Issue 3

Salinity is a key environmental factor for the successful application of anammox technology in wastewater treatment, because it impacts the activity and the community structure of anammox bacteria. In this study, the changes in activity and population shifts of an anammox system response to the elevated salt stress (0, 5, 10, 20, 30 and 40 g NaCl/L) were studied.

The results show that the anammox reactor performed effectively even at 30 g NaCl/L salinity after an appropriate acclimatization. The nitrogen removal rate maintained at 0.28 g N L-1d-1 with the nitrogen removal efficiency of 76%, though the high environmental salinity might inhibit the anammox growth in the long-term operation. 16S rRNA high-throughput sequencing results revealed that Ca. Brocadia, Ca. Jettenia and Ca. Kuenenia were the dominant anammox bacteria at all salinities. Ca. Brocadia and Ca. Jettenia were quite sensitive to salinity, and 5 g NaCl/L dosing could cause a sharp decline in their abundance. Nevertheless, these three anammox genus finally survived in the system with a steady specific anammox activity of 0.13 g N g VSS-1d-1. Specially, a novel cluster, Brocadiaceae_unclassified, which possibly belongs to anammox bacteria, became the dominant genus at the salinity over 20 g NaCl/L and likely contributed partially to the nitrogen removals. Our findings elucidated the inherent link between community dynamics and anammox system performance and stability under salty environment, and proved that anammox technologies can be an effective technology for treatment of saline ammonia-rich wastewater.

The objective of this study is to summarize studies and investigations about advanced oxidation processes (AOPs) used for the treatment of petroleum wastewater, which mainly contained oil, organic matter and other compounds. The big difference was shown in the specification of wastewater among the investigated studies and a wide variety of pollutants at varying concentrations. The most compounds in petroleum wastewater were the mixture of hydrocarbons and inorganic compounds. Advanced oxidation processes (AOPs) have a capability of rapid degradation of recalcitrant pollutants in the aquatic environment. However, the literature regarding petroleum wastewater treatment is very little and advanced oxidation processes (AOPs) are still not being used on an industrial scale in oil refineries. Most studies were focused on the degradation of some pollutants found in the petroleum wastewater such as sulphides, ammonia, phenols and organic materials. This review focused on works that investigated advanced oxidation processes (AOPs) by monitoring general petroleum wastewater parameters such as TOC, COD, BOD, oil, and phenols. It presented an overview of photocatalytic degradation of pollutants in petroleum wastewater and highlighted the basics of these processes including the optimum parameters.

In the present study, four beehive matrices (honey, propolis, pollen and bees), sampled from thirteen apiaries from Northern and Western Greece, were analyzed for the presence of Cr, Cu, Mn, Fe, Zn, Mg, and Ca. The proposed method involved microwave digestion with H2O2 and HNO3, dilution with water and direct determination by flame atomic absorption spectrometry. The results showed that the levels of elements in all apicultural products present the following order: Ca > Mg > Zn ≈ Fe > Mn > Cu. Cr was detected at LOD level (0.3 μg g-1) only in some pollen samples from industrial areas. The most abundant elements determined were Ca (3.42 mg g-1) and Mg (1.5
mg g-1) in pollen and propolis. It was also demonstrated that all detected elements are accumulated at higher concentrations in pollen, propolis and bees and to a much lesser extent in honey. Dependence of the content of Mg in honey and of the content of Zn and Cu in pollen, on the geographical origin of samples was identified.

The objective of this study is to summarize studies and investigations and show a brief details of different technologies used for the treatment of petroleum wastewater. The wastewater from Petroleum industries and refineries mainly contains oil, organic matter and other compounds. The treatment of this wastewater can be carried out by physical, chemical and biological treatment processes. Treatment of petroleum wastewater has two stages, firstly, pre-treatment stage to reduce grease, oil and suspended materials. Secondly, an advanced treatment stage to degrade and decrease the pollutants to acceptable discharge values. Most studies are focused on degradation of some pollutants found in the petroleum wastewater such as organic materials, phenols, sulphides and ammonia.