Bioaerosolization behavior along sewage sludge biostabilization

• Aerosolization behavior during a lab-scale sludge biostabilization was determined. • Many pathogenic species were identified to be preferentially aerosolized. • Bioaerosol concentration along the biostabilization ranged from 160 to 1440 cell/m³. • Sludge aerosolization behavior was different with that of other biowaste. Biostabilization is a cost-effective method for the beneficial utilization of sewage sludge. However, during the operation of sludge biostabilization, some microbial species could be released into the atmospheric environment from the solid-phase of sludge easily and present a high risk to human health. This study aimed to evaluate the risk of bioaerosol during sludge biostabilization. We found a total of nine bacterial phyla, one archaeal phylum, and two fungal phyla in the bioaerosol samples. Among them, Proteobacteria, Actinobacteria, Bacteroidetes, and Ascomycota were the dominant phyla. In addition, the bioaerosolization indexes (BI) of prokaryotic phyla and fungal phyla ranged 0–45 and 0–487, respectively. Massilia, Pseudarthrobacter, Pseudomonas, Tremellales spp., and Fusarium were the preferentially aerosolized microbial genera with maximum bioaerosolization indexes of 19962, 10360, 1802, 3055, and 7398. The bioaerosol concentration during the biostabilization ranged from 160 to 1440 cell/m³, and we identified species such as Stenotrophomonas rhizophila and Fusarium graminerum with high bioaerosolization indexes that could be threats to human health. Euryachaeota, which belongs to archaeal phyla, had the highest biostabilization index in our study. We also found that Pseudarthrobacter was the easiest to aerosolize during the sludge biostabilization process.     

New insights into the evaluation of anaerobic properties of sludge: Biodegradability and stabilization

Evaluating anaerobic biodegradability of sludge and then identifying the stabilization of digestate is necessary in sludge treatment and disposal. 48 sludge samples from 24 typical waste water treatment plants (WWTPs) in 11 provinces in China were selected to investigate the relationship between Biochemical Acidogenic Potential (BAP) test and Biochemical Methane Potential (BMP) test. The volatile fatty acid (VFA) production obtained from BAP tests was found linearly related to the ultimate methane production from corresponding BMP tests. Satisfying results were obtained with Pearson correlation coefficient as 0.929 and R² value as 0.76. Furthermore, the physio-chemical characteristics (FCI, SUVA₂₅₄, E₄/E₆) of supernatant, which were associated with humic-like substances (HS), were investigated before and after BMP tests. Through which a new criterion (FCI>1.50, SUVA₂₅₄>1.10, E₄/E₆<4.0) was proposed to evaluate the stabilization level of anaerobic digested sludge.     

壳聚糖改性阳离子絮凝剂的制备及其应用研究

丙烯酰胺与二甲基二烯丙基氯化铵质量比为2∶1时,与壳聚糖发生接枝共聚反应,合成了壳聚糖阳离子型改性高分子絮凝剂PCAD。以高岭土模拟水样为处理体系,探讨了PCAD的絮凝性能,结果表明PCAD是典型的阳离子型高分子絮凝剂。污泥处理试验表明PCAD处理效果优于PAM-C,能显著改善污泥的沉降和脱水性能。     

环境因子对水蚯蚓污泥减量效果的影响

以霍夫水丝蚓（L.hoffmeisteri）为研究对象,考察了生长方式、溶解氧（DO）、酸碱度（pH）和温度（T）对其污泥减量效果的影响.结果表明,附着生长时污泥减量效果优于悬浮生长,附着生长时的TSS、VSS降解率分别为22.34%、29.79%,而游离生长时的TSS、VSS降解率分别仅为15.51%、18.12%;...     

污泥资源化处置与综合利用

介绍了污泥处理的目的、方法,提出污泥应作为一种资源进行综合利用。并结合实例阐述了我国污泥农用资源化处置现状及未来发展趋势。     

城市污水厂污泥中重金属去除及其土地利用的研究现状

污泥中富含磷、氮和钾等农作物需要的营养物质,但碍于污泥中残留的重金属离子而难以使用.文章介绍了污泥中重金属的存在形式及作用机理,综述了几种能有效去除重金属的方法(吸附法、淋滤法和化学法),分析了各种方法的优缺点、影响因素、处理效果、适用范围及处理后土地利用的现状,以期处理后的污泥能够作为农用土地,减轻剩余污泥二次污染危...     

太湖底泥蓄积量估算及分布特征探讨

根据１９９７－１９９９年现场调查资料，分析了太湖污泥淤泥平面和垂直分布特征，估算了太湖各湖区及不同泥厚的底泥淤积面积和蓄积量。结果表明：全湖有６９．８３％面积为污染淤泥所覆盖，厚度最大达５ｍ以上，底泥总蓄积量为１２９．１５亿ｍ＾３，全湖平均底泥厚底为０．８２ｍ。     

蚯蚓生物反应器污泥减量与稳定效果试验研究

蚯蚓生物反应器以蚯矧等微型动物和各种微生物为主形成生物降解系统.城镇污水经生物预处理后,经该反应器过滤,水质得到澄清和进一步改善,而水中含有的生物膜污泥则被滤床截留.通过蚯蚓的吸收、消化和分解转化为蚯蚓排泄物(蚓粪).中试运行结果表明,当蚯蚓生物反应器水力负荷为5.3～6.6 m3/(m2·d)时,在满足污水处理效果条件下,蚯蚓生物反应器对生物膜污泥挥发性悬浮固体(VSS)降解率为86.67%～96.20%.所产生的蚓粪VSS:SS为29.97%～31.20%,有机物降解率超过了厌氧消化与好氧消化处理污泥的效果.减量化和稳定化效果十分明显.该系统排出的蚓粪含有丰富的肥分,可用作农肥与土壤改良剂.     

我国城市污水厂污泥处置途径的选择

分析了我国城市污水厂的污泥特性，结合当前的污染处置技术及其发展趋势，根据国情，提出了近期以及农用为主，填埋，焚烧为补以，面向未来的污泥处置的技术。     

Profiles and removal efficiency of polycyclic aromatic hydrocarbons by two different types of sewage treatment plants in Hong Kong

Sewage discharge could be a major source of polycyclic aromatic hydrocarbons(PAHs) in the coastal waters. Stonecutters Island and Shatin Sewage Treatment Works(SCISTW and STSTW)in Hong Kong, adopted chemically enhanced primary treatment and biological treatment,respectively. This study aimed at(1) determining the removal efficiencies of PAHs,(2) comparing the capabilities in removing PAHs, and(3) characterizing the profile of each individual PAHs, in the two sewage treatment plants(STPs). Quantification of 16 PAHs was conducted by a Gas Chromatography. The concentrations of total PAHs decreased gradually along the treatment processes(from 301 ± 255 and 307 ± 217 ng/L to 14.9 ± 12.1 and 63.3 ± 54.1 ng/L in STSTW and SCISTW, respectively). It was noted that STSTW was more capable in removing total PAHs than SCISTW with average total removal efficiency 94.4% ± 4.12% vs. 79.2% ± 7.48%(p 0.05). The removal of PAHs was probably due to sorption in particular matter, confirmed by the higher distribution coefficient of individual and total PAHs in solid samples(dewatered sludge contained92.5% and 74.7% of total PAHs in SCISTW and STSTW, respectively) than liquid samples(final effluent-total contained 7.53% and 25.3% of total PAHs in STSTW and SCISTW, respectively).Despite the impressive capability of STSTW and SCISTW in removing PAHs, there was still a considerable amount of total PAHs(1.85 and 39.3 kg/year, respectively for the two STPs) being discharged into Hong Kong coastal waters, which would be an environmental concern.