By looking up China's 119 literatures during 2000-2016, involving less 1 000 m³·d^-1 water yield of the case of rural domestic sewage treatment engineering, statistical analysis of our country's patterns of rural domestic sewage treatment technique, the effluent standards and six main pollutants index (COD, TN, TP, NH₃-N, SS and BOD₅) removal efficiencies were made. Combining analytic hierarchy process evaluation method,the research progress of the rural sewage treatment technology were predicted. The results show that the treatment of sewage treatment in rural areas is attracting a lot of attention year by year。About 57.26% water yield of the rural domestic sewage treatment facilities were less than 100 m³·d^-1. The main implementation of water quality is acoording to the pollutant discharge standards of urban sewage treatment plants (GB 18918-2002), accounting for 74.99%. The processing technology could be divided into three categories:biology, ecology and combinatorial treatment, among which combination processing technique was used the most. Various technological combinations are the main development direction of rural domestic sewage treatment in the future. The degree of emphasis of current literature technology's water indicator in descending order were COD, TP, NH₃-N, and TN. The degree of difficulty of removal of contaminants in descending order were TN, TP, NH₃-N, and COD.

Microbial fuel cells (MFCs) can convert the chemical energy of organic or inorganic materials into electricity, which can provide electricity while conducting pollution remediation. MFCs has a great prospect in pollution remediation and bio-production of electricity. A systematic review of the researches and the applications of microbial fuel cell in environmental pollution remediation has been carried out. The review covers the areas of heavy metal pollution, organic pollution and inorganic pollution of non heavy metals. The influencing factors of microbial fuel cell, such as electrode material, size, spacing, arrangement way, soil property had been analyzed. The application prospects and shortcomings of microbial fuel cell had also been stated.

Although water erosion is a key factor causing soil degradation, quantification of spatial and temporal variability in rainfall erosivity remains insufficient. Forced by the daily precipitation data from 18 meteorological stations, a monthly rainfall erosivity model was used to estimate the rainfall erosivity of Shandong Province from 1961 to 2010. Its temporal variation and trends were determined by means of Mann-Kendall trend test. Also, the relationship between rainfall erosivity and large-scale climatic oscillation were examined such as the Pacific decadal oscillation (PDO), nino/southern oscillation (ENSO) using the Pearson correlation coefficient, continuous wavelet transform (CWT), cross wavelet change (XWT) and wavelet coherence spectrum (WTC). The results show that annual rainfall erosivity experienced a downward trend during the past 50 years, especially since the 1980s. Summer and autumn rainfall erosivity exhibits the same trend with annual rainfall erosivity during the same periods, whereas upward trends occurs in the spring and winter rainfall erosivity. Seasonally, maximum rainfall erosivity occurs in July and minimum in December. The correlation between rainfall erosivity with the Pacific PDO and ENSO decreases from southeast coast to northwest inland. Rainfall erosivity of Shandong province reveals an approximately 0.8-2 year periodicity, which is similar to those for PDO and ENSO. In high energy area, the rainfall erosivity shows covariance with PDO and ENSO with periodicity of 4-5 years and 3-4 years, respectively. In low energy area, rainfall erosivity has a 4-year periodicity, which is same with PDO, but distinct from ENSO. These results are vital for soil and water conservation, and ecological restoration in Shandong Province.

Zonal and non-zonal vegetation and its related soil samples were collected in Northwest Guizhou Province for analyzing the geochemical characteristics of the elements in soil-Plant system. Results show that low N,P and K concentrations were found in natural soils in study area. Soil Ca and Mg concentrations varied spatially and most trace elements contents were higher than the background values of the country but lower than that of other parts of Guizhou Province. Co was enriched in soils and As had a high background value but not tainted value in the study area where soil was seriously polluted by Cd. Biological absorption coefficients (BAC) indicate that plants had different elements absorption capacity which was mainly controlled by their physiology. Besides, biological absorption coefficients of essential macronutrient had an order of magnitude larger than that of trace elements. Considering to different plants, Pinus massoniana, Rhus chinensis and Iris tectorum maxim had strong abilities to translocate Cd from the root to the epigeal part. Iris tectorum maxim could absorb Cd and As effectively which could be used as a superior plant in the Cd-As combined pollution sites. BAC varied greatly because of different bedrock. BAC level in carbonate area was higher than that in clastic rock area, and the difference was mainly controlled by pH and co-adsorption effect. Furthermore,significant correlation of BAC could be noticed between Co and Cd, and Cu and Zn. Soil P may restrain the adsorption of Cu and Pb by the plants.

In order to study effect of oil pollution on ecological environment in coastal waters of Guangdong Province, the oysters (Crassostrea rivularis) from Guangdong coast during 2001-2010 were collected and the contents of total petroleum hydrocarbons (TPH) in the organisms were determined by spectrofluorometry. A method to grade the ecological risk caused by oil pollution was built for finding the relations between the oil pollution and the Guangdong marine economy. The results indicate that TPH content in oyster samples ranged from <0.2 to 36 mg·kg^-1 (wet weight) with an average value of 9.4 mg·kg^-1, which was significantly higher than their average content of 6.7 mg·kg^-1 detected from 1989 to 1992. Along the coastal waters of Guangdong Province, the highest content of TPH presented in the Pearl River Estuary, which was significantly higher than that in eastern or western coastal part (P<0.01). The TPH was slightly higher in the eastern coast (8.7 mg·kg^-1) than in the western coast (7.6 mg·kg^-1), but the difference was not significant (P>0.10). During the decade, the annual average of TPH content in coastal waters of Guangdong Province had taken a V-shaped variation depending on the time changing. The frequencies of low or medium level ecological risk were 83.3% and 16.7%, respectively, indicating that low ecological risk was generally caused by oil pollution, while medium ecological risk occurred in a very low probability. Annual average of TPH content (dry weight) during 2001-2010 was negatively correlated to annual oil consumption during 2000-2009 (r=-0.738, P<0.02), but positively correlated to annual oil pollutants discharge during 2000-2009 (r=0.752, P<0.02). Temporal variation and spatial distribution of TPH content in the oysters were closely related to the oil pollution control from land source, industrial structure and industry layout along the coastal waters. In addition, it was also significantly influenced by the dramatic increase of coastal industries such as ship building, offshore engineering and oil mining.

Ecological compensation can help motivate farmers to participate in the Grain for Green Project (GGP). For farmers, the willingness to accept (WTA) reflects their rational anticipations of the program. The investigation on the willingness of the farmers to accept compensation should be focused on the overlapping period of the GGP and the new round of GGP. This is owing to the fact that it is very important to the sustainable development of the program. Face-to-face interviews with households were used to obtain data in Jingyuan County in Ningxia Hui Autonomous Region located in the middle of Yellow River basin, and the survey received 398 valid questionnaires in August 2017. Based on these data, a logistic model of double-bounded dichotomous-choice contingent valuation method (CVM) was applied to evaluate farmers' WTA and its influence factors. The results showed that with appropriate economic compensation, 87.2% of the surveyed households were willing to participate in the GGP, and their minimum WTA was 3 180 yuan·hm^-2. There was also a relationship between compensation pattern selection of farmers and their age. Furthermore, 68.8% of respondents willing to obtain cash compensation had an average age of 54. Meanwhile, there were 10.9% and 7% of interviewees with a median age of 49 who preferred technical training programs and low-interest loans, respectively, and job offers were popular by 13.3% of peasants with the average age of 44. At the same time, farmers' willingness was negatively correlated with their education and the medical costs of their families, but positively correlated with the satisfaction of subsidy for GGP. Based on the study, suitable adjustment of compensation standard and patterns, as well as effective policy advocacy, should be strengthened in the future to make more farmers positively and voluntarily participate in the GGP.

In order to explore the mechanism of seed emergence and the factors affecting seedling regeneration of Houpoöa officinalis, three different habitats (coniferous forest, coniferous and broad-leaved mixed forest and broad-leaved forest) were selected in Guiyang Forest Farm in Suichang County. Cross-treatments of the seed coat (removing or preserving the aril) and the wire mesh (cover or not cover) were taken to reveal seed germination and seedling growth characteristics of H. officinalis in different habitats. The results show that:The seed germination rates of H. officinalis were significantly different (P<0.05) in different habitats, and the rates of those under different treatments were significantly different too. The seed germination rate of H. officinalis under prosthetic removal and wire mesh cover in coniferous forest was the highest one; furthermore, no matter with or without wire mesh, the germination rates of H. officinalis under preserving of aril turned out to equal 0; The mortality rate of H. officinalis in the early stage of seedling (4-8 weeks) was the highest one, and it would remain stable with the age growing. In coniferous forest, the retention rate of seedling turned out to be the highest one, but there was no significant difference in retention rate between the different habitats. Differences of habitats can make significant effects (P<0.05) on seedling height and basal stem diameter of H. officinalis. Superiority of seedling height and ground diameter of H. officinalis in coniferous forest was better than those in coniferous and broad-leaved mixed forest,and superiority of H. officinalis in coniferous and broad-leaved mixed forest was better than those in broad-leaved forest; Correlation analysis showed that factors such as air temperature, humidity, light intensity and litter thickness had a significant effect on the germination of H. officinalis seeds. For seedling growth, the important factors were air temperature, light intensity, soil moisture and nutrients. The study revealed that the coniferous forest is the most suitable for the seed germination and seedling growth of H. officinalis, and the aril, animal feeding and habitat heterogeneity are the main reasons leading to the low germination rate and the high mortality of H. officinalis seeds.

pH has important effects on aquatic organisms and element cycling in lakes. The south part of the middle and lower reaches of the Yangtze River is one of the centers of acid rain in the world. The effects of acid rain on lake pH were studied through field investigation and simulated experiment. In the 68 investigated lakes along the middle and lower reaches of the Yangtze River, lake pH had a significant positive correlation with water temperature, dissolved oxygen and chlorophyll a, and a significant negative correlation with total nitrogen, nitrate, dissolved inorganic carbon and turbidity; the average pH value of lakes in acid rain areas was significantly lower than that in non-acid rain areas (P<0.05). The results of the simulated experiment show that the pH value of the low trophic treatment (L) was lower than that of the high trophic treatment (H), and the increasing rates of pH in L treatment was slower than that in H treatment after the single addition of acid rain (pH=2.5, 4.0 and 5.0). The differences of the pH values with three pH treatments of acid rain decreased over time in both L and H treatments. The daily variations of the pH values with different treatments showed the same trend. At the end of the experiment, the pH values with acid rain addition and no acid rain addition had no significant difference in the two trophic treatments. The study indicates that although the increase of the content of chlorophyll a in lakes caused by eutrophication can enhance the buffer capacity to the acid rain, the persistent acid rain could have a potential impact on pH, aquatic organisms and biogeochemical cycles in lakes of this area.

To clarify the influence mechanism of reservoir sediment overlying water temperature, pH, dissolved oxygen, water dynamic water environment change on sediment nitrogen release intensity, sediment slobber samples were collected from Inner Mongolia Xilinguole League river reservoir and 4 factors and 5 levels of single factor release nitrogen simulation tests in chamber were designed. The results showed that:(1)the nitrogen release intensity of sediment was positively correlated with temperature. The total nitrogen release rate of sediment at 25℃ was 1 606.40 mg·m^-2, which was 1.9 times of the total nitrogen release rate under the condition of 5℃. Under the condition of partial acid or partial alkalinity, the total nitrogen release of sediment was also favorable. Under the neutral condition, the nitrogen release intensity of sediment was the weakest, and the fitted curve of nitrogen release intensity with pH showed an upward parabola. Under high intensity disturbance (R=100 r·min^-1), the nitrogen release intensity of sediment was 1 469.5 mg·m^-2, which was 2.1 times of the nitrogen release intensity under the static condition. Under the condition of low dissolved oxygen concentration or anoxic condition, the nitrogen release intensity of sediment is greater, and aerobic condition will inhibit the release of nitrogen in sediment. (2) A variety of linear function of nitrogen release intensity of environmental factors and sediment regression showed that sediment nitrogen release intensity and temperature, pH and hydrodynamic environment factors were the optimal quadratic function curve fitting, and dissolved oxygen in cubic function optimal curve fitting.

Using graphene oxide and ferric nitrate as raw materials, Fe₂O₃@GO polymer was synthesized by impregnation method and applied to the adsorption of As³⁺ in water samples. Mass ratio of Fe/GO, pH and temperature to the adsorption effect were studied. Meanwhile, the two materials were characterized by Raman spectroscopy, FTIR, SEM. All three characterization methods show that iron has been successfully loaded onto graphene oxide. The results show that the removal rate of As³⁺ was positively correlated with the mass ratio of Fe/GO in the complex, and the alkaline and high temperature conditions were more conducive to the adsorption. Besides, the adsorption isotherms of As³⁺ on the two materials conformed to the Freundlich isotherm model, and the adsorption process was better described by pseudo-second-order model. Fe₂O₃@GO polymer compared with GO had greater adsorption capacity under the same conditions. When the initial concentration of As³⁺ was 10 mg·L^-1, the equilibrium adsorption capacity of GO and Fe₂O₃@GO could reach to 17.95 and 31.304 mg·g^-1, respectively.

By simulating Cd-contaminated brown soils in the laboratory, the impacts of single applications of different amounts (20, 40 g·kg^-1) of peanut straw biochar (PB) or cotton straw biochar (CB) and 20 g·kg^-1 phosphate fertilizer (P), as well as the combined application of biochar and P fertilizer, on soil pH and the contents of five forms of Cd in contaminated soils were investigated. The mechanisms of the effects of biochar, phosphate fertilizer and their combination on the bioavailability of Cd in brown soil were analyzed. The results show that the single application of P fertilizer significantly reduced the pH of the soil (by 14.64% compared with CK) and that the application of biochar alone or the combination of biochar and P fertilizer increased the pH of the soil (by 0.99%-24.67% compared with CK). The single application of 40 g·kg^-1 peanut biochar yielded the most significant increase in soil pH. The application of P fertilizer alone significantly reduced the contents of exchangeable, carbonated, and iron-manganese oxide-bound forms of Cd in the soil while increasing the contents of organic-bound and residual forms. The application of biochar alone and the combined treatment significantly reduced the content of the exchangeable form of Cd in the soil and significantly increased that of carbonate-bound Cd (by 49.76%). With the same applied amount of biochar (20 g·kg^-1), the decrease in effective Cd content was higher in the soil treated with the combined application than in that of the single application treatment, and the effect of the combined application of peanut straw biochar and phosphate fertilizer was superior to that of cotton biochar and phosphate fertilizer, with Cd activity coefficients of 0.150 and 0.236, respectively. The combined application of 20 g·kg^-1 peanut straw biochar + 20 g·kg^-1 phosphate fertilizer (P + PB₂) was the most beneficial for reducing the bioavailability of Cd in soil.

A series of electrical resistivity and unconfined compressive strength of hexavalent chromium polluted soil solidified with cement were measured, to reveal the influence of law of age, hexavalent chromium ion content and cement content on unconfined compressive strength and electrical resistivity of the hexavalent chromium polluted soil solidified with cement, and the relationship between the resistivity and unconfined compressive strength. The results show that, unconfined compressive strength and electrical resistivity of hexavalent chromium polluted soil solidified with cement increase with age, and the growth rate is different. The higher the chromium ion content, the lower the unconfined compressive strength and electrical resistivity of hexavalent chromium polluted soil solidified with cement. The more cement content, the greater the unconfined compressive strength of hexavalent chromium polluted soil solidified with cement. The unconfined compressive strength grows with age. When the curing time was shorter, the electrical resistivity of hexavalent chromium polluted soil solidified with cement increased slightly with the increase of cement content in the early age. Unconfined compressive strength(p_u) of samples with 10% cement is approximately linear with electrical resistivity(ρ) of:p_u=0.740 ρ+1.853,R²=0.917. The results of leaching experiments show that the leaching rate of metal decreased and the curing effect becomes better with the increase of curing agent content and curing age. Results of nuclear magnetic resonance revealed that the more hydration producs are embedded in the pore of soil with the increase of cement content, then the pore size range gets smaller. Based on analysis data in micro-pore structures, it shows that the overall smoothness and compactness of the specimens becomes better, and the strength increases with the increase of cement content.

Nitrate is one of the most common pollutants in rural areas because of the excessive use of nitrogenous fertilizer and improper disposal of solid waste and domestic sewage. Groundwater polluted by nitrate have public influences on the safety of drinking water. In order to examine the availability of rice wine acted as carbon source in the practice of nitrate removal from drinking groundwater, in-situ tests with simple sand buckets at two family were carried out, located in the eastern area of Guilin City. In the tests, wine rice was used as a sole carbon source for nitrate removal, and local groundwater was used as influent. The results indicate that nitrate in the effluent can be almost completely removed by denitrification with good stability and the total nitrogen (TN) decreased significantly under the conditions of C/N ratio ranging from 1.5 to 2.2. The intermediates of denitrification including nitrite and ammonia nitrogen had no obvious accumulation. However, acetate and total organic carbon (TOC) may have more accumulation while excess rice wine used. The pH value of the effluent is about 0.8 higher than that of the influent. This study suggests that the method of nitrate removal associated with rice wine as carbon source has a significant practical value for rural families to ensure the safety of drinking water.