Ryegrass Utilization of Nutrients Released from Composted Biosolids and Cow Manure

Use of composts as soil amendments to enhance crop growth requires a knowledge of rates and amounts of nutrients released. A greenhouse study was conducted using ryegrass (Lolium perenne L.) as a test plant to evaluate this release from composts. The experimental design consisted of four blocked replicates in a complete factorial with two types of compost (wastewater treatment plant biosolids and cow manure), four application rates (1, 2, 5 and 10 percent of weight of sand), and three fertilizer treatments (0, 100 mg N/kg mixture, and 100 mg P/kg mixture). Rye-grass top growth was harvested after 21 days. The regrowth was harvested three additional times. Roots were recovered after the fourth harvest. Total N uptake was significantly and positively affected by the total amount of N supplied by the compost or compost plus N fertilizer (r² values ranged from 0.992 to 0.999). Initial N uptake depended on the mineral N concentration in the compost and was higher from biosolids than from cow manure compost. Biosolids compost contained 10 times more mineral N and this N was primarily taken up in the first two harvests. Cow manure compost, however, provided N gradually over the entire 84 day test. In addition to N, both composts also supplied P, K, and other major and minor nutrients essential for plant growth.     

Multifaceted Approach for Characterization of Solid Residues from Sludge Incineration

The Italian Water Research Institute (IRSA) carried out sludge incineration tests on a demonstrative plant equipped with a circulating fluidized bed furnace. Aim of this paper is to present the potential applicability of non-conventional techniques for solid residues characterization. Results of five tests performed under different operating conditions are discussed. Incineration solid residues were sampled from the cyclone, downstream the furnace (cyclone ash, CA), and from the bag filter (filter ash, FA). Different techniques were used by the Mechanical and Industrial Engineering Department of the Roma TRE University, which cooperated with IRSA in the research project, to characterize incineration products and to correlate with process parameters. The X-ray Diffraction (XRD) technique was used to estimate the amount of sand, lost from the furnace, in CA and FA samples. Particle size distribution was measured using Low Angle Laser Light Scattering (LALLS). Scanning Electron Microscopy associated with Energy Dispersive Spectroscopy (SEM/EDS) was used to correlate size and shape of individual particles with chemical composition.This multifaceted approach to characterize incineration residues appears promising, providing additional and complementary information to the traditional chemical characterization.     

Use of Raw and Composted Paper Sludge as a Soil Additive or Mulch for Cottonwood Plants

Pulp and paper sludge is a by-product of paper production and may be suitable in agricultural applications as a soil amendment or mulch. The objective of this study was to evaluate raw and composted pulp and paper sludge as soil additives or mulches for cottonwood plants. Primary sludge, a combination of by-products from bleached kraft and neutral sulfite semichemical paper, was mixed with tailings, slaughterhouse paunch, and 10 percent wood ash (by volume), and used raw or composted and cured in the field for 39 weeks. Cuttings of two cottonwood (Populus deltoides Bartr. ex Marsh) clones were planted in a field soil (Quincy loamy fine sand) that was mixed (incorporated) or mulched (placed on top the soil) with raw or composted sludge mixtures at application rates of 0,45,90, 135 and 180 Mg/ha. The plants were grown in a plastic house for nine weeks. Electrical conductivity (EC), cation exchange capacity (CEC), soluble Cl and extractable Na in soil amended with 180 Mg/ha of compost were 37, 22, 197 and 138 percent higher, respectively, than those of soil amended with the raw sludge mixture at the same rate. Bulk density of amended soil decreased, whereas soil aeration and water-holding capacity increased as sludge application rate increased. After nine weeks, raw or composted sludge applied at a rate of 135 Mg/ha, whether used as a mulch or incorporated, improved cottonwood plant height by 40 percent and stem diameter by 20 percent compared to plants grown in nonamended, nonmulched (control) soil. These results indicate that the pulp and paper sludge mixtures, whether raw or composted, improved soil characteristics and aided establishment of cottonwood cuttings.     

pH Requirement for the Bioleaching of Heavy Metals from Anaerobically Digested Wastewater Sludge

Bioleaching has been demonstrated to be a feasible technology for removing heavy metals from sewage sludge, but the leaching medium needs to be pre-acidified to less than 4. The objective of the research presented in this paper was to investigate the pH requirement for isolated indigenous Thiobacillus ferrooxidans for bioleaching heavy metals from wastewater sludge in Hong Kong. Isolated sludge-indigenous iron-oxidizing bacteria were used for the bioleaching experiments to investigate the dissolution behaviour of heavy metals (Zn, Cu, Ni and Cr) from sludge set at an initial pH ranging from 3–7 with the purpose to reduce the acid consumption. The results showed that the inoculation of 15% of isolated indigenous iron-oxidizing bacteria and addition of 4.0 g L^-1 Fe²⁺ (in the form of FeSO⁴?7H₂O) resulted in a sharp decrease in sludge pH from an initial pH 3–7 to 2.1–2.4 and an increase in ORP (oxidation-reduction potential) from –200–38 mV to > 500 mV within the first 6 days. After 16 days of bioleaching, 50.2–78.4% of Cr, 63.7–74.1% of Cu, 74.9–88.2% of Zn and 15.5–38.6% of Ni can be leached out from the sludge at an initial pH range of 3–7. In contrast, only 1.5% of Cr, 1.7% of Cu, 15.3% of Zn and 15.5% of Ni was solubilized in the control run at pH 7.0. At the end of bioleaching, the dissolution of nutrients N and P from the organic matrix at pH 6 was significantly less than that at pH 3–5. Hence, the bioleaching efficiency could still be maintained at an initial pH of > 4 using the isolated indigenous T. ferrooxidans which would reduce the cost of operation.

     

Effects of Humic Acids Extracted from Mined Lignite or Composted Vegetable Residues on Plant Growth and Soil Microbial Populations

Growing interest in the market for humic substances with agricultural applications has led to the development of new potential sources of these compounds other than fossil matrices (e.g. different kinds of lignite), which, until now, have represented the main raw material for the extraction of humus-like products. High quality compost (green compost) obtained through the aerobic biostabilization of selected organic residues, such as vegetable waste from source-collection at garden-produce markets, may be considered for this purpose. Beyond the primary need to develop technically and economically reliable procedures for the extraction of humic substances from compost at the industrial scale, importance must be placed on controlling the influence of such compounds on soil-plant systems. Humates from leonardite, representative of the active agents among humus-based commercial preparations, have been compared in pot trials with humic acids, potassium salts, from green compost in order to evaluate their respective effects on soil microbial activity and plant productivity. Differences between pot blocks amended with humic acids have suggested that humus-like substances extracted from compost seem to exert higher stimulative effects on microbial growth and vegetative biomass production than fossil humates.     

Hydrochars from Biosolids and Urban Wastes as Substitute Materials for Peat

Peat is the most widely used substrate component and extensively used in greenhouse cultivation, landfill cover soils, urban parks and gardens, urban agriculture or green roofs, due to its excellent combination of physicochemical properties. The production of hydrochar by hydrothermal carbonization (a process at lower temperatures than pyrolysis and using wet conditions) could industrially reproduce the initial conditions of biomass humification and lead to materials with similar properties to those of peat. The objective of this work was to compare peat (PT, Control), a hydrochar prepared from biosolids (HSL), a hydrochar prepared from the organic fraction of urban wastes (HUW) and two mixtures (PT + HSL and PT + HUW) at a 50% volume rate for their potential use as substrates with multiple applications. Ryegrass was established at a rate of 40 g seeds cm⁻² in the potting mixtures. Hydrophysical and biochemical properties (microbial biomass and the enzymes dehydrogenase, β‐glucosidase and phosphomonoesterase) were analyzed for PT, HSL, HUV and their combination (PT + HSL and PT + HUW). Treatments with biosolids hydrochar increased ryegrass production by 184% (HSL) and by 216% (PT + HSL) dry weight compared to the control (peat). Biochemical properties depended strongly on hydrochar type, while the hydrophysical properties of the hydrochars were similar to those of peat. Overall, our results found hydrochar–peat mixtures (PT + HSL and PT + HUW) to be suitable for the preparation of growing media. Copyright © 2017 John Wiley & Sons, Ltd.     

城市污泥堆肥与氮肥配施对稻田CH4和N2O排放及水稻重金属含量的影响

随着城市污泥量的日益增大,污泥农用备受关注。本研究通过田间原位试验,以水稻为研究对象,观测氮肥与污泥堆肥以不同比例(1︰0、0.75︰0.25、0.5︰0.5、0︰1)配合施用对稻田CH₄和N₂O排放以及植物重金属累积的影响。结果表明:随着污泥堆肥施用比例的增加,稻田CH₄排放呈线性增加(P<0.05,r=0.967)。与施全量氮肥处理相比,施全量污泥堆肥处理显著增加CH₄排放118%(P<0.05),而配施处理的CH₄排放仅增加30%～34%(P>0.05)。与CH₄相反,稻田N₂O排放随着污泥堆肥施用比例的增加而逐渐减少,与施全量氮肥处理相比,施全量污泥堆肥处理减少N₂O排放39%(P<0.05),配施处理N₂O排放减少29%～38%(P<0.05)。施全量污泥堆肥处理的温室气体排放强度(GHGI)与施全量氮肥处理相当,而配施处理的GHGI比施用全量污泥堆肥...     

Anaerobic Fluidized Bed Degradation and the Development of a Kinetic Model for a Particulate Organic Matter Enriched Wastewater Sludge

The starch manufacturing industrial units, such as sago mills,both in medium and large scale, suffer from inadequate treatment and disposal problems due to high concentration of suspended solids present in the sludge. A laboratory scale study was conducted to investigate the viability of anaerobic treatment of sago waste sludge, enriched in particulate organicmatter, using a fluidized bed reactor. The start-up of the reactor was carried out using a mixture of digested supernatantsewage sludge and cow dung slurry in different proportions. The effect of operating variables such as COD of the effluent, bed expansion, minimum fluidization velocity on efficiency oftreatment and recovery of biogas was investigated. The maximum efficiency of treatment was found to be 82% and the nitrogen enriched digested sludge was recommended for agricultural use. A kinetic model was developed for the degradation of particulate organic matter using the general kinetic equation [dS/dt = K _HC SX_C] which allowed for a more accurate mathematical representation of the hydrolysis process. Analysing data from a series of batch tests, the best fit value of C was found to be in the range 0.43 to 0.62.     

Removal of Ammonium and 4-Methylphenol from Synthetic Wastewater by Cell-Free Extracts of Nitrifying Sludge

Fluoroquinolone antibacterial agents (FQs) are the most commonly detected antibiotics in soil/groundwater which cause chronic effects on human beings as well as aquatic ecosystems. The current situation of the regulation, occurrence, fate, and sources of FQs in soil/groundwater was systematically analyzed in this paper. And then, the important factors affecting milligram per liter concentration of FQs sorption in soil, such as pH, cation exchange, clay minerals, organic content, surface complexation, and microbial degradation or transformation, were summarized. Actually, nanogram-microgram per liter concentration is detected frequently in soil/groundwater by far. Due to the extensive application of FQs and its relatively stable physicochemical characteristics, the higher concentration in soil/groundwater would appear in the coming decades which may exert a threat to freshwater and human beings. To the knowledge of the authors, no full-scale fate, occurrence, spatial, and temporal variations of FQs in soil/groundwater have been reported in the scientific literature. Therefore, it is recommended that more comprehensive studies are required to fill knowledge gaps in low-concentration transport, fate and occurrence, spatial, and temporal variations of FQs in soil/groundwater and their potential risk assessment to human and ecosystem.

     

Comparison of Cassava Distillery Residues and Straw as Bulking Agents for Full-scale Sewage Sludge Composting

To solve problems of bulking agents shortage for sewage sludge (SS) composting and of disposal of cassava distillery residues (CDR) in the alcohol industry, the effects of using CDR instead of maize straw as bulking agents were investigated at full scale in Rizhao, China. This was done by comparing CDR-added and straw-added piles. Both CDR and straw promoted sanitation achievement of SS composts. CDR was effective at increasing fermentation temperature, whereas straw was superior in maintaining the thermophilic phase. The free air space (FAS) of matrices provided by CDR or straw were sufficient (>30%) for fermentation, and showed rising trends during composting. Extensive mass reduction was also accomplished in composting even after considering the weight of added straw or CDR. Compared with straw-added piles, CDR-added piles showed less average FAS (51.42%), water removal (49.68%), and organic matter (OM) loss (21.51%), but greater volume reduction (16.34%). The time-dependence of OM loss varied between the CDR-added (which followed zero-order kinetics) and straw-added (first-order kinetics) piles. After fermentation, the composts were phytotoxin-free in both treatments. The CDR-added piles had lower EC (2,221 μS cm^?1) and C/N (13.29) than straw-added piles. A smaller germination index (73.59%) for CDR-added piles, combined with higher pH (7.33) and oxygen consumption rate (4.33 mL L^?1 min^?1), suggests that SS composting with CDR requires a longer time to reach maturity than with straw. However, CDR can be used instead of maize straw as a bulking agent for full-scale SS composting.     

Chemically Modified Crop Residues as a Low-Cost Technique for the Removal of Heavy Metal Ions from Wastewater

Batch adsorption experiments were carried out to evaluate the effect of type of crop residues and chemical pretreatment solutions on the removal efficiency of heavy metal ions at different concentrations of synthetic wastewater solutions. Rice straw, cotton stalks, and maize stalks were pretreated with different solutions (i.e., sulfuric acid, oxalic acid, sodium hydroxide, and distilled water as the control treatment) in order to increase their metal-binding capacity. Results indicated that cotton stalks were the best biosorbent material according to their efficiency in removal of heavy metal ions. Sodium hydroxide was the best chemical pretreatment method for stimulating the biosorption capacity of crop residues. Ions of Pb²⁺ had the highest biosorption ratio among all competitive ions, whereas Mn²⁺ ions had the lowest. The removal efficiency decreased as the concentration of heavy metal ions increased in aqueous solutions. Sorption equilibrium isotherms could be described by the Langmuir model in most cases, whereas an isotherm of S shape was observed in other cases, which did not follow the Langmuir isotherm model. In conclusion, cotton stalks pretreated with sodium hydroxide could be used as an efficient technique for wastewater remediation prior to irrigation due to its low-cost, little processing, and high biosorption capacity.     

甘蔗基因组DNA简单和快速提取方法

目前国内外关于提取DNA的方法很多(Honeycutt et al．，1992；顾红雅和瞿礼嘉，1998)，但因研究的对象和目的不同而有所差异。甘蔗含有大量的酚和多糖等有机物质，由于这些物质的干扰，按照常规提取植物组织总DNA的方法提取甘蔗基因组DNA，常常因产量小和纯度低而不能满足实验要求。本实验在前人研究的基础上(Honeycutt et al．，1992；顾红雅和瞿礼嘉，1998)，对所用药品及技术进行改进，摸索出一套快速、简便且可获得高质量基因组DNA的改良方法。用此方法提取的DNA进行酶切、RAPD和Southem杂交分析，都取得了良好的效果。     

水电、水库、矿产开发中提取-定资金用于水土保持治理的研究

水电、水库、矿产开发对于生态与环境造成的问题已成为水土保持工作的难题和热点.在广泛收集和分析国内水电、水库、矿产开发中水土保持状况的基础上,对于开发项目执行较好的浙江、陕西、山西、内蒙等地的一些企业进行了专题调研.结合项目实际对于个别典型企业进行了调查,分析了存在的问题.调研结果认为,从水电、水库、矿产开发收益中提取资金用于水土保持具有可行性和必要性.提出了将提取资金政策提升为法律条文,提取合理比例的资金,且将这部分资金列入税前列支等建议.     

兰州市城市污水处理厂污泥中重金属形态分布特征与潜在生态风险评价

通过现场调查采样及室内分析,研究了兰州市七里河安宁污水处理厂和雁儿湾污水处理厂污泥中重金属的形态分布特征,并对其进行了潜在生态风险评价。结果表明,污泥总体呈高有机质、高全N和有效P、高微量营养元素,且Cu、Zn、Cd、Pb、Ni5种重金属的含量均低于污泥农用控制标准,具有很好的农用价值。污泥中Zn、Cd、Pb主要以有机结合态和残渣态存在,而Cu、Ni可交换态所占比例较高,分别为14.95%和14.41%,不稳定态所占比例分别为41.12%和31.04%,表现出较高的生物活性和可利用性。七里河和雁儿湾污泥中重金属的潜在生态风险属于低度风险;Cd、Cu是污泥中重金属潜在生态风险的主要贡献者,在污泥处理处置时应引起高度重视。     

Long-Term Effects of Tourmaline on Nitrogen Removal from Wastewater and Bacterial Community Shift in Activated Sludge at Low Temperatures

In this study, the long-term effects of ultrafine tourmaline particles (UTPs) on the removal of nitrogen in wastewater, activated sludge viability and microbial population dynamics at low temperatures were investigated. Although there was no significant effect on the effluent concentrations of nitrogen after long-term exposure to 1 g/L UTPs at low temperatures, the oxidation rate of NH₄⁺-N and the accumulation rate of NO₂^?-N increased and the formation rate of NO₃^?-N decreased during the aerobic phase of sequencing batch reactors. However, long-term exposure to 1 g/L UTPs did not significantly affect the microbial community richness and the community diversity of activated sludge at low temperatures. The mechanism of tourmaline was studied by assessing the dominant functional species involved in biological nitrogen removal from wastewater. It was found that 1 g/L UTPs increased the removal rate of nitrogen by reducing the relative abundance of nitrite oxidizing bacteria and increasing the relative abundance of ammonia oxidizing bacteria after long-term operation at low temperatures.     

添加造纸白泥对猪场废水厌氧消化液中氮磷回收的影响

以造纸废弃物白泥作为pH调节剂,利用MAP沉淀法回收厌氧消化液中的氮磷,并采用曝气的方式提高消化液pH值和造纸白泥的溶解性,研究了造纸白泥的添加量和曝气时间对厌氧消化液中氮、磷回收效果的影响,并考察了曝气过程中pH、COD、PO34--P、NH3-N、Mg2＋、Ca2＋的变化规律。结果表明造纸白泥的添加量为8g.L-1,曝气时间为120min时,PO34--P和NH3-N的回收率分别达到98和59,出水的PO34--P和NH3-N浓度分别为0.98mg.L-1和60.66mg.L-1,均达到了《畜禽养殖业污染物排放标准》（GB18596—2001）的要求,同时,COD的去除率为45;如果仅用曝气方式处理,120min后PO34--P和NH3-N的回收率仅分别为66和41,均未达到排放标准要求。可见,与仅用曝气方式处理相比,添加造纸白泥协同曝气对厌氧消化液中氮磷的回收有明显的效果。     

二氟沙星残留检测直接竞争ELISA试剂盒的研制及其性能测定

应用抗二氟沙星单克隆抗体（DIFmAb）杂交瘤细胞株建立直接竞争ELISA分析方法,研制出DIF残留快速检测试剂盒（DIF-Kit）并对其性能进行了测定。特异性试验结果表明与达氟沙星的交叉反应率为0.32％,与其它氟喹诺酮类药物和磺胺类药物无交叉反应,该方法对DIF的检测限可达到0.1µg/L,半数抑制浓度IC50为2.2µg/L,线性范围0.1～128µg/L, 平均批内和批间变异系数小于<15%。对牛奶、鸡肉分别添加0.4、2.0、10.0、50.0µg/LDIF标准品,平均回收率分别为89.3%和83.9%。DIF-Kit性能稳定,在4℃可保存6个月。DIF-Kit准确度高、重复性好、特异性强,适用于DIF残留快速检测的推广应用。     

降解多菌灵和啶虫脒残留的复合菌剂研发及初步应用

针对菜田土壤中多菌灵和啶虫脒的残留问题，以多菌灵降解菌株Rhodococcusqingshengiidjl-6和啶虫脒降解菌株Pigmentiphaga D-2作为材料，进行降解菌剂的复配，研究了使用复合降解菌剂对复合农药残留土壤的修复效果及微生态效应。研究结果表明：(1)复配降解菌株djl-6与D-2的最适体积比为5∶3，复合降解菌剂在3 d内对无机盐培养基中50μg/ml的多菌灵降解率为87.14%，对50μg/ml的啶虫脒降解率为96.10%。(2)初始接种量为7%时，复合降解菌剂可在6 d内将复合农药污染土壤中5 mg/kg多菌灵降解74.40%，将5 mg/kg啶虫脒降解95.87%。土壤含水率为25%时，复合降解菌剂对复合农药污染土壤中5 mg/kg多菌灵的降解率为80.80%，对5 mg/kg啶虫脒的降解率为97.87%。(3)复合农药污染土壤中10 mg/kg多菌灵和10 mg/kg啶虫脒即可对小青菜的生长产生明显的药害，小青菜生长24d时根长仅为空白对照的66.56%、茎叶长为58.35%、鲜重为45.13%。在7%的接种量条件下，复合降解菌剂可解除药害，使小青菜的生...     

Microfauna Community as an Indicator of Effluent Quality and Operational Parameters in an Activated Sludge System for Treating Piggery Wastewater

In order to study the potential use of microfauna as an indicator of effluent quality and operational parameters in an activated sludge system for treating piggery wastewater, an experimental sequencing batch reactor was set up and evaluated by biological and physical–chemical analyses for 12 months. Results show that microfauna (and specifically ciliate protozoa) are a good parameter for assessing effluent quality in terms of both chemical oxygen demand (COD) and ammonia and for assessing the organic and nitrogen load of the system. Specifically, the abundance of ciliates decreases from 20,000 individuals·mL^?1 to ca. 2,500 individuals·mL^?1 and from ca. 10,000 individuals mL^?1 to ca. 200 individuals mL^?1 when effluent concentration is between 550 and 750 mg L^?1 and above 100 mg L^?1 to the COD and ammonia concentrations, respectively. Furthermore, microfauna abundance is reduced from ca. 18,000 individuals mL^?1 (organic load between 0.1 and 0.2 mg COD mg total suspended solids (TSS)^?1 day^?1) to ca. 500 individuals mL^?1 (organic load between 0.3 and 04 mg COD mg TSS^?1 day^?1). Microfauna abundance also decreases as nitrogen loading increases. Nitrogen loading in the range of 5–60 mg NH₄–N g TSS^?1 day^?1 does not have any significant effect on microfauna abundance. However, ammonia loading from 60 to 120 mg NH₄–N g TSS^?1 day^?1 reduces microfauna abundance ca. 6-fold. Ciliate protozoa were the largest microfauna group during the whole period of study, representing ca. 75% of the total microfauna abundance. The largest group in the ciliate community was that of the free-swimming ciliates. This was followed by the group of attached and crawling ciliates. Specifically, the dominant ciliate species during the whole study period were Uronema nigricans, Vorticella microstoma-complex, Epistylis coronata, and Acineria uncinata.     

脂肪组织RNA提取的三种方法比较与改进

脂肪组织单位体积细胞数少,且单位细胞富含脂类RNA含量相对较少（Mersmann,2002）,这增加了从脂肪组织提取RNA的难度.本研究以脂肪组织为材料,比较了几种商品化的总RNA提取试剂盒,优化和改进某些提取步骤,从而得到了符合实验要求的总RNA.