Co-incorporation of biodegradable wastes with crop residues to reduce nitrate pollution of groundwater and decrease waste disposal to landfill

Return of high nitrogen (N) content crop residues to soil, particularly in autumn, can result in environmental pollution resulting from gaseous and leaching losses of N. The EU Landfill Directive will require significant reductions in the amounts of biodegradable materials going to landfill. A field experiment was set up to examine the potential of using biodegradable waste materials to manipulate losses of N from high N crop residues in the soil. Leafy residues of sugar beet were co‐incorporated into soil with materials of varying C:N ratios, including molasses, compactor waste, paper waste, green waste compost and cereal straw. The amendment materials were each incorporated to provide approximately 3.7 t C per hectare. The most effective material for reducing nitrous oxide (N₂O) production and leaching loss of NO₃^? was compactor waste, which is the final product from the recycling of cardboard. Adding molasses increased N₂O and NO₃^? leaching losses. Six months following incorporation of residues, the double rate application of compactor waste decreased soil mineral N by 36 kg N per hectare, and the molasses increased soil mineral N by 47 kg N per hectare. Compactor waste reduced spring barley grain yield by 73% in the first of years following incorporation, with smaller losses at the second harvest. At the first harvest, molasses and paper waste increased yields of spring barley by 20 and 10% compared with sugar beet residues alone, and the enhanced yield persisted to the second harvest. The amounts of soil mineral N in the spring and subsequent yields of a first cereal crop were significantly correlated to the lignin and cellulose contents of the amendment materials. Yield was reduced by 0.3–0.4 t/ha for every 100 mg/g increase in cellulose or lignin content. In a second year, cereal yield was still reduced and related to the cellulose content of the amendment materials but with one quarter of the effect. Additional fertilizer applied to this second crop did not relieve this effect. Although amendment materials were promising as tools to reduce N losses, further work is needed to reduce the negative effects on subsequent crops which was not removed by applying 60 kg/ha of fertilizer N.     

污泥生物炭基堆肥对锰污染土壤性质及其修复的影响

城镇化快速发展迫切要求对日益增加的城市污泥进行有效处理,为此尝试将其通过热解工艺制成生物炭,作为有机肥料添加剂来改善有机肥品质,通过考察污泥生物炭对猪粪堆肥的影响,并在锰污染土中施加肥料栽培白菜,重点探究500℃热解污泥生物炭肥料对土壤物理化学和微生物性质以及白菜产量的影响。结果表明,热解能增加污泥生物炭的比表面积和提高p H;生物炭的添加能加快堆肥速度,提高堆肥品质;生物炭肥料在盆栽过程中能有效改善土壤性质(如提高p H和电导率,增加细菌和真菌群落总数,使脱氢酶和脲酶活性增强,提高氨氧化古菌和氨氧化细菌的浓度),增加白菜产量,同时降低重金属锰的有效性,将部分酸溶态锰转化为残渣态。     

污泥施用对4种绿化植物叶片性状和光合作用的影响

通过向种植土内添加不同比例的污泥用量,观测盆栽绿化植物叶片性状和光合生理的变化,筛选不同植物的适宜污泥用量。结果表明,‘金叶’梓树和‘红叶’石楠以25.0%浓度处理下,植物叶片性状和光合生理表现最强,可提高比叶面积、净光合速率和叶绿素含量;‘紫花’海棠也表现为相似的生理响应,改变各项生理指标以适应添加污泥的土壤,以12.5%含量处理效果佳。相反,乌桕的表现较差,随着浓度增加表现越差。建议在用封场土种植绿化植物时最多可添加25.0%的生污泥,绿化植物可选择‘金叶’梓树和‘红叶’石楠。     

A Study of the Vertical Vibration of the 4200 Thick Plate Rolling Mills

In this paper,the mill stand and the rolled piece were studied as a system. Based on the disoreted masses and the deformation of bending curve of the roller and roll housing, according to Rayleigh method,the equivalent mass and and the equivalent stiffness of the mode were solved,and set up a multiple degree of freedom vibration dynamic model. And also did theoretical analysis and calculation with an exapmle of the 4200 thick plate rolling mills.     

Retention behavior of size and aluminum components on handsheets in rosin-ester size/alum systems

Anionic emulsion sizes consisting of rosin triglyceride esters and partly fortified rosin acids (i.e., rosin-ester sizes), have recently been used as internal sizes for alkaline papermaking. In this study, handsheets were prepared from pulp suspensions with alum and a rosin-ester size under various conditions, and sizing degree and size and aluminum contents of the handsheets were determined. Aluminum compounds originating from alum added to the pulp suspensions behave as retention aids of the rosin-ester size even in alkaline papermaking under limited conditions. Carboxyl groups in pulp are the primary retention sites of aluminum compounds in pulp suspensions. They form cationic sites on pulp fibers, and thus the anionic size emulsion particles are adsorbed on pulp fibers by electrostatic interactions. However, the cationic charges of aluminum compounds on pulp fibers decrease and finally disappear completely with the lapse of time after the alum addition by forming ionic bonds between the cationic sites and OH^– ions. Thus, pH values of the pulp suspensions and timing of the size addition strongly influence the retention values of the rosin-ester size and the resultant sizing features.This research was presented in part at the 1995 autumn meetings of the Society of Fiber Science and Technology Japan in Hamamatsu, October 1995     

甘肃补血草属植物资源及综合利用价值

采用野外调查采集、查阅文献资料、编制分类检索表等方法,调查整理甘肃补血草属植物资源及其综合利用情况,发现甘肃补血草属植物共5个分类群(4种1变种),分别为二色补血草、细枝补血草、黄花补血草(变种)、星毛补血草和耳叶补血草;其化学成分丰富、药理作用显著,还具有生态学、绿化观赏和饲用等价值。     

城市污水处理厂污泥处理处置及利用浅析

污泥的处理处置与利用是当今面临的重要问题.文章分析了我国污泥处理的现状,介绍了污泥的组成、性质,讨论了污泥处理处置的各种方法及利用方式,最终得出了污泥的材料化利用是污泥处置的理想途径的结论.     

UASB处理养猪场废水条件下进水浓度对污泥颗粒化的影响

UASB能够在很高负荷下稳定运行的重要原因在于反应器内形成的厌氧颗粒污泥。该文研究了利用UASB处理猪场废水时进水COD浓度对污泥颗粒化的影响，结果发现：颗粒直径随进水浓度的上升而增高，受传质过程中所能进入颗粒内部的营养量所控制，因此要根据COD去除率的情况适时提高进水浓度，及时地随微生物数量的增加补充营养，促进污泥颗粒化；也可以避免因浓度变化太快引起细菌生长过快，污泥结构松散，沉降性能下降，COD去除率和产气率降低。     

DETERMINATION OF OLIVE MILL WASTEWATER TOXIC EFFECTS ON THREE MINT SPECIES GROWN IN HYDROPONIC CULTURE

The effects of two olive mill wastewater (OMW) dilutions upon physiological function and metabolic components of three mint species grown in hydroponic culture were studied. Visible symptoms, chlorosis and stunted growth, were pronounced in peppermint and spearmint; toxicity symptoms in menthe douce were few. Peppermint and spearmint displayed loss of calcium (Ca), magnesium (Mg), and potassium (K); menthe douce revealed accumulation of Ca, sodium (Na), and iron (Fe), under OMW. The loss of Ca negatively affected the development and stability of cell wall and membrane; the Mg deficiency negatively affected the photosynthetic apparatus and carbon fixation. Fv′/ Fm′ was slightly affected under OMW, whereas, Φ_PSII, q _P and Rfd displayed significant reductions. No clear effect of OMW on phenols and carbohydrates among the species were found. Ascorbic acid content in peppermint dropped dramatically; the reduction was lower for spearmint and menthe douce. The OMW resistant species, menthe douce, developed a mechanism to control the physiological and the biochemical status.     

国内外竹材造纸及其经济效益评价

本文根据国内外(包括中国、印度、日本、孟加拉国、缅甸、菲律宾、澳大利亚、苏联等)报道的竹材制浆造纸方面资料综合而成。文章内容有引言、竹材纤维形态与化学成分、世界竹材造纸工业简况和造纸竹材利用的经济效益。文章列举大量事实说明造纸工业用竹材为原料比用针叶材或阔叶材经济效益高。