不同预处理方法对剩余污泥性质的影响研究

研究了3种污泥预处理方法(酸、碱和热处理)对污泥性质的影响.结果表明,3种处理方法对污泥均有一定破碎作用,其中碱处理的破碎效果最好,污泥的破碎率最大(约达58.46%),释放的SCOD最高(2 934.9 mg/L).处理后污泥的溶解性有机物的主要成分为蛋白质、碳水化合物和挥发性脂肪酸(三者之和约占总量的80%～90%),碱处理污泥的溶解性蛋白质增加最多(2 058.6 mg/L),而溶解性碳水化合物则是热处理污泥的增加值最大(353.2 mg/L).3种污泥预处理方法均会降低污泥的SS和VSS,其中碱处理效果最好,两者的减少量分别达到25.32%和38.84%,而酸处理效果最差,仅9.05%和1.80%.粒径分析表明,酸、碱处理会减小污泥的粒径、增加污泥的比表面积和提高污泥粒径的均匀性.本研究还对3种预处理方法对污泥的融胞机理进行了分析.     

碱处理促进剩余污泥解的试验研究

研究了热碱水解法对剩余污泥特性参数(溶解性化学需氧量、挥发性脂肪酸、氨氮、pH值与污泥浓度等)的影响.碱的加入减弱了污泥细胞壁对高温的抵抗力,加剧了剩余污泥细胞内有机质的释放与水解,改变了污泥的性质.在反应温度为170℃、pH 13、反应时间为75 min的条件下,溶解性化学需氧量(SCOD)达到了最大融出量17956 mg/L,此时SCOD与总化学需氧量(TCOD)之比为0.65.在pH 13,反应时间为60 min时悬浮固体(SS)、挥发性悬浮固体(VSS)均达到了最大溶解率,其值分别为67%和72%.经热碱水解处理后的剩余污泥SCOD随着原污泥浓度的增大而增大,呈现了良好的线性关系,相关系数R2达到了0.97以上,而且随着pH值的增大,融出率也不断增大,在pH 13时达到最高值672 mg/g.另外,通过正交试验可以得出170℃时各因素对SCOD影响的重要性,依次为污泥浓度、DH值、反应时间.     

Cu~(2+)和Zn~(2+)对日本新糠虾生长、蛋白含量和体内磷酸酶活性的影响

观察了不同浓度(10、20、40和80 μg/L)重金属离子Cu~(2+)和Zn~(2+)对日本新糠虾存活、蜕皮、蛋白含量和体内磷酸酶(碱性磷酸酶和酸性磷酸酶)活性的慢性(30 d)影响.结果显示:(1)Cu~(2+)和Zn~(2+)能明显降低糠虾存活率,金属离子浓度增高,存活率降低,其中Cu~(2+)引起的存活率降低更为明显,在最高浓度(80 μg/ L)Cu~(2+)组中糠虾的存活率仅为同浓度Zn~(2+)组的1/3,两组均明显低于对照组(P<0.05);Cu~(2+)和Zn~(2+)能明显降低糠虾蜕皮次数,最高浓度(80 μg/ L)Cu~(2+)和Zn~(2+)中糠虾的蜕皮数分别为11.00±1.73(次)和11.33±0.58(次),分别约为对照组的55.92%和57.6%.(2)Cu~(2+)和Zn~(2+)均能明显影响糠虾蛋白含量,其中Cu~(2+)的影响力更强,最高浓度(80 μg/ L)Cu~(2+)组糠虾体内蛋白白含量占湿重比为9.78%,仅约为对照组的1/2.(3)Cu~(2+)和Zn~(2+)能明显抑制糠虾体内两种磷酸酶的活力,碱性磷酸酶和酸性磷酸酶活力能作为糠虾监测环境重金属污染(Cu~(2+)和Zn~(2+))的检测指标.     

泉州湾河口湿地土壤脲酶和磷酸酶活性研究

本文对泉州湾河口湿地不同区域(上游、中游和下游)、不同红树植被下土壤脲酶和磷酸酶活性在不同季节的变化规律进行了研究。结果表明:土壤脲酶和磷酸酶活性存在极显著的相关性;两种酶在不同区域间均无显著差异,季节变化均表现为春季大于秋季;有红树植被的土壤脲酶和磷酸酶活性皆大于空地和裸地,土壤脲酶不同红树植被下无显著差异,磷酸酶则表现为百年生桐花树和互花米草显著高于其余植被,秋茄和白骨壤次之。随着土壤垂直深度的增加,脲酶和磷酸酶活性整体上表现为逐渐降低的趋势,湿地土壤脲酶和磷酸酶活性受植被类型和根系生长状况显著影响。以上结果为泉州湾河口湿地的生态修复与环境保护提供了一定的理论依据。     

超声辅助碱解消除沉积物样品多氯联苯检测中有机氯农药的干扰

将超声辅助碱液分解杂质与溶剂萃取相结合,建立了一种快速高效净化、萃取沉积物中多氯联苯(PCBs)的气相色谱分析方法.超声辅助条件下,在2.0 mol.L-1的NaOH甲醇溶液中超声10 min,利用NaOH甲醇溶液的碱解作用即可使有机氯农药(OCPs)完全分解,在利用有机溶剂萃取沉积物中PCBs的同时消除OCPs等干扰.在优化的实验条件下,PCBs各单体的回收率在72.1%—113.7%,相对标准偏差在0.4%—6.3%(n=6)之间.气相色谱图显示,碱解净化后杂质含量显著减少,基线得以明显改善,能满足定性定量检测的要求.利用建立的方法测定了长江口以南海域表层沉积物中PCBs的含量及其分布,24种PCBs的总含量在39.7—493.4 pg.g-1之间,总体上表现为近岸含量较高,同时自长江口沿闽浙沿岸自北向南呈现增高趋势.     

耕作措施对华北夏玉米田土壤温度和酶活性的影响

为探讨长期耕作措施下华北平原夏玉米生长季土壤温度与酶活性的变化规律,本研究对四种耕作处理（免耕秸秆还田NTS,旋耕秸秆还田RTS,翻耕秸秆还田CTS和翻耕秸秆不还田CT）下土壤层次的温度和酶活性进行了测定和分析。结果表明：同一土壤层次的各耕作处理均从6：00．18：00呈现正弦波的变化特征;免耕、旋耕等保护性耕作处理在玉米的生育期内温度变化平稳,日均差均小于翻耕秸秆还田和翻耕秸秆不还田;免耕秸秆还田处理土壤酶活性最高,脲酶活性在夏玉米的3个生育期（播种期、大喇叭口期和收获期）分别高于翻耕秸秆不还田处理28．98％,35．62％和24．9％,碱性磷酸酶分别高32．7％,11．94％和10．39％,脱氢酶分别高27．53％,20．39％和30．53％,旋耕和翻耕秸秆还田处理3种酶的活性也明显高于翻耕秸秆不还田处理;旋耕与翻耕秸秆还田处理脲酶和碱性磷酸酶的差异不显著,脱氢酶的差异达到了5％的差异显著水平;通过研究表明在华北平原采用少免耕为主的保护性耕作措施,可以提高土壤酶活性,降低成本,提高经济效益。     

Phosphorus fractionation in surface water and sediments of industrially polluted freshwater reservoir,India

Industrial pollutions are responsible for alterations in biogeochemical cycling of phosphorus (P) in freshwater systems. The objectives of the present study were to quantify the major P forms and assess the relationship between P fractions in water and surface sediments of Govind Ballabh Pant Sagar (GBPS) reservoir, India. Surface water samples (n?=?48) and surface sediment samples (n?=?48) were collected from six regions of GBPS reservoir in December 2014. The results showed that total particulate phosphorus (TPP) and total dissolved phosphorus (TDP) account for 45%–58% and 42%–55% of total phosphorus (TP) in the surface water. The authigenic-P was found to be more than 84% of the total P in surface sediments. The TPP showed a positive statistical relationship with sedimentary P fractions (authigenic-P, exch-P, and organic-P) indicated the impact of industrial pollution load on inorganic and organic P fractions in water and sediments of GBPS reservoir. The discriminant fraction analysis (DFA) revealed that the exch-P, Fe(III)-bound-P, detrital-P, organic-P, and TPP were sensitive indicators of P dynamics in the industrially polluted GBPS reservoir.     

Effect of a popular Middle Eastern food (Falafel) on rat liver

The aim of this study was to evaluate the effect of short-term consumption of oil and frying oil extracted from falafel patties, and then to study the long-term effect of consumption of falafel patties on rat liver gross morphology and serum liver enzymes. The frying oil quality was assessed using thiobarbituric acid reaction on rat liver homogenate. Frying oil and oil extracted from falafel patties were administered to male Wistar albino rats via gavage for 5 days. Blood samples were collected and the activities of alkaline phosphatase (ALP), aspartate aminotransferase, alanine aminotransferase (ALT), and bilirubin levels were determined. Livers were weighed and gross morphology was assessed. For the long-term effect of falafel consumption, rats were fed falafel patties for 30 days, and then blood samples were collected and assayed for the above-mentioned parameters. Short-term consumption of falafel extracts and frying oil did not cause any significant difference in the liver function tests and liver gross morphology. Whereas, long-term consumption of falafel patties caused a significant increase in ALP, ALT, bilirubin level and increased liver weight/body weight ratio denoting hepatotoxicity. This indicates that consumption of large amounts of falafel on daily basis might lead to hepatotoxicity.     

Anti-implantation and anti-fertility potentials of Anethum graveolens L. extracts in rats

Ovarian hormones affected some enzymes in reproductive tissues. Previous studies revealed Anethum graveolens (dill) seed extract elevated ovarian hormones. In this study, we compared the effects of dill seed and leaf extracts on some enzymes activities and infertility potential. Female Wistar rats were divided into three groups of control, dill seed and dill leaf aqueous extracts treated groups. Experimental groups received 1 mL of 0.5 g kg^?1 of each extract orally for 25 days (five estrous cycles). Estradiol, progesterone, luteinizing hormone, and follicle stimulating hormone concentrations were determined. Uterus and ovaries were removed and their glucose-6-phosphate dehydrogenase, lactate dehydrogenase, and alkaline phosphatase activities were measured. Female rats of three groups were mated with untreated males. Fetuses were extracted in the 20th gestational day and their weights and crown rump lengths were measured. Anti-fertility and anti-implantation activities and fertility indices were calculated. Glucose-6-phosphate activity of dill seed treated group increased 1.6 times in the endometrium and 1.7 times in the myometrium. Progesterone concentration and lactate dehydrogenase activity of serum increased in the dill seed treated group compared to the control and dill leaf treated group. A significant decrease was observed in weights and crown rump lengths of fetuses, weights of placenta, and fertility index of the dill seed treated group compared to the control and dill leaf treated group, but its anti-implantation and anti-fertility indices increased. We suggested that high level of glucose-6-phosphate could entail increased oxidative stress in uterus and ovary. High lactate dehydrogenase activity in serum may affect cell membranes. Higher secretion of progesterone caused hormonal imbalance and produced estrous cycle irregularity. It was concluded that dill seed but not dill leaf extract could induce infertility in an animal model.