Steel production processes generate the coke wastewaters contaminated predominantly by highly toxic phenol. Numbers of physical, chemical and physicochemical methods have been developed for the removal of phenol from coke wastewaters. Biological methods are eco-friendly and present appropriate alternative of conventional processes. Various microorganisms are able to degrade phenolic compounds including sulphate-reducing bacteria (SRB). In this work, we study the adaptation of SRB isolated from natural source to phenol and consequently the application of the adapted bacterial cultures for the biodegradation of phenol from model solutions. Two types of bacterial culture were used (monoculture containing SRB genera Desulfovibrio and mixed bacterial consortium containing SRB genera Desulfovibrio). In experiments the modified Postgate’s medium C was used - sodium lactate as the original energy and carbon source was replaced by phenol with concentration 10 mg/dm3 for adaptation and 50 mg/dm3 for biodegradation. The mixed bacterial consortium has been shown as more capable to be adapted and grow on phenol and it has the better potential for phenol biodegradation as the bacterial monoculture of SRB genera Desulfovibrio.
The objective of this work was the application of innovative method for metals recovery from metalliferous mine water released from the flooded siderite ore deposit Nižná Slaná. Although the metals contained in mine drainage are considered environmental pollutants, they may also be recognised as valuable resources. Several techniques can be used to obtain them by precipitation. Conventional processes using alkaline reagents produce huge amounts of mixed sludge with appropriate storage and management requirement, void of possibility of individual metals subsequent processing. This study examined the feasibility of Fe and Mn selective retrieval from real mine water. After oxidation and partial precipitation of iron using hydrogen peroxide, precipitation by sodium hydroxide was applied to the residue iron removal from mine water. In the next step potassium permanganate was used to eliminate manganese by oxidative precipitation. ORP and pH values of processed mine water was recorded in the course of oxidation/precipitation processes. The morphology and elemental composition of obtained products were studied by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The recovery efficiencies of Fe and Mn from mine water reached 99.87 % and 99.25%, respectively. Target metals were removed with high selectivity to levels that comply with environmental requirements.
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