scholarly journals A Review of the Commercial Uses of Sulphate Minerals from the Titanium Dioxide Pigment Industry: The Case of Huelva (Spain)

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 575
Author(s):  
Manuel Jesús Gázquez ◽  
Manuel Contreras ◽  
Silvia María Pérez-Moreno ◽  
Jose Luis Guerrero ◽  
Melquiades Casas-Ruiz ◽  
...  

This study was focused on the historical evolution of the waste management policy carried out by the Spanish industry devoted to titanium dioxide pigments manufacturing for minimising its environmental impact. This challenge was achieved by modifying the original chemical process and converting the originally dissolved sulphate and sulphuric acid present in the final streams of the factory into sulphate minerals (melanterite FeSO4·7H2O, szomolnokite FeSO4·H2O, and gypsum CaSO4·2H2O). These by-products were physicochemically, mineralogically and radiologically characterised in order to gain basic information for its subsequent commercial use. Some of the uses summarised in this study for both ferrous sulphates are as a supplier of iron to prevent chlorosis, animal food, manufacture of cement (to reduce Cr VI), primary flocculants for ferrous sulphates, magnetite nanoparticle and nano-Fe2O3 formation, production of magnetite concentrate, remediation of polluted soils with metals, and treatment of wastewaters. Red gypsum was analysed as a substitute for natural gypsum in the manufacture of cement, construction materials, inhibitor in soil erosion, and the immobilisation of heavy metals in agricultural soils and carbonation processes.

2021 ◽  
Vol 13 (6) ◽  
pp. 3517
Author(s):  
Lien Thi Kim Trinh ◽  
Allen H. Hu ◽  
Song Toan Pham Phu

Municipal solid waste management is an environmental issue that has received considerable attention from researchers and environmental managers for decades. Supporting the management programs entail policies and regulations related to municipal solid waste. In developed countries, the implementation of environmental policies plays an important role and has a substantial impact on the effectiveness of solid waste management. However, in many developing countries such as Vietnam, the situation and effectiveness of the policy implementation have not been studied extensively. This investigation is conducted to ascertain the situation, limitations, and challenges in implementing solid waste management policy in Vietnam. Then, solutions for the problems and improvements for implementation efficiency are presented. This work used online questionnaires to survey environmental managers in different localities and applied qualitative research method to analyze data. The results show that not all national policies on solid waste management are implemented in all localities. Waste separation is also the foremost concern in municipal waste management in most localities of Vietnam. Most of the localities claimed that the unrealistic nature and difficult implementation of the policies and the lack of needed resources are the main limitations and challenges in Vietnam. Survey results also revealed that different localities in Vietnam have different solutions to increase policy implementation efficiency. Besides, the study also found similarities in the implementation of policies in solid waste management between Vietnam and some other countries and also gathered some valuable lessons for the improvement strategy. Finally, the implementation of an effective domestic solid waste management policy is an important platform for improving environmental quality and ensuring the sustainable development of the nation and mankind.


2021 ◽  
Vol 13 (5) ◽  
pp. 2756
Author(s):  
Federica Vitale ◽  
Maurizio Nicolella

Because the production of aggregates for mortar and concrete is no longer sustainable, many attempts have been made to replace natural aggregates (NA) with recycled aggregates (RA) sourced from factories, recycling centers, and human activities such as construction and demolition works (C&D). This article reviews papers concerning mortars with fine RA from C&D debris, and from the by-products of the manufacturing and recycling processes of building materials. A four-step methodology based on searching, screening, clustering, and summarizing was proposed. The clustering variables were the type of aggregate, mix design parameters, tested properties, patents, and availability on the market. The number and the type of the clustering variables of each paper were analysed and compared. The results showed that the mortars were mainly characterized through their physical and mechanical properties, whereas few durability and thermal analyses were carried out. Moreover, few fine RA were sourced from the production waste of construction materials. Finally, there were no patents or products available on the market. The outcomes presented in this paper underlined the research trends that are useful to improve the knowledge on the suitability of fine RA from building-related processes in mortars.


2021 ◽  
Vol 291 ◽  
pp. 112584
Author(s):  
Martin Rosecký ◽  
Radovan Šomplák ◽  
Jan Slavík ◽  
Jiří Kalina ◽  
Gabriela Bulková ◽  
...  

2021 ◽  
Vol 24 (1) ◽  
pp. 90-119
Author(s):  
Rosie Syme

An effective waste management system is, and has always been, essential infrastructure, particularly given the potential for waste to adversely impact the surrounding environment. In recent decades, however, there has been growing awareness of the scale, breadth and immediacy of those adverse impacts, and of the unsustainability of the enormous (and increasing) amount of waste society generates. Governments around the world have mobilised and there has been a widespread shift towards policies promoting circular economies, waste minimisation and maximised resource efficiency. Singapore is a case in point; despite having a traditionally high waste output and a waste management system dependent on waste incineration as the primary means of disposal, Singapore has committed to a zero waste future. This article presents a review of domestic waste management policy and law in Singapore. Several gaps in the legal framework are identified and considered against the broader context, leading to the conclusion that there is a material environmental vulnerability in the legal framework that should be redressed in order to entrench environmental protections and to align the law with Singapore's policy ambitions. Notwithstanding this deficiency, it is hard not to be optimistic about the future of domestic waste management in Singapore, as the government has made an ambitious policy commitment and appears to be pursuing it with vigour.


2019 ◽  
pp. 658-687 ◽  
Author(s):  
R. V. Ralegaonkar ◽  
M. V. Madurwar ◽  
V. V. Sakhare

Due to ever increasing demand for the conventional construction materials as well as an increase in agro-industrial by-products it is essential to reuse these materials. As a smart city solution this chapter briefs an overview for the application of alternate raw materials as a principal source for the development of sustainable construction materials. The potential application of the discussed raw materials is elaborated as cementitious material, the aggregates as well as alternative reinforcement material. To understand the process of application, sustainable masonry product development is discussed in detail. In order to evaluate the feasibility of the raw material, the necessary physico-chemical test evaluation methods are also briefed. The developed end product performance evaluation is also discussed by desired tests as recommended by standards. The chapter concludes with a positive note that reuse of agro-industrial by-products is a feasible solution for the smart city development.


2020 ◽  
Vol 148 ◽  
pp. 05005
Author(s):  
I Made Wahyu Widyarsana ◽  
Enri Damanhuri ◽  
Nida Ulhusna ◽  
Elprida Agustina

Bali Province is an island of high tourist activity surrounded by the sea. Without a proper mainland waste management, waste problem will impact the aquatic environment. River and beach are waterways that become an important role in the waste flow that will end to the sea. Identification of waste in rivers and beaches is needed to determine the stream waste management policy. Measurements were made by adopting the NOAA (National Oceanic and Atmospheric Administration) method on 4 rivers and 4 beaches. Measurement of waste generation and composition represents the watershed and population density classification groups. The peak hour for the waste streams at 11.00-14.00 WITA (GMT+8). The dominant waste is organic waste (59.10% WW) and hazardous waste (17.12%WW). From the waste measurement on the beach, the waste density is around 0.087 tonnes/m3 and the composition of waste is dominated by plastic waste, paper waste, and textile waste. The average waste density in beach is around 0.007 kg/m2 or 0.53 items/m2. Yeh Gangga Beach is the dirtiest with 0.64 items waste/m2 and Lepang Beach is the cleanest beach with 0.27 items/m2.


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