Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
Sci Total Environ. 2019 Aug 10;677:120-130. doi: 10.1016/j.scitotenv.2019.04.304. Epub 2019 Apr 24.
Nowadays, due to worldwide water shortage, water utilities are forced to re-evaluate treated wastewater. Consequently, wastewater treatment plants need to conduct biomonitoring. Coking wastewater (CWW) has toxic, mutative and carcinogenic components with threatening effect on the environment. CWW was selected as a model for complex highly toxic industrial wastewater that should be treated. CWW from Egypt was treated in a nine-liter photobioreactor using an algal-bacterial system. The photobioreactor was operated for 154 days changing different parameters (toxic load and light duration) for optimization. Optimized conditions achieved significant reduction (45%) in the operation cost. The algal-bacterial system was monitored using chemical assays (chemical oxygen demand and phenol analysis), bioassays (phytotoxicity, Artemia-toxicity, cytotoxicity, algal-bacterial ratio and settleability) and Illumina-MiSeq sequencing of 16S rRNA gene. The algal-bacterial system detoxified (in terms of phytotoxicity, cytotoxicity and Artemia-toxicity) CWW introduced as influent through all phases. A significant difference was recorded in the microbial diversity between influent and effluent samples. Four phyla dominated influent samples; Proteobacteria (77%), Firmicutes (11%), Bacteroidetes (5%) and Deferribacteres (3%) compared to only two in effluent samples; Proteobacteria (66%) and Bacteroidetes (26%). The significant relative-abundance of versatile aromatic degraders (Comamonadaceae and Pseudomonadaceae families) in influent samples conformed to the nature of CWW. Microbial community shifted and promoted the activity of catabolically versatile and xenobiotics degrading families (Chitinophagaceae and Xanthomonadaceae). Co-culture of microalgae had a positive effect on the biodegrading bacteria that was reflected by enhanced treatment efficiency, significant increase in relative abundance of bacterial genera with cyanide-decomposing potential and negative effect on waterborne pathogens.
如今，由于全球水资源短缺，供水公司被迫重新评估处理后的废水。因此，污水处理厂需要进行生物监测。焦化废水（CWW）含有有毒、突变和致癌成分，对环境具有威胁作用。CWW 被选为需要处理的复杂、高毒性工业废水的模型。埃及的 CWW 在一个 9 升的光生物反应器中使用藻类-细菌系统进行处理。光生物反应器运行了 154 天，改变了不同的参数（毒性负荷和光照时间）以进行优化。优化条件使运行成本显著降低（45%）。使用化学分析（化学需氧量和苯酚分析）、生物测定（植物毒性、卤虫毒性、细胞毒性、藻类-细菌比例和沉降性）和 Illumina-MiSeq 测序 16S rRNA 基因监测藻类-细菌系统。藻类-细菌系统通过所有阶段对进水（以植物毒性、细胞毒性和卤虫毒性为指标）中的 CWW 进行解毒。在进水和出水样品之间记录到微生物多样性有显著差异。进水样品中优势的四个门为变形菌门（77%）、厚壁菌门（11%）、拟杆菌门（5%）和脱硫杆菌门（3%），而在出水样品中仅为两个门；变形菌门（66%）和拟杆菌门（26%）。进水样品中多功能芳香化合物降解菌（Comamonadaceae 和 Pseudomonadaceae 科）的相对丰度显著，符合 CWW 的性质。微生物群落发生了变化，并促进了具有代谢多功能性和异生物质降解能力的家族（噬几丁质菌科和黄单胞菌科）的活性。微藻共培养对具有生物降解能力的细菌有积极影响，这反映在处理效率的提高、具有氰化物分解潜力的细菌属的相对丰度显著增加以及对水传播病原体的负面影响上。
