Desorption of crystal violet from alkali-treated agricultural material waste: an experimental study, kinetic, equilibrium and thermodynamic modeling

Purpose This paper aims to focus on studying the batch desorption of adsorbed crystal violet (CV) from date stones (Phoenix dactylifera), untreated (UDS) and treated using NaOH (TDS). Design/methodology/approach The process variables such as different desorbing agents, volume and concentration of the desorbing agent, contact time, dye concentration before adsorption and temperature affecting CV desorption from CV-loaded untreated date stones (CV@UDS) and treated adsorbent (CV@TDS) were optimized. The UDS and TDS were regenerated using 0.6 m HCl as eluent. Findings The HCl solution was an excellent eluent for the CV desorption from CV@UDS (96.45%) and CV@TDS (98.11%). The second-order model and the Langmuir model well exemplified experimental data with maximum desorption capacities were 63.29 mg g−1 for the CV@UDS and 243.90 mg g−1 for the CV@TDS. The calculated thermodynamic showed that the CV desorption was spontaneous, endothermic and physical. Good regeneration and reusability of UDS and TDS for the CV removal for four consecutive adsorption–desorption cycles. Practical implications This study provided a good example of reusing UDS and TDS with NaOH for fast removal of a toxic organic pollutant, CV from the wastewaters. Originality/value The use of UDS and TDS with NaOH for the first time for desorption study and their reusability to removing CV from their aqueous solutions.

The threshold effect test of human capital on the growth of agricultural green total factor productivity: Evidence from China

This paper constructs a threshold regression model to empirically test the non-linear relationship between rural human capital and agricultural green total factor productivity (AGTFP) with provincial panel data during 1993–2018. The results show that there is a significant double threshold effect between rural human capital and AGTFP under different levels of agricultural material capital (AF)and agricultural economic development (AGDP). When AF and AGDP are at different levels, the relationship between rural human capital and AGTFP presents an inverse N-type trend or an inverted U-type trend. The nonlinear relationship between rural human capital and AGTFP has been verified. It is necessary to attach importance to the promotion of agricultural human capital to the growth of AGTFP. It is suggested to strengthen education on environmental protection and green production technology training for farmers, and urge them to widely adopt the production mode of mitigating climate warming. In addition, it is important to ensure the coordinated development of AF and rural human capital while enhancing the input of AF.

Selecting the Optimal Green Agricultural Products Supplier: A Novel Approach Based on GBWM and PROMETHEE II

Due to the uncertainty of natural factors and a larger global population, the work of supplying sustainable agricultural materials, especially green agricultural products, faces enormous challenges. How to effectively evaluate and select the most desirable green agricultural material supplier is an urgent issue for both agribusiness and government. In this paper, an integrated q-rung orthopair fuzzy (q-ROF) group best–worst method (GBWM) and the PROMETHEE II was introduced to availably solve such issue. Firstly, by taking similarity degree into account to solve incomplete weight information, a novel technique was constructed to determine the experts’ weight reasonably under the q-ROF context. Secondly, to improve consistency for group decision making and obtain a highly reliable selection result, the GBWM was used to derive criteria weights. Then, based on the proposed generalized p-norm knowledge-based score function, the PROMETHEE II was further improved to rank the feasible alternatives. After that, a representative case under the background of green agricultural material supplier selection was investigated in depth. Finally, the detailed comparative technique was conducted to verify the validity and superiority of the improved method.

Geographical Indications and Designations of Origin linked Agricultural Products: Current Statistics from Turkey

Geographical indications and designation of origins is an industrial property right describing a product originated from any region or attributable to any region due to its quality, reputation or other characteristics. Particularly, the geographical indications (GI) provide information about the raw material or final products’ geographical roots to consumers and characterize the degree of its quality. Two types of GI were defined: Protected Designations of Origin (PDO) and Protected Geographical Indication (PGI). On the other hand, the products that cannot be registered as a designation of origin or geographical indication could be registered as Traditional Speciality Guaranteed (TSG) products specialty guaranteed if it can be proven that the product is on the traditional market for at least 30 years. The main goal of this research is to examine Turkey’s current status about labelled geographic agricultural material with a comparative statistic overview.

A Study of Carbon Coated Flat Stick Bamboo Microwave Absorber Performance

Electromagnetic radiation can be prevented by using microwave absorber. Microwave absorbers are applied in an anechoic chamber for the electromagnetic compatibility (EMC) and electromagnetic interference (EMI) evaluation on its wall, ceiling, and floor. The purpose of this research is to develop a carbon-coated flat shape of biomass absorbers using an agricultural material. The main material used in constructing the flat absorber is natural bamboo. The flat shaped absorber is selected as it able to meet the specified industry standard and can be used appropriately in the microwave frequency range. Carbon coated cylindrical bamboos with different radiuses have been used for this study. Studies were conducted on two different sizes of the radius that is 0.2 cm for Design 1 and 1 cm for Design 2. The ranges of frequencies are set in the range from 1 GHz to 12 GHz. The result of the microwave absorber is analyzed for its absorption performance. The generated result from the performance shows that the carbon-coated flat stick bamboo microwave absorber operates the best in Design 2 with 45.7% of absorption performance compared with Design 1. The overall results in different angles for both designs are analyzed and compared.

Analysis of the Agricultural Economy and Agricultural Pollution Using the Decoupling Index in Chengdu, China

The development of the agricultural economy has brought the agricultural pollution, and agricultural pollution has restrained the growth of the agricultural economy and endangered public health. Since the Economic Reform opened up, China has promulgated many policies that have benefited farmers, developed the agricultural economy, and improved agricultural material levels. However, the growth in the agricultural economy has also resulted in significant environmental pollution from pesticides, agricultural fertilizers and agricultural plastic film. Agricultural pollution can affect public health, therefore it is necessary to study the relationship between agricultural economy and agricultural pollution. In this paper, the relationship between the agricultural economy and agricultural pollution is studied by using decoupling index method, taking Chengdu, Sichuan Province, China as an example, and verified by the data of 2008–2017 years of Chengdu. It was found that the decoupling index for pesticide use and per capita gross agricultural production showed “strong decoupling” ideal states in six years. From 2009–2017, the value of it increased from 0.065743–1.597385, and its decoupling state gradually transited to stable strong decoupling. The chemical fertilizer use was found to have a “strong decoupling” ideal state in five years. The value of it decreased from 1.028854–(−0.512702), while its state gradually changed to strong decoupling. However, agricultural plastic film only has one “strong decoupling” state with its value of decoupling index changed from −0.380824–(−0.250250). The increased use of plastic film has resulted in increased agricultural pollution. The research results show that growing with the development of Chengdu’s agricultural economy, the use of pesticides and fertilizers has been decreasing. Chengdu’s agricultural economy and agricultural pollution were found to have a healthy and coordinated development. The development of agricultural economy has not caused much damage to the agricultural environment. In addition, with the decline of agricultural pollution, public health problems will also be reduced.