Swine manure treatment technologies as drivers for circular economy in agribusiness: A techno-economic and life cycle assessment approach.

Anaerobic digestion has been employed as a technology capable of adding value to waste coupled with environmental impact mitigation. However, many issues need to be elucidated to ensure the systems viability based on this technology. In this sense, the present study evaluated technically, environmentally, and economically, four configurations of swine waste treatment systems focused on the promotion of decarbonization and circularity of the swine chain. For this, a reference plant, based on a compact treatment process named SISTRATES® (Portuguese acronym for swine effluent treatment system) was adopted to serve as a model for comparison and validation. The results showed the importance of prioritization of the energy recuperation routes through anaerobic digestion, providing increased economic benefits and minimizing environmental damage. Thus, the SISTRATES® configuration was the one that presented the best designs in a circular context, maximizing the recovery of energy and nutrients, along with the reduction of greenhouse gas emissions, ensuring the sustainability of the pig production chain.

Assessment of a tannin-based organic polymer to harvest Chlorella vulgaris biomass from swine wastewater digestate phycoremediation.

This study investigated the efficiency of an organic tannin polymer alone or amended with polyacrylamide to harvest Chlorella vulgaris biomass grown in a laboratory-scale photobioreactor treating swine wastewater digestate. The effect of biomass concentration, tannin (TAN) dosages and changes in pH were evaluated in jar test experiments. Among the TAN concentrations tested (11, 22, 44, 89, 178 mg L(-1)), 11 mg L(-1) showed the highest biomass recovery (97%). The highest coagulation/ flocculation efficiencies were obtained at pH 5 to 7. Flocculation efficiency improved from 50 to 97% concomitant with the increasing biomass concentrations from 45 to 165 mg L(-1), respectively. Recovery efficiencies above 95% were achieved with the same TAN dosage (11 mg L(-1)) irrespective of the concentration of organic carbon present (75 to 300 mg TOC L(-1)). Overall, the results suggest that TAN could become an interesting alternative choice of non-toxic organic polymer for harvesting Chlorella sp. from organic-rich wastewater.

Performance of two swine manure treatment systems on chemical composition and on the reduction of pathogens.

Swine effluents must be correctly handled to avoid negative environmental impacts. In this study, the profiles of two swine manure treatment systems were evaluated: a solid-liquid separation step, followed by an anaerobic reactor, and an aerobic step (System 1); and a biodigester followed by serial lagoons (System 2). Both systems were described by the assessment of chemical, bacterial and viral parameters. The results showed that in System 1, there was reduction of chemicals (COD, phosphorus, total Kjeldhal nitrogen - TKN - and NH(3)), total coliforms and Escherichia coli; however, the same reduction was not observed for Salmonella sp. Viral particles were significantly reduced but not totally eliminated from the effluent. In System 2, there was a reduction of chemicals, bacteria and viruses with no detection of Salmonella sp., circovirus, parvovirus, and torque teno virus in the effluent. The chemical results indicate that the treated effluent can be reused for cleaning swine facilities. However, the microbiological results show a need of additional treatment to achieve a complete inactivation for cases when direct contact with animals is required.

Advanced swine manure treatment and utilization in Brazil.

Animal production has changed from subsistence to an industrial model, lowering production costs but giving rise to higher potential environmental impact. When the effluents are not correctly managed, serious pollution events can occur. In Brazil liquid manure is commonly stored in reception pits or covered lagoons (biodigestors), followed by land application as a biofertilizer. In some regions there is an excess of manure due to low soil support capacities, and in these cases new technologies have to be adopted to export or treat the excess effluent. Manure storage time in pits/covered lagoons and new polymers to separate the solid fraction have been studied in Brazil. Treatment technologies, like swine manure treatment systems (SMTS), have been developed from a technical and economical point of view to optimize the processes and give a technological alternative to pork producers increasing production while reducing environmental impact.

Effect of storage time on swine manure solid separation efficiency by screening.

Confined animal feeding operations (CAFOs) have suffered considerable transformations since the last decade in Brazil, because of increasing of their production scale. Swine production is following this same trend, and the volume of manure produced and the form that is managed has a direct impact on houses air quality and efficiency of treatment systems. The objective of this work was to study the manure solid-liquid separation efficiency by screening, subject to different screen opening sizes and pit disposal time under tropical climate conditions. An ammoniacal nitrogen producing rate of 24 mg/L per storage day was observed and a decrease in screen separation efficiency in the first eight days of storage, obtained by solid group analysis. The storage time influenced directly the degradation of organic fraction indicated by the chemical oxygen demand increase overtime. The results suggest that the efficiency of solid-liquid separation is increased when carried out with the shortest storage time.

The retinal irradiance and spectral properties of the multiport illumination system for vitreous surgery.

The multiport illumination system was developed as a fiberoptically illuminated pars plana cannula system for vitreous surgery. The retinal irradiance of the multiport illumination system and several other commonly used endoilluminators (light pipes) measured at 5 mm are comparable, ranging from 94 to 256 mW/cm2. In the actual surgical setting, however, the retinal irradiance of the multiport illumination system is far less (56 mW/cm2) because the end of the fiberoptic cables are fixated in the pars plana 16.5 mm away from the retinal surface. A reduction in the maximal intensity (100%) to 50% reduces the retinal irradiance by approximately two thirds to 3.7 mW/cm2. The light emitted by the multiport illumination system used in conjunction with a long-wave pass filter with a cutoff wavelength of 420 nm reduces the amount of short-wavelength light by one third to about 4% of the overall irradiance.

Symptomatic abnormalities of dark adaptation in patients with age-related Bruch's membrane change.

Some patients with age-related changes at the level of Bruch's membrane and good visual acuity report poor vision in dim light, fading vision in bright light, and a central scotoma noticeable in the dark. Ophthalmic examination, scotopic thresholds, and dark adaptation kinetics were recorded in 12 eyes of 12 patients with such symptoms. All had macular drusen which were hypofluorescent on fluorescein angiography in nine subjects, and six had evidence of prolonged choroidal filling on fluorescein angiography. Scotopic thresholds were depressed in six patients who all experienced a central scotoma in the dark or poor night vision. The kinetics of dark adaptation were abnormal in all 10 patients in whom reliable measurements were possible. The findings suggest that visual symptoms reflect abnormality of both scotopic sensitivity and the time course of dark adaptation in patients with age-related Bruch's membrane change.

Abnormal dark adaptation and rhodopsin kinetics in Sorsby's fundus dystrophy.

Scotopic visual thresholds and time courses for dark adaptation were determined in eight patients with Sorsby's fundus dystrophy. Rhodopsin regeneration also was recorded in two. All patients had poor night vision and a visible yellow deposit at the level of Bruch's membrane that was confluent in the posterior pole. In retinal regions with the yellow deposit, scotopic thresholds were elevated, the rod-cone break was delayed or indistinct, the time courses for the rod portion of the dark adaptation curve was prolonged, and rhodopsin regeneration was slow in the one patient in whom measurements were made. In regions of ophthalmoscopically normal retina, dark adaptation was affected minimally, and in one patient, rhodopsin was regenerated at a normal rate. It was hypothesized that the abnormal dark adaptation and rhodopsin kinetics might be caused by reduced metabolic exchange across a thickened Bruch's membrane.

Histopathology of incipient fundus flavimaculatus.

A 9-year-old boy was diagnosed with fundus flavimaculatus in his left eye. The boy's fellow eye was enucleated at 16 months of age for retinoblastoma. The authors reviewed the material submitted for histopathologic examination and found that the retinal pigment epithelial cells demonstrated increased autofluorescence and increased reactivity to periodic acid-Schiff staining. Many cells had their melanin granules displaced toward the cell apex. The retinal pigment epithelial changes are consistent with previous histopathologic findings in fundus flavimaculatus and imply that the structural changes are seen in early life.

Treatment of cystoid macular edema with acetazolamide in a patient with serpiginous choroidopathy.

A patient with serpiginous choroidopathy had decreased visual acuity and cystoid macular edema. He was treated with acetazolamide, a carbonic anhydrase inhibitor. After 2 weeks of treatment, the patient's visual acuity improved and there was complete resolution of the cystoid macular edema. Improvement in extrafoveal scotopic retinal sensitivity was documented.

Posterior vitreous cyst.

We observed two patients who had unilateral posterior vitreous cysts; one patient had been observed for 17 years. Both patients were young females who reported transient, infrequent obscurations of vision that were not disabling. One involved eye was emmetropic, and the other was highly myopic. No other ocular abnormalities were present. In the patient observed for 17 years, the physical characteristics of the posterior vitreous cyst remained unchanged. With this stable clinical course, posterior vitreous cyst that does not visually disable the patient may be managed by periodic observation.

The successful removal of a subretinal cysticercus by pars plana vitrectomy.

A 39-year-old woman from Belize presented with recent vision loss in her left eye due to a subretinal cysticercus located near the macula. We are reporting the use of standard vitrectomy instrumentation and techniques to successfully remove the subretinal cysticercus by a transretinal approach. Pars plana vitrectomy with transretinal removal of the cysticercus is a useful alternative to the traditional external sclerotomy.

Melanocytoma: nomenclature, pathogenesis, natural history and treatment.

A melanocytoma (magnocellular nevus) is a benign pigmented tumor that may arise wherever uveal melanocytes are present. The most commonly observed site is on or adjacent to the optic nerve head. In the past this tumor was frequently misdiagnosed as a malignant melanoma and many unnecessary enucleations were carried out. Its clinical features are now well recognized and, fortunately, specimens of melanocytomas are rarely received in ocular pathology laboratories today. A review of the literature concerning this tumor is presented, with special reference to the changing concepts in nomenclature, pathogenesis, natural history, and treatment that have evolved in the past one hundred years. We also define the clinical and histopathological features of this tumor.

Malignant transformation of an optic nerve melanocytoma.

A 47-year-old woman who had had a flat, hyperpigmented lesion of the optic disc and juxtapapillary choroid for at least 17 years experienced acute visual loss. This was caused by rapid growth of a pigmented tumour emanating from the original lesion. Histopathological examination of the enucleated globe revealed a large malignant melanoma originating from a melanocytoma (magnocellular nevus) within the optic nerve and peripapillary choroid. This case represents a very rare instance of malignant transformation of a normally benign tumour.

Phacoanaphylactic endophthalmitis associated with extracapsular cataract extraction and posterior chamber intraocular lens.

We describe the clinicopathologic findings in a patient who underwent extracapsular cataract extraction (ECCE) with insertion of a posterior chamber intraocular lens (IOL). The patient had a sterile hypopyon and anterior uveitis that temporarily subsided but recurred. The inflammation actually worsened after removal of the IOL, and the eye was enucleated. Histopathologic examination showed a pattern consistent with phacoanaphylactic endophthalmitis. We therefore postulate that the patient's complications were due to hypersensitivity to her own lens protein, which remained after the ECCE, rather than to the IOL itself.