Abstract Urban impervious surface rainfall runoff pollution is an important part of non-point source pollution, and the pollutants accumulated on urban impervious surface in non rainy days are the main source of pollutants in rainfall runoff. Taking the first 10 rainfall events in 2015 as an example, the impervious surfaces such as the roof of teaching buildings, campus roads and adjacent main traffic roads within the university campus in southeast Beijing were selected as the research objects to conduct field sampling and Analysis on the natural rainfall and the rainfall runoff pollution. The results show that the first rainfall runoff pollution after winter is serious, and the water quality is inferior to class v. After that, the rainfall runoff pollution is reduced; the severity of water pollution is different at different sampling points; the closer to the building toilet exhaust outlet, the higher the ammonia nitrogen pollution concentration; the existence of pervious surface facilities can reduce the degree of runoff pollution. According to the analysis and research results, some suggestions for controlling and harnessing urban rainfall runoff pollution are put forward.

Abstract Water transport has become one of the most important transport modes in many countries in the world due to its large carrying capacity, low transport cost and low energy consumption. As a hub for land-water transfer, due to frequent trade between ships and land, a large number of domestic sewage and oily sewage are discharged, as well as suspended pollutants generated during construction, etc., as a result, the problem of water pollution in port area becomes more and more serious. In order to carry out the strategy of sustainable development and the concept of green port development, it is imperative to carry out the research and prevention of water pollution in port area. Firstly, the sources and harms of the main water pollutants during the construction and operation of the port are summarized, then the spatial and temporal distribution characteristics of these water pollutants are expounded, finally, the water pollution in the port area is summarized on the basis of the literature analysis, in this paper, the author suggests to introduce ecological engineering to treat the sewage in port area, compares the gap between domestic and foreign ports in drawing up water pollution prevention plan, and points out the defects and deficiencies of the existing water pollution research and prevention in port area.

Abstract In order to reveal the pollution characteristics of the main rivers entering Erhai Lake, from January 2014 to December 2016, taking total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH 3 -N) and chemical oxygen demand (COD cr ) as pollutant indicators, the water quality and quantity of 27 main rivers entering Erhai Lake were monitored and investigated along the way At the same time, combined with the analysis of the precipitation data in the same period and the water quality monitoring data of the lake area, this paper expounds the water quantity and water quality characteristics of the main rivers entering the lake, estimates the pollution load entering the lake, and evaluates the impact of the pollution load entering the Lake on the water quality of the lake area The results show that: a.  from 2014 to 2016, the total water inflow of 27 main rivers into the lake was 287 million~474 million m 3 , and the water inflow in flood season accounted for 79.17%, 74.90% and 61.96% of the annual water inflow respectively. The water inflow into the lake was positively correlated with the precipitation of the basin; b.  On the time scale, the pollutant concentration shows a fluctuating trend of first increasing and then decreasing in the whole year. The water quality in rainy season is generally good, the spatial difference of pollutant concentration is not as obvious as that on the time scale, and the pollutant concentration has a significant negative correlation with the rainfall of the basin; c. The pollution load of Erhai Lake decreases first, then increases and then decreases in the year. The load of Erhai Lake is mainly controlled by the amount of water. The contribution rate of pollution load is in the order of north bank>West Bank>southeast bank. The total nitrogen input of rivers entering the lake is positively correlated with the total nitrogen concentration in the lake area, and the total phosphorus input is positively correlated with the total phosphorus concentration in the lake area. It is an important source of nitrogen and phosphorus in Erhai Lake

Abstract Biochar has the advantages of high carbon content, large specific surface area, well-developed pore structure and good adsorption performance. It is widely used in the fields of soil quality improvement, environmental pollution remediation, carbon sequestration and emission reduction. In view of the practical problems such as low volume density of biochar itself, difficulty in solid-liquid separation, and urgent need to further improve its long-term effectiveness and stability, the biochar composites with higher remediation efficiency for polluted environment were prepared by combining biochar with metal materials, photocatalysts and clay minerals, which attracted much attention. Through a systematic review of the preparation methods and environmental pollution control applications of biochar-based composite materials, and the removal mechanism of organic pollutants in the environment was analyzed, and the future research and development trend of biochar materials was put forward, so as to provide new ideas for the preparation and practical application of high-efficiency biochar composite materials.