两次投加竹炭对UASB反应器污泥颗粒化的促进作用

为考察竹炭不同投加方式对UASB反应器污泥颗粒化过程的影响,以猪场废水为培养基质,对比分析了试验组（启动初期和颗粒污泥形成后两次投加粉末竹炭）和对照组（仅在启动初期投加1次粉末竹炭）两台UASB反应器中污泥颗粒化过程。结果表明：在颗粒污泥出现后再次投加粉末竹炭可促进颗粒污泥的增殖与稳定,有利于大粒径颗粒污泥的形成和致密化,改善颗粒污泥沉降性能,进而提高有机物去除效果。试验运行至第57 天,试验组反应器底部和上部污泥颗粒化程度（SGR）分别为94.5%和60.7%,比对照组分别高出了7.9%和17.3%,其中试验组反应器底部粒径大于 1.7 mm的颗粒污泥质量分数达到了41.7%,而对照组仅为32.4%;试验组反应器化学需氧量（COD）去除率为81.6%,明显高于对照组（75.7%）。试验结果证明,在UASB污泥颗粒化过程中,于颗粒污泥出现后再次投加粉末竹炭,可加快UASB 反应器的启动。     

好氧颗粒污泥的研究新进展

好氧颗粒污泥是近年发现的,在好氧条件下自发形成的微生物细胞之间自身固定化的一种形式,具有良好的沉降性能、较高的生物量和在高容积负荷条件下降解高浓度有机废水的良好生物活性.污泥颗粒化过程是一个多阶段的过程,取决于废水组成、操作条件和适当的选择压等因素.COD和DO浓度对好氧颗粒污泥的同步硝化反硝化反应有明显影响.COD浓度在400～1200mg/L范围内,好氧颗粒污泥去除COD的能力均在85%以上.颗粒污泥能吸附有机物,使废水中COD浓度快速下降.COD浓度＜800mg/L,,好氧颗粒污泥具有良好的脱N能力,N去除率最高达85.3%.在溶氧浓度为1～4 mg/L条件下,颗粒污泥对COD去除率均在90%以上.不同的溶氧浓度对N的去除率有一定影响,在溶氧浓度3mg/L时,N去除率最高,达83%.本文对好氧颗粒污泥的基本特征和微生物相、好氧颗粒污泥形成的主要影响因素及其颗粒化反应器等进行综述,并对好氧颗粒污泥在环境工程中的进一步应用提出展望.     

农业废弃物两相厌氧处理技术的研究

以两只750ml UASB反应器分别作为酸化相和甲烷相进行农业废弃物厌氧处理的研究,两相中,都培养出了颗粒污泥。酸化相有机负荷达240kgCOD/m~3[bed]·d,HRT=1.6h,酸化率66％,COD去除率4％～8％,甲烷相有机负荷达88kgCOD/m~3[bed]·d,HRT=3.7h,COD去除率大于85％。两相COD总去除率大于90％,总有机负荷60kgCOD/m~3[bed]·d。并结合扫描电镜照片,对两相颗粒污泥的形成,菌体分布规律等进行了探讨。     

脉冲循环式渠槽厌氧反应器处理太湖腐熟蓝藻性能

为实现太湖腐熟蓝藻的资源化处理,研究新型厌氧反应器——脉冲循环式渠槽厌氧反应器处理太湖腐熟蓝藻的效能及其运行特点。以城市污水处理厂剩余污泥为种泥,污泥接种量混合液挥发性悬浮固体浓度(MLVSS)为20g/L,进水化学需氧量(COD)质量浓度2000mg/L,水力停留时间(HRT)为5d,中温(30～35℃)厌氧条件下,反应器可在30d内成功启动并达到初步稳定运行,COD去除率达到60%左右,产气率为0.08L/(L·d);当进水COD容积负荷3.5kg/(m3·d)时,仍能实现安全稳定运行,COD去除率可以稳定在80%左右,产气率在1.2L/(L·d),表明反应器抗冲击负荷能力较强,同时沼液中藻毒素(TMC-LR、EMC-LR)去除率为90%以上。稳定运行期间反应器厌氧颗粒污泥对腐熟蓝藻甲烷化的最大比基质降解速率为1.253mg/(mg·d),半饱和常数为11770mg/L,甲烷产率系数为0.256mL/mg;电镜观测发现稳定运行期颗粒污泥以产甲烷的八叠球菌为主,伴有丝状菌和杆菌等,同时发现其蛋白酶、TTC-脱氢酶和辅酶F420活性相对较高。研究发现脉冲循环式渠槽厌氧反应器能够有效地处理太湖蓝藻,这对其资源化利用具有一定的指导意义。     

猪场废水生化处理工艺研究

针对猪场废水有机物、氮、磷含量高的特征，应用上流式厌氧污泥床(UASB)和序批处理反应器(SBR)相结合废水处理工艺，研究了不同水力负荷条件下对COD、BOD、氨氮去除率的影响。研究结果表明，在COD 2～8 kg/(m³·d)条件下，COD的去除率在60%～73%之间，效果较稳定；SBR在去除氨氮中效果十分明显，去除率达80%～95%。     

杭州灯塔养殖总场猪粪污水处理工程的设计与运行

采用厌氧—好氧(UASB—SBR)法处理技术对杭州灯塔养殖总场的高浓度猪粪污水进行处理，COD总去除率达98%，NH₃-N去除率达99%以上，出水COD浓度不大于150 mg/L ，NH₃-N浓度不大于15 mg/L，出水水质达到《污水综合排放标准》(GB8978-1996)的二级排放标准。     

两种厌氧反应器培养颗粒污泥的对比试验

以养猪场废水作为试验用水，对在IC和UASB反应器内培养厌氧颗粒污泥的过程进行了对比试验，并对培养出的颗粒污泥的特性进行了对比分析。结果表明：经过54d培养，通过不同孔径的筛网进行测试，发现IC反应器内形成的颗粒污泥的直径多数在1～4 mm之间，其中2～3 mm的污泥质量占污泥总质量的比例最大，为28.5％，并且有大于5 mm的颗粒污泥产生；而UASB内形成的颗粒污泥直径多数在1～3 mm之间，其中1～2 mm的污泥质量占污泥总质量的比例最大，为38.7％，且没有发现大于5 mm的颗粒污泥。     

膜生物反应器处理猪场污水研究

为探讨膜生物反应器(MBR)处理猪场污水的可行性和膜生物反应器的运行、操作条件,为膜生物反应器在处理猪场污水中的应用提供必要的基础参数,该文采用U型中空纤维膜和L式中空纤维膜生物反应器,对不同的化学需氧量(COD)及氨氮(NH⁺₄-N)进水浓度、溶解氧水平(DO)、污泥龄(SRT)进行了4种工况试验研究。结果表明,MBR作为猪场污水处理好氧段是可行的,当进水COD平均浓度为1860 mg/L,U型、L式膜平均去除率分别为84.10％,81.20％;NH⁺₄-N进水平均浓度为511 mg/L,U型、L式膜平均去除率分别为93.81％,93.61％。     

Na+和K+共存对A2/O工艺脱氮除磷效果及污泥性质的影响

为了揭示多种金属离子共存的含盐废水生物处理系统污染物的去除机制和污泥特性,考察Na~+、K~+共存对A~2/O工艺污染物去除率、污泥性质和微生物群落的影响,采用高通量测序技术分析了厌氧区、缺氧区和好氧区的微生物群落结构,结合脱氮除磷效果和污泥性质的变化,探讨不同Na~+/K~+摩尔比下A~2/O工艺优势种群的演替规律,以期从微生物角度明确Na~+、K~+共存对含盐废水污染物去除率的影响。结果表明:当进水Na~+/K~+摩尔比分别为2、1和0.5时,A~2/O工艺的COD去除率分别为80%、84%和86%,TN去除率分别为73%、77%和80%,K~+浓度的提高缓解了Na~+对COD和TN去除率的抑制作用;厌氧区释磷率分别为70%、73%和74%,缺氧区吸磷率分别为53%、55%和58%,好氧区吸磷率分别为70%、72%和75%。随着进水Na~+/K~+摩尔比的降低,厌氧区、缺氧区和好氧区微生物群落的丰富度和多样性降低,微生物群落差异显著,变形菌门的相对丰度均升高约30%,拟杆菌门和绿弯菌门相对丰度逐渐降低。陶氏菌属和固氮弧菌属作为优势菌属,其相对丰度逐渐增大,有利于氮磷污染物的去除。通过增加K~+的浓度有利于提高氮、磷去除率,增强污泥的生物絮凝性和反硝化聚磷菌的活性。     

农业废弃物两相厌氧处理技术的研究

以两只750mlUASB反应器分别作为酸化相和甲烷相进行农业废弃物厌氧处理的研究,两相中,都培养出了颗粒污泥。酸化相有机负荷达240kgCOD/m³[bed]·d,HRT=1.6h,酸化率66％,COD去除率4％～8％,甲烷相有机负荷达88kgCOD/m³[bed]·d,HRT=3.7h,COD去除率大于85％。两相COD总去除率大于90％,总有机负荷60kgCOD/m³[bed]·d。并结合扫描电镜照片,对两相颗粒污泥的形成,菌体分布规律等进行了探讨。     

Interaction of Magnesium–Iron–Carbonic-Layered Double Hydroxides with As(III)

Static granular bed reactor (SGBR) and upflow anaerobic sludge blanket (UASB) reactor were demonstrated at mesophilic condition for the treatment of pulp and paper mill wastewater. The hydraulic retention times (HRTs) were varied from 4 to 24 h following 29-day start-up period. The overall chemical oxygen demand (COD) removal efficiency of the SGBR was higher than the UASB during this study. At 4 h HRT, the COD removal was greater than 70 % for the SGBR and 60 % for the UASB. Biomass yield and volatile fatty acids concentration of SGBR were slightly less than UASB at organic loading rates ranging from 1.2 to 5.1 kg/m³/day. The results indicated that the SGBR system can be considered a viable alternative system for anaerobic treatment for pulp and paper wastewater.     

Dewatered anaerobically‐stabilized primary sewage sludge composting: Metal leachability and uptake by natural Clinoptilolite

Abstract

Environmental problems associated with sewage sludge disposal have prompted strict legislative actions over the past years. At the same time, the upgrading and expansion of wastewater treatment plants have greatly increased the volume of sludge generated. The major limitation of land application of sewage sludge compost is the potential high heavy metal content in relation to the metal content of the original sludge. Composting of sewage sludge with natural zeolite (Clinoptilolite) can enhance its quality and suitability for agricultural use. Clinoptilolite has the ability to uptake heavy metals in satisfactory levels. Finally, in order to estimate the metal leach ability of the final product of compost, the Generalized Acid Neutralization Capacity (GANC) procedure was used and was found that by increasing the leachate pH, the heavy metal concentration decreases.     

Electrokinetic Copper and Iron Migration in Anaerobic Granular Sludge

The application of low-level direct electric current (0.15 mA cm^?2) as an electrokinetic technique to treat copper-contaminated mesophilic anaerobic granular sludge was investigated. The sludge was obtained from a full scale UASB reactor treating paper-mill wastewater and was artificially contaminated by Cu(NO₃)₂ or CuEDTA^2? with initial copper concentrations of 1000 mg . kg^?1 wet sludge. The effect of different electrokinetic cell layouts, pH and EDTA concentrations on the migration of copper and iron during electrokinetic treatment were evaluated. Both, the pH of the sludge cake or the copper complexation with EDTA significantly affected the migration direction of copper. In an ‘open’ cell (sludge cake in direct contact with air), the highest copper mobility was observed at pH 2.5 in both Cu(NO₃)₂ or CuEDTA^2? amended sludge. The highest copper accumulation was at the cathode (22 ± 2)% with CuEDTA^2? as contaminant. In a ‘closed’ cell (sludge cake not in contact with air), the highest accumulation was obtained for CuEDTA^2? at the anode and amounted to 4(± 0.5)% and 2(± 0.05)%, respectively, at a final pH of 4.2 and 7.7 in the sludge cake.     

Hydraulic Retention Time Influence on Improving Flocculation in the Activated Sludge Processes Through Polyelectrolytes

Hydraulic retention time (HRT) influence improving sludge flocculation with adding the polyelectrolytes (non-ionic, anionic, and cationic) was studied on an activated sludge (AS) system fed with synthetic domestic wastewater (SDW), dairy industry wastewater (DIW), and caramel industry wastewater (CIW). The sludge volumetric index, food/microorganism ratio (F/M), and mixed liquor volatile suspended solids at different HRTs (6, 8 and 10 h) were monitored on an experimental model. Results showed that both SDW and IW had the best sludge flocculation conditions at 8 h and 100 mL of non-ionic polyelectrolyte (0.2 mg L^?1). In addition, this phenomenon reached the organic matter removal efficiencies of 95.9, 95.7, and 94.2% for SDW, DIW, and CIW, respectively. Therefore, optimum HRT increased the organic matter removal efficiencies by 10%, sludge concentration by 37% (22–55%), and F/M ratio by 70%. Moreover, the polyelectrolytes used in AS improved the sludge flocculation by 2.9 times.     

Pseudomonas putida GM6在活性污泥中的生物强化除磷

The enhanced biological phosphorus removal （EBPR） method is widely adopted for phosphorus removal from wastewater, yet little is known about its microbiological and molecular mechanisms. Therefore, it is difficult to predict and control the deterioration of the EBPR process in a large-scale municipal sewage treatment plant. This study used a novel strain isolated in the laboratory, Pseudomonas putida GM6, which had a high phosphate accumulating ability and could recover rapidly from the deteriorated system and enhance the capability of phosphorus removal in activated sludge. Strain GM6 marked with gfp gene, which was called GMTR, was delivered into a bench-scale sequencing batch reactor （SBR） of low efficiency, to investigate the colonization of GMTR and removal of phosphorus. After 21 days, the proportion of GMTR in the total bacteria of the sludge reached 9.2%, whereas the phosphorus removal rate was 96%, with an effluent concentration of about 0.2 mg L^-1. In the reactor with the addition of GMTR, phosphorus was removed quickly, in 1 h under anaerobic conditions, and in 2 h under aerobic conditions. These evidences were characteristic of EBPR processes. Field testing was conducted at a hospital sewage treatment facility with low phosphorus removal capability. Twentyone days after Pseudomonas putida GM6 was added, effluent phosphorus concentration remained around 0.3 mg L^-1, corresponding to a removal rate of 96.8%. It was therefore demonstrated that Pseudomonas putida GM6 could be used for a quick startup and enhancement of wastewater biological phosphorus removal, which provided a scientific basis for potential large-scale engineering application.     

Plant availability of phosphorus from dewatered sewage sludge,untreated incineration ashes,and other products recovered from a wastewater treatment system

The objective of the present study was to evaluate the plant phosphorus (P) availability of products derived from new P‐recovery technologies deployed in wastewater treatment systems against sewage sludge and untreated sewage sludge ashes. Eight P sources were evaluated in a six‐week pot experiment with spring barley (Hordeum vulgare L.) and a soil incubation experiment with anaerobically digested and dewatered sewage sludge (Sludge), sewage sludge ash (Ash), thermochemically treated sewage sludge ash (TrAsh), struvite (Struv), concentrate (Conc), and centrifuged concentrate (Prec) from evaporated reject water, with triple super phosphate (TSP), and composted organic household waste (Comp) as references. All sludge‐related materials except struvite came from the same wastewater treatment plant in Denmark. The apparent plant P use efficiency (PUE) of the treatments in the pot experiments was in the following order: Prec (17.0%) > TSP (12.8%) ≥ Conc (12.7%) > Sludge (8.8%) ≥ TrAsh (6.9%) ≥ Struv (6.0%) ≥ Comp (5.8%) > Ash (3.4%). The water‐extractable P (WEP) in the incubation experiment largely supported this order and there was a strong correlation between WEP in the incubation experiment and plant P uptake in the pot experiment. Overall, the results of this study demonstrate that it should not automatically be assumed that products recovered with new treatment technologies for P recovery are more effective P fertilizers than the sewage sludge from which they originate. Furthermore, these results indicate that the measurement of water‐extractable P after soil incubation could be a suitable proxy for plant P availability.     

Assessment of Cryptosporidium Removal from Domestic Wastewater Via Constructed Wetland Systems

Constructed wetlands have been recognized as offering a removal treatment option for high concentrations removal of chemical and biological contaminants in domestic wastewater. The enteric protozoan parasite Cryptosporidium is considered one of the highly resistant to treatment and highly infectious organisms to humans and animals. Moreover, some species of Cryptosporidium are known to have a zoonotic nature. In this investigation a pilot scale for domestic wastewater treatment system was used, consisting of the following steps in series: (1) up-flow anaerobic sludge blanket (UASB) reactor, (2) free water surface (FWS) wetland unit, and (3) sub-surface flow (SSF) wetland unit. This treatment system was fed with domestic wastewater to assess its efficiency in removing Cryptosporidium oocysts. The obtained Cryptosporidium oocysts were detected and enumerated by two different staining techniques ‘acid fast trichrome (AFT) and modified Ziehl Neelsen (MZN) stains’. Polymerase chain reaction (PCR) technique was also used to detect Cryptosporidium DNA in wastewater samples. Results revealed that anaerobic treatment (using UASB reactor) could remove about 53.1% of Cryptosporidium oocysts present in raw wastewater. The in-series connection between the two wetland units allowed complete elimination of Cryptosporidium oocysts as the first (FWS) wetland unit removed 95.9% of the oocysts present in anaerobically treated wastewater and the remaining portion of oocysts was completely removed by the second (SSF) wetland unit. Cryptosporidium oocysts were detected in 95.8% of raw wastewater samples with a mean count of 43.8 oocysts/l when AFT stain was used while they were detected in only 87.5% of raw wastewater samples with a mean count of 35.6 oocysts/l when MZN stain was used. Polymerase chain reaction (PCR) technique was able to detect Cryptosporidium DNA in only 45.8% of raw wastewater samples. Positive PCR results were only achieved in wastewater samples containing 52 oocysts or more per liter.     

城市污泥的污染现状及其土地利用评价

随着城市污泥产生量的迅速增加,污泥的科学处置及土地利用是当前城市固体废弃物资源化的主要研究内容。本文较系统地阐述了污泥的基本性质、污泥污染和处置现状及土地利用的风险评价等相关研究,并指出了目前城市污泥研究中存在的问题。     

Effects of thermal drying on phosphorus availability from iron‐precipitated sewage sludge

Thermal drying of sewage sludge implies sanitation and improves practical handling options of the sludge prior to land application. However, it may also affect its value as a fertilizer. The objective of this study was to assess whether thermal drying of sewage sludge, as well as drying temperature, affects plant P availability after application to soil. The experiment included dewatered sewage sludge (20% DM) and thermally dried sewage sludge (95% DM) collected at a Danish wastewater treatment plant, as well as laboratory oven‐dried (70, 130, 190, and 250°C; DM > 95%) subsamples of the dewatered sludge, and a triple superphosphate as a reference. Plant P availability was studied in a 197 d soil incubation experiment, with sampling for Diffusive Gradients in Thin films (DGT) and water extractable P (WEP) analyses over time, and in a pot experiment with spring barley (Hordeum vulgare L.). In both experiments, thermal drying reduced P availability, as shown by 37 and 23% lower DGT and WEP values, respectively, and a 16% lower P uptake by barley in the pot experiment. The specific drying temperature did not appear to have much effect. Overall, our results suggest that thermal drying of iron‐precipitated sewage sludge is not an optimal treatment option if the aim is to optimize plant P availability.