煤基腐殖酸对外源砷胁迫下玉米生长及生理性状的影响简

为了筛选用于砷污染土壤治理的煤基腐殖酸，采用盆栽实验研究了施用不同种类和浓度的煤基腐殖酸及EDTA对外源砷胁迫下玉米株高、株鲜重、株干重、根干重、砷积累量、叶片抗氧化酶（POD，SOD和CAT）活性和脯氨酸含量的影响。结果表明，11种供试煤基腐殖酸均促进了玉米生长，提高了叶片POD、SOD和CAT活性。其中6和10号腐殖酸可降低土壤砷活性和显著抑制玉米吸收和积累砷，而8和9号腐殖酸增加了土壤活性砷和显著促进了玉米对砷的吸收和累积，且不同程度地强于EDTA。除8和9号外，其余腐殖酸均可明显降低玉米叶片脯氨酸的含量。EDTA可显著促进玉米吸收和积累砷，且加剧了砷对玉米的危害。因此，8和9号供试煤基腐殖酸可以替代EDTA活化土壤砷，与植物配合以提高砷污染土壤的植物修复速度和效果，而6和10号供试煤基腐殖酸则可用于土壤砷钝化剂，以保证作物产品的安全。     

Optimization of micro-aeration intensity in acidogenic reactor of a two-phase anaerobic digester treating food waste

Micro-aeration is known to promote the activities of hydrolytic exo-enzymes and used as a strategy to improve the hydrolysis of particulate substrate. The effect of different micro-aeration rates, 0, 129, 258, and 387 L-air/kg TS/d (denoted as LBR-AN, LBR-6h, LBR-3h and LBR-2h, respectively) on the solubilization of food waste was evaluated at 35 °C in four leach bed reactors (LBR) coupled with methanogenic upflow anaerobic sludge blanket (UASB) reactor. Results indicate that the intensity of micro-aeration influenced the hydrolysis and methane yield. Adequate micro-aeration intensity in LBR-3h and LBR-2h significantly enhanced the carbohydrate and protein hydrolysis by 21–27% and 38–64% respectively. Due to the accelerated acidogenesis, more than 3-fold of acetic acid and butyric acid were produced in LBR-3h as compared to the anaerobic treatment LBR-AN resulting in the maximum methane yield of 0.27 L CH₄/g VS_added in the UASB. The performance of LBR-6h with inadequate aeration was similar to that of LBR-AN with a comparable hydrolysis degree. Nevertheless, higher aeration intensity in LBR-2h was also unfavorable for methane yield due to significant biomass generation and CO₂ respiration of up to 18.5% and 32.8% of the total soluble hydrolysate, respectively. To conclude, appropriate micro-aeration rate can promote the hydrolysis of solid organic waste and methane yield without undesirable carbon loss and an aeration intensity of 258 L-air/kg TS/d is recommended for acidogenic LBR treating food waste.     

膜电解技术处理含氯及重金属的废酸

采用离子交换膜电解技术处理铜冶炼过程产生的含氯及重金属的废酸。考察了废酸处理工艺、电解温度、电解时间、电流密度和催化剂的添加等条件对处理效果的影响。实验结果表明：采用先沉淀重金属后脱氯的废酸处理工艺，氯离子和铜离子的去除效果均较好;当以钛盐为催化剂时，在电解温度为40 ℃、电解时间为2.0 h、电流密度为825 A/m²的最佳工艺条件下，处理后废酸中的氯离子质量浓度为0.22 g/L，氯离子去除率为98.59%，铜离子质量浓度为0.45 g/L，铜离子去除率为95.08%，其他重金属大部分也得到有效去除。净化后的废酸可回用至铜冶炼的生产过程中。     

茅草添加与温度变化对餐厨垃圾厌氧水解产酸的影响

比较了茅草添加在温度变化条件下对餐厨垃圾厌氧水解过程小分子有机酸产量的影响，提出一种新型餐厨垃圾的资源化方式。研究结果显示，餐厨垃圾在55℃条件下厌氧水解主要产物为乳酸，达到25．7g／L，其干物质转化率可以达到32．1％（gTS），而餐厨＋茅草处理在同样条件下的乳酸产量为20．1g／L，干物质转化率为25．1％。温度下降为37℃后继续进行的的厌氧水解，得到的主要产物是乙酸、丙酸和丁酸，餐厨处理和餐厨＋茅草处理这两者的峰值分别为6．5、2．8、8．0和6．1g／L、2．7g／L和5．9g／L。结果显示茅草添加可以在一定程度上调节水解产物的比例，而温度变化可以调控小分子有机酸的产量。本研究结果表明，厌氧水解是一种有潜力的小分子有机酸生产与餐厨垃圾资源化处理途径。     

羟基乙叉二膦酸镀铜废液的处理及Cu~(2+)的高附加值资源化回收

采用Na BH4还原法将羟基乙叉二膦酸(HEDP)镀铜废液中的Cu~(2+)制备成纳米铜粉,并采用聚丙烯酰胺(PAM)对还原反应后的废液进行絮凝处理。研究了n(Cu~(2+))∶n(Na BH4)、还原反应温度、还原反应时间及PAM添加量对废液中剩余Cu~(2+)质量浓度的影响,并对回收的纳米铜粉进行了XRD和TEM表征。实验结果表明:当n(Cu~(2+))∶n(Na BH4)=4∶6、还原反应温度为50℃、还原反应时间为2 h时,废液中剩余Cu~(2+)质量浓度降低至1.1 mg/L,Cu~(2+)还原率达99.99%;可获得粒径为20~45 nm的近球型、高纯度、由多晶组成的纳米铜粉;当PAM添加量为10 mg/L时,废液中剩余Cu~(2+)质量浓度降至0.35 mg/L以下,达到GB 21900—2008《电镀污染物排放标准》(小于0.5 mg/L)的要求。     

赤霉酸暴露对SD大鼠青春期发育的影响

赤霉酸是目前国内外使用极其广泛的一种植物生长调节剂,但是针对其发育毒性的数据依然较少。本文探讨了赤霉酸暴露对SD大鼠青春期发育的影响。参考国内外环境内分泌干扰物危害的评价方法,将144只初断乳SD大鼠按体重随机分为4组,分别为对照组和1、10、100 mg·kg-1bw剂量组,采用经口灌胃方式对雄鼠连续染毒28 d,雌鼠连续染毒21 d。暴露结束后检测大鼠的体重、食物利用率、雄鼠包皮分离时间/雌鼠阴道开口时间、血清生化指标、脏器系数及组织病理学的变化。研究结果表明,与对照组相比,仅10和100 mg·kg-1bw剂量组雄鼠的肌酐水平显著升高(P<0.01),100 mg·kg-1bw剂量组雌鼠谷丙转氨酶水平有显著升高(P<0.01)。而与对照组相比,所有剂量组均未观察到大鼠的体重、食物利用率、雄鼠包皮分离时间/雌鼠阴道开口时间、脏器系数等指标有显著性差异的改变(P>0.05),组织病理学结果亦显示大鼠重要器官无损害性改变。因此,在本试验给予的剂量范围内赤霉酸染毒不会对SD大鼠青春期发育产生显著影响。     

Characterisation of FOGs in grease trap waste from the processing of chickens in Thailand

Industrial firms that kill and process chickens generate wastewater that contains fat, oil, and grease (FOG). The FOGs are located in the fatty waste that is collected by floatation in grease traps. Chemical and physical characterisation of FOGs would provide useful information that would help in the development of methods designed to decrease the extent of pollution caused by disposal of the waste and to utilise commercially some of its lipid constituents. Employing these methods would enhance the profitability and competitive potential of these commercial organisations. Samples of grease trap waste from 14 firms in central Thailand have been examined. Due to the very different schemes of waste management employed by these firms, the physical appearance of their fatty wastes showed considerable variation. The chemical and physical properties of the FOGs present in these wastes showed considerable variation also. Large amounts of free fatty acids (10–70% as oleic acid) were detected in most of the 14 wastes and palmitic, cis-9-oleic, cis,cis-9,12-linoleic, stearic, and palmitoleic acids were the predominant species of free and esterified acids. Most of the FOGs were solid at temperatures below 40 °C. Many of them contained traces of heavy metals (Cu and Pb) and some contained traces of the pesticides dimethoate and cypermethrin. The content of these potentially hazardous substances would have to be considered very carefully before discarding the fatty wastes and during the development of methods designed to isolate their potentially profitable lipid constituents.     

上海青浦地区大气降水的化学特征

利用上海青浦地区2003—2014年观测的大气降水监测资料,分析该区域12 a以来大气降水的酸化程度、化学组成特征,探讨降水中化学成分的不同来源及相对贡献。结果表明:降水pH年均值为4.43~6.33,酸雨频率为2.6%~86.8%,降水酸化程度大致经历了明显恶化和波动变化2个阶段。降水电导率年均值为1.77~4.01 m S/m,呈下降趋势。降水中各离子雨量加权平均当量浓度顺序为SO_4~(2-)NH_4~+Ca~(2+)NO_3~-Cl~-Na~+Mg~(2+)F-K~+,SO_4~(2-)、NH+4、Ca~(2+)和NO_3~-是降水中的主要离子,占离子总量的83.0%;降水类型由硫酸型向硫酸和硝酸混合型转变。降水离子中的二次组分SO_4~(2-)、NO_3~-和NH_4~+绝大部分来源于人为源,Ca~(2+)、Mg~(2+)和K+主要来自于土壤源和人为源的贡献,Cl~-主要来自海洋源,同时人为源的影响也不可忽视。     

A comparison of pretreatments on release of sugars from sweet sorghum bagasse for bioethanol production

Dilute acid pretreatment and steam pretreatment were evaluated for maximum sugars release and ethanol production from sweet sorghum bagasse (SSB). The fermentation potential of the condensate and hydrolysate obtained from steam pretreatment (10 kg/cm², 10 minutes) and dilute acid hydrolysis (1% (w/w) sulphuric acid, 25% substrate loading) respectively, was checked with Pichia stipitis NCIM 3497 and Debaryomyces hansenii sp. Ethanol production and yield using acid hydrolysate was higher with Debaryomyces hansenii sp. (28.4 g/L and 0.37 g/g respectively) as compared with Pichia stipitis NCIM 3497 (21.9 g/L and 0.29 g/g respectively).     

Effects of humic acids derived from lignite and cattle manure on antioxidant enzymatic activities of barley root

To investigate the effects of humic acids (HAs) on the ability of plants to defend themselves against oxidative stress, barley was hydroponically cultured in the absence and presence of HAs, and the antioxidant enzymatic activities (catalase, superoxide dismutase, ascorbate and glutathione peroxidases) of root tissue were evaluated. Auxin-like structures in HAs, which were extracted from an oxidation product of lignite (LHA) and compost derived from cattle manure (CHA), were identified by pyrolysis-gas chromatography/mass spectrometry (GC/MS) with tetramethylammonium hydroxide. The LHA, which had the lower molecular weight, was more effective in promoting the growth of barley root than CHA. However, the amounts of auxin-like structures in the CHA were much higher than those for LHA. The antioxidant enzymatic activities were initially decreased in the presence of LHA and CHA at the first day after refreshing the culture solution, but were significantly increased on the second day. The CHA sample, which contained relatively high levels of phenolic acids that contained auxin-like structures, was effective in increasing four types of enzymatic activities, while the activities of catalase and ascorbate peroxidase were increased in the presence of LHA, which contains naphthalene derivatives. These results indicate that using HAs as a supplement can be effective in enhancing antioxidation enzymatic activities, while the appearance of the effects is retarded because of the decomposition and release of auxin-like compounds from HAs by organic acids from the plant roots.