The potential to increase soil carbon stocks through reduced tillage or organic material additions in England and Wales: A case study

Results from the UK were reviewed to quantify the impact on climate change mitigation of soil organic carbon (SOC) stocks as a result of (1) a change from conventional to less intensive tillage and (2) addition of organic materials including farm manures, digested biosolids, cereal straw, green manure and paper crumble. The average annual increase in SOC deriving from reduced tillage was 310 kg C ± 180 kg C ha⁻¹ yr⁻¹. Even this accumulation of C is unlikely to be achieved in the UK and northwest Europe because farmers practice rotational tillage. N₂O emissions may increase under reduced tillage, counteracting increases in SOC. Addition of biosolids increased SOC (in kg C ha⁻¹ yr⁻¹ t⁻¹ dry solids added) by on average 60 ± 20 (farm manures), 180 ± 24 (digested biosolids), 50 ± 15 (cereal straw), 60 ± 10 (green compost) and an estimated 60 (paper crumble). SOC accumulation declines in long-term experiments (>50 yr) with farm manure applications as a new equilibrium is approached. Biosolids are typically already applied to soil, so increases in SOC cannot be regarded as mitigation. Large increases in SOC were deduced for paper crumble (>6 t C ha⁻¹ yr⁻¹) but outweighed by N₂O emissions deriving from additional fertiliser. Compost offers genuine potential for mitigation because application replaces disposal to landfill; it also decreases N₂O emission.     

Polyphenylene sulfide based anion exchange fiber: Synthesis, characterization and adsorption of Cr(VI)

A fibrous strong base anion exchanger (QAPPS) was prepared for the first time via chloromethylation and quaternary amination reaction of polyphenylene sulfide fiber (PPS), and its physical-chemical structure and adsorption behavior for Cr(VI) were characterized by FT-IR, Energy Dispersive Spectrometry, TG-DTG, elemental analysis and batch adsorptive technique, respectively. The novel fibrous adsorbent could effectively adsorb Cr(VI) over the pH range 1-12, the maximum adsorption capacity was 166.39 mg/g at pH 3.5, and the adsorption behavior could be described well by Langmuir isotherm equation model. The adsorption kinetics was studied using pseudo first-order and pseudo second-order models, and the t_1/2 and equilibrium adsorption time were 5 and 20 min respectively when initial Cr(VI) concentration was 100 mg/L. The saturated fibers could be regenerated rapidly by a mixed solution of 0.5 mol/L NaOH and 0.5 mol/L NaCl, and the adsorption capacity was well maintained after six adsorption-desorption cycles.     

外源含硫化合物对土壤挥发性有机硫化合物交换通量的影响

通过静态箱采样和Entech7100预浓缩仪-GC-MS分析了半胱氨酸、硫化钠和硫酸钠对土壤吸收或释放羰基硫（COS）、二甲基硫醚（DMS）、二硫化碳（CS2）和二甲二硫醚（DMDS）等4种挥发性有机硫化合物（VOSCs）的影响.结果表明,添加半胱氨酸后,土壤由COS和CS2汇转变为源,DMS和DMDS通量显著增加,且...     

基于氧化还原分析的硫化矿尘爆炸压力预测*

为探究可应用于生产现场的硫化矿尘爆炸压力预测方法,基于硫化矿尘爆炸反应机理和粉尘引爆试验数据对硫化矿尘的氧化还原成分与其爆炸压力的相关关系进行分析。研究结果表明:硫化矿尘的还原成分指数与其爆炸压力的相关性极高,尤其是与其爆炸压力峰值的相关性系数高达0.993。整合研究结果形成的硫化矿尘爆炸压力和爆炸压力峰值计算和预测模型,可为金属矿山的硫化矿尘爆炸预防提供决策依据。     

长江中下游地区21世纪气候变化情景预测

利用IPCC数据分发中心提供的7个模式的模拟结果,分析了由于人类活动影响,温室气体(GG)增加以及温室气体和硫化物气溶胶(GS)共同增加时,长江中下游地区未来50～100年的气候变化情景.结果表明,长江中下游地区21世纪的未来温度变化与全球和全国一样,都将呈增加的趋势.GG作用下,2050年和2100年长江中下游地区的变暖幅度分别为2.2℃和4.5℃左右,比全国以及东部和西部地区的变暖幅度小;GS作用下2050年和2100年,其分别为1.2℃和3.9℃,总体上,长江中下游地区的变暖幅度低于全球与全国的变暖幅度.各个季节相比,春季和冬季的增温幅度最大,夏季最小,在两种情形下,长江中下游地区21世纪中期夏季温度将分别增加2.3和0.8℃,2100年将分别增加4.1和3.1℃.对降水变化的分析表明,GG作用下,长江中下游地区与全球、全国以及中国西部和东部地区相比,降水增加的幅度最大;GS作用下,降水增加趋势不明显;综合7个模式的模拟结果,GG作用下,春季和秋季降水增加最明显,夏季次之;GS作用下,长江中下游地区的年平均降水变化不明显,夏季降水增加.同时,本文还对长江中下游地区21世纪中期和末期的温度和降水变化的地理分布进行了分析,两种情形下,都是长江以北的增温幅度大于长江以南.GG作用下,春季长江中下游地区21世纪中期降水将增加5%～7.5%,夏季则是长江下游地区降水增加较大,将增加10%,而长江中游地区降水增加不明显;21世纪末,春季和夏季长江中下游地区的降水增加幅度都将加大,尤其是长江以南地区的降水增加最明显;考虑GG和GS的共同影响后,长江以南的地区降水增加,长江以北地区降水减少.     

外源硫酸盐对武汉南湖表层沉积物磷形态的作用

采用室内模拟实验,选取武汉市南湖表层沉积物及相应上覆水,研究了硫酸盐的输入对沉积物磷形态的影响.结果表明,硫酸盐输入水体后提高了沉积物磷的迁移活性,导致上覆水中总磷(TP)、溶解性正磷酸盐(SRP)含量升高,上升幅度随硫酸盐输入量的增加而增加.硫酸盐扩散到沉积物后,先是生成酸可挥发性硫(AVS),进而转变成铬还原硫.硫酸盐输入提高了沉积物pH值,而使Eh降低.沉积物不同磷形态对外源硫酸盐的响应有所差异,二钙磷(Ca2-P)含量随输入硫酸盐浓度的增加而增加,含量最高的铁磷(Fe-P)为800mg/kg左右,占总磷的51.4%~56.6%,受硫酸盐的影响极显著(P<0.01),在沉积物中含量降低而向上覆水中释放.上覆水中溶解性铁和TP、SRP均呈显著正相关.硫酸盐对沉积物中闭蓄态铁磷(O-Fe-P)也产生显著影响(P < 0.05),总体而言是促进其释放.     

氯化镁微胶囊泡沫作用机理及阻化效果研究

针对现有硫化矿石自燃防治技术在应用中存在的不足,提出了采用氯化镁微胶囊泡沫防治硫化矿石自燃火灾的新思路。首先阐述了氯化镁微胶囊泡沫的特性与作用机理,然后通过实验,制备了微胶囊与微胶囊泡沫并以正交试验确定了制备微胶囊泡沫的最佳配方:微胶囊与水质量比为1∶5、ABS浓度为6 g/L、稳泡剂X浓度为6 g/L;最后采用对照实验,以温度与阻化率为优选依据,对氯化镁微胶囊泡沫、氯化镁溶液与水三者的阻化效果进行比较。结果表明在氯化镁微胶囊泡沫的作用下,硫化矿石堆的温度上升最慢,阻化率最高,达到81.6%,阻化效果优于其他两种阻化剂。     

Ozone kinetics of dimethyl sulfide in the presence of water vapor

The outdoor smog chamber was used to thorough investigate the rate constants of gas-phase reaction between dimethyl sulfide （DMS） and ozone （O3） under conditions of relative humidity 55.0%-67.8% at （296±2）K for the first time. The rate constants were measured, at a total pressure of 1 atm, to be （10.4±0.2） × 10^-19 cm^3·molecule^-1·s^-1 at relative humidity of 67.5%±0.3% at 298K, （10.1±0.1） × 10^-19cm^3·molecule^-1·s^-1 at relative humidity of 66.5%±0.5% at 296K, （7.75±0.39） × 10^-19cm^3·molecule^-1·s^-1 at relative humidity of 64.8%± 0.1% at 294K and （3.42±0.21） × 10^-19cm^3·molecu- le^-1·s^-1at relative humidity of 55.8%±0.8% at 295K. Base on these results, it is possible to see the reaction of O3/ DMS in the presence of water vapor as an important sink for DMS in the earth atmosphere.     

我国硫化氢职业中毒现状、原因与对策

分析了硫化氢的主要存在场所,对近年来硫化氢职业中毒行业事故进行汇总并分析了易发事故行业中毒原因,介绍了当前硫化氢中毒的预防措施及我国管理政策。指出硫化氢职业中毒事故的发生与国家的监管力度、企业的重视程度以及工人的自我保护意识密切相关,相关部门加大监管力度是防治硫化氢职业中毒的一个不可忽视的环节,同时应加大力度开发防治硫化氢中毒及应急处理的技术与装备。     

毒气泄漏事故应急用个体呼吸防护用品防护效果研究

本文对毒气泄漏事故应急过程中公众常用的个体呼吸防护用品的防护效果进行了研究.针对硫化氢气体,利用无机气体防护时间检测系统,测试研究了滤毒盒、简易防护口罩、毛巾等个体防护用品在不同工况下的防护性能,试验结果表明,有毒气体浓度及温湿度两种工况条件均对个体防护用品的防护时间有较大影响,滤毒盒的防护效果远好于简易防护口罩,毛巾的防护效果较差,在此基础上进一步分析了毒气泄漏事故应急过程中个体呼吸防护用品的选择策略.本研究可为建立个体防护对策的选择方法提供基础数据和参考.