Pilot study on the upgrading configuration of UASB-MBBR with two carriers: Treatment effect,sludge reduction and functional microbial identification

Two kinds of biocarriers were adopted and a combined process of “AMC (Anaerobic microorganism carrier)-UASB and PBG (Porous bio-gel)-MBBR” was operated at the pilot scale for the treatment of real textile wastewater. The influence mechanism of the two carriers on the start-up, pollutant removal and sludge reduction were investigated within 118 days of operation. The dominant functional bacteria in anaerobic and aerobic systems were identified by high-throughput sequencing, and the possible ways and related mechanisms of nutrient removal and sludge reduction were analyzed based on the data. 37.0 ± 7.5 % and 53 ± 12.7 % of COD removal efficiencies were achieved in anaerobic system and aerobic system, respectively. Ammonia nitrogen concentration decreased from 20 to 45 to 3.49 ± 0.54 mg/L after treatment. An anaerobe was found to be closely related to color removal, which existed in both anaerobic and aerobic systems, achieving 84.0 % of color removal. With the operation of the system, the sludge yield decreased gradually. The sludge yields of anaerobic and aerobic systems were calculated individually and compared with similar studies. Aging biofilms were characterized to explore the factors associated with biofilm renewal.     

Nitrate-Removal Activity of a Biofilm Attached to a Perlite Carrier under Continuous Aeration Conditions

The nitrate-removal activity of a biofilm attached to a perlite carrier from an aerobic bioreactor used for treating dairy farm wastewater was examined by batch experiments under continuous aeration conditions. Despite aeration, the biofilm removed nitrate at a rate of 114.4 mg-N/kg-perlite/h from wastewater containing cow milk and manure. In a clone library analysis of the biofilm, bacteria showing high similarity to the denitrifying bacteria Thauera spp. were detected.     

Rendiconti Delle Sedute E Brevi Comunicazioni

Abstract

The development of effective strategies to rehabilitate compromised environments is one of the major challenges facing the postindustrial society, since most of the habitats are becoming progressively polluted due to indiscriminate discharge of contaminants generated by anthropogenic activities. Several aquatic photosynthetic organisms can be used to treat wastewaters in primary and tertiary treatments, including cyanobacteria, algae and higher plants. In this review, we summarize the results obtained in the remediation of polluted waters by photosynthetic organisms and discuss the future perspective of phytoremediation.     

Pleurotus ostreatus biofilm‐forming ability and ultrastructure are significantly influenced by growth medium and support type

Aims

To investigate the effect of support and growth medium (GM) on Pleurotus ostreatus biofilm production, specific metabolic activity (SMA) and ultrastructure.

Methods and Results

Biofilms were developed on membranes covering a broad range of surface properties and, due to the applicative implications of mixed biofilms, on standard bacterial GM in stationary and shaken culture. Hydrophilic (glass fibre, Duran glass and hydroxyapatite) and mild hydrophobic (polyurethane, stainless steel, polycarbonate, nylon) supports were more adequate for biofilm attachment than the hydrophobic Teflon. Among the GM, sucrose–asparagine (SA) was more conducive to biofilm production than Luria–Bertani and M9. GM was more influential than support type on biofilm ultrastructure, and a high compactness was evident in biofilms developed on SA. Biofilms on Duran glass were more efficient than planktonic cultures in olive‐mill wastewater treatment.

Conclusions

The main effects of support and GM variables and their binary interactions on both biofilm production and SMA were all highly significant (P < 0·001): thus, the magnitude of the effect of each variable strongly depended on the level of the other one.

Significance and Impact of the Study

There is a lack of basic information regarding physiology and ultrastructure of P. ostreatus biofilms. To our knowledge, this is the first attempt to fill this gap, thus representing a basis for future studies.     

Biological detoxification of precious metal processing wastewaters

A biological treatment plant is utilized at the Homestake Mine in Lead, SD, to effect detoxification of a daily discharge of 4 million gallons of wastewater. The wastewater matrix requiring treatment contains cyanide, ammonia, toxic heavy metals, and a variable component of toxic chemicals associated with extractive metallurgy and mining operations. Rotating biological contactors (RBCs) are used to attach the biofilm. Cyanides and heavy metals concentrations are reduced by 95–98%. The treated discharge makes up as much as 60% of the total flow in a cold‐water trout fishery. This receiving stream, which remained lifeless for over 100 years as a mine drainage, has now become an established trout fishery and recently yielded a state record trout.     

污水处理厂生物气溶胶抗生素抗性污染特征、来源及潜在风险

污水处理厂是抗生素抗性基因（antibiotic resistance genes,ARGs）和抗生素抗性细菌（antibiotic resistant bacteria,ARB）重要的源和汇,生物气溶胶是ARGs和ARB自污水处理厂向周边环境释放的关键载体。目前缺乏对污水处理厂生物气溶胶抗生素抗性污染特征、来源及潜在风险的系统性总结。本文从采样方法、检测方法、逸散特征、来源、潜在危害和风险评估等方面对污水处理厂抗生素抗性污染研究现状进行综述。惯性采样法和过滤法是常用的污水处理厂抗生素抗性生物气溶胶主要采集方法,而宏基因组测序、组装和分箱为其ARGs组成、可移动性和宿主提供了有效的检测方法,抗多药类、抗杆菌肽类、抗氨基糖苷类、抗四环素类、抗β-内酰胺类、抗磺胺类、抗大环内酯类和抗糖肽类等抗性基因在污水处理厂PM₁₀、PM_2.5和PM_1.0颗粒物中广泛检出。格栅间、生化反应池和污泥处理单元是污水处理厂PM₁₀、PM_2.5和PM_1.0负载ARGs和ARB的主要释放单元。污水处理厂不同粒径生物气溶胶中致病性ARB的存在增加了抗生素治疗的难度,而污水和污泥对ARGs和ARB的释放起到了重要的源的贡献。本文在研究内容、研究技术和控制策略等方面也提出了相关展望,以期为污水厂生物气溶胶抗生素抗性污染的监测和防护提供参考和借鉴。     

Proteogenomic Refinement of the Neomegalonema perideroedesT Genome Annotation

Neomegalonema perideroedes (formerly Meganema perideroedes) str. G1 is the type strain and only described isolate of the genus Neomegalonema (formerly Meganema) which belongs to the Alphaproteobacteria. N. perideroedes is distinguished by the ability to accumulate high amounts of polyhydroxyalkanoates and has been associated with bulking problems in wastewater treatment plants due to its filamentous morphology. In 2013, its genome was sequenced as part of the Genomic Encyclopedia of Bacteria and Archaea (GEBA), which aims to improve the sequencing coverage of the poorly represented regions of the bacterial and archaeal branches of the tree of life. As N. perideroedes str. G1 is relatively distantly related to well described species—being the only sequenced member of its proposed family—the in silico prediction of genes by nucleotide homology to reference genes might be less reliable. Here, a proteomic dataset for the refinement of the N. perideroedes genome annotations is generated which clearly indicates the shortcomings of high‐throughput in silico genome annotation.     

The enhanced effect of supplemented lighting on nutrient removal by an aquatic vegetables (lettuce) purification system from rural domestic sewage

Abstract

Aquatic plant treatment system (APTS) is a widely used sewage purification technique; however, it requires a large area of land due to its long hydraulic retention time. In order to improve the economic value of APTS in the treatment of rural sewage, an aquatic vegetables (lettuce) purification system strengthened with a set of supplemented lighting was evaluated. The effect of supplemented lighting of blue and red light on lettuce growth and sewage purification was studied by batch experiments. The results showed that the lettuce growth and the removal rates of pollutants were enhanced by supplemented lighting, of which red light is superior to blue light, and the increase of red light intensity further promoted the growth of lettuce and the removal rate of pollutants. Supplementary light is a suitable method which could improve the purification effect of APTS in most weather conditions especially in countries where day-night light patterns change substantially between winter and summer. The results would be useful for the APTS design for treating rural domestic sewage.