Anaerobic digestion of sludge by different pretreatments: Changes of amino acids and microbial community

•Tryptophan protein, and aromatic protein I/II were the key identified proteins. •Cysteine was more correlated with methane production than other amino acids. •The presence of cysteine can promote methane production and degradation of VFAs. •The presence of cysteine can lower ORP and increase biomass activity. •Predominant Tissierella and Proteiniphilum were noted in pretreated sludge samples. Many studies have investigated the effects of different pretreatments on the performance of anaerobic digestion of sludge. However, the detailed changes of dissolved organic nitrogen, particularly the release behavior of proteins and the byproducts of protein hydrolysis-amino acids, are rarely known during anaerobic digestion of sludge by different pretreatments. Here we quantified the changes of three types of proteins and 17 types of amino acids in sludge samples solubilized by ultrasonic, thermal, and acid/alkaline pretreatments and their transformation during anaerobic digestion of sludge. Tryptophan protein, aromatic protein I, aromatic protein II, and cysteine were identified as the key dissolved organic nitrogen responsible for methane production during anaerobic digestion of sludge, regardless of the different pretreatment methods. Different from the depletion of other amino acids, cysteine was resistant to degradation after an incubation period of 30 days in all sludge samples. Meanwhile, the “cysteine and methionine metabolism (K00270)” was absent in all sludge samples by identifying 6755 Kyoto Encyclopedia of Genes and Genomes assignments of genes hits. Cysteine contributed to the generation of methane and the degradation of acetic, propionic, and n-butyric acids through decreasing oxidation-reduction potential and enhancing biomass activity. This study provided an alternative strategy to enhance anaerobic digestion of sludge through in situ production of cysteine.     

中国沿海地区的自然灾害类型及综合区划

作者利用中国沿海地区近４０年或更长时期主导灾害的资料分析其时空特征，特别是空间分布规律。根据综合灾害灾次图的分析指出，中国沿海地区共有３个灾害多发中心，最后将中国沿海地区划分为６个灾害类型区     

废水生化处理中有机物的分析和转化

有机物的种类、含量、物化特性、分子量等性质直接影响废水处理工艺的处理效果。本文综述了近年来废水生化处理中有机物的分析方法及废水生化处理过程中有机物的转化规律。     

Ecological risk assessment from the perspective of soil heavy metal accumulations in Xiamen city,China

Contamination of soils by heavy metals is of rising concern in many cities in China undergoing rapid urbanization. Here, we evaluate the severity of soil contamination by four heavy metals (arsenic, chromium, copper, and lead) at 146 urban and suburban sites within the city of Xiamen, Fujian, China. A multivariate regression model was proposed and developed to simulate heavy metals accumulation in urban and suburban soils, to identify the concentration and spatial distribution of heavy metals in soils, and to assess ecological risks by 2020. Results showed that, overall, Xiamen soils should be subject to low ecological risks due to heavy metals contamination by 2020, the ecological risks for urban soils were greater than suburban soils, nearly half of Xiamen soils are at moderate ecological risks, and many suburban soils experience low ecological risks. The methods demonstrate the potential to predict future ecological risks from heavy metals contamination which could inform pollution prevention and control measures.     

教室声环境的主观反应及烦恼度阈限值的探讨

通过实测和问卷调查，采用模糊数学方法处理调查对象对教室声环境主观反应的所有信息，得出了在教室学习时的烦恼度阈值为49.2dB，并和国家标准值进行了比较。同时还采用了模糊数学综合评判方法－－Ridit分析，对调查结果进行检验，验证了所得烦恼度阈值的合理性，用模糊数学方法处理人们对噪声的主观反应，结果表明，该方法比传统的心理物理法计算更为理想。     

Modeling thermal effect on growth of chinese shrimp, Penaeus chinensis (Osbeck)

A couple of experiments were conducted to estimate the optimal temperature effect on growth of Chinese shrimp (Penaeus chinensis). The equation describing growth-temperature relationship derived from the first experiment with temperature ranging from 16° to 31°C was found linear as the following:

G = -0.005667 + 0.001103 T

,where G and T are daily growth rate and temperature, respectively.The second experiment indicated that the daily growth rate was a quadratic function of temperature at the limits of 27° and 35°C. The equation was

G = -0.339587 + 0.023476 T − 0.000375 T²

.The optimal temperature in terms of maximum growth was 31.26°C.     

石油化工行业废水中有机氯农药残留分析

文章建立了基于HLB固相萃取柱和气相色谱，电子捕获（GC/ECD）分析水体中有机氯农药的方法．并对方法的回收率、灵敏度进行了评价，同时分析了北京市燕山石油化工有限公司五个典型企业排放废水中有机氯农药的浓度，发现存在六六六（HCHs）。滴滴涕（DDT）等有机氯污染物，在5个采样点的水样中有机氯农药的浓度为（0．76-14．S）ng／L。其中六六六、滴滴涕的含量分别为（0．76～10．5）ng/L和（4．89-14．8）ng/L。方法对有机氯农药的空白加标回收率达到74．6％-118．4％。方法检测限为（0．27～2．90）ng/L。     

氯化汞、氯化甲基汞对大鼠肾近曲小管细胞损伤机理的研究

研究了HgCl₂和CH₃HgCl对大鼠游离肾近曲小管细胞的毒性作用及其机理.结果显示,HgCl₂和CH₃HgCl均对肾细胞有明显毒性,表现为细胞内乳酸脱氢酶（LDH）和溶酶体β-葡糖苷酸酶（β-GD）漏出增加,还原型谷胱甘肽（GSH）和蛋白巯基（PSH）含量降低,同时GSH和PSH含量的降低与LDH及β-GD漏出之间呈良好的相关关系.未观察到CH₃HgCl明显诱发肾细胞脂质过氧化作用,HgCl₂仅在50μmol/L以上才出现轻度脂质过氧化效应.     

城市垃圾产生量预测研究

通过对城市生活垃圾产生状况的分析，选取我国西部和东部的典型城市成都、上海进行研究。运用线性回归模型对两城市垃圾量进行预测，为城市建设规划和垃圾综合处理提供依据。