The Auxiliary Effect of Different Bacterial Groups on the Degradation of Organic Matter in Refinery Wastewater by Bacillus Licheniformis

In this paper, the biodegradation of organic compounds in refinery wastewater was studied. Different microbial communities suitable for the treatment of refinery wastewater were selected to degrade the pretreated wastewater. The results showed that the degradation efficiency of COD and ammonia nitrogen was 59.4% and 56.7% respectively; the degradation efficiency of COD and ammonia nitrogen was 50.2% and 60.6% respectively. It can be used as the dominant bacteria for further domestication and cultivation of petrochemical wastewater biological treatment.

Реконструкция воздуходувной станции городских очистных канализационных сооружений г. Читы

Приводятся результаты реконструкции канализационных очистных сооружений г. Читы в части системы снабжения воздухом действующих секций аэротенков без замены воздуходувных агрегатов. Основная цель реконструкции экономия электроэнергии и автоматизация подачи воздуха в аэротенки при обеспечении достаточных концентраций кислорода в сооружениях биологической очистки сточных вод. Для изменения производительности нагнетателей в состав системы автоматики включены два высоковольтных преобразователя частоты по числу нагнетателей, находящихся в работе. Для регулирования подачи воздуха в секции аэротенков установлены восемь регулируемых затворов и восемь датчиков растворенного кислорода (по числу действующих секций). Экономия электроэнергии за четыре месяца эксплуатации составила порядка 16,4 от аналогичного периода прошлых лет.The results of the reconstruction of the wastewater treatment facilities in the city of Chita are presented with regard to the system of supplying air to the operating sections of the aeration tanks without replacing the air blower units. The main goal of the reconstruction was energy saving and automation of air supply to the aeration tanks while ensuring sufficient oxygen concentrations in the wastewater biological treatment facilities. To change the capacity of the air blowers the automation system includes two highvoltage frequency converters for the number of blowers in operation. To regulate the air supply eight regulated valves and eight dissolved oxygen sensors (for the number of operating sections) are installed in the sections of the aeration tanks. Energy savings over four months of operation amounted to about 16.4 compared to the same period of previous years.

Cost Effective Method for Toxicity Screening of Pharmaceutical Wastewater Containing Inorganic Salts and Harmful Organic Compounds

Pharmaceutical wastewater biological treatment plants are stressed with multi-component wastewater and unexpected variations in wastewater flow, composition and toxicity. To avoid operational problems and reduced wastewater treatment efficiency, accurate monitoring of influent toxicity on activated sludge microorganisms is essential. This paper outlines how to predict highly toxic streams, which should be avoided, using measurements of biochemical oxygen demand (BOD), if they are made in a wide range of initial concentration. The results indicated that wastewater containing multivalent Al3+ cations showed a strong toxic effect on activated sludge biocenosis irrespectively of dilutions, while toxicity of phenol and formaldehyde containing wastewater decreased considerably with increasing dilution. Activated sludge microorganisms were not sensitive to wastewater containing halogenated sodium salts (NaCl, NaF) and showed high treatment capacity of saline wastewater. Our findings confirm that combined indicators of contamination, such as chemical oxygen demand (COD), alone do not allow evaluating potential toxic influence of wastewater. Obtained results allow identifying key inhibitory substances in pharmaceutical wastewater and evaluating potential impact of new wastewater streams or increased loading on biological treatment system. Proposed method is sensitive and cost effective and has potential for practical implementation in multiproduct pharmaceutical wastewater biological treatment plants.