Tinjauan Aspek Teknis Pemilihan Media Biofilter Untuk Pengolahan Air Limbah

There are literally dozens of different types of biofilters used for wastewater treatment applications. While many have common features, some are fundamentally different from the rest. The purpose of this article is to educate the reader about the types of packings used for fixed film biofilters.The types of biofilters under discussion are filters that employ a non-moving surface area to provide a substrate for various bacteria to attach and grow. The substrate remains in place while the water flows through the system. The heart of these biofilters is the packing or media used to provide the surface area. The type of packing used strongly influences both the capital and operating costs of the biofilter. It is important to emphasize however, that the packing merely provides surface area for bacteria to colonize. It is the bacteria that do the actual work of the biofilter. In order for the bacteria to do their job effectively, the biofilter and packing design must provide an even distribution of nutrients and oxygen while removing dissolved and suspended waste products. Most biofilters utilize aerobic bacteria but it is also possible to design and operate anaerobic systems for special purposes. Various types of packings exist for fixed film biological filters. Each different type has advantages and disadvantages but in terms of overall cost and suitability, the structured packings are the best choice for commercial biofilter designs

Mikroorganisme Patogen dan Parasit di dalam Air Limbah Domestik Serta Alternatif Teknologi Pengolahan

Domestic waste are known to be a potential pollutant due to its\u27 organic and inorganic content. It is also harmful for society for its pathogenic microorganism contents such as pathogenic bacteria, viruses, parasitic worms, parasitic protozoa, etc. The lack of domestic waste processing facilities is contributing to the increasing seriousness of this matter.One of the alternative ways to amend the problem is to process the waste individually or semi-communally by utilizing an aerobic-anaerobic biofilter process. Some of the advantage of utilizing this process is: easy maintenance, low operation cost, relatively lower sludge compared to the activated sludge process, can remove nitrogen and phosphorus, relatively lower air supply requirement for aeration, applicable in processing waste water with large amount of BOD and it can also remove suspended solid (SS). Results gained from experiments of the “Aerobic-Anaerobic Biofilter Combination” tool prototype, used for processing domestic waste showed that with a hydraulic retention time of 1 to 3 days and a Hydraulic re-circulation ratio (HRR) of 1, is a highly efficient process which is: BOD 84.7% - 91%, COD 79.6%-95.3%, SS 94.1% - 95%, Ammonia (NH4-N) 89.3%-89.8%, Detergent (MBAS) 83% - 87% and phosphate (PO4) 44,4% - 47.3%

Palladium-induced granulomas analysed with inductively coupled plasma mass spectrometry

Dermatology-oncolog

Tissue-Sparing Excision for Skin Lesions Located on the Lower Limb

Dermatology-oncolog

Tunneled transposition flap for conchal defect

Dermatology-oncolog

Challenging Repair of a Helical Rim Defect

Dermatology-oncolog

The Compressiometer: Toward a New Skin Tensiometer for Research and Surgical Planning

After surgery, around 35% of patients experience problems of excessive scarring, causing disfiguring and impaired function. An incision placed in the wrong direction causes unnecessary skin tension on the wound, resulting in increased collagen disposition and potentially hypertrophic scars. Currently, skin tension lines are used for incision planning. However, these lines are not universal and are a static representation of the skin tension that is in fact under influence of muscle action. By designing a new skin force measurement device the authors intend to make research on dynamic skin characteristics possible and to objectify incision planning and excision closure planning. The device applies a known compressive force to the skin in standardized directions and measures the displacement of the skin. This allows users to measure the skin reaction force in response to compression and to determine the optimal incision line or best wound closure direction. The device has an accuracy of 96% and a sensitivity of < 0.01 mm. It is compact, works non-invasively and standardizes measurement directions and is therefore an improvement over previously designed skin tensiometers

Risk factors for incomplete excision of cutaneous squamous cell carcinoma: a large cohort study

Background The standard treatment for cutaneous squamous cell carcinoma (cSCC) is surgical excision. Failure to radically remove a cSCC is a risk for recurrence, progression and metastasis. Objectives This study investigates several risk factors for incomplete excision of cSCC. Methods All consecutive patients in a single institution treated with wide local excision for primary cSCC over a 10-year period were included in this study. Risk factors such as: gender, age, immunosuppression, tumour size, location, differentiation grade, tumour depth, perineural and lymphovascular invasion (PNI and LVI) were extracted from the database. Univariable and (if applicable) multivariable logistic regression analysis were used to identify risk factors (P < 0.05). Generalized estimating equations (GEEs) were used for multiple tumours within the same patients. Results A total of 566 patients with 1159 cSCC were identified. Univariable and multivariable logistic regression analysis showed that depth beyond the dermis (OR: 5.7 95% CI: 3.1-10.5) was the only risk factor for incomplete excision of cSCC. Immunosuppression was only a risk factor in the deep plane (OR: 2.5, 95% CI: 1.3-4.6). Conclusion Tumour depth beyond the dermis is the most important risk factor for incomplete excision of cSCC. Immunosuppression is a risk factor in the deep plane but its relevance is uncertain. Immunosuppression is not consistently included in the current cSCC staging systems, but care should be taken when treating these patients

Osteochondral defects of the talus: a novel animal model in the goat

Osteochondral defects of the talus pose a difficult therapeutic challenge. An experimental animal model of the ankle joint is not available. The aim of this study was to test a newly developed animal model for osteochondral defects of the ankle in vivo. Osteochondral defects were created in the talus of goat hind legs using a posterolateral surgical approach. The defects were filled with either autologous cancellous bone or donor demineralized bone matrix or left empty as control. After 12 weeks of healing, the specimens were analyzed with radiography, macroscopy, microcomputed tomography, histology, histomorphometry, and fluorescence microscopy. It was possible to create a standardized defect in each talus. The implanted material remained in place. The analyses showed that most bony tissue was generated in the defects filled with autologous bone and least in the control defects. Our findings show that a standard osteochondral defect can be created in the talus by a relatively simple procedure in a large animal that allows qualitative and quantitative evaluation. The model can be used in future experiments to investigate alternative treatment methods before they are introduced into clinical practice