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To meet the requirements of automatic precision irrigation for tomato cultivation on the coco coir slabs, a transpiration feedback intelligent irrigation system was developed in this study. The system included the substrate water content detection component, the communication component, the decision component, and the irrigation component. The transpiration detection component detected tomato transpiration based on the load cell, the decision component established the precision irrigation control model based on the water holding capacity of coco coir and tomato transpiration, which accurately controlled the pump start-up and turn off, so that the irrigation amount changed with the transpiration rate. The precision irrigation control model had two modes which were normal irrigation mode and flushing mode. When transpiration amount and Electrical Conductivity (EC) value were high, the flushing mode was called, otherwise, the normal irrigation mode was called. The day was divided into four periods. The first period was from sunrise to midday, when the transpiration rate gradually increased, the water content of the substrate should be gradually irrigated to the water holding capacity; the second period was from midday to the end of flushing, when the instantaneous water content of the substrate should be maintained above the water holding capacity to flush the excess salt in the substrate; the third period was from the end of flushing to a moment before sunset, at which time the water content of the substrate should be maintained around the water holding capacity to meet the needs of high transpiration rate in the afternoon, to ensure that there was sufficient water and nutrients to meet the needs of tomato photosynthesis; the fourth period was from the moment before sunset to the second day before the start of irrigation, at which time the water content of the substrate should gradually fall back to the lower limit of the appropriate water content, so that air entered the substrate to ensure the root respiration and normal growth. The second period was the flushing stage, and there was no flushing stage under normal irrigation mode. The water contents in the coco coir slabs were kept at the appropriate range, and a certain irrigation-to-drainage ratio maintained, to benefit the root growth of tomato and absorption of nutrients, and solved the drought stress caused by insufficient irrigation and nutrient waste caused by too much irrigation. The effect of the transpiration feedback intelligent irrigation system was tested, and an irrigation system controlled by light radiation accumulation which was designed by the RIDDER company in the Netherlands was selected as control. The results showed that the irrigation amount of the transpiration feedback irrigation system increased by 9.4% compared with the control, the drainage decreased by 18%, and the drainage EC value was stable. Compared with timed irrigation, the amount of irrigation was reduced by 32% and the amount of drainage was reduced by 57% by using the transpiration feedback irrigation system, and more nutrients were absorbed and utilized by tomatoes. There were no significant differences between the fruit yield, plant height, and node number of the tomato by using the transpiration feedback irrigation system and those by using the irrigation system designed by the RIDDER company. Under the condition of 10 years of the design life of irrigation system in 5 000 m² greenhouse, compared with the application of the irrigation system designed by the RIDDER company, the annualized cost of the intelligent irrigation system designed by this study was 20.8% lower than that by using the irrigation system designed by the RIDDER company. The transpiration feedback intelligent irrigation system could meet the requirements of automatic precision irrigation, and if the irrigation control model might adjust according to the substrate characteristic, the system could also be used for automatic precision irrigation of the Rockwool cultivation, the mixed substrate potted cultivation, and other soilless culture. [ABSTRACT FROM AUTHOR]

Using coconut shell and boric acid as raw materials， a new boron-doped coconut shell mesoporous carbon material （B-CSC） was prepared using a simple one-step pyrolysis method for efficient adsorption and removal of tetracycline pollutants in water. The effects of pyrolysis temperature and boron-carbon mass ratio on the adsorption performance under key preparation conditions were systematically studied， and their microstructure and physicochemical properties were characterized using a specific surface area and pore size analyzer （BET）， field emission scanning electron microscopy （SEM）， X-ray photon spectroscopy （XPS）， Raman spectrometer （Raman）， and Zeta potentiometer （Zeta）. The effects of initial pH， different metal cations， and different background water quality conditions on the adsorption effect were systematically investigated. Combined with material characterization and correlation analysis， the enhanced adsorption mechanism was discussed and analyzed in depth. The results showed that one-step pyrolysis could incorporate boron into the surface and crystal lattice of coconut shell charcoal， resulting in a larger specific surface area and pore volume， and the main forms of boron introduced were H 3 BO 3 ， B 2 O 3 ， B， and B 4 C. The adsorption capacity of B-CSC to tetracycline reached 297.65 mg·g -1 ， which was 8.9 times that of the original coconut shell mesoporous carbon （CSC）. At the same time， the adsorption capacity of B-CSC for rhodamine B （RhB）， bisphenol A（BPA）， and methylene blue （MB）， common pollutants in aquatic environments， was as high as 372.65， 255.24， and 147.82 mg·g -1 ， respectively. The adsorption process of B-CSC to tetracycline was dominated by physicochemical interaction， mainly involving liquid film diffusion， surface adsorption， mesoporous and microporous diffusion， and active site adsorption， and H 3 BO 3 was the main adsorption site. The adsorption strengthening mechanism mainly reduced the chemical inertness of the carbon network and enhanced its π-π interaction and hydrogen bonding with tetracycline molecules.

In order to test the perfonnance of bioretention system in treating smface runoff pollutants, three bioretention systems with three kinds of mass ratios of planting medias were designed and constructed outdoors in Zhenjiang City, then mesocosms of bioretention system were implemented by river water to simulate smface runoff. The results showed that there was no significant difference among the three bioretention systems in terms of pollutant reduction. The concentrations of total phosphorus ( TP) and ammonia nitrogen ( NH4+ -N) in the effluent of the bioretention systems were relatively stable in one test, and the concentration of total nitrogen (TN) was relatively stable or fluctuated greatly. The concentration of chemical oxygen demand (COD) basically decreased and then increased, while the concentration of total suspended solids ( TSS) decreased and remained the same. In a total of 12 tests, environmental quality standards for surface water of TP, NH4+ -N, TN, COD were respectively II or llI, II, exceeds V and II - N. The average reduction rates of TP, NH4+ -N, TN, COD and TSS were 81 % - 96%, 78% -99%, -146% -98%, - 27% - 75% and 14% - 54% . The average reduction rate of NH.t - N increased with the increased of the concentration of inflow. The average concentration reduction rate of TN basically showed a positive and negative alternating trend, which increased with the relative increase from the concentration of the inflow. This study provided a certain reference for the application of bioretention system composed of soil, coconut coir and sand in the construction of the sponge cities. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)