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Surface runoff has dropped sharply in the mountainous area of the Hutuo River, posing a huge challenge to the sustainable use of groundwater in the North China Plain (NCP). The Taihang Mountain area is the main recharge source area of groundwater in the NCP. An in-depth study of spatial variation characteristics, influencing factors, and sources of hydrogeochemical characteristics of surface water and groundwater in the mountainous area of the Hutuo River can facilitate a comprehensive understanding of regional water resource status and sustainable utilization of water resources. Based on isotopic, hydrogeochemical, and mathematical statistics methods, this study analyzed spatial variation of hydrochemical characteristics in surface water and groundwater and its sources and main controlling factors. The results showed that the river water, well water, and spring water were all recharged by atmospheric precipitation in the mountainous areas of the Hutuo River. Under the combined influence of natural factors and human factors, the hydrogeochemical characteristics of river, well, and spring water showed large spatial differences. On the whole, the hydrochemical types of mainstreams were relatively concentrated. In the upper and lower mining reach areas, the mainstream water chemical type was dominated by Ca·Mg-SO 4 ·HCO 3 , whereas that in the natural vegetation area (middle reach:between Qingshui River and Longhua River) was dominated by Ca·Mg-HCO 3 ·SO 4 . In the upper stream, the main hydrochemical type of the Yukou River and Ehe River tributaries was Ca·Mg-SO 4 ·HCO 3 , which was consistent with that of the main stream. The main hydrochemical types of the Muma River and Qingshui River tributaries were Ca-HCO 3 , Ca·Mg-HCO 3 , and Ca·Mg-HCO 3 ·SO 4 in the midstream. The main hydrochemical types of the Mianhe River and Yehe River tributaries were Ca-SO 4 , Ca·Mg-SO 4 , and Ca·Mg-SO 4 ·HCO 3 . Mineral dissolution was still the main controlling factor for the hydrochemical characteristics of surface water and groundwater in the mountainous area of the Hutuo River. The contribution rates were 69.86% and 18.84% for mineral dissolution and human activities, respectively. Therefore, in the future, water resource utilization in the upper reaches of the Hutuo River should not only consider the issue of water quantity but also a series of water environment problems such as nitrate pollution and mining pollution caused by human activities.

The Yongding River basin is an important water conservation and ecological barrier area in the Northwest of Hebei Province. Reduced runoff and deterioration of the water environment in this area have become increasingly prominent under the effects of climate change and intensive human activities. Clarifying the chemical characteristics and factors of surface water and groundwater in the upper Yongding River basin can provide data and support for the sustainable use of water resources. Stable isotopes of hydrogen and oxygen ( δ 2 H and δ 18 O) were used to study the sources of surface water and groundwater. Mathematical statistics and hydrogeochemical methods were then used to analyze the regional hydrogeochemical processes and factors of surface water and groundwater. The results showed that precipitation was the main source of surface water and groundwater. Under the effects of natural factors and human activities, the Yang River and Sanggan River basins exhibited significant differences in surface water chemistry. The sub-basins were ranked by ion concentration as follows: Sanggan River>Yang River. The main cation and anions of the Sanggan River basin were Na + , Cl - , and SO 4 2- , while in the Yang River basin, Ca 2+ and HCO 3 - were the most common. The water chemistry of the Sanggan River exhibited greater variation than that of the Yang River. Surface water chemistry were mainly controlled by mineral dissolution and evaporation, but human activities were reflected in different sub-basins. Surface water in the Sanggan River basin was affected by industrial wastewater discharge, while that of the Yang River basin was affected by agricultural production and cities. However, the continuous increase of Cl - and SO 4 2- concentrations, caused by industrial wastewater discharge and acid rain, was the limiting factor for sustainable use of surface water resources. In future, surface water in Sanggan River basin should be used with consideration to the effects of both total salinity and chemical composition of the water, while in Yang River, a focus should be placed on total salinity. The use of surface water resources in accordance with local conditions is an effective measure for the sustainable use of water resources and the restoration of groundwater levels in this region.

Heavy metals in farmland soil are one of the most hazardous pollutants in the environment, owing to their universality and irreversibility. Modified biochar has been widely used in the adsorption and immobilization of heavy metals in soil, and its applicability is mainly determined by the types of heavy metals, pollution levels, and soil environmental conditions. Soil pollution is gradually becoming more complex and diversified, and heavy metal pollutants mostly occur in the form of compound pollution. However, most studies have focused on single heavy metal pollutant or the addition of heavy metal to soil. This study used rice straw as a raw material to prepare biochar, and modified it with K 3 PO 4 , KMnO 4 , and NaOH. The physicochemical and structural characteristics of the modified biochars were detected using a BET accelerated surface area and porosimetry system, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and the biochars were then analyzed for the availability and forms of Cd and Cu in soils contaminated with heavy metals in the mining area. The results showed that the surface roughness of the modified biochar increased to different degrees with increases in specific surface area and pore volume, with the NaOH modified biochar showing the most significant increases from 4.96 m 2 ·g -1 to 60.79 m 2 ·g -1 , and from 0.02 cm 3 ·g -1 to 0.12 cm 3 ·g -1 , respectively. The pore diameter changed in the opposite direction. The absorption peaks of the functional groups of the modified biochar were all changed, with K 3 PO 4 modified biochar exhibiting the greatest degree of change. The addition of biochar significantly improved the soil pH value ( P <0.05), and the pH value of the soil treated with K 3 PO 4 modified biochar exhibited the largest increase. With an application of 20.5% K 3 PO 4 modified biochar, the availability of Cu and Cd in the soil was significantly reduced, by 75.44% and 67.70%, respectively. The immobilization efficiency of Cu was much higher than that of Cd. The best immobilization efficiency of Cu and Cd in soil was achieved with K 3 PO 4 modified biochar. With an addition of 2% K 3 PO 4 modified biochar, the immobilization efficiency of Cu and Cd was 61.06% and 4.12%, respectively. In summary, K 3 PO 4 modified biochar had a better immobilization effect on both Cu and Cd in compound contaminated soil.

In order to study the surface energy budget of the cropland in North China Plain, this paper discussed the characteristics of heat and CO2 fluxes of the cropland during the winter wheat growing, and then simulated the dynamic change of the flux of heat and carbon by SiB2 (simple biosphere model Version2) based on the observational data from 2005-10-10 to 2006-06-10 of Weishan experimental station. The results showed that the heat and CO2 fluxes put up obvious inter-daily variations in the course of the wheat growing and their maximum appeared at around midday. The diurnal variations of them are obvious too, and the net radiation, latent heat flux and the heat flux of underlaying surface during the winter were minimum while they were maximum in the anthesis and maturation of wheat; and the sensible heat flux during the winter was maximum and it was minimum in the shooting and heading period of wheat; while the CO2 flux during the shooting and heading period of wheat was the maximum and it was minimum during the winter. Finally, SiB2 model was used to simulate the heat and CO2 fluxes and the surface temperature based on the data of Weishan observation station and the results showed that the model was good at simulating, the simulated net radiation, latent heat flux, sensible heat flux, the heat flux of underlaying surface, CO2 flux and surface temperature were shown to be basically in agreement with observations with their square of related coefficient being 0.985, 0.637, 0.481, 0.725, 0.499 and 0.877 respectively. In addition, the average simulated value of net radiation, latent heat flux and the heat flux of underlaying surface were lower than the observed value and others were higher than the observed ones. In addition, the fluxes and surface temperature were simulated by SiB2 in the different stages of winter wheat and the results showed that the accuracy of the model in the shooting and heading period of wheat was better than the other two stages and the leaf area index was sensitive to the model.

Aimed at controlling the nitrogen loss caused by the ammonia gas emission during composting, the mixtures of magnesium hydroxide [Mg(OH)2] and phosphoric acid (H3PO4) were added into composting materials of swine manure and cornstalk. After 26 d composting, ammonical nitrogen and total nitrogen were improved obviously,which were 10.7 g x kg(-1) and 36.9 g x kg(-1) respectively in amended treatment (B), while they were 7.7 g x kg(-1) and 26.8 g x kg(-1) in un-amended trial. By analysis of the total organic carbon, t suggested that amendments accelerated the degradation of organic matter, germination index test showed the maturity of trial B(96%) was better than trial A(82%) in final compost. The scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis confirmed the existence of struvite (MgNH4PO4 x 6H2O). These results indicated that Mg (OH)2 and H3PO4 could accelerate the degradation of organic matter, and reduce the ammonia emission by struvite crystallization reaction.

A bacteria strain XSP-1 capable of utilizing phoxim as sole carbon source was isolated from sludge collected from a pesticide manufacturer. It was preliminarily identified as Delftia sp. according to its physiological-biochemical analysis and the similarity analysis of its 16S rRNA gene sequence (GenBank Accession No. EF061135). Strain XSP-1 could degrade 100 mg/L phoxim within 7 h completely. The optimal pH and temperature for degradation were 7.0 and 35 degrees C respectively. The degrading rate showed a positive correlation to the initial inoculum size. Strain XSP-1 also showed good degrading performance against methyl parathion, chlorpyrifos and fenitrothion. PCR detection with degenerated primers designed according to the conserved sequences of reported mpd gene did not find target band, but it needs further study to verify whether strain XSP-1 harbors a new mpd gene.

JQL4-5 (Sphingomonas sp.), a fenpropathrin-degrading strain isolated from soils exposed to repeated pesticides contamination, was used in this work to study factors affecting its degrading capacity of fenpropathrin in soil microcosms. In sterilized soil, the degradation rates of fenpropathrin by JQL4-5 were faster than those in unsterilized soil. Various factors, including soil pH, temperature, initial fenitrothion concentration, and inoculum size influenced its degradation efficiency. The addition of 10(6) CFU x g(-1) was able to degrade varying concentrations (10-200 mg x kg(-1) soil) of fenpropathrin over a temperature range of 20-40 degrees C and pH range (6.5 - 7.5). The results indicated that strain JQL4-5 has potential use in bioremediation of fenpropathrin-contaminated soil.