Biodegradation by bioaugmentation of dairy wastewater by fungal consortium on a bioreactor lab-scale and on a pilot-scale

A fungal consortium including Aspergillus niger, Mucor hiemalis and Galactomyces geotrichum was tested for the treatment of dairy wastewater. The bio-augmentation method was tested at lab-scale (4 L), at pilot scale (110 L) and at an industrial scale in Wastewater Treatment Plants (WWTP). The positive impact of fungal addition was confirmed when fungi was beforehand accelerated by pre-culture on whey (5 g/L lactose) or on the dairy effluent. Indeed, chemical oxygen demand (COD) removal yields increased from 55% to 75% for model medium, diluted milk. While after inoculation of an industrial biological tank from a dairy factory with the fungal consortium accelerated by pre-cultivation in a 1000 L pilot plant, the outlet COD values decreased from values above the standard one (100 mg/L) to values in the range of 50-70 mg/L. In addition, there was a clear impact of fungal addition on the ’hard’ or non-biodegradable COD owing to the significant reduction of the increase of the COD on BOD 5 ratio between the inlet and the outlet of the biological tank of WWTP. It was in the range of 451%-1111% before adding fungal consortium, and in the range of 257%-153% after bio-augmentation with fungi. An inoculated bioreactor with fungal consortium was developed at lab-scale and demonstrated successfully at pilot scale in WWTP.     

Iron and lead ion adsorption by microbial flocculants in synthetic wastewater and their related carbonate formation

Although microbial treatments of heavy metal ions in wastewater have been studied, the removal of these metals through incorporation into carbonate minerals has rarely been reported. To investigate the removal of Fe^3＋ and Pb^2＋, two representative metals in wastewater, through the precipitation of carbonate minerals by a microbial flocculant （MBF） produced by Bacillus mucilaginosus. MBF was added to synthetic wastewater containing different Fe^3＋ and Pb^2＋ concentrations, and the extent of flocculation was analyzed. CO2 was bubbled into the mixture of MBF and Fe^3＋/Pb^2＋ to initiate the reaction. The solid substrates were analyzed via X-ray diffraction, transmission electron microscopy and energy dispersive spectroscopy. The results showed that the removal efficiency decreased and the MBF adsorption capacity for metals increased with increasing heavy metal concentration. In the system containing MBF, metals （Fe^3＋ and Pb^2＋）, and CO2, the concentrated metals adsorbed onto the MBF combined with the dissolved CO2, resulting in oversaturation of metal carbonate minerals to form iron carbonate and lead carbonates. These results may be used in designing a method in which microbes can be utilized to combine CO2 with wastewater heavy metals to form carbonates, with the aim of mitigating environmental problems.     

Numerical simulation of alga growth and control in Dalian Bay

WAHMO model was used to simulate the distribution of pollutants in Dalian Bay, China as to predict well as the growth and control of alga. The observed and predicted values of main pollutants showed a good trend at all study locations and the different between them can be ignored. Simulation results illustrated that phosphate was one of limited factors to control algal growth at the location near the sewage outfall, meanwhile, away from the sewage outfall, the synergy of ammonium nitrogen and phosphate was the limited factor.     

Waste oyster shell as a kind of active filler to treat the combined wastewater at an estuary

Estuaries have been described as one of the most difficult environments on Earth. It is difficult to know how to treat the combined wastewater in tidal rivers at the estuary, where the situation is very different from ordinary fresh water rivers. Waste oyster shell was used as the active filler in this study in a bio-contact oxidation tank to treat the combined wastewater at the Fengtang Tidal River. With a middle-experimental scale of 360 ma/day, the average removal efficiency of COD, BOD, NH3-N, TP and TSS was 80.05%, 85.02%, 86.59%, 50.58% and 85.32%, respectively, in this bio-contact oxidation process. The living microbes in the biofilms on the waste oyster shell in this bio-contact oxidation tank, which were mainly composed of zoogloea, protozoa and micro-metazoa species, revealed that waste oyster shell as the filler was suitable material for combined wastewater degradation. This treatment method using waste oyster shell as active filler was then applied in a mangrove demonstration area for water quality improvement near the experiment area, with a treatment volume of 5 × 10^3 m^3/day. Another project was also successfully applied in a constructed wetland, with a wastewater treatment volume of 1 ×10^3 m^3/day. This technology is therefore feasible and can easily be applied on a larger scale,     

呼和浩特地区污水厂能耗评价与碳排放分析

污水处理过程的能耗和温室气体排放方面的研究对于应对能源危机和气候危机具有重要作用。文章利用层次分析法,建立了具有4层15项指标的能耗评价体系。结合城镇污水处理系统的绿色指标体系,选取呼和浩特地区具有代表性、处理规模相近的2座中小型污水厂进行能耗评价。结果表明:处理能力利用率、处理工艺系统稳定性和污水厂高程布置所对应的3项评价指标在所选择的能耗影响因素中所占权重较大,分别为:0.143 0,0.302 4和0.145 6。进一步运用IPCC计算方法对污水处理厂进行碳排放概算,得出A、B污水处理厂的碳排放量分别为:19.401 t CO2/104t、18.378 t CO2/104t。A、B污水处理厂的实际比能耗分别为0.293 kW.h/m3、0.195 kW.h/m3。将碳排放数据与实际能耗情况对比得出:污水处理厂的能耗水平越高,单位碳排放量也越大。     

基于生命周期评价的城市固体废弃物处理模式研究进展

通过回顾2003-2010年国内外不同城市固体废弃物管理体系生命周期评价结果,列举比较了不同固体废弃物处理模式下的全球变暖潜力、酸化潜力和净能源效用等影响评价因子的大小,得出城市固体废弃物处理模式环境影响等级:填埋的环境影响潜值最大,焚烧的环境影响潜值小于填埋,而结合堆肥后环境影响潜值降低;此外,将固体废弃物资源化引入到处理模式后,特别是垃圾源头分类回收后,环境影响潜值大大降低。结合我国城市固体废弃物处理现状,提出单一的处理模式应转变为综合处理模式,多种生活垃圾处理方式适当的有机结合,因地制宜地开展固体废弃物资源化管理,以及餐厨垃圾源头分类收集处理等建议,为政府能有效利用城市固体废弃物处理设施的能力提供参考。     

植穴控制体对盐渍土生态重建的可持续性评价

基于盐渍土生态重建过程影响因子的复杂性,采用综合指标评价方法,选取4类母指标和相应的13项子指标对植穴控制体生态重建技术进行可持续评价。4类母指标分别为土壤养分与结构改良程度、生产力持续水平、组分间关系协调性和生态、社会效益,对应的13项子指标分别为:土壤水分、土壤含盐量、土壤养分含量、土壤容重和水质;土地利用效果、土地生产力水平与稳定度、绿地结构与环境功能;生态重建年限、生物群落变化和生态景观效果;小气候效益和游憩的功能效益。经权重分析认为,植穴控制体生态重建技术评价分值为0.772,评价等级为Ⅳ级,表明植穴控制体模式的盐渍土生态重建技术具有较好的稳定性和可持续的功能效应。     

滇池沿湖地区农田污染生态控制关键技术研究

针对滇池沿湖地区农田面源污染的特点,结合种植生产实际情况,在分析已有研究成果的基础上,按照源-流-汇系统控制的思路,在滇池沿湖地区开展了大颗粒肥料加工施用技术;生物覆盖保护性栽培技术;沟-基-塘系统三项试验研究。实验表明生态控制技术对农田地表径流污染综合负荷TN、TN、CODCr和SS的平均去除率分别达到54.14%～59.78%、66.86%～69.45%、42.20%～62.74%和48.83%～76.41%。生态控制技术的集成研究应用对于滇池沿湖地区生态农业发展和农田面源污染防控具有良好的作用。     

浅谈环境空气自动监测站质控方式

采用标准样品检查、PM10采样流量检查和运行管理检查等方式,加强对云南省环境空气自动监测站的质量管理和质量控制,保证了仪器设备的可靠运行和监测数据准确有效。实践证明,这套检查方式操作简单、易于实施、效果较好。     

富营养化湖泊中微囊藻毒素及其控制去除技术

微囊藻水华是湖泊水体中产生最频繁、危害最严重的一类。微囊藻毒素作为富营养化水体中最常见的藻类毒素,获得了国内外的广泛关注与研究报道。我国淡水水体受微囊藻毒素污染的程度已经相当严重,尤其是饮用水水源的污染,对人们的健康构成了极大的危害。因此当前急需确认藻类毒素对我国水环境影响的程度,研究蓝藻水华产毒的生态条件及控制去除途径,探索毒素对人体健康的影响和防治对策,目前关于微囊藻毒素的健康效应的研究多是从饮用水角度出发,今后的研究可收集详细的数据以建立危险性评估模型,并评价各种降低微囊藻毒素危险性措施的效果。文章就微囊藻毒素的产生、性质与结构、对环境与人类健康的危害、以及微囊藻毒素在水处理过程中的控制方法等方面的研究进展进行了综述,并提出了研究展望。