垃圾渗滤液微生物循环接种强化堆肥碳素和氮素迁移

以城市生活垃圾为堆肥原料,进行了20d的垃圾渗滤液微生物循环接种强化堆肥试验,堆肥过程中采用时间温度反馈来控制通风量,力图通过测定堆肥体系中碳素以及凯氏氮、氨氮、硝态氮含量的动态分布,分析碳素和氮素的迁移转化规律.试验结果表明:采用垃圾渗出液微生物循环接种强化技术的堆肥体系接种组温度可维持在较高水平,pH可稳定在7.0左右,有机质降解加快,对碳素和氮素的形态分析表明:对照组总有机碳和碳氮比波动较大,而接种组下降趋势更为明显,高温条件下的氨气挥发是导致氮素损失的主要原因.     

垃圾渗滤液微生物循环接种强化堆肥碳素和氮素迁移

以城市生活垃圾为堆肥原料，进行了20d的垃圾渗滤液微生物循环接种强化堆肥试验，堆肥过程中采用时间温度反馈来控制通风量，力图通过测定堆肥体系中碳素以及凯氏氮、氨氮、硝态氮含量的动态分布，分析碳素和氮素的迁移转化规律。试验结果表明：采用垃圾渗出液微生物循环接种强化技术的堆肥体系接种组温度可维持在较高水平，pH可稳定在7．0左右，有机质降解加快，对碳素和氮素的形态分析表明：对照组总有机碳和碳氮比波动较大，而接种组下降趋势更为明显，高温条件下的氨气挥发是导致氮素损失的主要原因。     

接种硝化菌剂降低猪粪堆肥氮素损失的研究

[目的]降低猪粪堆肥中由于NH<,3>释放造成的氮素损失,为堆肥反应确定初始条件、工艺优化提供理论依据.[方法]用猪粪与粉碎的稻草按比例混合堆肥,用接种硝化菌剂方法研究猪粪堆肥的固氮效果.[结果]通过试验,确定最佳工艺条件为:硝化菌剂接种量为3%,初始pH为7.0,初始含水量为65%,前半周期的通气量为150 L/min,后半周期的通气量为100 L/min.[结论]堆肥前期NH<,3>释放量的控制是氮素损失控制的关键.在适宜的工艺条件下,堆肥腐熟后的TN损失率为31.8%,氮素物质损失率降低幅度明显.     

正交试验优化发酵中氨气释放条件的研究

[目的]为降低发酵过程中氨气释放及氮素损失,在室内条件下对城市生活垃圾进行好氧发酵研究.[方法]利用正交试验设计研究初始条件对发酵过程中氨气释放的影响,优化发酵过程氨气释放条件.[结果]正交试验结果表明,初始C/N和环境温度对氨气释放影响最为显著;最佳发酵工艺参数组合为:含水率60%,C/N为40:1,pH值7.0, 温度25℃.[结论]该研究为降低发酵过程氮的损失、减少空气污染提供了理论依据.     

陈腐垃圾填埋场腐殖土好氧堆肥-浸提技术工艺研究

以某生活垃圾填埋场腐殖土为研究对象,采用好氧堆肥-浸提技术进行腐殖土中可溶性盐类、有机质、重金属的有效处理,探究不同C/N比、微生物菌液添加量、浸提剂添加比例、浸提时间下腐殖土的处理效果,确定最优的好氧堆肥-浸提技术工艺条件。结果表明:调节腐殖土中C/N为25∶1后,添加45 L微生物菌液,保持好氧堆肥条件后,以1∶1体积比添加浸提剂,浸提8 h,反复两次后,再用清水浸提一次,处理后腐殖土能满足《绿化种植土壤》(CJ/T 340-2016)标准。     

东乡普通野生稻根际微生物群落特征研究

[目的]研究东乡普通野生稻(Oryza rifipogon Griff.)根际微生物群落特征.[方法]采用氯仿熏蒸浸提法测定根系微生物生物量碳、氮;采用平板稀释培养法测定群落组成;采用最大或然计数法测定微生物生理群.[结果]东乡野生稻根际微生物生物量碳、氮平均值分别为83.02和16.98mg/kg(土),较普通栽培稻低;根际可培养微生物中细菌>放线菌>真菌;氮素生理群中氨化细菌>好氧固氮菌>反硝化细菌>嫌气性固氮菌>硝化细菌>亚硝化细菌.[结论]东乡野生稻根际微生物群落组成与普通栽培稻相比有差异.     

生物垃圾堆肥的影响因素及反应动力学研究

[目的]为有效控制生活垃圾堆肥过程、提高堆肥效率提供理论依据.[方法]利用堆肥反应动力学,以含水率、堆料颗粒大小、压实度、通气量作为研究对象,建立动力学模型,通过堆肥一次发酵试验,研究舍水率、颗粒度、压实度、通风量时生活垃圾堆肥过程中有机物降解及堆肥反应速率的影响.[结果]当含水率为65%,堆料颗粒大小为8 cm,压实度0.247 kg/L,通气量25 m<'3>/(h·t)时堆肥反应速率较大.[结论]生活垃圾堆肥反应符合一级反应动力学.     

污泥堆肥应用于废弃金属矿山表土基质改良的研究

利用城镇污水处理厂污泥好氧堆肥产物与废弃矿山表土进行掺混开展盆栽试验，通过对土壤基本理化性质、植物生长情况、土壤酶活性以及微生物含量的分析，研究了城镇污水厂污泥应用于矿山表土改良的可行性。结果显示，在20%的污泥堆肥掺混比例下，与原废弃矿山表土相比，有机质含量提升了4.4倍，土壤全氮含量提升了9.5倍。因此，污泥堆肥可以显著的提升矿山表土的肥力，有效地改善土壤微生物数量与酶的活性，促进植物的生长和生态恢复。     

V微合金化对高强高耐候乙字钢性能的影响

以中频感应炉冶炼不同钒、氮含量试验钢为材料,通过力学性能检验和析出相分析,研究了钒微合金化对高强高耐候乙字钢性能的影响。结果表明:钒在高强高耐候乙字钢中能起到细晶强化或沉淀强化的作用,而氮的加入可促使钒从固溶态向析出态转化,增大钒的析出强化作用。终轧温度对钒氮的析出强化作用敏感,终轧温度越低,V(C,N)的析出量越大,屈服强度越高,但强塑性匹配最好的终轧温度在850℃左右。     

黑麦草-根内球囊霉联合修复铀污染土壤

针对铀矿周边土壤污染修复问题,植物-微生物联合修复技术具备高效性、环保性优点,能有效解决土壤污染问题而受到人们广泛关注。根内球囊霉(Glomus intraradice,Gi)可与大多数植物形成互利共生的关系,利用Gi接种黑麦草根部修复铀污染土壤。设置Gi接种黑麦草根部与未接种组对照,在不同浓度(18.74、52.15、112.40、202.40mg/kg)铀污染土壤进行修复模拟,探究Gi对黑麦草修复铀污染土壤的强化过程。结果表明,所有铀处理组接种Gi的菌根侵染率均大于50%;生物量显著提升,202.40mg/kg铀处理组中黑麦草地上部分、根部的生物量提升幅度达86%、136%;铀含量、生物富集系数以及吸收氮、磷、钾元素含量均显著提升,但转运系数均低于未接种处理组,说明Gi增强植物根部对铀的富集固定作用,抑制铀由根部向茎叶转移。综上所述,Gi可以增加宿主植物对铀金属毒性的抗逆能力,强化铀污染土壤的植物根部对铀的固定过程,有效提高黑麦草对铀的富集能力。     

Treatment of Leachate by Aged-Refuse-based Biofilter

Refuse in landfills becomes stabilized or aged, as organic matter in the refuse gradually degrades and as the soluble inorganic substances dissolve during its long-term stabilization process. Within this paper, this process is referred to as mineralization and the resultant stabilized or essentially stabilized refuse is referred to as “aged refuse.” The aged refuse contains a wide spectrum and large quantity of microorganisms, which have a strong decomposition capability for refractory organic matter present in some wastewaters, such as leachate. In this study, aged refuse excavated from two to ten year old closed landfill compartments in Shanghai Refuse Landfill (SRL) was characterized in terms of particulate distribution by screening, and a biofilter consisting of ten year old aged refuse was then used for biofiltration of leachate sampled from the landfill. Typically, 400 kg of screened aged refuse with limiting diameter less than 15 mm was used as biofiltration materials in a round shaped biofilter with 80 cm inner diameter and 80 cm height. Leachate with initial chemical oxygen demand (COD), biological oxygen demand (BOD), and NH3–N concentrations of 3,000–7,000, 540–1,500, and 500–800 mg/L, respectively, was passed through the biofilter. As a result, the corresponding concentrations in the effluent were reduced to lower than 100–350, 10–200, and 10–25 mg/L, respectively, 90–99% removal for these parameters at a hydraulic load of 80–200 L/m3 refuse/day. The color of the effluent became slightly gray, in comparison with the heavy brownish color of the influent. The treatment efficiencies heavily depend on hydraulic load, BOD/COD ratios in the leachate, and preliminary treatment of the aged refuse. A variety of leachates with various BOD/COD ratios was tested. It was found that the effluent deteriorated when BOD/COD ratios were lower than 0.1–0.2. Increase of hydraulic load resulted in a decrease of removal efficiencies. Removal of stone, plastics, and glass, etc., from the aged refuse improved the treatment. A pilot test was conducted at SRL and the experimental results obtained at laboratory scale were verified.     

Simulation of Construction and Demolition Waste Leachate

Solid waste produced from construction and demolition (C&D) activities is typically disposed of in unlined landfills. Knowledge of C&D debris landfill leachate is limited in comparison to other types of wastes. A laboratory study was performed to examine leachate resulting from simulated rainfall infiltrating a mixed C&D waste stream consisting of common construction materials (e.g., concrete, wood, drywall). Lysimeters (leaching columns) filled with the mixed C&D waste were operated under flooded and unsaturated conditions. Leachate constituent concentrations in the leachate from specific waste components were also examined. Leachate samples were collected and analyzed for a number of conventional water quality parameters including pH, alkalinity, total organic carbon, total dissolved solids, and sulfate. In experiments with the mixed C&D waste, high concentrations of total dissolved solids (TDS) and sulfate were detected in the leachate. C&D leachates produced as a result of unsaturated conditions exhibited TDS concentrations in the range of 570–2,200 mg∕L. The major contributor to the TDS was sulfate, which ranged in concentration between 280 and 930 mg∕L. The concentrations of sulfate in the leachate exceeded the sulfate secondary drinking water standard of 250 mg∕L. The leachate produced from lysimeters exposed to conditions of constant flooding possessed a greater concentration of dissolved constituents than leachate from the unsaturated lysimeters. The sulfate concentration ranged from 950 to 1100 mg∕L. In both scenarios, the primary ions contributing to the dissolved solids were sulfate and calcium, both a result of gypsum drywall. The flooded lysimeters remained at a constant pH of 11 throughout the experiment, whereas the pH dropped to neutral conditions (pH 6–7) in the unsaturated columns after 1 month of the leaching experiment. The high pH of leachate from the flooded columns was attributed to concrete. Based on leaching tests on individual waste components, wood and cardboard were the primary materials contributing to dissolved organic carbon. The organic carbon concentrations in the leachate were generally lower than typical municipal waste leachate. The biological conversion of sulfate to sulfide was evident in many columns, and was most pronounced in the unsaturated, mixed-waste columns.     

FeC内电解处理渗滤液尾水研究

根据FeC对难降解物质具有一定的还原作用,并对部分物质具有去除COD的功效,应用FeC内电解技术对经矿化垃圾生物反应床处理后渗滤液尾水进行深度处理研究,通过FeC比例、pH条件、反应时间等不同因素的小型试验确定其适宜条件,并通过L9(34)正交试验,确定如下最佳条件,反应时间5h,pH为6,FeC比例为4:1,此时出水COD能降低约100 mg/L,而对氨氮其作用不大,甚至有增加的趋势,FeC内电解反应后出水的pH值和电导率具有一定的增加趋势。     

Pilot-Scale Simulation of Landfill Bioreactor and Controlled Dumping of Fresh and Partially Stabilized Municipal Solid Waste in a Tropical Developing Country

Four pilot-scale lysimeters were used to study the benefits of landfill operation with and without leachate recirculation in tropical weather conditions. Young and old landfills were simulated by filling lysimeters with a segregated fraction of fresh municipal solid waste (MSW) and MSW mined from an open dump site, respectively, and periodically monitoring leachate quantity and quality and biogas quality. For each substrate, one lysimeter was operated as a bioreactor with leachate recirculation and another lysimeter was operated as a controlled dump, for a period of 10 months. Densities between 652 and 825??kg/m3 could be achieved with fresh and mined MSW. Despite such compaction during waste placement, bioreactor technology helps in leachate management, especially in the case of the young landfill lysimeter operated in tropical weather. The benefits of leachate recirculation in the young landfill lysimeter were evident from the significant decrease in chemical oxygen demand (COD) (86%), biochemical oxygen demand (BOD) (82%), dissolved organic carbon (DOC) (85%), and volatile solids (75%) in leachates. However, ammonia nitrogen (amm-N) and chlorides in the leachates accumulated in bioreactor landfills. Operating an old landfill lysimeter as a bioreactor seemed to have no exceptional advantage in the context of leachate management, although leachate recirculation enhanced the methane potential of both fresh and mined MSW.     

Performance of a Combined Natural Wastewater Treatment System in West Texas

A study of performance of a combined natural wastewater treatment system was conducted in an arid and semiarid area of West Texas from October 2005 to September 2007. This study investigated the organic matter and nitrogen removal capability in a municipal wastewater land application system following a pond system. Municipal wastewater from the city of Littlefield, Tex. was pretreated by a pond system, and the secondary wastewater effluent from the pond system was surface applied to sprayfield at the wastewater treatment plant and the city farm. The 16 lysimeters were installed in situ to collect the leached water passing the grass root zone. The water samples were taken from the storage pond and the lysimeters for analysis of chemical oxygen demand (COD), total nitrogen, nitrate nitrogen, and ammonia nitrogen. The data show that the pond system played an important role in the treatment. The pond system pretreated COD in the municipal wastewater to the range of 10 to 127 mg/L, total nitrogen to the range of 5 to 19 mg/L, nitrate nitrogen to the range of 2.4 to 8.2 mg/L, and ammonia nitrogen to the range of 0.01 to 6.4 mg/L. The average mass removals and cumulative mass removals were 94 and 96% for total nitrogen, 92 and 93% for nitrate nitrogen, and 96 and 100% for ammonia nitrogen, respectively. There was no potential nitrogen contamination to groundwater found during the research period. The study illustrated that this type of combined natural wastewater treatment system can be used to effectively treat and safely dispose municipal wastewater, and save freshwater used for agricultural irrigation in arid and semiarid area.     

Natural Freezing, Drying, and Composting for Treatment of Septic Sludge

A full-scale experimental plant intended for local treatment of septic sludge, situated in northern Sweden, is presented in this paper. The concept investigated included natural freezing, thawing, and drying in combination with composting. The experimental plant consisted of an undrained freezing-thawing-drying bed and a heat-insulated composter. About 500 L of fresh sludge, with a dry matter (DM) content of 4–5%, collected from a septic tank employed by one family, was transferred to the freezing-thawing-drying bed in the beginning of November 1996. During the winter months, the sludge froze and then thawed in the middle of May 1997. During a drying period of three weeks, the DM content increased from 10.6–21.3 to 25–95%. The final sludge volume and weight were 180 L and 54 kg, respectively. Approximate concentrations of nitrogen, phosphorus and total organic carbon of the dried sludge were determined to be 23, 5.9, and 346 g∕kg DM. From June until the end of August, the sludge was cocomposted with kitchen refuse. Within two weeks, the composting temperature exceeded 65°C. The measured composting temperature indicated a high pathogen die-off, but before this concept can be suggested as an alternative to conventional septic sludge treatment, further studies should be conducted, including direct measurements of pathogens. The concept, however, has proved to be of interest in cold regions due to its simple construction and operation.     

矿化垃圾在土壤修复中的应用前景

综述了垃圾堆场渗滤液、垃圾填埋气体以及垃圾残留固体可能对土壤造成污染的研究进展,提出了采用矿化垃圾治理和修复垃圾堆场的污染土壤,在实现矿化垃圾的资源化的同时实现污染土壤的无害化．具有很好的应用前景。     

Treatment of Landfill Leachate by a Combined Anaerobic Fluidized Bed and Zeolite Column System

The use of a combined anaerobic fluidized bed and zeolite fixed bed system in sanitary landfill leachate treatment was investigated. Anaerobic treatability studies were successfully performed in the anaerobic fluidized bed reactor. The chemical oxygen demand (COD) removal was attained up to 90% with increasing organic loading rates as high as 18?g?COD/L?day after 80?days of operation. Good biogas production yield (Ygas) of 0.53?L biogas per gram removed COD with methane (CH4) content of 75% was obtained. The attached biomass concentration increased along the column height from bottom to top, and its mean value was found 6,065?mg/L after 100?days of operation. The anaerobically treated landfill leachate was further treated by a zeolite fixed bed reactor. While excellent ammonia removal (>90%) was obtained with the untreated zeolite, the regenerated zeolites showed higher performance. Consequently, this combined anaerobic and adsorption system is an effective tool to remove high COD and high ammonia in landfill leachate.     

萃取－旋流电积工艺从镓锗浸出液中生产阴极铜

介绍了某冶炼厂采用萃取－旋流电积工艺从镓锗浸出液中生产阴极铜的工业化应用情况。在铜的萃取生产过程中,通过优化反萃液酸度、萃取温度,同时监控浸出液中有害杂质含量和增设活性白土有机相净化装置,有效解决了铜萃取率低、分相慢和萃取有机相降解等技术问题;在铜的旋流电积生产中,采用钛基二氧化铅阳极替代钛基贵金属阳极、溶气泵加气浮澄清除油装置替换二级纤维改性材料除油装置,通过铜离子浓度电积终点准确控制、古尔胶助剂添加量、铜电积循环液温度优化,解决了阴极铜析出质量差、钛基贵金属阳极损耗大等生产难题,阴极铜的质量和阳极寿命均得到明显改善。