四川丘区猪肉生产生命周期资源消耗和环境污染研究

采用生命周期方法学和情景分析法相结合的方式,对四川丘区3种典型的养猪生产情景进行了猪肉生产的生命周期资源消耗和环境污染分析。结果表明,设定参数下不同的生产系统具有不同的环境影响方式：情景A（散养模式）具有最大的气候变暖潜势（4.8128kg CO2-eqv·FU-1）,情景B（适度规模养猪）具有土地占用最多（12.13m·2FU-1）、不可更新能源消耗最大（18.2MJ·FU-1）、酸化效应（0.0643665kg SO2-eqv·FU-1）和富营养化（1.81695kg O2-eqv·FU-1）最严重等,而情景C（集约化养猪）水资源消耗（1942.69kg·FU-1）最大。此研究揭示了四川丘区主要养猪模式中的污染物排放和资源消耗差异及其影响因素,为养猪业可持续发展规划提供了一定的参考依据。     

皂角苷增强洗脱复合污染土壤中多环芳烃和重金属的作用及机理

通过增溶实验和土壤洗脱实验,研究了一种生物表面活性剂——皂角苷（saponin）对多环芳烃-重金属复合污染土壤的洗脱作用及机理。结果表明,皂角苷对菲、芘等多环芳烃有极强的增溶作用,当皂角苷浓度为0.04%时,菲、芘在液相中的表观溶解度分别增大了约22倍和128倍,因而皂角苷能显著增强多环芳烃污染土壤中菲、芘的洗脱,洗脱效率最大分别可达84.1%和81.4%,增大了约2倍和17倍。皂角苷可与重金属离子形成水溶性的络合物,从而增强洗脱重金属污染土壤中的Zn^2＋和Cd^2＋,在皂角苷浓度为0.4%时,Zn^2＋、Cd^2＋的洗脱效率分别可达93.0%和79.4%,增大了约75倍和8倍。皂角苷可同时洗脱多环芳烃-重金属复合污染土壤中的菲、芘和Zn^2＋、Cd^2＋,洗脱效率分别达87.6%、83.5%和92.3%、78.6%,重金属的存在略增大了皂角苷对菲、芘等多环芳烃的洗脱效率,但多环芳烃对Zn^2＋、Cd^2＋的洗脱效率没有明显影响。皂角苷可同时增强洗脱复合污染土壤中的多环芳烃和重金属,从而为多环芳烃-重金属复合污染土壤的修复奠定基础。     

单养模式下罗非鱼亲本培育塘的沉积物产污系数初探

采用试验塘养殖方法研究了单养模式下罗非鱼（Oreochromis niloticus）亲本培育塘的沉积物污染物含量及沉积物产污系数。结果表明,单养模式下罗非鱼亲本培育塘的沉积物含水率、总有机质、TN、TP和有效磷的含量以及表层沉积物的氮磷比分别在61.07%～68.87%、5.42%～6.82%、2.12～3.18 mg.g^-1、0.34～0.45 mg.g^-1、15.39～24.92μg.g-1和5.74～7.85之间,上述指标在池塘水平分布上没有表现出变化的规律性。面积法和产量法计算得到的湿泥、干泥、总氮、总磷、有效磷、有机质的产污系数分别变化在5.60～15.13 kg.m-2、1.81～5.08 kg.m-2、7.24～23.86 g.m^-2、1.13～3.08 g.m^-2、0.06～0.18 g.m^-2、161.76～526.85 g.m-2和7.89～30.35 kg.kg^-1、2.55～10.19 kg.kg-1、10.43～47.86 g.kg^-1、1.59～6.18 g.kg^-1、0.08～0.36 g.kg^-1、256.37～1 004.69 g.kg^-1。同时,面积法计算显示,两试验塘的湿泥、干泥、总氮、总磷、有效磷、有机质的产污系数均差异不显著（P〉0.05）;而产量法计算显示,除底泥有效磷的产污系数差异不显著外（P〉0.05）,两试验塘的湿泥、干泥、总氮、总磷、有机质的产污系数均差异显著（P〈0.05）。这表明,当养殖模式、养殖技术、放养密度、投喂饲料等要素基本一致时,用面积法测定的沉积物产污系数比用产量法测定的稳定。     

Quantifying fish species richness and abundance in Amazonian streams: assessment of a multiple gear method suitable for Terra firme stream fish assemblages

A multigear sampling method to quantify fish richness and abundance in Amazonian Terra firme streams was assessed. This method is based on the four‐pass removal method using the combined application of different nets. The efficiency of the method was explored over 10 replicated sites along three streams over day, night and seasons. Use of four successive passes allowed both abundant and rare species to be collected and the abundance of common species to be estimated. On average, a high proportion (41%) of rare species was collected per sample (only one or two individuals) after four fishing passes. The efficiency of the sampling method to detect species richness per sample between successive passes was estimated using an autosimilarity approach. Although species richness and abundance increased with successive passes, no major differences were obtained between the third and fourth pass. A single pass considerably underestimated the richness and abundance of species in these type of streams, and night sampling also increased beta‐diversity by at least 20%. Abundance estimates demonstrated high efficiency with an overall sampling error of only 8 and 11% for samples and single species, respectively. Capture efficiency differed among fish species exhibiting different ecological traits and showed significant differences among seasons for total samples. Results supported the robustness of the method and its suitability to quantify fish richness and abundance in small, wadeable Amazonian Terra firme streams inhabited by highly diverse fish assemblages.     

Nitrogen Removal Improvement by Adding Peat in Deep Soil of Subsurface Wastewater Infiltration System

In order to enhance the nitrogen removal, a subsurface wastewater infiltration system (SWIS) was improved by adding peat in deep soil as carbon source for denitrification process. The effects of addition of carbon source in the underpart of the SWIS on nitrogen removal at different influents (with the total nitrogen (TN) concentration 40 and 80 mg L⁻¹, respectively) were investigated by soil column simulating experiments. When the relatively light pollution influent with 40 mg L⁻¹ TN was used, the average concentrations of NO₃⁻-N and TN in effluents were (4.69±0.235), (6.18±0.079) mg L⁻¹, respectively, decreased by 32 and 30.8% than the control; the NO₃⁻-N concentration of all effluents was below the maximum contaminant level of 10 mg L⁻¹; as high as 92.67% of the TN removal efficiency was achieved. When relatively heavy pollution influent with 80 mg L⁻¹ TN was used, the average concentrations of NO₃⁻-N and TN in effluents were (10.2±0.265), (12.5±0.148) mg L⁻¹ respectively, decreased by 20 and 21.2% than the control; the NO₃⁻-N concentration of all effluents met the grade III of the national quality standard for ground water of China (GB/T 14848-1993) with the values less than 20 mg L⁻¹; the TN removal efficiency of 94.1% was achieved. In summary, adding peat in the underpart of the SWIS significantly decreased TN and NO₃⁻-N concentration in effluents and the nitrogen removal efficiency improved significantly.     

土壤总氮和总磷含量的高光谱遥感预测

用遥感技术监测土壤养分是精准施肥中的一个重要手段。为此,在对118个风干的土壤样本的室内反射光谱进行预处理的基础上,分析了土壤总氮和总磷浓度与预处理后的反射光谱的相关性。分别选用与总氮和总磷浓度具有较强相关性的3个波段(分别是684,724,1 890,2 002nm和2 342,1 092,639,2 262nm),用偏最小二乘方法建立了土壤总氮和总磷含量预测的高光谱分析模型。结果显示,利用预处理的反射光谱建立的土壤总氮与总磷模型的决定系数分别是0.842和0.622,其均方根误差分别是0.132g/kg和0.208g/kg。     

Fenton氧化处理马铃薯淀粉废水的试验研究

马铃薯淀粉废水属于中高浓度有机废水。采用Fenton试剂氧化处理马铃薯淀粉废水,试验结果表明:H2O2/Fe2+=5∶2时对马铃薯淀粉废水的氧化处理效果最佳,COD去除量最高达到48.5g COD/mol H2O2;废水pH值在7.02左右时COD去除量最高,因此实际马铃薯废水采用Fenton氧化处理时无需进行pH调节;Fenton氧化反应速率高,且受温度影响小,故该处理方法适用于北方低温马铃薯淀粉废水的处理。     

基于纳污总量控制的流域需水管理思路

《国务院关于实行最严格水资源管理制度的意见》从用水总量控制、水功能区限制纳污、用水效率控制三方面提出了水资源管理的控制红线和实践操作指标。采用“从后向前”的思路,针对水质型缺水问题严重的地区,提出通过纳污总量控制研究需水阈值的工作思路,并提出根据需水阈值实现用水总量控制指标的管理方法,为流域落实最严格水资源管理制度提供参考。     

畜禽养殖业产污系数核算方法的确定

畜禽养殖业产污系数是环境领域重要的基础数据,当前在选取产污系数上差异很大。文章通过分析国内不同畜禽的产污特点,将猪、鸡和牛的产污系数进行合理整合,系数简化,只须统计各畜禽的存(出)栏量,便可得出产污量,结合某大城市的养殖业进行验证和预测。案例预测结果表明:在畜禽种类中,根据确定的猪、鸡和牛的产污系数(COD,TN,TP),估算出该市产生粪污量最多的是牛,占该市主要畜禽粪便产生量的61.2%,其次是蛋鸡13.1%,猪12.3%,肉鸡6.3%,与目前文献中计算方法得出的结果基本一致。     

Kinetic, equilibrium and thermodynamic studies of ternary system dye removal using a biopolymer

In this paper, dye removal ability of sodium alginate (SA) as a biopolymer from ternary systems was investigated. Physical characteristics of SA were studied using Fourier transform infra-red (FTIR) and scanning electron microscopy (SEM). Three textile basic dyes were used as model compounds. The adsorption kinetics, isotherms and thermodynamics were studied. The effect of SA dosage, initial dye concentration and pH on dye removal was elucidated. It was found that adsorption kinetics of dyes followed with pseudo-second order kinetics. In addition, dyes followed with Langmuir, and extended Langmuir isotherm in single and ternary systems, respectively. The thermodynamic data showed that the dye adsorption onto SA was a spontaneous, endothermic and physisorption reaction. Based on the data of present investigation, one could conclude that the alginate being a biocompatible, eco-friendly and low-cost adsorbent might be a suitable alternative for elimination of dyes from colored aqueous solutions.