Field scale evaluation of volatile organic compound production inside biosecure swine mortality composts

Emergency mortality composting associated with a disease outbreak has special requirements to reduce the risks of pathogen survival and disease transmission. The most important requirements are to cover mortalities with biosecure barriers and avoid turning compost piles until the pathogens are inactivated. Temperature is the most commonly used parameter for assessing success of a biosecure composting process, but a decline in compost core temperature does not necessarily signify completion of the degradation process. In this study, gas concentrations of volatile organic compounds (VOCs) produced inside biosecure swine mortality composting units filled with six different cover/plant materials were monitored to test the state and completion of the process. Among the 55 compounds identified, dimethyl disulfide, dimethyl trisulfide, and pyrimidine were found to be marker compounds of the process. Temperature at the end of eight weeks was not found as an indicator of swine carcass degradation. However, gas concentrations of the marker compounds at the end of eight weeks were found to be related to carcass degradation. The highest gas concentrations of the marker compounds were measured for the test units with the lowest degradation (highest respiration rates). Dimethyl disulfide was found to be the most robust marker compound as it was detected from all composting units in the eighth week of the trial. Concentration of dimethyl disulfide decreased from a range of 290–4340 ppmv to 6–160 ppbv. Dimethyl trisulfide concentrations decreased to a range of below detection limit to 430 ppbv while pyrimidine concentrations decreased to a range of below detection limit to 13 ppbv.     

Evaluation of the relationship of picoplankton and viruses to environmental variables in a lagoon system (Çakalburnu Lagoon,Turkey)

Lagoons are defined as wetlands separated from the sea coasts on which they are located and sit between continental and marine aquatic ecosystems. Çakalburnu Lagoon is a coastal wetland on the southern side of the Bay of ?zmir. Microorganisms, which are quite sensitive to changes occurring in environmental factors, are commonly used to determine the impact of environmental effects on the functioning of the ecosystem. In this study, variations in the abundance and biomass of picoplankton (Synechococcus spp. and bacteria) and the abundance of viruses, which identify the ecological productivity of the food chain, were seasonally examined by epifluorescence microscopy. Moreover, the microbial abundance and biomass relation over time between the physical and chemical parameters was evaluated. According to our results, the maximum abundance of Synechococcus spp. and viruses was 6.7?×?10⁴ cell/ml and 9.9?×?10⁸?cell/ml in the summer, respectively. Otherwise, the highest level of bacteria was measured at 3.6?×?10⁷ cell/ml in the spring. Based on the principal component analysis and Pearson correlation analysis results, we concluded that total suspended solids, Chl-a, particulate organic carbon and particulate organic nitrogen were the major parameters influencing the observed variability of the lagoon system. Overall, to protect and improve the ecological and microbiological quality of aquatic systems such as lagoons, the necessary monitoring and measurement studies should be conducted in these sensitive areas.     

The microbial community in a green turtle nesting beach in the Mediterranean: application of the Biolog EcoPlate approach for beach pollution

Environmental Science and Pollution Research - This study aims to characterize the microbial community and its relationship with heavy metal pollution in the beaches of Sugözü, an...     

The impact of pretreatment and inoculum to substrate ratio on methane potential of organic wastes from various origins

Biochemical methane potentials (BMP) of two different substrates from macroalgae (MA) and market place wastes (MPW) were investigated using anaerobic granulated sludge from food industry with different ratios of substrate to inoculum (S/X). The substrates were used as MA only, MPW only, MA–MPW mixture, pretreated MA, and pretreated MA–MPW mixture. Research involved investigation of the effects of parameters such as temperature (35, 45, and 55 °C), substrate to inoculum ratio (S/X = 0.5, 2.0, 4.0, and 6.0 as g VS_substrate/g VS_inoculum), and the type of pretreatment (by microwave, thermal, and ultrasonic) on BMP. BMP assays were performed for all substrates. The highest cumulative biogas production (and BMP) were obtained for MA only at an S/X ratio of 4.0 g VS/g VS as 357 L_biogas/kg VS (197 L CH₄/kg VS) and 33 L_biogas/kg VS (17 L CH₄/kg VS), respectively, at 35 and 55 °C. For pretreated substrates, the highest cumulative biogas production and BMP were observed as 287 L_biogas/kg VS and 146 L CH₄/kg VS using pretreated macroalgae at 35 °C. Results suggested that MA only and MA–MPW mixtures are suitable substrates for biogas production. It is also concluded that any type of pretreatment has adverse effects on biogas and methane productions.     

Disasters as an ideological strategy for governing neoliberal urban transformation in Turkey: insights from Izmir/Kadifekale

Since the turn of the twenty‐first century, Turkish cities have undergone large‐scale change through a process referred to as urban transformation, involving, notably, the demolition of inner‐city low‐income settlements. The official authorities and business circles have resorted to various forms of discourse to justify these projects, which have led to the deportation of a significant number of people to peripheral areas. The discourse of ‘natural disasters’, for example, suggests that urban transformation is necessary to protect people from some pending event. Probably the most effective application of this discourse has occurred in Izmir, where the risk posed by ‘landslides’ has played a critical role in the settlement demolitions conducted in the huge inner‐city neighbourhood of Kadifekale. By examining the case of Kadifekale, this paper provide some insights into how ‘natural disasters’ serve as a discourse with which to legitimise the neoliberal logic entrenched in the urban transformation process in Turkey.     

Full-scale biofilter reduction efficiencies assessed using portable 24-hour sampling units

Portable 24-hr sampling units were used to collect air samples from eight biofilters on four animal feeding operations. The biofilters were located on a dairy, a swine nursery, and two swine finishing farms. Biofilter media characteristics (age, porosity, density, particle size, water absorption capacity, pressure drop) and ammonia (NH3), hydrogen sulfide (H2S), sulfur dioxide (SO2), methane (CH4), and nitrous oxide (N2O) reduction efficiencies of the biofilters were assessed. The deep bed biofilters at the dairy farm, which were in use for a few months, had the most porous media and lowest unit pressure drops. The average media porosity and density were 75% and 180 kg/m3, respectively. Reduction efficiencies of H2S and NH3 (biofilter 1: 64% NH3, 76% H2S; biofilter 2: 53% NH3, 85% H2S) were close to those reported for pilot-scale biofilters. No N2O production was measured at the dairy farm. The highest H2S, SO2, NH3, and CH4 reduction efficiencies were measured from a flat-bed biofilter at the swine nursery farm. However, the highest N2O generation (29.2%) was also measured from this biofilter. This flat-bed biofilter media was dense and had the lowest porosity. A garden sprinkler was used to add water to this biofilter, which may have filled media pores and caused N2O production under anaerobic conditions. Concentrations of H2S and NH3 were determined using the portable 24-hr sampling units and compared to ones measured with a semicontinuous gas sampling system at one farm. Flat-bed biofilters at the swine finishing farms also produced low amounts of N2O. The N2O production rate of the newer media (2 years old) with higher porosity was lower than that of older media (3 years old) (P = 0.042).