人工湿地废水处理系统的生物学基础研究进展

主要阐述了人工湿地废水处理系统中生物学基础的研究进展,至今,对作为湿地生产者的水生植物研究较多,水生植物除直接吸收利用废水中的营养物质,吸附和富集重金属外,还起输送氧气至根区,形成根区多种微环境和维护湿地水力传输的作用;而对作为湿地分解者的微生物的研究较少,湿地微生物的代谢活动是废水中有机物质降解的基础机制。     

Impurity effect on clear water evaporation: toward modelling wastewater evaporation using ANN,ANFIS-SC and GEP techniques

The growing shortage of freshwater resources and increasing environmental awareness give rise to the use of treated wastewater as an alternative resource for water supply. Accurate estimation of wastewater evaporation (WWE), as the main cause of water losses, is necessary for proper water resources management. Unfortunately, few studies have focused on modelling WWE despite its vital importance. This study investigates the ability of gene expression programming (GEP), adaptive neuro-fuzzy inference system (ANFIS) and artificial neural networks (ANN) techniques to estimate WWE as a function of variables including wastewater properties, clear water evaporation and climatic factors. The study uses measured data from an experiment conducted in Neishaboor municipal wastewater treatment plant, Iran. Results indicate that the ANN model is superior among the three methods, and also demonstrates higher accuracy when compared with those of a dimensional analysis model using the F-test statistic.     

Response Surface Modeling and Optimization of Microwave‐Activated Persulfate Oxidation of Olive Oil Mill Wastewater

Olive oil mill wastewater (OMW) is environmentally hazardous not only because it contains high recalcitrant and toxic compounds, but also due to its high organic load and turbidity. In this study, oxidation of OMW by microwave (MW)‐activated persulfate is investigated. Box–Behnken design is applied to investigate the effects of operating conditions on operating cost, organic matter, and color removal. Multi response optimization is performed according to minimum operating cost, maximum organic matter and color removal efficiencies. At optimum conditions (persulfate anion dose of 266 g L^?1, oxidation duration of 23.58 min, MW power of 567 W, and initial pH 2), chemical oxygen demand (COD) removal of 63.38%, color removal of 94.85%, and operating cost of 0.0633 Euro/g total organic carbon (TOC) removal are found. The biochemical oxygen demand (BOD₅)/COD ratio is increased from 0.144 to 0.285. Results of Pareto analysis show individual effect of MW power is 92.81% for TOC removal, 15.52% for color removal, 68.99% for operating cost, respectively. According to the results, it is not recommended to use this process as an ultimate treatment unit due to the high amount of oxidizing agent consumed. Instead, it is recommended to be used as a pre‐ or post‐treatment step.     

Biodegradation by Co‐inoculated Bacteria and Fungi Alleviates Adverse Effects of Red‐S3B on Growth and Nitrogen Uptake of Wheat

Textile wastewater contains huge quantities of nitrogen (N)‐containing azo‐dyes. Irrigation of crops with such wastewater adds toxic dyes into our healthy soils. One of the ways to prevent their entry to soils could be these waters after the dyes' biodegradation. Therefore, the present study was conducted to evaluate the impact of textile dyes on wheat growth, dye degradation efficiency of bacteria‐fungi consortium, and alleviation of dye toxicity in wheat by treatment with microbial consortium. Among dyes, Red‐S3B (3.19% N) was found to be the most toxic to germination and growth of seven‐day‐old wheat seedlings. Shewanella sp. NIAB‐BM15 and Aspergillus terreus NIAB‐FM10 were found to be efficient degraders of Red‐S3B. Their consortium completely decolorized 500 mg L^?1 Red‐S3B within 4 h. Irrigation with Red‐S3B‐contaminated water after treatment with developed consortium increased root length, shoot length, root biomass, and shoot biomass of 30‐day‐old wheat seedlings by 47, 18, 6, and 25%, respectively, than untreated water. Moreover, irrigation after microbial treatment of dye‐contaminated water resulted in 20 and 51% increase in shoot N content and N uptake, respectively, than untreated water. Thus, co‐inoculation of bacteria and fungi could be a useful bioremediation strategy for the treatment of azo‐dye‐polluted water.