The study involves the study of Nalagarh watershed in Himachal as a topographically delineated hydro-geological entity which is allowing the entire surface runoff of its sub-watersheds to channelize through defined streams and drainage network to certain points in the watershed. Geomorphic analysis of Nalagarh watershed has enabled the study of qualitative and quantitative parameters of the watershed for efficient utilization and optimizing the management of its surface and groundwater resources. As Nalagarh valley has recently witnessed the highest industrial growth in the district and State of Himachal Pradesh, the study becomes all the more impertinent. The watershed has been delineated into 13 micro watersheds, based on the geomorphic analysis. To use the surplus monsoon runoff, a detailed study has been carried out for the computation of utilizable runoff and the number of structures that can be planned for its utilization. To effectively plan the rainwater harvesting structures, the morphometric analysis has been done.

Rapid depletion of fossil fuels and escalating crude oil prices led the researchers to ascertain alternative feedstock as a substitute for mineral diesel. Biodiesel produced from non-edible sources was one among them. In the present investigation, palm stearin wax, a residue of palm oil extraction was used as a value-added feedstock for the production of biodiesel. Palm stearin biodiesel (PSBD) was derived from this feedstock using single stage transesterification process involving methanol and sodium hydroxide as a catalyst. PSBD was blended with mineral diesel at 20% (D80PSBD20) and 50% (D50PSBD50) in volume basis. The effect of variable compression ratios on the performance and emission phenomena of direct injection CI engine was analysed for test fuel blends. The tests were carried out for compression ratios 17:1, 17.5:1 and 18:1. Among all the fuel blends, D80PSBD20 blend showcased better performance characteristics along with reduced exhaust emissions at compression ratio of 18:1.

Visible light-driven photocatalytic oxidation technology has shown great potential for effective removal of organic pollutants from water and mitigation of energy crises at the same time. The highly effective and economic b-Fe2O3/BiOCl0.875Br0.125 photocatalyst was prepared by a facile hybrid compositing method with b-Fe2O3 and BiOCl0.875Br0.125 to overcome relatively high material cost and limited catalytic efficiency. Characterization techniques, such as XRD, SEM and XPS were used to study the purity and crystallization characteristics of the as-prepared photocatalyst. Furthermore, taking rhodamine b (RhB) as a simulated organic pollutant, the photocatalytic property of b-Fe2O3/BiOCl0.875Br0.125 with different Bi content was further evaluated by static catalytic degradation test under visible-light. The results indicated that the photocatalytic efficiency of the novel composites increases with the improvement of Bi content. Additionally, in comparison to equal mass of pure phase BiOCl0.875Br0.125, when the Bi content reached to 30%, a comparable and even better photocatalysis performance was achieved by the as-prepared b-Fe2O3/BiOCl0.875Br0.125. The hybrid b-Fe2O3/BiOCl0.875Br0.125 has a potential cost advantage in practical water treatment, and provide an attractive method for fabricating efficient visiblelight- driven photocatalysts.

The occurrence of caffeine residue in Malaysian waters was successfully studied. The micropollutant abundance was recorded for three selected main rivers namely Terengganu, Ibai and Setiu which are located in Terengganu, Peninsular Malaysia. Surface water samples were taken twice in September and November 2018 from 15 sampling stations. Caffeine residue was determined using the solid phase extraction technique followed by a final analysis using a high performance liquid chromatography-UV detector. Measured concentration levels ranged from 384 to 426 ng/L for both datasets obtained from the two sampling surveys. The ecological risk assessment was calculated to be at low risk ranging from RQ 0.075 to 0.085, while the risk quotients (RQ) of human health risk was recorded below than 0.20 for three life-stage categories. The MaxRI values fall under class II which means that there is a risk of sublethal effects to aquatic organisms.

Agriculture is located at the crossing point between ecosystems and society, where changes in the global environmental conditions affect agricultural activities. The total agricultural area in Abu Dhabi Emirate in 2017 was 749,868 donums. This study had two main objectives; first, to understand how agricultural and livestock production has changed and how these changes are relevant to socioeconomic statuses; second, to assess climate change’s impact on agricultural and livestock production through groundwater characteristics. We distributed and collected 301 surveys throughout the three main regions in the Abu Dhabi Emirate (Abu Dhabi City, Al-Ain City, and Al Dhafrah). The results indicated that approximately 68% of the respondents in Al-Ain agreed that it is currently much easier and more profitable to manage a farm than it was 20 years ago. Further, 39% of the farmers agreed that both product quality and quantity have improved over the past 20 years. About 51% of Emirati nationals agreed that production has changed over time. The farmers aged between 51-60 years also agreed that there has been a change in production over time. Half of the farm owners agreed that production has changed, while a majority of the workers provided neutral responses on this topic. While a number of both owners and workers agreed that both production and income levels changed, more respondents disagreed than agreed that these changes had occurred. Finally, the farmers aged between 51-60 years agreed more that the groundwater levels and quality had changed over the past 20 years.

Based on one-year monitoring about the different trophic status freshwater regions of Lake Taihu, the temporal-spatial distribution and occurrence characteristics of nitrogen in the water, porewater, and sediments and their correlation with main aquatic environmental factors were analysed. The results showed that the concentrations of TN in overlying water and sediment ranged from 0.22 to 7.74 mg/L and 551.5 to 1542.8 mg/kg, respectively. The concentrations of NO3-N in overlying water, sediment, and porewater ranged from 0.04 to 3.86 mg/L, 14.3 to 42.5 mg/kg, and 0.01 to 0.72 mg/L, respectively. The concentrations of NH4 -N in overlying water, sediment, and porewater ranged from 0.03 to 0.25 mg/L, 17.7 to 78.2 mg/kg, and 0.41 to 7.03 mg/L, respectively. NH4 -N in overlying water had no significant spatial-temporal variation and the annual mean of NH4 -N in sediments was highest in Meiliang Bay. The annual mean of TN and NO3-N in overlying water and sediments was highest in Western Taihu Lake. The spatial and temporal distribution characteristics of NH4 -N and NO3-N in porewater were roughly consistent with those in sediments. Nitrogen in the sediment occurs in the form of organic nitrogen. Nitrogen in the overlying water was principally of NO3-N in Meiliang Bay and Gonghu Bay, and was principally of organic nitrogen in Xukou Bay. In the Western Taihu Lake, nitrogen in the overlying water was principally of NO3-N in summer and fall, and organic nitrogen in spring and winter. The results suggest that the type of organic matter in sediments was an important factor affecting the nitrogen occurrence characteristics and trophic status in aquatic environment. The correlation analysis showed that TN and NO3-N in overlying water was positively correlated with various forms of nitrogen in sediments, indicating that there was a strong exchange of nitrogen nutrients between water and sediments.

Recently substitution of fossil fuel-based polymer by natural polymer sources has been studied. Cellulose acetate that can be produced from the cellulose of biomass waste is an environmentally friendly and important polymer with many applications. This study was undertaken to determine the most suitable and effective method in the cellulose acetate (CA) production. Moreover, the role of catalyst and usefulness of trichloroacetate and I2 catalyst has been studied. As many as 12 methods of acetylation for CA synthesis has been carried out, and the results have been compared. The peak height ratio of infrared (IR) spectra of acetyl groups was studied to determine the formation of CA. The result showed that the activation step resulted in higher IR spectra peak than the direct synthesis method. An important result of this study was shown when trichloroacetate catalyst combined with H2SO4 resulted in significantly higher IR spectra than the conventional method. Interestingly, I2 catalyst resulted in better IR spectra peak than H2SO4 did, even the activation step was not performed. It showed that the addition of trichloroacetate and I2 in the CA synthesis with acetic anhydride as an acetylating agent was better than conventional CA acetylation method. Furthermore, I2 catalyst showed the best result among other methods and will be the promising pathway to produce CA. Scanning electron microscopy (SEM) analysis showed that the diameter of cellulose fibre was decreased and fracture surface occurred after the synthesis reaction.

Given the increase in energy consumption and the advancement of urbanization, the expected level for the prevention and control of air pollution has not been achieved, and urban air quality has deteriorated significantly. Environmental air ecological compensation has become an important method to control air pollution to realize sustainable economic and societal development. The object, method, and standard for compensation were discussed based on the case study of the environmental air ecological compensation mechanism in the Hubei Province of China. Results show that the compensation mechanism solves the negative externality of the environment caused by the fuzzy air property rights to a certain extent. Besides, the mechanism addresses the dilemma caused by the fragmented management of the local government to the collective action and promotes the transformation from the traditional pollution control mode of the regulated enterprises to the governance mode to strengthen government regulation.

The purpose of the study is to estimate the operating cost of the electrokinetic methods in the removal of toxic metals (TMs) from granite mine tailing soil with the help of the proposed cost estimation models. The conventional electrokinetic technologies have not considered the cost estimation in the removal of TMs from polluted soils. In this study, we incorporated the chelates such as citric acid and ethylenediaminetetraacetic acid (EDTA) enhanced electrokinetic soil remediation process followed by a cost estimation of the processes. Our study proposed the cost estimation models to determine the operating cost of the conventional and enhanced electrokinetic treatment processes, specifically for the removal of six TMs such as chromium (Cr), cobalt (Co), copper (Cu), nickel (Ni), zinc (Zn) and manganese (Mn) from granite mine tailing soil. We investigated the chelating enhanced electrokinetic removal of TMs about six times more than the conventional process for 20 days of operation. Furthermore, we estimated that the operating cost of the conventional and enhanced electrokinetic processes was about US$ 110 to US$ 508 per cubic meter of treated soil. The total operating cost was about US$ 110 to US$ 1006 per cubic meter of treated soil including enhancers cost. We believe the chelating enhanced electrokinetic treatment of soil was more effective than conventional treatment for removal of TMs from contaminated soil.

This paper builds a factor decomposition model of methane emissions from livestock from the three dimensions of technology, economy, and population, by using the panel data covering 31 provincial regions in China during 2003-2016, and aims to reveal the macroscopic causes of methane emissions from livestock. The research shows that technical, economic and population factors of methane emissions from livestock have diminishing marginal contribution. The methane emissions from intestinal fermentation are mainly restricted by livestock’s physiological structure. Following increase or decrease of livestock feeding quantity, it changes with a relatively stable parameter and has little controllability. Methane emissions from faecal management are limited little by livestock’s physiological structure and it is largely controllable. The government should increase technical input to reduce methane emission factors of livestock, deal with livestock manure through resource utilization, and reduce raising scale by using a certain market mechanism in due course.