[Effects of straw returning on maize yield and root system spatial distribution under water stress].

To investigate the effects of straw amendments on the yield and root spatial distribution of maize under water stress, an experiment with rainproof shelter was conducted in the field experimental station of Shenyang Agricultural University in 2016 and 2017. The drip irrigation facilities were used to perform water stress treatments. Straw burying (T) and straw incorporation (T) as two approaches of straw amendments were conducted combined with three depths of 15 cm (D), 30 cm (D), and 45 cm (D) for straw returning, ploughing tillage at above three depths without straw presence as control in this study.

Occurrence, distribution, and attenuation of pharmaceuticals and personal care products in the riverside groundwater of the Beiyun River of Beijing, China.

This study investigated the occurrence, seasonal-spatial distribution characteristics, and attenuation process of 15 pharmaceuticals and personal care products (PPCPs) in riverside sections of Beiyun River of Beijing. The overall PPCP levels both in surface water and riverside groundwater were moderate on the global scale, and showed higher concentrations in the dry season mainly caused by water temperature variation. Caffeine (CF), carbamazepine (CBZ), metoprolol (MTP), N,N-diethyl-meta-toluamide (DEET), diclofenac (DF), bezafibrate (BF), and gemfibrozil (GF) were seven representative PPCPs, because the rest eight studied compounds occurred in low concentrations and less than 15% of the total concentration of PPCPs.

[Distribution Characteristics of Fluoroquinolones Antibiotics in Surface Water and Groundwater from Typical Areas in A City].

In order to investigate the characteristics of 5 typical kinds of fluoroquinolones (FQs) pollution in waters from a city, surface water and groundwater samples from main drainage rivers and typical areas were collected, respectively. The conventional test and FQs concentrations analysis of the water samples were conducted. The results showed the concentration and composition of FQs in groundwater differed substantially from those in surface water.

[Forming mechanism of humic acid-kaolin complexes and the adsorption of trichloroethylene].

The interaction between soil organic components and mineral components was explored in this study. Humic acid and kaolin were used for the preparation of organic-mineral complexes with different contents of organic matter, for experimental study of the adsorption of trichloroethylene. The results showed that the adsorption of trichlorethylene fitted the Freundlich isotherm model.

[Contamination characteristics of fluoroquinolones in different kinds of soil profiles in Southeast suburb of Beijing].

Eighty-six soil samples were collected using Geoprobe soil sampler from 11 borehole profiles of Beijing Southeast suburb. The sampling sites could be divided into 8 kinds of landuse. Physical and chemical properties of samples were analyzed.