添加生物炭的水芹湿地对农村低污染水的净化研究

为研究生物炭对湿地处理污水的效果,以种植水芹的湿地系统为对象,通过盆栽试验研究了添加1%和5%煅烧温度为500℃和700℃的两种生物炭对低污染水的净化作用及其对水芹生长的影响。结果表明:加入1%煅烧温度为700℃和500℃生物炭的水芹盆中,系统表面水TN浓度均值在4.05~4.18 mg·L~(-1),低于不加生物炭对照组。煅烧温度为500℃,添加量为1%的生物炭处理组的氨挥发损失总量为96.07 kg·hm~(-2),显著提高;而煅烧温度为700℃,添加量为1%的处理组的氨挥发损失总量(43.02 kg·hm~(-2))与对照相当,其植株地上部分生物量和养分累积量较大,且该种生物炭对土壤养分有一定的固持作用,具有较好的正面效应。通过生物炭和水芹湿地系统的耦合,筛选出了较优的生物炭类型,其在净化污水的同时降低了对环境的负面影响,有效利用了污水中的氮、磷等养分资源,从而为设计农村低污染水的生态修复工程提供了基础数据和技术支撑。     

纳米磺化石墨烯用于异位洗脱污染土壤多环芳烃工艺的优化

Ex-situ soil washing technology offers advantages such as speed and efficiency of remediation and range of application and has been developed to conform with legal requirements and best management practices in USA and some European countries. In this study,nano-sulfonated graphene(SGE) was used as a washing agent to evaluate different processing(washing) parameters for the ectopic leaching removal of polycyclic aromatic hydrocarbons(PAHs) from a coking plant soil. X-ray photoelectron spectroscopy(XPS) and fourier transform infrared spectroscopy(FTIR) were used to analyze the characteristics of the SGE tested. The results showed that SGE had a strong adsorption capacity for PAHs through the role of π-π, H-π, and anion-π interactions. The washing parameters, an SGE concentration of 2 000 mg L~(-1), a liquid/soil(L/S) ratio of 10:1, and 4 cycles of successive washing, were set to arrive to the optimum condition for achieving more than 80% of PAH removal. Under the optimum condition, the PAH removal rate decreased with increasing ring numbers. After one washing cycle at SGE concentration of 2 000 mg L~(-1) and L/S ratio of 10:1, the PAH removal rate of the SGE tested was much higher than that of Tween 80(TW80) or methyl-β-cyclodextrin(MCD)(P 0.01). Therefore, SGE is a promising material for the nanoremediation of PAH-contaminated soils.     

新农药哌虫啶在三种典型土壤中的吸附与淋溶研究

应用振荡平衡法和柱淋洗法研究了哌虫啶在红壤、棕壤和黑土3种典型土壤中的吸附和淋溶特性,并探讨了3种土壤改良剂对其淋溶的影响。结果表明:哌虫啶在黑土、红壤和棕壤中的吸附平衡时间分别为12、12和9 h,分配系数Kd分别为23.16、11.24和4.68,吸附常数Kf分别为22.03、11.69和5.05,KOC值分别为1 619、2 094和495,吸附自由能值分别为-16.96、-17.59和-14.02 k J mol-1,Freundlich和线性等温吸附模型均能较好地描述哌虫啶在土壤中的吸附过程,其吸附能力顺序分别为黑龙江黑土福建红壤山东棕壤。哌虫啶在3种供试土壤中淋溶性存在差异,在棕壤中迁移性最强,随着施药量的增加,其淋出率也略有提高,但3个不同水平施药量差异不显著。在黑土中迁移性最弱,红壤和黑土中的哌虫啶残留量随着土壤深度的增加逐渐降低。土壤中添加0.5%的活性炭、腐殖酸和草炭能显著地降低农药哌虫啶在土壤中的淋溶性,减少对地下水的污染风险。     

Role of effective microorganisms in efficacy of Nemarioc-AG phytonematicide on suppression of Meloidogyne incognita and growth of tomato plants

The release of active ingredient chemicals in conventional organic amendments is primarily through microbial degradation, whereas in granular phytonematicides, leaching through irrigation water had been implied as a probable mechanism. The objective of this study was to determine the role of effective microorganisms (EM) on the efficacy of Nemarioc-AG (NAG; G?=?granular formulation) phytonematicide on suppression of root-knot (Meloidogyne species) nematodes and growth of tomato (Solanum lycopersicum) plants. A 5?×?6 factorial experiment, with EM at 0%, 0.14%, 0.17%, 0.20% and 0.25% and phytonematicide at 0, 3, 6, 9, 12 and 15?g per plant, was conducted under microplot conditions. Each plant was inoculated with 11,000 eggs and second-stage juveniles (J2) of Meloidogyne incognita. Seventy days after initiating the treatments, the interactions were not significant (P?≥?.05) on all variables, but the main factors were highly significant. Regression of nematode population densities, root gall and dry shoot mass over increasing phytonematicide concentration exhibited quadratic relations, which were explained by 93%, 97% and 99%, respectively. In contrast, stem diameter and phytonematicide concentration had a positive linear relation, which was explained by 98%. Nematode numbers over increasing EM concentration exhibited quadratic relation, which was explained by 97%. All plant variables and EM had no significant relations. In conclusion, the efficacy of NAG phytonematicide on nematode suppression and plant growth was independent of EM activities, suggesting that irrigation water played a major role in the efficacy of the product in granular formulation.     

不同形态磷在砂土中的移动性研究(英文)

预测土壤中磷的长期淋洗性需要了解土壤特性和不同形态磷的行为.本研究用模拟试验评估了不同磷负荷砂质土壤中不同形态磷的移动性.分别从浙江省衢州市和温州市采集具不同磷含量的蔬菜地土壤,每一地点分别采集2个深度的土壤(0～10 cm和10～30 cm),表层土壤(0～10 cm)通过添加不同量的磷酸盐、CaCO和无定形氧化铁,形成研究需要的不同磷含量和不同磷形态的系列土壤样品;淋洗柱长30 cm,由10 cm经培养处理的表层(0～10 cm)土壤和未经培养处理的亚表层土壤(10～30cm)构成,每一淋洗土柱连续经历12个循环的0.002 mol?L-1CaCl2溶液淋洗,收集的淋洗液用于分析钼酸反应总磷(TRP)、可溶态钼酸反应磷(DRP)和颗粒态钼酸反应磷(RPP);试验结束后鉴定土壤中水溶态磷、MehlichⅢ-P和磷的化学形态变化.结果表明:添加无定形氧化铁和碳酸钙可显著改变砂土中磷的形态,降低土壤磷的有效性;无定形态氧化铁在降低土壤磷有效性方面的作用大于碳酸钙;淋洗液中磷的形态主要为DRP,颗粒态磷占总磷的比例为1.2%～39.8%;TRP和DRP的损失与培养处理后表土中磷含量存在显著的相关.相关分析和淋洗试验后土壤中磷形态变化结果都表明:表土柱中淋移的磷主要来源于水溶性磷(H2O-P)和NaHCO3-P,与NaOH-P、HCl-P和残余磷的相关不明显;从表土淋失的磷有27.1%～54.2%被淋出土体,其余下移至10～30 cm土层中.研究结果还表明,添加无定形氧化铁可增加土柱中颗粒态磷的迁移.     

浙北平原不同种植年限蔬菜地土壤氮磷的积累及环境风险评价

长期过量施肥可导致蔬菜地土壤养分大量累积、养分利用效率下降和环境污染风险增加。以浙北平原不同种植年限蔬菜地土壤为研究对象,采用化学测试方法研究了菜地土壤氮和磷的积累及其淋失潜力的变化。结果表明,随着种植年限的增加,蔬菜地土壤全磷、有效磷(Olsen P)和NO3-N呈明显的积累;蔬菜种植年限为2、2～5、6～10、11～20、20～30和30a的表土全P平均分别为0.66、0.75、1.07、1.49、2.40和2.12g·kg-1,有效P平均分别为13.2、37.8、42.2、70.2、137.9和101.7mg·kg-1,NO3-N平均分别为9.15、13.58、50.18、46.48、73.28和74.20mg·kg-1,同时土壤N和P垂直下移渐趋明显。土壤水溶性磷含量随土壤有效磷(OlsenP)积累的变化存在一个明显的突变点,相对应的土壤OlsenP临界值约为60mg·kg-1。随着种植年限增长,蔬菜地地表径流中氮和磷浓度呈明显增加,利用年限为20～30a的蔬菜地径流中可溶性P和NO3-N浓度分别约为利用年限2a蔬菜地的13.12和9.48倍。研究认为,长期超量施肥已导致这一地区蔬菜地土壤养分的过度积累,在蔬菜生产中应重视和提倡平衡施肥,控制土壤氮磷的积累。     

Influence of different forage grasses on nitrate capture and leaching loss from a pumice soil

Nitrogen (N) uptake and loss in leachate from a pulse of ¹⁵N-labelled synthetic cow urine applied to a pumice soil were compared in a glasshouse lysimeter experiment among the grass species, Agrostis capillaris , Dactylis glomerata , Phalaris aquatica , Lolium multiflorum , L . perenne and a L . multiflorum/A. capillaris mixture. In addition, four L. perenne treatments investigated the effect of infection by Neotyphodium lolii strains. Leachate volumes and leachate nitrate concentrations were measured. At final harvest 24 weeks after sowing, dry matter (DM) mass of shoots and roots, plant N and ¹⁵N contents, soil residual mineral N, and root diameters and lengths were measured. Endophyte had no effect on plant or nitrate variables. Lysimeters planted with L . perenne (pooled endophyte treatments) leached 48 mg of NO₃-N compared with <3 mg N for the other grasses. Recovery of ¹⁵N was highest in A. capillaris (0·99), followed by D. glomerata and P. aquatica (0·89), the L . multiflorum / A. capillaris mixture (0·87), L . multiflorum (0·60) and L . perenne (0·44). Low ¹⁵N recoveries and high leaching losses from L . perenne were associated with low plant and root masses of DM and low rooting depth. High aerial mass of DM, root systems extending below 20 cm and high root masses of DM in lysimeters with A. capillaris , P. aquatica and D. glomerata contributed to a high rate of nitrate interception by these species and low leachate losses. The L . multifloru m/ A. capillaris mixture was intermediate between the two species for most of the variables measured.     

污水灌溉条件下Cu在农田土壤中的运移及其模拟研究

通过土柱模拟试验,分析污水灌溉条件下Cu在我国7种典型农田土壤中的迁移趋势及其对浅层地下水的污染风险.试验用添加含有Cu(20 mg·L-1)的人工污水以相当于水作4年、旱作10年的灌溉量(20 L)进行土柱淋溶实验,并应用Hydrus-1D软件对Cu在土壤中的运移进行模拟分析.结果表明:黑土、黄潮土和黄绵土对Cu的吸附性能很强,淋出液中Cu浓度低于地下水水质Ⅱ类标准,污水灌溉风险较低,进入土壤中的Cu主要积累在0～5 cm表层,确定性平衡模型(DEM)可以对Cu在黑土、黄潮土和黄绵土土壤剖面中的分布进行拟合;红壤、灰潮土和2种水稻土对Cu的吸附能力相对较弱,进入土壤的Cu含量超过了土壤对它的吸持固定能力,Cu在较短时间里即可穿透土体,对地下水及环境造成潜在危害,污水灌溉风险较大,化学非平衡两点模型(TSM)对Cu在红壤、灰潮土和2种水稻土中的运移有较好的拟舍效果.从Cu在不同农田土壤中的迁移分布及拟合过程来看,土壤对Cu的吸附性能是决定Cu在土壤中迁移的最重要因素,它从宏观上决定了Cu在土壤中迁移、积累的全过程,也是导致污水灌溉条件下Cu在7种农田土壤中迁移差异性的根本原因.     

微生物湿法冶金技术的研究与发展

21世纪人类对微生物技术的开发利用将进入一个迅猛发展的时代,微生物湿法冶金技术可广泛用于矿物加工、冶金、环保等领域。与传统工艺相比,微生物冶金技术有成本低、能耗低、流程简单、环境友好等特点,在低品位难选冶的矿产资源的开发中有着广阔的应用前景。本文对微生物冶金技术进行了较全面的综述,包括微生物湿法冶金的基本原理、浸矿微生物种类、影响浸矿效果的主要因素以及浸矿工艺,介绍了微生物除磷的发展近况,并且展望了微生物冶金技术的发展前景。     

玻璃基质缓释肥料的养分淋溶特性研究

以自制的玻璃基质缓释肥料为供试材料,采用土壤淋溶方法,研究玻璃缓释肥料在土壤中的养分释放规律。结果表明:培养28d后玻璃肥料的氮、钾累积释放率分别为普通肥料的81.34%和75.32%(P<0.01),极大的减少了养分淋溶损失。玻璃肥料在淋溶的中后期仍有一定的氮、钾释放速率和释放量,减少了养分损失率,有效地延长了氮、钾养分供应期,具有明显的缓释效果。