Sugar Mill Research Articles

O Engenho de açúcar: André João Antonil and the Anatomy of the Seventeenth-Century Brazilian Slave Plantation

Jesuit João André Antonil’s Cultura e Opulência do Brasil is perhaps the first comprehensive treatise on slave plantation agriculture in the Americas. However, it is neither a manual nor an economic analysis. Rather, it is a moral and ethical guide for the administration of a sugar mill. This article examines the concepts, categories of thought, structures of meaning, and interpretive strategies through which Antonil comprehends the process of commodity production for the world market on the slave engenho. Antonil’s conceptual horizon was constrained by the Jesuit synthesis of Aristotelean thought and post-Tridentine Christian doctrine and the conception of the Last Judgement as the end of historical time. Consequently, he could not conceptualize the modernity of Atlantic slavery, the world market, and the plantation as a new temporality. Instead, he analyzes the engenho through the Aristotelean concept of oikos or household. The categories of thought and action through which Antonil comprehends the slave plantation and world market reveal the contradictory relation between slave production and the world market in the Iberian Atlantic.

Turning the Wheel through the Ages

Methods for reliably generating alternating current via placing metal coils in a rotating magnetic field were discovered by two individuals almost simultaneously: Italian engineer and physicist, Galileo Ferraris, and Austrian-American engineer, Nikola Tesla. While Tesla attained the patent for the AC-generator, Ferraris, who published the discovery a few months prior, is credited with having paved the way for the modern-day alternator, now used ubiquitously.The origins of rotational energy conversion can be traced back to sugar plantations in the 1600s. At that time, the milling process was initially sustained through slave-driven turning of a wheel, which was geared to large wooden rollers that would squeeze sugar cane. The Caribbean and South American variant of this system was known as a trapiche, which employed three geared rollers. Over time, slaves were replaced with oxen and horses, which were eventually supplanted by water wheels and finally by steam engines. The water wheels implemented for sugar milling ultimately paved the path for creating electrical currents. Water turbines for hydroelectric power subsequently took off. Principles of steam engine operation were adapted for electrical power as well, ultimately culminating in the use of nuclear plants to generate “wheel” turning for electricity.Electricity and magnetism, as well as interactions between them, are frequently discussed in introductory undergraduate physics. However, practical applications of these principles are often omitted from lectures. If taught under an experiential environment, these concepts can be introduced at even the middle school level, taught by first year college students taking basic college physics - a synergistic learning environment. With this in mind, we developed a middle school kit consisting of simple 3D-printed components, recycled DVDs and four bearings for support of 4 mm nail shafts. Enameled wire (30 AWG) is used to prepare the wire-wound coils. A large rubber band is used as the pulley-belt. The above represents the generator component. The power use component is assembled on an accompanying bread board. Power processing is demonstrated using diodes for rectification to DC. The DC power is used to recharge a 3V, 40 mAh lithium-ion coin cell. AC power from the generator can also be directly applied to load resistors. Students will be able to see the effects of varying the load by changes in the time of the free rotation of the generator wheels. Students will experience the charge and discharge of batteries with safe voltages and currents.Middle school students will record data from the generator and conditioning systems and draw conclusions on worksheets that accompany the hardware.

Hybrid data‐driven modeling for accurate prediction of quality parameters in sugarcane milling with fine‐tuning

AbstractThe data‐driven model for predicting sugarcane milling quality parameters is crucial for optimization. Current challenges include real‐time data acquisition and limited labeled data, reducing model accuracy and raising data collection costs. There is an urgent need to utilize unlabeled data to establish data‐driven models for sugarcane milling. This study introduces novel hybrid strategies, namely combining Convolutional Neural Network (CNN) with Kernel Extreme Learning Machine (KELM), utilizing pre‐training and fine‐tuning techniques. These strategies include CNN‐KELM and Transfer Learning CNN‐KELM (TL‐CNN‐KELM). Results demonstrate superior accuracy compared to single algorithms. TL‐CNN‐KELM, leveraging unlabeled data through transfer learning, achieves reductions of 0.007 in mean squared error and 0.005 in mean absolute error for extraction rate predictions. For initial juice sugar content predictions, reductions of 0.027 in mean squared error and 0.012 in mean absolute error are attained. This approach demonstrates enhanced accuracy in predicting quality parameters while maintaining robustness to data size.Practical ApplicationsThis work can reduce the data acquisition cost for quality parameter prediction and accelerate the intellectualization of sugarcane milling. In production practice, there are many process industries similar to sugarcane milling, so the novel algorithms also provide an idea for the quality parameter optimization and prediction of other process industries.

The roles of accounting in the racial organization of work

This paper analyzes the links between accounting, race, and labor control from a critical perspective. For this purpose, a decolonial perspective is adopted. In particular, the colonial matrix of power is used to analyze a case of labor precarization in a sugar mill in the geographic valley of the Cauca River in Colombia. The study assumes that the precarization of individuals/peoples in contexts with a colonial legacy is fundamentally associated to classification/hierarchization processes based on race, knowledge, being, and territory (Quijano, 2000; Walsh, 2008; Segato, 2014). This paper contributes to a better understanding of the role of accounting in labor precarization in environments with a colonial legacy, showing that, unlike previous literature has proposed, accounting exercises multiple roles in the same organizational time and space, with these roles not necessarily being subordinated to whether the geopolitical realities of the Global South or the Global North are analyzed. Considering the case analyzed, when accounting wishes to control the labor of salaried and non-racialized people, it predominantly exercises its constitutive and transformative role in order to make labor more efficient-profitable, while at the same time it can exercise a reproductive and representative role by (re)creating over-exploitation mechanisms on non-salaried and racialized people to maintain an unequal-racist-discriminatory social order.

Flowsheet analysis of bio-derived hydrogen as a surplus product at sugar mills and associated biorefineries from processing residues

The novelty was to investigate the self-sufficient integration of bio-derived H2 production at a sugar mill from lignocellulosic residues that is available at 65 tonne/h, using gasification OR anaerobic-digestion with biogas-reforming (ADR) that may include vinasse generated from an annexed ethanol distillery. Thus, the optimal use of lignocellulosic residues should ensure a steam supply of 120 tonne/h to the sugar mill, while also optimising the production of H2. Overall process economic costs were evaluated with the minimum selling price of H2 (MSPH). Thus, gasification processes may have produced 2566 kg/h of H2 at the lowest cost of 6.9 US$/kg, and ADR may have produced 2067 kg/h of H2 at 7.7 US$/kg from lignocelluloses that underwent steam-explosion. Otherwise, annexing ethanol production could allow an H2 selling price under 5 US$/kg, if ethanol trades above 1.6 US$/kg. Generally, the milling season limited the annual H2 production, and hence the annual economic returns.

Bitter legacy: archaeology of early sugar plantation and slavery in São Tomé

Praia Melão, the largest sugar mill and estate in São Tomé, active from the sixteenth to the nineteenth centuries, is the first archaeological site ever investigated on the island. It embodies the inception of the plantation economic system predicated on the labour of enslaved people and of local resistance.

What Could Reduce the Cost of Sugar? The Case of State-owned Sugar Mills in Bangladesh

Since the early 2000’s trade liberalization, the state-owned sugar mills in Bangladesh have started to lose competitiveness. Before that this industry used to be considered a strategic sector because sugar is an essential food and the industry creates thousands of rural employments. In 2020, the government suspended operation of six out of fifteen mills with the excuse of loss. The closure of six mills has reduced the sugar production and negatively impacted the lives of farmers, workers, and businessmen. The government is considering foreign investment without considering the potential of government investment to revive the industry. Therefore, it is important to re-examine the factors that increased the cost and find out how the state could revive the industry under its ownership. This paper analysed the data of 15 state-owned sugar mills for 14 years (2006-07 to 2019-2020) using mixed method (fixed effect regression and interview) to explain the mechanisms of the cost increase. It found that the recovery rate, price of sugarcane, availability of sugarcane, age of mills, and interest payment are the most important determinants of cost. Modernizing the mills, making sugarcane available through sugarcane price incentives, timely payment to farmers, and diversifying products could contribute to cost reduction. Social Science Review, Vol. 39(3), Dec 2022 Page 133-151

Assessing the efficacy of different formulations of organic granules immobilizing Azotobacter chroococcum and Bacillus subtilis on productivity and yield of wheat (Triticum aestivum L.) at different water regimes

Microbial biofertilizers can be effective alternatives to fulfil plants' nutritional requirements as chemical fertilisers are considered unsustainable and a threat to environmental and health concerns. However, farmers hardly adopt these bioinoculants due to the uncertainty of their effectiveness in field conditions. In this study, we used porous dry organic materials obtained from biodegradable nontoxic agro-waste and process byproducts from agro-based industries which can act as a suitable carriers and protect the microbes during storage, marketing and field application. In this study, we created various formulations for Azotobacter chroococcum and Bacillus subtilis by combination presmud, cow dung manure as the organic matrix and jaggery, molasses, and serous gum as the binder and clay as the stabilizer. Azotobacter chroococcum and Bacillus subtilis increased straw and grain yield in wheat (Triticum aestivum L.) over the unimmobilized biofertilizers and other used matrixes and binders in irrigated as well as water stressed cropping conditions. The immobilized biofertilizers significantly increased soil fertility and nutrient availability compared to the unimmobilized PGPRs. The formulation IBF-VI showed a 35.9 and a 61.21% increase in grain and straw yields, respectively, over unimmobilized PGPRs. Interestingly, the biofertilizers immobilized in the organic matrix have supported similar grain and straw yield recorded for the synthetic chemical fertilizer’s urea and DAP. The performance of selected immobilized biofertilizers was further examined at various water regimes to measure their efficacy in wheat growing under water stress. The studies show that immobilizing microbial biofertilizers in sugar mill waste press mud and molasses for granule production improves the performance of the microbial biofertilizers. These compounds are abundant and inexpensive locally, and small-scale entrepreneurs can supply them on a small scale. The findings provide a new potential for producing and marketing customised effective microbial bio-fertiliser formulations in rural areas using small industrial setups.

Novel modelling for a steam boiler under fast load dynamics with implications to control

This paper describes a new nonlinear dynamic model for a natural circulation boiler. The model is based on physical principles, i.e. mass, energy and momentum balances. A systematic approach is followed leading to new insights into the physics of drum water level and downcomer mass flow. The model captures fast dynamic responses that are necessary to describe the operation of a boiler under highly variable load conditions. New features of the model include (i) a multi-compartment model for the risers, (ii) a new model for drum water level, and (iii) a new dynamic model for the flow of water in the downcomers. Implications of the model for control system design are explored in detail. Finally, the suggested improvements are validated in a sugar mill boiler (50 [MW] Babcock & Wilcox water-tube boiler).

Model construction and optimization for raising the concentration of industrial bioethanol production by using a data-driven ANN model

This work aims to model and predict the bioethanol produced from a conventional fermentation process. An industrial dataset was obtained from a sugar mill in India. These datasets comprised a total of 1300 experimental values acquired from a total 100 days of production of the sugar mill in the year 2021. Using this data, a framework based on deep learning Artificial Neural Network (ANN) technique model was developed and validated with the test data. Specifically, the normalized dataset was passed through an ANN model consisting of one input layer, two hidden layers and one output layer, and the percent model error calculated by using average absolute deviation metric and was found to be 4.48 and 1.99% for training and testing data, respectively. The optimization of the process variables was performed for the first time using a data synthesis technique in which the normalized dataset was first synthesized and then passed through an ANN model to get an optimized input variable set for an increase in bioethanol concentration (BEC) in the final product by 1°GL. The operating parameters which significantly influenced the BEC are concentration of cell in pre-fermentation (PFM), water fermentation pH (WFMpH), and water fermentation hardness (WFH). An increase of 8.45% in BEC was obtained for Sugar mill, India.

Life Cycle Greenhouse Gas Emissions of Brazilian Sugar Cane Ethanol Evaluated with the GREET Model Using Data Submitted to RenovaBio.

Brazil is the second-largest ethanol producer in the world, primarily using sugar cane as feedstock. To foster biofuel production, the Brazilian government implemented a national biofuel policy, known as RenovaBio, in which greenhouse gas (GHG) emission reduction credits are provided to biofuel producers based on the carbon intensities (CI) of the fuels they produce. In this study, we configured the GREET model to evaluate life cycle GHG emissions of Brazilian sugar cane ethanol, using data from 67 individual sugar cane mills submitted to RenovaBio in 2019/2020. The average CI per megajoule of sugar cane ethanol produced in Brazil for use in the U.S. was estimated to be 35.2 g of CO2 equivalent, a 62% reduction from U.S. petroleum gasoline blendstock without considering the impacts of land use change. The three major GHG sources were on-field N2O emissions (24.3%), sugar cane farming energy use (24.2%), and sugar cane ethanol transport (19.3%). With the probability density functions for key input parameters derived from individual mill data, we performed stochastic simulations with the GREET model to estimate the variations in sugar cane ethanol CI and confirmed that despite the larger variations in sugar cane ethanol CI, the fuel provided a robust GHG reduction benefit compared to gasoline blendstock.

Impact on Mahamaya Sugar mill due to Ground Vibration and Air Overpressure in Jagannathpur opencast coal mine

Impact on Mahamaya Sugar mill due to Ground Vibration and Air Overpressure in Jagannathpur opencast coal mine

Performance evaluation of bagasse-based cogeneration power generation plant utilizing IFLT, IF-FMEA and IF-TOPSIS approaches

PurposeTo meet energy demand and tackle the challenges posed by global warming, Bagasse-based Cogeneration Power Generation (BCPG) plant in sugar mills have tremendous potential due to large-scale supply of renewable fuel called bagasse. To meet this goal, an integrated framework has been proposed for analyzing performance issues of BCPG.Design/methodology/approachIntuitionistic Fuzzy Lambda-Tau (IFLT) approach was implemented to compute various reliability parameters. Intuitionistic Fuzzy Failure Mode and Effect Analysis (IF-FMEA) approach has been implemented for studying risk issues results in decrease in plant's availability. Moreover, IF- Technique for Order Performance by Similarity to Ideal Solution (IF-TOPSIS) is implemented to verify accuracy of IF-FMEA approach.FindingsFor membership and non-membership functions, availability decreases to 0.0006% and 0.0020% respectively for spread ±15% to ±30%, and further decreases to 0.0127% and 0.0221% for spread ±30% to ±45%. Under risk assessment failure causes namely Storage tank (ST3), Valve (VL6), Transfer pump (TF8), Deaerator tank (DT11), High pressure heater and economiser (HP15), Boiler drum and super heater (BS22), Forced draft and Secondary air fan (FS25), Air preheater (AH29) and Furnace (FR31) with Intuitionistic Fuzzy Hybrid Weighted Euclidean Distance (IFHWED) based output scores – 0.8988, 0.9752, 0.9400, 0.8988, 0.9267, 1.1131, 1.0039, 0.8185, 1.0604 were identified as the most critical failure causes.Research limitations/implicationsReliability and risk analysis results derived from IFLT and IF-FMEA approaches respectively, to address the performance issues of BCPG is based on the quantitative and qualitative data collected from the industrial experts and maintenance log book. Moreover, to take care of hesitation in expert's knowledge, IF theory-based concept is incorporated so as to achieve more accuracy in analysis results. Reliability and risk analysis results together will be helpful in analyzing the performance characteristics and diagnosis of critical failure causes, which will minimize frequent failure in BCPG.Practical implicationsThe framework will help plant managers to frame optimal maintenance policy in order to enhance the operational aspects of the considered unit. Moreover, the accurate and early detection of failure causes will also help managers to take prudent decision for smooth operation of plant.Social implicationsThe results obtained ensure continuous operation of plant by utilizing the bagasse as fuel in boiler and also mitigate the wastages of fuel. If this bagasse (green fuel) is not properly utilized, there remains a dependency on coal-based power plants to meet the power demand. The results obtained are useful for decreasing dependency on coal, and promoting bagasse as the green, and alternative fuel, the emission by burning of these fuels are not harmful for environment and thereby contribute in preventing the environment from harmful effect of GHGs gases.Originality/valueIFLT approach has been implemented to develop reliability modeling equations of the BCPG unit, and furthermore to compute various reliability parameters for both membership and non-membership function. The ranking results of IF-FMEA are compared to IF-TOPSIS approach. Sensitivity analysis is done to check stability of proposed framework.

Facile synthesis of robust Ag/ZnO composites by sol–gel autocombustion and ion-impregnation for the photocatalytic degradation of sucrose

Metallic Ag nanoparticles decorated on ZnO photocatalysts were prepared by facile sol–gel autocombustion followed by ion-impregnation. Electron microscopy studies revealed the presence of impregnated Ag as nanoparticles on ZnO surfaces, which affected the microstructure of ZnO particles. XRD patterns of Ag/ZnO composites confirmed the metallic phase of Ag. No peak shift for ZnO phase peaks suggests that the impregnated Ag was barely incorporated into the ZnO lattice. Consequently, DRS spectra of Ag/ZnO composites revealed the same absorption edges and Eg for pure and Ag/ZnO. The photocatalytic activity of Ag/ZnO composites for sucrose degradation under UV light was 40% higher than that of pure ZnO. Metallic Ag nanoparticles on the ZnO surface suppressed the surface defects and the recombination of photoexcited electrons and holes. The highest activity with 100% degradation of 100 ppm sucrose (1200 µg of carbon) within 105 min was achieved using ZnO with 10% w/w Ag (10% Ag/ZnO). Ag L3-edge XANES spectra of fresh and spent Ag/ZnO catalysts confirmed the stability of metallic Ag after the usage. The Ag/ZnO catalyst could be used for 5 cycles without losing photocatalytic activity. The Ag/ZnO catalyst was utilized to degrade sugar-contaminated condensate from the sugar mill. 10% Ag/ZnO revealed the highest photocatalytic performance, capable of degrading 90% of sugar in the condensate within 90 min.

Economic comparison of decentralized versus centralized processing of sugarcane to fructooligosaccharides and ethanol

AbstractThe global sugarcane industry is under threat due to low international prices and oversupply. This requires new revenue opportunities through a diversification strategy. The economic competitiveness of small‐scale, decentralized biorefineries to produce short‐chain fructooligosaccharides (scFOS) and/or ethanol, both valuable products with growing market applications, in comparison to large‐scale, centralized facilities annexed to existing sugarcane mills, was therefore considered. The economic feasibility of three potential scenarios was investigated using AspenPlus process simulations of small‐ and large‐scale facilities. In Scenario 1 only scFOS was produced. In Scenario 2 only ethanol was produced, and in Scenario 3 scFOS and ethanol were co‐produced. The small‐scale implementation of Scenarios 1 and 3 was economically feasible, with minimum selling prices (MSPs) below market prices. However, in all scenarios the large‐scale implementation of technologies in facilities annexed to an existing sugar mill improved economic viability, despite efforts to minimize the disadvantages of small‐scale facilities and their capital costs through the selection of simplified process technologies and decentralized processing. Despite this, the small‐scale production of scFOS is the preferred investment option for scFOS production due to the very high scFOS production rates of the large‐scale scenarios, which could flood the market. Processing of freshly harvested sugarcane in decentralized, small‐scale facilities increased the feedstock cost per unit of sugar, in comparison with the use of molasses obtained by annexation to an existing sugar mill. Simplified sugarcane processing to ethanol also lowered the product yield and increased capital costs. Further improvements in process technology design and performance for small‐scale facilities are required to make these financially competitive with large‐scale facilities.

Assessment of in situ stabilization and heavy metal toxicity reduction of sugar mill pressmud through pilot scale composting.

Owing to a huge amount of industrial organic waste generation in the recent past, concerned industries are facing immense challenges for in situ treatment and disposal of such wastes. Therefore, in this study, the efficacy assessment of in situ windrow composting of pressmud (PM) produced by sugar industry has been investigated. Samples were grabbed and mixed from windrows having composting days of 15 (PM15), 30 (PM30), and 45 (PM45) and were collected along with a compost sample from the 60th day (PMC) windrow. An investigation of physico-chemical parameters including pH, electrical conductivity, moisture content, volatile solids (VS), ash content, biochemical oxygen demand, chemical oxygen demand, total nitrogen, and C/N ratio was performed for raw PM and other aforementioned samples. Moreover, speciation of heavy metals (Cu, Cr, Ni, Pb, Cd, and Zn), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic analyses were performed for PM and PMC to evaluate the heavy metal toxicity and mineralogical and chemical changes. The analysis showed 20.33% reduction in VS content and 53.65% increase in TN content after 60 days of in situ windrow composting. The pH and EC values of PMC were found to be lesser than that of upper values recommended for agricultural purposes. Furthermore, the speciation analysis showed significant reduction in bioavailability of heavy metals. The XRD and FTIR results were confirmatory for transformation of heavy metals into relatively stable forms. The study recommends the windrow composting practice as effective bioconversion technique that stabilizes organic content, enhances humification, and diminishes heavy metal bioavailability for PM and similar other sludges.

‘No commercial activity leaves greater benefit’: The profitability of the Cuban‐based slave trade during the first half of the nineteenth century

AbstractIn this paper, we discuss the basis of the illegal slave trade between Africa and Cuba, measuring its volume and profit during the first half of the nineteenth century. Due to its illegal nature, the sources for exploring this trade were systematically destroyed, but we have been able to locate the accountancy of 17 expeditions that gives us a comprehensive understanding of the profits, margins, and risks. The basis to understanding this business was the murderous use of enslaved persons in the sugar mills, which forced a continuous repositioning through an illegal, although tolerated by the Spanish authorities, business. We demonstrate that from an economic point of view, the slave trade after illegalization was highly profitable, as the financial return of successful expeditions was near 100 per cent of the invested capital in less than a year. The risk of capture by the British authorities, associated with its illegal nature, was only high during the initial moments, and became steadily lower afterwards. In terms of volume, the trade of a half million enslaved persons illegally smuggled into Cuba produced what was probably the island's most important market.

Falling-film evaporators – role in steam saving (a perspective of Almoiz Industries, Pakistan)

The energy efficiency of a sugar mill depends to a large extent on the performance of the evaporators. Falling-film evaporators (FFEs) have the required characteristics to work on a narrow ΔT to improve the steam economy. Almoiz Industries set up a state-of-the-art project in Pakistan having a low steam and power consumption. A complete set of seven FFEs was installed. Operational problems such as scaling are discussed. All vapors from the 1st effect to the 5th, including condensate, are used to heat juice and crystallize sugar to reduce steam consumption. A steam consumption of 35 kg/100 kg of cane and 33 kW/t of cane electrical consumption is achieved at the maximum rate of cane crushing. Operational data over the last campaigns are given. Saved bagasse can be used for power export and other allied businesses.

Effect of continuous sugarcane bagasse-derived biochar application on rainfed cotton (Gossypium hirsutum L.) growth, yield and lint quality in the humid Mississippi delta

Optimizing soil health through soil amendments is a promising strategy for enhancing rainwater efficiency for stabilizing crop production. Biochar, obtained by torrefaction of sugarcane bagasse, a byproduct from sugar mills, has a high potential for its use as a soil amendment, which can boost crop yields, but needs further field trials for its adoption in farming systems. A field study was conducted during 2019–2021 at Stoneville, Mississippi, to assess rainfed cotton (Gossypium hirsutum L.) production under four biochar levels (0, 10, 20, and 40 t ha−1) on Dundee silt loam soil. The effects of biochar on cotton growth and lint yield and quality were examined. Biochar levels had no significant impact on cotton lint and seed yield for the first two years. Still, in the third year, a significant increase in lint yield by 13 and 21.7% was recorded at 20 and 40 t ha−1 biochar levels, respectively. In the third year, lint yields were 1523, 1586, 1721, and 1854 kg ha−1 at 0, 10, 20 and 40 t ha−1 biochar levels, respectively. Similarly, cotton seed yield increased by 10.8% and 13.4% in 20 and 40 t ha−1 biochar plots. This study demonstrated that successive biochar applications at 20 or 40 t ha−1 can enhance cotton lint and seed yields under rainfed conditions. These improved yields with biochar did not produce increased net returns due to the increased production costs. Many lint quality parameters were unaffected except for micronaire, fiber strength and fiber length. However, potential long-term benefits of enhanced cotton production from biochar application beyond the length of the study merit further investigation. Additionally, biochar application is more relevant when accrued carbon credits through carbon sequestration outweigh the increased production costs due to biochar application.

My father put them up there: Anthropogenic environmental change associated with abandoned river vessels in the Clarence River, NSW, Australia

AbstractThe Clarence River (New South Wales, Australia) was the main transport corridor for the timber and sugar cane industries operating in the catchment from the 1860s to the 1970s. Using archaeological, documentary, and oral historical resources we explore some of the anthropogenic impacts of these industries upon the fluvial geomorphology of the lower Clarence River. In particular, the deliberate abandonment of obsolete vessels on the river system is a focus. These discarded former cane and timber barges have been used as erosion control devices in several areas around the Harwood Island sugar mill, resulting in the accumulation of sediments and the establishment of mangrove environments in what were degraded areas.