加工番茄污水污泥生物好氧发酵对有机污染物的降解及其影响因素

通过研究加工番茄污水污泥的有机污染物降解变化和好氧发酵条件(含水量、p H、C/N、含氧量和CO2)来确定番茄污水中有机污染物降解情况,从而优化加工番茄废水处理。结果表明:最佳生物好氧发酵条件为含水量60%~80%,C/N范围为5~10,氧气浓度10%,p H=6.5,污泥发酵15 h后,有机物降解速率达到平衡。     

中国城市污泥土地利用关注的典型有机污染物

污泥土地利用是国内外城市污泥主要的处置方式之一,而污泥中的有机污染物是污泥土地利用的限制性因素之一.本文分析了国内外城市污泥中有机污染物的浓度和研究现状,针对我国国情,认为多环芳烃(PAHs)是城市污泥中一种常见的有机污染物,总含量一般在1 ～ 10 mg·kg-1,有的因污水来源复杂而超过了100 mg·kg-1;壬基苯酚(NP/NPE)在我国污水处理厂污泥样品中均有检出,浓度在1～128 mg·kg-1.污泥园林绿化、林地利用、土壤改良等将是今后主要的利用方向,要实现污泥安全、环保的土地利用,多环芳烃(PAHs)和壬基苯酚(NP/NPE)将是主要考虑的典型有机污染物.     

降解苯胺和氯苯胺类污染物好氧污泥颗粒化及微生物种群结构分析

以序批式气提生物反应器(SABR)为平台,研究了苯胺和氯苯胺类有毒有机废水处理过程好氧污泥颗粒化。结果表明,通过缩短污泥沉降时间、逐步提升目标污染物进水负荷,反应器连续运行3个月,最终在污泥沉降时间5min、COD负荷1.0~3.6kg/(m3.d)、苯胺和氯苯胺负荷1kg/(m3.d)条件下实现污泥颗粒化,COD、苯胺和氯苯胺去除率分别稳定在90%、99.9%以上;获得的成熟好氧颗粒粒径在0.45~2.5mm,SOUR稳定在150mgDO/(gVSS·h)以上,颗粒污泥EPS中PN含量为28.0±1.9mg/gVSS,PN/PS比值为6.5mg/mg,苯胺类比降解速率达0.18g/(g·d);应用PCR-DGGE分子指纹图谱技术分析了稳定运行的颗粒化反应器内好氧污泥微生物种群结构,结果表明好氧颗粒内主要细菌分属β-Proteobacteria、γ-Proteobacteria及Flavobacteria等类群,优势菌为Pseudomonas sp.、Flavobacterium sp.;与已获得的降解氯苯胺好氧颗粒相比,苯胺存在下培养获得的好氧颗粒污泥微生物菌群结构更为丰富。     

氧对膜生物反应器短程硝化的影响

为了研究膜生物反应器的短程硝化性能以及氧对短程硝化的影响,通过对比耗氧率和供氧率,提出了膜生物反应器短程硝化的控制优化建议。在膜生物反应器硝化过程中,DO小于1 mg/L开始出现亚硝氮积累;DO降到0.5 mg/L,出水氨氮浓度与亚硝氮浓度之比接近1∶1;DO调控在0.5-1 mg/L范围内,有利于前置硝化反应器与后续厌氧氨氧化反应器衔接。膜生物反应器中污泥浓度可达20 g/L,耗氧能力可达19.86 mg O2/(L·s),但最大供氧能力仅为0.369 mg O2/(L·s),供氧成为反应器运行的制约瓶颈,"低DO高流量"曝气是继续提高短程硝化效能的控制策略。     

含油污泥微生物处理技术研究

针对胜利油田现河采油厂和滨南采油厂联合站罐底污泥的含油污泥进行了微生物处理技术研究工作。主要是利用微生物分离含油污泥的油、泥和降解污泥中的污染物的性能,达到油泥分离和污染物降解的目的。经过了微生物的分离、筛选和诱导培养,选育到了合适的菌株,利用该菌株对含油污泥经厌氧处理后再进行好氧脱油实验,对污泥中脱出原油进行回收。结果表明：所选菌株可以使含油23000mg/kg的含油污泥在4h内脱油到。10100mg/kg,脱油率达到53．4％;微生物降解实验中,随着时间的延长,油去除率越高,降解效果越明显,当处理时间为60d处理后的污泥达到排放标准。     

中国城市污泥有机质及养分含量与土地利用

土地利用是城市污泥的重要处理处置方法,其有机质和养分含量是土地利用中很受关注的问题。关于中国的城市污泥虽然已有不少研究报道,但不同研究结果之间结论并不一致,且缺乏系统的总结。通过系统搜集了20世纪80年代以来全国城市污泥相关的文献资料,重点评述中国城市污泥的有机质含量及其土地利用问题。通过29个城市污泥组成的统计分析发现,中国城市污泥(不包括工业污泥)的有机质平均含量达到384g／kg,全氮、全磷和全钾分别为27、14．3和7g／kg;有机质、全氮、全磷比纯猪粪分别高出1／3～2／3,但全钾比纯猪粪低1／3。中国城市污泥的有机质含量呈逐年增加的趋势,但氮、磷含量变化规律不明显。研究证明,城市污泥在粮食作物、蔬菜、经济作物及园林绿地上使用,具有明显的肥效和改良土壤的效果。近年来,城市污泥中重金属含量越来越低,这有利用促进城市污泥的土地利用,但中国在有机污染物和病原体的危害方面研究相对较少,对城市污泥土地利用的潜在风险仍缺乏长期的定位试验研究。     

城市污泥中邻苯二甲酸酯(PAEs)的厌氧微生物降解

邻苯二甲酸酯(PAEs)是城市污泥中普遍存在的一类具有内分泌干扰性作用的有机污染物.研究污泥厌氧生物处理过程中PAEs的微生物降解对保障污泥农用的安全性十分必要.本文以污泥中两种主要的PAEs——邻苯二甲酸二丁酯(DBP)和邻苯二甲酸(2-乙基己)酯(DEHP)为研究对象,通过比较PAEs在污泥厌氧消化系统与发酵产氢系统中降解过程的差异及系统污泥特性的变化,分析不同污泥厌氧生物处理系统中影响PAEs降解的可能因素.结果表明: 在污泥厌氧发酵系统中,DBP在6 d内降解率达99.6%, DEHP在整个14 d的培养期间也降解了46.1%;在发酵产氢系统中,在14 d培养过程DBP的降解率仅为19.5%,DEHP则没有明显的降解.与厌氧消化系统相比,PAEs在发酵产氢系统中的降解受到明显抑制,这与发酵产氢过程中微生物量下降、革兰氏阳性菌/革兰氏阴性菌(G⁺/G^-)和真菌/细菌变小及挥发性脂肪酸(包括乙酸、丙酸及丁酸)浓度升高有关.     

鄂西北丹江口库区大气氮沉降

利用雨量器在鄂西北丹江口库区连续3a采集降雨样品,研究了大气氮沉降的变化动态。结果表明:2009—2011年月均总氮(TN)浓度为3.70—10.36 mg/L,与当月降雨量呈极显著线性负相关(R=-0.592**,n=32),季均TN浓度为冬季(8.21 mg/L)春季(3.94 mg/L)秋季(3.23 mg/L)夏季(2.70 mg/L),年均TN浓度为3.70 mg/L。大气氮素年均干湿总沉降量为26.53 kg/hm2,其中干沉降为7.80 kg/hm2,占总沉降量的29.4%;湿沉降为18.73 kg/hm2,占总沉降量的70.6%。干沉降中铵态氮(NH+4-N)、硝态氮(NO-3-N)、可溶性有机氮(DON)和颗粒态氮(PN)分别占TN的22.1%、16.8%、37.2%和23.9%,湿沉降中它们分别为TN的36.6%、34.4%、12.9%和16.1%。     

互花米草盐沼土壤有机碳库组分及结构特征

在江苏盐城互花米草(Spartina alterniflora)盐沼建立以下样地:光滩(Mudflat)、互花米草建群1a(S.alterniflora flat 2011)、5a(S.alterniflora flat 2007)、12a(S.alterniflora flat 2000)、23a(S.alterniflora flat 1989)以及碱蓬(Suaeda salsa flat 1989),采集表层土壤样品,分析土壤中的活性有机碳(可溶性有机碳、微生物量碳)特征,并利用核磁共振波谱法测定土壤总有机碳的结构图谱,研究互花米草盐沼土壤有机碳库组分及结构特征。结果表明:(1)互花米草建群后,盐沼表层土壤有机碳含量显著增加(P0.05),在0.82—7.6 g/kg之间,各样地表层土壤有机碳含量为:互花米草滩(5.57 g/kg)碱蓬滩(2.4 g/kg)光滩(1.05 g/kg);可溶性有机碳含量为:互花米草滩(36.08 mg/kg)碱蓬滩(17.43 mg/kg)光滩(6.92 mg/kg);微生物量碳含量为:互花米草滩(52.51 mg/kg)碱蓬滩(18.27 mg/kg)光滩(13.56 mg/kg)。互花米草建群后,土壤中活性碳库含量显著增加(P0.05)。(2)土壤有机碳结构以烷氧碳和芳香碳为主,其中芳香碳的平均比例(35.85%)最高,其次为烷氧碳(32.83%)和羧基碳(20.62%),烷基碳的平均比例(10.36%)最低,其中建群5a的互花米草样地(SAF2007)土壤芳香碳、烷氧碳、烷基碳含量最高,建群23a的互花米草样地(SAF1989)土壤羧基碳含量最高。(3)互花米草盐沼土壤中烷基碳/烷氧碳为:SAF2007(0.44)SSF1989(0.43)SAF2000(0.28)SAF2011(0.27)SAF1989(0.22);疏水碳/亲水碳为:SAF2007(0.97)SSF1989(0.87)SAF2000(0.85)SAF2011(0.83)SAF1989(0.81)。烷基碳/烷氧碳在建群5a后达到最高值0.44,烷基化程度最高;疏水碳/亲水碳达到最高值0.97,土壤碳库稳定性高于其它样地。     

赤霉素发酵溶氧优化调控研究

为了解溶氧对赤霉素发酵过程影响以及相应工艺优化,采用不同溶氧条件下藤仓赤霉菌Gibberella fujikuroi分批发酵生产赤霉素的过程进行菌丝浓度、残糖浓度和GA3产物浓度检测,并微分运算得出比生长速率与比产物合成速率随发酵时间变化,分析了溶氧对比生长速率与比产物合成速率以及得率的影响,进而提出Gibberella fujikuroi发酵高产的溶氧控制策略:在发酵初始阶段(0–50h)控制溶氧30%左右,以维持较高的菌体生长速率;发酵中后期(50–184h),溶氧控制在15%,以获取菌丝持续较高的GA3合成速率能力。采用这一优化溶氧控制策略,发酵过程中最大菌丝浓度19.24g/L、最终赤霉素浓度2 180mg/L和平均比产物合成速率0.616mg/(g·h),比未优化前发酵分别提高了8.33%、13.25%和4.58%,表明所采取的分阶段溶氧控制策略对促进GA3生产有效。     

Evaluation of “Classic” and Emerging Contaminants Resulting from the Application of Biosolids to Agricultural Lands: A Review

The presence of detectable amounts of contaminants in treated sewage sludge (concentrations μg/kg – mg/kg) has led to concerns that land applications of biosolids may result in an accumulation of contaminants in the soil and their subsequent translocation through the food chain. Despite advances in wastewater management (e.g., anaerobic, thermophilic, and mesophilic digestion), many compounds and their metabolites remain intact following treatment. This review looks at the main risk factors relating to the occurrence of “classic” (persistent organic pollutants [POPs]) and emerging pollutants (pharmaceuticals and personal care products) in biosolids. Relevant EU legislation and risk assessment strategies for the control of emerging contaminants are also considered. Organic pollutants regulated under the Stockholm Convention on POPs along with PPCPs were identified as contaminants of concern based on the risk factors: persistence, bioaccumulation, and toxicity (PBT). PPCPs were recognized as being of particular concern as their high transformation/removal rates are compensated by their continuous introduction into the environment. This study highlights the growing concern in relation to emerging contaminants in biosolids and highlights risk assessment strategies that can be used to characterize potential human/environmental risks.     

Organic compounds in re-circulated leachates of aerobic biological treated municipal solid waste

Biodegradation of organic matter is required to reduce the potential of municipal solid waste for producing gaseous emissions and leaching contaminants. Therefore, we studied leachates of an aerobic-treated waste from municipal solids and a sewage sludge mixture that were re-circulated to decrease the concentration of biodegradable organic matter in laboratory-scale reactors. After 12 months, the total organic C and biological and chemical oxygen demands were reduced, indicating the biodegradation of organic compounds in the leachates. Curie-point pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and pyrolysis-field ionization mass spectrometry (Py-FIMS) revealed that phenols, alkylaromatic compounds, N-containing compounds and carbohydrates were the predominate compounds in the leachates and solid waste. Leachate re-circulation led to a higher thermal stability of the residual organic matter as indicated by temperature-resolved Py-FIMS. Admixture of sewage sludge to solid waste was less effective in removing organic compounds from the leachates. It resulted in drastic higher and more bio-resistant loads of organic matter in the leachates and revealed increased proportions of alkylaromatic compounds. The biodegradation of organic matter in leachates, re-circulated through municipal solid waste, offers the potential for improved aerobic waste treatments and should be investigated on a larger scale.     

A quantitative risk ranking model to evaluate emerging organic contaminants in biosolid amended land and potential transport to drinking water

A quantitative risk ranking model was developed for human exposure to emerging contaminants (EC) following treated municipal sewage sludge (“biosolids”) application to Irish agricultural land. The model encompasses the predicted environmental concentration (PEC) in soil, surface runoff, groundwater, and subsequent drinking water ingestion by humans. Human exposure and subsequent risk was estimated for 16 organic contaminants using a Monte Carlo simulation approach. Nonylphenols ranked the highest across three environmental compartments: concentration in soil (PEC_soil), runoff (PEC_runoff), and groundwater (PEC_groundwater), which had mean values of 5.69 mg/kg, 1.15 × 10^?2 µg/l, and 2.22 × 10^?1 µg/l, respectively. Human health risk was estimated using the LC₅₀ (chemical intake toxicity ratio, (RR)) as a toxicity endpoint combined with PEC_runoff and PEC_groundwater. NP ranked highest for LC₅₀ combined with PEC_runoff and PEC_groundwater (mean RR values 1.10 × 10^?4 and 2.40 × 10^?3, respectively). The model highlighted triclocarban and triclosan as ECs requiring further investigation. A sensitivity analysis revealed that soil sorption coefficient and soil organic carbon were the most important parameters that affected model variance (correlation coefficient –0.89 and –0.30, respectively), highlighting the significance of contaminant and soil properties in influencing risk assessments. This model can help to prioritize emerging contaminants of concern requiring vigilance in environmental compartments.     

好氧反硝化微生物多样性及其反硝化功能初步研究

为研究污水厂/养殖池中好氧反硝化微生物的多样性及菌株反硝化能力,本研究采集了位于福建省厦门市和漳州市的污水处理厂、排污口、污水池、对虾养殖池的污水和污泥样品进行好氧反硝化微生物的富集、分离、鉴定和功能筛选。分别以NaNO3、NaNO2作为唯一氮源共分离纯化获得128株单菌。其中以NaNO3为唯一氮源分离得到63株,以NaNO2为唯一氮源分离得到65株。16SrRNA基因序列分析表明,128株单菌分属于γ-变形菌纲(Gammaproteobacteria,58.6%)、芽胞杆菌纲(Bacilli,6.4%)、放线菌纲(Actinobacteria,11.7%)、α-变形菌纲(Alphaproteobacteria,8.6%)、纤维菌纲(Cytophagia,2.3%)、鞘脂杆菌纲(Sphingobacteria,0.8%)和黄杆菌纲(Flavobacteria,1.6%)7个纲中的38个属。其中盐单胞菌属(Halomonas,29.7%)和芽胞杆菌属(Bacillus,12.5%)为优势菌属,并且广泛存在于各个样品中。反硝化功能初筛结果表明,35株菌能在72h内将20mg·L-1 NO-3-N/NO-2-N完全去除;复筛结果表明,21株菌能在72h内将100 mg·L-1 NO-3-N/NO-2-N完全去除,并且盐单胞菌属、卓贝尔氏菌属(Zobellella)、斯塔普氏菌属(Stappia)及节杆菌属(Arthrobactor)反硝化效果较好,其中斯塔普氏属是首次报道具有好氧反硝化功能。本研究结果表明,污水场/养殖池等环境中可培养反硝化细菌多样性丰富,同时高效反硝化菌的获得也为含氮废水的生物处理提供了良好的菌种资源。     

城市污泥农用对植物-土壤系统的影响

城市污泥的合理处置是目前资源与环境科学研究领域中的重要课题之一.城市污泥因富含大量的有机质和有效营养成分,对农业土壤肥力、土壤物理结构和农业生产均有一定的积极促进作用,使得污泥农用成为可能.但城市污泥中含有的重金属、有机污染物等有害物质尤其是重金属,成为污泥农用处置的瓶颈.为提高我国城市污泥的农业资源化利用效率和减少污染物造成的负面效应,本文就国内外施用城市污泥对植物-土壤互作系统的影响及过程进行了综述,为进一步提高污泥利用效率提供理论依据和科学指导.     

Anionic surfactants in treated sewage and sludges: risk assessment to aquatic and terrestrial environments

Compared to low concentrations of anionic surfactants (AS) in activated sludge process effluents (ASP) (<0.2 mg/L), upflow anaerobic sludge blanket-polishing pond (UASB-PP) effluents were found to contain very high concentrations of AS (>3.5 mg/L). AS (or linear alkylbenzen sulfonate, LAS) removals >99% have been found for ASP while in case of UASB-PP it was found to be < or = 30%. AS concentrations averaged 7347 and 1452 mg/kg dry wt. in wet UASB and dried sludges, respectively. Treated sewage from UASB based sewage treatment plants (STPs) when discharged to aquatic ecosystems are likely to generate substantial risk. Post-treatment using 1-1.6d detention, anaerobic, non-algal polishing ponds was found ineffective. Need of utilizing an aerobic method of post-treatment of UASB effluent in place of an anaerobic one has been emphasized. Natural drying of UASB sludges on sludge drying beds (SDBs) under aerobic conditions results in reduction of adsorbed AS by around 80%. Application of UASB sludges on SDBs was found simple, economical and effective. While disposal of treated UASB effluent may cause risk to aquatic ecosystems, use of dried UASB sludges is not likely to cause risk to terrestrial ecosystems.     

The biodegradation of surfactants in the environment

The possible contamination of the environment by surfactants arising from the widespread use of detergent formulations has been reviewed. Two of the major surfactants in current use are the linear alkylbenzene sulphonates (LAS) and the alkyl phenol ethoxylates (APE). These pass into the sewage treatment plants where they are partially aerobically degraded and partially adsorbed to sewage sludge that is applied to land. The biodegradation of these and a range of other surfactants both in wastewater treatment plants and after discharge into natural waters and application to land resulting in sewage sludge amended soils has been considered. Although the application of sewage sludge to soil can result in surfactant levels generally in a range 0 to 3 mg kg(-1), in the aerobic soil environment a surfactant can undergo further degradation so that the risk to the biota in soil is very small, with margins of safety that are often at least 100. In the case of APE, while the surfactants themselves show little toxicity their breakdown products, principally nonyl and octyl phenols adsorb readily to suspended solids and are known to exhibit oestrogen-like properties, possibly linked to a decreasing male sperm count and carcinogenic effects. While there is little serious risk to the environment from commonly used anionic surfactants, cationic surfactants are known to be much more toxic and at present there is a lack of data on the degradation of cationics and their fate in the environment.     

Effects of Sewage Sludge on the Growth of Potted Salt Marsh Plants Exposed to Natural Tidal Inundation

Abstract A growth experiment with native plants in pots exposed to natural environmental conditions evaluates the use of sewage sludge as a soil amendment in restoration of a southern California salt marsh. Sludge containing desirable organic matter but also undesirable heavy metal contaminants was mixed with a readily available matrix soil to reduce metal concentrations to levels below legal limits for land applications of sludge. Soil nutrient analysis revealed expected increases in total nitrogen and total phosphorus content with increasing sludge concentration. Soil metals analysis, however, revealed decreases in metal content with increased sludge concentration, a trend evidently caused by higher than expected metal content in the matrix soil. Five artificial soil mixtures ranging from 0 to 70% sludge were accompanied by natural wetland soil controls. Pots containing these soils were placed into a natural salt marsh. The pots were then planted with two native salt marsh plant species, Salicornia virginica and Frankenia grandifolia. Aboveground biomass was harvested after 12 months. Plant growth displayed no obvious change with increasing sludge concentration. Over the concentration ranges used, increased nutrient content did not stimulate plant growth and increased metal content did not inhibit plant growth. Plants grew better in natural wetland soil than in artificial soil mixtures, a trend probably caused by the substantially finer texture and higher organic content of natural soil. All sludge treatments differed more from the natural soil than from each other, implying that within the ranges examined, soil texture and organic content exerted more influence on plant growth than did metal or nutrient concentration. These results suggest that incorporating this sewage sludge in the soil of the restored salt marsh will neither benefit nor harm the plants that will live there and that greatest plant growth will be achieved by mixing the sludge with a fine‐grained matrix soil.     

不同类型土壤小麦-水稻轮作体系施用含重金属污泥的环境效应

采用贵州黄壤、石灰土和浙江水稻土,通过盆栽试验探讨了在3种土壤上施用含不同浓度重金属的污泥对小麦、水稻生长及锌(Zn)镉(Cd)吸收性的影响.结果表明： 不同土壤施用同种污泥所产生的重金属污染风险不同,在黄壤和水稻土上施用高浓度重金属污泥对作物的污染风险较高.一次施用Zn、Cd浓度分别为1789、8.47 mg·kg-1的污泥1.6%,使黄壤小麦籽粒中Zn、Cd浓度分别达109、0.08 mg·kg-1;第二次施用后种植水稻,糙米中Zn、Cd浓度达52.0、0.54 mg·kg-1.而施用污泥后石灰性土壤的两种作物其可食部分均无重金属污染风险.土壤醋酸铵提取态Zn是影响麦粒和糙米中Zn浓度的主要因素,而土壤醋酸铵提取态Cd对麦粒和糙米中Cd浓度无明显影响.施用高浓度重金属污泥使3种土壤Zn、Cd全量显著提高,且两次施用后土壤全量Zn均超过国家土壤环境质量二级标准.