ~450 nm aralığında ve 396,016 nm olduğu bulunmuştur.

Sanitary landfill is the most preferred municipal solid waste disposal method. The production of highly polluted leachate is a major disadvantage of sanitary landfills. In this study, optimization of struvite precipitation to remove ammonium from landfill leachate was conducted by using Response Surface Methodology and central composite design. Optimum struvite precipitation conditions were determined based upon 11 runs performed in central composite design. A second-order polynomial functional model was fitted well to the results. The statistical analysis showed that two independent variables which are molar rates of Mg/N and N/P had significant effects on the ammonium removal efficiency. Maximum ammonium removal efficiency was 99.8% at a molar rate of 1.20 for Mg/N and 1.27 for N/P for a constant 9.2 pH value. The obtained results revealed that struvite used as pre-treatment in anaerobic process can be modelled by using response surface methodology. And also, response surface methodology can be used to optimize required ammonium removal efficiency for lower Mg/N and N/P molar ratio which affects the performance of pre-treatment method that designed for an anaerobic process having 300:5:1 ratio for COD/N/P.