Utilization of nano/micro-size iron recovered from the fine fraction of automobile shredder residue for phenol degradation in water

Phenol removal by n/m Fe in the presence of H₂O₂ was highly effective. Increasing the amounts of n/m Fe and H₂O₂?increased the phenol removal rate. Phenol removal was decreased with an increase in the concentration of phenol. The natural pH (6.9) of the solution was highly effective for phenol removal. The pseudo-first-order kinetics was best fitted for the degradation of phenol. The study investigates the magnetic separation of Fe from automobile shredder residue (ASR) (<0.25 mm) and its application for phenol degradation in water. The magnetically separated Fe was subjected to an ultrasonically assisted acid treatment, and the degradation of phenol in an aqueous solution using nano/micro-size Fe (n/m Fe) was investigated in an effort to evaluate the possibility of utilizing n/m Fe to remove phenol from wastewater. The prepared n/m Fe was analyzed by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The effects of the dosages of n/mFe, pH, concentration of phenol and amount of H₂O₂ on phenol removal were evaluated. The results confirm that the phenol degradation rate was improved with an increase in the dosages of n/mFe and H₂O₂; however, the rate is reduced when the phenol concentration is higher. The degradation of phenol by n/mFe followed the pseudo-first-order kinetics. The value of the reaction rate constant (k) was increased as the amounts of n/m Fe and H₂O₂ increased. Conversely, the value of k was reduced when the concentration of phenol was increased. The probable mechanism behind the degradation of phenol by n/m Fe is the oxidation of phenol through hydroxyl radicals which are produced during the reaction between H₂O₂ and n/m Fe.     

Upgrading VFAs bioproduction from waste activated sludge via co-fermentation with soy sauce residue

SSR addition upgraded VFAs production from WAS. Structure modification by pretreatments led to performance distinctions. Distinctions in microbial community was observed by pretreatments selection. Up to 0.49‒0.65 billion €/year of market value potential was preliminary estimated. Conditioning of extra carbon sources has been widely reported to facilitate fermentation of waste activated sludge (WAS). Soy sauce residue (SSR) was a relatively untapped carbon source for sludge conditioning. This batch study aimed to evaluate the possible implementation of SSR for volatile fatty acids (VFAs) production from WAS. To upgrade the bioavailability of feedstock, three typical pretreatment methods were conducted, i.e., ammonium hydroxide (AH), sulfuric acids (SA) and thermal assisted alkaline (TA). AH pretreated test (AH-PT) outperformed due to a relatively strong structure decomposition of cellulosic materials as revealed by infrared spectroscopic analysis and crystal index. As a result, performed a high hydrolysis rate of 4449 mg COD/d, 1.12-1.23-fold higher than that in TA and SA pretreated tests (TA-PT and SA-PT), and 7.8-fold higher than that in the Control test. Meanwhile, a volatile fatty acids (VFAs) contribution of 401.2 mg COD/g SSR∙L and a maximum acidification rate of 3.59 d^-1 was recorded, with a high sum proportion of mall molecular acetic and propionic 82.2%, 11% ‒70% increase over the other three tests. Besides, speciation process characterized with functional genus differentiation was identified by microbial diversity and distribution investigation and canonical correspondence analysis (CCA). Finally, a potential market value of 0.49‒0.65 Billion €/year was preliminary estimated, showing promise of resource recovery from both WAS and SSR instead of extensive disposal.     

哈药污泥的化学组成及农田应用安全性研究

通过对哈药总厂污水处理车间排放的污泥进行化学成分及施入土壤后重金属元素在土壤及水稻子粒中残留的分析,探讨该污泥能否应用于农田及适宜的用量.试验结果表明,污泥中有机质含量高,达800mg/kg,全氮含量达7%左右.重金属元素含量均明显低于农用污泥中污染控制标准值.大剂量施入土壤后,子粒中重金属元素的残留量与常规施肥无明显差异.随污泥用量的增加,土壤中有机质的含量明显提高,重金属元素除汞和锌有较大幅度提高外,其他元素差异不大.     

Toxicokinetics,metabolism, and microsomal studies of chlorpropham in rats

A study on the toxicokinetic behavior, metabolism of chlorpropham, and its effect on cytochrome P₄₅₀ from liver microsomes was carried out in albino rats after a single and consecutive oral administration at 500?mg?kg^?1 body weight for 10 and 20 days. Chlorpropham was detected in the blood at 0.08?h (11.43?±?1.72?µg?mL^?1) reaching a maximum concentration at 2?h (30.90?±?2.55?µg?mL^?1) and a minimum at 48?h (1.95?±?0.20?µg?mL^?1) after a single oral administration of 500?mg?kg^?1. The absorption rate constant (K _a) was 0.66?±?0.48?h^?1. The Vd _area (18.01?±?2.78?L?kg^?1) and t _1/2 β (12.23?±?1.96?h) values suggested a wide distribution and long persistence of the compound in the body, respectively. The higher Cl_R (0.82?±?0.00?L?kg^?1?h^?1) compared to Cl_H (0.18?±?0.02?L?kg^?1?h^?1) value indicated that a major portion of chlorpropham was excreted through the urine (30%) compared to the faeces (2.81%). Chlorpropham residue was detected in all tissues of rat at 0.25?h while its metabolite, meta-chloroaniline was detected in liver, kidney, heart, lung, and spleen tissue at 0.25?h. Meta-chloroaniline was not detected in skeletal muscle, brain, fat, and stomach tissue at any time of the observation period. Maximum concentrations of chlorpropham and meta-chloroaniline were detected at 2?h (except in the spleen), and minimum concentrations of chlorpropham at 24 (heart, lung, spleen, skeletal muscle, and stomach) and 48?h (liver, kidney, brain, and fat tissue) respectively; and meta-chloroaniline at 24?h (except heart and spleen). The tissue half-life of chlorpropham in rat varied from 3.80 to 11.60?h. Repeated oral administration of chlorpropham at 500?mg?kg^?1 for 10 and 20 days caused an induction of the liver microsomal pellet of rat.     

Methylobacterium sp. YAL-2对乙酰甲胺磷的降解特性

从有机磷生产厂家的下水道污泥中分离出一株对高浓度和低浓度乙酰甲胺磷都具有高效降解能力的寡营养菌YAL-2,根据形态、生理生化和16S rRNA基因系统发育分析,将菌株YAL-2鉴定为Methylobacterium sp.降解特性实验表明,菌株YAL-2能利用乙酰甲胺磷为唯一碳源生长和降解;在添加了甲醇的无机盐培养基中,84 h可完全降解300mg L-1乙酰甲胺磷,24 h将50 mg L-1和10 mg L-1乙酰甲胺磷降至非检测水平;4 d能完全去除100 mg L-1甲胺磷,5 d分别降解58.4%和40.6%的100 mg L-1乐果、敌敌畏.小青菜农药残留去除实验显示,菌株YAL-2可在7 d内将乙酰甲胺磷和甲胺磷将至限量水平.结果表明,将菌株YAL-2应用于保证果蔬等食品的食用安全是可行的.     

水稻中氟虫双酰胺及其代谢产物的超高效液相色谱残留分析方法

采用超高效液相色谱法分析了氟虫双酰胺及其代谢产物在田水、土壤、稻秆、糙米和稻壳中的残留.水样以乙酸乙酯为萃取溶剂,液-液分配净化;土壤样品以丙酮为提取剂,液-液分配净化;水稻样品经乙腈提取,NH2-Carb柱净化.对水稻和环境中的氟虫双酰胺及其代谢产物进行不同水平的添加回收率实验,方法的回收率在78.2%—104.8%之间,相对标准偏差为1.1%—4.4%.氟虫双酰胺及其代谢产物的最小检出量在0.004—0.02 ng,其在稻田水中的最低检测浓度为0.0008—0.0009 mg.L-1,在土壤、稻秆、糙米、稻壳中的最低检测浓度为0.001—0.003 mg.kg-1.     

阿维菌素在棉花和土壤中的消解规律研究

在济南和合肥开展了阿维菌素在棉花和土壤中残留田间试验,采用超高效液相色谱-质谱联用分析方法,研究了阿维菌素在棉花和土壤中的消解动态和最终残留。试验结果表明：阿维菌素在添加浓度水平为2～50μg·kg-1,平均回收率为78.2%～98.0%,相对标准偏差（RSD）为2.6%～6.4%;阿维菌素在棉叶和土壤中的消解动态符合一级动力学方程,其在棉叶中的半衰期为0.7～0.8 d,在土壤中的半衰期为0.9～1.4 d;阿维菌素在棉籽和土壤中的最终残留量均为未检出。建议按照按推荐剂量16.2～24.3 g·hm-2施药,施药1次,其在棉籽中的残留是安全的。     

噻嗪酮在番茄和土壤中的残留分析

建立了一种固相萃取-反相高效液相色谱检测噻嗪酮在番茄和土壤中残留的方法.方法的添加回收率为79.8%-109.2%,变异系数为2.8%-7.0%.最小检出量为6×10-11g,最低检测浓度为0.01mg·kg-1.消解动态研究表明,噻嗪酮在番茄中的消解半衰期为3.27-3.83d,在土壤中的消解半衰期为10.57-12.91d.最终残留试验研究表明,在嚷嗪酮含量为432g(a.I.)-ha-1与216g(a.I.)·ha-1,施药2次和3次的情况下,噻嗪酮在番茄中的最终残留2d为0.076-0.237 mg·kg-1,3d为0.013-0.105mg·kg-1噻嗪酮在土壤中的最终残留2d为0.067-0.294mg·kg-1,3d为0.044-0.197mg·kg-1.     

14C-甲磺隆在土壤中的可提态残留、结合态残留和矿化

在实验室培养条件下,从质量平衡角度,研究了¹⁴C-甲磺隆在7种土壤中形成结合残留(¹⁴C-BR)、可提态残留(¹⁴C-ER)以及矿化为¹⁴CO₂的规律;同时对¹⁴C-BR的主要影响因子及其在腐殖质中的分布规律进行了研究.结果表明:①¹⁴C-甲磺隆在土壤中形成的¹⁴C-ER,其含量与土壤pH呈显著正相关.甲磺隆母体化合物在7种土壤中 的半减期为13.3～66.6d,降解速率常数λ(d-1)与pH呈显著负相关.②¹⁴C-甲磺隆在7种土壤中形成的¹⁴C-BR,其含量在培养初期的20d内,与土壤pH呈显著负相关且与土壤粘粒含量呈显著正相关;而培养20d后,¹⁴C-BR的含量只与土壤pH呈显著负相关.pH是¹⁴C-甲磺隆在土壤中形成BR的主要影响因子.¹⁴C-甲磺隆在7种土壤中的¹⁴C-BR的最大值约为引入量的19.3%～52.6%.③在整个培养试验过程中,7种土壤中的¹⁴C-BR主要分布在富啡酸和胡敏素中,但其分布在胡敏酸中的相对百分比较小.因此,在¹⁴C-甲磺隆形成BR的过程中,富啡酸的作用＞胡敏素>胡敏酸.④在整个培养试验期间(180d),¹⁴C-甲磺隆在7种土壤中通过三嗪杂环开环矿化为¹⁴CO₂的量约占引入量的12.9%～27.0%,其在碱性土壤中更难被矿化为¹⁴CO₂.     

上海崇明岛农田土壤中多氯联苯的残留特征

在上海崇明岛采集了101个耕层土壤样品,利用GC-μECD测定了8种多氯联苯(PCBs)浓度,并对其进行多元统计分析,探讨了其可能的污染来源.结果表明,样品PCBs浓度范围为n.d.~261ng/g,均值为56.0ng/g,低氯联苯含量和检出率均较高.不同土壤利用方式对PCBs残留量有一定影响,表现为水稻田土壤>大棚蔬菜西瓜田土壤>露天蔬菜西瓜田土壤.主成分分析和相关性研究结果显示,土壤中低氯联苯同系物间相关性较好,污染来源可能为同一类.