scholarly journals Design and performance of urban sponges in red soil: improvement of physical and chemical properties

Author(s):  
Yunpeng Jing ◽  
Jian Li ◽  
Yimin Mei ◽  
Xiao Liu ◽  
Xuelan Yu ◽  
...  

Abstract This study investigated the physical and chemical properties of a single or combination of permeable materials which can be used as fillers in the Sponge City program in China. Four types of fillers, perlite, coral sand, vermiculite and ceramsite, were selected from six alternative fillers by an analytic hierarchy process. The optimal city sponge, which consists of vermiculite (10 cm), ceramsite (15 cm), perlite (15 cm), coral sand (20 cm) and Canna indica L, was found by the orthogonal experiment (L16(45)). The results of the simulated rainwater experiment of the optimal sponge showed that the permeability coefficient K10, NH3-N, TP and COD removal rate were 1.20 ± 0.23 mm/s, 96.6 ± 0.2%, 36.8 ± 0.07% and 9.6 ± 0.07% respectively. The results suggested that the optimal sponge had an excellent treatment effect on NH3-N in rainwater while ensuring rapid infiltration. It provided a simple, economical and effective method for rainwater treatment and the Sponge City program in the future.

2013 ◽  
Vol 864-867 ◽  
pp. 1319-1322
Author(s):  
Shan Hong Lan ◽  
Rui Chen ◽  
Ping Ma ◽  
Cong Cong Li ◽  
Hui Xia Lan

The method of activated sludge has been widely used in the process of sewage treatment for its high-efficiency and low-consumption. The effect of Fe3+ on microbial growth and physical and chemical properties of activated sludge were studied to obtain relevant parameters for the running of activated sludge system in this paper. Firstly, study on the effect of Fe3+ on microbial growth was carried out. The experiment results showed that the lag phase of microbial growth was obviously reduced with the presence of Fe3+, obtaining advancing into the logarithmic phase. Whats more, the value of OD600 reached to the maximum of 0.615 at 12h when the concentration of Fe3+ was 30mg/L. Secondly, the effects of Fe3+ on the wastewater treatment and that of the performance index include SVI and MLSS were studied. The results indicated that SVI decreased with increasing the dosages of Fe3+,while MLSS and removal rate of COD obviously increased which reach to the maximum of 88.21% when the concentration of Fe3+ was 30mg/L.


2020 ◽  
Vol 10 (9) ◽  
pp. 3174
Author(s):  
Meng-Chia Weng ◽  
Chiou-Liang Lin ◽  
Cheng-Hsi Lee

The heat treatment of oil-contaminated sites is widely carried out for the purposes of remediation. However, heat treatment changes the physical and chemical properties of soil. Before the soil can be reused as a construction material in civil engineering, such as in backfill or road base materials, the changes to its physical properties must be understood. Therefore, this study investigates the changes in the physical and chemical properties of oil-contaminated soil after heat treatment. In this investigation, experimental samples of soil with added oil from a refinery plant are used to investigate the removal rate of total petroleum hydrocarbons (TPHs) by thermal desorption and incineration. The physical properties of the soil, including water permeability and mechanical properties, are compared before and after heat treatment. The results of this study are as follows. (1) Particle size analysis reveals that heat treatment makes soil particles finer. (2) In the burning reduction test, heat treatment at 900 °C removes more than 90% of THP. (3) In the direct shear test, the friction angle (ϕ) increases with the removal rate. (4) In the hydraulic test, as the removal rate increases, the permeability coefficient increases after heat treatment.


2010 ◽  
Vol 129-131 ◽  
pp. 794-798 ◽  
Author(s):  
Hui Lai Mu ◽  
Sheng Li Wang ◽  
Zhen Xia Li ◽  
Wen Zhong Xu ◽  
Xia Xiang

Chemical mechanical polishing (CMP) has become an essential technique in advanced ULSI process. The mechanism of Ta CMP is discussed in this paper. According to the physical and chemical properties of Ta, the alkaline polishing slurry and proper process parameters for Ta CMP are prepared. The paper optimized four key parameters-abrasive concentration, organic alkali, oxidant and surfactant concentration, obtained the comprehensive optimized slurry used in evaluating the removal rate using Taguchi method. The results indicate that: abrasive concentration is 10%, the organic alkali concentration is 15ml/L, the oxidant concentration is 10ml/L and the surfactant concentration is 10ml/L, higher removal rate can be obtained.


2014 ◽  
Vol 654 ◽  
pp. 20-23
Author(s):  
Hui Xue Bao ◽  
Qiang Liu ◽  
Xiao Qin Zhou

Sapphire (Al2O3 crystal) is a hard and inert material with good mechanical, optical, physical and chemical properties that plays important roles in optics and electronics. The surface quality is the key element of sapphire components especially in optical field. This paper mainly introduces four methods of ultra-precision polishing, researches based on polishing theories and slurry. It can be a conclusion that traditional polishing methods can improve material removal rate assisted by ultrasonic.


1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.


2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.


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