Analysis of Hydraulic Characteristics and Treatment Efficiency by Filter Media Composition During Backwashing of Filtration-Type Non-Point Pollution Facilities

In this study, the hydraulic characteristics and pollutant treatment efficiency during backwashing were analyzed through laboratory-scale hydraulic model experiments for filtration-type non-point pollution reduction facilities. The filter media used in the experiment were analyzed by calculating the change in head loss for single or complex arrangements of wood chips (WC), sand (SA), and bottom ash (BA). These are commonly used to improve the adsorption mechanism in non-point pollution reduction facilities, from which the pollutant treatment efficiency was derived. The SS treatment efficiency experiments for each filter media layer were conducted with SA+WC (WC 0.3 m in the upper layer, SA 0.3 m in the lower layer) and SA+BA (SA 0.3 m in the upper layer, BA 0.3 m in the lower layer), and the removal efficiency was greater than 80%, indicating good efficiency. In the case of SA+BA, analysis showed a high removal efficiency of 87.4% at a linear velocity of 20 m/hr.

The role of fine management techniques in association between agricultural pollution and farmer income: The case of fruit industry

Abstract text is required. Whilst the agriculture enjoys booming development, it is facing increasingly serious environmental pressures. With the growth of fruit planting scale, the inorganic minerals elements are one of the main sources of non-point pollution. How to achieve the sustainable production of agriculture is an issue that needs urgent attention in the current rural development. In this paper, based on the micro-production data of peach farmers in eighteen prefecture-level provinces, we introduce fine management techniques into the production function to analyze the effects of different techniques and further explore the influence of fine management techniques on the fertilizer efficiency. Findings show that with no changes in the degree of fine management techniques investment, the increase of chemical fertilizers and pesticides not only made little contribution to increase in profit, but also resulted in excessive investment of fertilizers that worsens the environment. Notably, the fine management techniques exerting positive effects on the application efficiency of minerals elements could be an efficient and sustainable way to ease the conflict between environment and profit. However, those techniques are rarely used in practices due to the lack of economic incentives. A brief review of main measures, such as market information timely-updating，agricultural product branding, and socialized services, is offered.

Nitrogen Fertilization. A Review of the Risks Associated with the Inefficiency of Its Use and Policy Responses

Nitrogen (N) is a key input to food production. Nearly half of N fertilizer input is not used by crops and is lost into the environment via emission of gases or by polluting water bodies. It is essential to achieve production levels, which enable global food security, without compromising environmental security. The N pollution level expected by 2050 is projected to be 150% higher than in 2010, with the agricultural sector accounting for 60% of this increase. In this paper, we review the status of the pollution from N fertilizers worldwide and make recommendations to address the situation. The analysis reviews the relationship between N fertilizer use, N use efficiency, no-point pollution, the role of farmer management practices, and policy approaches to address diffuse pollution caused by N fertilization. Several studies show a lack of information as one of the main hurdles to achieve changes in habits. The objective of this study is to highlight the gravity of the current global non-point pollution as well as the need for a communication effort to make farmers aware of the relationship between their activity and N pollution and, therefore, the importance of their fertilizer management practices.

Use of Multivariate Statistical Techniques to Study Spatial Variability and Sources Apportionment of Pollution in Rivers Flowing into the Laizhou Bay in Dongying District

Spatial variability and source apportionment of river pollution flowing into the Bohai Sea are of great significance to the pollution liability and development of control strategies to reduce the terrestrial discharge of pollution in the ocean. In this study, ten water quality variables from 14 monitoring sites in rivers flowing into Laizhou Bay were obtained to investigate the spatial variation and pollution sources in Dongying District from 2018–2019. The survey area was divided into a low pollution (LP) zone and a high pollution (HP) zone by cluster analysis based on ten indicators. Principle component analysis/factor analysis with a geographic information system was performed to identify the four main pollution sources in the survey area. Compared with the positive matrix factorization model, the absolute principal component score-multiple linear regression (APCS-MLR) model was more appropriate for the source apportionment of pollution in the surface water of Dongying District. The point source pollution of domestic sewage (23.6%) was the most crucial pollution source of water in the LP zone, followed by non-point pollution from agricultural activity (16.4%). The contribution rate in the HP zone analyzed by the APCS-MLR model followed a decreasing order: point source pollution from domestic sewage (28.5%) > non-point pollution source of overland runoff (14.8%) > point source pollution of hybrid wastewater (12.4%) > point source pollution from industries sewage (10.6%). Therefore, the spatial distribution and sources of pollution in the investigated area should be considered while developing control measures to reduce the discharge of pollution to Laizhou Bay.